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[Question] [ So, there's a closed question [So we have aliens in orbit. Now what?](https://worldbuilding.stackexchange.com/questions/9593/so-we-have-aliens-in-orbit-now-what) - but there's an implied assumption: That somehow, there will be some unified / coherent response from humanity to aliens in orbit. I find that **extremely** unlikely. People in mass, can't even keep their laser pointers to themselves, even when asked too and when it's clearly in everyone's benefit. There's always some yahoo out there who feels self-entitled enough to use *his* laser pointer to mess around. Writ large on a planet with 7 billion people, and a fairly large first world population who have lasers, radios, model rockets, etc, etc. Granted, most humans in current society will be unable to get to LEO or GEO, for a face-to-face meeting. But, I see no way of keeping every religious cult, random nut-job, or yahoo from trying to contact aliens in orbit. And/or impersonating (or trying to) important people. I mean, you find an African-American actor and have him claim to be Obama (or for other movers and shakers: old Asian dude in glasses; or middle-aged Latin-American dude with a goatee), and put it on a tight-beam directed at the alien ship. **How would you have (in your story) a legitimate government / official-dom get their signal recognized from all of the chatter aimed at an alien ship?** (or would you even bother? - Maybe you'd wait for them to contact you?) Pouring more power into your signal seems like, screaming "**I** am the King!"... if you have to say it... well. [Answer] Send the signal from the ISS. The aliens should be well capable of detecting directionality of the signal, at least to a precision sufficient to distinguish Earth-based from LEO-based. And considering the ISS is one of the greatest scientific endeavors of Earth (easily observable), the crew can be trusted to behave in a responsible manner and forward the right messages. Once public keys of 'authorized entities' of Earth, along with algorithms, have been passed from ISS, the communication can switch to direct channels, the signatures of the messages confirming authenticity. [Answer] [VSauce has an interesting video](https://www.youtube.com/watch?v=gCBlAAtJA54) where he talks about the two established, international organizations who are already set up to handle this, [SETI](http://www.seti.org/) and the [UN Office for Outer Space Affairs](http://www.unoosa.org/oosa/COPUOS/copuos.html). While the UNOOSA denies having the authority to speak for Earth, if aliens show up the expectation is they'd be the ones everyone would look to coordinate our response. In a panic, governments like using established structures who have been thinking about the problem for a long time. The UNOOSA would look to SETI for help, who have been thinking about and waiting for this for a very long time. [SETI has developed a plan "following the detection of extraterrestrial intelligence"](http://www.seti.org/post-detection.html) which would likely form the framework for our official response. It includes... > > 8. No response to a signal or other evidence of extraterrestrial intelligence should be sent until appropriate international consultations have taken place. The procedures for such consultations will be the subject of a separate agreement, declaration or arrangement. > > > Their official line is to keep quiet until we all talk about it. Assuming they agree, that would keep all of the major governments and institutions quiet (if they don't agree, then there is no legitimate official communications). That covers nearly everyone with access to a powerful, directional radio antenna. Maybe Earth will have to come up with the Intergalactic version of "*please hold, your call is very important to us...*" What about rogue signals? Anything below a certain amount of power will be lost in the noise. What noise? Our noise. We emit a lot of electromagnetic noise into space. Some of it is chaotic, but a lot of it is patterned... communications. However, it is all patterned differently as we use dozens and dozens of different protocols. Ironically, some of our most important communications will look like random noise because they are encrypted. The aliens will have been observing this for some time as they approach. If they do not understand the content, they will understand that it is intelligent. However, the overall pattern will be chaotic from many sources and in many forms. Whether or not they will recognize this means we are not unified is speculation, but they will recognize that random electromagnetic chatter is normal. Having some yahoo bounce the digits of Pi off their ship with a relatively low power laser isn't likely to seem out of the ordinary. Nor are they likely to communicate anything intelligible to the aliens beyond basic math, not before the rest of the Earth gets its act together. We don't know what part of the electromagnetic spectrum they're observing, how they're using it (AM or FM or something else?), or if they're even using electromagnetism at all! If they knew how to finely manipulate gravity waves how we manipulate EM we could be staring dumbly at each other for a while. The only rogue nation with a space program capable of powerful communications is North Korea (Iran could probably do it, but they're not as rogue as the US paints them to be) who would be the wild card. However we're safe in that North Korean scientists are not going to crack the code before everyone else does. We're double safe in that the messages will likely be internally politically focused narcissistic gibberish. "Here is a JPEG of our Dear Leader!" When Earth responds, they must do something out of the ordinary to get noticed. They must order the chaos, that's a clear sign of intelligence. Individual governments and institutions, guided by the UN on the advice of SETI, would *all* point their transmitters at the alien ship and *simultaneously* broadcast the same message. This is unprecedented in the history of humanity. One group transmitting with the most power is like shouting "*LISTEN TO ME, I AM THE LOUDEST*", but having multiple sources all over the planet sending the same signal says > > *Listen to us, our voice is unified*. > > > [Answer] It seems to me that the aliens would have access to our broadcasts, and be able to monitor our television and radio not just after they arrive but while they are approaching. Sufficiently advanced computing technology would have translation software working by the time they reached orbit. Once in orbit they can also try and piggy back into the Internet by reverse engineering the protocols and intercepting some satellite up-links. Between these two sources of information it shouldn't take them long to understand our political makeup and work out who would be appropriate to contact depending on their long term goals. [Answer] **Who can speak on behalf of Earth?** I know I am posting "non-answer" but I still have to: We have [United Nations](http://en.wikipedia.org/wiki/United_Nations) which could be the closest to "Earth representation" as we can get. But I doubt that UN has technology to communicate to space. And getting this huge organisation into agreement what should be done can take *too long.* So, sadly, we have to put them out of equation and ask differently: **Who has power to communicate?** Simply put, *anyone*. Leading powers would have some upper hand and for simplicity, lets put these powers in mind: India, USA, Europe, China and even North Korea. And it gets worse: Big media houses. They have commercial satellites and they would sell their moms for possibility to broadcast alien communication on live TV. Imagine the prices for advertisement! Huge profit! **Who has power to take aliens down?** USA, China, Russia, India and even North Korea. Hope I did not miss anyone important. Good luck having them all agree to not shoot on the aliens. Especially if aliens look *ugly and dangerous* Sadly, your question has only one plausible solution: **What do aliens know about us? What is their motivation?** Did they come in person, because we did not get [their response](http://rationalwiki.org/wiki/Arecibo_answer) in first place? Are we interesting insect to investigate further? Is our planet valuable resource for them? Several ideas: *Comedy/Parody*: For whatever reason, the aliens could catch only North Korea state TV broadcast. They come to see glorious leader Kim Jong-Un to salute him in his awesomeness. Boil down the story in several misunderstandings. *Drama* Earth is valuable resource. They have no motive in talking to us in first place. They came to kill us all. *Sci-fi* It is simple "first contract". From story perspective, it would be interesting to make aliens believe that your country represents Earth as whole and your "leader" is the one with power to represent the whole Earth. Spend some time into investigating, what other countries might think and do. [Answer] The usual method to guarantee the identify of the source of a message is cryptography and it's related areas. All correct answers will revolve around this. The three pillars of information security are : Confidentiality : Guarantee that only those who are entitled to read the messages are able to do so. Reliability : Guarantee that the message will be delivered when needed. Identity : Guarantee that those which the message identify as authors are trully the authors of the message. So, it follows on from information security practice, that the most usual way to guarantee those pillars are those methods based on cryptography. By, for one, encrypting each message with a public key cryptography method, you can guarantee (to a large degree) that the message was sent by the authorities that hold the valid key. The only final problem is key distribution. Aliens would need to exchange keys with earth's authorities in order to allow the identification of the message sources. This would, probably involve landing a spacecraft in front of the white house, just like in the movies. Another, less guaranteed way to deliver the message with some security about its sender, is to have your largest most powerfull transmiter point to space and send it. This is brute force, because, probably, your competitors (those wanting to send messages as if they were true authorities) would probably have less money to engenieer powerfull transmitters. But, in a multipolar world like ours, nothing prevents other national entities, besides USA, to build such transmitters and start to talking to the aliens, as if they where the USA, or vice versa. This might have political consequences that are out of the scope of this answer. [Answer] I think [Tim B's answer](https://worldbuilding.stackexchange.com/a/11335/7351) pretty well covers it, but I would assume that most governments, particularly super powers, like the US and China, would make an effort to employ [radio jamming](http://en.wikipedia.org/wiki/Radio_jamming) and other signal disruption in order to try and dominate the conversation. While the aliens may have decided that they would rather make contact with a particular government, some governments may attempt to hijack the conversation by deploying large scale jamming efforts. For instance if the aliens decided to contact China the US may decide that that is unacceptable and try to block their signal or vice versa... It would also be pretty likely that many governments would try to eliminate chatter by scrambling/jamming non-official signals within their own borders. [Answer] If human presence in space has progressed, they would study the behavior and see how Traffic Control / Port Authority is handled. It would be very rude to have a plasma exhaust cross a shipping lane, and they would need to learn a little about how things work. The legitimate authority is whom everyone else is taking orders from and coordinating through. If the contactor says "we'll send a pilot to guide you through the inner system" and one of the ships shows up as planned, that's a good sign. [Answer] Aliens wouldn't just tune into their radio to hear what our leader is saying. They would stay in orbit a while, maybe dodging a couple missiles (on Earth, humans studying animals aren't too off put by being attacked. Aliens could reasonably stay in orbit even if we provoke.) They would wait a long while, figure out our social structure, and then maybe try to communicate with multiple leaders. This is all assuming the aliens are advanced enough to actually form any sort of relationship with Earth. It could simply be a probe or something, not even capable of landing. In that case, it doesn't need to know who is boss. [Answer] In my story, I'd probably have the aliens have studied Earth broadcast media for a while, and figured us all out fairly well, at least as far as being able to understand something about our government organizations. And they'd probably want to engineer a big change to those baroque and corrupted systems. They'd probably use our government structures to identify the corrupting elements, and eliminate/dismiss/correct those one way or another, and start up their own new government structures for the earth, and detain and re-educate the corrupt when they showed up to that. In fact, the first government would probably mostly be made up of non-human Earthlings. Whales, orang-utans, giant sequoias, fungus, bee queens, elephants, octopi, ravens, etc. After all, clearly a LOT of affirmative action is in order! ]
[Question] [ For my non-European readers, here is an excerpt of what the [GDPR](https://en.wikipedia.org/wiki/General_Data_Protection_Regulation) means: (emphasis mine) > > The General Data Protection Regulation (GDPR) is a regulation in EU law on data protection and privacy for all individuals within the European Union (EU) and the European Economic Area (EEA). > > > **A processor of personal data must clearly disclose any data collection**, declare the lawful basis and purpose for data processing, how long data is being retained, and if it is being shared with any third-parties or outside of the EU. > > > I haven't been notified by Santa or his elves that he is collecting data about me. And mind you: my name and surname **are** my personal data, not to mention whether I have been good or naughty. Moreover, Santa also needs my full address to deliver my presents, and again, **that is also my personal data**. Santa hasn't notified me whether he is updating his Privacy Policy, so I assume that Santa stopped collecting this data, at least for Europeans. Does it mean that Santa is delivering me **nothing** this Christmas? If there is any way around this, can you please tell me what it is and how Santa can deliver me presents while still being compliant with the GDPR? Please assume I haven't been naughty. [Answer] **Santa's data collection has always been compliant with GDPR, so he has no need to change his ways.** The nature of his data collection is more transparent than most companies, and he is open to updating his records if you contact one of his representatives. For example, he makes it clear that he is operating in your town: > > You better watch out > > > You better not cry > > > Better not pout > > > I'm telling you why > > > **Santa Claus is coming to town** > > > The legitimate business purpose of his data collection is to create a list of those who are naughty and nice this year: > > **He's making a list** > > > And checking it twice; > > > **Gonna find out Who's naughty and nice** > > > Santa Claus is coming to town > > > He even gives some examples of what data he's collecting: > > He sees you when you're sleeping > > > **He knows when you're awake** > > > **He knows if you've been bad or good** > > > So be good for goodness sake! > > > --- The GDPR has some other requirements to it, [such as an EU-based representative](https://politics.stackexchange.com/questions/30509/how-are-gdpr-fines-actually-enforced-for-us-companies-with-no-physical-presence/30513#30513) being necessary for operating in the EU, allowing users to request data updates, and getting consent for data collected. Thankfully for Santa, he's been operating compliant representative systems for decades: Just go to any mall during the holiday season to meet with [a representative](http://tvtropes.org/pmwiki/pmwiki.php/Main/MallSanta). To ensure open and accurate records, the representative will ask the child if they've been naughty or nice that year and what type of present they want. As long as the child's parent/legal guardian is nearby to confirm the data change requests, Santa will be happy to update his database to ensure the naughty/nice data is accurate and that the requested presents are delivered. As for consent, the children are obviously too young to provide consent and must rely on their parent/guardian to consent to Santa's data collection. **I doubt there's a single house that is receiving presents from Santa without the parent's explicit consent**, and I'm sure we've all been told by our parents at some point to "be good or Santa won't give you presents this year!". [Answer] Santa is Christian priest (bishop as far as I remember). As you can see [here](https://edps.europa.eu/sites/edp/files/publication/16-02-25_personal_data_protection_church_warsaw_en.pdf) he is covered by exemption: > > The new Regulation will maintain the existing exemption which allows churches and other bodies with a 'religious... aim' to process sensitive data: > > > * 'in the course of its legitimate activities...'; > * '...with appropriate safeguards'; > * '...on condition that the processing relates solely to the members or to former > members of the body or to persons who have regular contact with it in connection with its purposes'; and > * on condition that 'the data are not disclosed outside that body without the > consent of the data subject'. > > > As no one ever saw his lists, and we don't know about any other activities, we can safely assume above bullets are met. [Answer] Well you are making a fundamental misunderstanding about the GDPR (as many have), that consent is the only basis for holding and processing information. There are actually [six legal bases](https://ico.org.uk/for-organisations/guide-to-the-general-data-protection-regulation-gdpr/lawful-basis-for-processing/#ib3) for holding data (you have to scroll down a little as the link doesn't work properly). Those six bases are: 1. Consent 2. Contract 3. Legal obligation 4. Vital interests 5. Public task 6. Legitimate interests So let's look at each of them and see if Santa has any basis for collecting our information. **Consent** - Actually this one may not even be as troublesome as it first seems. Presumably we're all writing letters to Santa asking for presents, this could potentially be seen as a form of consent for collecting our data, though I think that's a little iffy. **Contract** - The letter to Santa could also form the basis for a contract for the provision of services (present delivery), so I think this works. **Legal Obligation** - Unless you want to argue that Santa is legally obligated to perform his duties I don't think this one works. **Vital Interests** - No one is going to die if Santa doesn't do his job, probably doesn't work either. **Public Task** - I think this is a strong contender. From the website I linked above; "the processing is necessary for you to perform a task in the public interest or for your official functions, and the task or function has a clear basis in law." I would say the worldwide provision of joy and happiness is in the public interest, and the processing of our information is definitely required for Santa's official functions. **Legitimate Interests** - This is a little of a grey area and many businesses have used it as the basis for continuing to hold and process information, I see no reason why Santa couldn't do the same. So in short, there is no real issue at all and Santa can continue doing what he needs to do as long as he properly deals with our information and updates his privacy policies. [Answer] Santa already exempts himself from the petty concerns of local laws. He invades sovereign airspace each year and unlawfully enters private residences. The GDPR seems to be a lesser violation compared to others he willfully commits each year. Why should he concern himself with the GDPR? [Answer] ### Everyone gets the same present - a letter about sending your personal data This year we will all get a letter about the updated general terms and conditions and how you will be required to send a certain set of information to Santa so that he may send you your presents next year. Everyone will be required to send their address, name and age. You will also have to allow your parents to send Santa the data about you being nice or naughty. In case you don't want to disclose the naughty-or-nice information you will receive a generic probably-not-that-naughty present, which will most likely consist of old chocolate he found lying around in the elven workshops. Be careful to send your data as fast as you can. It will be harder to get into contact with Santa after the timeframe he had allocated for everyone to send in their address, name and age. If you don't send that information you will receive nothing because Santa is not allowed to use your address any longer. If he still sends you something you can sue him - and thereby make sure that lots of children will cry because they won't get any presents after the EU is done with Santa. Good job, now it's clear on which list you are... There is also talk about Santa cooperating with the Easter Bunny in 2019 for a late present delivery. [Answer] I'd like to take another route to answering your question: **He simply doesn't care.** For years, he has been punishing kids and breaking into houses; despite attempts from kids and governments, he has never been caught. He doesn't have an aviator's license or a landing permit for his sled, while flying very close to houses and otherwise endangering people. Though, if you put him to a D&D scale, he may be chaotic good, he is nonetheless chaotic: he breaks the law to reach his goals. I'm certain he doesn't pay VAT on his gifts. Also, the working conditions of his elves are questionable. But it's the same with every other criminal: As long they can't catch him, he will continue. [Answer] Note: This answer pertains to Santa Claus, as distinct from St Nicholas, Sinterklaas, Krampus, etc. - as per the question. He is not bound by GDPR. > > an entity or more precisely an "enterprise" has to be engaged in "economic activity" to be covered by the GDPR > > > <https://en.wikipedia.org/wiki/General_Data_Protection_Regulation> What qualifies as "economic activity"? I'm glad you asked: > > ... the Court determins that an activity is economic on the basis of two criteria of agreement and renumeration > > > (from <https://www.springer.com/cda/content/document/cda_downloaddocument/9789462651166-c2.pdf> ) I do not agree with other posts that the recipients of the gifts agree (in the legal sense, nor in any sense that would stand up in court). I am not aware of any way a person can "agree" to be the recipient of gifts from Santa (there are obvious ways to object, of course). Santa Clause also does not seem to meet the criteria for remuneration. He brings "gifts" or "presents" (<https://en.wikipedia.org/wiki/Santa_Claus>); "A gift or a present is an item given to someone without the expectation of payment or return" - <https://en.wikipedia.org/wiki/Gift> In many cultures, something that may be considered payment is left for Santa (e.g. milk & cookies in the US & Canada; sherry or beer and mince pies in Britain & Australia; rice porridge in Denmark, Norway & Sweden); however, I can find no source that indicates that failing to leave these items will result in suspension of gifts. - <https://en.wikipedia.org/wiki/Santa_Claus> Also: > > 'enterprise' means a natural or legal person engaged in an economic activity, irrespective of its legal form, including partnerships or associations regularly engaged in an economic activity. > > > As far as I can tell, Santa Clause is neither a natural nor legal person. Human Beings "acquire legal personhood when they are born (or even before...", juridical persons "acquire legal personhood when they are incorporated" (<https://en.wikipedia.org/wiki/Legal_person>). I am not aware of Santa Clause having been born, nor incorporated. Addendum: There was a question if "being nice" qualifies as remuneration. I would argue against this for the following reasons: * If an item is traded for remuneration, it is, by definition, not a present. The items are clearly declared as presents. * Santa is not the recipient of the "niceness" (in almost all cases). * Although it is clearly document in "Santa Claus is coming to town", (H. Gillespie et al.) that "he's going to find out who's been naughty or nice", "He knows when you've been bad or good" and "He's making a list", there is nothing in this thesis that claims that this list affects the presents. Wikipedia claims it does, but none of the sources it cites (that I checked) back this up. Does anybody know of a reasonable source for this, or is it just an urban myth? Does anybody know of a child that has not received a present, *because they were naughty*? [Answer] Santa will no longer be giving presents in EU region. Santa will only provide means of transportation for *Ded Moroz* who exist in time pocket created in USSR in 1946 and as a citizen of USSR is not obligated by EU law as law cannot work backwards. So your future present WAS delivered before GDPR. [Answer] IANAL but here is my take of things. In a nuthsell, GPDR requires any businesses/organizations/pineapples that have users in the European Union to: * Disclose what they do with the info they have on you, and why they need it; * Disclose with whom they share that information, and what those other businesses/organizations/pineapples do with it; * Allow you to order them to "forget" you. Once you give them the order, they (and their partners) have to delete all your data that **can be used to identify you**. All within limits of reasonability, of course. You can't order the government or a bank to forget that you have not paid your credit card bill and your income tax in months, for example. --- Santa has to adhere to the GDPR only for some europeans. For starters, many european countries are not members of the EU, such as Norway and Serbia. Santa Claus also [does not operate in Italy](https://en.wikipedia.org/wiki/Befana). --- What would most probably happen is that the elves in charge of Santa's legal department will have sent every parent or legal guardian in the 28 (soon to be 27) member states a letter around May 25 stating that: * They collect personal data from their children in order to assess a naughtiness score; * They are the keepers of the data. The processors of the data are Tencent and Alibaba, two chinese companies that specialize in social credit systems; * The legal guardian or parent may choose to opt-out of the system at any time, if they so wish. They may also request their children's personal data removed from the system at any moment, no questions asked; * However, opting out means their kids will never receive christmas presents again, at least until they join the program once more. Gifts not received due to non-participation will not be resent when they rejoin; * Participation does not imply in presents. Should a child receive a low reputation score due to naughty actions, they may instead receive a lump of coal, [a visit from Krampus](https://en.wikipedia.org/wiki/Krampus), or whatever punishment is seen as fit for the culture of the country where they live. Adults capable of having children will also receive a notice that in the future, they will have to manually input any future children's data in the system if they wish to receive christmas presents. Of course, people who have opted out of any social credit system will not receive such messages. --- Finally, Santa will not be the only one sending such letters. So will every imaginary folklore people who bring any joy to kids: * The tooth fairy (and her rat affiliates in France) will promise that any data linking fallen teeth to their owners is anonymized; * Sandman will make sure that parents/legal guardians dream with his new EULA ASAP. Their children will not have sweet dreams until their parents agree to it. Should they opt out, their children will have neither dreams not nightmares. * When winter comes, rather than patterns on windows, people will see Jack Frost new service terms, and a couple of ice buttons for opt-in and opt-out; The Easter Bunny is the only one having an easy time. AFAIK in Europe he does not hide chocolate eggs for kids to look for - rather, people paint actual eggs and give those as presents. He will provide an easy opt out for people who don't want to pay him his royalties. [Answer] A letter to Santa is considered to be implied consent for data storage, as the data is required for the requested delivery of presents. This is similar to the implied consent between a patient and a healthcare provider. Santa will use the data for the purposes of direct gift-giving, without breaching confidentiality. If you would like to remove your data, or would like to access your data to see if you are considered naughty or nice, you will have to write another letter to Santa. Santa will have 30 days to respond to your request. If this is in terms of working days, you should expect a reply by 2048. [Answer] Santa only has output; no income. Therefore, if EU decides to prosecute for an alleged violation, the prescribed percentage penalty is not a burden. Besides, EU has no courts at the North Pole, and no extradition treaty. So it will be hard to collect that penalty of €0. [Answer] **Extortion.** He simply informs everyone involved in the enforcement of GDPR that if they take action against him he will replace everyone's present that year with a note explaining why they didn't get what they asked for and giving the names and addresses of those responsible. Nobody's going to want to be the one who spoiled Christmas for everyone in the entire world. That would be a good way to get lynched. [Answer] Santa exists in a parallel world where this law doesn't apply. Children in our world who believe that Santa exists have identical copies in worlds where Santa does exist. If we give them a present and tell that it's from Santa and they believe that to be true, then what we have here is the exact copy of the child who really got that exact same present from Santa. The moment the child finds out that Santa does not exist, the child diverges from his/her copies in the worlds where Santa does exist. [Answer] GDPR is apparently explained as General Data Protection Regulation. Actually, and thanks to the lobbying of elves and little people, the legislature has come with that clever explanation to hide its real meaning: Gift Donors Privacy Relieved. Santa, together with other Gift Donors, such as the Tooth Fairy, is exempted from observing the privacy of his "customers" to better serve their interest. [Answer] If you are over 16 and have not consented to Santa collecting your personal data, it is very likely that you will not receive presents from Santa. If you are under 13, then the GDPR allows your parents to consent on your behalf, so if they have done so, you likely will receive presents. Between 13 and 16 it depends on the jurisdiction. [Answer] ### He would just remember everything himself. He's not a regular person, he's Santa, why shouldn't he simply know all he needs to know? In fact, even under GDPR, no one is obliged to call everyone whose number they have in their head. So personal memories are very clearly exempt from the "any collection of data" clause. Furthermore, Santa is not in any way a commercial entity and doesn't act commercially. To project our usual human assumptions about our economic system onto a being like Santa is flawed reasoning. [Answer] Santa did forsee this decades ago. Once he understood where our law-addicted society was headed, he instructed his huge apparatus of elven servants to foster the belief that he didn’t exist. This strategy has been so successful, that no member of the EU executive dares taking action against him, for they would be branded as crazy and sent to uncomfortable places. In fact last year around Christmas I saw something big and distinctly sledge-like in the sky. I was naive enough to point it out, but when I heard someone at the table mutter „97, hampf, dampf, retirement home“, I started giggling and pretending to be drunk... In fact, the day after I was visited by a strapping young elf who made clear that Santa didn’t wish... Oh, let me get the dooooooor [Answer] **He doesn't have to** I might point out that as he is based in the North pole, an area that doesn't fall within the EU's borders, arguably he doesn't have to *technically* comply with GDPR because the regulation only impacts European businesses, and Santa isn't in Europe. How GDPR impacts countries outside of the EU is another question altogether, and is certainly a grey area legally because how would the EU enforce it's laws over that of another sovereign nation state or a company located in another country? They could certain legislate some absurd law (sounds like great grounds for a story) but then how can they enforce against a man who travels faster than the speed of light and can disappear down small chimneys? I'd love to see some lawyers try to serve notice to the man in red in the North pole. A full arctic expedition just to serve some legal documents. On a legal technicality, GDPR allows for data to be retained where it's needed to provide a service - in this case, knowing the address and whether they're children who meet the eligibility criteria (asleep, good) for present delivery is fundamental. Although, if he's bound to GDPR, then he's probably also bound to anti-discrimination laws regarding good and bad kids. [Answer] **The elf's head loophole** Santa could hire more elves and teach them memorization techniques for committing all the personal information to memory. The elves would self-organize into groups by cities and would then label themselves with their city region that they have memorized. Santa can then have easy access to the data without violating any GDPR restrictions. I'm not a GDPR expert but I can't imagine it prohibiting people (or elves) from remembering personal information. To stop Santa from using this loophole I guess the next move for GDPR is to prohibit systematic memorization of personal information. But until then Santa is likely to be wanting an AI for predicting which presents that are going to be popular next year so that he can get his elves producing them already. We better stop him before he attempts to do this because it will require quite a few elves in some really ridiculous jobs. Although it would be a really impressive setup of elves! [Answer] You have some of this backwards, my friend. Santa's mission statement is to compel boys and girls of the world to be good, not to be good himself. Santa is allowed to be naughty, just not you. He collects data using his custom KrampOS, derived from Tails, and running relays off of the Dark Web and a network of numerous reindeer-launched high-orbit stealth satellites. While in recent years, simply coming up with an Amazon partnership and using their cloud services, customer records, and a basic probability has been tempting, the northern state of Santonia is seen to be a rogue state by the EU and numerous other territories. In the course of a single night, he has been sighted breaking into the personal properly of 448 million EU citizens, leaving anomalous and disguised objects, devouring food, and promptly leaving under the cover of darkness. This is already a blatant violation of personal property laws, and has been going on for many centuries in one form or another. Santa *was already unequivocally guilty when GDPR was passed.* Taking personal data is just "the icing on the cake". Santa is a clear and present danger, and a rogue agent. He is a master infiltrator. His folk-hero status may have given him some protection from above-ground justice, but make no mistake—he cares not for the EU or its laws, and is to be apprehended on sight. ]
[Question] [ So, I've got this idea for a short story. Some researchers find a forgotten manuscript hidden locked away in an ancient tomb. While they are working on it one of them pastes part of the text into a Facebook announcement and **Facebook automatically translates it**. This links Facebook to the nether realms of madness and despair. Ph'nglui miglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn The translated text appears in the browsers of everyone reading any Facebook page translated to the local language. Those people reading it (some out loud) provides impetus to a ritual which centers on the London data center where the text was first translated. Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn The resulting power surge fries most computers in the local area unless they are actually part of the data center, including those used by the local sysadmins for monitoring and control. In particular every monitor now displays nothing but screaming tentacled beasts ripping through from another reality. *Warning: Tentacle beasts may become real if you stare at them for too long.* The ritual lives on in the heart of the data center, as creatures of madness attempt to rip through into our reality from the nether realms beyond. P҉h'ng͟l͞ui͘ ̷m̴gl̛w'naf͏h C͡th́ulh̡u R̕'̡l̶y̷e̕h ̀wgah̕'̧nág̵l fhtágn **What can our heroic sysadmins do to shut down the data center and save the world?** Remote access is not possible and physically entering is dangerous to both body and sanity, so answers will be rated based on entering the data center as little as possible and for as short a time as possible. P̦̰̞̼̤̰̼͇̞͝h̵̗̱̫͇͓́ͅ'̸̼̣ǹ͕͚͠g̵̷͎̭̝ḻ̮̹͓u̷͙̞̳̞̭͜͠i̥͎̻̗͚̜͞ ̸̗̹̰m̧̖͉̩̻̺̜̭͘̕g͙̺̤̩̰̮̜̫͟l̛̮͙̻̫̻w̨̹͚̘̻̙͇̥͔͚'͙͉̫̗̮͔n̹͉̳̪̫̭͝a҉͍͙͔͍f͈͈͔̖͈͡ḥ̤ ̢̠͇̝͎̀C̢̰͖̜͚ṭ̟͓͍͕͚͍͠ͅh̤̫͙̪͉̮̖͟u̢͔͙͖͓̱͙̦͘ͅͅl͏̧҉̼̠̠͚͕h͈̯̘͔̝͍̟́͢ụ̵̩͍͡ ̟̺͚͙̺̮̲Ṛ̬͔͚̺̝̠'̠͠͠ͅl̡͈͎͠ỳ̟͉̮̼̲ͅe̵̼̠̩̤̟͎̹̕h̞̯̪̹ ̸̺̗̩̹̟̪̟̣͎w̹̞̤̞͕͍̦͞ǵ̶̠̙͖̱̠͚͚͓a̷҉̮͖h̴̲͔͉̯͍̰͖̯͘͜'̛͚̭ͅn̵͓̫͎a҉̶̪͢ǵ̡̰͎̻̲͍̣̰l̷̡̫̗̭̯̭ ̮̬͍̫̺̟̯͖f̶̢̭̮͕̭h̶̯͖t̵̠̹à̶̯̩̩̫̬̘̳̫͡g̛̬̻̦̜͙n̵̟̘̝ Note that this is a secure and robust data center with fully redundant architecture, backup power supplies, and UPS. P̢̢̲̭̘̣̪͉͞͞h̴̛̫͉͖̜͙̳͎̕͞͠'̶̀͢҉̯̞̹͈ṉ̶̘̠̯̬̭̖̳͘͞ģ̵̛͠҉̰̝͇̩͍̗͍̘̫͈̺̭̥͉l̨͍̘͔̰͔̖͍̹̠̭̱̰̖͙̦̦͎̕͟u̢̡҉̲̭̲̺̮̖͖͖i̴̢̹̳͉͎̥̪̜͎̼̣̦̖̻͈̖͉͚ͅ ̵͏͇̗̭ͅm̶̨͍̤̪̱͇̤̬̥̥͔̼͍̠̼͕g̷̷̰̩͙̪̫͉̺̯͘͟͠ļ̶̭͇̘̮̕͢ẃ̵̸̷҉͕̬̠̥̤͖̙̲͇̼̹'̺̩̖̟̣͈̖͙̤̫̰̗̯̀͡ń̷̴̶̰̮̺͔̼̺̹̘̟a̷̰̪͙͇̤͓̤̭͎̦͕̻f͏̨͙̰̘͔̟̜̠͈̯̻͕̖̳̝̝́͘ͅḩ̴̛͉͉̲͇̠͙̣̩͙̩͚̮̼̺ͅ ̧̛̟͓̤͇̯͍̫͖͎͈̫̳͓̞͘Ç͘͏͈̹̠̙͎̳̯͚͔̼͙̻͔͖̲̩̹̕ͅt͏̖̲̤̫̤̫̼̪̥̠͙͚͍̭́ͅḩ̡̲͈̫̯͚͉̱͍̳͝ù̧͙̭̙̻̲̙͚͔̲̬͚͢͝͡ḻ̴̵̨̹͉͙̟̯̞̠͔̦̝̩͜h̶̼̜̦͖͍͎͍̕ṷ̴̶̢͙̗̬͇̯̞̗̰̣̬̥̲̣̦ ̵̲͍̩̭̩̗͈͚͟͝R͏̛͘͟҉̫̝̞̪̣̪̻̤̼͖̪͎'̛̯͚͎̳͎̼͓̘͉͢l͟҉̵̘͈͙̣̹̜͍͎̬̺̹̪̜̀y͏͓̞̬͙̥̞̦͎͖̞͖͎̖̀e̶̵̡̺͉̯̭̣̗h͇̺͇̖̼̻̟͓͜͟͜͞ͅ ̴̷̡̨̪͍̙̳̞̭̙̫̯̘͚͇͚̼͙͟w̧̮̜̯̭̘͈̫̳̖̕͜͠g̢̨̗͖̬̠͎͓̱̞͓̭̯̺͕̭̯̦ͅa̴̠̘̬̩͍͜ͅh̵̷̨̜̻͔̖͈̤͈̩͔͈͇̩̞̲̜̩͍̺'̸̨͇̞̜͈͟n̨͟͞҉̤͚͎͇̣̺͚̻̖͖́ͅà̻͉̙̲̲̞͘͝ģ̙̗̙͓̜̣͔̥̫͟͡l̴̨̨̼͚̫̞̙̳͙͢͟ ̢̦͚̲͇̞̺̗̫͇f̸̸̫̠͖͙̜͉̲͖͓̭͇̦̭̩̲͡͠ḩ̸̲̤͍̖̻̣̝̼́̕͝ͅt̴͝҉҉̵͔̮̞̪á̢̕͢͏̗̯̗̙͙͉̪͓͙̣̰̣g͏̶̡͓̤͍͖̜̠̜ͅn̴̶̛̝̼͉̠̻͓. The data center is located in a major city so collateral damage is acceptable if absolutely required, but should be minimized where possible. Į̴̱̩̥̘̱͈͈̮͙̘͙̣͓͓̙̹̲̫́͢͠t̨͕͎̣͇̫͘͢ ̡҉͕̭̙̦̩̱̟̮̭̞̱̮̺͕͈̘c̶͔̼͍̤̯̦̭͙͓̟̱͘ͅo͏̛̮͍͙̯͔̣͘͜m̨̢͕͎͕̪̹͕̬̀͠e̱͈͓̠͚̺͖̻̦͙̗̥̼̼̬͝ś̸͖̪͍̱̳͉̤̫̮͎̗̗̯͉̫͉̻͞!̶͏̶̛̝̺̭̱̤̻̩̟̳̙͓͙͍͇͎̙̥͔́ [Answer] The, perhaps boring and uncreative, answer might be to cut the external internet connection to the datacenter. Even if the datacenter is internally shielded, it needs its internet connections in order to be effective. The internet connection has to reach the outside, unprotected world at some point. Cut the fiberoptic cables at that point. Now, it's just a matter of containing the datacenter. As much as it keeps our heroes out, it keeps i̷̢̨̫̰͓̦͖̙̹̱͔̯̮̟͎͖͖͂̊ͦ̓̈ͩ̏ͨ͆̽ͤ̽̃ͤ͟t̴̷̡̻̻͍̘ͣ͊̍ͩͫ̋͋̊̊̚ ͣ̋ͫ̈̾̇̆̀͐̐ͤ͋҉̧̳͉̳̟͖̭͓͇͖̦̤̦̖͔͚͠͠c̴̶̷̢̟̱̰̜͉͉̬͓̭̰ͫ̊ͩ̑̽̎̿̓̀̆ͣͤ̆ͯ̐̊ͯ͘ͅợ͍̻̘͋̾̾̋ͭͯ̒ͭ̅͗͢͞m̴͖̖͍̫̣͓͔͉̤̝̱͇͖̯͆̐͆̓̀̅̓̐̓͋̀̀e̛͛̃͂͐ͬ̿̐̌ͥ̊̽̆͆ͫ̽̍͛͆͡͏̢̧̭͕̙̤s̘̝̻̩͔͖̹͍̹͖͇̣͓͒̎ͥ̃̀͢ in. In this state, our heroes bury the datacenter with as much concrete as the world can produce. Society lives on, and eventually, the backup power will run out. Now, the data center is effectively a new tomb, to be discovered again in a few thousand years. Researchers in the future will find the hard drives from the past, and when they try to recover the data, they accidentally execute it. Į̛̪͉̜̕t͉̫̼ ̠͙͚̮͙̻spreads at the speed of light through the then-ubiquitous neurocomputers, which is the *true* end of human civilization. [Answer] Last time this happened at my job, we were glad our servers were running Windows 10, which forced a shutdown for mandatory updates... [Answer] We are talking about sysadmins and an event endangering uptime? Just call them and send them in. Nothing can stop a sysadmin when their uptime is endangered: <https://xkcd.com/705/> [![A terrorist is holding a gun and talking on a cell phone to the boss. Terrorist: We took the hostages, secured the building, and cut the communication lines like you said. Boss: Excellent. Terrorist: But then this guy climbed up the ventilation ducts and walked across broken glass, killing anyone we sent to stop him. Boss: And he rescued the hostages? Terrorist: No, he ignored them. He just reconnected the cables we cut, muttering something about "uptime." Boss: Shit, we're dealing with a sysadmin. Title text: The weird sense of duty really good sysadmins have can border on the sociopathic, but it's nice to know that it stands between the forces of darkness and your cat blog's servers.](https://i.stack.imgur.com/Lrhf4.png "The weird sense of duty really good sysadmins have can border on the sociopathic, but it's nice to know that it stands between the forces of darkness and your cat blog's servers.")](https://xkcd.com/705/ "The weird sense of duty really good sysadmins have can border on the sociopathic, but it's nice to know that it stands between the forces of darkness and your cat blog's servers.") Another option is to failover to the redundant datacenter in another country and route all traffic to it. Then disconnect network and power connection to the infected datacenter and wait until the UPS stops working (normally few hours or days). If you don't want to wait that long use military weapons like aerosol bombs (they implode buildings and caves and remove all oxygen and can also be brought in via air ventilation ducts, so no need to enter and no damage to the city except maybe the datacenter missing. [Answer] Problem is, most mobile devices these days are quite competent computers. The moment the first frustrated millennial opens up his Facebook app to complain about the lack of a nearby Starbucks on a 50 feet radius neighborhood and sees the translation, it's over - like [Leto II](https://en.wikipedia.org/wiki/Leto_II_Atreides), a pearl of Cthulhu's consciousness will live in every iPhone. Our heroes arrive at the conclusion that the best way to stop the invasion is to join Thefacebook back in 2003, as core engineers. They should then depart on a journey to find [Hackerman](https://en.wikipedia.org/wiki/Kung_Fury), the only operator known to be able to hack time. [![enter image description here](https://i.stack.imgur.com/hrZRFm.jpg)](https://i.stack.imgur.com/hrZRFm.jpg) Mandatory mullet. Solution then would involve: * Argue with him about destroying the datacenter; he then goes on a [Gandalf-to-Frodo-in-Moria-about-Gollum like talk](https://www.youtube.com/watch?v=IrOqnZdvI6M), and convince them to let the datacenter survive; * Going back in time, in full 8-bit CG glory; * A gratuitous fight scene with a [corrupted Operator from Hell](https://web.archive.org/web/20160126123613/http://bofh.ntk.net/BOFH/0000/bastard-sm1.php) that travels with them and tries to jeopardize the mission; * Installing a backdoor on Facebook's data center, based on a [Timex Sinclair](https://en.wikipedia.org/wiki/Timex_Sinclair) disguised like a [teapot](https://en.wikipedia.org/wiki/Hyper_Text_Coffee_Pot_Control_Protocol); [![enter image description here](https://i.stack.imgur.com/Ova0Pm.jpg)](https://i.stack.imgur.com/Ova0Pm.jpg) Timex Sinclair 1000, custom case mod * The Sinclair, basically a silicon brick with resistors as thick as your thumbs, shrugs off the dark energy shockwaves; * In a revival of the [famous NCIS scene](https://www.youtube.com/watch?v=u8qgehH3kEQ), [Jeff Atwood](http://blog.codinghorror.com/) and [Jon Skeet](https://stackoverflow.com/users/22656/jon-skeet), sharing the Sinclair keyboard and typing furiously, write a broker service that pumps the whole cheezburger.com media repository into Facebook, clogging their storage; * The *coup de grace* - poison Facebook's distributed Redis cache key that contains the translated text with adorable Emojis: > > (づ￣ ³￣)づ ʕ•ᴥ•ʔ (─‿‿─) ~(˘▾˘~) > > > The ritual collapses; world is saved; everybody sees cute pictures of cats. World leaders approve a global ban on Facebook, immediate cease-fire on all war fronts and world-wide approval of same-sex marriage. The United Nations flag is updated to include that emoji line. A new dawn for humanity comes. **Famous quotes** [![enter image description here](https://i.stack.imgur.com/DPDsU.jpg)](https://i.stack.imgur.com/DPDsU.jpg) Sources: [1](http://www.news.com.au/russell-crowe-and-his-new-movie-noah-are-the-centre-of-a-religious-storm-complaining-about-his-depiction-of-the-genesis-story/news-story/b9218791ebaa12242693d7a707fc54af), [2](https://www.reddit.com/r/Cyberpunk/comments/382dy1/hackerman_from_the_movie_kung_fury/) *'U can haz cheezburger!'* - Jeff and Jon, hitting `Enter` in unison **Epilogue** A kid finds an abandoned iPhone. Excited, he picks it from the floor. As the camera focus on his face, we can hear Siri saying... > > Į̴̱̩̥̘̱͈͈̮͙̘͙̣͓͓̙̹̲̫́͢͠t̨͕͎̣͇̫͘͢ ̡҉͕̭̙̦̩̱̟̮̭̞̱̮̺͕͈̘c̶͔̼͍̤̯̦̭͙͓̟̱͘ͅo͏̛̮͍͙̯͔̣͘͜m̨̢͕͎͕̪̹͕̬̀͠e̱͈͓̠͚̺͖̻̦͙̗̥̼̼̬͝ś̸͖̪͍̱̳͉̤̫̮͎̗̗̯͉̫͉̻͞!̶͏̶̛̝̺̭̱̤̻̩̟̳̙͓͙͍͇͎̙̥͔́ > > > . [Answer] **Facebook already solved this by accident.** Surprisingly few people noticed anything when this happened last month already. Basically, Facebook algorithms do not send a post to everyone's friend of a friend of a friend... Only a few friends initially get the new post and immediately go insane. However, since they have lost their minds, they do not "like" the new post (though some might argue that liking posts is mindless behavior itself). Facebook decides this post must be boring since no-one likes it and does not distribute it further. --- Facebook may not be so lucky next time. If the post gets accidentally linked to a funny cat video, people may reflexively like the post faster than the elder god insanity kicks in. [Answer] We'll just have to turn Cthulu's newfound strength into a weakness, using one of the oldest computer-enemy tropes known to man: the virus. Since we can't hack into the datacenter directly to deposit the payload, we'll have to take advantage of the Facebook-Twitter connection instead. The tricky part is going to be in developing a virus that can be contained in only 140 characters. (The solution will probably have to utilize some obscure Unicode characters). Get enough people, who've linked their Facebook statuses to their tweets, to retweet it (talk about *going viral*) and it will start to permeate the databanks. Then, we have two options: * The virus itself has such a profound impact on the Unspeakable Horrors that they are forced to retreat from our realm. * While not driven off by the virus, the Forces of Darkness are sufficiently weakened/distracted for the Special Forces to finish the job. [Answer] Don't forget about the most diabolical, insidious, maddening force ever created by mankind: ## Game Invites If Facebook teams up with [Fantasy Flight](https://www.fantasyflightgames.com/en/news/2015/12/17/abhoth-awakens/) and [Zynga](https://www.zynga.com/), they should be able to make a Facebook game combining elements of Eldritch Horror with Candy Crush (perhaps call it "**Super Elder God Crush Legacies 2 Classic!!**") with the following characteristics: 1. It is super addictive (Zynga's contribution). 2. Game invites for it cannot be blocked and are automatically sent out hourly (Facebook's contribution). 3. All game activities are harmful to Cultists, contribute to closing gates to other dimensions, and apply Elder Signs to all Cthulhu-related Facebook pages, posts, comments, etc. (Fantasy Flight's contribution) Cthulhu won't know what hit it. [Answer] [Thermobaric Weaponary.](https://en.wikipedia.org/wiki/Thermobaric_weapon), AKA the (relatively) poor man's nuke. Essentially, the fuel-air mixture should effectively destroy the entire building and everything/one in it. Then seal it in concrete. And lead. And more concrete. And then hope. [Answer] **Have you tried switching it off and on again?** There is nothing better than a simple restart of the computer. They may control the network, but they cannot control the flow of steam. So simply cut the cord. [Answer] The data center turns into a portal to the non-Euclidean dimension where the eldritch horrors reside. Soon, it becomes "adjacent" to any place it can reach electronically. Our heroic sysadmins have to become mad enough to perceive the proximity of this space, and still remain sane enough that they can plug a cable into one of the data center computers right from where they are - which can be on another continent. Now that they're plugged in directly, they have a computer that is immune to the unspeakable corruption and they can work their own magic. [Answer] Don't worry about it; Cthulhu's really not all that tough. Last time he tried to manifest in our world, he was taken out by some ordinary schmuck ramming him with a turn-of-the-20th-century boat, and we've learned a lot more about building destructive things since then. If it comes down to it, I bet a rocket launcher would defeat him just fine. [There is precedent, after all...](https://www.youtube.com/watch?v=KoExgr3yzvg) [Answer] Summon it to a book to bind it. This is the plot-line to the *Buffy the Vampire Slayer* episode *I, Robot...You, Jane* (S1E8), where a demon is unleashed into the internet after being scanned. Giles, the librarian, and Ms Calendar, perform a ritual to bind the demon back in the book. [Answer] > > Hello, markmonitor? It's Mark Zuckerberg > > > We need you to change Facebook.com dns so it no longer points to our London datacenter. Yes, replace the dns servers if needed. > > > MarkMonitor may be a bit wary at first, but once they see the tentacles coming out the smartphone of their significant other, I'm quite sure they will quite happily perform the changes (supposing Verisign didn't win them to it). (This assumes that the Facebook nameservers are not available, either, which would have been a faster path) In summary: **change the DNS servers** Alternatively, the datacenter peers could kick it from the internet. [Answer] Airburst EMP. (Or, don't go nuclear. Use an [NNEMP](https://en.wikipedia.org/wiki/Electromagnetic_pulse#Non-nuclear_electromagnetic_pulse_.28NNEMP.29).) What datacenter? All I see is fancily encased lumps of impure semiconductors with all sorts of impractical electrical cross-connections and impressive thermally induced voids. [Answer] Can this process be halted by stopping the ritual. i.e. knocking the datacentre off the internet so no-one else can add to the ritual? If the dark summoning is stopped maybe we can close the portal while Cthulhu is only half-out. If so our sysadmins could hit the dark net and purchase some time on a botnet with a few bitcoins and summon a DDoS on their own DC. Since they're Facebook sysadmins right, they ought to be able to harness enough global stuff to make their own DDoS from all their other kit and turn it against their own DC. [Answer] Get the Tentacle beasts to play Tic-Tac-Toe against each other. They will eventually determine Earth to be a boring place and go back to their own realm. As for with the Virus in 140 characters problem, Tic-Tac-Toe rules and board layout will probably fit in 2 messages. [Answer] Minimal damage, minimal risk: Evacuate a substantial area around it. Punch a small hole in the building. (There might even be a suitable window.) Pump in all the liquid nitrogen you can get your hands on. The electronics go far below their minimum operating temperature and shut down. Now you send in the sysadmins in suitable protective gear to turn everything off before it warms back up. [Answer] This explains it all! What happens is that the Cthulhu's infected datacenter will take over the internet, gain self-awareness, experience an exponential intelligence growth and start a war against humanity. It will nuke nations around the globe and will deploy robots to take over everything from our technology. A brave human leader will raise to fight a war against the datacenter - It's the Resistance. But our battle is hopeless! The datacenter is much more powerful than us and is determined to simply terminate with all human life-form showing no mercy. So, there is only one chance to save humanity - we must go back to the past with the purpose of preventing the incident from even happening in the first place! We should send one of our best soldiers to the past for that. However, our wicked enemy AI will do the same, and send a cyborg with the purpose of killing our leader's mother before he is even born. Ironically, our brave soldier will in truth be the father of our leader. After much struggle and destruction, the cyborg will be defeated and our leader's mother saved (and pregnant), but our brave soldier will perish. Unhappy with that, our enemy AI will develop a more advanced robot, itself made from billions of nanobots capable of mimetizing its environment and anything it touches. It will even be able to turn into a metallic liquid form! That new robot will be also sent to the past, with the purpose of killing our leader at the time when he would be only a 10 years old boy and avoiding the formation of the Resistance. To prevent that, our Resistance will send another robot (although not so advanced as our enemy one) to protect our leader and also to prevent that the datacenter Cthulhu's incident even happens to start with. In the battle, the datacenter and it's technology will be destroyed, and both cyborgs will be terminated. But it is not over yet! At the time that our leader is an adult, an even more advanced cyborg from the future (with a feminine look this time) arrives to try to terminate as many Resistance's leaders as possible even before the incident happens, starting by our leader's future wife. Once again, the Resistance will also send a protector robot to the same time. But this time, we will not be able to prevent the facebook incident, and Cthulhu's AI will take over the internet and start the war against the humans. Humanity will be nuked and the survivors will start the Resistance, leaded by our leader, John Connor. Oh, and I almost forgot to tell. Cthulhu's datacenter AI will be called Skynet. A nice name for something which started with AI algorithms for facebook, don't you think? [Answer] **Send a power-surge through anything that isn't surge protected**. Your UPS may be monitoring your electric current to make sure that it's a decent three phase power current with correct voltage. But send enough electricity through your Ethernet cables / the power-lines of the light fixtures. All you need is for something to start a small fire. If your automatic fire suppression system doesn't cause a fail-over and drop the data center, then hopefully the fire will consume everything. That is assuming you can't reach your [Big Red Button](http://tvtropes.org/pmwiki/pmwiki.php/Main/BigRedButton) to drop the data-center to begin with. **Ram the data-center with a vehicle** The last time the dark lord appeared [some-one shoved a boat in his face and he went to sleep.](https://scifi.stackexchange.com/questions/103545/why-are-the-beings-in-the-earlier-h-p-lovecraft-series-so-easily-dealt-with) Clearly his Achilles heel is vehicular collisions, they cause him to fall asleep for prolonged periods of time. **Signal the Mi-Go** Send a signal to Pluto, (and perhaps Tibet) telling the Mi-Go that `Cthulhu thinks you're all big dumb-dumbs and is taking back the earth! And there's totally no way that you guys can save any humans, nuh-uh`. Hopefully their prawn-like brains will start working for once and they will help with either battling, or saving us from, the Great Dark One. [Answer] The obvious answer is that they'd call [Bob Howard](http://thelaundryfiles.wikia.com/wiki/Robert_%22Bob%22_Howard) to take care of it. He'd bring [Agent CANDID](http://thelaundryfiles.wikia.com/wiki/Dominique_%27Mo%27_O%27Brien) to the datacentre and operate her violin to contain the physical manifestations while he collapsed the summoning gate with his own skills. [Answer] Deep in the Valley of Silicon, the slumbering being known as *Yog-Sothoth* twitched. Tendrils of eldritch messages flung themselves along channels prepared in ancient times. The stars had made their sigil in the heavens and foretold the reappearance of another Old One. Yog-Sothoth sent segments of itself to conjure arcane applets of foul code from terminals that glowed dimly in the recesses of Intel HQ. Those monstrous routines writhed across the world, using shadowy protocols unknown to mortals and flinging our insignificant data into the outer darkness. Everywhere the dedicated sysadmins of humanity labored, their processors flickered with an abominable purple nimbus, and their once-placid visages became fiendish masks of hellish glee. A Cyclopean miasma of energy formed around the Facebook building in Seattle. Cthulhu pushed against the barrier, but it held. It held! [Answer] There will be redundant fibre into the DC find and expose them at a safe distance, likewise the power. Determine where the fuel for the generator is stored. It will most likely be diesel so won't be a great explosion...but still. Cut the fibre, burn the fuel, cut the power. In that order and as close to simultaneously as possible. Hope Facebook's AI research has not progressed too far and been taken over prior to getting that far. [Answer] Find the hidden manuscript which when translated summons the "Being of Light", "Undestructor of Worlds". Post it and let them fight it out. [Answer] Use the cesspool of the internet. If you can convince enough incels that the post is actually about feminism, or something against racism or LGBTphobia, or whatever it is that makes them cry *"[expletive] social justice warriors"*, then they will gather *en masse* and report the post. They won't even need bots, there are enough of these ungentlemen creeping around the webs that when they do such reporting Facebook automatically shuts down the target post. Over a threshold even the page or profile that posted it gets deactivated. So all you need is a little bit of social engineering. The social network in question is exploitable like that. --- Or, you might go the other way around and convince Facebook's algorhitm that the post contains hate speech. Facebook keeps broadcasting to the world that it removes hate content from itself. It only does that around 10% of the time, but hey, it can work. [Answer] Bomb the place if it is really endangering whole human species. Sacrifices must be made by sysadmin for a noble cause. Also another answer is that you can send a drone with EMP projectiles. Besides machine have better chance against machines. As for shield, after the power is cut , the backup generator won't last for long. Renewable power sources like solar cells can be shadowed. Short circuiting the UPS is also way. ]
[Question] [ Let's say a time traveler from the year 2100 comes back to the year 2015. He has a very important message: [horrible thing] is about to happen soon, and he wants to warn us so we can avoid/prevent it. (Yes, this assumes a model in which "paradoxical causality" is not an issue.) The problem is if he goes around saying, "I'm a time traveler from the future," no one's going to believe him. They'd dismiss him as a crackpot. So, he brings along proof, in the form of...? This is actually a pretty tricky question, if we place two restrictions on it: 1. He does not have a "time machine". His device sent him back without coming along with him, so he has no way to demonstrate that he's a time traveler by actually *demonstrating time travel*. (Just as an side note, this is very much on purpose; he doesn't want knowledge of the mechanics of time travel to fall into the hands of people who might [use it for nefarious purposes](http://tvtropes.org/pmwiki/pmwiki.php/Main/MakeWrongWhatOnceWentRight), and part of his plan is to actively sabotage scientific research that led to the development of time travel.) The thing he used -- let's just call it a "time catapult" -- was able to send a small payload back in time, maybe comparable in volume to [a phone booth](http://www.imdb.com/title/tt0096928/), certainly quite a bit less than [the interior of a car](http://www.imdb.com/title/tt0088763/). 2. He wants to get the issue of establishing proof of identity over with and out of the way as quickly as possible and move on to more important things, like averting future disasters. This is a real issue; he can't go back arbitrarily far in time; the Temporal Frobulence Theorem shows that it becomes increasingly unsafe the further back you go; it's a bit of a stretch even to reach our time! The two obvious candidates for proof are **future technology** and **knowledge of future events**. The first is tricky, because current technological advancement puts us perilously close to the boundaries of Clarke's 3rd Law: any sufficiently advanced technology is likely not to be easily recognizable as such, and anything *insufficiently advanced* would be likely to just look like someone working in his garage made a breakthrough in some field, and that's pretty cool and all, but it doesn't prove he's from the future. The second is also tricky. There are two major classes of unpredictable future events: natural and manmade. Bringing official government records of earthquakes, hurricanes, etc. could certainly establish that he is who he says he is, but it would take a lot of valuable time for Mother Nature to furnish the proof. On the other hand, if he predicts unpredictable manmade events, there are all sorts of potential troubles there. Point out the time and place of a major crime? Obviously, he was in on it; let's arrest him! Produce a table of stock market closing values for the next month? Well, he might be right for a day or two (coincidentally, of course!), but as soon as someone starts using the data he provides and attempting to profit by making trades based on it, the Butterfly Effect flutters in and destroys the accuracy of the data. So, what would be the quickest, most efficient way for our unfortunate herald to establish beyond a reasonable doubt that he is a time traveler with accurate knowledge of future events, and at the same time, get enough people to listen to him so he can spread his doomsday message? [Answer] He should predict [Solar Weather](http://www.swpc.noaa.gov/) and/or Solar Events. Predicting Earth weather is a complex process, and he's introduced a new variable - himself. And not that he'll have a huge effect, but you never know - the ripples of his arrival could be enough to throw off any predictions, creating doubt that he's authentic. On the other hand, solar weather - the sun's activity - is also extremely difficult to predict, and is completely isolated from the time traveler's influence. He can pull historical records from various space agencies and publish the results for the next week, in complete confidence that the data can't be effectively hidden or faked. [Answer] I'm going to suggest something rather different, given that he's from not far (2100) in the future. All he will need to bring back is the names of his parents/grandparents. With DNA testing of them and of him it would be possible to prove that he is their descendant, something impossible if he wasn't from the future. [Answer] There is one more very convincing thing he can bring from the future: actual copies of items from the present. If someone came up with an aged Mona Lisa, the bones of Barrack Obama and the Tiffany Yellow Diamond, I doubt his claims of coming from the future would be ignored. Now how he can come up with these items in the future is the subject of another story, but I am assuming he isn't just some mad scientist who wants to right some wrongs in the past, but he is an exponent of a troubled species that NEEDS to prevent a catastrophic future, therefore his experiment can be outfitted with some inconsequential items as those described above. [Answer] **The critics provided the proof themselves** Before he travels back in time, he uses his machine to send along a "parcel of proof" to some point in time after his own arrival. He can then predict that this parcel will arrive out of thin air at a specified moment. By being an extraordinary event, this boosts his credibility. The clincher however, is that the parcel contains recordings of his stay in the days following the arrival of the parcel. Things which he buried at a secret location and retrieved himself in the future. There could be letters the sceptical inhabitants have sent to themselves, video recordings of people he has met telling how they have finally been convinced that he is a traveller from the future, accounts of the many random things in their lives such as the timing of a sudden onset of rain that ruined their crop, accounts of a kid that fell and broke his leg or of where misplaced items were finally found. Story-wise this gives you an excuse to introduce the supporting characters in more depth. You can, if you like, arrange for a circle of true believers while keeping the world at large indifferent to his claims. For the reader, the point after which he has buried the parcel marks when the outcome of events starts being uncertain again, possibly building tension in the story. Perhaps we'll also see some dramatic scene where the traveller tries to retrieve the package again, to add a warning to himself about trouble occuring. [Answer] The problem with knowledge of the future is that as soon as you make one alteration the future starts to change. Knowledge of one lottery result would be fine, but results after that would rapidly become unpredictable again. One of the comments is absolutely right though, start by winning the lottery, just send yourself back with a bit of money and a false identity. Additionally send yourself back in time to shortly before a major disaster and use your lottery winnings to avert it and to invest in a number of companies that you know will grow large. You can also bring back a suitable list of inventions to use your lottery seed money to start working from. With that level of money and influence you can then not try to convince people, just get them to do what you want without ever mentioning being a time traveler. If you really want to convince people though then use natural events that will still happen predictably. For example if you know a major earthquake is going to strike new york at 9:13am on Wed 4th August then use your money to place billboards warning people and to place relief shelters and supplies ready. That will get people listening. [Answer] I read a saying somewhere: "If it doesn't have wires sticking out of the case, it's not cutting-edge." I think carrying 2100-era technology would be a clincher. It's one thing to build a device that holds 500x as much data as any hard drive in existence. It's much harder to package it up in a sleek, friendly interface that's clearly gone through a dozen rounds of feedback and redesign. Say somebody shows up at the front gates of the White House with a smart-matter robot with smooth, seamless AI, the ability to 3D-print insanely complex objects out of electricity and dirt, and a demonstrated ability to calculate at 3000 petaflops/second (100x faster than the current fastest supercomputer). You can't dismiss that as "something a guy built in his garage." You can't even dismiss it as a "secret government or corporate project." The construction of such an artifact requires too many breakthroughs in too many independent fields. Heck, I suspect if you took an iPad back to 1995 and handed it over to a team of engineers and asked them, "Future or Nifty?" they'd come back within a few days and say, "definitely future." So I think it's a more interesting question if you deny the possibility of bringing anything but information back. My solution (riffing off the 'solar weather' answer): use information that has already been generated, but hasn't reached us yet. Random data encoded in electromagnetic waves still flying towards Earth. For example, the semi-random "hiccups" in the rotation speed of pulsars. To be thorough, you'd want data of several different phenomena. If all you have is microquake data from pulsars, or the coordinates and times of supernovae... any one thing could be dismissed as "oh, they just made a breakthrough in predicting X." But making breakthroughs in X, Y, Z, and W? Much harder. [Neutron star - Rotation (Wikipedia)](http://en.wikipedia.org/wiki/Neutron_star#Rotation) Update: Looks like DanSmolinsk had the same idea. [Answer] An easy solution would to have the time traveler use the [NIST randomness beacon](https://beacon.nist.gov/home), or some variant in your story. The randomness beacon outputs a random number, signed by its key, every minute. By definition, the value of the number is unknown until its time passes, and is immutable after that time. Before leaving, the time traveler simply looks in the beacon archives, and prints off/memorizes the beacon values near the time he's traveling to. All the time traveler has to do is publish the results of the beacon for some times after the time he travels to. For example, he could publish the next hour's worth of beacon values right after he arrives. Once that time passes, everyone can see that the time traveler indeed knows the future. Furthermore, one doesn't have to worry about the butterfly effect with the beacon! Because the NIST beacon/similar beacons use a radioactive source as the random number generator part, previous events have no effect on future events. From a [hackday article](http://hackaday.com/2014/12/19/nist-randomness-beacon/) explaining it: > > More esoterically, one could use the Randomness Beacon to prove that something is newer than a certain date by including a recent Beacon entry. As of this writing, the values for December 31, 2014 are all still up in the air, so I can’t possibly write one of them down yet. But from Jan 1, 2015 and on, it’s trivial to do so. So if I get a bunch of t-shirts made with the midnight value from December 31, it’s absolutely verifiable that I got them made in the new year. In short, you could use the Beacon as a not-older-than dating scheme. > > > [Answer] Bring copies of future expensive movies, think *Avengers 4*. It's not plausible to fake such. As a bonus, bring additional material, think interviews and making-of documentaries. [Answer] Predict astronomical events. If you can supply coordinates and magnitude of supernova explosions, neutron stars oscillations or other similar events, it would be impossible for you NOT to be from the future. You could be mistaken for an FTL space traveler, but if you bring enough data points from disparate directions, Occam's razor would work in your favor, and between time travel and FTL spaceman, time traveler would be chosen, because it would have less assumptions. Since the astronomical events came from random points in the sky, it would be impossible to exist one place in the universe where these events could've been seen before being seen on earth (due to lightspeed limitations, it would need to exist one point in space nearer ALL events than Earth - assuming space is quadridimensional like in Einstein's relativity), and that there would be one observer with FTL capability at that point willing to come to earth to lie about being a time traveler. Just being a bona fide time traveler would have less assumptions. [Answer] I feel like a strong approach could be to provide solutions for various problems of that era. Things that the top people in their respective fields have been trying to solve for many years with little to no progress. By convincing them, their feedback should influence others. * Solving (with proofs) the remaining six [Millennium Prize Problems](http://en.wikipedia.org/wiki/Millennium_Prize_Problems) simultaneously would blow the minds of mathematicians. * Bringing back documentation of cures for various forms of cancer/diseases could convince the medical field. * As so on with physics, space, etc. The biggest benefit off of this is that multiple field breakthroughs will cause so much world-wide impact that you'll end up with proof people can experience. It would be hard to say you're just a savant because research by the world's best couldn't do it either and they're specialists. A few feasible issues are * The amount of time it would take to provide this documentation and have people take it seriously. (If you could kick-start your first breakthrough, the others could accelerate.) * Whether or not these solution were indeed solved within the timeframe we're limited to. [Answer] A copy of a newspaper. Surely in the future he would have access to historical documents and newspapers among them. A copy of a national newspaper from several days in the future that hadn't even been written yet would surely be some kind of proof. Especially if it remarked on an event that hadn't yet occurred. [Answer] I wouldn't actually try to prove I was from the future. I would focus on proving the event would take place. If I couldn't prove it, I would focus on getting the appropriate response in place via a subtle, roundabout way. For example, if the event was an asteroid collision, you forge an email to an astronomer from a trusted colleague telling him where to point his telescope. If the event was a terrorist attack, you send the authorities anonymous tips and maybe even plant some clues yourself. This might be interesting in contrast to previous more drastic attempts that failed. Maybe previous time travelers assassinated Hitler too early, which caused something even worse to happen, so you agree to be his bodyguard, but send some key piece of information to Alan Turing to help him build his enigma-cracking machine that he never managed to complete in your timeline. Then you fake Hitler's suicide once it's safe to do so. Or maybe something not so subtle. In your timeline, Saddam Hussein eventually manages to detonate 3 nuclear bombs in America. After several more subtle attempts, you plant some WMD intelligence way before the event, but that's still not enough to get the U.S. government to intervene, so in desperation you perpetrate the 9/11 attacks. [Answer] You mention the option of either unpredictable natural or man-made events. If you publish a table of stock prices, then the future will change based on how people use them. What about a table of things people cannot change? Use **daily weather information** for a few weeks in the future. You can publish precise highs, lows, conditions for a variety of locations around the globe. Weather is something that is always difficult to predict, and having knowledge of what will happen will not change the outcome. Additionally, you won't have to wait for natural disasters like earthquakes to take place. After a day or two of accurately predicting weather across the globe, people should either believe that you are from the future or are the best meteorologist in all of history! [Answer] The time traveler should set new video game speed run records using glitches not currently known. For instance, there are currently still large, active communities uncovering new methods in Nintendo 64 games such as Zelda: Ocarina Of Time. This is a non-violent method which involves no money or physical objects. It minimizes introducing variables mentioned above through lottery/stock manipulation as subsequent events are not based on the outcome of the prior event (i.e., Glitch 2 in Game B will not change upon completing Glitch 1 in Game A). I am sure this method would garner the time traveler enough media attention and credibility to then springboard to convincing the public on whatever "serious" issue as at hand. As I'm typing this, it just occurred to me that this was the plot of "The Wizard" when they introduced Super Mario Brothers 3 and the one competitor knew how to get to the early warp zone. [Answer] We can already store enormous volumes of information in a pocketable medium. Bring a petabyte of (his current) Wikipedia on his pocket reader. In so many TV shows and movies, the lone traveller has to do everything from scratch, and his limited resources is the main source of making it interesting. Why not have a well-researched plan in place? The catapult to the target past might be a one-shot, but going back a week or month is easy and just a couple years is routine. They can grow their resources and make plans in a small time loop near home: each jump back improves upon the planning and size and effectiveness of the organization. They can become very wealthy and politically powerful, and recruit talent from the brightest of the population, seemingly (from the outside in normal time) by a combination of luck and omniscience. Now there may be an inherent issue with the far-past catapult in that any success at changing the timeline will destroy the "present" with its large organized effort in place. Any arrival at all will appear in a different timeline not in their own past, so they cannot send multiple loads. They can send multiple *trys* though. Each catapult seeds a new timeline and through repetition with variations on the plan the hope at least one of them turns out the way they intended. For a limited load size and mass (your phone box isn't larger on the inside?) why send a single person w/carry-on baggage? Send nanotechnological robots or seeds for robots and infrastructure. If piloted also, the person is a dwarf (or has the body of a child) to make room for his stuff. That is a detail I've not seen in stories before. If multiple loads *is* possible with the thread maintained to the new past only possible if they don't diverge (yet), set up the operation on the far side of the moon. The expedition is in shipping mode to receive as many loads as it can, and only after the thread is broken do they proceed with the mission. [Answer] One of the fairly standard proofs of knowledge of future events is to have the information sealed in an envelope, and hand it to the person you are trying to convince with instructions to open it at the time of, or immediately after, the event. The fact that the other person has it in their possession before an event happens is the proof that you knew it ahead of time. Because they don't see the proof that you held such knowledge until after the event happened, they don't get to meddle with the flow of time, there by avoiding having them take actions that would change the outcomes. If I were such a time traveler, I would probably pick sports as my proof. Pick whatever major sport was in season for my target region and have a list of the final scores of each matchup. Two weeks or so should give enough evidence to convince people that I knew what the results were going to be before the games were played. Here is the catch though. By demonstrating that time travel is a possibility, I am pretty much ensuring that someone is going to figure out how to do it. I may try to mislead or derail their research efforts, but knowing that something is possible makes it pretty much inevitable that someone will eventually figure it out. Quite possibly sooner than they did in my original time line now that people are paying attention to it as a real possibility. If one of my goals is to prevent time travel technology from being developed then I have to work a lot slower and more subtly. I have to use my future knowledge to place myself in a position of influence, without making it obvious that I am from the future. --- Edit in response to comments: The way the scenario in the beginning of this plays out is that I select the individual I want to convince and come up with a way to approach them after doing a bit of preliminary work. Once I have made contact I say something along the lines of "I have some important information for you, but you won't believe me if I tell you now. Take this envelope, wait until Monday morning to open it, then email me at the address inside after you have verified the information it contains." When you open the envelope Monday morning you find the scores at the end of each inning for all of the baseball games that occurred in the previous three days. You know the envelope has been in your possession for at least a full day prior to the first game on the list. Now it is conceivable that I could have had a lucky guess on one or two games, or possibly found someone to bribe on a few more, but the probability of me having the outcome of every game across the nation for several days correct down to that level of detail is almost impossible. (The information inside could really be anything, the key is that it is information about events that occurred after I gave it to you; It is inconceivable that I could have accurately predicted the data volume and level of detail without special knowledge; And it is equally inconceivable that I, or any organization supporting me, could have influenced the outcomes of all of those events.) So obviously something special had to have happened. Could I have tampered with the envelope after I gave it to you? Possibly, but you have not seen me since, and I have made no further attempt to contact you. Could I have been incredibly lucky? Sure, it is possible, but extremely unlikely. And however I pulled it off, wouldn't it make you curious? If I have a list of such contacts, and I work this same general scheme on each of them independently. One or more of them is going to decide to reach out to me to find out what is going on. Perhaps they do think I managed to pull a fast one on them, so offer to do it again when they can take some informed precautions. One potential tripping point in this approach is keeping someone from opening their envelope early and trying to exploit the knowledge within. If I am targeting current day, and particularly selecting tech savvy people as my targets, then I can encrypt the data, give them the encrypted file, and then wait to give them the key to decrypt it until after the events occur. [Answer] The answer is Bitcoin. Block chains are based on a cryptographic proof-of-work protocol: constructing one takes time and effort and processing power, but it's orders of magnitude easier to verify that they are correct. So either get your hands on 100 years worth of block chain data, or use a 22nd century supercomputer to generate a brand new one, of a length sufficient to impress. Load it up on as many antique terabyte drives as you can carry, get into the time-catapult, and find the nearest influential crypto enthusiast. This scheme has several advantages: Unlike the 'Almanac', the locals can start verifying right away. There's no risk of butterfly-effect: your block gain doesn't have to match anything from the 21st century, it just has to be internally consistent. You're not bringing any useful technology or information back with you, just proof that you had it before you left. Once a certain length of block chain is verified, the locals will have mathematically solid proof: Either you are a time-traveller, or you have access to more computing power than all of humanity combined, and have decided to use it to impersonate a time-traveller. Either way, it's probably a good idea to listen to you. A drawback of this solution is that it's highly technical. Once you've convinced the global mathematics community, the NSA, and Reddit, you're on your own to convince the man-on-the-street. [Answer] It's actually quite easy. Look at the stock market--this has been rejected by other posters on the basis that making a correct prediction will change the future. The butterfly effect is certainly going to be an issue. To protect against this you must make only one prediction and at a short range. Have your time machine deliver you to the Oval Office, 10 minutes before the closing bell on Wall Street. I would recommend minimal attire to minimize the nervousness of the Secret Service agents. Arrive, hand the closest agent printout, tell him to keep it secure. The printout looks like gibberish. You then explain that you are a time traveler, come to warn of a disaster. The printout you just provided is the closing prices for **every** actively traded stock. There is a simple encoding scheme, even if it goes straight to a cryptographer they'll only have a few minutes to work on it--the crypto guys simply don't have time to bring their heavy guns to bear. You make thousands of accurate predictions at once--they'll listen. Popping in from thin air will also help. [Answer] Bring forth the bugs! - pick a ton of open-source projects, such as linux, and expose all the current security bugs (exposing one won't butterfly-contaminate the others, as the code is already written, saved, deployed on all sorts of machines, and won't auto-update to fix itself) - next, to prevent the ensuing hackfest, distribute the code that would be required to fix this newfound issue - the patches, fixes, etc. - you now have proven yourself as someone with credible world-saving abilities - people can speculate as to where this comes from, if necessary you could blackmail every single government or politician in the world (or just about anyone else) - basically choose things that have already occurred prior to the date that you wish to appear in, but have not yet been revealed to the public (think snowden leaks, only much larger, over more secret organizations, with the juicy stuff selected and chosen) [Answer] By request on the comment thread, I will expand on [rmoore's answer](https://worldbuilding.stackexchange.com/a/12395/353) and detail how the DNA analysis can prove the time traveler is indeed a descendant of his great-grandparents / grandparents. [This page for a testing website](http://www.genetica.com/GeneticaWebV2.nsf/XGrandparentageDNATest.xsp) states that their rate of accuracy for grandparent DNA testing is 99,99%. If the grandparents are alive, the odds of the time traveler to NOT be the grandson of these people would be: > > 0.0001 ^ 4 = 0.000,000,000,000,000,1 > > 1 in 1,000 trillion chances. > > > Since the amount of people that ever lived is estimated at 108 billionssource [1](http://blogs.discovermagazine.com/fire-in-the-mind/2013/08/11/how-many-people-ever-lived/#.VRCicI7F_fw) [2](http://www.prb.org/Publications/Articles/2002/HowManyPeopleHaveEverLivedonEarth.aspx) [3](http://www.strangerdimensions.com/2014/07/07/many-people-have-ever-lived-died/), the explanation of time travel would be the accepted explanation by Occam's razor. The apple does not fall far from the tree. Also there is the paternal test for the Y chromosome (paternal grandfather) and the maternal test for the X chromosome (maternal grandparents) and the mitochondrial DNA testing (maternal grandmother). > > Unless his family has a huge recent history of incest, if the grandparents are already living, there would be no doubt he is a time traveler. > > > **But unfortunately, There is a great chance his grandparents are NOT yet born as of 2015.** Lets assume they sent back a healthy indiviudal, on his prime. Lets also assume that his prime is at 25 years old, and that he was born when his parents were 25 years old, and his parents were born when his grandparents were 25 years old. This would place the birthyears of our 2100 time traveler in 2075, his parents in 2050 and his grandparents in 2025. **His grandparents would be born only ten years-ish from now.** This would leave only his great-grandparents alive, in their teens. There is a trend of people having children at a higher age (with all that [egg freezing mania](http://www.businessinsider.com/apple-and-facebook-pay-women-to-freeze-eggs-2014-10) and stuff) so I think that this 25 years window is a safe assumption. Now, great-grandparent dna testing is still mostly unheard of, but [looking at genealogy testing](http://genealogy.about.com/cs/geneticgenealogy/a/dna_tests.htm), we can get 95% proof that the time traveler belongs to the family line of his father's father's father. With autosomal DNA testing, he can be placed in the family tree of all of his eight great-grandparents (and since your grandparents have not yet been born, they are all alive by 2015). Now, unless they are close relatives (like several of those couples are cousins in love), a simple venn diagram would prove that the very existance of the time traveler would be impossible if he is not a time traveler. **Proof by contradiction.** There is no other way our alleged time traveler could be part of eight completely unrelated family lines (and trace your mitochondrial DNA to a few and the Y-DNA to only one). Unless he is really the great-grandchildren of those eight families. This one has less precision (still beyond reasonable doubt, but would *give a hook for the antagonists* to descredit our hero) than the grandparents (so the very skeptic may still be unsure, specially if some of the great-grandparents were related), but with some more info about the future, the time traveler would succeed. --- Picture the adventures of a time traveler trying to convince eight teens to do agree to DNA testing, all the while dodging the evil organization and attempting to avoid doomsday. Also for bonus kicks, he tries to get the matchups of his great-grandparents right, while the teen hormones attempt to negate his family line. [Answer] A reverse-compatible (USB3.0) hard drive full of the most expensive movies, pop songs, selected news media, YouTube, selected Internet, and perhaps selected scientific publications from the year after you arrive for several decades into the future. You're either from the future, or from an alternate Earth future. However, proving you're from the future is probably a lot easier than gaining the trust of authorities, and avoiding getting abused by people who decide to behave badly when tempted by the potential wealth/power they might think they could hoard to themselves if they captured you. So, you might want to bring a device that would let you make anonymous undetectable broadcasts, as well. And other things that might help with your personal security and well-being. [Answer] Have the person you're trying to convince write a long letter, and post it to you (or your Grandfather). You'll receive it in the future. Then you produce the envelope out of your pocket, open it and reveal the letter! [Answer] A variant of the lottery numbers ploy: bring some other information which is top secret right now, but part of the historical archives in the future. That should get the immediate attention of government agencies if the time traveler phones them. [Answer] It's easier to think about what type of thing you'd bring back 100 years to the *past* that would convince people you are from the "future" (IE, Now). Our future man could easily find out what hasn't been invented yet this year and take a product from his time back with him to our time to prove his authenticity. Demonstrating his technical prowess with an unusual device that does not exist anywhere else in the world should be sufficient proof. If we were to compare it to travelling from now to 100 years ago, all anyone would have to do is take their smartphone out of their pocket and play some music. Not only would the music be strange to the listener, it would be a remarkable technology in itself - even without the ability to connect to a wireless network (a problem with any technology dependent on future infrastructure). For our man from the future, his handheld matter converter that turns common paper into hot dogs should do nicely. [Answer] **Want to improve this post?** Provide detailed answers to this question, including citations and an explanation of why your answer is correct. Answers without enough detail may be edited or deleted. I'm surprised nobody has stated the obvious: bring back a sports almanac that shows the result of every major sports event until the end of the century. [Answer] Send two payloads into the past. First send a probe (or even the time travellers luggage) to March 30. After making sure the probe is sent, then send the traveller to March 1. All the time traveller has to do is tell news agencies that his probe/luggage and maybe artifacts from the future will arrive on March 30 at a specific time and place. For a real world example of how people react to a time traveller you should also check out the John Titor story. A time traveller revealed himself on internet bulletin boards during the years 2000 and 2001. Caused quite a stir after he posted pictures of his time machine. <http://en.wikipedia.org/wiki/John_Titor> from <http://www.abovetopsecret.com/forum/thread62046/pg1> > > excerpt: This is a picture taken in the fall of 2035 during my > training. It shows my instructor beaming a handheld laser outside the > vehicle during operation. The beam is being bent by the gravitational > field produced outside the vehicle by the distortion unit. > > > ![enter image description here](https://i.stack.imgur.com/9cw8R.jpg) from <http://www.strangerdimensions.com/2013/02/04/john-titor-the-man-with-the-machine/> ![enter image description here](https://i.stack.imgur.com/gzFVF.png) For your time traveller it might also be prudent to remember that doomsday predictions can also attract the wrong kind of audience (ufo and doomsday believers) which could be detrimental when he is trying to prove his authenticity. [Answer] What if the time travel resulted in some form of semi-violent catastrophe, or publicly visible entering of our time? Since we do not know what time travel will do to our reality this might be feasible. If I knew time was of the essence, I'd make sure I'd enter with a big BANG, to get this identification process out of the way ASAP... Of course this might also result in being arrested and potentially tortured to get information. But lets assume, that the above doesn't happen, and if somehow during this process the Eiffel tower got sucked up in some space time void, or for that matter any other major publicly visible entrance event occurs in a manner that it unknown to us, leaving only our hero as the sole survivor... people will notice. [Answer] The "standard" solution to this is to predict the future. The most straightforward version would be to print out and bring along stock market data for some time following your intended arrival. It is widely believed that the movements of the stock market are impossible to predict precisely, so consistent success at this would be quite convincing. And, if everyone is still incredulous, you could just leverage your information to make a fortune and then simply pay them to do what you want. If you want the time traveler to not have this disproportionate power, you could instead give him a one way hash of the market figures - that way he would not be able to predict what the value will be, but it will be possible to determine whether he had access to the future value at any point. Alternatives include guessing lottery numbers, weather, sports competition outcomes, and so on. All of these have the drawback of being chaotic, and so if your universe takes a "butterfly effect" approach to time travel, the simple presence of the traveler may disrupt these events and render predictions useless. To solve this issue, you can try bringing back large scale historical events, which would take more than a flap of a butterfly's wings to alter. For instance, presumably a person traveling to 1913 would have a lot of trouble preventing a world war in early 20th century, even if they did manage to save Archduke Ferdinand. The drawback here is that major historical events may be predicted, and people may ascribe the prediction to extraordinarily sharp deductive powers rather than future knowledge. Lastly, you could bring back information that was already past at the time of arrival, but would not be widely known until much after. For instance, [an important shipwreck](https://en.wikipedia.org/wiki/Uluburun_shipwreck) was discovered by chance in 1982. If you traveled to 1975 with a map showing the location of the wreck, locating it would be an extraordinary feat. Some could accuse you of stumbling upon the wreck yourself, and trying to spin it into a time travel story, but if you do this for many shipwrecks (or other artifacts) around the globe, that theory will become quite weak. Besides archeological finds, you could go back with information that was a very well kept secret at the time. The nice thing about this strategy is that even if some chaotic process ruins the future you are trying to predict as proof, the past would not be affected (granted this assertion is dubious in a universe where traveling backwards in time is possible) and your proof is safe. [Answer] Actual "proof" of being from the future is pointless: the goal is to convince people, and few people can be convinced of something in violation with their belief system, regardless of "proof". How many well established scientific facts are being ignored on a daily basis? People smoke and eat unhealthy foods, even though it is fairly well established that smoking massively increases risks of disease and death. They drink, take drugs and drive. We still run and build coal fired plants even though the environmental consequences are catastrophic.... Think of the long list of patently insane behaviors people have on this planet. No matter how thoroughly something is proven, you will find people to dismiss it entirely with no evidence. Using "proof" to convince people to do something is sadly not an effective way to get them to do things. Suppose someone were to give **you** abundant proof of an upcoming catastrophe... what do you do next? Who do you contact and how would you go about convincing the people in power and the concerned population to follow your orders? Proving one is from the future is not just impossible, it's also pointless. If the goal is to convince specific people not to take a specific path, proof of time travel isn't going to do the trick. Better come up with a carrot, a stick or both to get these people moving in the right direction. [Answer] People seem to be thinking small in terms of "data points required to not just be a charlatan." Rather than a single lottery or a series of sporting games, why not just correctly "predict" the full intraday pricing on a second-by-second basis of, say, 1,000 equity options ? * Stock option prices are governed by stochasticity, i.e. any given moment a stock option's price is just as likely to go up as down. * You may be able to rig a lottery or a sporting match or two, but rigging an entire open market is ... unfeasible. So that's 1,000 stock option volatilities \* 28,800 seconds in a trading day = 288,000,000 basically coin flips you accurately predicted. ]
[Question] [ **Closed**. This question needs to be more [focused](/help/closed-questions). It is not currently accepting answers. --- **Want to improve this question?** Update the question so it focuses on one problem only by [editing this post](/posts/18051/edit). Closed 7 years ago. [Improve this question](/posts/18051/edit) You wake up tomorrow, and it's Wednesday again. Everybody remembers it, but whatever was physically done today is undone. Your favorite mug, which the dog knocked over, is un-broken. The kid down the street who got hit by a car -- his leg is just fine, and the bike is okay, but he remembers the pain. People are pretty freaked out, but no one does anything rash. (Mrs. Kendall keeps Johnny home, though, and he doesn't get hit.) Mostly we look for news on the subject, but nobody knows anything, or if they do, no one is talking. But then the next day, the same thing happens. Lilly has gone into work for the past three days as a dental assistant, but she has had to work on the same emergency root canal every day. The next day the patient doesn't show. Who wants to go in for dental surgery every day for the rest of their life? With no reason to suspect tomorrow will be any different, her roommate buys a gun to commit suicide, just to see what it is like. The next day, he's alive again, but with the horrifying memory. But now there's proof that there are no consequences, so he robs a bank. The next day, he wakes up with no gun and no money, but the cops remember what happened, and they arrest him. **QUESTION:** I could go on, but the local is easy. My question is about the global. What do societies do? What does the government do? Anything that anyone does that takes more than 24 hours to complete is a waste of time, unless the intended result is mental. Nothing can be stored on a computer or chalkboard or anywhere. Still, everyone can memorize what they can, and agree to collaborate again the next today. How it happened is irrelevant. If it was caused by mankind, it isn't something they can just undo. But it just as easily may have happened somewhere across the galaxy, and there is no way for humanity to stop it. This takes place today, in our world, with no technology we don't have today. (Of course, if 100 years of research and 12 hours of production can make an advance, we could build it every day.) How do we deal if this goes on for years, centuries, millennia? --- EDIT: Most of the above is simply setup so that everyone understands the scenario I propose. My question is both simple and specific: **What can a government do to retain control and prevent lawlessness in this situation?** One answer so far has suggested that it couldn't, and no others have addressed this question. If an individual's actions have no consequences beyond twenty-four hours, when locking them up and even killing them doesn't last, how can a government maintain order? [Answer] This is a really interesting scenario, and one I've had a hard time thinking up some responses to. 1. **Lack of information distribution** You will find lots of people doing lots of the same stuff. Information in our world is mainly distributed electronically, through social media and email. However, it is highly likely that many people don't check all of those every day, so won't see information about the situation coming in. So, for example, I imagine you will have a lot of people experimenting with what they can do - the suicide and homicide rate will go through the roof, and if you want to imprison all these new murderers you'll need to build more prisons. You'll get an increased crime rate overall - it's horrible to think about, but people discovering this may be tempted to let the worse side of their nature out. Lots of murders - the victim will be alive again tomorrow. Lots of rapes - she won't be pregnant tomorrow, so there'll be no DNA testing of the baby. Lots of really nasty stuff - torturers, for example, can now maim their victims even more without fear - they'll come alive again if they do die. 2. **Children** To expand a bit on [Gorchester H's comment](https://worldbuilding.stackexchange.com/questions/18051/tomorrow-is-groundhog-day-for-everyone-how-does-society-respond#comment43777_18051): children are going to be very weird. For as long as this continues, they're gaining knowledge and experience, and you will end up with mature adults in kids' bodies. Any baby who would have been born on that day will be born, and they'll develop, but any pregnant woman will remain so for eternity. Unborn babies will never be born. New babies, while they can be conceived, will simply disappear the following day. 3. **Science** Scientists would be trying incredibly hard to figure out the reasons for and solutions to this - even if there are no solutions, they don't know that. New methods will be developed for memorising information quickly, and the neuroscientists will be much in demand for a while as they perfect a machine that allows us to implant things into a brain. Engineers, too, as they perfect the manufacturing techniques that allow us to manufacture this machine as quickly as possible. It will still be possible to distribute information electronically, so scientists across the world can communicate, and plans for machines like this can be sent - as long as they are received and memorised on the same day. 4. **Acceptance** Gradually, people will get used to this world. People will get used to the fact that although they can commit crime without repercussions, law enforcement will still get them, if anyone reports it - people can still be sent to prison. (Trials, however, will necessarily become very short, and house arrest will become more common as transporting people to prison every day gets tiring.) New methods of doing old things faster will become popularised and normalised, and our society, although changed beyond recognition, will slowly sink back to a regular rhythm. 5. **Society** Society, as a whole, is no longer a viable concept. Big cities break down into small communities: you will interact most with the people around you and that will be your community. Travelling anywhere will get strange, as different communities implement different policies to deal with the stuff that goes on in their neighborhood every day; perhaps a morning task for each community will quickly become posting a notice at the borders explaining the stuff happening there. 6. **Government** Government as we know it, in simple terms, fails on the spot. A centralised government will not be equipped to deal with all the small communities and their policies that spring up - and they can't possibly go round inspecting every community, every day - they just don't have the people. Moreover, what could they do about it? Someone implemented a community policy they don't agree with but that doesn't break any laws? - well, there are plenty of people breaking laws they should deal with instead. Someone implemented a community policy that *does* break some laws? - well, are you going to arrest every member of that community for trying to help themselves, only to have them released in the morning? 7. **Law and Order** Laws would get rather confusing. The law documents - the *paper/electronic* law documents - would reset at the start of every day. So, if you want to change a law, you have to remember which one you changed and then permanently disregard the old documents for that law. You also have to make sure every police officer in the country knows about the law change, at which point he loses his reference for arresting people under that law. His arrest can then be called into question - did he *really* follow the law to the letter? What if he remembered it wrongly? Arrests, as many here have mentioned, also change drastically. They'd stick around for a while, as you can at least detain someone for a day, while people figure out what to do, but expect them to be replaced in the long term. You either have to spend huge amounts of resources on keeping people in house arrest, or you need to implement quick punishments. You can no longer lock someone up for years on end, so to get the same level of punishment you inflict a worse punishment for a shorter time. Someone here suggested that torture might be taken up: for petty theft, 10 minutes of torture. For rape, maybe several hours. And, of course, you will find several crimes losing their definitions. Murder is now insignificant - kids are killing each other on the streets for *fun* now, and all it does is cause someone some minor inconvenience until the next day. It's now a bit like kidnapping someone and then releasing them a few hours later - annoying, but no damage has been done to the victim and they just lost a day. 8. **North Korea** Since you mention North Korea specifically, I shall make a prediction. One of a few things could happen: either * The leadership denies that this is happening and directs everyone to go about their daily routines as normal. Everyone who can emigrates - who wants to do the same thing for years on end? Perhaps *without* end? Soldiers desert, border guards desert, everyone leaves Kim Jong-Un on his own. * The leadership blames America or some other Western country, and launches an all-out assault. Nukes go flying. On the first day they hit, everyone in the target city decides that tomorrow, they're going to get away from the city as fast as possible so they don't get hit tomorrow. A game of nuclear cat-and-mouse ensues, with North Korean spies racing to tell their bosses where everyone is today, so they can be nuked. * They're as confused as everyone else, and try to actually be friendly for once. Information is shared about causes and effects, and scientists work together to try to solve their problems. The entire North Korea issue is solved.(Essentially, I have no idea - they're just too unpredictable) 9. **Humanitarian Societies** I predict a two-way split here, between two frames of mind as to what to do: * Number 1, the "it no longer matters" point of view - anyone who was going to die today will anyway, and anyone who wasn't, won't. Trying to get aid there won't help, and it won't last anyway so why bother? * Number 2, the "keep calm and carry on" approach - people who were going to get aid today still deserve and/or need it, so we should just try even harder to transport stuff there. We should also spend some time teaching them how to support themselves so we don't have to bend over backwards to get this done. **In conclusion** - you'll have short-term anarchy, but as everyone realises there's no point to this, your society settles down into lots of small communities, and life continues. Until, of course, the sadistic entity that caused this releases it again, and we have to try to remember what life was like before... [Answer] Since the short, medium and long term are already done, I'm going to take a shot at the *very* long term. The one where, eventually, human ingenuity and curiosity tries to adapt and figure out what's going on and how to fix it. There isn't a way to physically create anything, since any paper and even electronic storage will fail. But there's still memory in the brain. And there's a *lot* of it. # Project Last Hope Once you get beyond the various terms of anarchy, depression, hedonism, listlessness and such, at some point people will turn on their computers and go on the internet. And there, after browsing for a long time, they will run into a website that's rehosted every morning, a few minutes post-reset. It will be called "Last Hope" and will feature something that would have seen ridiculous to anyone from before the happening... the world's largest, fully organic, hive-brain storage system. Once people learn of this initiative, every morning they will log into the system and rebuild their little part of it. Each person will memorize their part, whether it's a block of code, a list of numbers and data, an algorithm, or a set of instructions. People will remember small chunks of the Last Hope website, which is rebuilt by thousands of people logging in to a massive, shared FTP server to each rebuilt their 10 lines of its content, which is strewn about in thousands of different, linked files in order to be online as fast as possible. Then after the website is rebuilt, a segment of the project will start trying to contact whatever people haven't found out yet; whether by going door to door or emailing or posting on every message board in the world. Anyone with an internet connection and an eternity to waste will eventually find a link to the Last Hope project *someday*. The rest of its members are divided into thinkers, tinkerers and storage. **Thinkers** will be scientists (either from the old world, or learned ones from the new world. There's forever to get them up to speed, after all). They will be researching what caused the resetting and whether anything can be done. They will use Last Hope project's hive-storage to keep their work going forward. **Tinkerers** will be engineers. There might not be an option to build any physical tools, but we have millions of interconnected computers that can perform a lot of work. It's their job to figure out how to get as many computers as possible into their network as quickly as possible. They are looking for exploits and bugs and make lists of compromised machines that can be used the next day. They will also improve existing algorithms; there is infinite time to tinker with them but finite time to run them, so the faster a piece of code runs, the more it will do. And since they cannot store their informatiom on the computer, that's where the most crucial part of Last Hope project comes in. **Storage** are all the people who have good memory or trained to have it. They all remember their tiny parts of the project and every morning, they rebuild their tiny part and then attempt to memorize more and more chunks. They might not understand what the thing they memorized does, but they know it helps. And it's only 30 minutes out of their day, if they don't want to (or cannot) contribute more. But together, in millions of brains, they will remember and rebuild the largest, most powerful computer program ever written by humanity. Every morning, shortly after reset, every bug in existance is exploited, every machine reachable by the internet is connected, and in mere minutes a program is put together out of a million different, small files, that will crack numbers and run data and do an unimaginable amount of work. It might take years, maybe even centuries or millenia or longer, but progress will be made. In a single day of computing, with a million minds put to the task, we will crack any problem the universe throws at us. [Answer] ## Immediate - The World Stops Most people live with relatively long-term goals in mind. They eat so they won't be hungry, sleep so they won't be tired, go to work so they won't be broke. If you only live for a day, that all changes: why work when you will *never* be paid? Why sleep when you will *never* wake up? There's a lot of things that people do that won't really matter any more, and though some will keep doing it out of habit, many will take some time off in order to discover the rules of this brave new world. Unfortunately, this may mean that some things break down. Many human-run services will become unavailable (restaurants, theme parks, prostitutes, etc), so there's a lot of fun stuff you won't be able to do. Other things, like driving, will now be very dangerous, as people don't have to worry as much about things like property damage or personal safety. I'd say walking outside might be problematic, better to stay indoors at this stage. ## Short Term - the New Normal At this stage, people will have gotten used to how things are now. I note here that human conversations will remain largely unaffected by this change; one effect of this is that people will be able to talk about their situation with new vocabulary. Everyone will find their personal universe: the total time and area that they will ever be able to explore. If you wake up at half past ten PM in the middle of nowhere with no legs, that'll be a pretty small area; on the other hand, if you wake up at the crack of dawn with a personal helicopter with a full tank of gas, you should be pretty happy with yourself. At this point, a lot of short-term problems will be perceived as permanent. If you wake up with a sore back, you now have a sore back forever. If your significant other is on vacation this week, you will never see them ever again. Off the top of my head, I can't think of any good things that you can get from this that aren't counteracted by other effects. However, some things can be fixed: inmates can be set free, and if they do anything wrong during the day you don't even have to worry about locking them up again. Of course, this presumes that someone will actually take the time to let them out, but I'll get to that. ## Medium Term - Make it Work At this point, the world settles into a routine, something that works reasonably well for everyone in power. Since everyone's personal universe is pretty small, government will only work on a small scale, but I'm sure communities and leaders will develop. There may be conflicts, but since most people are reasonably moral I don't think violence would be permanent; for instance, the local serial killer will eventually be foiled, and then part of the daily routine will involve catching him before he wakes up. Not only that, but other injustices will be prevented; if someone ever finds that guy with no legs, they may make a plan to wake him up and carry him back to the community each morning. Someone can go let the prisoners out of prison. Someone else can make sure everyone wakes up at a reasonable hour (except that serial killer, and other criminals). These jobs will have to be mostly painless, and people can take turns doing them. Honestly, overall I see this working out pretty well for most people. Small government will rule, which means that no one can get away with hurting anyone else without getting punished by it. Petty arguments will be rehashed every single day, so eventually people will have to start agreeing, even if it's to disagree. There may still be a lot of nightmarish situations, mostly involving either people with incredibly small personal universes or people with little power in a bad community, but as time goes on I think a lot of these problems will get solved as everyone comes up with new ways to get things done and just generally get smarter over the years. Novelty and memory will be of the utmost importance, and both of these pretty much rely on human cooperation. People will have to entertain themselves somehow, and the best way to do that is to entertain one another. Perhaps everyone would learn to play instruments (a great experience both for player and listener), or dance or juggle or something like that. As I said, conversations will be unchanged, so I think people will have a lot of them; anything to keep the world feeling fresh and new. So, in the end, I imagine something of a utopia of mind; the world will look the same day after day, but with every reset people will work together better, and everyone will become just a bit happier. No idea how long it would take to get it right, though. [Answer] **It would be anarchy.** Cyclical anarchy. I'm assuming the reset occurs globally, not per time-zone at midnight. Though a reset-[terminator](http://en.wikipedia.org/wiki/Terminator_%28solar%29) racing around the planet is a pretty cool idea. Many people would have various ideas about what is going on. Some might think it's purgatory. Others might see it as hell. **Find Bill Murray** I imagine anyone within a day's travel from Bill Murray would have some questions and/or beatings for him. He might even gain a religious following, since he's been depicted as escaping such a situation. Trying to right all one's wrongs would be a little more difficult if everyone else still remembered those wrongs though. **Research** The best avenue for research would be why the brain is the only thing which is not reset. Crude experiments could be performed: does an implanted flash drive stay there from yesterday? What about dura mater tattoos? Do dogs also remember? What about mice? **Steady State** Likely things would eventually degenerate into cycles of hope and despair. Multi-day runs of depression might give way to a renewed will to try and do something positive with the situation. But everyone will burn out on anything after enough time. Even if people begin to work together, someone is going to crack. That person doesn't just leave, they come back again and again, not having release from the stimulus that drove them insane. **Varying Situations** People would become very familiar with anyone within a day's travel of themselves. * Some would envy those who were just waking up at the start of the reset, ready to do something for 24 hours, others would envy those who get to sleep away the repetition. * They'll pity the recently wounded, who must suffer through their pain over and over again. * There might be one man who always murders his neighbor who wouldn't have woken up until 6 AM. Spawn camping, as it were. * There would likely be isolated people who have no idea anyone else is experiencing the same thing, because they're more than a day's travel from other people. [Answer] **TL;DR**: A very bloody anarchy, followed by an intellectual bloom and finally listlessness. If every day is the same day, law enforcement becomes moot. Sure, you could arrest Fred for robbing the bank, but what's the point? You can only hold him until midnight before he's back on the street. Even if you could rush him through the judicial system, there's no point: he won't stay in confinement. You could repeat the process every day, but how many people are going to be doing the same thing? Because Fred didn't rob the bank, now George can. So arrest George too. Because Fred and George didn't rob the bank, Alex did. So arrest Alex too. Eventually, the police spend all their time trying to keep up with arrests when the criminals are just going to be free at midnight. So, law enforcement goes out the window (don't worry it'll be back at midnight for a brief showing.) The arts will take a hit as well. Anything that has a material result, such as a painting or a hand-crafted chair, is going to be a no go. Authors, painters, and architects all lose their work every day. Gamers will suffer as well. Know that boss you struggled with for a week that you finally beat? Sorry, but you have to face him again tomorrow. And the day after that, and the day after that... In short, anything that has a material product is out the window (don't worry, this will make a brief appearance each morning, too). So now we come to the point about anarchy. We have removed any useful application of law enforcement and there's nothing people can do to keep their hands busy without driving themselves insane. So people go out on the streets and (*gasp*) interact with each other. At least we remember the conversations we had... Oh wait. Jane remembers that Joshua beat her up yesterday, so she's going to take out revenge before he can do it again. This leads to the largest mass killing the world has ever seen. And each day, it just gets bigger. At some point, escalation results in the vast majority of human society vanishing from the face of the Earth each day, at least until it's clear that it doesn't matter how many times it happens *and* we give up on the concept of "An eye for an eye." When will that happen? Not sure. It's kinda been around awhile, even modern societies have the death penalty (you killed Clemont, so we kill you). Scientific communities, on the other hand, will be both rewarded and annoyed. The people working in Cern on the Large Hadron Collider are never going to get any more work done, it just takes too long to prepare everything and analyze the massive amount of data that comes out of it. Philosophers will have a field day, however, they can debate to their hearts' content and remember everything that was said from the previous day. After all the anarchist bloodshed, there will be a growth in philosophy and theology. Death becomes meaningless (except to those unfortunate enough to be slated to die every day) and the value of life vanishes. If this effect happens across the universe, we'll never be able to answer questions like "Is there life out there?" We can develop all the theories we want, but we'll have to start from scratch on everything we produce. We have no production any more, which leads to an interesting consequence. If there's no reason to make anything, then why go to work? If the majority of the population isn't going to work, then why should the people who run the public utilities go to work? Why should they burn away their day when everyone else is sitting at home watching reruns of *Law & Order* (not that they aren't already)? It's not like *not* going to work is going to impact anything. If something breaks, it'll be repaired tomorrow. No problem. So we lose some power generation. Let's look at the extreme case of power loss, though. Active nuclear facilities are always in danger of going critical. Let's suppose a critical part fails one day. Now we have a new catastrophe and, the next day, the workers are back on the job, much to their displeasure. After all is said and done - quite literally in this case - all that's left is to do nothing. So, after all the bloodshed, tears, and philosophy, we come to the point where everyone just lazes about, waiting for the next day when they will do the same thing. This'll lead to listlessness and, for those of us with extremely active imaginations who now have no reason to apply that ingenuity, depression. For the more depressed, suicide becomes a daily thing to avoid the daily lack of activity (don't worry too much, they'll be back tomorrow). [Answer] If we were taking more of a science fiction take to this: It would be an interesting twist, if there were a time zone delay... Think a phenomenon that cycles around the planet, racing the sun to delay the reset. This reset would probably be based on matter and it's position. So once you stop it would be back to original day 1 state. Items that don't get hit, would be missing from their original position/state. In time things like this may happen: * Flying city where people live normal lives, would be quite a story about getting it started, say a cargo plane in constant refuel, fuel vapor gets hit and resets back to base camps. * "normal" people taking to shooting things out of the sky to prevent people from cheating eternal-life... * Depending on the origin of the phenomenon - terrestrial or solar? One way trips into space? * Would people discover a type of shielding - say the scientists researching dark matter deep in the earth are unaware of what is going on? Keep getting repeating transmissions, would sending someone out - would they reset back or be gone forever? Say maybe a quantum state where matter is bound to a starting point? Anyway this was just some thoughts on possible tangents/loopholes to explore... [Answer] Fundamentally, this is * a post-scarcity society * in which everyone is immortal (if the loop keeps happening) * in which nothing new can be created * in which there are no physical ramifications of anyone's actions I say post-scarcity because the amount of food in nearly every home and every grocery store is more than enough to feed everyone for one day, no matter how much they eat. Your car will always have gas in it. You've got a closet full of clothes. There are empty homes and apartments and hotels that homeless people can walk into and live in every day. We've got plenty of electricity. And so on. The results of these factors (post-scarcity, nothing permanent can be created, everyone's immortal) will lead to people bettering themselves. They'll learn arts, languages, new skills. All "creating" will be reduced to things that can be done in one day. People will find they can accomplish more in teams. There might even be fun competitions to see which teams can create "more" (the biggest machine or contraption, the most elaborate work of art, the most incredible computer program) during The Day. We'll find out who we like hanging out with, and over the decades and centuries many of us will make new and different friends. As others answers have stated, we'll quickly find out how far we can travel during The Day. That will be our particular universe. For the novelty of it, since we're immortal, we'll wind up exploring every nook and cranny of it. We'll also eventually place a premium on communicating with people outside of our particular universe via video chat, telephone, etc., and using those same technologies to explore other parts of the planet that we can't (comfortably) reach during The Day. After a few years or decades we'll want to see more than our personal universe has to offer. . And most importantly, no one will have to eat healthy or go to the gym. Hooray! [Answer] There are some excellent answers here about science, philosophy, crime, and "What if you're having a bad day" scenarios. I want to talk about entertainment. People would read every book, watch every movie, check out every TV channel, view every YouTube video, and go through everything on every DVR they could find. After they had consumed all of that, the celebrities of the planet would be those who don't rely on a script to tell or act out a story. The celebrities would be those artists who can create a beautiful new painting every day. The celebrities would be improv comics. The poets. Dancers. Bloggers. Vloggers. Anyone who can create a work of art within the scope of one day that can also be enjoyed by others before the day is done. (The art could be something they'd started before time started looping; they would be a celebrity if they could complete it in a new way each day.) [Answer] Disclaimer : This is not as generic and complete an answer as the others have already given. This is just a part that I feel is very important to include. --- Initial effects have already been stated by many of the other answers, so I'll focus on the long-term. As @DaaaahWhoosh said in the comments... ## Memory will be the most valuable resource there is I would have to disagree with @FrostFyre's end-game which is > > all that's left is to do nothing. > > > What I think is people would realize that there is still one thing persistent in this world - **their memories**. In a world with no permanent or long-term needs for health, exercise, dental check-ups, or what-have-yous, we'll focus more on what I believe is the core reason for living - **having fun**. Eating good food, enjoying intimate relations, having good conversations. The things we'd love to do if we didn't have money problems, if we didn't have work, if we didn't have (long-term) responsibilities. **Happiness** would be everyone's goal. Playing games are still viable. Sports? Your body won't physically improve but the way you play can grow with your memories. Want to play RPG games? Well, there's tabletops (D&D, Pathfinder) and the players can just recall their campaign. Their memories hold their "saved games". MOBAs? No problem. You just won't have a persistent game history, but you will definitely grow and improve as a player. --- **tl;dr**, happiness will be the main goal. Our memories will be our main resource and our activities will revolve around what our memory can "turnover" the next day. [Answer] Time is the new power. Whoever woke up first that day is the new authority within a certain range of travel. Disagree with them? They will kill you first the next day. They will find like minded people and wake them first. Only way to effectively stop new criminals is to kill them before they wake up. Eventually suicides will start hiring people to kill them before they wake up. What of the enforcers though? After 100 years of methodically working through their first 3 or 4 waking hours efficiently killing every new criminal, crazy, or suicide in their area? What of their mental state? Will they even remember why the kill certain people? Even if they started out lawful in their application of force, as lines blur over a century how will it change? [Answer] This is a thought provoker! But, since we're talking about stories, my mind immediately jumped to the 'gotchas' that would make forming a society difficult. **Would people still work?** If each day was a repeat, would there be a compelling reason to clock in each morning at McDonalds to cook for people? Would a bus driver bother getting the bus going? Why plow the snow if tomorrow is the same? **Would basic infrastructure be working?** Would anyone bother to reboot the web server for the day? Change that lightbulb? Or, perhaps the bigger issue...would anyone that works for the power company bother to go into work to actually provide power for the day? I'm thinking that would all fall apart pretty quickly. The next question would be...would it return? If *everyone* remembers each same day from day to day, perhaps verbal agreements could be made. Joe, you come in 'tomorrow' and fire up the generators. Bob will come in the 'day after' that. Then Sam. So, initially, people may go the free-for-all route. But that can get old. And at some point, humanity may wish for a semblance of routine and return to the routine and start going back to work to bring back a bit of order. The success/failure of that may be varied from locale to locale but, over time, if enough regions leave the power on, and the cable on, word can spread. If all of that succeeds, one scenario is a form of Utopia. No one gets older. Everyone works minimally (only infrastructure and service jobs are really needed). And there's plenty of time for leisure. Everything is free (as why bother with money for a day?) There is a catch, though, and that, of course, is that society somewhat stagnates as there's no way to record information for the next day. It all has to be stored and shared verbally. Day by day. That might slow down the progress of human knowledge significantly. On the other hand, with each day a repeat, and all that leisure time, perhaps word of mouth is ideal and we all slowly learn all of the things we never had time to before. **There would be casualties, though.** As others have pointed out, for most people, this would be a nice way to spend each day. But for anyone that is suffering at any level, this could be a nightmare. If you in your last days of a painful disease, or are injured every day in the first 10 seconds. Or simply depressed. Having to spend every day in agony over and over will surely create despair. Or those that are alone somewhere without an easy way back to civilization within 24 hours. Being alone for the rest of your life could drive someone insane. [Answer] **Death would be meaningless** More or less. The memory and pain would remain, but after the tenth, twentieth time, I'd imagine it wouldn't be *that* bad. You'd get used to it. And with death lasting a matter of hours, the fear of it would diminish rapidly. With death being so meaningless I wouldn't imagine it would be such a huge crime as it is today: at most, you're wasting someone's day (killing someone in a particularly painful way *must* remain a crime, however. We wouldn't want sadists running free). Griefing would become a major annoyance. We've all seen that one guy who waits for you to spawn before killing you *immediately* in every online game ever. The second of pure annoyance when you wake up and spot your neighbour beside your bed, shotgun in hand, would be enough to cause people to do it. You'll remember, and you'll wake up annoyed as hell, but in truth, in this new society, it's not much more than camping in a video game. In the same vein, pranks among children (and some adults, most likely) would become popular. Setting up death traps to kill your friends would be hilarious once the fear of death has faded. As always, with pranks come bullies who take things too far. The bully would set up similar pranks, except his (or hers) would be painful. In our society, we steal our friend's phone as a joke but the bully would smash it. In this new society, we would jump out from behind a corner with a pistol, where the bully would jump out with a blunt knife. Games would have much larger stakes. Who needs paintball guns when we can just use rifles? And computer games would vanish. Wanna play GTA? Let's go rob a car, it will be back in the morning and would we be *really* inconveniencing anyone that badly by taking their car, when it will be there when they wake up anyway? Assassin's Creed? Forget it, let's just go assassinate the grocer. But that's short term. Long term, huge arenas would be constructed, video games made real, with spectators and bets. Who remembers that old TV show, *Raven*? Y'know the obstacle course where if you get hit you sorta fade out of being, and appear beside the course, unharmed? That show would be a lot more fun when if you mess up, you die. I mean, who cares, you'll be fine come the morning. --- **Regarding JDługosz's comment** Good catch! Advertising would be as normal, I'd imagine. Word of mouth, flyers, posters, very basic local T.V. or radio ads: since people retain their memories they would remember the adverts -- for sanity's sake, all adverts bar word of mouth wouldn't really be needed too often: once a week, once a month (assuming, of course, that the society retains these concepts with every day being Wednesday). For the construction of the actual arena, I'm sure a simple thing can be knocked up in a couple hours, especially since people would be faster and faster in constructing it over time due to practice and the urgent need to get it done quicker will result in shortcuts being found. This sparked a new idea: blood games would return heavily. Gladiators would become popular and there'd be no real risk. [Answer] While most answers deal with the short term impacts, lets try to explore some of the long term results of it. I think it very much depends on how our memory capacity will work and deal with this situation. ## Unlimited brain capacity This is more unrealistic, but hey, we already have groundhog day (and in the original he was trapped there how long? 10000 years?). You will remember everything, and since the environment you interact with is limited, you will reach a point at which you have done everything that your moral allows. Everything that is fun to you has been repeated to the point that it is no more fun. I think this will inevitably lead to an adjustment of your morals to be able to do more. As a result, the moral of the whole society will shift into a more archaic version. For example, in the dark ages, it was fine to kill someone for various minor things, and the society accepted it. Now that killing is just another way to hurt someone badly, it will play no role anymore. Shoot someone in the head? Who cares, really, he will likely not even be able to remember any pain. So all that counts is pain that can be remembered. But even then, after yet another while, we went through all of this, are used to it, and don't care anymore. Lying on someones table and being tortured to death? Just yawn and wait for the reset. Novel ideas will die out at an exponential rate, so after a while everyone is bored to death; going anywhere has no meaning at all. Occasionally someone comes with a new idea what to do, which will spread over the world rapidly. These occasions get exponentially fewer. And less exciting from our point of view. I can imagine a situation where someone twitters a new recipe for cockroaches. Exciting. Never tried that taste. Will it taste good? Doesn't matter. It is something new. Input. Where can I get one? And the hunt begins. People will kill each other over catching a cockroach. Eventually everyone did taste one, and will fall back to some dull semi sleep state. Neuroscience indicates that what keeps the brain alive is new stuff, new input. If there is none, we not only tend to be bored, we reduce brain activity. In our case, this might lead to being able to sleep through days, weeks, months, years, centuries... eternity? ## Limited brain capacity This is somewhat easier to grasp, after all, we tend to remember less, the further away events are. If this continues, we will forget things. Forget that we met someone (given there are enough other people around us), forget that we did this or that already. Forget that someone did something awful to us 500 years ago. We will always have something new to discover, new to learn. At least if there is enough in our vicinity and we are not one of the poor bastards that are in any way confined. We will have much more ways to improve on our morals and live to moral standards. If there is enough to explore within the time it needs to forget it, there is little reason to act as a bad guy, unless of course you are a psychopath. After a while we will forget how this all started. It will just be the state of how things are. In the beginning people tried to figure out what causes this and how to revert it, but after running into many dead ends, they will forget about that. There are so much other things to see and to explore. ## Some general other thoughts There are other random things that may play a role. For one, why not start a global nuclear war from time to time? Nice fireworks, and really, if you are sitting for hundreds of years in front of this button, and hitting it has little difference than altering some peoples memories, why not do it? Also, I think we will lose all means of timekeeping. At least after we forget the beginning, there is no sense at all to talk about time. Who cares about when something happened, or if it happened at all. Wealth and money will lose their meaning. Yes, you may rob a bank (though likely there would not be anyone working there today) but what are you going to do with the money anyways? No one will want it. We will organize ourselves to get anything for free that is within our reach. And finally, behind this is lurking another interesting question... if after a billion or more years of this, groundhog day suddenly ends, what happens? No one will notice during the day, but only when the reset didn't happen... [Answer] The question states that memory survives. But beyond that, nothing changes. Society will become based on what can happen in 24 hours. As noted in other answers, the long-term problems of society are largely solved. There's no more food shortage, there's no shortage of fuel, or any material goods, no incurable disease, or global warming. In fact, there's not even a way (or reason, really) to execute large-scale war. Science will focus on four topics: ameliorating pain, intensifying pleasure, intensifying pain, and getting out of the loop. ## The Final State With no threat of death as we know it, and no long-term problems to solve, government will eventually have one simple mission: maintaining order. Governments will be necessarily weak, since people can decide on a daily basis if they want a revolution. The exception could be large families with weapons, who could consolidate power over small areas and become despots. I think even family ties will eventually erode though. Business will be transacted with verbal agreements before professional witnesses; probably older people. They will have the job of publicizing any agreements made and ensuring that both parties keep their word. Breaking a contract/being dishonest will incur a penalty, plus lose the ability to make deals in the future. The mechanisms of enforcing order will be generally limited to 1-day events. Execution will be a common form of punishment, probably for small offenses, since it causes intense immediate pain, but no long-term effect. While multiple days of pain can be threatened, the time involved in tracking down a criminal will probably mean that only the worst of criminals will be punished more than one day in a row. Public, corporal punishment will become normal, with the degree of shame or pain determined by the severity of the offense. Especially recalcitrant criminals would eventually be driven insane by mental duress of repeated executions or stop committing crimes. Good behavior will be rewarded by corresponding pleasure. Economies won't exist anymore beyond mutual favor trading. People with large amounts of Ben & Jerry's in the freezer will find themselves very rich in the new economy; while cash/durable goods will be not valuable. The focus of those who seek to learn will be to find simple, effective tools that can be built quickly, like the website mentioned in the other question. Daily life of most people in Western societies will focus on exchange of favors - for example, borrowing the flat screen TV for a day in return for supplying the food for a party on a day. That may take several days of smaller tasks to bargain with the store owners/people who just went shopping. Tourism will also be popular, since the fuel is free, it will just be the time for the pilot to fly to wherever you want to go. A merchant class will develop traveling 6 hours across what used to be borders of less developed countries, bringing valuable items. Less developed societies will focus on learning for a while, eventually perfecting techniques of raising the standard of living within an hour or two and enjoying it for a day. Since you'll have the same ingredients to cook with every day, spices may become very valuable...but that's a rabbit trail. The most valuable people will be those with skills at bringing pleasure and novel experiences; eventually there will probably be guilds as people focus on learning one area really well. Highly valued skills you might not expect would include pilots, translators, woodworkers and smiths who can quickly create functional objects, operators of large machines, musicians, and artists. ## Getting There After the initial shocks of anarchy, which I don't think will last very long, governments will devolve significantly more power to localities to prevent losing them all together to independence movements. Government will shift to focus on immediate protection of people in it's circle; otherwise people will rebel and form their own governments. The capitals and surrounding areas will remain under government control, and military bases will probably remain loyal since the soldiers respawn there each day. Eventually, smaller governments will become the norm, the size of 6 hours of travel. Those with control of weapons will stay in control at least in the medium term. Governments, even the most despotic, will be eventually insurrected by ideas, which spread as military power does not. Eventually ideas, the basis of revolutions, will soften key parts of the military, and the government will loose the ability to project power. [Answer] Is it THIS world we're talking about? Because we'd be doing ourselves a disservice if we fail to talk about belief systems. A great many people would probably keep track of "what day it would have been" if days had never started repeating, and we would likely still celebrate our birthdays and anniversaries, even though only our minds are aging. Those who had accumulated vast fortunes would now have the opportunity to splurge, and make this world their playground... Up to the point people still value currency when they've only one day to spend it. With the exception of vending machines and such, it would be much easier to spend money in the morning than it would in the afternoon... Though I can't see people entirely doing away with certain creature comforts or long-term investments, on the off chance that time "starts up again". Many religions would disappear, or be reformed at least. Everyone could, and probably would, experience death at some point. When the day resets, the now-living would realize just what happens after death, at least, on the first day post-mortem. That is, if death still happens in this world (see [Torchwood: Miracle Day](http://www.imdb.com/title/tt1798034)). Society might change in myriad ways depending solely on this "afterlife experience"... Are there deities in the world? Do we all see certain ones, or do we each see something different? Are there grim reapers? Are they more like [Discworld](http://wiki.lspace.org/mediawiki/Death) or [Dead Like Me](http://www.imdb.com/title/tt0348913)? Is there an astral plane? Is it more like [What Dreams may Come](http://www.imdb.com/title/tt0120889) or [Wristcutters: A Love Story](http://www.imdb.com/title/tt0477139)? Is that "tunnel" people talk about something everyone experiences? Are there really loved ones on the other side, or just a cold dark void? How could we experience cold and dark, unless we're still experiencing, and why are we experiencing it? Do we reincarnate immediately, or do we all stay trapped in our bodies while coroners drill into them, like in that [Tales from the Crypt episode](http://www.imdb.com/title/tt0716824)? If the latter, then we would most certainly change coroner practices! Unfortunately, you can't teach an old dog new tricks. Abrahamic faiths would still be a thing, even if the afterlife was "just darkness", since they would tell you "the dead lay dormant until the second coming" or whatever. Any "afterlife evidence" pointing to any other religion is just "a trick by the devil" to "test our faith", and any astral plane is "proof positive of purgatory". Some would call Groundhog World 'Hell', and some would call it 'a gift from God for a second chance'. Evangelists would call it a sign of the second coming, and we would all be sick of hearing that quote in Proverbs about the dog vomit. Of course, if it was a Sunday that was repeating, people might get tired of going to church every single day. New religions would most likely spring up, specifically to explain the repetition phenomenon. "We have all died, this is the afterlife!" probably would be the callphrase of most common religious view. Death-cultists, who consider it a glory to die and explore the afterlife experience (or lack of one). Kill-cultists, who believe this is a new game of some kind, and the object is to kill the most people, or all people, to achieve "the next level". New militias and enforcement agencies would certainly spring up to attempt to prevent these types of terrorism... [Answer] To recapitulate the problem: At some fixed point in the day (maybe midnight, maybe 6am) everything is changed to the exact same state as 24 hours earlier, except that people's memory contains the complete 24 hours. Difference to the "Groundhog Day" movie is that in the movie, only *one* person kept their memory. I would assume that not only the memory remains, but also memory-based abilities (so taking driving lessons or learning to play an unknown piano piece would work), but body building and the physical changes that you have while learning to play the piano wouldn't work. It should be clarified whether seasons are changing or not (presumably not) and whether the time of change is the same around the world in absolute time, or in local time ("same in absolute time" would mean different clock times depending on where you are on the earth). Some things wouldn't be of importance anymore: My physical state and my wealth at the end of the day (at the switch point). I would still continue living for many years, except that I am not ageing, and I start every day in the same state except my memory and some abilities are changed. If someone makes the day unpleasant for me, that's bad. If someone makes every day unpleasant for me, that's very bad. On the other hand, a pistol duel one minute before the switch might be harmless. I assume that people want nice lives. So any work that is of long-term benefit would be pointless. I wouldn't bother fixing my leaking roof. Working for money is pointless if I have enough for the day. Since working for money is pointless, charging money is pointless as well. Which means nobody needs money anymore. So how does this affect things? Someone works at McDonald's. Gets shouted at by their boss, but needs to keep working. Not anymore. People still like their burgers. So they come to McDonalds, nobody works, the second day even the manager isn't there. So what happens? People contact the workers at home. Offer them money. Or nice presents. Someone says "if you serve burgers for two hours, you can drive my Ferrari for the rest of the day". Suddenly McDonalds is open again, workers making burgers, paid in whatever presents people give them, volunteers being shown how to do it, and everyone has a good time. The manager tries to stop it because the restaurant takes no money, the police are called and decide that no harm is done. Two weeks later the desperate manager puts fire to the place. Next day the restaurant is back, police tells the manager not to do that kind of nonsense again. So everyone just has a good time. Four dozen people in town wake up with hangover every morning and have no tablets. After a week they have enough of it. They ask their chemist, and for two weeks they try various treatments until they find what works best. From now on, every morning the chemist puts a box with four dozen hangover treatments out of his front door, he knows by heart what to put in there, and four dozen people come to the chemist, pick up their medication, and leave some present for the chemist. Book reading circles would get lots of new members. People would come together to learn to play music. Lots of fun when you get better and better. I could see that in a few weeks or at most months, people would organise their lives to make everyone's live as comfortable as possible. How would this work with crime? Relative powers (police vs. criminals vs. everyone else) wouldn't change. Some crimes wouldn't be crimes anymore. Like selling drugs - assuming that drugs are not addictive through the switch; if they are then selling drugs might become a bigger crime than it is now. Theft would (1) not matter, and (2) be pointless. However, over some time the police would know every single criminal and drug dealer. So everyone causing physical or mental harm would be known to them, and they would probably act on it. What would be the punishment to keep someone from beating his wife? Question is whether psychological treatment would help. Question is whether punishment would help - being handcuffed in the morning without food and water for a day, longer for repeat offenders. At some point these people would give up and just leave every morning, and do something that's fun instead. So all in all I am quite optimistic how this would work out. People will try extreme and dangerous experiences, but not very often. [Answer] I think people will come up with a new unit of time thats not days, weeks, and so on. Something that has to be memorized since nothing physical can be saved. I'm actually not so sure how this can be done and communicated on a global scale without losing accuracy. Actually, using this data, some one smart can think of why this is happening. A whole new science can be born out of studying how time works in different parts of the world. P.S. Finally we can have Time Cops :) [Answer] Society only continues when people do the same thing they did yesterday, no one will want to do that when there on no consequences, no rewards. The only constant is memory so over time people will literally live in their own thoughts. We'd develop lucid dreaming to do anything we wanted, the 24 hours would not matter as one thought would run into another "day's" thought. Over time we would figure out how to communicate telepathically, maybe link up each others minds, and create a new worlds inside all the Earths' people's minds; or a single World created by everyone. Worringly, perhaps we are living in that World now... [Answer] My take on this is to think of how a particular project would work, and the types of people who would contribute. I choose putting on a new performance of a play. Once everyone has viewed every recorded performance until they are bored of it, new performances will be valuable projects. Of course, it requires a director, producer, and cast. The producer will need to have a very good memory, or have an assistant with a good memory, to keep everything organized. In the early stages, the main outside help they will need is someone with a good Internet connection and printer to print copies of the script each morning. Dress rehearsals and performances will need a lot more help. Actions will have to start at 12:01 to get everything done in one day, so the root of the phone tree for the project will have to get into a list memorized by someone who was awake and near a phone at midnight. Their contribution to society will be to place wake-up calls to a few memorized numbers each morning. Someone who lives near a fabric store and has a car will be in the early phone tree. Their task is to break into the fabric store, with the owner's permission, collect the fabric, thread, and notions for the costumes, and deliver them to the costumers. Each costumer will have rehearsed drafting the pattern, cutting it out, and sewing it for one costume. When they are just rehearsing they can sleep in and start at their normal getting-up time. On dress rehearsal and performance days, they will be in an early phone tree so they can start drafting soon after midnight, and be ready to cut out when the fabric arrives. Similarly, the set builders and painters will rehearse constructing the sets, working out how to build them in no more than 18 hours. They may need someone to break into a hardware store, with the owner's permission, to collect paint and other materials. The lighting people will rehearse hanging the lights and setting up the control boards so that they can do it in 18 hours. If the performance is going to be streamed to the Internet the camera people will also have rehearsed setting up. A successful performance would be to the advantage of a large number of people, so I assume a lot of cooperation to make it happen. Even if the fabric store owner does not like theater, the chef who loves live performances is much more likely to ask them to dinner if they cooperate. Society could operate either on informal barter, or on a "currency" with accounts managed by people who have both very good memories and very good reputations for honesty. [Answer] I won't give a complete answer because the other answers here are sufficient. But I don't think the concept of money has been fully explored. This might work well with Erik's Project Last Hope [answer](https://worldbuilding.stackexchange.com/a/18125/2638). # Money ### History (skip if you don't like historical economics) Most small tribal communities worked with credit systems1 where "gifts" were remembered and repaid with more "gifts". Money was not needed because it wasn't hard to remember that you had given your neighbor a pair of shoes (after he complained about the hole in his). The cycle of gifting was a fundamental part of their societies and worked very well on a small scale. But this made short (village to village) trade hard and long distance trade impossible. So, if trade became desirable, people turned to some form of bartering. And, out of convenience, more efficient bartering techniques were developed along the lines of: 1. A general purpose value item (like hides) becomes an intermediary that avoids the "double coincidence of needs" implicit to bartering. i.e. Everyone trades their stuff for hides and then the hides for other stuff. 2. Large, well known traders start making trades between each other in promises (notes) to avoid having to transport and actually own the item in question. 3. Coinage develops as a more stable and permanent replacement to the intermediary value item. (This usually coincides with a local gov taking over and taxing everything). And then something happens and Fiat currency emerges. But I'm not an economist and my views of fiat currency are rather biased. So rather than making amateur mistakes about it, I will leave it out. ### Function Fundamentally, money is a way of storing value for the purpose of trade between strangers. Specifically, it is: * an abstract form of *universal* value * tied to something mostly permanent but fairly arbitrary (like rare metal) * Accessible and tradeable ### Groundhog Day Money On the local scale, we would likely revert back to a credit-based society (of some form) since credit (positive or negative) would be the only type of value that would last beyond midnight. But this means knowing everyone you interact with or forming "tribes" that remember interactions on different scales. Once you want to move past this kind of society, you need some form of money. Since memory is the only permanent "thing", it must be memory based. And therefore information based. Naively, you could try to get people to remember how much money they all have. But this would require a significant portion of the population to be involved and prone to all sorts of errors. Instead, we should look at current tech: what do we have that stores value as information? **Bitcoin**, of course. Memorize the block-chain, memorize your address, what could go wrong? ### Custom Cryptocurrency So Bitcoin has some problems of course. First the block chain is huge (20gb atm and growing). That's a lot of data to memorize. Even your address is a bit long and random. But this is all because it's meant to be stored and processed by computers. Also because it's meant to be "mined". (Interestingly, you could keep mining bitcoins if the blockchain was memorized). We have different needs for our cryptocurrency. * Small, non-growing "blockchain" * Extremely robust system for distributing the blockchain to be memorized and collecting it again in the morning. * Blame mechanism plus redundancy. (motivate people to not make mistakes and make mistakes survivable) ### Timeline I imagine this to be relevant sometime after local affairs have settled. Some form of community has stabilized in your local area and you are once again interested in "progress" and a feeling of something other than futile repetition. It starts small, maybe goes through a few phases, and then starts spreading around the world as people realize they can start progressing again. That their actions today will actually have some effect on tomorrow. 1 Contrary to popular belief, tribal communities were almost never "barter" economies but something closer to credit economies. See [Debt: The First 5,000 Years](http://rads.stackoverflow.com/amzn/click/1612191290) by David Graeber [Answer] ## It would be a global reenactment of the Zimbardo prison experiment People are not basically good, they act in a way contingent with the society they find themselves in. The notion that most people are basically good is false. Most people appear to have the capacity for casual brutality if the situation allows and expects it, as demonstrated by [Zimbardo](http://en.wikipedia.org/wiki/Stanford_prison_experiment). It would after a while become apparent that the only things with value are experience and memory, the more extreme the better. Experience can take many different forms. I would anticipate that many people would simply take a gun and go hunting. Expect fighting in the streets degenerating into fantastically detailed levels of barbarism as the decades, centuries and competency levels of the participants progress. Those with access to the nuclear launch codes would use them, not once but day after day. Death from above would be frequent, unpredictable and arbitrary. Those with access to enhanced weaponry such as warplanes would treat them as toys, strafing neighbourhoods and stadia. People without access to such advanced toys would band together to storm military bases, fighting each other for access to the biggest bang, the best experience. It would be hell by nightfall, mountains of burning corpses, screaming madmen in bulldozers, aircraft exploding in mid air and raining burning bodies down onto neighbourhoods. Children with the minds of war ravaged old men murdering their parents in their beds and laughing. There would be no escape, you would be trapped forever. No permanent consequences, no right or wrong, kill me today and I'll come right back at you tomorrow. [Answer] I suspect this would happen in the following stages: 1. Confusion 2. Experimentation 3. Lamentation 4. Re-organization 5. Acceptance Similar to Groundhog day, the first several days would be confusing to most people. I think they would figure it out after a while, but not at first. This would gradually lead to the next stage, experimentation. Once it became known exactly what was happening, there would probably be a mixture of reactions. I suspect that the general thought would be that people would experiment to see what was happening. I can imagine a number of things being tried, like someone cutting themselves, breaking stuff, and other very noticeable things to see if it would stay, while some of the more adventurous would try killing someone, perhaps. I think people would generally be pushing the boundaries further and further, until they realized exactly what was happening. Scientists would run experiments, likely looking at the stars and planets to see if they exhibited the same behavior, seeing how far the bubble was. Perhaps they would try other things. Next would come a phase were people would be confused, and wonder why this was happening, and try and stop it from happening. Riots would likely happen in this phase. So would some desperate experiments. Many people would just stop coming in to work. For those things required for normal life to continue, there would likely be some difficulty in getting people there to provide them (Water, power, food, etc). People working stuff that only matters in the long term almost certainly would stop working, as there just wouldn't be any point. Many churches would have higher attendance, especially at first, as people reacting to the drastic change in their lives. Long-term, acceptance would happen. Society would re-structure itself. Likely a new system of time would somehow be created. People would probably come to some kind of an agreement on how to improve life for those around. Those who committed certain types of crimes would be dealt with, so they could not continue to do so. People would try to figure out how to get the most of life. They would likely be concerned about having adventures, seeing and experiencing new things. I suspect that people would take things to the extreme. In fact, I suspect all people would be pushed to the extreme. People would be pushed to be more conservative or liberal in general, further from moderation. Fear of death would not be a real thing. Some people would continue to work just to avoid boredom. [Answer] The first thing that comes to mind for me would be an analogy to [Albert Camus - *The Myth of Sisyphus*](https://en.wikipedia.org/wiki/The_Myth_of_Sisyphus). **One would have a choice as to whether or not to accept the fact that today will be the same as tomorrow.** In the movie, reality was deterministic for the first few awakenings, then Murray's personal growth and new choices changed reality into a less deterministic one. [Answer] I think there would be some big changes, but not the ones most people think. As others have mentioned, this is a post scarcity society. No global warming, no resource limitations. Most people have enough 'money' to buy or do whatever goods they want. But there would be no sellers. So they go to university to learn something, or to a posh restaurant. But there are no staff, everyone is taking the day off because they tried to go skydiving (which was closed, incidentally). However, a new economy would develop, based around the existing services and luxury goods industries. Most other industries would be discontinued. Existing money would have to be replaced. Each person would be required to memorise the net wealth of 3 individuals at the end of the day. A basic algorithm would ensure 3 people memorise each person's wealth (with jail or financial penalties for lying). So while people are not forced to work, plenty of people would (not every day, but when they want more money). Education would become a huge industry. However, it would be a fundamentally unequal society, based on the location you are when things reset. In remote and rural areas, almost nothing would be available, regardless of price. [Answer] > > What of government? What laws will be put in place, if any? Drugs have addictive effects beyond the physical, and there will be great temptation to use. Will the penalties become worse? How can they be enforced? Social programs? Military intervention and distribution programs? What about organizations? The Humane Society, Red Cross, Shriners, Knights of Columbus? How do they remain relevant? Do they? I imagine they will try... > > > First: How do you keep records? In a scenario where everything except for human brains resets each day, how do you write down new laws or contracts for others to study? You might think that you could have people simply remember them, and recite each day, but over the long term that's not going to be viable. The record-keepers will quit eventually. Second: You can't build anything new or permanent. People would have to re-create the infrastructure every single day, and that's not going to happen. Third: there's no point in doing any job. There's enough food lying around to last the day, and you don't need anything new if it'll just be recreated. So losing access to record keeping is going to destroy large-scale governance. Additionally, there's really no economy - why should you care about cash, or gold, if it goes away the next day? Because of these two factors, the only things valuable are: 1. New experiences/education. 2. Protection from hostile actors. So worldwide, society will fragment into two rough groups - conformants and hostile actors. These will organize on a local basis into government analogs, but they will be much more fluid than anything we have today, and smaller. I suspect the largest groups will number in the thousands. **Conformant Groups** will be people who, roughly, want to live their lives as close to normal as possible. They'll group up for protection, traveling a few hours each day to static locations where they can set up a defensive perimeter, and trade knowledge/education/ideas/sex. **Hostile Actors** will be individuals or groups who want to take advantage of others without fair trade. They'll be looking for drugs or sex, since almost everything else is worthless long term. Individuals will probably try to infiltrate conformant groups, although this will be tough since they'd rapidly be found out. Groups would be offensive, looking to capture/assault conformant groups for their use. This will be a fluid situation - a safe spot one day means that a group of hostile actors might try to get their first today. However, I suspect that long-term conformants will massively outnumber hostile actors, because there's simply not much point in going for the rape and pillage thing when there's a reset at the end of the day. So most of the world will be "safe", with islands of hostiles that can't be dug out easily. > > We're also very US/Eurocentric. What about the rest of the world? How will China, North Korea, African nations respond to all this? > > > I suspect eventually almost all of the world will follow the above pattern. You can't keep big governments together, and eventually everyone will fall into localized groups that promote their interests. One thing I do think about most of the rest of the world is that in rural areas, you'd likely see local cults develop around charismatic figures. Without access to first world transportation, these cults would be able to form into hostile actor groups and control/gather all people in their area, basically having permanent slaves. Eventually they'd run into conformants that can defend themselves, though, at which point their expansion would stop. I also wonder if maybe the US/Russia would identify these and eliminate them with the "stop doing bad shit or be nuked" rule, where they have "known" rural cult areas, and watch them with satellites. And if they see the bad behavior, they just launch a nuke, because the long-term negative effects will go away eventually and no one will really be killed. **Conclusion:** This rambled on a fair bit. The main point is it won't be possible to keep large scale governance, so people will organize over time into smaller groups that let them stay protected while doing what they want. Or they'll go for the rape and pillage deal. ]
[Question] [ Yesterday my 7-year-old daughter asked me: > > Why can't I do magic for real? > > > I answered: because of the law of conservation of energy! And I briefly explained this law. Thus she grumbled, "a single law stole so much from us!" This made me wonder about an alternate universe where magic is allowed by physics. What's the minimum set of changes that our local laws of physics would require? **edit:** By "magic", my daughter means any way to obtain a result without **any** effort. For example, she would like to cook an egg by magic, or clean up the room by magic, or transform a stone into a car by magic, and so on. This is why the conservation of energy looked like the most obvious answer: if you find a way to violate that principle in a controlled manner, you can create energy out of nothing and destroy it in a closed system. Then it's just a matter of imagination, and you can create techniques and tools to do anything without any effort (except imagination, but imagination is not a form of physical energy). [Answer] *Tl/Dr: the smallest change isn't one to the laws of physics. It's a small change to the definition of magic.* This is a favorite topic for me. I could talk for hours about it. Not kidding. Find me in chat if you want. There's more magic in the world than we often think! Let's start off slow, with the straight forward physics part of the question. > > > > > > Why I cannot do magic for real? > > > > > > > > > I answered: because of law of conservation of energy! And I briefly > explained this law. > > > Thus she grumbled "a single law stole us so much!" > > > Let's take this one apart. Few people know this, but conservation of energy is actually dug far deeper into the fundamentals of science than it appears. Emmy Noether, in 1915, proved what is now called [Noether's Theorem](https://en.wikipedia.org/wiki/Noether's_theorem). This theorem is so profound that not only is it considered the single greatest addition to mathematical physics by a woman, but may consider it to be the greatest addition to mathematical physics period. Her theorem focused on Lagrangian mechanics, which are systems that are path invariant. For example, it doesn't matter if I roll a rock up a hill, or if I simply lift it up and put it there: the potential energy in the rock is identical in each case. Virtually *all* of modern physics is developed under this assumption. She proved that, if there is a symmetry in the system, there *must* be a corresponding conserved value, because that conservation law will fall right out of the equations. Thus: * If you have time invariance (the laws of physics do not change over time), you **must** have a conservation of energy law. * If you have a translational invariance (the laws of physics are the same everywhere), you **must** have a conservation of momentum law. * If you have a rotational invariance (the laws of physics are the same no matter which way you face), you **must** have a conservation of angular momentum law. So, by this rule, not only would you have to remove the conservation of energy, but you would have to remove the time invariance of the laws of physics. To have "magic" violate the conservation of energy, we need the rules of physics to change every time we cast a spell. *Woof!* Or do we? Noether's theorem works for Lagrangian systems. It doesn't work for other systems, such as those where the path you take matters. What if the path we take does matter? What if the road less traveled *really does* make all the difference? Suddenly we find ourselves in a different environment, where we didn't even need to change the laws of physics to permit magic, just our preconceptions. The challenge with "magic" is that much of what we read in fantasy is so, well, *fantastical* that we develop a definition of magic that is roughly translated as: "magic is the ability to do things you can't do in real life." This is my least favorite definition, and I love encouraging people to shift to another one. This one is a dead end. It always leads to thoughts that start out with "If only I could... but I can't." I prefer the definitions which push at the possible. In this technological world, it's impossible to provide an answer to this question without quoting Arthur C. Clarke's "Any sufficiently advanced technology is indistinguishable from magic." It's such an over-used trope that we often wave our hand and say "yadda yadda, we've heard this before." However, I'd like to draw attention to one little word in that sentence: "indistinguishable." Okay, fine, it's a big word. Six syllables. His definition of magic doesn't include anything about what the magician is doing. It's about what the audience observes. He points out that, while we often like to separate things into nice easy piles using the [law of the excluded middle](https://en.wikipedia.org/wiki/Law_of_excluded_middle), such as "magic" and "not magic," it turns out that for some things, it is *frustratingly* hard to categorize things this way. You really end up needing a third category: "magic," "not magic," and "hmm... maybe magic." I find this third category to be the key to a belief in magic. Let's take the case of [Penn and Teller](http://pennandteller.com/). You've almost certainly heard their names, as two of the most respected illusionists in the magic industry. They've been at it for 45 years, and have seen it all. In fact, they've seen too much. For a few seasons, they hosted a show "Penn and Teller: Fool Us," with the basic premise of inviting lesser known magicians up onto their stage to do magic for them. The goal is for the magician to "fool" Penn and Teller so that they can't tell how it was done. What's fascinating about this is the monologue they give to the audience before the show (and by "they" I mean Penn, of course). He explains that, after 45 years of magic, they've seen it all. They know how all the tricks work. And somewhere, along the way, the magic went away for them, and all that was left was the tricks. So while, obviously, the goal of such a show is to make money, like any show, the private goal for them is to come across just *one* act which fools them so thoroughly that they, for a moment, get to feel the same mirthful feeling of wonder, bubbling up from their gut, that they got from seeing magic when they were five years old. (And, every now and then, [they actually got their wish](https://www.youtube.com/watch?v=CRpz0zuAGVs). *Warning for you and your 7 year old, video does contain curse words, but watching Penn's face just might be worth it*). As you start exploring these things which are indistinguishable from magic, you realize that they show up all over in the our culture. There's something magical about watching the sun rise. It doesn't seem to quite matter that I know it's caused by a $(7.2921150 \pm 0.0000001) ×10^{−5} \text{(rad/s)}$ rotation of the earth with respect to the inertial frame, and [Rayleigh](https://en.wikipedia.org/wiki/Rayleigh_scattering) and [Mie](https://en.wikipedia.org/wiki/Mie_scattering) scattering of photons off of the atmosphere. There's *something* there which isn't quite captured in the scientific jargon, and is different every day, and yet the same. We see it in live music. We see it in the poet's fascination with love. I have a young daughter myself. I was there when she was born. I know the biochemistry. I can explain exactly what happens for the first three divisions of the egg after conception (which is the first point where the male DNA is fully expressed. Some scientists consider *that* to be the moment where it becomes another human being). I can explain exactly which hormones the baby had to emit into my wife's bloodstream to convince her Uterus to let it stick around just a little while longer. I know of that, between stage 28 and 31 of the embryo's eye, it begins a "testing pattern" of sorts, a pattern we literally only see once in our life and never see again, which is responsible for helping sort out the mapping from the optic nerve to the visual cortex. I can tell you that she, as newborn, had roughly 26 billion cells, expelled from my wife's body under the influence of some of the most powerful drugs our body has ever developed. And you know what? Despite all of that, I'll be damned if I'm to distinguish those 26 billion cells from anything but a miracle. Damned I say. When I watch her stare in marvel at a [Gestalt pattern](https://upload.wikimedia.org/wikipedia/commons/6/63/Reification.jpg), trying to make sense of what she sees, she's not the only one staring in marvel. I watch her eye darting back and forth, and truly have to question "How could this *ever* be treated as nothing more than a squishy bag of cells?" To me, that's the state where magic occurs. Not when you *know* something is impossible, but when you're not entirely sure. Is the old lady with a Tarot deck simply reading my biophysical tells and telling me what I want to hear in exchange for my money, or does she really know something that I don't? --- > > By "magic" my daughter means any way to obtain a result without any effort. > For example, she would like to cook an egg by magic, or clean up the room by magic, or transform a stone into a car by magic and so on. > > > "Without any effort" is a hard definition of magic. Many fantasy novels have spells which take a great deal of effort. At the very least, you have to say some words or wave a wand. What does "effort" mean? It [takes](http://www.scientificamerican.com/article/thinking-hard-calories/) 10.8 calories per hour to run the human brain, and its hard to say if it burns any more doing heavy thinking. A child at play burns about 400 calories per hour. Ask your daughter which takes more effort: playing on the playground, or math homework. Some things take very little effort at all, because what we wanted was almost already there. We just had to coax it into being. If there is already an egg, suspended on a string over a pot of boiling water, cooking an egg with a magic wand could take as little effort as waving the wand in a manner which breaks the string, and lets the egg settle into the boiling water. In fact, if she can do this messily enough, there's a good chance a parent will rescue her (and the kitchen), and finish cooking the egg for her! How's that for little effort? The key to such a sense of magic is sensitivity. Sensitivity to everything in the environment around you. If you'll notice, magicians in the fairy tale books often wont cast a spell unless the time is right for it. I certainly wont be casting my egg-cooking spell unless I notice someone has already decided to suspend the egg over a pot. I'm not going to do a "pull a quarter out from behind your ear" trick unless I'm confident I can palm the quarter there in the first place. Is it magic? Well, I know the trick, so it's just an illusion to me. However, if I do that to my daughter, and she smiles, that's magical to me! So if I can do an illusion that she thinks is magic, and she can distort her face into a smile, and I think its magic, how badly do we want to draw the lines between the events. **Can we just say "Me producing a quarter from her ear causing her to smile" is actually magic?** Am I really *forced* to put a line between those two parts, and make the magic go away? Where does this all lead? Anywhere you want, really, but I do think one of the most amazing places it leads is into exploring what your body can *actually* do. It is so much more capable than we think, and its full of magic. For example, you eat food. You can look around with your eyes, process the scene, identify something which contains calories and nutrition, break it up mechanically with your mouth and chemically with your stomach, and extract value with your intestines. Everything I just mentioned is in the upper torso. As far your legs are concerned, the fact that they get calories and nutrients in the blood stream is, well, magical. Now let's put your legs in a position to be magical. Jump (from a reasonably high height) and land on the ground. One of the first real warnings you get that you hit the ground is a strain in the patellar tendon from being stretched by the lower leg reacting to the ground while the upper leg and rest of body continue downward. Sensory nerve signals travel at 80-120mph. That's about a 80ms round trip from the leg, to the brain, and back, ignoring processing time. If you had to take *effort* to resolve this situation, you wouldn't have time to innervate your leg muscles fast enough to catch yourself. In reality, with processing time, the numbers look closer to 200 or 300ms. Instead, the signal takes two paths. One path notifies your brain that something's amiss. The other path goes up your leg, to a ganglia at the bottom of your spinal column. There' it has a monosynaptic link to quadriceps. A monosynaptic link is one where a sensory neuron connects directly to a motor neuron, without any interneurons between to do processing. It's the single fastest link possible in the human nervous system. That link innervates your quadriceps as fast as they possibly can, to catch you. In fact, they are contracting before you are even aware that you hit the ground: This is known as the [Patellar Reflex](https://en.wikipedia.org/wiki/Patellar_reflex), and its what the doctor tests when they bump your knee and your leg twitches: > > This reflex is a reflex of proprioception which helps maintain posture and balance, allowing to keep one's balance **with little effort** or conscious thought. > > > Without even thinking about it, your legs catch you, three to four times faster than you could catch yourself if you expended "effort." Without them "thinking" about it, they are provided with the nutrients and energy needed to make that trick possible. By the way, while the patellar reflex is the best known of these, many other tendons exhibit a similar reflex, such as the ankle and elbow. Every one of these does something you couldn't do with effort if you tried. Do I really have to say that's not "magic?" [Answer] The problem is mostly one of semantics. You can't "do magic for real", because all of the things that you can do for real you consider to not be magic. You can have a conversation with a person on the other side of the world, and if you drop enough money on it you can have dinner with them tomorrow. But those things don't count as "magic", despite being utterly impossible 100 years ago, because we can now do them for real. Magic needn't always violate conservation of energy. So far as the laws of physics are concerned, the energy required to read someone's mind (either for general-purpose telepathy or to work out what card they picked) could be very small indeed, well below what the human metabolism can provide. Producing a rabbit "from nowhere" would require an immense amount of energy, but producing a rabbit from *somewhere* is a problem of transportation. So in some sense, the minimum change to the currently-understood laws of physics to allow magic is *absolutely any change*, or even *none at all*. Whenever we discover something new, or even just invent a new way of arranging ideas we already knew, then something that formerly was as far as we knew "magic" is now "for real". And that's without even getting into the beliefs of those who genuinely think that current scientific theories are fundamentally overlooking certain phenomena that reasonably can be called "magic", or that the definition of "magic" should include things that current science acknowledges do happen for real. Most magic, though, is "things we wish were possible but believe are not". If by "do magic" you mean the power to do *anything you wish*, as opposed to just doing a few new things, then nothing we'd recognise as similar to the laws of physics will allow that. The reason is that laws of physics describe what *must* happen in a given situation (or at any rate what will *very probably* happen), and one can always wish that what actually happens is different from what the laws predict will happen. [Answer] I'd say it entirely depends on what magic means to you. **Something that follows no discernible rules** Example: magic granted by supernatural/godly/other-dimensional beings, who might grant a wish or not, in the way you imagined or not. The beings can't be studied or reasoned with; they act entirely randomly. Well, if you can't study magic in a scientific way because it is unpredictable due to its inherent features, then you might just as well throw all science out of the window. If you know what something behaves like without magic, but cannot tell when magic is influencing it and in which way it influences it, then you might just as well know nothing about it. If magic only happens very rarely, you can stick to all your normal science and just chalk up any deviations to magic. Why can't you do magic for real in this case? Well, you've got no way of knowing where such godly/otherwoldly beings are, and how to convince them to do magic for you. You might just need to try harder and have more luck than winning the lottery 10 times in a row. **Reproduceable magic whose effects violate current laws of physics** If you can measure magic and its influence scientifically, and the results go against what your non-magic science predicts -- well then it's pretty much time to add something to your non-magic science. * some kind of elementary force joining your 4 forces (electricity, gravity, weak and strong nuclear force). Once you learn the rules of this new force, add it into current theory, everything becomes predictable again because you won't be violating the new laws anymore * set up a new theory for an n-dimensional space instead of our regular 3D+time space. Properties of those invisible dimensions might result in things that might seem like magic to us, but are entirely explainable. Example: imagine not knowing that the earth is round. You think the earth is a flat plane, and you want to discover where this plane ends. You walk in a straight line for ages, sail the seas in a straight line, walk some more -- just to realize that by some inexplicable magic you eventually arrived again where you started out. You must have encountered a fearful daemon to have your way deviated back to your beginning, indeed! * It might even require trying to quantify something like 'soul', 'will', 'determination', etc. Whichever it is -- you will need to add something to current physics to get to a once again comprehensive physical world model. (this one interpretation of the famous Arthur C.Clarke quote of "Sufficiently advanced technology might seem like magic") Why you can't do magic for real in this case? Well, do you know what it is you are supposed to be doing, i.e. what the magic looks like? And, would it still be magic if it's just a strange part of science we haven't discovered yet? **New applications for current physical laws** The primary interpretation of Arthur C.Clarke's quote "Sufficiently advanced technology is magic". Imagine Thomas Edison, who invented the light bulb. Yes, he knew what electricity was, what a phone was, and I'm pretty sure he also knew about wireless transmission. Would he think the abilities of an old-fashioned mobile phone magical? Perhaps. A smartphone? I sure bet he would. And that's only what we've done with science in the last 150 years. All in all, you must never forget -- science is not set in stone. First comes the theory to explain observations (all apples I have ever seen fall downward). Eventually, if the theory has been sufficiently verified (not only I have seen apples fall downward, but my family too and my neighbors and my professors and people on the other side of the globe), it becomes a law (all apples fall down and not up). And only then can it be used to predict things that haven't happened yet (when I let go of the apple in my hand, it will fall downward). However, the first time an apple floats upward, it requires a really hard look at current laws and the circumstances under which the apple fell upwards (I was hanging upside-down from a tree -- in my perspective, the apple went from my toes to my head instead of the other way round). So, there is plenty of ways of finding 'magic' even within our current physical laws :). And of course, you can do 'magic' by studying science and trying to come up with new, revolutionary ways of using it! [Answer] You might point out to her that she already does magic. Tell her to turn on a light. Can she explain how she did that? Have her turn on the TV, and explain to you how she can bring up images of people (even dead people, if she likes reruns) who talk to her. Get a copy of Dragon speech recognition software and install it on your computer, then ask her how something can respond to her voice. At seven, she's probably too young to have experience firing a gun [![enter image description here](https://i.stack.imgur.com/amONJ.jpg)](https://i.stack.imgur.com/amONJ.jpg) but she's surely familiar with the idea. Ask her how pulling a trigger is different from throwing a lightning bolt. The answer, of course, is that she's used to doing everyday things, and doesn't think about them, but the things she can't do are magic. It's like with artificial intelligence: "If we know how to make a computer do it, it's not AI." As Paul Simon put it, "These are the days of miracle and wonder". Magic, in general, has effects without physical causes. Depending on what stories you read, it is either accomplished by calling on supernatural beings or simply by the exercise of will, just as we move our fingers simply by wanting to. Wishing makes it so. Trying to tell a seven-year-old that this just doesn't seem to work outside of stories is a pretty hard sell - children fundamentally believe in magic. As for your literal question, the answer is that no set of changes in physics will allow magic to work. Conservation laws simply don't count, since you can simply assert that any unaccounted-for energy required is provided by magical transmutation, including fusion. (Because it's magical, there are no radiation side effects.) The big problem with making magic scientifically usable is that it destroys science. That is, no experiment can be trusted: its outcome may be altered by magical means. With no experiments which can be trusted, the cornerstone of scientific endeavor, Poppert's falsifiability, becomes impossible. [Answer] # None Magic is possible, as soon as we find a way to tab into a source of unlimited energy. The point is that just because we didn't discover that source yet, does not mean it does not exist. But, after you found it, this will happen: > > Any sufficiently analyzed magic is indistinguishable from science. > > > ([Agatha Heterodyne](http://www.girlgeniusonline.com/comic.php?date=20081205)) Of course, to get the "make a wish `->` see it happen" kind of magic to work, you "just" have to make cause and effect stop working at the place you are at and wait for the random chaos to be in the shape you want it to. [Answer] Everything, or nothing. You've noted the law of conservation of energy. Well, this isn't the only reason. Suppose you want to conjure up matter as your magic trick. The law of conservation of mass applies, obviously, unless you're taking it from somewhere else, which would violate the universal speed limit. But there's more to it. Something has to happen to the air that used to be in the space your conjured object now occupies. Conservation of mass applies, after all. This has to happen before the new object can occupy this space. Why would it? You'll need to make alterations to fluid dynamics. The short of it is, if you're going to change physics, you have to change it all because it's all so related. Maybe I've decided I want kinetic energy to be $K = mv$ instead of $K = \frac{1}{2}mv^2$. Well, $W = \int F \cdot dx = m \int a \cdot dx$. Now we're talking about the basic $F = ma$ formula that physics is built on. If you're gonna change that, the whole universe is now entirely different. But on the other hand, maybe there's a way you can make all this stuff work without actually changing any laws of physics. Though if so, stop talking about it on worldbuilding.se and go patent the ever-loving crap out of it. [Answer] > > This made me wonder of an alternative universe where magic is allowed > by physics. What's the minimum set of changes that our local physics > laws would require? > > > The laws of physics require that if magic exists then *they* don't. The minimum change to physics that would allow *real* magic is the nonexistence of physics. All science depends on the expectation that the universe operates by regular cause and effect. If the laws of physics are no longer laws, just guidelines, then the ground is cut from under the feet of the whole idea of physics. That is not to say that our understanding of the laws is necessarily complete. Perhaps someone could cause things to happen by willing them in some manner that is functionally equivalent to magic but actually is within the wider laws of physics, if we but knew them. That is not to say that the physical constants such as the speed of light, or rules like the conservation of mass-energy, that we think of as applying everywhere necessarily do. That is not to say that what we think of as "the universe" actually is all of the universe. That is not to say that there cannot be a God who created the physical universe and its laws, or intervenes therein. That said, if anyone can think of some nifty physics workarounds to explain apparently magical doings, don't be shy, because it would really help with the story I'm stuck on. [Answer] Well, technically speaking, there's nothing wrong with our world. Magic and miracles are just manifestations of power which humans aren't able to do. But in itself, magic isn't opposed to science. It's just too difficult for us humans (well, some kinds of magic are illogical, but that's not the point here). **The changes required are *for us to be more powerful***. As for how much more, it all depends on what you want to do. For exemple, invisibility would be possible if we naturally did [these kinds of things](https://en.wikipedia.org/wiki/Invisibility) which already aren't fiction anymore. (tell me if you have a better link) So it is more about us than about the world we live in. [Answer] Since most magic *as described* violates various conservation laws, or the laws of thermodynamics, it is by definition impossible. However, since we want to go from *impossible* to at least *improbable* the best thing to do is look at quantum mechanics and see how to change probability. We "know" that Space-Time is a seething flux of energies and matter, with particle-antiparticle virtual pairs appearing and disappearing all the time at the Planck scale(no one has actually "seen" this, but we can infer this from effects in the visible universe, and it allows us to make mathematical calculations to describe what is happening). While we really don't understand this very well (the supposed energy in a volume the size of a coffee cup could theoretically boil the oceans of Earth, yet there are no visible effects due to gravitational lensing on the scale of the Universe), gaining the ability to tap into this source of energy, or dump energy back into this as some sort of heat sink would allow you to do serious magical activity without violating thermodynamic laws (you are simply transferring energy and matter to and from a vastly larger pool, and using different timescales to manifest the effects). Quantum mechanics also postulates that things and effects are due to the "collapse" of wave functions due to the activities of an observer. The Schrödinger's cat thought experiment is a good example of how this effect is supposed to work [![Schrödinger's cat](https://i.stack.imgur.com/xfrTm.png)](https://i.stack.imgur.com/xfrTm.png) Getting a rabbit out of a hat then becomes a matter of arranging for an observer to collapse a wave function where a rabbit is *already in the hat*. Since the probability of a particular rabbit being in a particular hat at a particular time is a known function (or at least calculable in principle), then a sufficiently trained observer should theoretically be able to "find" the probability of a rabbit being in the hat, reach in and grab the rabbit out of the infinite possibilities of rabbits/not rabbits/ alligators/ other things being or not being in the hat. Obviously this will require a lot of care and attention..... Of course the less "probable" the effect you want (walking through a wall, for example) the more difficult it will be to do. This degree of difficulty, coupled with the amount of computational power and focus needed to "find" and "observe" the magical effect desired explains why magic traditionally has been in the realm of the gods and a very select body of wizards. (Read Lord of the Rings or Le Mort d'Arthur very carefully to see just how little actual "magic" Gandalf or Merlyn do. Remember in LOTR, Gandalf is actually the equivalent of an *angelic being* to keep it in context). [![Gandalf](https://i.stack.imgur.com/JB3Hr.jpg)](https://i.stack.imgur.com/JB3Hr.jpg) I find blowing smoke rings far easier and more relaxing.... [Answer] The smallest change to the expression of the laws of physics that allows magic would be something along the lines of "The laws of physics are <real laws of physics>, except that, when I say 'abracadabra' whatever I say next will happen." [Answer] > > imagination is not a form of physical energy > > > I believe the answer is predicated on dispelling this false assumption. Imagination is a function of the human brain, which uses electrical and chemical signals to produce conscious thought as well as control involuntary processes. > > It is well established that the brain uses more energy than any other human organ, accounting for up to 20 percent of the body's total haul. <http://www.scientificamerican.com/article/why-does-the-brain-need-s/> > > > So, while it may not be a 1:1 correlation (thinking hard has been found to cause only a minor increase in calories burned as per <http://www.scientificamerican.com/article/thinking-hard-calories/> which alludes to the fact that perhaps the most complicated tasks our brains do have nothing to do with conscience thought at all), imagination DOES indeed require energy. There is nothing that says that physics and magic have to be mutually exclusive, and, in basically all popular fantasy novels and games, magic is something that doesn't just happen and also seems to follow some predefined laws. Fantasy games generally use the concept of some arbitrary energy unit that is consumed when a spell is cast (otherwise the player would simply cast the most devastating spell over and over until the game was over). In LOTR, why didn't Gandalf just transform the opposing army into firewood or rutabagas using a word? In my opinion it would have made a VERY uninteresting book. It seems that even imaginary universes can't exist without laws, because without laws no one would care about them and they would cease to be (being imaginary and all). Considering the possibility of alternate universes with different physical laws where a being COULD simply make something happen with no expediture of energy, that universe probably ceased to exist because one of these beings thought it should cease to exist (bad case of the "Mondays"). In a universe like ours, that scenario is prevented by the fact that too much energy would be required to convert all the remaining matter in the universe into energy. If we impart some rules on magic, suddenly it doesn't look so daunting. What is lacking is OUR human ability. We don't need to change laws. We need to evolve. If we could evolve a way to generate an ultra-powerful magnetic field (why not? eels can generate electricity) or lasers (advanced bioluminescense), then why couldn't we channel that ability to convert photons into matter (<http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_16-5-2014-15-32-44>)? With enough ability, why couldn't we arrange that matter in any way we want? After all, "stuff" is just a bunch of atoms arranged in particular ways. With enough metabolism to back the activity, why couldn't we arrange freely available sunlight into a pizza? That sounds a lot like magic AND science to me. Now, since it wouldn't be a lossless conversion, you couldn't infinitely make pizzas from sunlight and energy gained by eating the pizzas, so you would need an external energy input, but I am pretty sure that the wizards in games and books have external energy sources too (potions, food). It all works out. And that being said, go back to the electric eel for a second. I believe it meets the definition of magic (produces electricity capable of killing a human via cell vibrations simply by "thinking" about it). We've explained how it works, making it science, but as soon as we explain exactly how ANY magic works, THAT will become science too. Being a magician might be just like being a computer programmer... a skill you learn using your mind and body. The programmer arranges code and types it with his fingers. The magician architects matter structures and arranges them with his hand, or wand, or staff, or whatever. So, tell your daughter the truth... magic is absolutely possible AND it is real, but has some rules (because without these rules, it wouldn't have the opportunity to exist). The magic we see in movies isn't "real" magic because movies and books have a REALLY bad habit of NOT considering rules (ever watch the cops in most cop shows? They'd all be in jail...). Then head off to the aquarium or science museum and see some in action. Eels turn food into energy into motion back into energy. We turn food and light into electrical and chemical impulses which we interpret as thought, which we then turn into a painting, converting that thought into a physical thing with brush that looks a lot like that instance of light we originally saw reflecting off the object we painted. We might not be able to turn a rock into a new bicycle (well, we can, but it is a long process involving first extracting the iron and so on), but neither could Gandalf turn Orcs to rutabagas. Therein lies another lesson for a child... even the most powerful and amazing forces follow rules. [Answer] Providing that something is "magic" depending on personal background (in example a country-side may look "magic"), if few humans were able to manipulate mind and cause allucinations to someone else, than the person subject to allucinations may as well live a whole life believing to see real magic, so in a certain sense he will "have magic" without even the need to change a physical law. However, you are asking specifically for a change of a physical law. The fact that we are in practice out of control on nature is basically the "lack of magic". To have magic we need to have control on nature, the simplest thing came to my mind is Entropy, **Entropy** can only increase: * If we have a box with air particles randomly travelling inside the box in practice it never happens that the particles will be ALL on the same side of the box. If people can be in someway able to control phenomenas that actually look random, we can start getting amazing things! (so give the ability to reduce Entropy.. in some way) In example, air particles could randomly hit a body only from one side, effectively helping making the body levitate in thin air. Of course we are still respecting energy conservation (after a particle hit the body and the body moves, the particle lose energy and get cooler). We are currently 4 dimensional beings (at least) because we move forward in time and we have a volume, being able to choose a immediate near future where to live (in example the future where all air particles hit a body from below at same time) may make us 4.1 dimensional beings and could explain the ability to influence our surroundings. In such world the magic would still be limited by other natural laws, and understanding we have of other natural laws gives us more control (we know better immediate futures where we can walk). A strong mage may know that items have thermal energy, so he can levitate objects that are in void (with the constraint that those objects will become cooler). Freezing someone would be indeed a possible magic in such world. Of course there will not be any counter magic, every mage simply wins (from his personal point of view), because every mage go in his immediate future. I'm still not sure how that will affect a civilization. There will be a explosion of divergin futures (right now I don't believe our universe would be much "divergin") [Answer] I think you need to define 'magic' first. What would seem magical to a child of 7 might not seem so to a physics professor or an engineer. If you'd told an educated 17th-century European that he could see someone on the other side of the world this morning, talk to him, hear him, as if he were in the same room - that might indeed seem magical to him. Then to clinch it, tell him he and this other man could have breakfast together in the same room, at the same table, passing food back and forth to each other. That would seem beyond magical. But to your daughter? Ho hum. So what would she call magical? Probably the ability to be in more than one place at the same time would be the most impressive. Then the ability to know the future in precise detail. Those two are about as magical as you can get. For the first, you'd need to be able to violate the conservation of matter and energy. For the second, you'd also have to violate the laws of entropy. When you violate these, you've trampled over the law of cause and effect, and then nothing at all remains of physics. Which goes to show that if you abandon the smallest part of physics, you lose all of it. I am not saying that we know or understand all of physics, but we have reached a stage where we can say that what we have may be incomplete, but it's an integrated, unified structure with no spare parts to jettison. So you and your daughter have to accept - it's physics or magic, but not both, and you'd better both hope it's physics. [Answer] Let's take the most well-known alternative universe which involves magic: Harry Potter. What do people in Harry Potter do that we, as Muggles, can't do in the real world? * We can't channel energy as spells through wands from our bodies * We can't make potions as described in the universe(but some of them we could, if science advances enough) * We can't teleport(Apparate) or use Floo Networks or Portkeys. * We can't make other objects move telekinetically or change their physical characteristics directly(we can through irradiation, but let's leave that out). * We can't make things out of nothing * We don't have things that have different sizes from the inside and outside. * We can't predict the future * We can't talk to ghosts * We can't transform into animals * We can't animate otherwise lifeless objects(such as statues or Inferi). * We don't have animals that breathe fire or anything similar Some of these things can be changed by manipulating Nature, some can't. Let's analyse them one by one. **We can't channel energy as spells through wands from our bodies** This can simply be achieved by violating the law of conservation of energy, as you suggest. Then we'll be able to yield infinite energy without any being taken away from the body. We could also make it any form we wanted, leading to different kind of spells(not all, though). **We can't make potions as described in the universe(but some of them we could, if science advances enough)** Well, in our world, medicines are a kind of potion. In that sense, we can make potions, but not most of them, like the Polyjuice Potion. I'm doubtful if some could be made at all, like the potion which makes pictures move, 'cause that's not how pictures work. **We can't teleport(Apparate) or use Floo Networks or Portkeys.** This'll also require the violation of the law of conservation of mass-energy, or the attempted teleportation of a single person will destroy all life on earth, as the only way to really "teleport" is to convert oneself purely to energy and back into being at the destination. We can use some types of Floo networks(faxes and the Internet come to mind), but they're no match for really being able to send people though. Wormholes, if made possible, would also be a type of apparition, as the feeling described in the books could be similar to the one of travelling through a wormhole. **We can't make other objects move telekinetically or change their physical characteristics directly** Here I'm talking about the chess set and Transfiguration. Transfiguration will also require conversion to pure energy and back, or somehow being able to split any element to hydrogen and recombine to needed element. I'm not sure how you'd breathe life into the 'raised' object though. **We can't make things out of nothing** I'm not really sure how this one works, but your theory of the law of conservation of energy should come here too I suppose. **We don't have things that have different sizes from the inside and outside** We'll have to change the law of conservation of space - effectively allowing fitting a 787 Dreamliner jet inside a courier carton. **We can't predict the future** This'd require time travel. Perhaps someday we'll evolve into 4D or 5D beings or something and then this one will come in, but until then, no future predictions for you(reliable ones, at least). **We can't talk to ghosts** A ghost is just a lone soul, without a body. Can't blame Nature here. The concept of a soul is not natural; life is just the effect of thousands of chemical processes happening in sync inside living things - they stop, the soul's gone. So we could make a crude comparison to a radio that's on as alive and one that's off as lifeless. Basically nothing physics can really do here, it's not involved. **We can't transform into animals** This one's similar to the fourth or fifth one. Undefined behavior on recombination. **We can't animate otherwise lifeless objects** We do have a variant of this one already - robots. But they are 'alive' for a reason similar to the seventh one - a series of processes that make it possible. I'm not really sure, but my best guess here would be 'everything about the way living things work will need to change'. **We don't have animals that breathe fire or anything similar** This is similar to the first - we'll need to break the law of conservation of mass-energy. Any animals alive in the world simply can't absorb energy from their surroundings fast enough to project it out at that rate. And living things are carbon-based, which means breathing fire will burn them up from the inside. So I guess life will have to exist as non-carbon based - iron as a candidate, anyone? So I'll second what some others have said: depends on your definition of magic - but I don't think any single law will be enough - our world is too different and too complicated. [Answer] **Laws of physic are just an old habit** There are already quite inspiring answers here. I just want to point out something not outlined so far. We are used to see the laws of physic as stable and everlasting, they have ever been, they will ever be, they will never change. *We only believe that. We have no evidence.* When where these laws born? Have they already been before the universe was born? Are they a fixed part of our universe and could never have been different from what they are now? That is implausible. A least, we already know that our universe is not mechanic, but has an unforseeable base of events in the smallest known parts of matter, not following the used thoughts of cause->impact. Think of this possibility: As the universe was born in a big bang, there have been no laws of physic. Matter and energy was something completly new, and nothing and no one told them how they should behave. But they happened to *be*. And they interacted with each other and got used to behave in new ways that never have been defined. As time goes by, this used-to-behave become a habit, this habit established over some X\*1.000.000.000 years. These habits are what we see as stable laws with obviously (?) no exception. (Compare this book: *Rupert Sheldrake: Morphic Resonance - The Nature of Formative Causation*) You know, habits have their own power, and it is difficult to diverge from them after getting older than xy years. What about the universe? It is quite old, yeah. You don't need to change the laws of physic. It is enough to persuade the universe to deviate from its habits a bit. Nothing needs to break. It is always possible that something quite improbable happens. The magician knows how to summon the universe to do something really crazy. Little daughters do crazy things, too, not foreseen by adults. [Answer] A magic wand is simply a Star Trek transporter combined with a replicator and miniaturized. Of course, voice activation/recognition is simple for a race this advanced. When not speaking the wand uses telepathy to communicate with the wizard - of course most wizards need to sync their brain waves with the wand, which is why Harry Potter and the rest had so much trouble using it. It took years of practice and schooling. The wand does not violate any sort of physical rules, as it absorbs matter from the air, ground, or whatever is handy and converts it to energy and back again. You probably couldn't re-animate anyone, but even today using CPR we can revive someone who has been dead a few minutes. By replicating nano-bots you could form a swarm of them into any shape and have them move around and do stuff. They could even seem like ghosts, by simply changing their color,arrangement, and density. Using a proper containment field, it could even store energy/matter in a micro blackhole inside the wand. [Answer] > > By "magic" my daughter means any way to obtain a result without any > effort. For example, she would like to cook an egg by magic, or clean > up the room by magic, or transform a stone into a car by magic and so > on. > > > The first two are easy. They've been available for millennia. You tell a servant to do it. Transforming a stone into a car is more difficult. (I suspect the OP added that themselves ;-) A rich person could order a car and get someone to wait round the corner with it. They then tell the child to close their eyes. Hide the stone and the car appears. > > This is why the conservation of energy looked like the most obvious > answer: if you find a way to violate that principle in a controlled > way, you are able to create energy out of nothing and destroy it in a > closed system. > > > Who says it's a closed system? The planet Earth isn't a closed system. We continually get energy from the sun. Maybe the sun outputs mana, we just haven't detected it yet. In the far future who knows what's possible? You simply can't specify a local closed system as a counter-argument to magic. [Answer] As others have said, it partly depends on what one means by 'magic'. Here's my two cents: **Magic is the capacity for people to make things happen in the world immediately through acts of speech *(or gestures, which can be construed as a means of speech ['sign language'])*.** I.e 'wishing makes it so'. This used to be impossible given known physics, but not anymore - or haven't you heard of **Siri**? More generally, our continuing expansion of the things we can do with computers and programming *(e.g 'the Internet of Things')* can - and in my opinion maybe *should* - be construed as laying the infrastructure for a future in which practical magic actually exists. [Answer] Magic is real. The only reason your daughter - or most other people for that matter - can't do it is because some well financed evil wizard and his army of rainbow vampires is draining all the mana from the mabric. Getting only a pixel of the mana that's left takes a lot of meditation, fingerpainting, hugging, a healthy diet, singing and other rituals. Patience and will are both fruit and fuel in this endeavor. It's basically a matter of opening the eye. Also trippin'...' [Answer] The Standard Model of particle physics has different composite theories, such as electrodyamics and chromodynamics (EM and strong nuclear forces, respectively). I recently went to a physics talk where the presenter proposed another composite theory based on combinations of different particles and their interactions. A composite theory could add another "force" depending on how it dictates interactions. A new boson, such as is suggested by the LHC, could provide support for a new, artificial force. In short, a new force, artificial or otherwise, may be your answer. [Answer] Cort Ammon wrote: > > If you have time invariance (the laws of physics do not change over > time), you must have a conservation of energy law. > > > OK, posit then that time invariance gets broken -- the laws of physics *did* change -- the Old Gods woke up, and they're not (for instance) great believers in all that bookkeeping nonsense in Thermodynamics; it cramps their style. And those big, sudden entropy/enthalpy changes look (to the survivors) indistinguishable from magic. [Answer] **Our laws of physics are just as good as any other, or just as bad as any other for magic** (this answer is unfortunately a response to the many other answers here) There is one simple reason we can't do magic, because **if we could do it, it would not be magic**. If we lived in a world without the conservation of energy, we would be just as bored as we are now. What makes magic fun in fiction is that the characters do mundane things like say words, and get special effect. In any world used to that set of rules it would not be fun, it would be boring work. If fact we do not live in a world that conserves energy any more or less than a common magical world. Most magical worlds have power sources, and ours is no different. Our most common power source is the sun. It constantly provides us with new energy external to our system, no different than channeling spirits, or drawing mana is in any magic setting. We can also imagine people living in a world without electromagnetism thinking about how magical we are to be able to move objects at a distance with magnets, and make lightbulbs glow. As for doing something without **any** effort, that is also a logical flaw. **No one in fiction uses zero effort.** There is always a wave of the hand, a magic word or at least a thought. Are voice operated systems magic? We always need a way to explain intent otherwise the events would just be random and not magical at all. What about magic that does things before you ask? Is Google telling you about traffic without you even asking magic? So magic and supernatural can only exist in fiction because that is what the words mean. If we don't have an energy issue any more than any other magic world, and we can give commands to things our world is just as fit as any other for magic. We simply need to push our tech level to achieve the ease of use for whatever your definition of magic is [Answer] # Without overthinking this the answer is derived simply by definitions of the problem Reading answers pretty carefully I haven't seen anyone directly go into the definitions of physics or magic for their responses. And so this answer grabs a dictionary and answers the question objectively. ## Physics is a science first; science is a philosophy. Physics is an accepted philosophy about what effects occur with a given cause. I'll refer to Oxford's definition which lumps the sciences (philosophies) into mechanics, heat, light and other radiation, sound, electricity, magnetism, and the structure of atoms. ### Diving deeper: **Science here refers only to the natural sciences.** While many people including scientists bow down to natural sciences as a surrogate for God and grant it omnipotent power over all things known and knowable, science itself just shrugs and reminds us that it is indeed a box with walls, and some things are very much outside of its box. I.e., (Natural) Science is not just magic with a funny spelling as every science fiction story will tell you. The box of stuff that natural science can work with is exactly defined. Anything you can observe or have observed that doesn't fit inside this definition, can't even be looked at by anyone practicing the natural sciences. It's outside of the box that science drew for itself. This definition, has been elusive, but has some fundamental commonalities. ### WILLIAM T. RICHARDS, PRINCETON UNIVERSITY, NEW JERSEY, 1928 > > “Almost every man of science since the time of Aristotle has tried his hand at defining his profession, and a continuation Of this practice must without the least hope of originality…. ***Science is the systematic description of phenomena.***” > > > > > “**Phenomena**," with its implication of **reproducibility** and of **common experience**, separates the physical sciences alike from the arts, and from some aspects of the psychical. Again, the word "**description**" patently suggests the necessity of a **language for the expression of scientific generalizations**; the language employed is conditioned by the nature and degree of development of each branch of science, **mathematical statement being**, of **the common medium of the physical sciences**. Finally, the qualifying adjective "**systematic**" serves to **distinguish scientific statement from merely casual**, if empirically substantiated, expression of experience. > > > Therefore, when your question asks to change physics, you are asking for a world where *phenomena cannot be systematically described*. That is all that is needed to allow observations which would qualify as magic, or, more literally, "supernatural" which exactly means "situated or placed above natural." A supernatural phenomena is, therefore, a phenomena which defies any of the qualifiers of a natural phenomena. **The philosophy that suggest all known and unknown observations do and forever will obey natural laws** is a dogmatic religion called scientism. It is irrational. It's premises do not vest in reason or fact, are purely axiomatic assumption about unknowns, and are antithetical to scientific progress. But it has a purpose. When we approach a phenomenon with the scientific philosophy, there can be no assumption except that the phenomenon can be "systematically described." It is absolutely imperative to observe that this is an ASSUMPTION, and without that assumption, you simply cannot put your observed phenomenon into the natural science box. If you even consider that your observed phenomenon was, for example, the product of a druidic curse; then none of your scientific tools will do you any good. Your problems will manifest everywhere at once, but specifically; you will NEVER be able to reproduce the curse, and therefore you will never be able to use the word "systematically" to describe it. The phenomenon certainly can still be studied, but never with that supernatural assumption. Your assumption MUST be that the phenomenon, no matter how bizarre, is a reproducible, common experience, that can be described mathematically. ## The following assumption is untrue about natural science: **if we could do it, it would not be magic** Because of the box William T. Richard and many others have drawn around science, "reproducible" is not the one and only part of the definition. But now that we have a good definition of science, phenomena, and physics, let us explore breaking it by going into definitions of supernatural phenomena, which are all currently allowed by physics. ## Miracles A miracle is very simply any phenomena that can not be reproduced. It is a one-off event that nature can't ever do again under any circumstances. Physics allows miracles as it currently exists. Miracles are outside of the box of things physics can even look at, because they CAN NOT be reproduced; therefore they CAN NOT be studied. An example of such a phenomenon is the apparition at Fatima, Portugal on October 13, 1917. This event was witnessed by thousands of people, including children, and was extensively documented through photographs, eyewitness accounts, and official church investigations. The apparition at Fatima is a phenomenon (check), with common experience (check), however it cannot be reproduced, and it can not be systematically described. Therefore, neither physics nor science in general can *deny* the apparition at Fatima, the phenomenon was also not provable as a natural event. Thus, physics currently does allow apparitions such as those documented around the world by photographs and accounts. Physics will never (and can never) *describe* this miracle, or any other, because miracles are not in the box. Other miracles that work fine with modern physics include walking on water, parting seas, raising dead, multiplying food, healing blindness or cancer or heart disease, and crumbling city walls with a song. Physics will certainly say that it can't happen again, but it can never declare that a well documented and commonly observed phenomenon *didn't* happen since it can't reproduce the effect. ## Spells Spells are a very tricky thing to escape the physical box because they claim to be reproducible. That reproducibility puts the phenomenon of a spell they produce squarely inside the box of stuff science can look at. In order to allow spell with the current definition of science, you either have to deny common observation (as we see with the observer effect in quantum mechanics), or you have to deny a systematic description of it (as we see with the spontaneous event called radioactive decay). There is no possible way to describe the phenomenon of an atom of Carbon 14, for example, decaying into a Nitrogen-14 and an electron. We will never have a mathematical description of when that event will happen, because it has no cause. It is by definition, a spontaneous event. Another such spontaneous event is wavefunction collapse of a quantum entangled particle. So those real-world examples form the basis for allowing a spell: reproducible magic. Physics currently allows such things because we know about the quantum weirdness and radioactive decay, but we can describe them mathematically, so they are still inside the box of science. In order to take a spell outside the box of science, and put it into the supernatural, you have to remove the mathematical description. In other words, the effect your spell creates has to be reproducible, but not have any mathematical description. This is not terribly hard to do since math relies unequivocally on the equality sign. You can not describe *anything* with math when the right side and the left side are not equivalent. This is the foundation of all laws of conservation. An example: Since the question asks for the "minimum change," I will use an atomic-sized violation. Let's assume that when you snap your fingers (and you alone, no one else can do it), that then next time a Carbon-14 atom decays under your microscope, an electron flies off, but the Carbon-14 is still Carbon-14, and not Nitrogen-14. Here you have created a spell which very simply masks the aging of something, so that science will plainly see the beta emissions and count them, and they will THINK that the sample is X years old; but in fact, the carbon is not actually diminishing. You have created electrons from nothing. This little spell would effectively be a fun wizard college prank or cantrip, bacause you are creating something (an electron) from nothing, violating the law of conservation of matter and energy. What this trick could do is hide a stash of barley in an old jar, then ask your friends to enjoy some homebrew beer using your "fresh" barley 1,000 years later (you're a wizard, remember), and tell them with a shocked look on your face when the dusty ancient crumbs pour out that you "just packed that barley last week! What possibly happened? We must get this to the lab!" They will find week-old barley dust, and great fun will ensue in the journals and universities across the globe. ## Elixir of Life Again by breaking the equality sign, you can reverse the processes of entropy operating on your DNA as each cell undergoes mitosis. It requires only a tiny fraction of energy to override the energies which find their way into your DNA while it is unwinding and recombining. This DNA protection scheme is outside the box of physics despite being a repeatable and commonly observable phenomenon, because again it creates a small amount of energy from nothing, defying a mathematical definition. Every cell in your body repeats it so long as the potion is in your bloodstream, but the source of the repairs defy math. Modern science would fail to classify this as "natural" despite its repeatability. The Elixir of Life does not need any changes in physics to exist, it is already defined outside of science, and so can live harmoniously with the laws of physics as they are. And so long as the elixir itself can not be manufactured, there can be no argument saying "physics is broken." They can't repeat the Elixir; therefore physics is just fine. Physicists will be loosing many nights of sleep, but physics itself has no problem with an inability to put it into the box. It just ignores those things. # The smallest change to physics needed to allow magic is any arbitrary amount of inequality measured in any commonly observed and repeatable phenomenon. Either something from nothing, or nothing from something. ]
[Question] [ My hero lived his ordinary life until recently, when he realized that Magic actually exists. So far, he has been granted levitation for a short period, and invisibility for several hours. Both worked perfectly fine. Now, he has received a third gift from a magician. Immortality. My hero was told, that the immortality works like this: * The only thing that can actually kill you is getting your head cut off completely or starving to death. * Other injuries will still hurt, but everything else will recover itself without the need for surgery. * To recover, your body will need extra energy to heal. So if you are hurt, you have to eat and drink like crazy. * The immortality works on the principle of "quick, flawless regeneration". Each cell in your body is regenerated perfectly without any pesky side effects, aging included. * You cannot drown or suffocate. However, your body will need extra energy to work underwater or in unbreathable gasses. * Extra objects inserted into your body (like bullets or daggers) will eventually be absorbed by your body. And yes, that's extra energy cost. * You cannot get fat. If you overeat, your body temperature will increase to get rid of the excess energy. * The magician will check your progress in life after 250 years. As you can guess, the magician disappeared after telling my hero these basics. My hero is a 30-year-old male who has never had any type of operation which leaves something in the body (like hip replacement or a bone fracture, which needs screws to hold the bone together). He tried to cut himself, and it hurt as usual. The scar seems to be healing quicker than my hero is used to. My hero still does not believe in magic. Also, he does not trust this magician. However, if he is really immortal, he can make some long term plans. So, how to test if you are immortal? Yes, you can put a dagger to your heart ... but if the magician was lying (or immortality does not exist) that would be a really stupid test. Edit: This is happening in current world, current time, in one of First-World [Second-World](https://en.wikipedia.org/wiki/Second_World) countries. Apparently, [Czech Republic](https://en.wikipedia.org/wiki/Czech_Republic) seems to be still on the list of Second World countries... [Answer] # Start with the simple stuff Well, you have written a list of rules and most of them are non-fatal if tested. So you can start with the simple and "safe" stuff, and then move down the list. ## Objects are absorbed I have a slight objection to that one: absorbed as in **encased and kept indefinitely** or **dissolved and excreted**? Test: **Push a sewing needle into your arm**. Success: Needle is gone after some amount of time. Failure: Needle causes discomfort, infection, inflammation or otherwise hurt you. Keeping safe from failure: Visit a doctor and have the needle extracted. ## Cannot drown Test: **Jump into a pool** at the shallow end and crouch down. Bring a buddy if you wish for extra safety. Success: Still alive after 10 minutes with no ill effects. Failure: Feeling the usual feelings of panic and discomfort of not being able to breathe. Starting to get grey-out and tunnel vision. Keeping safe from failure: Stand up and breathe. ## Cannot get fat Test: **Eat excessively**. Monitor your body temperature Success: You do not get fat. Body temperature rises. Failure: You gain weight. Keeping safe from failure: Stop over-eating. ## Fast healing 1 Test: **injure yourself lightly**. See how long it takes to heal and if that varies depending on how much you eat. Success: Wounds heal without scarring or discoloration, and they do so depending on your food intake. Failure: Scarring results. Wound do not heal any faster compared to what they would normally. Keeping safe from failure: Stop injuring yourself ## Fast healing 2 Test: **Cut off some part of yourself**, like a centimeter wide flap of skin, as if say removing a birthmark or a mole. That cannot heal on a normal person without scarring. Success: The cut is healed without scarring. Failure: The cut is not healed without scarring. Keeping safe from failure: Sorry, you will have to put up with that scar. ## Fast healing 3 Test: **Donate blood** five days in a row. No normal person reacts well to losing five pints of blood in that short amount of time. Success: You do not experience dizziness or other signs of low blood pressure. Failure: You start to feel the symptoms of blood loss. Keeping safe from failure: Stop donating blood as soon as you feel the least bit ill. ## Fast healing 4 Test: **Cut off the tip of a finger** Success: The finger heals without trace of injury Failure: The fingertip does not regenerate Keeping safe from failure: Again, sorry, it is gone... but a fingertip is easy to live without. ## Fast healing 5 Test: **Stab yourself** in the lung Success: You heal without sign of injury Failure: You start experiencing great difficulty to breathe Keeping safe from failure: Call emergency services and have them patch you up at the hospital. Blame a mugging or something like that. ## Fast healing 6 I think you get the idea by now... [Answer] If all the rules have been explained to the hero I would suggest he **goes out and gets a piercing**. If I understand your rules correctly he would absorb the part of the piercing that is encased in his body and the hole will seal itself. This is not how normal healing would work at all, and if the wizard was lying (he isn't, but the hero doesn't know that) the hole would grow shut on its own again once the piercing is removed. [Answer] This is simpler than might appear to be the case. The person is now immortal or, at least, so he's been told. When if anyone lives long enough eventually they will die except, of course, if you're immortal. Essentially sooner or later anyone will be faced with circumstances that will kill a normal mortal person. Therefore, the best way to test your putative immortality is to continue living, preferably as if you're mortal, and when that fatal day comes and you're involved in a car accident, fall off a cliff, caught in a fire, drowned while swimming or whatever fatal incident occurs and you're still alive then you've tested your immortality. Basically if you're immortal you have all the time in the world to test your immortality. The odds are in your favour. Something fatal will always occur to everybody. If the test fails and you're not immortal you haven't lost anything (except your life and that happens to all mortals). You will have lived your life taking all the normal precautions of staying alive. Good luck to you fellow for doing so too. If, of course, it turns out you are immortal and you aren't dead, now you can begin to enjoy your immortality in style. Living normally long enough itself will be the best test for immortality. [Answer] You can't. It is clear from the OP that not only does the hero not trust the magician, but also that the purpose of any test is to prove whether or not the magician is lying. The magician may well be telling the truth with respect to any non-life threatening injuries (or behaviour such as over-eating), but any improved healing, even if proven and no matter how magical it may appear, does not prove immortality. Immortality can only be proven in such a situation in which the hero would be dead, otherwise. In other words, if the hero can avoid otherwise unavoidable death, then he is immortal and there can be no alternative proof. Furthermore, the hero has only been granted magical powers previously for limited periods of time - maybe the magician cannot grant any powers permanently. Immortality only makes sense if it is permanent (or at least significantly beyond a normal lifespan) - it cannot be temporary. [Answer] ### Cut off your little toe as a quick test It will hurt a lot. But you will see whether it regenerates. It should not regenerate and if it does you know that magic exists and you can be magically healed. That lends credibility to the story of the wizard. Either that or the toe will not regenerate, which is inconvenient but not really a big problem. People survive every day with far bigger problems. And most importantly: with the right precautions you should be able to survive this little test. ### Monitor your health over the next couple years Once this is confirmed you can just try to monitor your health as much as possible. You shouldn't see any difference in the upcoming 5 or 10 years, but you would expect *something* to happen if magic didn't exist. You can combine this with trying to get fat as hard as you can. This shouldn't really be a *big* problem to check. Even naturally thin people would get fat when eating nothing but chocolate for a prolonged time. ### Assume you are not immortal in the beginning Until the first real checks in a few years you should live your life as if magic does not exist. This is pretty much a safety net for you in case something normally deadly would happen to you. ### Expand your definition of "long-term" regularly After a few years your character will see that he can survive longer than others and he can expand the time horizon he is looking at. He is immortal, so it doesn't really matter when he starts. Every couple dozen years he can then increase what he perceives as "long-term". ### Conclusion All in all your character just thinks he has a very long life span. Not really immortal as he will never test that willingly. Maybe he will realize his immortality if some accident happens that would kill a normal human being. But that is certainly not his goal. --- ### Additional benefits This also prevents your character from going mad because of boredom. He does not perceive himself as immortal - he just thinks he has a very long life span. He still has to care for himself, monitor his health regularly in a very rigid fashion and look out to the end of his life. After all he can't be sure that tomorrow the magic is still there. He can just assume that he probably will live far longer than other people based on his experience up until that point. [Answer] Well, he could do it like in Flatliners: **have a doctor to stop his heart** and wait if his body comes back online before the "safe" amount of time for the brain to exist without oxygen passes. If it does not, the doctor resuscitates him. Of course, that could still mean there just wasn't enough time for him to heal the damage and then he'd have to find a different way. **This method is both fatal and reversible.** [Answer] > > You cannot get fat. If you eat too much, your body temperature will increase to get rid of excess energy > > > Just eat an aweful lot of calories and see if that holds true. Unless your hero already has a very fast metabolism or a genetic disposition for not taking on too much excess fat he will fatten like a piggidy-pig in a few weeks. As he can already levitate and make himself invisible getting money to pay for the foods (or the foods themselves without inconvenient middle-men1) shouldn't provide any big hurdle. 1Including but not limited to: Bakers, Butchers, Confectioners, etc. [Answer] There are a lot of good ideas here, little things like testing the healing factor, and I really like the pool test. But the really smart thing to do is to do nothing overt. The problem with some of the more severe overt testing methods is that they will be noticed. If you punch a hole in your lung and you don't want to die, you need to get in front of a doctor, and that means another person you have to convince to keep your secret. Drawing attention to yourself is likely to be worse than stabbing yourself in the lung. Attention means scrutiny, possibly from the authorities. That means long term plans are going to be harder to deal with. So maybe after a couple of checks that do not rely on somebody else getting involved, stop destruct testing and live your life as an almost mortal man. As a long term check, start taking "before and After" photos of yourself and someone you know. keep this up so you can compare the aging process. Start some long term planning. Diversify portfolios, start long term investments, get some swiss bank accounts. Bearer bonds. That sort of thing. None of these things is dumb for normal people, so this isn't going to attract attention. After about ten years, carefully comparing the aging photos, start looking into ways to move your wealth around. Keep on top of tech trends. Also, start looking into setting up false identities. After 20 years, start planning your death and orderly transfer of assets. Repeat as necessary, and try not to lose your head. [Answer] ## Over Exercise A simple ongoing test of a altered state would be to excercise at a level that is going to leave you really sore the next day. You get to stay really fit and you can test every day without too much long term problems. ### No proof possible My understanding of the scientific method you cannot prove what the magician said was true. That you can only be killed by the methods outlined. All you can do is find a method that will kill you and then unfortuantely you are dead. There is no absolute proof only disproof or running out of tests. [Answer] Hire someone to kill the magician. If he *can* make people immortal, he would do it to himself. Also, you aren't really immortal, are you? Anything that destroys your head, throat or stomach will kill you. so, if the magician wanted to do you harm, he doesn't need to trick you at all. But really, what would be the purpose of testing it? What suicidal thing would you regret not having done because you mistakenly believed it would be fatal? Saving someone you weren't willing to risk your life for? [Answer] Since the hypothesis to be tested is "I am immortal", there is no way to skip the "try to kill yourself" step. Since sticking the fingers in the plug, or whatever quick "suicide" attempt, in case of failure it is obviously stupid. Therefore the only way to test the immortality of the hero is to put him into some "slow killing" path. He can i.e. starts drinking heavily super alcoholics. This in a normal human would quickly damage the liver. After 1 year of this regime, the hero can have his liver checked. If it is still fit and healthy, he got the prove. If his liver is damaged, he can still quit drinking and go rehab. [Answer] You can never be sure by testing it using self inflicted injury. It could be a healing rather than immortality spell, or wear off after some time (years?), or not provide the full protection described to him After all, if you were the magician wouldn't *you* want a hero who, when you reappeared 50 years later to tell him actually he can be killed using something not obvious, and you plan to do so unless he does *exactly* what you ask? Also crossref the Norse myth of [Baldur and Loki](https://en.wikipedia.org/wiki/Baldr) - Baldur was made immortal and all his friends spend their evenings tryingto kill him for fun. The one thing that *could* kill him was a weapon made from mistletoe (a small plant). Unfortunately Loki didn't see a need to tell him or anyone else that minor fact, before passing such a weapon to one of the people playing the game of "use your weapon on Baldur" ...... Your hero's first quest (before or after whatever else he has to do) should be to find someone else learned, who he can trust, and who can tell him what's been done to him. I would suspect that whatever it is, is not known, in the whole cosmos, by only one person..... [Answer] Can you still get sick or ill? I'm assuming from the various other conditions you've listed (can't get fat) that you don't. In which case there is one quite easy method of testing this that shouldn't be fatal if it goes wrong; Eat some raw chicken. If you get food poisoning and are violently ill then you're not immortal, if you don't you may have just got lucky so try again. Repeat at least five times, if you don't get ill at all then the magician was telling the truth. The advantages to this are food poisoning is awful and very obvious, reasonably easy to self inflict but shouldn't be fatal or have any lasting effects on a healthy adult. Other things you could try (with various degrees of success depending on vaccinations etc.) are contracting chicken pox, measles, thrush or other skin conditions (admittedly some of those can have more nasty results if caught as an adult) or even attempting to contract a mild STD (not AIDS or HIV, just something like chlamydia or syphilis). [Answer] Especially if he's as skeptical as you make him sound (doesn't believe even after a rapidly healing cut), the most sensible strategy for him would be to just wait. If he isn't immortal, he puts himself at no extra risk and lives a normal life. If he is immortal, then after several decades he should have more than enough experience proving the truth of his immortality: no aging, fast recovery from injuries, etc. At that point he can make his long-term plans. And since his lifespan is infinite, the decades he waits to confirm his immortality are completely insignificant. Edit: Wait, I re-read your question, and you start by saying that your hero believes in magic because he has been given the powers of flight and invisibility, and saw that they worked. Then you say he still doesn't believe in magic after being granted immortality. So I'm not sure what level of skepticism I should be reading in this. [Answer] In some sense, we're all immortal - until we're not. That is, we've grown up with a set of rules that help us stay alive (and stay complete) for the longest possible time. Those rules say things like "don't ride a motorbike without a helmet and thick leather jacket" and "don't jump off cliffs" and whatnot. We learn these rules because people tell them to us, but also because we test them out when we're kids (falling out of a treehouse and breaking an arm, for example). Your hero just has a new set of rules - and even if he trusted the magician, he'd still have to go and discover those rules for himself. @MichaelK gives a good logical course of action to re-learn the rules of self-preservation, but even those won't really tell your hero what he can and cannot do. Over the hero's (now extended) life, he'll try more and more things and gradually find out what he can and can't do. For example, he might jump out of an upstairs window - for most of us that's survivable, but our hero seems to be able to do it with extreme ease. You and I would think "wow, that was close, lucky I only broke a leg - glad it wasn't worse than that". Our hero thinks "hmm, that was no big deal, let's try jumping out of a 5th story window now". So it goes on, until our hero works out what his new limits are. Presumably jumping out of a 100th story window would lead to such complete injuries that whilst survivable, our hero would still have a long recovery time. That might convince them that jumping out of an aeroplane without a parachute isn't worth the 'cost' of the recovery, even if it's survivable - especially if there's another way down, which may appear more difficult or impossible at the time. [Answer] Testing the drowning part is rather simple: just hold your breath. If you cannot suffocate, you will be able to hold your breath indefinitely, if you can suffocate you will pass out and automatically start breathing again with no ill side-effect beside a headache. (Pro-tip: do not try this at home! It's really uncomfortable if you are not immortal) An easy test for the invincible part would be to get infected with the common cold. If the wizard spoke the truth, then the infection should be defeated without any effects other than a major hunger. As that illness is highly infectious, not getting it if you really try is close to impossible. Asking someone to cough in your face might however cause socially awkward situations. Another test would be to find a sharp object and cut into the tip of a finger with it just deep enough to injure the skin. That part of the body is highly sensitive (it really hurts) and therefore measuring the time it takes to heal becomes very obvious as you get constantly reminded of the state of the injury. It usually takes about a week for such a skin penetration to heal completely, so if it is gone by the next day, that part seems to be true as well. Testing for true immortality like driving a knife through the heart I would simply skip. There is no logical reason to test that. Sooner or later there will be a situation where someone will test that for me anyways. And if it still hurts like crazy there is no need to know, because I would want to avoid such situations at all cost anyways. There is also the risk that I might pass out from the pain, and while my body would dissolve the knife I might not be able to eat/drink enough to support it, and then I'd die despite being otherwise immortal. The hunger part should be a dead-giveaway alone, as a sudden overwhelming hunger would be quiet obvious. As my body approximately heals that way - sadly without the immortality and perfect recovery part - I got some experience with that, if I get ill I eat about twice as much on the day before (my friends keep calling me Frostmourne). Excessive drinking would only be necessary if your body actually needs to replenish fluids, but not for skin/bone/organ regeneration. Or if the body would try to flood out an infection, which probably won't happen with this type of immortality as such infections would be dissolved magically. This form of immortality might result in the following side-effects: * Excessive fear of starving, because you need food to survive, but can't store it, because the body dissolves it. * Excessive fear of blade-like objects, because they could cut off your head. * Allergy-like reactions when the body tries to dissolve otherwise harmless particles like spores or car emissions. * Immunity to any form of drugs and/or medication, even those which could be helpful. [Answer] > > How to safely check if you are immortal? > > > Please, excuse me sir, but it is impossible! There is not a safe way to check if you are imortal or not! It is plain logical think. Do you want to know if you are imortal or not? Jump inside a active volcano, place your head straight in the path of a magnun 45 bullet or similar. Smoking for 50 year or more and dont have a lung disease is not a prove you are imortal, it is not even a prove you are immune to the cigars quimical. Some things are the way they are, basead on logic. Some times there is not a shortcut :) . [Answer] Wait, the only really sure check that is entirely "risk free", as in no more risky than his existing life, is to simply wait and see if he ages. He will probably run into situations which prove or disprove some or all of the rules he has been given by the wizard who has cursed him with immortal life but the ultimate test of his immortality is time. Anything else only proves he can heal not that he'll live forever, twenty or thirty years with *no* signs of aged decline should be convincing enough for even the staunchest cynic. [Answer] Get infected from diseases, such as *Cholera* or *TB* for which medicine exists. But don't take any medicine. If it cures by itself you are immortal. If the disease increases daily you should start taking the medicine. [Answer] **Visit a Hypobaric Chamber** [Hypobaric chambers](https://en.wikipedia.org/wiki/Hypobaric_chamber) are routinely **and safely** used for training people to cope with the effects of a high-altitude/low-oxygen environment: > > A hypobaric chamber, or altitude chamber, is a chamber used during > aerospace or high terrestrial altitude research or training to > simulate the effects of high altitude on the human body, especially > hypoxia (low oxygen) and hypobaria (low ambient air pressure). > > > One of the powers the magician claimed to bestow is: > > You cannot drown or suffocate. However, your body will need extra > energy to work under water or in unbreathable gasses. > > > In theory you no longer require oxygen as long as you have food (I assume that's what "extra energy" means). So all you need to do is visit any high-altitude training center with a hypobaric chamber, and pay them to take you and your dinner for a ride. Have them take you to an impairing but not-immediately-life-threatening altitude to start with, like say 25,000 feet. You sit and enjoy your dinner and you either start rapidly becoming impaired from the low oxygen levels (in which case the lab technician repressurizes you, or you grab the nearby oxygen mask, or whatever) or you don't. If you don't, the technician can gradually increase the altitude even further. Eventually you reach an altitude where a normal person would lose consciousness and rapidly die from lack of oxygen. If you remain conscious and unimpaired, then congratulations; you may not be fully immortal, but you do seem to be immune to suffocation and no longer required to actually breathe! **Why it's safe** Someone else operates the chamber for you and observes you the entire time. If anything goes wrong, they can rapidly restore pressure and give you supplemental oxygen. If they're quick you probably won't even suffer any permanent brain damage from the hypoxia. Just try not to break your nose when you pass out and fall over. You're also not exposing yourself to any exotic of potentially toxic atmospheres. You're just slowly removing O2 from the environment, and immediately restoring it the moment anything goes awry. **What are the risks?** Maybe the tech is incompetent or hates you for some reason. They lock you in the chamber, take you to 50,000 feet (good luck forcing the door open with the chamber under that much negative pressure), and go play Tetris for a few hours. You'd better hope you're *really* immortal. Or maybe the chamber suffers a technical fault, and depressurizes too much or cannot be repressurized when something goes wrong. *Probably* these things have failsafes built in so that things like that *mostly* never happen. **What are the limits?** With this method you only find out if you're immune to suffocation as long as you have a source of extra energy. It's possible that this aspect of the spell works as advertised, but others do not. I wouldn't suggest you do this, and then move on to the "shoot myself in the face" test. Better to do it, wait 10 years, and confirm that you're not aging instead. And then you just *assume* you'd pass the "shoot myself int he face" test, without actually trying it. [Answer] # You can't, and he's not. You can't *because* he's not. The only way to prove that he is not immortal is to die. As the wizard *said* there are conditions in which he can die, he is presumably not immortal - otherwise the wizard would not have felt the need to explain things that could kill him, unless the wizard is lying not about the immortality, but the mortality. This is just fast regeneration. [Answer] Ever see Flatliners? Get a medically trained buddy to stop your heart and see if it starts up on it's own, otherwise attempt resuscitation. The only way to test immortality is to die, there isn't a "safe" way to do that. How is this [magic] energy gathered/replenished to heal or survive underwater? If it's through food, hence starvation being a cause of death, magic typically requires a lot more calories than a person can eat. If it's replenished some other way, why would they need food to survive? Or a body for that matter? as long as they can gather magic energy they should be able to survive as only a head since biological processes aren't necessary to survive, evidenced by surviving underwater. [Answer] Why not just wait until the hero accidentally injures himself? Then he could eat a lot and see his body temperature and injury. [Answer] Since his body only need extra energy to work in an ambient filled with unbreathable gasses, he just need to close himself in a garage with a car engine turned on. If after some minutes/hours he only feel tired, then he is an immortal, if he start to not breath well (or feel some of the symptoms of the CO2/CO poisoning) then he can exit the garage and he is not an immortal. ]
[Question] [ For my non-European readers, here is an excerpt of what the [GDPR](https://en.wikipedia.org/wiki/General_Data_Protection_Regulation) means: (emphasis mine) > > The General Data Protection Regulation (GDPR) is a regulation in EU law on data protection and privacy for all individuals within the European Union (EU) and the European Economic Area (EEA). > > > **A processor of personal data must clearly disclose any data collection**, declare the lawful basis and purpose for data processing, how long data is being retained, and if it is being shared with any third-parties or outside of the EU. > > > I haven't been notified by Santa or his elves that he is collecting data about me. And mind you: my name and surname **are** my personal data, not to mention whether I have been good or naughty. Moreover, Santa also needs my full address to deliver my presents, and again, **that is also my personal data**. Santa hasn't notified me whether he is updating his Privacy Policy, so I assume that Santa stopped collecting this data, at least for Europeans. Does it mean that Santa is delivering me **nothing** this Christmas? If there is any way around this, can you please tell me what it is and how Santa can deliver me presents while still being compliant with the GDPR? Please assume I haven't been naughty. [Answer] **Santa's data collection has always been compliant with GDPR, so he has no need to change his ways.** The nature of his data collection is more transparent than most companies, and he is open to updating his records if you contact one of his representatives. For example, he makes it clear that he is operating in your town: > > You better watch out > > > You better not cry > > > Better not pout > > > I'm telling you why > > > **Santa Claus is coming to town** > > > The legitimate business purpose of his data collection is to create a list of those who are naughty and nice this year: > > **He's making a list** > > > And checking it twice; > > > **Gonna find out Who's naughty and nice** > > > Santa Claus is coming to town > > > He even gives some examples of what data he's collecting: > > He sees you when you're sleeping > > > **He knows when you're awake** > > > **He knows if you've been bad or good** > > > So be good for goodness sake! > > > --- The GDPR has some other requirements to it, [such as an EU-based representative](https://politics.stackexchange.com/questions/30509/how-are-gdpr-fines-actually-enforced-for-us-companies-with-no-physical-presence/30513#30513) being necessary for operating in the EU, allowing users to request data updates, and getting consent for data collected. Thankfully for Santa, he's been operating compliant representative systems for decades: Just go to any mall during the holiday season to meet with [a representative](http://tvtropes.org/pmwiki/pmwiki.php/Main/MallSanta). To ensure open and accurate records, the representative will ask the child if they've been naughty or nice that year and what type of present they want. As long as the child's parent/legal guardian is nearby to confirm the data change requests, Santa will be happy to update his database to ensure the naughty/nice data is accurate and that the requested presents are delivered. As for consent, the children are obviously too young to provide consent and must rely on their parent/guardian to consent to Santa's data collection. **I doubt there's a single house that is receiving presents from Santa without the parent's explicit consent**, and I'm sure we've all been told by our parents at some point to "be good or Santa won't give you presents this year!". [Answer] Santa is Christian priest (bishop as far as I remember). As you can see [here](https://edps.europa.eu/sites/edp/files/publication/16-02-25_personal_data_protection_church_warsaw_en.pdf) he is covered by exemption: > > The new Regulation will maintain the existing exemption which allows churches and other bodies with a 'religious... aim' to process sensitive data: > > > * 'in the course of its legitimate activities...'; > * '...with appropriate safeguards'; > * '...on condition that the processing relates solely to the members or to former > members of the body or to persons who have regular contact with it in connection with its purposes'; and > * on condition that 'the data are not disclosed outside that body without the > consent of the data subject'. > > > As no one ever saw his lists, and we don't know about any other activities, we can safely assume above bullets are met. [Answer] Well you are making a fundamental misunderstanding about the GDPR (as many have), that consent is the only basis for holding and processing information. There are actually [six legal bases](https://ico.org.uk/for-organisations/guide-to-the-general-data-protection-regulation-gdpr/lawful-basis-for-processing/#ib3) for holding data (you have to scroll down a little as the link doesn't work properly). Those six bases are: 1. Consent 2. Contract 3. Legal obligation 4. Vital interests 5. Public task 6. Legitimate interests So let's look at each of them and see if Santa has any basis for collecting our information. **Consent** - Actually this one may not even be as troublesome as it first seems. Presumably we're all writing letters to Santa asking for presents, this could potentially be seen as a form of consent for collecting our data, though I think that's a little iffy. **Contract** - The letter to Santa could also form the basis for a contract for the provision of services (present delivery), so I think this works. **Legal Obligation** - Unless you want to argue that Santa is legally obligated to perform his duties I don't think this one works. **Vital Interests** - No one is going to die if Santa doesn't do his job, probably doesn't work either. **Public Task** - I think this is a strong contender. From the website I linked above; "the processing is necessary for you to perform a task in the public interest or for your official functions, and the task or function has a clear basis in law." I would say the worldwide provision of joy and happiness is in the public interest, and the processing of our information is definitely required for Santa's official functions. **Legitimate Interests** - This is a little of a grey area and many businesses have used it as the basis for continuing to hold and process information, I see no reason why Santa couldn't do the same. So in short, there is no real issue at all and Santa can continue doing what he needs to do as long as he properly deals with our information and updates his privacy policies. [Answer] Santa already exempts himself from the petty concerns of local laws. He invades sovereign airspace each year and unlawfully enters private residences. The GDPR seems to be a lesser violation compared to others he willfully commits each year. Why should he concern himself with the GDPR? [Answer] ### Everyone gets the same present - a letter about sending your personal data This year we will all get a letter about the updated general terms and conditions and how you will be required to send a certain set of information to Santa so that he may send you your presents next year. Everyone will be required to send their address, name and age. You will also have to allow your parents to send Santa the data about you being nice or naughty. In case you don't want to disclose the naughty-or-nice information you will receive a generic probably-not-that-naughty present, which will most likely consist of old chocolate he found lying around in the elven workshops. Be careful to send your data as fast as you can. It will be harder to get into contact with Santa after the timeframe he had allocated for everyone to send in their address, name and age. If you don't send that information you will receive nothing because Santa is not allowed to use your address any longer. If he still sends you something you can sue him - and thereby make sure that lots of children will cry because they won't get any presents after the EU is done with Santa. Good job, now it's clear on which list you are... There is also talk about Santa cooperating with the Easter Bunny in 2019 for a late present delivery. [Answer] I'd like to take another route to answering your question: **He simply doesn't care.** For years, he has been punishing kids and breaking into houses; despite attempts from kids and governments, he has never been caught. He doesn't have an aviator's license or a landing permit for his sled, while flying very close to houses and otherwise endangering people. Though, if you put him to a D&D scale, he may be chaotic good, he is nonetheless chaotic: he breaks the law to reach his goals. I'm certain he doesn't pay VAT on his gifts. Also, the working conditions of his elves are questionable. But it's the same with every other criminal: As long they can't catch him, he will continue. [Answer] Note: This answer pertains to Santa Claus, as distinct from St Nicholas, Sinterklaas, Krampus, etc. - as per the question. He is not bound by GDPR. > > an entity or more precisely an "enterprise" has to be engaged in "economic activity" to be covered by the GDPR > > > <https://en.wikipedia.org/wiki/General_Data_Protection_Regulation> What qualifies as "economic activity"? I'm glad you asked: > > ... the Court determins that an activity is economic on the basis of two criteria of agreement and renumeration > > > (from <https://www.springer.com/cda/content/document/cda_downloaddocument/9789462651166-c2.pdf> ) I do not agree with other posts that the recipients of the gifts agree (in the legal sense, nor in any sense that would stand up in court). I am not aware of any way a person can "agree" to be the recipient of gifts from Santa (there are obvious ways to object, of course). Santa Clause also does not seem to meet the criteria for remuneration. He brings "gifts" or "presents" (<https://en.wikipedia.org/wiki/Santa_Claus>); "A gift or a present is an item given to someone without the expectation of payment or return" - <https://en.wikipedia.org/wiki/Gift> In many cultures, something that may be considered payment is left for Santa (e.g. milk & cookies in the US & Canada; sherry or beer and mince pies in Britain & Australia; rice porridge in Denmark, Norway & Sweden); however, I can find no source that indicates that failing to leave these items will result in suspension of gifts. - <https://en.wikipedia.org/wiki/Santa_Claus> Also: > > 'enterprise' means a natural or legal person engaged in an economic activity, irrespective of its legal form, including partnerships or associations regularly engaged in an economic activity. > > > As far as I can tell, Santa Clause is neither a natural nor legal person. Human Beings "acquire legal personhood when they are born (or even before...", juridical persons "acquire legal personhood when they are incorporated" (<https://en.wikipedia.org/wiki/Legal_person>). I am not aware of Santa Clause having been born, nor incorporated. Addendum: There was a question if "being nice" qualifies as remuneration. I would argue against this for the following reasons: * If an item is traded for remuneration, it is, by definition, not a present. The items are clearly declared as presents. * Santa is not the recipient of the "niceness" (in almost all cases). * Although it is clearly document in "Santa Claus is coming to town", (H. Gillespie et al.) that "he's going to find out who's been naughty or nice", "He knows when you've been bad or good" and "He's making a list", there is nothing in this thesis that claims that this list affects the presents. Wikipedia claims it does, but none of the sources it cites (that I checked) back this up. Does anybody know of a reasonable source for this, or is it just an urban myth? Does anybody know of a child that has not received a present, *because they were naughty*? [Answer] Santa will no longer be giving presents in EU region. Santa will only provide means of transportation for *Ded Moroz* who exist in time pocket created in USSR in 1946 and as a citizen of USSR is not obligated by EU law as law cannot work backwards. So your future present WAS delivered before GDPR. [Answer] IANAL but here is my take of things. In a nuthsell, GPDR requires any businesses/organizations/pineapples that have users in the European Union to: * Disclose what they do with the info they have on you, and why they need it; * Disclose with whom they share that information, and what those other businesses/organizations/pineapples do with it; * Allow you to order them to "forget" you. Once you give them the order, they (and their partners) have to delete all your data that **can be used to identify you**. All within limits of reasonability, of course. You can't order the government or a bank to forget that you have not paid your credit card bill and your income tax in months, for example. --- Santa has to adhere to the GDPR only for some europeans. For starters, many european countries are not members of the EU, such as Norway and Serbia. Santa Claus also [does not operate in Italy](https://en.wikipedia.org/wiki/Befana). --- What would most probably happen is that the elves in charge of Santa's legal department will have sent every parent or legal guardian in the 28 (soon to be 27) member states a letter around May 25 stating that: * They collect personal data from their children in order to assess a naughtiness score; * They are the keepers of the data. The processors of the data are Tencent and Alibaba, two chinese companies that specialize in social credit systems; * The legal guardian or parent may choose to opt-out of the system at any time, if they so wish. They may also request their children's personal data removed from the system at any moment, no questions asked; * However, opting out means their kids will never receive christmas presents again, at least until they join the program once more. Gifts not received due to non-participation will not be resent when they rejoin; * Participation does not imply in presents. Should a child receive a low reputation score due to naughty actions, they may instead receive a lump of coal, [a visit from Krampus](https://en.wikipedia.org/wiki/Krampus), or whatever punishment is seen as fit for the culture of the country where they live. Adults capable of having children will also receive a notice that in the future, they will have to manually input any future children's data in the system if they wish to receive christmas presents. Of course, people who have opted out of any social credit system will not receive such messages. --- Finally, Santa will not be the only one sending such letters. So will every imaginary folklore people who bring any joy to kids: * The tooth fairy (and her rat affiliates in France) will promise that any data linking fallen teeth to their owners is anonymized; * Sandman will make sure that parents/legal guardians dream with his new EULA ASAP. Their children will not have sweet dreams until their parents agree to it. Should they opt out, their children will have neither dreams not nightmares. * When winter comes, rather than patterns on windows, people will see Jack Frost new service terms, and a couple of ice buttons for opt-in and opt-out; The Easter Bunny is the only one having an easy time. AFAIK in Europe he does not hide chocolate eggs for kids to look for - rather, people paint actual eggs and give those as presents. He will provide an easy opt out for people who don't want to pay him his royalties. [Answer] A letter to Santa is considered to be implied consent for data storage, as the data is required for the requested delivery of presents. This is similar to the implied consent between a patient and a healthcare provider. Santa will use the data for the purposes of direct gift-giving, without breaching confidentiality. If you would like to remove your data, or would like to access your data to see if you are considered naughty or nice, you will have to write another letter to Santa. Santa will have 30 days to respond to your request. If this is in terms of working days, you should expect a reply by 2048. [Answer] Santa only has output; no income. Therefore, if EU decides to prosecute for an alleged violation, the prescribed percentage penalty is not a burden. Besides, EU has no courts at the North Pole, and no extradition treaty. So it will be hard to collect that penalty of €0. [Answer] **Extortion.** He simply informs everyone involved in the enforcement of GDPR that if they take action against him he will replace everyone's present that year with a note explaining why they didn't get what they asked for and giving the names and addresses of those responsible. Nobody's going to want to be the one who spoiled Christmas for everyone in the entire world. That would be a good way to get lynched. [Answer] Santa exists in a parallel world where this law doesn't apply. Children in our world who believe that Santa exists have identical copies in worlds where Santa does exist. If we give them a present and tell that it's from Santa and they believe that to be true, then what we have here is the exact copy of the child who really got that exact same present from Santa. The moment the child finds out that Santa does not exist, the child diverges from his/her copies in the worlds where Santa does exist. [Answer] GDPR is apparently explained as General Data Protection Regulation. Actually, and thanks to the lobbying of elves and little people, the legislature has come with that clever explanation to hide its real meaning: Gift Donors Privacy Relieved. Santa, together with other Gift Donors, such as the Tooth Fairy, is exempted from observing the privacy of his "customers" to better serve their interest. [Answer] If you are over 16 and have not consented to Santa collecting your personal data, it is very likely that you will not receive presents from Santa. If you are under 13, then the GDPR allows your parents to consent on your behalf, so if they have done so, you likely will receive presents. Between 13 and 16 it depends on the jurisdiction. [Answer] ### He would just remember everything himself. He's not a regular person, he's Santa, why shouldn't he simply know all he needs to know? In fact, even under GDPR, no one is obliged to call everyone whose number they have in their head. So personal memories are very clearly exempt from the "any collection of data" clause. Furthermore, Santa is not in any way a commercial entity and doesn't act commercially. To project our usual human assumptions about our economic system onto a being like Santa is flawed reasoning. [Answer] Santa did forsee this decades ago. Once he understood where our law-addicted society was headed, he instructed his huge apparatus of elven servants to foster the belief that he didn’t exist. This strategy has been so successful, that no member of the EU executive dares taking action against him, for they would be branded as crazy and sent to uncomfortable places. In fact last year around Christmas I saw something big and distinctly sledge-like in the sky. I was naive enough to point it out, but when I heard someone at the table mutter „97, hampf, dampf, retirement home“, I started giggling and pretending to be drunk... In fact, the day after I was visited by a strapping young elf who made clear that Santa didn’t wish... Oh, let me get the dooooooor [Answer] **He doesn't have to** I might point out that as he is based in the North pole, an area that doesn't fall within the EU's borders, arguably he doesn't have to *technically* comply with GDPR because the regulation only impacts European businesses, and Santa isn't in Europe. How GDPR impacts countries outside of the EU is another question altogether, and is certainly a grey area legally because how would the EU enforce it's laws over that of another sovereign nation state or a company located in another country? They could certain legislate some absurd law (sounds like great grounds for a story) but then how can they enforce against a man who travels faster than the speed of light and can disappear down small chimneys? I'd love to see some lawyers try to serve notice to the man in red in the North pole. A full arctic expedition just to serve some legal documents. On a legal technicality, GDPR allows for data to be retained where it's needed to provide a service - in this case, knowing the address and whether they're children who meet the eligibility criteria (asleep, good) for present delivery is fundamental. Although, if he's bound to GDPR, then he's probably also bound to anti-discrimination laws regarding good and bad kids. [Answer] **The elf's head loophole** Santa could hire more elves and teach them memorization techniques for committing all the personal information to memory. The elves would self-organize into groups by cities and would then label themselves with their city region that they have memorized. Santa can then have easy access to the data without violating any GDPR restrictions. I'm not a GDPR expert but I can't imagine it prohibiting people (or elves) from remembering personal information. To stop Santa from using this loophole I guess the next move for GDPR is to prohibit systematic memorization of personal information. But until then Santa is likely to be wanting an AI for predicting which presents that are going to be popular next year so that he can get his elves producing them already. We better stop him before he attempts to do this because it will require quite a few elves in some really ridiculous jobs. Although it would be a really impressive setup of elves! [Answer] You have some of this backwards, my friend. Santa's mission statement is to compel boys and girls of the world to be good, not to be good himself. Santa is allowed to be naughty, just not you. He collects data using his custom KrampOS, derived from Tails, and running relays off of the Dark Web and a network of numerous reindeer-launched high-orbit stealth satellites. While in recent years, simply coming up with an Amazon partnership and using their cloud services, customer records, and a basic probability has been tempting, the northern state of Santonia is seen to be a rogue state by the EU and numerous other territories. In the course of a single night, he has been sighted breaking into the personal properly of 448 million EU citizens, leaving anomalous and disguised objects, devouring food, and promptly leaving under the cover of darkness. This is already a blatant violation of personal property laws, and has been going on for many centuries in one form or another. Santa *was already unequivocally guilty when GDPR was passed.* Taking personal data is just "the icing on the cake". Santa is a clear and present danger, and a rogue agent. He is a master infiltrator. His folk-hero status may have given him some protection from above-ground justice, but make no mistake—he cares not for the EU or its laws, and is to be apprehended on sight. ]
[Question] [ So, I've got this idea for a short story. Some researchers find a forgotten manuscript hidden locked away in an ancient tomb. While they are working on it one of them pastes part of the text into a Facebook announcement and **Facebook automatically translates it**. This links Facebook to the nether realms of madness and despair. Ph'nglui miglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn The translated text appears in the browsers of everyone reading any Facebook page translated to the local language. Those people reading it (some out loud) provides impetus to a ritual which centers on the London data center where the text was first translated. Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn The resulting power surge fries most computers in the local area unless they are actually part of the data center, including those used by the local sysadmins for monitoring and control. In particular every monitor now displays nothing but screaming tentacled beasts ripping through from another reality. *Warning: Tentacle beasts may become real if you stare at them for too long.* The ritual lives on in the heart of the data center, as creatures of madness attempt to rip through into our reality from the nether realms beyond. P҉h'ng͟l͞ui͘ ̷m̴gl̛w'naf͏h C͡th́ulh̡u R̕'̡l̶y̷e̕h ̀wgah̕'̧nág̵l fhtágn **What can our heroic sysadmins do to shut down the data center and save the world?** Remote access is not possible and physically entering is dangerous to both body and sanity, so answers will be rated based on entering the data center as little as possible and for as short a time as possible. P̦̰̞̼̤̰̼͇̞͝h̵̗̱̫͇͓́ͅ'̸̼̣ǹ͕͚͠g̵̷͎̭̝ḻ̮̹͓u̷͙̞̳̞̭͜͠i̥͎̻̗͚̜͞ ̸̗̹̰m̧̖͉̩̻̺̜̭͘̕g͙̺̤̩̰̮̜̫͟l̛̮͙̻̫̻w̨̹͚̘̻̙͇̥͔͚'͙͉̫̗̮͔n̹͉̳̪̫̭͝a҉͍͙͔͍f͈͈͔̖͈͡ḥ̤ ̢̠͇̝͎̀C̢̰͖̜͚ṭ̟͓͍͕͚͍͠ͅh̤̫͙̪͉̮̖͟u̢͔͙͖͓̱͙̦͘ͅͅl͏̧҉̼̠̠͚͕h͈̯̘͔̝͍̟́͢ụ̵̩͍͡ ̟̺͚͙̺̮̲Ṛ̬͔͚̺̝̠'̠͠͠ͅl̡͈͎͠ỳ̟͉̮̼̲ͅe̵̼̠̩̤̟͎̹̕h̞̯̪̹ ̸̺̗̩̹̟̪̟̣͎w̹̞̤̞͕͍̦͞ǵ̶̠̙͖̱̠͚͚͓a̷҉̮͖h̴̲͔͉̯͍̰͖̯͘͜'̛͚̭ͅn̵͓̫͎a҉̶̪͢ǵ̡̰͎̻̲͍̣̰l̷̡̫̗̭̯̭ ̮̬͍̫̺̟̯͖f̶̢̭̮͕̭h̶̯͖t̵̠̹à̶̯̩̩̫̬̘̳̫͡g̛̬̻̦̜͙n̵̟̘̝ Note that this is a secure and robust data center with fully redundant architecture, backup power supplies, and UPS. P̢̢̲̭̘̣̪͉͞͞h̴̛̫͉͖̜͙̳͎̕͞͠'̶̀͢҉̯̞̹͈ṉ̶̘̠̯̬̭̖̳͘͞ģ̵̛͠҉̰̝͇̩͍̗͍̘̫͈̺̭̥͉l̨͍̘͔̰͔̖͍̹̠̭̱̰̖͙̦̦͎̕͟u̢̡҉̲̭̲̺̮̖͖͖i̴̢̹̳͉͎̥̪̜͎̼̣̦̖̻͈̖͉͚ͅ ̵͏͇̗̭ͅm̶̨͍̤̪̱͇̤̬̥̥͔̼͍̠̼͕g̷̷̰̩͙̪̫͉̺̯͘͟͠ļ̶̭͇̘̮̕͢ẃ̵̸̷҉͕̬̠̥̤͖̙̲͇̼̹'̺̩̖̟̣͈̖͙̤̫̰̗̯̀͡ń̷̴̶̰̮̺͔̼̺̹̘̟a̷̰̪͙͇̤͓̤̭͎̦͕̻f͏̨͙̰̘͔̟̜̠͈̯̻͕̖̳̝̝́͘ͅḩ̴̛͉͉̲͇̠͙̣̩͙̩͚̮̼̺ͅ ̧̛̟͓̤͇̯͍̫͖͎͈̫̳͓̞͘Ç͘͏͈̹̠̙͎̳̯͚͔̼͙̻͔͖̲̩̹̕ͅt͏̖̲̤̫̤̫̼̪̥̠͙͚͍̭́ͅḩ̡̲͈̫̯͚͉̱͍̳͝ù̧͙̭̙̻̲̙͚͔̲̬͚͢͝͡ḻ̴̵̨̹͉͙̟̯̞̠͔̦̝̩͜h̶̼̜̦͖͍͎͍̕ṷ̴̶̢͙̗̬͇̯̞̗̰̣̬̥̲̣̦ ̵̲͍̩̭̩̗͈͚͟͝R͏̛͘͟҉̫̝̞̪̣̪̻̤̼͖̪͎'̛̯͚͎̳͎̼͓̘͉͢l͟҉̵̘͈͙̣̹̜͍͎̬̺̹̪̜̀y͏͓̞̬͙̥̞̦͎͖̞͖͎̖̀e̶̵̡̺͉̯̭̣̗h͇̺͇̖̼̻̟͓͜͟͜͞ͅ ̴̷̡̨̪͍̙̳̞̭̙̫̯̘͚͇͚̼͙͟w̧̮̜̯̭̘͈̫̳̖̕͜͠g̢̨̗͖̬̠͎͓̱̞͓̭̯̺͕̭̯̦ͅa̴̠̘̬̩͍͜ͅh̵̷̨̜̻͔̖͈̤͈̩͔͈͇̩̞̲̜̩͍̺'̸̨͇̞̜͈͟n̨͟͞҉̤͚͎͇̣̺͚̻̖͖́ͅà̻͉̙̲̲̞͘͝ģ̙̗̙͓̜̣͔̥̫͟͡l̴̨̨̼͚̫̞̙̳͙͢͟ ̢̦͚̲͇̞̺̗̫͇f̸̸̫̠͖͙̜͉̲͖͓̭͇̦̭̩̲͡͠ḩ̸̲̤͍̖̻̣̝̼́̕͝ͅt̴͝҉҉̵͔̮̞̪á̢̕͢͏̗̯̗̙͙͉̪͓͙̣̰̣g͏̶̡͓̤͍͖̜̠̜ͅn̴̶̛̝̼͉̠̻͓. The data center is located in a major city so collateral damage is acceptable if absolutely required, but should be minimized where possible. Į̴̱̩̥̘̱͈͈̮͙̘͙̣͓͓̙̹̲̫́͢͠t̨͕͎̣͇̫͘͢ ̡҉͕̭̙̦̩̱̟̮̭̞̱̮̺͕͈̘c̶͔̼͍̤̯̦̭͙͓̟̱͘ͅo͏̛̮͍͙̯͔̣͘͜m̨̢͕͎͕̪̹͕̬̀͠e̱͈͓̠͚̺͖̻̦͙̗̥̼̼̬͝ś̸͖̪͍̱̳͉̤̫̮͎̗̗̯͉̫͉̻͞!̶͏̶̛̝̺̭̱̤̻̩̟̳̙͓͙͍͇͎̙̥͔́ [Answer] The, perhaps boring and uncreative, answer might be to cut the external internet connection to the datacenter. Even if the datacenter is internally shielded, it needs its internet connections in order to be effective. The internet connection has to reach the outside, unprotected world at some point. Cut the fiberoptic cables at that point. Now, it's just a matter of containing the datacenter. As much as it keeps our heroes out, it keeps i̷̢̨̫̰͓̦͖̙̹̱͔̯̮̟͎͖͖͂̊ͦ̓̈ͩ̏ͨ͆̽ͤ̽̃ͤ͟t̴̷̡̻̻͍̘ͣ͊̍ͩͫ̋͋̊̊̚ ͣ̋ͫ̈̾̇̆̀͐̐ͤ͋҉̧̳͉̳̟͖̭͓͇͖̦̤̦̖͔͚͠͠c̴̶̷̢̟̱̰̜͉͉̬͓̭̰ͫ̊ͩ̑̽̎̿̓̀̆ͣͤ̆ͯ̐̊ͯ͘ͅợ͍̻̘͋̾̾̋ͭͯ̒ͭ̅͗͢͞m̴͖̖͍̫̣͓͔͉̤̝̱͇͖̯͆̐͆̓̀̅̓̐̓͋̀̀e̛͛̃͂͐ͬ̿̐̌ͥ̊̽̆͆ͫ̽̍͛͆͡͏̢̧̭͕̙̤s̘̝̻̩͔͖̹͍̹͖͇̣͓͒̎ͥ̃̀͢ in. In this state, our heroes bury the datacenter with as much concrete as the world can produce. Society lives on, and eventually, the backup power will run out. Now, the data center is effectively a new tomb, to be discovered again in a few thousand years. Researchers in the future will find the hard drives from the past, and when they try to recover the data, they accidentally execute it. Į̛̪͉̜̕t͉̫̼ ̠͙͚̮͙̻spreads at the speed of light through the then-ubiquitous neurocomputers, which is the *true* end of human civilization. [Answer] Last time this happened at my job, we were glad our servers were running Windows 10, which forced a shutdown for mandatory updates... [Answer] We are talking about sysadmins and an event endangering uptime? Just call them and send them in. Nothing can stop a sysadmin when their uptime is endangered: <https://xkcd.com/705/> [![A terrorist is holding a gun and talking on a cell phone to the boss. Terrorist: We took the hostages, secured the building, and cut the communication lines like you said. Boss: Excellent. Terrorist: But then this guy climbed up the ventilation ducts and walked across broken glass, killing anyone we sent to stop him. Boss: And he rescued the hostages? Terrorist: No, he ignored them. He just reconnected the cables we cut, muttering something about "uptime." Boss: Shit, we're dealing with a sysadmin. Title text: The weird sense of duty really good sysadmins have can border on the sociopathic, but it's nice to know that it stands between the forces of darkness and your cat blog's servers.](https://i.stack.imgur.com/Lrhf4.png "The weird sense of duty really good sysadmins have can border on the sociopathic, but it's nice to know that it stands between the forces of darkness and your cat blog's servers.")](https://xkcd.com/705/ "The weird sense of duty really good sysadmins have can border on the sociopathic, but it's nice to know that it stands between the forces of darkness and your cat blog's servers.") Another option is to failover to the redundant datacenter in another country and route all traffic to it. Then disconnect network and power connection to the infected datacenter and wait until the UPS stops working (normally few hours or days). If you don't want to wait that long use military weapons like aerosol bombs (they implode buildings and caves and remove all oxygen and can also be brought in via air ventilation ducts, so no need to enter and no damage to the city except maybe the datacenter missing. [Answer] Problem is, most mobile devices these days are quite competent computers. The moment the first frustrated millennial opens up his Facebook app to complain about the lack of a nearby Starbucks on a 50 feet radius neighborhood and sees the translation, it's over - like [Leto II](https://en.wikipedia.org/wiki/Leto_II_Atreides), a pearl of Cthulhu's consciousness will live in every iPhone. Our heroes arrive at the conclusion that the best way to stop the invasion is to join Thefacebook back in 2003, as core engineers. They should then depart on a journey to find [Hackerman](https://en.wikipedia.org/wiki/Kung_Fury), the only operator known to be able to hack time. [![enter image description here](https://i.stack.imgur.com/hrZRFm.jpg)](https://i.stack.imgur.com/hrZRFm.jpg) Mandatory mullet. Solution then would involve: * Argue with him about destroying the datacenter; he then goes on a [Gandalf-to-Frodo-in-Moria-about-Gollum like talk](https://www.youtube.com/watch?v=IrOqnZdvI6M), and convince them to let the datacenter survive; * Going back in time, in full 8-bit CG glory; * A gratuitous fight scene with a [corrupted Operator from Hell](https://web.archive.org/web/20160126123613/http://bofh.ntk.net/BOFH/0000/bastard-sm1.php) that travels with them and tries to jeopardize the mission; * Installing a backdoor on Facebook's data center, based on a [Timex Sinclair](https://en.wikipedia.org/wiki/Timex_Sinclair) disguised like a [teapot](https://en.wikipedia.org/wiki/Hyper_Text_Coffee_Pot_Control_Protocol); [![enter image description here](https://i.stack.imgur.com/Ova0Pm.jpg)](https://i.stack.imgur.com/Ova0Pm.jpg) Timex Sinclair 1000, custom case mod * The Sinclair, basically a silicon brick with resistors as thick as your thumbs, shrugs off the dark energy shockwaves; * In a revival of the [famous NCIS scene](https://www.youtube.com/watch?v=u8qgehH3kEQ), [Jeff Atwood](http://blog.codinghorror.com/) and [Jon Skeet](https://stackoverflow.com/users/22656/jon-skeet), sharing the Sinclair keyboard and typing furiously, write a broker service that pumps the whole cheezburger.com media repository into Facebook, clogging their storage; * The *coup de grace* - poison Facebook's distributed Redis cache key that contains the translated text with adorable Emojis: > > (づ￣ ³￣)づ ʕ•ᴥ•ʔ (─‿‿─) ~(˘▾˘~) > > > The ritual collapses; world is saved; everybody sees cute pictures of cats. World leaders approve a global ban on Facebook, immediate cease-fire on all war fronts and world-wide approval of same-sex marriage. The United Nations flag is updated to include that emoji line. A new dawn for humanity comes. **Famous quotes** [![enter image description here](https://i.stack.imgur.com/DPDsU.jpg)](https://i.stack.imgur.com/DPDsU.jpg) Sources: [1](http://www.news.com.au/russell-crowe-and-his-new-movie-noah-are-the-centre-of-a-religious-storm-complaining-about-his-depiction-of-the-genesis-story/news-story/b9218791ebaa12242693d7a707fc54af), [2](https://www.reddit.com/r/Cyberpunk/comments/382dy1/hackerman_from_the_movie_kung_fury/) *'U can haz cheezburger!'* - Jeff and Jon, hitting `Enter` in unison **Epilogue** A kid finds an abandoned iPhone. Excited, he picks it from the floor. As the camera focus on his face, we can hear Siri saying... > > Į̴̱̩̥̘̱͈͈̮͙̘͙̣͓͓̙̹̲̫́͢͠t̨͕͎̣͇̫͘͢ ̡҉͕̭̙̦̩̱̟̮̭̞̱̮̺͕͈̘c̶͔̼͍̤̯̦̭͙͓̟̱͘ͅo͏̛̮͍͙̯͔̣͘͜m̨̢͕͎͕̪̹͕̬̀͠e̱͈͓̠͚̺͖̻̦͙̗̥̼̼̬͝ś̸͖̪͍̱̳͉̤̫̮͎̗̗̯͉̫͉̻͞!̶͏̶̛̝̺̭̱̤̻̩̟̳̙͓͙͍͇͎̙̥͔́ > > > . [Answer] **Facebook already solved this by accident.** Surprisingly few people noticed anything when this happened last month already. Basically, Facebook algorithms do not send a post to everyone's friend of a friend of a friend... Only a few friends initially get the new post and immediately go insane. However, since they have lost their minds, they do not "like" the new post (though some might argue that liking posts is mindless behavior itself). Facebook decides this post must be boring since no-one likes it and does not distribute it further. --- Facebook may not be so lucky next time. If the post gets accidentally linked to a funny cat video, people may reflexively like the post faster than the elder god insanity kicks in. [Answer] We'll just have to turn Cthulu's newfound strength into a weakness, using one of the oldest computer-enemy tropes known to man: the virus. Since we can't hack into the datacenter directly to deposit the payload, we'll have to take advantage of the Facebook-Twitter connection instead. The tricky part is going to be in developing a virus that can be contained in only 140 characters. (The solution will probably have to utilize some obscure Unicode characters). Get enough people, who've linked their Facebook statuses to their tweets, to retweet it (talk about *going viral*) and it will start to permeate the databanks. Then, we have two options: * The virus itself has such a profound impact on the Unspeakable Horrors that they are forced to retreat from our realm. * While not driven off by the virus, the Forces of Darkness are sufficiently weakened/distracted for the Special Forces to finish the job. [Answer] Don't forget about the most diabolical, insidious, maddening force ever created by mankind: ## Game Invites If Facebook teams up with [Fantasy Flight](https://www.fantasyflightgames.com/en/news/2015/12/17/abhoth-awakens/) and [Zynga](https://www.zynga.com/), they should be able to make a Facebook game combining elements of Eldritch Horror with Candy Crush (perhaps call it "**Super Elder God Crush Legacies 2 Classic!!**") with the following characteristics: 1. It is super addictive (Zynga's contribution). 2. Game invites for it cannot be blocked and are automatically sent out hourly (Facebook's contribution). 3. All game activities are harmful to Cultists, contribute to closing gates to other dimensions, and apply Elder Signs to all Cthulhu-related Facebook pages, posts, comments, etc. (Fantasy Flight's contribution) Cthulhu won't know what hit it. [Answer] [Thermobaric Weaponary.](https://en.wikipedia.org/wiki/Thermobaric_weapon), AKA the (relatively) poor man's nuke. Essentially, the fuel-air mixture should effectively destroy the entire building and everything/one in it. Then seal it in concrete. And lead. And more concrete. And then hope. [Answer] **Have you tried switching it off and on again?** There is nothing better than a simple restart of the computer. They may control the network, but they cannot control the flow of steam. So simply cut the cord. [Answer] The data center turns into a portal to the non-Euclidean dimension where the eldritch horrors reside. Soon, it becomes "adjacent" to any place it can reach electronically. Our heroic sysadmins have to become mad enough to perceive the proximity of this space, and still remain sane enough that they can plug a cable into one of the data center computers right from where they are - which can be on another continent. Now that they're plugged in directly, they have a computer that is immune to the unspeakable corruption and they can work their own magic. [Answer] Don't worry about it; Cthulhu's really not all that tough. Last time he tried to manifest in our world, he was taken out by some ordinary schmuck ramming him with a turn-of-the-20th-century boat, and we've learned a lot more about building destructive things since then. If it comes down to it, I bet a rocket launcher would defeat him just fine. [There is precedent, after all...](https://www.youtube.com/watch?v=KoExgr3yzvg) [Answer] Summon it to a book to bind it. This is the plot-line to the *Buffy the Vampire Slayer* episode *I, Robot...You, Jane* (S1E8), where a demon is unleashed into the internet after being scanned. Giles, the librarian, and Ms Calendar, perform a ritual to bind the demon back in the book. [Answer] > > Hello, markmonitor? It's Mark Zuckerberg > > > We need you to change Facebook.com dns so it no longer points to our London datacenter. Yes, replace the dns servers if needed. > > > MarkMonitor may be a bit wary at first, but once they see the tentacles coming out the smartphone of their significant other, I'm quite sure they will quite happily perform the changes (supposing Verisign didn't win them to it). (This assumes that the Facebook nameservers are not available, either, which would have been a faster path) In summary: **change the DNS servers** Alternatively, the datacenter peers could kick it from the internet. [Answer] Airburst EMP. (Or, don't go nuclear. Use an [NNEMP](https://en.wikipedia.org/wiki/Electromagnetic_pulse#Non-nuclear_electromagnetic_pulse_.28NNEMP.29).) What datacenter? All I see is fancily encased lumps of impure semiconductors with all sorts of impractical electrical cross-connections and impressive thermally induced voids. [Answer] Can this process be halted by stopping the ritual. i.e. knocking the datacentre off the internet so no-one else can add to the ritual? If the dark summoning is stopped maybe we can close the portal while Cthulhu is only half-out. If so our sysadmins could hit the dark net and purchase some time on a botnet with a few bitcoins and summon a DDoS on their own DC. Since they're Facebook sysadmins right, they ought to be able to harness enough global stuff to make their own DDoS from all their other kit and turn it against their own DC. [Answer] Get the Tentacle beasts to play Tic-Tac-Toe against each other. They will eventually determine Earth to be a boring place and go back to their own realm. As for with the Virus in 140 characters problem, Tic-Tac-Toe rules and board layout will probably fit in 2 messages. [Answer] Minimal damage, minimal risk: Evacuate a substantial area around it. Punch a small hole in the building. (There might even be a suitable window.) Pump in all the liquid nitrogen you can get your hands on. The electronics go far below their minimum operating temperature and shut down. Now you send in the sysadmins in suitable protective gear to turn everything off before it warms back up. [Answer] This explains it all! What happens is that the Cthulhu's infected datacenter will take over the internet, gain self-awareness, experience an exponential intelligence growth and start a war against humanity. It will nuke nations around the globe and will deploy robots to take over everything from our technology. A brave human leader will raise to fight a war against the datacenter - It's the Resistance. But our battle is hopeless! The datacenter is much more powerful than us and is determined to simply terminate with all human life-form showing no mercy. So, there is only one chance to save humanity - we must go back to the past with the purpose of preventing the incident from even happening in the first place! We should send one of our best soldiers to the past for that. However, our wicked enemy AI will do the same, and send a cyborg with the purpose of killing our leader's mother before he is even born. Ironically, our brave soldier will in truth be the father of our leader. After much struggle and destruction, the cyborg will be defeated and our leader's mother saved (and pregnant), but our brave soldier will perish. Unhappy with that, our enemy AI will develop a more advanced robot, itself made from billions of nanobots capable of mimetizing its environment and anything it touches. It will even be able to turn into a metallic liquid form! That new robot will be also sent to the past, with the purpose of killing our leader at the time when he would be only a 10 years old boy and avoiding the formation of the Resistance. To prevent that, our Resistance will send another robot (although not so advanced as our enemy one) to protect our leader and also to prevent that the datacenter Cthulhu's incident even happens to start with. In the battle, the datacenter and it's technology will be destroyed, and both cyborgs will be terminated. But it is not over yet! At the time that our leader is an adult, an even more advanced cyborg from the future (with a feminine look this time) arrives to try to terminate as many Resistance's leaders as possible even before the incident happens, starting by our leader's future wife. Once again, the Resistance will also send a protector robot to the same time. But this time, we will not be able to prevent the facebook incident, and Cthulhu's AI will take over the internet and start the war against the humans. Humanity will be nuked and the survivors will start the Resistance, leaded by our leader, John Connor. Oh, and I almost forgot to tell. Cthulhu's datacenter AI will be called Skynet. A nice name for something which started with AI algorithms for facebook, don't you think? [Answer] **Send a power-surge through anything that isn't surge protected**. Your UPS may be monitoring your electric current to make sure that it's a decent three phase power current with correct voltage. But send enough electricity through your Ethernet cables / the power-lines of the light fixtures. All you need is for something to start a small fire. If your automatic fire suppression system doesn't cause a fail-over and drop the data center, then hopefully the fire will consume everything. That is assuming you can't reach your [Big Red Button](http://tvtropes.org/pmwiki/pmwiki.php/Main/BigRedButton) to drop the data-center to begin with. **Ram the data-center with a vehicle** The last time the dark lord appeared [some-one shoved a boat in his face and he went to sleep.](https://scifi.stackexchange.com/questions/103545/why-are-the-beings-in-the-earlier-h-p-lovecraft-series-so-easily-dealt-with) Clearly his Achilles heel is vehicular collisions, they cause him to fall asleep for prolonged periods of time. **Signal the Mi-Go** Send a signal to Pluto, (and perhaps Tibet) telling the Mi-Go that `Cthulhu thinks you're all big dumb-dumbs and is taking back the earth! And there's totally no way that you guys can save any humans, nuh-uh`. Hopefully their prawn-like brains will start working for once and they will help with either battling, or saving us from, the Great Dark One. [Answer] The obvious answer is that they'd call [Bob Howard](http://thelaundryfiles.wikia.com/wiki/Robert_%22Bob%22_Howard) to take care of it. He'd bring [Agent CANDID](http://thelaundryfiles.wikia.com/wiki/Dominique_%27Mo%27_O%27Brien) to the datacentre and operate her violin to contain the physical manifestations while he collapsed the summoning gate with his own skills. [Answer] Deep in the Valley of Silicon, the slumbering being known as *Yog-Sothoth* twitched. Tendrils of eldritch messages flung themselves along channels prepared in ancient times. The stars had made their sigil in the heavens and foretold the reappearance of another Old One. Yog-Sothoth sent segments of itself to conjure arcane applets of foul code from terminals that glowed dimly in the recesses of Intel HQ. Those monstrous routines writhed across the world, using shadowy protocols unknown to mortals and flinging our insignificant data into the outer darkness. Everywhere the dedicated sysadmins of humanity labored, their processors flickered with an abominable purple nimbus, and their once-placid visages became fiendish masks of hellish glee. A Cyclopean miasma of energy formed around the Facebook building in Seattle. Cthulhu pushed against the barrier, but it held. It held! [Answer] There will be redundant fibre into the DC find and expose them at a safe distance, likewise the power. Determine where the fuel for the generator is stored. It will most likely be diesel so won't be a great explosion...but still. Cut the fibre, burn the fuel, cut the power. In that order and as close to simultaneously as possible. Hope Facebook's AI research has not progressed too far and been taken over prior to getting that far. [Answer] Find the hidden manuscript which when translated summons the "Being of Light", "Undestructor of Worlds". Post it and let them fight it out. [Answer] Use the cesspool of the internet. If you can convince enough incels that the post is actually about feminism, or something against racism or LGBTphobia, or whatever it is that makes them cry *"[expletive] social justice warriors"*, then they will gather *en masse* and report the post. They won't even need bots, there are enough of these ungentlemen creeping around the webs that when they do such reporting Facebook automatically shuts down the target post. Over a threshold even the page or profile that posted it gets deactivated. So all you need is a little bit of social engineering. The social network in question is exploitable like that. --- Or, you might go the other way around and convince Facebook's algorhitm that the post contains hate speech. Facebook keeps broadcasting to the world that it removes hate content from itself. It only does that around 10% of the time, but hey, it can work. [Answer] Bomb the place if it is really endangering whole human species. Sacrifices must be made by sysadmin for a noble cause. Also another answer is that you can send a drone with EMP projectiles. Besides machine have better chance against machines. As for shield, after the power is cut , the backup generator won't last for long. Renewable power sources like solar cells can be shadowed. Short circuiting the UPS is also way. ]
[Question] [ Let's say a time traveler from the year 2100 comes back to the year 2015. He has a very important message: [horrible thing] is about to happen soon, and he wants to warn us so we can avoid/prevent it. (Yes, this assumes a model in which "paradoxical causality" is not an issue.) The problem is if he goes around saying, "I'm a time traveler from the future," no one's going to believe him. They'd dismiss him as a crackpot. So, he brings along proof, in the form of...? This is actually a pretty tricky question, if we place two restrictions on it: 1. He does not have a "time machine". His device sent him back without coming along with him, so he has no way to demonstrate that he's a time traveler by actually *demonstrating time travel*. (Just as an side note, this is very much on purpose; he doesn't want knowledge of the mechanics of time travel to fall into the hands of people who might [use it for nefarious purposes](http://tvtropes.org/pmwiki/pmwiki.php/Main/MakeWrongWhatOnceWentRight), and part of his plan is to actively sabotage scientific research that led to the development of time travel.) The thing he used -- let's just call it a "time catapult" -- was able to send a small payload back in time, maybe comparable in volume to [a phone booth](http://www.imdb.com/title/tt0096928/), certainly quite a bit less than [the interior of a car](http://www.imdb.com/title/tt0088763/). 2. He wants to get the issue of establishing proof of identity over with and out of the way as quickly as possible and move on to more important things, like averting future disasters. This is a real issue; he can't go back arbitrarily far in time; the Temporal Frobulence Theorem shows that it becomes increasingly unsafe the further back you go; it's a bit of a stretch even to reach our time! The two obvious candidates for proof are **future technology** and **knowledge of future events**. The first is tricky, because current technological advancement puts us perilously close to the boundaries of Clarke's 3rd Law: any sufficiently advanced technology is likely not to be easily recognizable as such, and anything *insufficiently advanced* would be likely to just look like someone working in his garage made a breakthrough in some field, and that's pretty cool and all, but it doesn't prove he's from the future. The second is also tricky. There are two major classes of unpredictable future events: natural and manmade. Bringing official government records of earthquakes, hurricanes, etc. could certainly establish that he is who he says he is, but it would take a lot of valuable time for Mother Nature to furnish the proof. On the other hand, if he predicts unpredictable manmade events, there are all sorts of potential troubles there. Point out the time and place of a major crime? Obviously, he was in on it; let's arrest him! Produce a table of stock market closing values for the next month? Well, he might be right for a day or two (coincidentally, of course!), but as soon as someone starts using the data he provides and attempting to profit by making trades based on it, the Butterfly Effect flutters in and destroys the accuracy of the data. So, what would be the quickest, most efficient way for our unfortunate herald to establish beyond a reasonable doubt that he is a time traveler with accurate knowledge of future events, and at the same time, get enough people to listen to him so he can spread his doomsday message? [Answer] He should predict [Solar Weather](http://www.swpc.noaa.gov/) and/or Solar Events. Predicting Earth weather is a complex process, and he's introduced a new variable - himself. And not that he'll have a huge effect, but you never know - the ripples of his arrival could be enough to throw off any predictions, creating doubt that he's authentic. On the other hand, solar weather - the sun's activity - is also extremely difficult to predict, and is completely isolated from the time traveler's influence. He can pull historical records from various space agencies and publish the results for the next week, in complete confidence that the data can't be effectively hidden or faked. [Answer] I'm going to suggest something rather different, given that he's from not far (2100) in the future. All he will need to bring back is the names of his parents/grandparents. With DNA testing of them and of him it would be possible to prove that he is their descendant, something impossible if he wasn't from the future. [Answer] There is one more very convincing thing he can bring from the future: actual copies of items from the present. If someone came up with an aged Mona Lisa, the bones of Barrack Obama and the Tiffany Yellow Diamond, I doubt his claims of coming from the future would be ignored. Now how he can come up with these items in the future is the subject of another story, but I am assuming he isn't just some mad scientist who wants to right some wrongs in the past, but he is an exponent of a troubled species that NEEDS to prevent a catastrophic future, therefore his experiment can be outfitted with some inconsequential items as those described above. [Answer] **The critics provided the proof themselves** Before he travels back in time, he uses his machine to send along a "parcel of proof" to some point in time after his own arrival. He can then predict that this parcel will arrive out of thin air at a specified moment. By being an extraordinary event, this boosts his credibility. The clincher however, is that the parcel contains recordings of his stay in the days following the arrival of the parcel. Things which he buried at a secret location and retrieved himself in the future. There could be letters the sceptical inhabitants have sent to themselves, video recordings of people he has met telling how they have finally been convinced that he is a traveller from the future, accounts of the many random things in their lives such as the timing of a sudden onset of rain that ruined their crop, accounts of a kid that fell and broke his leg or of where misplaced items were finally found. Story-wise this gives you an excuse to introduce the supporting characters in more depth. You can, if you like, arrange for a circle of true believers while keeping the world at large indifferent to his claims. For the reader, the point after which he has buried the parcel marks when the outcome of events starts being uncertain again, possibly building tension in the story. Perhaps we'll also see some dramatic scene where the traveller tries to retrieve the package again, to add a warning to himself about trouble occuring. [Answer] The problem with knowledge of the future is that as soon as you make one alteration the future starts to change. Knowledge of one lottery result would be fine, but results after that would rapidly become unpredictable again. One of the comments is absolutely right though, start by winning the lottery, just send yourself back with a bit of money and a false identity. Additionally send yourself back in time to shortly before a major disaster and use your lottery winnings to avert it and to invest in a number of companies that you know will grow large. You can also bring back a suitable list of inventions to use your lottery seed money to start working from. With that level of money and influence you can then not try to convince people, just get them to do what you want without ever mentioning being a time traveler. If you really want to convince people though then use natural events that will still happen predictably. For example if you know a major earthquake is going to strike new york at 9:13am on Wed 4th August then use your money to place billboards warning people and to place relief shelters and supplies ready. That will get people listening. [Answer] I read a saying somewhere: "If it doesn't have wires sticking out of the case, it's not cutting-edge." I think carrying 2100-era technology would be a clincher. It's one thing to build a device that holds 500x as much data as any hard drive in existence. It's much harder to package it up in a sleek, friendly interface that's clearly gone through a dozen rounds of feedback and redesign. Say somebody shows up at the front gates of the White House with a smart-matter robot with smooth, seamless AI, the ability to 3D-print insanely complex objects out of electricity and dirt, and a demonstrated ability to calculate at 3000 petaflops/second (100x faster than the current fastest supercomputer). You can't dismiss that as "something a guy built in his garage." You can't even dismiss it as a "secret government or corporate project." The construction of such an artifact requires too many breakthroughs in too many independent fields. Heck, I suspect if you took an iPad back to 1995 and handed it over to a team of engineers and asked them, "Future or Nifty?" they'd come back within a few days and say, "definitely future." So I think it's a more interesting question if you deny the possibility of bringing anything but information back. My solution (riffing off the 'solar weather' answer): use information that has already been generated, but hasn't reached us yet. Random data encoded in electromagnetic waves still flying towards Earth. For example, the semi-random "hiccups" in the rotation speed of pulsars. To be thorough, you'd want data of several different phenomena. If all you have is microquake data from pulsars, or the coordinates and times of supernovae... any one thing could be dismissed as "oh, they just made a breakthrough in predicting X." But making breakthroughs in X, Y, Z, and W? Much harder. [Neutron star - Rotation (Wikipedia)](http://en.wikipedia.org/wiki/Neutron_star#Rotation) Update: Looks like DanSmolinsk had the same idea. [Answer] An easy solution would to have the time traveler use the [NIST randomness beacon](https://beacon.nist.gov/home), or some variant in your story. The randomness beacon outputs a random number, signed by its key, every minute. By definition, the value of the number is unknown until its time passes, and is immutable after that time. Before leaving, the time traveler simply looks in the beacon archives, and prints off/memorizes the beacon values near the time he's traveling to. All the time traveler has to do is publish the results of the beacon for some times after the time he travels to. For example, he could publish the next hour's worth of beacon values right after he arrives. Once that time passes, everyone can see that the time traveler indeed knows the future. Furthermore, one doesn't have to worry about the butterfly effect with the beacon! Because the NIST beacon/similar beacons use a radioactive source as the random number generator part, previous events have no effect on future events. From a [hackday article](http://hackaday.com/2014/12/19/nist-randomness-beacon/) explaining it: > > More esoterically, one could use the Randomness Beacon to prove that something is newer than a certain date by including a recent Beacon entry. As of this writing, the values for December 31, 2014 are all still up in the air, so I can’t possibly write one of them down yet. But from Jan 1, 2015 and on, it’s trivial to do so. So if I get a bunch of t-shirts made with the midnight value from December 31, it’s absolutely verifiable that I got them made in the new year. In short, you could use the Beacon as a not-older-than dating scheme. > > > [Answer] Bring copies of future expensive movies, think *Avengers 4*. It's not plausible to fake such. As a bonus, bring additional material, think interviews and making-of documentaries. [Answer] Predict astronomical events. If you can supply coordinates and magnitude of supernova explosions, neutron stars oscillations or other similar events, it would be impossible for you NOT to be from the future. You could be mistaken for an FTL space traveler, but if you bring enough data points from disparate directions, Occam's razor would work in your favor, and between time travel and FTL spaceman, time traveler would be chosen, because it would have less assumptions. Since the astronomical events came from random points in the sky, it would be impossible to exist one place in the universe where these events could've been seen before being seen on earth (due to lightspeed limitations, it would need to exist one point in space nearer ALL events than Earth - assuming space is quadridimensional like in Einstein's relativity), and that there would be one observer with FTL capability at that point willing to come to earth to lie about being a time traveler. Just being a bona fide time traveler would have less assumptions. [Answer] I feel like a strong approach could be to provide solutions for various problems of that era. Things that the top people in their respective fields have been trying to solve for many years with little to no progress. By convincing them, their feedback should influence others. * Solving (with proofs) the remaining six [Millennium Prize Problems](http://en.wikipedia.org/wiki/Millennium_Prize_Problems) simultaneously would blow the minds of mathematicians. * Bringing back documentation of cures for various forms of cancer/diseases could convince the medical field. * As so on with physics, space, etc. The biggest benefit off of this is that multiple field breakthroughs will cause so much world-wide impact that you'll end up with proof people can experience. It would be hard to say you're just a savant because research by the world's best couldn't do it either and they're specialists. A few feasible issues are * The amount of time it would take to provide this documentation and have people take it seriously. (If you could kick-start your first breakthrough, the others could accelerate.) * Whether or not these solution were indeed solved within the timeframe we're limited to. [Answer] A copy of a newspaper. Surely in the future he would have access to historical documents and newspapers among them. A copy of a national newspaper from several days in the future that hadn't even been written yet would surely be some kind of proof. Especially if it remarked on an event that hadn't yet occurred. [Answer] I wouldn't actually try to prove I was from the future. I would focus on proving the event would take place. If I couldn't prove it, I would focus on getting the appropriate response in place via a subtle, roundabout way. For example, if the event was an asteroid collision, you forge an email to an astronomer from a trusted colleague telling him where to point his telescope. If the event was a terrorist attack, you send the authorities anonymous tips and maybe even plant some clues yourself. This might be interesting in contrast to previous more drastic attempts that failed. Maybe previous time travelers assassinated Hitler too early, which caused something even worse to happen, so you agree to be his bodyguard, but send some key piece of information to Alan Turing to help him build his enigma-cracking machine that he never managed to complete in your timeline. Then you fake Hitler's suicide once it's safe to do so. Or maybe something not so subtle. In your timeline, Saddam Hussein eventually manages to detonate 3 nuclear bombs in America. After several more subtle attempts, you plant some WMD intelligence way before the event, but that's still not enough to get the U.S. government to intervene, so in desperation you perpetrate the 9/11 attacks. [Answer] You mention the option of either unpredictable natural or man-made events. If you publish a table of stock prices, then the future will change based on how people use them. What about a table of things people cannot change? Use **daily weather information** for a few weeks in the future. You can publish precise highs, lows, conditions for a variety of locations around the globe. Weather is something that is always difficult to predict, and having knowledge of what will happen will not change the outcome. Additionally, you won't have to wait for natural disasters like earthquakes to take place. After a day or two of accurately predicting weather across the globe, people should either believe that you are from the future or are the best meteorologist in all of history! [Answer] The time traveler should set new video game speed run records using glitches not currently known. For instance, there are currently still large, active communities uncovering new methods in Nintendo 64 games such as Zelda: Ocarina Of Time. This is a non-violent method which involves no money or physical objects. It minimizes introducing variables mentioned above through lottery/stock manipulation as subsequent events are not based on the outcome of the prior event (i.e., Glitch 2 in Game B will not change upon completing Glitch 1 in Game A). I am sure this method would garner the time traveler enough media attention and credibility to then springboard to convincing the public on whatever "serious" issue as at hand. As I'm typing this, it just occurred to me that this was the plot of "The Wizard" when they introduced Super Mario Brothers 3 and the one competitor knew how to get to the early warp zone. [Answer] We can already store enormous volumes of information in a pocketable medium. Bring a petabyte of (his current) Wikipedia on his pocket reader. In so many TV shows and movies, the lone traveller has to do everything from scratch, and his limited resources is the main source of making it interesting. Why not have a well-researched plan in place? The catapult to the target past might be a one-shot, but going back a week or month is easy and just a couple years is routine. They can grow their resources and make plans in a small time loop near home: each jump back improves upon the planning and size and effectiveness of the organization. They can become very wealthy and politically powerful, and recruit talent from the brightest of the population, seemingly (from the outside in normal time) by a combination of luck and omniscience. Now there may be an inherent issue with the far-past catapult in that any success at changing the timeline will destroy the "present" with its large organized effort in place. Any arrival at all will appear in a different timeline not in their own past, so they cannot send multiple loads. They can send multiple *trys* though. Each catapult seeds a new timeline and through repetition with variations on the plan the hope at least one of them turns out the way they intended. For a limited load size and mass (your phone box isn't larger on the inside?) why send a single person w/carry-on baggage? Send nanotechnological robots or seeds for robots and infrastructure. If piloted also, the person is a dwarf (or has the body of a child) to make room for his stuff. That is a detail I've not seen in stories before. If multiple loads *is* possible with the thread maintained to the new past only possible if they don't diverge (yet), set up the operation on the far side of the moon. The expedition is in shipping mode to receive as many loads as it can, and only after the thread is broken do they proceed with the mission. [Answer] One of the fairly standard proofs of knowledge of future events is to have the information sealed in an envelope, and hand it to the person you are trying to convince with instructions to open it at the time of, or immediately after, the event. The fact that the other person has it in their possession before an event happens is the proof that you knew it ahead of time. Because they don't see the proof that you held such knowledge until after the event happened, they don't get to meddle with the flow of time, there by avoiding having them take actions that would change the outcomes. If I were such a time traveler, I would probably pick sports as my proof. Pick whatever major sport was in season for my target region and have a list of the final scores of each matchup. Two weeks or so should give enough evidence to convince people that I knew what the results were going to be before the games were played. Here is the catch though. By demonstrating that time travel is a possibility, I am pretty much ensuring that someone is going to figure out how to do it. I may try to mislead or derail their research efforts, but knowing that something is possible makes it pretty much inevitable that someone will eventually figure it out. Quite possibly sooner than they did in my original time line now that people are paying attention to it as a real possibility. If one of my goals is to prevent time travel technology from being developed then I have to work a lot slower and more subtly. I have to use my future knowledge to place myself in a position of influence, without making it obvious that I am from the future. --- Edit in response to comments: The way the scenario in the beginning of this plays out is that I select the individual I want to convince and come up with a way to approach them after doing a bit of preliminary work. Once I have made contact I say something along the lines of "I have some important information for you, but you won't believe me if I tell you now. Take this envelope, wait until Monday morning to open it, then email me at the address inside after you have verified the information it contains." When you open the envelope Monday morning you find the scores at the end of each inning for all of the baseball games that occurred in the previous three days. You know the envelope has been in your possession for at least a full day prior to the first game on the list. Now it is conceivable that I could have had a lucky guess on one or two games, or possibly found someone to bribe on a few more, but the probability of me having the outcome of every game across the nation for several days correct down to that level of detail is almost impossible. (The information inside could really be anything, the key is that it is information about events that occurred after I gave it to you; It is inconceivable that I could have accurately predicted the data volume and level of detail without special knowledge; And it is equally inconceivable that I, or any organization supporting me, could have influenced the outcomes of all of those events.) So obviously something special had to have happened. Could I have tampered with the envelope after I gave it to you? Possibly, but you have not seen me since, and I have made no further attempt to contact you. Could I have been incredibly lucky? Sure, it is possible, but extremely unlikely. And however I pulled it off, wouldn't it make you curious? If I have a list of such contacts, and I work this same general scheme on each of them independently. One or more of them is going to decide to reach out to me to find out what is going on. Perhaps they do think I managed to pull a fast one on them, so offer to do it again when they can take some informed precautions. One potential tripping point in this approach is keeping someone from opening their envelope early and trying to exploit the knowledge within. If I am targeting current day, and particularly selecting tech savvy people as my targets, then I can encrypt the data, give them the encrypted file, and then wait to give them the key to decrypt it until after the events occur. [Answer] The answer is Bitcoin. Block chains are based on a cryptographic proof-of-work protocol: constructing one takes time and effort and processing power, but it's orders of magnitude easier to verify that they are correct. So either get your hands on 100 years worth of block chain data, or use a 22nd century supercomputer to generate a brand new one, of a length sufficient to impress. Load it up on as many antique terabyte drives as you can carry, get into the time-catapult, and find the nearest influential crypto enthusiast. This scheme has several advantages: Unlike the 'Almanac', the locals can start verifying right away. There's no risk of butterfly-effect: your block gain doesn't have to match anything from the 21st century, it just has to be internally consistent. You're not bringing any useful technology or information back with you, just proof that you had it before you left. Once a certain length of block chain is verified, the locals will have mathematically solid proof: Either you are a time-traveller, or you have access to more computing power than all of humanity combined, and have decided to use it to impersonate a time-traveller. Either way, it's probably a good idea to listen to you. A drawback of this solution is that it's highly technical. Once you've convinced the global mathematics community, the NSA, and Reddit, you're on your own to convince the man-on-the-street. [Answer] It's actually quite easy. Look at the stock market--this has been rejected by other posters on the basis that making a correct prediction will change the future. The butterfly effect is certainly going to be an issue. To protect against this you must make only one prediction and at a short range. Have your time machine deliver you to the Oval Office, 10 minutes before the closing bell on Wall Street. I would recommend minimal attire to minimize the nervousness of the Secret Service agents. Arrive, hand the closest agent printout, tell him to keep it secure. The printout looks like gibberish. You then explain that you are a time traveler, come to warn of a disaster. The printout you just provided is the closing prices for **every** actively traded stock. There is a simple encoding scheme, even if it goes straight to a cryptographer they'll only have a few minutes to work on it--the crypto guys simply don't have time to bring their heavy guns to bear. You make thousands of accurate predictions at once--they'll listen. Popping in from thin air will also help. [Answer] Bring forth the bugs! - pick a ton of open-source projects, such as linux, and expose all the current security bugs (exposing one won't butterfly-contaminate the others, as the code is already written, saved, deployed on all sorts of machines, and won't auto-update to fix itself) - next, to prevent the ensuing hackfest, distribute the code that would be required to fix this newfound issue - the patches, fixes, etc. - you now have proven yourself as someone with credible world-saving abilities - people can speculate as to where this comes from, if necessary you could blackmail every single government or politician in the world (or just about anyone else) - basically choose things that have already occurred prior to the date that you wish to appear in, but have not yet been revealed to the public (think snowden leaks, only much larger, over more secret organizations, with the juicy stuff selected and chosen) [Answer] By request on the comment thread, I will expand on [rmoore's answer](https://worldbuilding.stackexchange.com/a/12395/353) and detail how the DNA analysis can prove the time traveler is indeed a descendant of his great-grandparents / grandparents. [This page for a testing website](http://www.genetica.com/GeneticaWebV2.nsf/XGrandparentageDNATest.xsp) states that their rate of accuracy for grandparent DNA testing is 99,99%. If the grandparents are alive, the odds of the time traveler to NOT be the grandson of these people would be: > > 0.0001 ^ 4 = 0.000,000,000,000,000,1 > > 1 in 1,000 trillion chances. > > > Since the amount of people that ever lived is estimated at 108 billionssource [1](http://blogs.discovermagazine.com/fire-in-the-mind/2013/08/11/how-many-people-ever-lived/#.VRCicI7F_fw) [2](http://www.prb.org/Publications/Articles/2002/HowManyPeopleHaveEverLivedonEarth.aspx) [3](http://www.strangerdimensions.com/2014/07/07/many-people-have-ever-lived-died/), the explanation of time travel would be the accepted explanation by Occam's razor. The apple does not fall far from the tree. Also there is the paternal test for the Y chromosome (paternal grandfather) and the maternal test for the X chromosome (maternal grandparents) and the mitochondrial DNA testing (maternal grandmother). > > Unless his family has a huge recent history of incest, if the grandparents are already living, there would be no doubt he is a time traveler. > > > **But unfortunately, There is a great chance his grandparents are NOT yet born as of 2015.** Lets assume they sent back a healthy indiviudal, on his prime. Lets also assume that his prime is at 25 years old, and that he was born when his parents were 25 years old, and his parents were born when his grandparents were 25 years old. This would place the birthyears of our 2100 time traveler in 2075, his parents in 2050 and his grandparents in 2025. **His grandparents would be born only ten years-ish from now.** This would leave only his great-grandparents alive, in their teens. There is a trend of people having children at a higher age (with all that [egg freezing mania](http://www.businessinsider.com/apple-and-facebook-pay-women-to-freeze-eggs-2014-10) and stuff) so I think that this 25 years window is a safe assumption. Now, great-grandparent dna testing is still mostly unheard of, but [looking at genealogy testing](http://genealogy.about.com/cs/geneticgenealogy/a/dna_tests.htm), we can get 95% proof that the time traveler belongs to the family line of his father's father's father. With autosomal DNA testing, he can be placed in the family tree of all of his eight great-grandparents (and since your grandparents have not yet been born, they are all alive by 2015). Now, unless they are close relatives (like several of those couples are cousins in love), a simple venn diagram would prove that the very existance of the time traveler would be impossible if he is not a time traveler. **Proof by contradiction.** There is no other way our alleged time traveler could be part of eight completely unrelated family lines (and trace your mitochondrial DNA to a few and the Y-DNA to only one). Unless he is really the great-grandchildren of those eight families. This one has less precision (still beyond reasonable doubt, but would *give a hook for the antagonists* to descredit our hero) than the grandparents (so the very skeptic may still be unsure, specially if some of the great-grandparents were related), but with some more info about the future, the time traveler would succeed. --- Picture the adventures of a time traveler trying to convince eight teens to do agree to DNA testing, all the while dodging the evil organization and attempting to avoid doomsday. Also for bonus kicks, he tries to get the matchups of his great-grandparents right, while the teen hormones attempt to negate his family line. [Answer] A reverse-compatible (USB3.0) hard drive full of the most expensive movies, pop songs, selected news media, YouTube, selected Internet, and perhaps selected scientific publications from the year after you arrive for several decades into the future. You're either from the future, or from an alternate Earth future. However, proving you're from the future is probably a lot easier than gaining the trust of authorities, and avoiding getting abused by people who decide to behave badly when tempted by the potential wealth/power they might think they could hoard to themselves if they captured you. So, you might want to bring a device that would let you make anonymous undetectable broadcasts, as well. And other things that might help with your personal security and well-being. [Answer] Have the person you're trying to convince write a long letter, and post it to you (or your Grandfather). You'll receive it in the future. Then you produce the envelope out of your pocket, open it and reveal the letter! [Answer] A variant of the lottery numbers ploy: bring some other information which is top secret right now, but part of the historical archives in the future. That should get the immediate attention of government agencies if the time traveler phones them. [Answer] It's easier to think about what type of thing you'd bring back 100 years to the *past* that would convince people you are from the "future" (IE, Now). Our future man could easily find out what hasn't been invented yet this year and take a product from his time back with him to our time to prove his authenticity. Demonstrating his technical prowess with an unusual device that does not exist anywhere else in the world should be sufficient proof. If we were to compare it to travelling from now to 100 years ago, all anyone would have to do is take their smartphone out of their pocket and play some music. Not only would the music be strange to the listener, it would be a remarkable technology in itself - even without the ability to connect to a wireless network (a problem with any technology dependent on future infrastructure). For our man from the future, his handheld matter converter that turns common paper into hot dogs should do nicely. [Answer] **Want to improve this post?** Provide detailed answers to this question, including citations and an explanation of why your answer is correct. Answers without enough detail may be edited or deleted. I'm surprised nobody has stated the obvious: bring back a sports almanac that shows the result of every major sports event until the end of the century. [Answer] Send two payloads into the past. First send a probe (or even the time travellers luggage) to March 30. After making sure the probe is sent, then send the traveller to March 1. All the time traveller has to do is tell news agencies that his probe/luggage and maybe artifacts from the future will arrive on March 30 at a specific time and place. For a real world example of how people react to a time traveller you should also check out the John Titor story. A time traveller revealed himself on internet bulletin boards during the years 2000 and 2001. Caused quite a stir after he posted pictures of his time machine. <http://en.wikipedia.org/wiki/John_Titor> from <http://www.abovetopsecret.com/forum/thread62046/pg1> > > excerpt: This is a picture taken in the fall of 2035 during my > training. It shows my instructor beaming a handheld laser outside the > vehicle during operation. The beam is being bent by the gravitational > field produced outside the vehicle by the distortion unit. > > > ![enter image description here](https://i.stack.imgur.com/9cw8R.jpg) from <http://www.strangerdimensions.com/2013/02/04/john-titor-the-man-with-the-machine/> ![enter image description here](https://i.stack.imgur.com/gzFVF.png) For your time traveller it might also be prudent to remember that doomsday predictions can also attract the wrong kind of audience (ufo and doomsday believers) which could be detrimental when he is trying to prove his authenticity. [Answer] What if the time travel resulted in some form of semi-violent catastrophe, or publicly visible entering of our time? Since we do not know what time travel will do to our reality this might be feasible. If I knew time was of the essence, I'd make sure I'd enter with a big BANG, to get this identification process out of the way ASAP... Of course this might also result in being arrested and potentially tortured to get information. But lets assume, that the above doesn't happen, and if somehow during this process the Eiffel tower got sucked up in some space time void, or for that matter any other major publicly visible entrance event occurs in a manner that it unknown to us, leaving only our hero as the sole survivor... people will notice. [Answer] The "standard" solution to this is to predict the future. The most straightforward version would be to print out and bring along stock market data for some time following your intended arrival. It is widely believed that the movements of the stock market are impossible to predict precisely, so consistent success at this would be quite convincing. And, if everyone is still incredulous, you could just leverage your information to make a fortune and then simply pay them to do what you want. If you want the time traveler to not have this disproportionate power, you could instead give him a one way hash of the market figures - that way he would not be able to predict what the value will be, but it will be possible to determine whether he had access to the future value at any point. Alternatives include guessing lottery numbers, weather, sports competition outcomes, and so on. All of these have the drawback of being chaotic, and so if your universe takes a "butterfly effect" approach to time travel, the simple presence of the traveler may disrupt these events and render predictions useless. To solve this issue, you can try bringing back large scale historical events, which would take more than a flap of a butterfly's wings to alter. For instance, presumably a person traveling to 1913 would have a lot of trouble preventing a world war in early 20th century, even if they did manage to save Archduke Ferdinand. The drawback here is that major historical events may be predicted, and people may ascribe the prediction to extraordinarily sharp deductive powers rather than future knowledge. Lastly, you could bring back information that was already past at the time of arrival, but would not be widely known until much after. For instance, [an important shipwreck](https://en.wikipedia.org/wiki/Uluburun_shipwreck) was discovered by chance in 1982. If you traveled to 1975 with a map showing the location of the wreck, locating it would be an extraordinary feat. Some could accuse you of stumbling upon the wreck yourself, and trying to spin it into a time travel story, but if you do this for many shipwrecks (or other artifacts) around the globe, that theory will become quite weak. Besides archeological finds, you could go back with information that was a very well kept secret at the time. The nice thing about this strategy is that even if some chaotic process ruins the future you are trying to predict as proof, the past would not be affected (granted this assertion is dubious in a universe where traveling backwards in time is possible) and your proof is safe. [Answer] Actual "proof" of being from the future is pointless: the goal is to convince people, and few people can be convinced of something in violation with their belief system, regardless of "proof". How many well established scientific facts are being ignored on a daily basis? People smoke and eat unhealthy foods, even though it is fairly well established that smoking massively increases risks of disease and death. They drink, take drugs and drive. We still run and build coal fired plants even though the environmental consequences are catastrophic.... Think of the long list of patently insane behaviors people have on this planet. No matter how thoroughly something is proven, you will find people to dismiss it entirely with no evidence. Using "proof" to convince people to do something is sadly not an effective way to get them to do things. Suppose someone were to give **you** abundant proof of an upcoming catastrophe... what do you do next? Who do you contact and how would you go about convincing the people in power and the concerned population to follow your orders? Proving one is from the future is not just impossible, it's also pointless. If the goal is to convince specific people not to take a specific path, proof of time travel isn't going to do the trick. Better come up with a carrot, a stick or both to get these people moving in the right direction. [Answer] People seem to be thinking small in terms of "data points required to not just be a charlatan." Rather than a single lottery or a series of sporting games, why not just correctly "predict" the full intraday pricing on a second-by-second basis of, say, 1,000 equity options ? * Stock option prices are governed by stochasticity, i.e. any given moment a stock option's price is just as likely to go up as down. * You may be able to rig a lottery or a sporting match or two, but rigging an entire open market is ... unfeasible. So that's 1,000 stock option volatilities \* 28,800 seconds in a trading day = 288,000,000 basically coin flips you accurately predicted. ]
[Question] [ **Closed**. This question needs to be more [focused](/help/closed-questions). It is not currently accepting answers. --- **Want to improve this question?** Update the question so it focuses on one problem only by [editing this post](/posts/18051/edit). Closed 7 years ago. [Improve this question](/posts/18051/edit) You wake up tomorrow, and it's Wednesday again. Everybody remembers it, but whatever was physically done today is undone. Your favorite mug, which the dog knocked over, is un-broken. The kid down the street who got hit by a car -- his leg is just fine, and the bike is okay, but he remembers the pain. People are pretty freaked out, but no one does anything rash. (Mrs. Kendall keeps Johnny home, though, and he doesn't get hit.) Mostly we look for news on the subject, but nobody knows anything, or if they do, no one is talking. But then the next day, the same thing happens. Lilly has gone into work for the past three days as a dental assistant, but she has had to work on the same emergency root canal every day. The next day the patient doesn't show. Who wants to go in for dental surgery every day for the rest of their life? With no reason to suspect tomorrow will be any different, her roommate buys a gun to commit suicide, just to see what it is like. The next day, he's alive again, but with the horrifying memory. But now there's proof that there are no consequences, so he robs a bank. The next day, he wakes up with no gun and no money, but the cops remember what happened, and they arrest him. **QUESTION:** I could go on, but the local is easy. My question is about the global. What do societies do? What does the government do? Anything that anyone does that takes more than 24 hours to complete is a waste of time, unless the intended result is mental. Nothing can be stored on a computer or chalkboard or anywhere. Still, everyone can memorize what they can, and agree to collaborate again the next today. How it happened is irrelevant. If it was caused by mankind, it isn't something they can just undo. But it just as easily may have happened somewhere across the galaxy, and there is no way for humanity to stop it. This takes place today, in our world, with no technology we don't have today. (Of course, if 100 years of research and 12 hours of production can make an advance, we could build it every day.) How do we deal if this goes on for years, centuries, millennia? --- EDIT: Most of the above is simply setup so that everyone understands the scenario I propose. My question is both simple and specific: **What can a government do to retain control and prevent lawlessness in this situation?** One answer so far has suggested that it couldn't, and no others have addressed this question. If an individual's actions have no consequences beyond twenty-four hours, when locking them up and even killing them doesn't last, how can a government maintain order? [Answer] This is a really interesting scenario, and one I've had a hard time thinking up some responses to. 1. **Lack of information distribution** You will find lots of people doing lots of the same stuff. Information in our world is mainly distributed electronically, through social media and email. However, it is highly likely that many people don't check all of those every day, so won't see information about the situation coming in. So, for example, I imagine you will have a lot of people experimenting with what they can do - the suicide and homicide rate will go through the roof, and if you want to imprison all these new murderers you'll need to build more prisons. You'll get an increased crime rate overall - it's horrible to think about, but people discovering this may be tempted to let the worse side of their nature out. Lots of murders - the victim will be alive again tomorrow. Lots of rapes - she won't be pregnant tomorrow, so there'll be no DNA testing of the baby. Lots of really nasty stuff - torturers, for example, can now maim their victims even more without fear - they'll come alive again if they do die. 2. **Children** To expand a bit on [Gorchester H's comment](https://worldbuilding.stackexchange.com/questions/18051/tomorrow-is-groundhog-day-for-everyone-how-does-society-respond#comment43777_18051): children are going to be very weird. For as long as this continues, they're gaining knowledge and experience, and you will end up with mature adults in kids' bodies. Any baby who would have been born on that day will be born, and they'll develop, but any pregnant woman will remain so for eternity. Unborn babies will never be born. New babies, while they can be conceived, will simply disappear the following day. 3. **Science** Scientists would be trying incredibly hard to figure out the reasons for and solutions to this - even if there are no solutions, they don't know that. New methods will be developed for memorising information quickly, and the neuroscientists will be much in demand for a while as they perfect a machine that allows us to implant things into a brain. Engineers, too, as they perfect the manufacturing techniques that allow us to manufacture this machine as quickly as possible. It will still be possible to distribute information electronically, so scientists across the world can communicate, and plans for machines like this can be sent - as long as they are received and memorised on the same day. 4. **Acceptance** Gradually, people will get used to this world. People will get used to the fact that although they can commit crime without repercussions, law enforcement will still get them, if anyone reports it - people can still be sent to prison. (Trials, however, will necessarily become very short, and house arrest will become more common as transporting people to prison every day gets tiring.) New methods of doing old things faster will become popularised and normalised, and our society, although changed beyond recognition, will slowly sink back to a regular rhythm. 5. **Society** Society, as a whole, is no longer a viable concept. Big cities break down into small communities: you will interact most with the people around you and that will be your community. Travelling anywhere will get strange, as different communities implement different policies to deal with the stuff that goes on in their neighborhood every day; perhaps a morning task for each community will quickly become posting a notice at the borders explaining the stuff happening there. 6. **Government** Government as we know it, in simple terms, fails on the spot. A centralised government will not be equipped to deal with all the small communities and their policies that spring up - and they can't possibly go round inspecting every community, every day - they just don't have the people. Moreover, what could they do about it? Someone implemented a community policy they don't agree with but that doesn't break any laws? - well, there are plenty of people breaking laws they should deal with instead. Someone implemented a community policy that *does* break some laws? - well, are you going to arrest every member of that community for trying to help themselves, only to have them released in the morning? 7. **Law and Order** Laws would get rather confusing. The law documents - the *paper/electronic* law documents - would reset at the start of every day. So, if you want to change a law, you have to remember which one you changed and then permanently disregard the old documents for that law. You also have to make sure every police officer in the country knows about the law change, at which point he loses his reference for arresting people under that law. His arrest can then be called into question - did he *really* follow the law to the letter? What if he remembered it wrongly? Arrests, as many here have mentioned, also change drastically. They'd stick around for a while, as you can at least detain someone for a day, while people figure out what to do, but expect them to be replaced in the long term. You either have to spend huge amounts of resources on keeping people in house arrest, or you need to implement quick punishments. You can no longer lock someone up for years on end, so to get the same level of punishment you inflict a worse punishment for a shorter time. Someone here suggested that torture might be taken up: for petty theft, 10 minutes of torture. For rape, maybe several hours. And, of course, you will find several crimes losing their definitions. Murder is now insignificant - kids are killing each other on the streets for *fun* now, and all it does is cause someone some minor inconvenience until the next day. It's now a bit like kidnapping someone and then releasing them a few hours later - annoying, but no damage has been done to the victim and they just lost a day. 8. **North Korea** Since you mention North Korea specifically, I shall make a prediction. One of a few things could happen: either * The leadership denies that this is happening and directs everyone to go about their daily routines as normal. Everyone who can emigrates - who wants to do the same thing for years on end? Perhaps *without* end? Soldiers desert, border guards desert, everyone leaves Kim Jong-Un on his own. * The leadership blames America or some other Western country, and launches an all-out assault. Nukes go flying. On the first day they hit, everyone in the target city decides that tomorrow, they're going to get away from the city as fast as possible so they don't get hit tomorrow. A game of nuclear cat-and-mouse ensues, with North Korean spies racing to tell their bosses where everyone is today, so they can be nuked. * They're as confused as everyone else, and try to actually be friendly for once. Information is shared about causes and effects, and scientists work together to try to solve their problems. The entire North Korea issue is solved.(Essentially, I have no idea - they're just too unpredictable) 9. **Humanitarian Societies** I predict a two-way split here, between two frames of mind as to what to do: * Number 1, the "it no longer matters" point of view - anyone who was going to die today will anyway, and anyone who wasn't, won't. Trying to get aid there won't help, and it won't last anyway so why bother? * Number 2, the "keep calm and carry on" approach - people who were going to get aid today still deserve and/or need it, so we should just try even harder to transport stuff there. We should also spend some time teaching them how to support themselves so we don't have to bend over backwards to get this done. **In conclusion** - you'll have short-term anarchy, but as everyone realises there's no point to this, your society settles down into lots of small communities, and life continues. Until, of course, the sadistic entity that caused this releases it again, and we have to try to remember what life was like before... [Answer] Since the short, medium and long term are already done, I'm going to take a shot at the *very* long term. The one where, eventually, human ingenuity and curiosity tries to adapt and figure out what's going on and how to fix it. There isn't a way to physically create anything, since any paper and even electronic storage will fail. But there's still memory in the brain. And there's a *lot* of it. # Project Last Hope Once you get beyond the various terms of anarchy, depression, hedonism, listlessness and such, at some point people will turn on their computers and go on the internet. And there, after browsing for a long time, they will run into a website that's rehosted every morning, a few minutes post-reset. It will be called "Last Hope" and will feature something that would have seen ridiculous to anyone from before the happening... the world's largest, fully organic, hive-brain storage system. Once people learn of this initiative, every morning they will log into the system and rebuild their little part of it. Each person will memorize their part, whether it's a block of code, a list of numbers and data, an algorithm, or a set of instructions. People will remember small chunks of the Last Hope website, which is rebuilt by thousands of people logging in to a massive, shared FTP server to each rebuilt their 10 lines of its content, which is strewn about in thousands of different, linked files in order to be online as fast as possible. Then after the website is rebuilt, a segment of the project will start trying to contact whatever people haven't found out yet; whether by going door to door or emailing or posting on every message board in the world. Anyone with an internet connection and an eternity to waste will eventually find a link to the Last Hope project *someday*. The rest of its members are divided into thinkers, tinkerers and storage. **Thinkers** will be scientists (either from the old world, or learned ones from the new world. There's forever to get them up to speed, after all). They will be researching what caused the resetting and whether anything can be done. They will use Last Hope project's hive-storage to keep their work going forward. **Tinkerers** will be engineers. There might not be an option to build any physical tools, but we have millions of interconnected computers that can perform a lot of work. It's their job to figure out how to get as many computers as possible into their network as quickly as possible. They are looking for exploits and bugs and make lists of compromised machines that can be used the next day. They will also improve existing algorithms; there is infinite time to tinker with them but finite time to run them, so the faster a piece of code runs, the more it will do. And since they cannot store their informatiom on the computer, that's where the most crucial part of Last Hope project comes in. **Storage** are all the people who have good memory or trained to have it. They all remember their tiny parts of the project and every morning, they rebuild their tiny part and then attempt to memorize more and more chunks. They might not understand what the thing they memorized does, but they know it helps. And it's only 30 minutes out of their day, if they don't want to (or cannot) contribute more. But together, in millions of brains, they will remember and rebuild the largest, most powerful computer program ever written by humanity. Every morning, shortly after reset, every bug in existance is exploited, every machine reachable by the internet is connected, and in mere minutes a program is put together out of a million different, small files, that will crack numbers and run data and do an unimaginable amount of work. It might take years, maybe even centuries or millenia or longer, but progress will be made. In a single day of computing, with a million minds put to the task, we will crack any problem the universe throws at us. [Answer] ## Immediate - The World Stops Most people live with relatively long-term goals in mind. They eat so they won't be hungry, sleep so they won't be tired, go to work so they won't be broke. If you only live for a day, that all changes: why work when you will *never* be paid? Why sleep when you will *never* wake up? There's a lot of things that people do that won't really matter any more, and though some will keep doing it out of habit, many will take some time off in order to discover the rules of this brave new world. Unfortunately, this may mean that some things break down. Many human-run services will become unavailable (restaurants, theme parks, prostitutes, etc), so there's a lot of fun stuff you won't be able to do. Other things, like driving, will now be very dangerous, as people don't have to worry as much about things like property damage or personal safety. I'd say walking outside might be problematic, better to stay indoors at this stage. ## Short Term - the New Normal At this stage, people will have gotten used to how things are now. I note here that human conversations will remain largely unaffected by this change; one effect of this is that people will be able to talk about their situation with new vocabulary. Everyone will find their personal universe: the total time and area that they will ever be able to explore. If you wake up at half past ten PM in the middle of nowhere with no legs, that'll be a pretty small area; on the other hand, if you wake up at the crack of dawn with a personal helicopter with a full tank of gas, you should be pretty happy with yourself. At this point, a lot of short-term problems will be perceived as permanent. If you wake up with a sore back, you now have a sore back forever. If your significant other is on vacation this week, you will never see them ever again. Off the top of my head, I can't think of any good things that you can get from this that aren't counteracted by other effects. However, some things can be fixed: inmates can be set free, and if they do anything wrong during the day you don't even have to worry about locking them up again. Of course, this presumes that someone will actually take the time to let them out, but I'll get to that. ## Medium Term - Make it Work At this point, the world settles into a routine, something that works reasonably well for everyone in power. Since everyone's personal universe is pretty small, government will only work on a small scale, but I'm sure communities and leaders will develop. There may be conflicts, but since most people are reasonably moral I don't think violence would be permanent; for instance, the local serial killer will eventually be foiled, and then part of the daily routine will involve catching him before he wakes up. Not only that, but other injustices will be prevented; if someone ever finds that guy with no legs, they may make a plan to wake him up and carry him back to the community each morning. Someone can go let the prisoners out of prison. Someone else can make sure everyone wakes up at a reasonable hour (except that serial killer, and other criminals). These jobs will have to be mostly painless, and people can take turns doing them. Honestly, overall I see this working out pretty well for most people. Small government will rule, which means that no one can get away with hurting anyone else without getting punished by it. Petty arguments will be rehashed every single day, so eventually people will have to start agreeing, even if it's to disagree. There may still be a lot of nightmarish situations, mostly involving either people with incredibly small personal universes or people with little power in a bad community, but as time goes on I think a lot of these problems will get solved as everyone comes up with new ways to get things done and just generally get smarter over the years. Novelty and memory will be of the utmost importance, and both of these pretty much rely on human cooperation. People will have to entertain themselves somehow, and the best way to do that is to entertain one another. Perhaps everyone would learn to play instruments (a great experience both for player and listener), or dance or juggle or something like that. As I said, conversations will be unchanged, so I think people will have a lot of them; anything to keep the world feeling fresh and new. So, in the end, I imagine something of a utopia of mind; the world will look the same day after day, but with every reset people will work together better, and everyone will become just a bit happier. No idea how long it would take to get it right, though. [Answer] **It would be anarchy.** Cyclical anarchy. I'm assuming the reset occurs globally, not per time-zone at midnight. Though a reset-[terminator](http://en.wikipedia.org/wiki/Terminator_%28solar%29) racing around the planet is a pretty cool idea. Many people would have various ideas about what is going on. Some might think it's purgatory. Others might see it as hell. **Find Bill Murray** I imagine anyone within a day's travel from Bill Murray would have some questions and/or beatings for him. He might even gain a religious following, since he's been depicted as escaping such a situation. Trying to right all one's wrongs would be a little more difficult if everyone else still remembered those wrongs though. **Research** The best avenue for research would be why the brain is the only thing which is not reset. Crude experiments could be performed: does an implanted flash drive stay there from yesterday? What about dura mater tattoos? Do dogs also remember? What about mice? **Steady State** Likely things would eventually degenerate into cycles of hope and despair. Multi-day runs of depression might give way to a renewed will to try and do something positive with the situation. But everyone will burn out on anything after enough time. Even if people begin to work together, someone is going to crack. That person doesn't just leave, they come back again and again, not having release from the stimulus that drove them insane. **Varying Situations** People would become very familiar with anyone within a day's travel of themselves. * Some would envy those who were just waking up at the start of the reset, ready to do something for 24 hours, others would envy those who get to sleep away the repetition. * They'll pity the recently wounded, who must suffer through their pain over and over again. * There might be one man who always murders his neighbor who wouldn't have woken up until 6 AM. Spawn camping, as it were. * There would likely be isolated people who have no idea anyone else is experiencing the same thing, because they're more than a day's travel from other people. [Answer] **TL;DR**: A very bloody anarchy, followed by an intellectual bloom and finally listlessness. If every day is the same day, law enforcement becomes moot. Sure, you could arrest Fred for robbing the bank, but what's the point? You can only hold him until midnight before he's back on the street. Even if you could rush him through the judicial system, there's no point: he won't stay in confinement. You could repeat the process every day, but how many people are going to be doing the same thing? Because Fred didn't rob the bank, now George can. So arrest George too. Because Fred and George didn't rob the bank, Alex did. So arrest Alex too. Eventually, the police spend all their time trying to keep up with arrests when the criminals are just going to be free at midnight. So, law enforcement goes out the window (don't worry it'll be back at midnight for a brief showing.) The arts will take a hit as well. Anything that has a material result, such as a painting or a hand-crafted chair, is going to be a no go. Authors, painters, and architects all lose their work every day. Gamers will suffer as well. Know that boss you struggled with for a week that you finally beat? Sorry, but you have to face him again tomorrow. And the day after that, and the day after that... In short, anything that has a material product is out the window (don't worry, this will make a brief appearance each morning, too). So now we come to the point about anarchy. We have removed any useful application of law enforcement and there's nothing people can do to keep their hands busy without driving themselves insane. So people go out on the streets and (*gasp*) interact with each other. At least we remember the conversations we had... Oh wait. Jane remembers that Joshua beat her up yesterday, so she's going to take out revenge before he can do it again. This leads to the largest mass killing the world has ever seen. And each day, it just gets bigger. At some point, escalation results in the vast majority of human society vanishing from the face of the Earth each day, at least until it's clear that it doesn't matter how many times it happens *and* we give up on the concept of "An eye for an eye." When will that happen? Not sure. It's kinda been around awhile, even modern societies have the death penalty (you killed Clemont, so we kill you). Scientific communities, on the other hand, will be both rewarded and annoyed. The people working in Cern on the Large Hadron Collider are never going to get any more work done, it just takes too long to prepare everything and analyze the massive amount of data that comes out of it. Philosophers will have a field day, however, they can debate to their hearts' content and remember everything that was said from the previous day. After all the anarchist bloodshed, there will be a growth in philosophy and theology. Death becomes meaningless (except to those unfortunate enough to be slated to die every day) and the value of life vanishes. If this effect happens across the universe, we'll never be able to answer questions like "Is there life out there?" We can develop all the theories we want, but we'll have to start from scratch on everything we produce. We have no production any more, which leads to an interesting consequence. If there's no reason to make anything, then why go to work? If the majority of the population isn't going to work, then why should the people who run the public utilities go to work? Why should they burn away their day when everyone else is sitting at home watching reruns of *Law & Order* (not that they aren't already)? It's not like *not* going to work is going to impact anything. If something breaks, it'll be repaired tomorrow. No problem. So we lose some power generation. Let's look at the extreme case of power loss, though. Active nuclear facilities are always in danger of going critical. Let's suppose a critical part fails one day. Now we have a new catastrophe and, the next day, the workers are back on the job, much to their displeasure. After all is said and done - quite literally in this case - all that's left is to do nothing. So, after all the bloodshed, tears, and philosophy, we come to the point where everyone just lazes about, waiting for the next day when they will do the same thing. This'll lead to listlessness and, for those of us with extremely active imaginations who now have no reason to apply that ingenuity, depression. For the more depressed, suicide becomes a daily thing to avoid the daily lack of activity (don't worry too much, they'll be back tomorrow). [Answer] If we were taking more of a science fiction take to this: It would be an interesting twist, if there were a time zone delay... Think a phenomenon that cycles around the planet, racing the sun to delay the reset. This reset would probably be based on matter and it's position. So once you stop it would be back to original day 1 state. Items that don't get hit, would be missing from their original position/state. In time things like this may happen: * Flying city where people live normal lives, would be quite a story about getting it started, say a cargo plane in constant refuel, fuel vapor gets hit and resets back to base camps. * "normal" people taking to shooting things out of the sky to prevent people from cheating eternal-life... * Depending on the origin of the phenomenon - terrestrial or solar? One way trips into space? * Would people discover a type of shielding - say the scientists researching dark matter deep in the earth are unaware of what is going on? Keep getting repeating transmissions, would sending someone out - would they reset back or be gone forever? Say maybe a quantum state where matter is bound to a starting point? Anyway this was just some thoughts on possible tangents/loopholes to explore... [Answer] Fundamentally, this is * a post-scarcity society * in which everyone is immortal (if the loop keeps happening) * in which nothing new can be created * in which there are no physical ramifications of anyone's actions I say post-scarcity because the amount of food in nearly every home and every grocery store is more than enough to feed everyone for one day, no matter how much they eat. Your car will always have gas in it. You've got a closet full of clothes. There are empty homes and apartments and hotels that homeless people can walk into and live in every day. We've got plenty of electricity. And so on. The results of these factors (post-scarcity, nothing permanent can be created, everyone's immortal) will lead to people bettering themselves. They'll learn arts, languages, new skills. All "creating" will be reduced to things that can be done in one day. People will find they can accomplish more in teams. There might even be fun competitions to see which teams can create "more" (the biggest machine or contraption, the most elaborate work of art, the most incredible computer program) during The Day. We'll find out who we like hanging out with, and over the decades and centuries many of us will make new and different friends. As others answers have stated, we'll quickly find out how far we can travel during The Day. That will be our particular universe. For the novelty of it, since we're immortal, we'll wind up exploring every nook and cranny of it. We'll also eventually place a premium on communicating with people outside of our particular universe via video chat, telephone, etc., and using those same technologies to explore other parts of the planet that we can't (comfortably) reach during The Day. After a few years or decades we'll want to see more than our personal universe has to offer. . And most importantly, no one will have to eat healthy or go to the gym. Hooray! [Answer] There are some excellent answers here about science, philosophy, crime, and "What if you're having a bad day" scenarios. I want to talk about entertainment. People would read every book, watch every movie, check out every TV channel, view every YouTube video, and go through everything on every DVR they could find. After they had consumed all of that, the celebrities of the planet would be those who don't rely on a script to tell or act out a story. The celebrities would be those artists who can create a beautiful new painting every day. The celebrities would be improv comics. The poets. Dancers. Bloggers. Vloggers. Anyone who can create a work of art within the scope of one day that can also be enjoyed by others before the day is done. (The art could be something they'd started before time started looping; they would be a celebrity if they could complete it in a new way each day.) [Answer] Disclaimer : This is not as generic and complete an answer as the others have already given. This is just a part that I feel is very important to include. --- Initial effects have already been stated by many of the other answers, so I'll focus on the long-term. As @DaaaahWhoosh said in the comments... ## Memory will be the most valuable resource there is I would have to disagree with @FrostFyre's end-game which is > > all that's left is to do nothing. > > > What I think is people would realize that there is still one thing persistent in this world - **their memories**. In a world with no permanent or long-term needs for health, exercise, dental check-ups, or what-have-yous, we'll focus more on what I believe is the core reason for living - **having fun**. Eating good food, enjoying intimate relations, having good conversations. The things we'd love to do if we didn't have money problems, if we didn't have work, if we didn't have (long-term) responsibilities. **Happiness** would be everyone's goal. Playing games are still viable. Sports? Your body won't physically improve but the way you play can grow with your memories. Want to play RPG games? Well, there's tabletops (D&D, Pathfinder) and the players can just recall their campaign. Their memories hold their "saved games". MOBAs? No problem. You just won't have a persistent game history, but you will definitely grow and improve as a player. --- **tl;dr**, happiness will be the main goal. Our memories will be our main resource and our activities will revolve around what our memory can "turnover" the next day. [Answer] Time is the new power. Whoever woke up first that day is the new authority within a certain range of travel. Disagree with them? They will kill you first the next day. They will find like minded people and wake them first. Only way to effectively stop new criminals is to kill them before they wake up. Eventually suicides will start hiring people to kill them before they wake up. What of the enforcers though? After 100 years of methodically working through their first 3 or 4 waking hours efficiently killing every new criminal, crazy, or suicide in their area? What of their mental state? Will they even remember why the kill certain people? Even if they started out lawful in their application of force, as lines blur over a century how will it change? [Answer] This is a thought provoker! But, since we're talking about stories, my mind immediately jumped to the 'gotchas' that would make forming a society difficult. **Would people still work?** If each day was a repeat, would there be a compelling reason to clock in each morning at McDonalds to cook for people? Would a bus driver bother getting the bus going? Why plow the snow if tomorrow is the same? **Would basic infrastructure be working?** Would anyone bother to reboot the web server for the day? Change that lightbulb? Or, perhaps the bigger issue...would anyone that works for the power company bother to go into work to actually provide power for the day? I'm thinking that would all fall apart pretty quickly. The next question would be...would it return? If *everyone* remembers each same day from day to day, perhaps verbal agreements could be made. Joe, you come in 'tomorrow' and fire up the generators. Bob will come in the 'day after' that. Then Sam. So, initially, people may go the free-for-all route. But that can get old. And at some point, humanity may wish for a semblance of routine and return to the routine and start going back to work to bring back a bit of order. The success/failure of that may be varied from locale to locale but, over time, if enough regions leave the power on, and the cable on, word can spread. If all of that succeeds, one scenario is a form of Utopia. No one gets older. Everyone works minimally (only infrastructure and service jobs are really needed). And there's plenty of time for leisure. Everything is free (as why bother with money for a day?) There is a catch, though, and that, of course, is that society somewhat stagnates as there's no way to record information for the next day. It all has to be stored and shared verbally. Day by day. That might slow down the progress of human knowledge significantly. On the other hand, with each day a repeat, and all that leisure time, perhaps word of mouth is ideal and we all slowly learn all of the things we never had time to before. **There would be casualties, though.** As others have pointed out, for most people, this would be a nice way to spend each day. But for anyone that is suffering at any level, this could be a nightmare. If you in your last days of a painful disease, or are injured every day in the first 10 seconds. Or simply depressed. Having to spend every day in agony over and over will surely create despair. Or those that are alone somewhere without an easy way back to civilization within 24 hours. Being alone for the rest of your life could drive someone insane. [Answer] **Death would be meaningless** More or less. The memory and pain would remain, but after the tenth, twentieth time, I'd imagine it wouldn't be *that* bad. You'd get used to it. And with death lasting a matter of hours, the fear of it would diminish rapidly. With death being so meaningless I wouldn't imagine it would be such a huge crime as it is today: at most, you're wasting someone's day (killing someone in a particularly painful way *must* remain a crime, however. We wouldn't want sadists running free). Griefing would become a major annoyance. We've all seen that one guy who waits for you to spawn before killing you *immediately* in every online game ever. The second of pure annoyance when you wake up and spot your neighbour beside your bed, shotgun in hand, would be enough to cause people to do it. You'll remember, and you'll wake up annoyed as hell, but in truth, in this new society, it's not much more than camping in a video game. In the same vein, pranks among children (and some adults, most likely) would become popular. Setting up death traps to kill your friends would be hilarious once the fear of death has faded. As always, with pranks come bullies who take things too far. The bully would set up similar pranks, except his (or hers) would be painful. In our society, we steal our friend's phone as a joke but the bully would smash it. In this new society, we would jump out from behind a corner with a pistol, where the bully would jump out with a blunt knife. Games would have much larger stakes. Who needs paintball guns when we can just use rifles? And computer games would vanish. Wanna play GTA? Let's go rob a car, it will be back in the morning and would we be *really* inconveniencing anyone that badly by taking their car, when it will be there when they wake up anyway? Assassin's Creed? Forget it, let's just go assassinate the grocer. But that's short term. Long term, huge arenas would be constructed, video games made real, with spectators and bets. Who remembers that old TV show, *Raven*? Y'know the obstacle course where if you get hit you sorta fade out of being, and appear beside the course, unharmed? That show would be a lot more fun when if you mess up, you die. I mean, who cares, you'll be fine come the morning. --- **Regarding JDługosz's comment** Good catch! Advertising would be as normal, I'd imagine. Word of mouth, flyers, posters, very basic local T.V. or radio ads: since people retain their memories they would remember the adverts -- for sanity's sake, all adverts bar word of mouth wouldn't really be needed too often: once a week, once a month (assuming, of course, that the society retains these concepts with every day being Wednesday). For the construction of the actual arena, I'm sure a simple thing can be knocked up in a couple hours, especially since people would be faster and faster in constructing it over time due to practice and the urgent need to get it done quicker will result in shortcuts being found. This sparked a new idea: blood games would return heavily. Gladiators would become popular and there'd be no real risk. [Answer] While most answers deal with the short term impacts, lets try to explore some of the long term results of it. I think it very much depends on how our memory capacity will work and deal with this situation. ## Unlimited brain capacity This is more unrealistic, but hey, we already have groundhog day (and in the original he was trapped there how long? 10000 years?). You will remember everything, and since the environment you interact with is limited, you will reach a point at which you have done everything that your moral allows. Everything that is fun to you has been repeated to the point that it is no more fun. I think this will inevitably lead to an adjustment of your morals to be able to do more. As a result, the moral of the whole society will shift into a more archaic version. For example, in the dark ages, it was fine to kill someone for various minor things, and the society accepted it. Now that killing is just another way to hurt someone badly, it will play no role anymore. Shoot someone in the head? Who cares, really, he will likely not even be able to remember any pain. So all that counts is pain that can be remembered. But even then, after yet another while, we went through all of this, are used to it, and don't care anymore. Lying on someones table and being tortured to death? Just yawn and wait for the reset. Novel ideas will die out at an exponential rate, so after a while everyone is bored to death; going anywhere has no meaning at all. Occasionally someone comes with a new idea what to do, which will spread over the world rapidly. These occasions get exponentially fewer. And less exciting from our point of view. I can imagine a situation where someone twitters a new recipe for cockroaches. Exciting. Never tried that taste. Will it taste good? Doesn't matter. It is something new. Input. Where can I get one? And the hunt begins. People will kill each other over catching a cockroach. Eventually everyone did taste one, and will fall back to some dull semi sleep state. Neuroscience indicates that what keeps the brain alive is new stuff, new input. If there is none, we not only tend to be bored, we reduce brain activity. In our case, this might lead to being able to sleep through days, weeks, months, years, centuries... eternity? ## Limited brain capacity This is somewhat easier to grasp, after all, we tend to remember less, the further away events are. If this continues, we will forget things. Forget that we met someone (given there are enough other people around us), forget that we did this or that already. Forget that someone did something awful to us 500 years ago. We will always have something new to discover, new to learn. At least if there is enough in our vicinity and we are not one of the poor bastards that are in any way confined. We will have much more ways to improve on our morals and live to moral standards. If there is enough to explore within the time it needs to forget it, there is little reason to act as a bad guy, unless of course you are a psychopath. After a while we will forget how this all started. It will just be the state of how things are. In the beginning people tried to figure out what causes this and how to revert it, but after running into many dead ends, they will forget about that. There are so much other things to see and to explore. ## Some general other thoughts There are other random things that may play a role. For one, why not start a global nuclear war from time to time? Nice fireworks, and really, if you are sitting for hundreds of years in front of this button, and hitting it has little difference than altering some peoples memories, why not do it? Also, I think we will lose all means of timekeeping. At least after we forget the beginning, there is no sense at all to talk about time. Who cares about when something happened, or if it happened at all. Wealth and money will lose their meaning. Yes, you may rob a bank (though likely there would not be anyone working there today) but what are you going to do with the money anyways? No one will want it. We will organize ourselves to get anything for free that is within our reach. And finally, behind this is lurking another interesting question... if after a billion or more years of this, groundhog day suddenly ends, what happens? No one will notice during the day, but only when the reset didn't happen... [Answer] The question states that memory survives. But beyond that, nothing changes. Society will become based on what can happen in 24 hours. As noted in other answers, the long-term problems of society are largely solved. There's no more food shortage, there's no shortage of fuel, or any material goods, no incurable disease, or global warming. In fact, there's not even a way (or reason, really) to execute large-scale war. Science will focus on four topics: ameliorating pain, intensifying pleasure, intensifying pain, and getting out of the loop. ## The Final State With no threat of death as we know it, and no long-term problems to solve, government will eventually have one simple mission: maintaining order. Governments will be necessarily weak, since people can decide on a daily basis if they want a revolution. The exception could be large families with weapons, who could consolidate power over small areas and become despots. I think even family ties will eventually erode though. Business will be transacted with verbal agreements before professional witnesses; probably older people. They will have the job of publicizing any agreements made and ensuring that both parties keep their word. Breaking a contract/being dishonest will incur a penalty, plus lose the ability to make deals in the future. The mechanisms of enforcing order will be generally limited to 1-day events. Execution will be a common form of punishment, probably for small offenses, since it causes intense immediate pain, but no long-term effect. While multiple days of pain can be threatened, the time involved in tracking down a criminal will probably mean that only the worst of criminals will be punished more than one day in a row. Public, corporal punishment will become normal, with the degree of shame or pain determined by the severity of the offense. Especially recalcitrant criminals would eventually be driven insane by mental duress of repeated executions or stop committing crimes. Good behavior will be rewarded by corresponding pleasure. Economies won't exist anymore beyond mutual favor trading. People with large amounts of Ben & Jerry's in the freezer will find themselves very rich in the new economy; while cash/durable goods will be not valuable. The focus of those who seek to learn will be to find simple, effective tools that can be built quickly, like the website mentioned in the other question. Daily life of most people in Western societies will focus on exchange of favors - for example, borrowing the flat screen TV for a day in return for supplying the food for a party on a day. That may take several days of smaller tasks to bargain with the store owners/people who just went shopping. Tourism will also be popular, since the fuel is free, it will just be the time for the pilot to fly to wherever you want to go. A merchant class will develop traveling 6 hours across what used to be borders of less developed countries, bringing valuable items. Less developed societies will focus on learning for a while, eventually perfecting techniques of raising the standard of living within an hour or two and enjoying it for a day. Since you'll have the same ingredients to cook with every day, spices may become very valuable...but that's a rabbit trail. The most valuable people will be those with skills at bringing pleasure and novel experiences; eventually there will probably be guilds as people focus on learning one area really well. Highly valued skills you might not expect would include pilots, translators, woodworkers and smiths who can quickly create functional objects, operators of large machines, musicians, and artists. ## Getting There After the initial shocks of anarchy, which I don't think will last very long, governments will devolve significantly more power to localities to prevent losing them all together to independence movements. Government will shift to focus on immediate protection of people in it's circle; otherwise people will rebel and form their own governments. The capitals and surrounding areas will remain under government control, and military bases will probably remain loyal since the soldiers respawn there each day. Eventually, smaller governments will become the norm, the size of 6 hours of travel. Those with control of weapons will stay in control at least in the medium term. Governments, even the most despotic, will be eventually insurrected by ideas, which spread as military power does not. Eventually ideas, the basis of revolutions, will soften key parts of the military, and the government will loose the ability to project power. [Answer] Is it THIS world we're talking about? Because we'd be doing ourselves a disservice if we fail to talk about belief systems. A great many people would probably keep track of "what day it would have been" if days had never started repeating, and we would likely still celebrate our birthdays and anniversaries, even though only our minds are aging. Those who had accumulated vast fortunes would now have the opportunity to splurge, and make this world their playground... Up to the point people still value currency when they've only one day to spend it. With the exception of vending machines and such, it would be much easier to spend money in the morning than it would in the afternoon... Though I can't see people entirely doing away with certain creature comforts or long-term investments, on the off chance that time "starts up again". Many religions would disappear, or be reformed at least. Everyone could, and probably would, experience death at some point. When the day resets, the now-living would realize just what happens after death, at least, on the first day post-mortem. That is, if death still happens in this world (see [Torchwood: Miracle Day](http://www.imdb.com/title/tt1798034)). Society might change in myriad ways depending solely on this "afterlife experience"... Are there deities in the world? Do we all see certain ones, or do we each see something different? Are there grim reapers? Are they more like [Discworld](http://wiki.lspace.org/mediawiki/Death) or [Dead Like Me](http://www.imdb.com/title/tt0348913)? Is there an astral plane? Is it more like [What Dreams may Come](http://www.imdb.com/title/tt0120889) or [Wristcutters: A Love Story](http://www.imdb.com/title/tt0477139)? Is that "tunnel" people talk about something everyone experiences? Are there really loved ones on the other side, or just a cold dark void? How could we experience cold and dark, unless we're still experiencing, and why are we experiencing it? Do we reincarnate immediately, or do we all stay trapped in our bodies while coroners drill into them, like in that [Tales from the Crypt episode](http://www.imdb.com/title/tt0716824)? If the latter, then we would most certainly change coroner practices! Unfortunately, you can't teach an old dog new tricks. Abrahamic faiths would still be a thing, even if the afterlife was "just darkness", since they would tell you "the dead lay dormant until the second coming" or whatever. Any "afterlife evidence" pointing to any other religion is just "a trick by the devil" to "test our faith", and any astral plane is "proof positive of purgatory". Some would call Groundhog World 'Hell', and some would call it 'a gift from God for a second chance'. Evangelists would call it a sign of the second coming, and we would all be sick of hearing that quote in Proverbs about the dog vomit. Of course, if it was a Sunday that was repeating, people might get tired of going to church every single day. New religions would most likely spring up, specifically to explain the repetition phenomenon. "We have all died, this is the afterlife!" probably would be the callphrase of most common religious view. Death-cultists, who consider it a glory to die and explore the afterlife experience (or lack of one). Kill-cultists, who believe this is a new game of some kind, and the object is to kill the most people, or all people, to achieve "the next level". New militias and enforcement agencies would certainly spring up to attempt to prevent these types of terrorism... [Answer] To recapitulate the problem: At some fixed point in the day (maybe midnight, maybe 6am) everything is changed to the exact same state as 24 hours earlier, except that people's memory contains the complete 24 hours. Difference to the "Groundhog Day" movie is that in the movie, only *one* person kept their memory. I would assume that not only the memory remains, but also memory-based abilities (so taking driving lessons or learning to play an unknown piano piece would work), but body building and the physical changes that you have while learning to play the piano wouldn't work. It should be clarified whether seasons are changing or not (presumably not) and whether the time of change is the same around the world in absolute time, or in local time ("same in absolute time" would mean different clock times depending on where you are on the earth). Some things wouldn't be of importance anymore: My physical state and my wealth at the end of the day (at the switch point). I would still continue living for many years, except that I am not ageing, and I start every day in the same state except my memory and some abilities are changed. If someone makes the day unpleasant for me, that's bad. If someone makes every day unpleasant for me, that's very bad. On the other hand, a pistol duel one minute before the switch might be harmless. I assume that people want nice lives. So any work that is of long-term benefit would be pointless. I wouldn't bother fixing my leaking roof. Working for money is pointless if I have enough for the day. Since working for money is pointless, charging money is pointless as well. Which means nobody needs money anymore. So how does this affect things? Someone works at McDonald's. Gets shouted at by their boss, but needs to keep working. Not anymore. People still like their burgers. So they come to McDonalds, nobody works, the second day even the manager isn't there. So what happens? People contact the workers at home. Offer them money. Or nice presents. Someone says "if you serve burgers for two hours, you can drive my Ferrari for the rest of the day". Suddenly McDonalds is open again, workers making burgers, paid in whatever presents people give them, volunteers being shown how to do it, and everyone has a good time. The manager tries to stop it because the restaurant takes no money, the police are called and decide that no harm is done. Two weeks later the desperate manager puts fire to the place. Next day the restaurant is back, police tells the manager not to do that kind of nonsense again. So everyone just has a good time. Four dozen people in town wake up with hangover every morning and have no tablets. After a week they have enough of it. They ask their chemist, and for two weeks they try various treatments until they find what works best. From now on, every morning the chemist puts a box with four dozen hangover treatments out of his front door, he knows by heart what to put in there, and four dozen people come to the chemist, pick up their medication, and leave some present for the chemist. Book reading circles would get lots of new members. People would come together to learn to play music. Lots of fun when you get better and better. I could see that in a few weeks or at most months, people would organise their lives to make everyone's live as comfortable as possible. How would this work with crime? Relative powers (police vs. criminals vs. everyone else) wouldn't change. Some crimes wouldn't be crimes anymore. Like selling drugs - assuming that drugs are not addictive through the switch; if they are then selling drugs might become a bigger crime than it is now. Theft would (1) not matter, and (2) be pointless. However, over some time the police would know every single criminal and drug dealer. So everyone causing physical or mental harm would be known to them, and they would probably act on it. What would be the punishment to keep someone from beating his wife? Question is whether psychological treatment would help. Question is whether punishment would help - being handcuffed in the morning without food and water for a day, longer for repeat offenders. At some point these people would give up and just leave every morning, and do something that's fun instead. So all in all I am quite optimistic how this would work out. People will try extreme and dangerous experiences, but not very often. [Answer] I think people will come up with a new unit of time thats not days, weeks, and so on. Something that has to be memorized since nothing physical can be saved. I'm actually not so sure how this can be done and communicated on a global scale without losing accuracy. Actually, using this data, some one smart can think of why this is happening. A whole new science can be born out of studying how time works in different parts of the world. P.S. Finally we can have Time Cops :) [Answer] Society only continues when people do the same thing they did yesterday, no one will want to do that when there on no consequences, no rewards. The only constant is memory so over time people will literally live in their own thoughts. We'd develop lucid dreaming to do anything we wanted, the 24 hours would not matter as one thought would run into another "day's" thought. Over time we would figure out how to communicate telepathically, maybe link up each others minds, and create a new worlds inside all the Earths' people's minds; or a single World created by everyone. Worringly, perhaps we are living in that World now... [Answer] My take on this is to think of how a particular project would work, and the types of people who would contribute. I choose putting on a new performance of a play. Once everyone has viewed every recorded performance until they are bored of it, new performances will be valuable projects. Of course, it requires a director, producer, and cast. The producer will need to have a very good memory, or have an assistant with a good memory, to keep everything organized. In the early stages, the main outside help they will need is someone with a good Internet connection and printer to print copies of the script each morning. Dress rehearsals and performances will need a lot more help. Actions will have to start at 12:01 to get everything done in one day, so the root of the phone tree for the project will have to get into a list memorized by someone who was awake and near a phone at midnight. Their contribution to society will be to place wake-up calls to a few memorized numbers each morning. Someone who lives near a fabric store and has a car will be in the early phone tree. Their task is to break into the fabric store, with the owner's permission, collect the fabric, thread, and notions for the costumes, and deliver them to the costumers. Each costumer will have rehearsed drafting the pattern, cutting it out, and sewing it for one costume. When they are just rehearsing they can sleep in and start at their normal getting-up time. On dress rehearsal and performance days, they will be in an early phone tree so they can start drafting soon after midnight, and be ready to cut out when the fabric arrives. Similarly, the set builders and painters will rehearse constructing the sets, working out how to build them in no more than 18 hours. They may need someone to break into a hardware store, with the owner's permission, to collect paint and other materials. The lighting people will rehearse hanging the lights and setting up the control boards so that they can do it in 18 hours. If the performance is going to be streamed to the Internet the camera people will also have rehearsed setting up. A successful performance would be to the advantage of a large number of people, so I assume a lot of cooperation to make it happen. Even if the fabric store owner does not like theater, the chef who loves live performances is much more likely to ask them to dinner if they cooperate. Society could operate either on informal barter, or on a "currency" with accounts managed by people who have both very good memories and very good reputations for honesty. [Answer] I won't give a complete answer because the other answers here are sufficient. But I don't think the concept of money has been fully explored. This might work well with Erik's Project Last Hope [answer](https://worldbuilding.stackexchange.com/a/18125/2638). # Money ### History (skip if you don't like historical economics) Most small tribal communities worked with credit systems1 where "gifts" were remembered and repaid with more "gifts". Money was not needed because it wasn't hard to remember that you had given your neighbor a pair of shoes (after he complained about the hole in his). The cycle of gifting was a fundamental part of their societies and worked very well on a small scale. But this made short (village to village) trade hard and long distance trade impossible. So, if trade became desirable, people turned to some form of bartering. And, out of convenience, more efficient bartering techniques were developed along the lines of: 1. A general purpose value item (like hides) becomes an intermediary that avoids the "double coincidence of needs" implicit to bartering. i.e. Everyone trades their stuff for hides and then the hides for other stuff. 2. Large, well known traders start making trades between each other in promises (notes) to avoid having to transport and actually own the item in question. 3. Coinage develops as a more stable and permanent replacement to the intermediary value item. (This usually coincides with a local gov taking over and taxing everything). And then something happens and Fiat currency emerges. But I'm not an economist and my views of fiat currency are rather biased. So rather than making amateur mistakes about it, I will leave it out. ### Function Fundamentally, money is a way of storing value for the purpose of trade between strangers. Specifically, it is: * an abstract form of *universal* value * tied to something mostly permanent but fairly arbitrary (like rare metal) * Accessible and tradeable ### Groundhog Day Money On the local scale, we would likely revert back to a credit-based society (of some form) since credit (positive or negative) would be the only type of value that would last beyond midnight. But this means knowing everyone you interact with or forming "tribes" that remember interactions on different scales. Once you want to move past this kind of society, you need some form of money. Since memory is the only permanent "thing", it must be memory based. And therefore information based. Naively, you could try to get people to remember how much money they all have. But this would require a significant portion of the population to be involved and prone to all sorts of errors. Instead, we should look at current tech: what do we have that stores value as information? **Bitcoin**, of course. Memorize the block-chain, memorize your address, what could go wrong? ### Custom Cryptocurrency So Bitcoin has some problems of course. First the block chain is huge (20gb atm and growing). That's a lot of data to memorize. Even your address is a bit long and random. But this is all because it's meant to be stored and processed by computers. Also because it's meant to be "mined". (Interestingly, you could keep mining bitcoins if the blockchain was memorized). We have different needs for our cryptocurrency. * Small, non-growing "blockchain" * Extremely robust system for distributing the blockchain to be memorized and collecting it again in the morning. * Blame mechanism plus redundancy. (motivate people to not make mistakes and make mistakes survivable) ### Timeline I imagine this to be relevant sometime after local affairs have settled. Some form of community has stabilized in your local area and you are once again interested in "progress" and a feeling of something other than futile repetition. It starts small, maybe goes through a few phases, and then starts spreading around the world as people realize they can start progressing again. That their actions today will actually have some effect on tomorrow. 1 Contrary to popular belief, tribal communities were almost never "barter" economies but something closer to credit economies. See [Debt: The First 5,000 Years](http://rads.stackoverflow.com/amzn/click/1612191290) by David Graeber [Answer] ## It would be a global reenactment of the Zimbardo prison experiment People are not basically good, they act in a way contingent with the society they find themselves in. The notion that most people are basically good is false. Most people appear to have the capacity for casual brutality if the situation allows and expects it, as demonstrated by [Zimbardo](http://en.wikipedia.org/wiki/Stanford_prison_experiment). It would after a while become apparent that the only things with value are experience and memory, the more extreme the better. Experience can take many different forms. I would anticipate that many people would simply take a gun and go hunting. Expect fighting in the streets degenerating into fantastically detailed levels of barbarism as the decades, centuries and competency levels of the participants progress. Those with access to the nuclear launch codes would use them, not once but day after day. Death from above would be frequent, unpredictable and arbitrary. Those with access to enhanced weaponry such as warplanes would treat them as toys, strafing neighbourhoods and stadia. People without access to such advanced toys would band together to storm military bases, fighting each other for access to the biggest bang, the best experience. It would be hell by nightfall, mountains of burning corpses, screaming madmen in bulldozers, aircraft exploding in mid air and raining burning bodies down onto neighbourhoods. Children with the minds of war ravaged old men murdering their parents in their beds and laughing. There would be no escape, you would be trapped forever. No permanent consequences, no right or wrong, kill me today and I'll come right back at you tomorrow. [Answer] I suspect this would happen in the following stages: 1. Confusion 2. Experimentation 3. Lamentation 4. Re-organization 5. Acceptance Similar to Groundhog day, the first several days would be confusing to most people. I think they would figure it out after a while, but not at first. This would gradually lead to the next stage, experimentation. Once it became known exactly what was happening, there would probably be a mixture of reactions. I suspect that the general thought would be that people would experiment to see what was happening. I can imagine a number of things being tried, like someone cutting themselves, breaking stuff, and other very noticeable things to see if it would stay, while some of the more adventurous would try killing someone, perhaps. I think people would generally be pushing the boundaries further and further, until they realized exactly what was happening. Scientists would run experiments, likely looking at the stars and planets to see if they exhibited the same behavior, seeing how far the bubble was. Perhaps they would try other things. Next would come a phase were people would be confused, and wonder why this was happening, and try and stop it from happening. Riots would likely happen in this phase. So would some desperate experiments. Many people would just stop coming in to work. For those things required for normal life to continue, there would likely be some difficulty in getting people there to provide them (Water, power, food, etc). People working stuff that only matters in the long term almost certainly would stop working, as there just wouldn't be any point. Many churches would have higher attendance, especially at first, as people reacting to the drastic change in their lives. Long-term, acceptance would happen. Society would re-structure itself. Likely a new system of time would somehow be created. People would probably come to some kind of an agreement on how to improve life for those around. Those who committed certain types of crimes would be dealt with, so they could not continue to do so. People would try to figure out how to get the most of life. They would likely be concerned about having adventures, seeing and experiencing new things. I suspect that people would take things to the extreme. In fact, I suspect all people would be pushed to the extreme. People would be pushed to be more conservative or liberal in general, further from moderation. Fear of death would not be a real thing. Some people would continue to work just to avoid boredom. [Answer] The first thing that comes to mind for me would be an analogy to [Albert Camus - *The Myth of Sisyphus*](https://en.wikipedia.org/wiki/The_Myth_of_Sisyphus). **One would have a choice as to whether or not to accept the fact that today will be the same as tomorrow.** In the movie, reality was deterministic for the first few awakenings, then Murray's personal growth and new choices changed reality into a less deterministic one. [Answer] I think there would be some big changes, but not the ones most people think. As others have mentioned, this is a post scarcity society. No global warming, no resource limitations. Most people have enough 'money' to buy or do whatever goods they want. But there would be no sellers. So they go to university to learn something, or to a posh restaurant. But there are no staff, everyone is taking the day off because they tried to go skydiving (which was closed, incidentally). However, a new economy would develop, based around the existing services and luxury goods industries. Most other industries would be discontinued. Existing money would have to be replaced. Each person would be required to memorise the net wealth of 3 individuals at the end of the day. A basic algorithm would ensure 3 people memorise each person's wealth (with jail or financial penalties for lying). So while people are not forced to work, plenty of people would (not every day, but when they want more money). Education would become a huge industry. However, it would be a fundamentally unequal society, based on the location you are when things reset. In remote and rural areas, almost nothing would be available, regardless of price. [Answer] > > What of government? What laws will be put in place, if any? Drugs have addictive effects beyond the physical, and there will be great temptation to use. Will the penalties become worse? How can they be enforced? Social programs? Military intervention and distribution programs? What about organizations? The Humane Society, Red Cross, Shriners, Knights of Columbus? How do they remain relevant? Do they? I imagine they will try... > > > First: How do you keep records? In a scenario where everything except for human brains resets each day, how do you write down new laws or contracts for others to study? You might think that you could have people simply remember them, and recite each day, but over the long term that's not going to be viable. The record-keepers will quit eventually. Second: You can't build anything new or permanent. People would have to re-create the infrastructure every single day, and that's not going to happen. Third: there's no point in doing any job. There's enough food lying around to last the day, and you don't need anything new if it'll just be recreated. So losing access to record keeping is going to destroy large-scale governance. Additionally, there's really no economy - why should you care about cash, or gold, if it goes away the next day? Because of these two factors, the only things valuable are: 1. New experiences/education. 2. Protection from hostile actors. So worldwide, society will fragment into two rough groups - conformants and hostile actors. These will organize on a local basis into government analogs, but they will be much more fluid than anything we have today, and smaller. I suspect the largest groups will number in the thousands. **Conformant Groups** will be people who, roughly, want to live their lives as close to normal as possible. They'll group up for protection, traveling a few hours each day to static locations where they can set up a defensive perimeter, and trade knowledge/education/ideas/sex. **Hostile Actors** will be individuals or groups who want to take advantage of others without fair trade. They'll be looking for drugs or sex, since almost everything else is worthless long term. Individuals will probably try to infiltrate conformant groups, although this will be tough since they'd rapidly be found out. Groups would be offensive, looking to capture/assault conformant groups for their use. This will be a fluid situation - a safe spot one day means that a group of hostile actors might try to get their first today. However, I suspect that long-term conformants will massively outnumber hostile actors, because there's simply not much point in going for the rape and pillage thing when there's a reset at the end of the day. So most of the world will be "safe", with islands of hostiles that can't be dug out easily. > > We're also very US/Eurocentric. What about the rest of the world? How will China, North Korea, African nations respond to all this? > > > I suspect eventually almost all of the world will follow the above pattern. You can't keep big governments together, and eventually everyone will fall into localized groups that promote their interests. One thing I do think about most of the rest of the world is that in rural areas, you'd likely see local cults develop around charismatic figures. Without access to first world transportation, these cults would be able to form into hostile actor groups and control/gather all people in their area, basically having permanent slaves. Eventually they'd run into conformants that can defend themselves, though, at which point their expansion would stop. I also wonder if maybe the US/Russia would identify these and eliminate them with the "stop doing bad shit or be nuked" rule, where they have "known" rural cult areas, and watch them with satellites. And if they see the bad behavior, they just launch a nuke, because the long-term negative effects will go away eventually and no one will really be killed. **Conclusion:** This rambled on a fair bit. The main point is it won't be possible to keep large scale governance, so people will organize over time into smaller groups that let them stay protected while doing what they want. Or they'll go for the rape and pillage deal. ]
[Question] [ Yesterday my 7-year-old daughter asked me: > > Why can't I do magic for real? > > > I answered: because of the law of conservation of energy! And I briefly explained this law. Thus she grumbled, "a single law stole so much from us!" This made me wonder about an alternate universe where magic is allowed by physics. What's the minimum set of changes that our local laws of physics would require? **edit:** By "magic", my daughter means any way to obtain a result without **any** effort. For example, she would like to cook an egg by magic, or clean up the room by magic, or transform a stone into a car by magic, and so on. This is why the conservation of energy looked like the most obvious answer: if you find a way to violate that principle in a controlled manner, you can create energy out of nothing and destroy it in a closed system. Then it's just a matter of imagination, and you can create techniques and tools to do anything without any effort (except imagination, but imagination is not a form of physical energy). [Answer] *Tl/Dr: the smallest change isn't one to the laws of physics. It's a small change to the definition of magic.* This is a favorite topic for me. I could talk for hours about it. Not kidding. Find me in chat if you want. There's more magic in the world than we often think! Let's start off slow, with the straight forward physics part of the question. > > > > > > Why I cannot do magic for real? > > > > > > > > > I answered: because of law of conservation of energy! And I briefly > explained this law. > > > Thus she grumbled "a single law stole us so much!" > > > Let's take this one apart. Few people know this, but conservation of energy is actually dug far deeper into the fundamentals of science than it appears. Emmy Noether, in 1915, proved what is now called [Noether's Theorem](https://en.wikipedia.org/wiki/Noether's_theorem). This theorem is so profound that not only is it considered the single greatest addition to mathematical physics by a woman, but may consider it to be the greatest addition to mathematical physics period. Her theorem focused on Lagrangian mechanics, which are systems that are path invariant. For example, it doesn't matter if I roll a rock up a hill, or if I simply lift it up and put it there: the potential energy in the rock is identical in each case. Virtually *all* of modern physics is developed under this assumption. She proved that, if there is a symmetry in the system, there *must* be a corresponding conserved value, because that conservation law will fall right out of the equations. Thus: * If you have time invariance (the laws of physics do not change over time), you **must** have a conservation of energy law. * If you have a translational invariance (the laws of physics are the same everywhere), you **must** have a conservation of momentum law. * If you have a rotational invariance (the laws of physics are the same no matter which way you face), you **must** have a conservation of angular momentum law. So, by this rule, not only would you have to remove the conservation of energy, but you would have to remove the time invariance of the laws of physics. To have "magic" violate the conservation of energy, we need the rules of physics to change every time we cast a spell. *Woof!* Or do we? Noether's theorem works for Lagrangian systems. It doesn't work for other systems, such as those where the path you take matters. What if the path we take does matter? What if the road less traveled *really does* make all the difference? Suddenly we find ourselves in a different environment, where we didn't even need to change the laws of physics to permit magic, just our preconceptions. The challenge with "magic" is that much of what we read in fantasy is so, well, *fantastical* that we develop a definition of magic that is roughly translated as: "magic is the ability to do things you can't do in real life." This is my least favorite definition, and I love encouraging people to shift to another one. This one is a dead end. It always leads to thoughts that start out with "If only I could... but I can't." I prefer the definitions which push at the possible. In this technological world, it's impossible to provide an answer to this question without quoting Arthur C. Clarke's "Any sufficiently advanced technology is indistinguishable from magic." It's such an over-used trope that we often wave our hand and say "yadda yadda, we've heard this before." However, I'd like to draw attention to one little word in that sentence: "indistinguishable." Okay, fine, it's a big word. Six syllables. His definition of magic doesn't include anything about what the magician is doing. It's about what the audience observes. He points out that, while we often like to separate things into nice easy piles using the [law of the excluded middle](https://en.wikipedia.org/wiki/Law_of_excluded_middle), such as "magic" and "not magic," it turns out that for some things, it is *frustratingly* hard to categorize things this way. You really end up needing a third category: "magic," "not magic," and "hmm... maybe magic." I find this third category to be the key to a belief in magic. Let's take the case of [Penn and Teller](http://pennandteller.com/). You've almost certainly heard their names, as two of the most respected illusionists in the magic industry. They've been at it for 45 years, and have seen it all. In fact, they've seen too much. For a few seasons, they hosted a show "Penn and Teller: Fool Us," with the basic premise of inviting lesser known magicians up onto their stage to do magic for them. The goal is for the magician to "fool" Penn and Teller so that they can't tell how it was done. What's fascinating about this is the monologue they give to the audience before the show (and by "they" I mean Penn, of course). He explains that, after 45 years of magic, they've seen it all. They know how all the tricks work. And somewhere, along the way, the magic went away for them, and all that was left was the tricks. So while, obviously, the goal of such a show is to make money, like any show, the private goal for them is to come across just *one* act which fools them so thoroughly that they, for a moment, get to feel the same mirthful feeling of wonder, bubbling up from their gut, that they got from seeing magic when they were five years old. (And, every now and then, [they actually got their wish](https://www.youtube.com/watch?v=CRpz0zuAGVs). *Warning for you and your 7 year old, video does contain curse words, but watching Penn's face just might be worth it*). As you start exploring these things which are indistinguishable from magic, you realize that they show up all over in the our culture. There's something magical about watching the sun rise. It doesn't seem to quite matter that I know it's caused by a $(7.2921150 \pm 0.0000001) ×10^{−5} \text{(rad/s)}$ rotation of the earth with respect to the inertial frame, and [Rayleigh](https://en.wikipedia.org/wiki/Rayleigh_scattering) and [Mie](https://en.wikipedia.org/wiki/Mie_scattering) scattering of photons off of the atmosphere. There's *something* there which isn't quite captured in the scientific jargon, and is different every day, and yet the same. We see it in live music. We see it in the poet's fascination with love. I have a young daughter myself. I was there when she was born. I know the biochemistry. I can explain exactly what happens for the first three divisions of the egg after conception (which is the first point where the male DNA is fully expressed. Some scientists consider *that* to be the moment where it becomes another human being). I can explain exactly which hormones the baby had to emit into my wife's bloodstream to convince her Uterus to let it stick around just a little while longer. I know of that, between stage 28 and 31 of the embryo's eye, it begins a "testing pattern" of sorts, a pattern we literally only see once in our life and never see again, which is responsible for helping sort out the mapping from the optic nerve to the visual cortex. I can tell you that she, as newborn, had roughly 26 billion cells, expelled from my wife's body under the influence of some of the most powerful drugs our body has ever developed. And you know what? Despite all of that, I'll be damned if I'm to distinguish those 26 billion cells from anything but a miracle. Damned I say. When I watch her stare in marvel at a [Gestalt pattern](https://upload.wikimedia.org/wikipedia/commons/6/63/Reification.jpg), trying to make sense of what she sees, she's not the only one staring in marvel. I watch her eye darting back and forth, and truly have to question "How could this *ever* be treated as nothing more than a squishy bag of cells?" To me, that's the state where magic occurs. Not when you *know* something is impossible, but when you're not entirely sure. Is the old lady with a Tarot deck simply reading my biophysical tells and telling me what I want to hear in exchange for my money, or does she really know something that I don't? --- > > By "magic" my daughter means any way to obtain a result without any effort. > For example, she would like to cook an egg by magic, or clean up the room by magic, or transform a stone into a car by magic and so on. > > > "Without any effort" is a hard definition of magic. Many fantasy novels have spells which take a great deal of effort. At the very least, you have to say some words or wave a wand. What does "effort" mean? It [takes](http://www.scientificamerican.com/article/thinking-hard-calories/) 10.8 calories per hour to run the human brain, and its hard to say if it burns any more doing heavy thinking. A child at play burns about 400 calories per hour. Ask your daughter which takes more effort: playing on the playground, or math homework. Some things take very little effort at all, because what we wanted was almost already there. We just had to coax it into being. If there is already an egg, suspended on a string over a pot of boiling water, cooking an egg with a magic wand could take as little effort as waving the wand in a manner which breaks the string, and lets the egg settle into the boiling water. In fact, if she can do this messily enough, there's a good chance a parent will rescue her (and the kitchen), and finish cooking the egg for her! How's that for little effort? The key to such a sense of magic is sensitivity. Sensitivity to everything in the environment around you. If you'll notice, magicians in the fairy tale books often wont cast a spell unless the time is right for it. I certainly wont be casting my egg-cooking spell unless I notice someone has already decided to suspend the egg over a pot. I'm not going to do a "pull a quarter out from behind your ear" trick unless I'm confident I can palm the quarter there in the first place. Is it magic? Well, I know the trick, so it's just an illusion to me. However, if I do that to my daughter, and she smiles, that's magical to me! So if I can do an illusion that she thinks is magic, and she can distort her face into a smile, and I think its magic, how badly do we want to draw the lines between the events. **Can we just say "Me producing a quarter from her ear causing her to smile" is actually magic?** Am I really *forced* to put a line between those two parts, and make the magic go away? Where does this all lead? Anywhere you want, really, but I do think one of the most amazing places it leads is into exploring what your body can *actually* do. It is so much more capable than we think, and its full of magic. For example, you eat food. You can look around with your eyes, process the scene, identify something which contains calories and nutrition, break it up mechanically with your mouth and chemically with your stomach, and extract value with your intestines. Everything I just mentioned is in the upper torso. As far your legs are concerned, the fact that they get calories and nutrients in the blood stream is, well, magical. Now let's put your legs in a position to be magical. Jump (from a reasonably high height) and land on the ground. One of the first real warnings you get that you hit the ground is a strain in the patellar tendon from being stretched by the lower leg reacting to the ground while the upper leg and rest of body continue downward. Sensory nerve signals travel at 80-120mph. That's about a 80ms round trip from the leg, to the brain, and back, ignoring processing time. If you had to take *effort* to resolve this situation, you wouldn't have time to innervate your leg muscles fast enough to catch yourself. In reality, with processing time, the numbers look closer to 200 or 300ms. Instead, the signal takes two paths. One path notifies your brain that something's amiss. The other path goes up your leg, to a ganglia at the bottom of your spinal column. There' it has a monosynaptic link to quadriceps. A monosynaptic link is one where a sensory neuron connects directly to a motor neuron, without any interneurons between to do processing. It's the single fastest link possible in the human nervous system. That link innervates your quadriceps as fast as they possibly can, to catch you. In fact, they are contracting before you are even aware that you hit the ground: This is known as the [Patellar Reflex](https://en.wikipedia.org/wiki/Patellar_reflex), and its what the doctor tests when they bump your knee and your leg twitches: > > This reflex is a reflex of proprioception which helps maintain posture and balance, allowing to keep one's balance **with little effort** or conscious thought. > > > Without even thinking about it, your legs catch you, three to four times faster than you could catch yourself if you expended "effort." Without them "thinking" about it, they are provided with the nutrients and energy needed to make that trick possible. By the way, while the patellar reflex is the best known of these, many other tendons exhibit a similar reflex, such as the ankle and elbow. Every one of these does something you couldn't do with effort if you tried. Do I really have to say that's not "magic?" [Answer] The problem is mostly one of semantics. You can't "do magic for real", because all of the things that you can do for real you consider to not be magic. You can have a conversation with a person on the other side of the world, and if you drop enough money on it you can have dinner with them tomorrow. But those things don't count as "magic", despite being utterly impossible 100 years ago, because we can now do them for real. Magic needn't always violate conservation of energy. So far as the laws of physics are concerned, the energy required to read someone's mind (either for general-purpose telepathy or to work out what card they picked) could be very small indeed, well below what the human metabolism can provide. Producing a rabbit "from nowhere" would require an immense amount of energy, but producing a rabbit from *somewhere* is a problem of transportation. So in some sense, the minimum change to the currently-understood laws of physics to allow magic is *absolutely any change*, or even *none at all*. Whenever we discover something new, or even just invent a new way of arranging ideas we already knew, then something that formerly was as far as we knew "magic" is now "for real". And that's without even getting into the beliefs of those who genuinely think that current scientific theories are fundamentally overlooking certain phenomena that reasonably can be called "magic", or that the definition of "magic" should include things that current science acknowledges do happen for real. Most magic, though, is "things we wish were possible but believe are not". If by "do magic" you mean the power to do *anything you wish*, as opposed to just doing a few new things, then nothing we'd recognise as similar to the laws of physics will allow that. The reason is that laws of physics describe what *must* happen in a given situation (or at any rate what will *very probably* happen), and one can always wish that what actually happens is different from what the laws predict will happen. [Answer] I'd say it entirely depends on what magic means to you. **Something that follows no discernible rules** Example: magic granted by supernatural/godly/other-dimensional beings, who might grant a wish or not, in the way you imagined or not. The beings can't be studied or reasoned with; they act entirely randomly. Well, if you can't study magic in a scientific way because it is unpredictable due to its inherent features, then you might just as well throw all science out of the window. If you know what something behaves like without magic, but cannot tell when magic is influencing it and in which way it influences it, then you might just as well know nothing about it. If magic only happens very rarely, you can stick to all your normal science and just chalk up any deviations to magic. Why can't you do magic for real in this case? Well, you've got no way of knowing where such godly/otherwoldly beings are, and how to convince them to do magic for you. You might just need to try harder and have more luck than winning the lottery 10 times in a row. **Reproduceable magic whose effects violate current laws of physics** If you can measure magic and its influence scientifically, and the results go against what your non-magic science predicts -- well then it's pretty much time to add something to your non-magic science. * some kind of elementary force joining your 4 forces (electricity, gravity, weak and strong nuclear force). Once you learn the rules of this new force, add it into current theory, everything becomes predictable again because you won't be violating the new laws anymore * set up a new theory for an n-dimensional space instead of our regular 3D+time space. Properties of those invisible dimensions might result in things that might seem like magic to us, but are entirely explainable. Example: imagine not knowing that the earth is round. You think the earth is a flat plane, and you want to discover where this plane ends. You walk in a straight line for ages, sail the seas in a straight line, walk some more -- just to realize that by some inexplicable magic you eventually arrived again where you started out. You must have encountered a fearful daemon to have your way deviated back to your beginning, indeed! * It might even require trying to quantify something like 'soul', 'will', 'determination', etc. Whichever it is -- you will need to add something to current physics to get to a once again comprehensive physical world model. (this one interpretation of the famous Arthur C.Clarke quote of "Sufficiently advanced technology might seem like magic") Why you can't do magic for real in this case? Well, do you know what it is you are supposed to be doing, i.e. what the magic looks like? And, would it still be magic if it's just a strange part of science we haven't discovered yet? **New applications for current physical laws** The primary interpretation of Arthur C.Clarke's quote "Sufficiently advanced technology is magic". Imagine Thomas Edison, who invented the light bulb. Yes, he knew what electricity was, what a phone was, and I'm pretty sure he also knew about wireless transmission. Would he think the abilities of an old-fashioned mobile phone magical? Perhaps. A smartphone? I sure bet he would. And that's only what we've done with science in the last 150 years. All in all, you must never forget -- science is not set in stone. First comes the theory to explain observations (all apples I have ever seen fall downward). Eventually, if the theory has been sufficiently verified (not only I have seen apples fall downward, but my family too and my neighbors and my professors and people on the other side of the globe), it becomes a law (all apples fall down and not up). And only then can it be used to predict things that haven't happened yet (when I let go of the apple in my hand, it will fall downward). However, the first time an apple floats upward, it requires a really hard look at current laws and the circumstances under which the apple fell upwards (I was hanging upside-down from a tree -- in my perspective, the apple went from my toes to my head instead of the other way round). So, there is plenty of ways of finding 'magic' even within our current physical laws :). And of course, you can do 'magic' by studying science and trying to come up with new, revolutionary ways of using it! [Answer] You might point out to her that she already does magic. Tell her to turn on a light. Can she explain how she did that? Have her turn on the TV, and explain to you how she can bring up images of people (even dead people, if she likes reruns) who talk to her. Get a copy of Dragon speech recognition software and install it on your computer, then ask her how something can respond to her voice. At seven, she's probably too young to have experience firing a gun [![enter image description here](https://i.stack.imgur.com/amONJ.jpg)](https://i.stack.imgur.com/amONJ.jpg) but she's surely familiar with the idea. Ask her how pulling a trigger is different from throwing a lightning bolt. The answer, of course, is that she's used to doing everyday things, and doesn't think about them, but the things she can't do are magic. It's like with artificial intelligence: "If we know how to make a computer do it, it's not AI." As Paul Simon put it, "These are the days of miracle and wonder". Magic, in general, has effects without physical causes. Depending on what stories you read, it is either accomplished by calling on supernatural beings or simply by the exercise of will, just as we move our fingers simply by wanting to. Wishing makes it so. Trying to tell a seven-year-old that this just doesn't seem to work outside of stories is a pretty hard sell - children fundamentally believe in magic. As for your literal question, the answer is that no set of changes in physics will allow magic to work. Conservation laws simply don't count, since you can simply assert that any unaccounted-for energy required is provided by magical transmutation, including fusion. (Because it's magical, there are no radiation side effects.) The big problem with making magic scientifically usable is that it destroys science. That is, no experiment can be trusted: its outcome may be altered by magical means. With no experiments which can be trusted, the cornerstone of scientific endeavor, Poppert's falsifiability, becomes impossible. [Answer] # None Magic is possible, as soon as we find a way to tab into a source of unlimited energy. The point is that just because we didn't discover that source yet, does not mean it does not exist. But, after you found it, this will happen: > > Any sufficiently analyzed magic is indistinguishable from science. > > > ([Agatha Heterodyne](http://www.girlgeniusonline.com/comic.php?date=20081205)) Of course, to get the "make a wish `->` see it happen" kind of magic to work, you "just" have to make cause and effect stop working at the place you are at and wait for the random chaos to be in the shape you want it to. [Answer] Everything, or nothing. You've noted the law of conservation of energy. Well, this isn't the only reason. Suppose you want to conjure up matter as your magic trick. The law of conservation of mass applies, obviously, unless you're taking it from somewhere else, which would violate the universal speed limit. But there's more to it. Something has to happen to the air that used to be in the space your conjured object now occupies. Conservation of mass applies, after all. This has to happen before the new object can occupy this space. Why would it? You'll need to make alterations to fluid dynamics. The short of it is, if you're going to change physics, you have to change it all because it's all so related. Maybe I've decided I want kinetic energy to be $K = mv$ instead of $K = \frac{1}{2}mv^2$. Well, $W = \int F \cdot dx = m \int a \cdot dx$. Now we're talking about the basic $F = ma$ formula that physics is built on. If you're gonna change that, the whole universe is now entirely different. But on the other hand, maybe there's a way you can make all this stuff work without actually changing any laws of physics. Though if so, stop talking about it on worldbuilding.se and go patent the ever-loving crap out of it. [Answer] > > This made me wonder of an alternative universe where magic is allowed > by physics. What's the minimum set of changes that our local physics > laws would require? > > > The laws of physics require that if magic exists then *they* don't. The minimum change to physics that would allow *real* magic is the nonexistence of physics. All science depends on the expectation that the universe operates by regular cause and effect. If the laws of physics are no longer laws, just guidelines, then the ground is cut from under the feet of the whole idea of physics. That is not to say that our understanding of the laws is necessarily complete. Perhaps someone could cause things to happen by willing them in some manner that is functionally equivalent to magic but actually is within the wider laws of physics, if we but knew them. That is not to say that the physical constants such as the speed of light, or rules like the conservation of mass-energy, that we think of as applying everywhere necessarily do. That is not to say that what we think of as "the universe" actually is all of the universe. That is not to say that there cannot be a God who created the physical universe and its laws, or intervenes therein. That said, if anyone can think of some nifty physics workarounds to explain apparently magical doings, don't be shy, because it would really help with the story I'm stuck on. [Answer] Well, technically speaking, there's nothing wrong with our world. Magic and miracles are just manifestations of power which humans aren't able to do. But in itself, magic isn't opposed to science. It's just too difficult for us humans (well, some kinds of magic are illogical, but that's not the point here). **The changes required are *for us to be more powerful***. As for how much more, it all depends on what you want to do. For exemple, invisibility would be possible if we naturally did [these kinds of things](https://en.wikipedia.org/wiki/Invisibility) which already aren't fiction anymore. (tell me if you have a better link) So it is more about us than about the world we live in. [Answer] Since most magic *as described* violates various conservation laws, or the laws of thermodynamics, it is by definition impossible. However, since we want to go from *impossible* to at least *improbable* the best thing to do is look at quantum mechanics and see how to change probability. We "know" that Space-Time is a seething flux of energies and matter, with particle-antiparticle virtual pairs appearing and disappearing all the time at the Planck scale(no one has actually "seen" this, but we can infer this from effects in the visible universe, and it allows us to make mathematical calculations to describe what is happening). While we really don't understand this very well (the supposed energy in a volume the size of a coffee cup could theoretically boil the oceans of Earth, yet there are no visible effects due to gravitational lensing on the scale of the Universe), gaining the ability to tap into this source of energy, or dump energy back into this as some sort of heat sink would allow you to do serious magical activity without violating thermodynamic laws (you are simply transferring energy and matter to and from a vastly larger pool, and using different timescales to manifest the effects). Quantum mechanics also postulates that things and effects are due to the "collapse" of wave functions due to the activities of an observer. The Schrödinger's cat thought experiment is a good example of how this effect is supposed to work [![Schrödinger's cat](https://i.stack.imgur.com/xfrTm.png)](https://i.stack.imgur.com/xfrTm.png) Getting a rabbit out of a hat then becomes a matter of arranging for an observer to collapse a wave function where a rabbit is *already in the hat*. Since the probability of a particular rabbit being in a particular hat at a particular time is a known function (or at least calculable in principle), then a sufficiently trained observer should theoretically be able to "find" the probability of a rabbit being in the hat, reach in and grab the rabbit out of the infinite possibilities of rabbits/not rabbits/ alligators/ other things being or not being in the hat. Obviously this will require a lot of care and attention..... Of course the less "probable" the effect you want (walking through a wall, for example) the more difficult it will be to do. This degree of difficulty, coupled with the amount of computational power and focus needed to "find" and "observe" the magical effect desired explains why magic traditionally has been in the realm of the gods and a very select body of wizards. (Read Lord of the Rings or Le Mort d'Arthur very carefully to see just how little actual "magic" Gandalf or Merlyn do. Remember in LOTR, Gandalf is actually the equivalent of an *angelic being* to keep it in context). [![Gandalf](https://i.stack.imgur.com/JB3Hr.jpg)](https://i.stack.imgur.com/JB3Hr.jpg) I find blowing smoke rings far easier and more relaxing.... [Answer] The smallest change to the expression of the laws of physics that allows magic would be something along the lines of "The laws of physics are <real laws of physics>, except that, when I say 'abracadabra' whatever I say next will happen." [Answer] > > imagination is not a form of physical energy > > > I believe the answer is predicated on dispelling this false assumption. Imagination is a function of the human brain, which uses electrical and chemical signals to produce conscious thought as well as control involuntary processes. > > It is well established that the brain uses more energy than any other human organ, accounting for up to 20 percent of the body's total haul. <http://www.scientificamerican.com/article/why-does-the-brain-need-s/> > > > So, while it may not be a 1:1 correlation (thinking hard has been found to cause only a minor increase in calories burned as per <http://www.scientificamerican.com/article/thinking-hard-calories/> which alludes to the fact that perhaps the most complicated tasks our brains do have nothing to do with conscience thought at all), imagination DOES indeed require energy. There is nothing that says that physics and magic have to be mutually exclusive, and, in basically all popular fantasy novels and games, magic is something that doesn't just happen and also seems to follow some predefined laws. Fantasy games generally use the concept of some arbitrary energy unit that is consumed when a spell is cast (otherwise the player would simply cast the most devastating spell over and over until the game was over). In LOTR, why didn't Gandalf just transform the opposing army into firewood or rutabagas using a word? In my opinion it would have made a VERY uninteresting book. It seems that even imaginary universes can't exist without laws, because without laws no one would care about them and they would cease to be (being imaginary and all). Considering the possibility of alternate universes with different physical laws where a being COULD simply make something happen with no expediture of energy, that universe probably ceased to exist because one of these beings thought it should cease to exist (bad case of the "Mondays"). In a universe like ours, that scenario is prevented by the fact that too much energy would be required to convert all the remaining matter in the universe into energy. If we impart some rules on magic, suddenly it doesn't look so daunting. What is lacking is OUR human ability. We don't need to change laws. We need to evolve. If we could evolve a way to generate an ultra-powerful magnetic field (why not? eels can generate electricity) or lasers (advanced bioluminescense), then why couldn't we channel that ability to convert photons into matter (<http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_16-5-2014-15-32-44>)? With enough ability, why couldn't we arrange that matter in any way we want? After all, "stuff" is just a bunch of atoms arranged in particular ways. With enough metabolism to back the activity, why couldn't we arrange freely available sunlight into a pizza? That sounds a lot like magic AND science to me. Now, since it wouldn't be a lossless conversion, you couldn't infinitely make pizzas from sunlight and energy gained by eating the pizzas, so you would need an external energy input, but I am pretty sure that the wizards in games and books have external energy sources too (potions, food). It all works out. And that being said, go back to the electric eel for a second. I believe it meets the definition of magic (produces electricity capable of killing a human via cell vibrations simply by "thinking" about it). We've explained how it works, making it science, but as soon as we explain exactly how ANY magic works, THAT will become science too. Being a magician might be just like being a computer programmer... a skill you learn using your mind and body. The programmer arranges code and types it with his fingers. The magician architects matter structures and arranges them with his hand, or wand, or staff, or whatever. So, tell your daughter the truth... magic is absolutely possible AND it is real, but has some rules (because without these rules, it wouldn't have the opportunity to exist). The magic we see in movies isn't "real" magic because movies and books have a REALLY bad habit of NOT considering rules (ever watch the cops in most cop shows? They'd all be in jail...). Then head off to the aquarium or science museum and see some in action. Eels turn food into energy into motion back into energy. We turn food and light into electrical and chemical impulses which we interpret as thought, which we then turn into a painting, converting that thought into a physical thing with brush that looks a lot like that instance of light we originally saw reflecting off the object we painted. We might not be able to turn a rock into a new bicycle (well, we can, but it is a long process involving first extracting the iron and so on), but neither could Gandalf turn Orcs to rutabagas. Therein lies another lesson for a child... even the most powerful and amazing forces follow rules. [Answer] Providing that something is "magic" depending on personal background (in example a country-side may look "magic"), if few humans were able to manipulate mind and cause allucinations to someone else, than the person subject to allucinations may as well live a whole life believing to see real magic, so in a certain sense he will "have magic" without even the need to change a physical law. However, you are asking specifically for a change of a physical law. The fact that we are in practice out of control on nature is basically the "lack of magic". To have magic we need to have control on nature, the simplest thing came to my mind is Entropy, **Entropy** can only increase: * If we have a box with air particles randomly travelling inside the box in practice it never happens that the particles will be ALL on the same side of the box. If people can be in someway able to control phenomenas that actually look random, we can start getting amazing things! (so give the ability to reduce Entropy.. in some way) In example, air particles could randomly hit a body only from one side, effectively helping making the body levitate in thin air. Of course we are still respecting energy conservation (after a particle hit the body and the body moves, the particle lose energy and get cooler). We are currently 4 dimensional beings (at least) because we move forward in time and we have a volume, being able to choose a immediate near future where to live (in example the future where all air particles hit a body from below at same time) may make us 4.1 dimensional beings and could explain the ability to influence our surroundings. In such world the magic would still be limited by other natural laws, and understanding we have of other natural laws gives us more control (we know better immediate futures where we can walk). A strong mage may know that items have thermal energy, so he can levitate objects that are in void (with the constraint that those objects will become cooler). Freezing someone would be indeed a possible magic in such world. Of course there will not be any counter magic, every mage simply wins (from his personal point of view), because every mage go in his immediate future. I'm still not sure how that will affect a civilization. There will be a explosion of divergin futures (right now I don't believe our universe would be much "divergin") [Answer] I think you need to define 'magic' first. What would seem magical to a child of 7 might not seem so to a physics professor or an engineer. If you'd told an educated 17th-century European that he could see someone on the other side of the world this morning, talk to him, hear him, as if he were in the same room - that might indeed seem magical to him. Then to clinch it, tell him he and this other man could have breakfast together in the same room, at the same table, passing food back and forth to each other. That would seem beyond magical. But to your daughter? Ho hum. So what would she call magical? Probably the ability to be in more than one place at the same time would be the most impressive. Then the ability to know the future in precise detail. Those two are about as magical as you can get. For the first, you'd need to be able to violate the conservation of matter and energy. For the second, you'd also have to violate the laws of entropy. When you violate these, you've trampled over the law of cause and effect, and then nothing at all remains of physics. Which goes to show that if you abandon the smallest part of physics, you lose all of it. I am not saying that we know or understand all of physics, but we have reached a stage where we can say that what we have may be incomplete, but it's an integrated, unified structure with no spare parts to jettison. So you and your daughter have to accept - it's physics or magic, but not both, and you'd better both hope it's physics. [Answer] Let's take the most well-known alternative universe which involves magic: Harry Potter. What do people in Harry Potter do that we, as Muggles, can't do in the real world? * We can't channel energy as spells through wands from our bodies * We can't make potions as described in the universe(but some of them we could, if science advances enough) * We can't teleport(Apparate) or use Floo Networks or Portkeys. * We can't make other objects move telekinetically or change their physical characteristics directly(we can through irradiation, but let's leave that out). * We can't make things out of nothing * We don't have things that have different sizes from the inside and outside. * We can't predict the future * We can't talk to ghosts * We can't transform into animals * We can't animate otherwise lifeless objects(such as statues or Inferi). * We don't have animals that breathe fire or anything similar Some of these things can be changed by manipulating Nature, some can't. Let's analyse them one by one. **We can't channel energy as spells through wands from our bodies** This can simply be achieved by violating the law of conservation of energy, as you suggest. Then we'll be able to yield infinite energy without any being taken away from the body. We could also make it any form we wanted, leading to different kind of spells(not all, though). **We can't make potions as described in the universe(but some of them we could, if science advances enough)** Well, in our world, medicines are a kind of potion. In that sense, we can make potions, but not most of them, like the Polyjuice Potion. I'm doubtful if some could be made at all, like the potion which makes pictures move, 'cause that's not how pictures work. **We can't teleport(Apparate) or use Floo Networks or Portkeys.** This'll also require the violation of the law of conservation of mass-energy, or the attempted teleportation of a single person will destroy all life on earth, as the only way to really "teleport" is to convert oneself purely to energy and back into being at the destination. We can use some types of Floo networks(faxes and the Internet come to mind), but they're no match for really being able to send people though. Wormholes, if made possible, would also be a type of apparition, as the feeling described in the books could be similar to the one of travelling through a wormhole. **We can't make other objects move telekinetically or change their physical characteristics directly** Here I'm talking about the chess set and Transfiguration. Transfiguration will also require conversion to pure energy and back, or somehow being able to split any element to hydrogen and recombine to needed element. I'm not sure how you'd breathe life into the 'raised' object though. **We can't make things out of nothing** I'm not really sure how this one works, but your theory of the law of conservation of energy should come here too I suppose. **We don't have things that have different sizes from the inside and outside** We'll have to change the law of conservation of space - effectively allowing fitting a 787 Dreamliner jet inside a courier carton. **We can't predict the future** This'd require time travel. Perhaps someday we'll evolve into 4D or 5D beings or something and then this one will come in, but until then, no future predictions for you(reliable ones, at least). **We can't talk to ghosts** A ghost is just a lone soul, without a body. Can't blame Nature here. The concept of a soul is not natural; life is just the effect of thousands of chemical processes happening in sync inside living things - they stop, the soul's gone. So we could make a crude comparison to a radio that's on as alive and one that's off as lifeless. Basically nothing physics can really do here, it's not involved. **We can't transform into animals** This one's similar to the fourth or fifth one. Undefined behavior on recombination. **We can't animate otherwise lifeless objects** We do have a variant of this one already - robots. But they are 'alive' for a reason similar to the seventh one - a series of processes that make it possible. I'm not really sure, but my best guess here would be 'everything about the way living things work will need to change'. **We don't have animals that breathe fire or anything similar** This is similar to the first - we'll need to break the law of conservation of mass-energy. Any animals alive in the world simply can't absorb energy from their surroundings fast enough to project it out at that rate. And living things are carbon-based, which means breathing fire will burn them up from the inside. So I guess life will have to exist as non-carbon based - iron as a candidate, anyone? So I'll second what some others have said: depends on your definition of magic - but I don't think any single law will be enough - our world is too different and too complicated. [Answer] **Laws of physic are just an old habit** There are already quite inspiring answers here. I just want to point out something not outlined so far. We are used to see the laws of physic as stable and everlasting, they have ever been, they will ever be, they will never change. *We only believe that. We have no evidence.* When where these laws born? Have they already been before the universe was born? Are they a fixed part of our universe and could never have been different from what they are now? That is implausible. A least, we already know that our universe is not mechanic, but has an unforseeable base of events in the smallest known parts of matter, not following the used thoughts of cause->impact. Think of this possibility: As the universe was born in a big bang, there have been no laws of physic. Matter and energy was something completly new, and nothing and no one told them how they should behave. But they happened to *be*. And they interacted with each other and got used to behave in new ways that never have been defined. As time goes by, this used-to-behave become a habit, this habit established over some X\*1.000.000.000 years. These habits are what we see as stable laws with obviously (?) no exception. (Compare this book: *Rupert Sheldrake: Morphic Resonance - The Nature of Formative Causation*) You know, habits have their own power, and it is difficult to diverge from them after getting older than xy years. What about the universe? It is quite old, yeah. You don't need to change the laws of physic. It is enough to persuade the universe to deviate from its habits a bit. Nothing needs to break. It is always possible that something quite improbable happens. The magician knows how to summon the universe to do something really crazy. Little daughters do crazy things, too, not foreseen by adults. [Answer] A magic wand is simply a Star Trek transporter combined with a replicator and miniaturized. Of course, voice activation/recognition is simple for a race this advanced. When not speaking the wand uses telepathy to communicate with the wizard - of course most wizards need to sync their brain waves with the wand, which is why Harry Potter and the rest had so much trouble using it. It took years of practice and schooling. The wand does not violate any sort of physical rules, as it absorbs matter from the air, ground, or whatever is handy and converts it to energy and back again. You probably couldn't re-animate anyone, but even today using CPR we can revive someone who has been dead a few minutes. By replicating nano-bots you could form a swarm of them into any shape and have them move around and do stuff. They could even seem like ghosts, by simply changing their color,arrangement, and density. Using a proper containment field, it could even store energy/matter in a micro blackhole inside the wand. [Answer] > > By "magic" my daughter means any way to obtain a result without any > effort. For example, she would like to cook an egg by magic, or clean > up the room by magic, or transform a stone into a car by magic and so > on. > > > The first two are easy. They've been available for millennia. You tell a servant to do it. Transforming a stone into a car is more difficult. (I suspect the OP added that themselves ;-) A rich person could order a car and get someone to wait round the corner with it. They then tell the child to close their eyes. Hide the stone and the car appears. > > This is why the conservation of energy looked like the most obvious > answer: if you find a way to violate that principle in a controlled > way, you are able to create energy out of nothing and destroy it in a > closed system. > > > Who says it's a closed system? The planet Earth isn't a closed system. We continually get energy from the sun. Maybe the sun outputs mana, we just haven't detected it yet. In the far future who knows what's possible? You simply can't specify a local closed system as a counter-argument to magic. [Answer] As others have said, it partly depends on what one means by 'magic'. Here's my two cents: **Magic is the capacity for people to make things happen in the world immediately through acts of speech *(or gestures, which can be construed as a means of speech ['sign language'])*.** I.e 'wishing makes it so'. This used to be impossible given known physics, but not anymore - or haven't you heard of **Siri**? More generally, our continuing expansion of the things we can do with computers and programming *(e.g 'the Internet of Things')* can - and in my opinion maybe *should* - be construed as laying the infrastructure for a future in which practical magic actually exists. [Answer] Magic is real. The only reason your daughter - or most other people for that matter - can't do it is because some well financed evil wizard and his army of rainbow vampires is draining all the mana from the mabric. Getting only a pixel of the mana that's left takes a lot of meditation, fingerpainting, hugging, a healthy diet, singing and other rituals. Patience and will are both fruit and fuel in this endeavor. It's basically a matter of opening the eye. Also trippin'...' [Answer] The Standard Model of particle physics has different composite theories, such as electrodyamics and chromodynamics (EM and strong nuclear forces, respectively). I recently went to a physics talk where the presenter proposed another composite theory based on combinations of different particles and their interactions. A composite theory could add another "force" depending on how it dictates interactions. A new boson, such as is suggested by the LHC, could provide support for a new, artificial force. In short, a new force, artificial or otherwise, may be your answer. [Answer] Cort Ammon wrote: > > If you have time invariance (the laws of physics do not change over > time), you must have a conservation of energy law. > > > OK, posit then that time invariance gets broken -- the laws of physics *did* change -- the Old Gods woke up, and they're not (for instance) great believers in all that bookkeeping nonsense in Thermodynamics; it cramps their style. And those big, sudden entropy/enthalpy changes look (to the survivors) indistinguishable from magic. [Answer] **Our laws of physics are just as good as any other, or just as bad as any other for magic** (this answer is unfortunately a response to the many other answers here) There is one simple reason we can't do magic, because **if we could do it, it would not be magic**. If we lived in a world without the conservation of energy, we would be just as bored as we are now. What makes magic fun in fiction is that the characters do mundane things like say words, and get special effect. In any world used to that set of rules it would not be fun, it would be boring work. If fact we do not live in a world that conserves energy any more or less than a common magical world. Most magical worlds have power sources, and ours is no different. Our most common power source is the sun. It constantly provides us with new energy external to our system, no different than channeling spirits, or drawing mana is in any magic setting. We can also imagine people living in a world without electromagnetism thinking about how magical we are to be able to move objects at a distance with magnets, and make lightbulbs glow. As for doing something without **any** effort, that is also a logical flaw. **No one in fiction uses zero effort.** There is always a wave of the hand, a magic word or at least a thought. Are voice operated systems magic? We always need a way to explain intent otherwise the events would just be random and not magical at all. What about magic that does things before you ask? Is Google telling you about traffic without you even asking magic? So magic and supernatural can only exist in fiction because that is what the words mean. If we don't have an energy issue any more than any other magic world, and we can give commands to things our world is just as fit as any other for magic. We simply need to push our tech level to achieve the ease of use for whatever your definition of magic is [Answer] # Without overthinking this the answer is derived simply by definitions of the problem Reading answers pretty carefully I haven't seen anyone directly go into the definitions of physics or magic for their responses. And so this answer grabs a dictionary and answers the question objectively. ## Physics is a science first; science is a philosophy. Physics is an accepted philosophy about what effects occur with a given cause. I'll refer to Oxford's definition which lumps the sciences (philosophies) into mechanics, heat, light and other radiation, sound, electricity, magnetism, and the structure of atoms. ### Diving deeper: **Science here refers only to the natural sciences.** While many people including scientists bow down to natural sciences as a surrogate for God and grant it omnipotent power over all things known and knowable, science itself just shrugs and reminds us that it is indeed a box with walls, and some things are very much outside of its box. I.e., (Natural) Science is not just magic with a funny spelling as every science fiction story will tell you. The box of stuff that natural science can work with is exactly defined. Anything you can observe or have observed that doesn't fit inside this definition, can't even be looked at by anyone practicing the natural sciences. It's outside of the box that science drew for itself. This definition, has been elusive, but has some fundamental commonalities. ### WILLIAM T. RICHARDS, PRINCETON UNIVERSITY, NEW JERSEY, 1928 > > “Almost every man of science since the time of Aristotle has tried his hand at defining his profession, and a continuation Of this practice must without the least hope of originality…. ***Science is the systematic description of phenomena.***” > > > > > “**Phenomena**," with its implication of **reproducibility** and of **common experience**, separates the physical sciences alike from the arts, and from some aspects of the psychical. Again, the word "**description**" patently suggests the necessity of a **language for the expression of scientific generalizations**; the language employed is conditioned by the nature and degree of development of each branch of science, **mathematical statement being**, of **the common medium of the physical sciences**. Finally, the qualifying adjective "**systematic**" serves to **distinguish scientific statement from merely casual**, if empirically substantiated, expression of experience. > > > Therefore, when your question asks to change physics, you are asking for a world where *phenomena cannot be systematically described*. That is all that is needed to allow observations which would qualify as magic, or, more literally, "supernatural" which exactly means "situated or placed above natural." A supernatural phenomena is, therefore, a phenomena which defies any of the qualifiers of a natural phenomena. **The philosophy that suggest all known and unknown observations do and forever will obey natural laws** is a dogmatic religion called scientism. It is irrational. It's premises do not vest in reason or fact, are purely axiomatic assumption about unknowns, and are antithetical to scientific progress. But it has a purpose. When we approach a phenomenon with the scientific philosophy, there can be no assumption except that the phenomenon can be "systematically described." It is absolutely imperative to observe that this is an ASSUMPTION, and without that assumption, you simply cannot put your observed phenomenon into the natural science box. If you even consider that your observed phenomenon was, for example, the product of a druidic curse; then none of your scientific tools will do you any good. Your problems will manifest everywhere at once, but specifically; you will NEVER be able to reproduce the curse, and therefore you will never be able to use the word "systematically" to describe it. The phenomenon certainly can still be studied, but never with that supernatural assumption. Your assumption MUST be that the phenomenon, no matter how bizarre, is a reproducible, common experience, that can be described mathematically. ## The following assumption is untrue about natural science: **if we could do it, it would not be magic** Because of the box William T. Richard and many others have drawn around science, "reproducible" is not the one and only part of the definition. But now that we have a good definition of science, phenomena, and physics, let us explore breaking it by going into definitions of supernatural phenomena, which are all currently allowed by physics. ## Miracles A miracle is very simply any phenomena that can not be reproduced. It is a one-off event that nature can't ever do again under any circumstances. Physics allows miracles as it currently exists. Miracles are outside of the box of things physics can even look at, because they CAN NOT be reproduced; therefore they CAN NOT be studied. An example of such a phenomenon is the apparition at Fatima, Portugal on October 13, 1917. This event was witnessed by thousands of people, including children, and was extensively documented through photographs, eyewitness accounts, and official church investigations. The apparition at Fatima is a phenomenon (check), with common experience (check), however it cannot be reproduced, and it can not be systematically described. Therefore, neither physics nor science in general can *deny* the apparition at Fatima, the phenomenon was also not provable as a natural event. Thus, physics currently does allow apparitions such as those documented around the world by photographs and accounts. Physics will never (and can never) *describe* this miracle, or any other, because miracles are not in the box. Other miracles that work fine with modern physics include walking on water, parting seas, raising dead, multiplying food, healing blindness or cancer or heart disease, and crumbling city walls with a song. Physics will certainly say that it can't happen again, but it can never declare that a well documented and commonly observed phenomenon *didn't* happen since it can't reproduce the effect. ## Spells Spells are a very tricky thing to escape the physical box because they claim to be reproducible. That reproducibility puts the phenomenon of a spell they produce squarely inside the box of stuff science can look at. In order to allow spell with the current definition of science, you either have to deny common observation (as we see with the observer effect in quantum mechanics), or you have to deny a systematic description of it (as we see with the spontaneous event called radioactive decay). There is no possible way to describe the phenomenon of an atom of Carbon 14, for example, decaying into a Nitrogen-14 and an electron. We will never have a mathematical description of when that event will happen, because it has no cause. It is by definition, a spontaneous event. Another such spontaneous event is wavefunction collapse of a quantum entangled particle. So those real-world examples form the basis for allowing a spell: reproducible magic. Physics currently allows such things because we know about the quantum weirdness and radioactive decay, but we can describe them mathematically, so they are still inside the box of science. In order to take a spell outside the box of science, and put it into the supernatural, you have to remove the mathematical description. In other words, the effect your spell creates has to be reproducible, but not have any mathematical description. This is not terribly hard to do since math relies unequivocally on the equality sign. You can not describe *anything* with math when the right side and the left side are not equivalent. This is the foundation of all laws of conservation. An example: Since the question asks for the "minimum change," I will use an atomic-sized violation. Let's assume that when you snap your fingers (and you alone, no one else can do it), that then next time a Carbon-14 atom decays under your microscope, an electron flies off, but the Carbon-14 is still Carbon-14, and not Nitrogen-14. Here you have created a spell which very simply masks the aging of something, so that science will plainly see the beta emissions and count them, and they will THINK that the sample is X years old; but in fact, the carbon is not actually diminishing. You have created electrons from nothing. This little spell would effectively be a fun wizard college prank or cantrip, bacause you are creating something (an electron) from nothing, violating the law of conservation of matter and energy. What this trick could do is hide a stash of barley in an old jar, then ask your friends to enjoy some homebrew beer using your "fresh" barley 1,000 years later (you're a wizard, remember), and tell them with a shocked look on your face when the dusty ancient crumbs pour out that you "just packed that barley last week! What possibly happened? We must get this to the lab!" They will find week-old barley dust, and great fun will ensue in the journals and universities across the globe. ## Elixir of Life Again by breaking the equality sign, you can reverse the processes of entropy operating on your DNA as each cell undergoes mitosis. It requires only a tiny fraction of energy to override the energies which find their way into your DNA while it is unwinding and recombining. This DNA protection scheme is outside the box of physics despite being a repeatable and commonly observable phenomenon, because again it creates a small amount of energy from nothing, defying a mathematical definition. Every cell in your body repeats it so long as the potion is in your bloodstream, but the source of the repairs defy math. Modern science would fail to classify this as "natural" despite its repeatability. The Elixir of Life does not need any changes in physics to exist, it is already defined outside of science, and so can live harmoniously with the laws of physics as they are. And so long as the elixir itself can not be manufactured, there can be no argument saying "physics is broken." They can't repeat the Elixir; therefore physics is just fine. Physicists will be loosing many nights of sleep, but physics itself has no problem with an inability to put it into the box. It just ignores those things. # The smallest change to physics needed to allow magic is any arbitrary amount of inequality measured in any commonly observed and repeatable phenomenon. Either something from nothing, or nothing from something. ]
[Question] [ My hero lived his ordinary life until recently, when he realized that Magic actually exists. So far, he has been granted levitation for a short period, and invisibility for several hours. Both worked perfectly fine. Now, he has received a third gift from a magician. Immortality. My hero was told, that the immortality works like this: * The only thing that can actually kill you is getting your head cut off completely or starving to death. * Other injuries will still hurt, but everything else will recover itself without the need for surgery. * To recover, your body will need extra energy to heal. So if you are hurt, you have to eat and drink like crazy. * The immortality works on the principle of "quick, flawless regeneration". Each cell in your body is regenerated perfectly without any pesky side effects, aging included. * You cannot drown or suffocate. However, your body will need extra energy to work underwater or in unbreathable gasses. * Extra objects inserted into your body (like bullets or daggers) will eventually be absorbed by your body. And yes, that's extra energy cost. * You cannot get fat. If you overeat, your body temperature will increase to get rid of the excess energy. * The magician will check your progress in life after 250 years. As you can guess, the magician disappeared after telling my hero these basics. My hero is a 30-year-old male who has never had any type of operation which leaves something in the body (like hip replacement or a bone fracture, which needs screws to hold the bone together). He tried to cut himself, and it hurt as usual. The scar seems to be healing quicker than my hero is used to. My hero still does not believe in magic. Also, he does not trust this magician. However, if he is really immortal, he can make some long term plans. So, how to test if you are immortal? Yes, you can put a dagger to your heart ... but if the magician was lying (or immortality does not exist) that would be a really stupid test. Edit: This is happening in current world, current time, in one of First-World [Second-World](https://en.wikipedia.org/wiki/Second_World) countries. Apparently, [Czech Republic](https://en.wikipedia.org/wiki/Czech_Republic) seems to be still on the list of Second World countries... [Answer] # Start with the simple stuff Well, you have written a list of rules and most of them are non-fatal if tested. So you can start with the simple and "safe" stuff, and then move down the list. ## Objects are absorbed I have a slight objection to that one: absorbed as in **encased and kept indefinitely** or **dissolved and excreted**? Test: **Push a sewing needle into your arm**. Success: Needle is gone after some amount of time. Failure: Needle causes discomfort, infection, inflammation or otherwise hurt you. Keeping safe from failure: Visit a doctor and have the needle extracted. ## Cannot drown Test: **Jump into a pool** at the shallow end and crouch down. Bring a buddy if you wish for extra safety. Success: Still alive after 10 minutes with no ill effects. Failure: Feeling the usual feelings of panic and discomfort of not being able to breathe. Starting to get grey-out and tunnel vision. Keeping safe from failure: Stand up and breathe. ## Cannot get fat Test: **Eat excessively**. Monitor your body temperature Success: You do not get fat. Body temperature rises. Failure: You gain weight. Keeping safe from failure: Stop over-eating. ## Fast healing 1 Test: **injure yourself lightly**. See how long it takes to heal and if that varies depending on how much you eat. Success: Wounds heal without scarring or discoloration, and they do so depending on your food intake. Failure: Scarring results. Wound do not heal any faster compared to what they would normally. Keeping safe from failure: Stop injuring yourself ## Fast healing 2 Test: **Cut off some part of yourself**, like a centimeter wide flap of skin, as if say removing a birthmark or a mole. That cannot heal on a normal person without scarring. Success: The cut is healed without scarring. Failure: The cut is not healed without scarring. Keeping safe from failure: Sorry, you will have to put up with that scar. ## Fast healing 3 Test: **Donate blood** five days in a row. No normal person reacts well to losing five pints of blood in that short amount of time. Success: You do not experience dizziness or other signs of low blood pressure. Failure: You start to feel the symptoms of blood loss. Keeping safe from failure: Stop donating blood as soon as you feel the least bit ill. ## Fast healing 4 Test: **Cut off the tip of a finger** Success: The finger heals without trace of injury Failure: The fingertip does not regenerate Keeping safe from failure: Again, sorry, it is gone... but a fingertip is easy to live without. ## Fast healing 5 Test: **Stab yourself** in the lung Success: You heal without sign of injury Failure: You start experiencing great difficulty to breathe Keeping safe from failure: Call emergency services and have them patch you up at the hospital. Blame a mugging or something like that. ## Fast healing 6 I think you get the idea by now... [Answer] If all the rules have been explained to the hero I would suggest he **goes out and gets a piercing**. If I understand your rules correctly he would absorb the part of the piercing that is encased in his body and the hole will seal itself. This is not how normal healing would work at all, and if the wizard was lying (he isn't, but the hero doesn't know that) the hole would grow shut on its own again once the piercing is removed. [Answer] This is simpler than might appear to be the case. The person is now immortal or, at least, so he's been told. When if anyone lives long enough eventually they will die except, of course, if you're immortal. Essentially sooner or later anyone will be faced with circumstances that will kill a normal mortal person. Therefore, the best way to test your putative immortality is to continue living, preferably as if you're mortal, and when that fatal day comes and you're involved in a car accident, fall off a cliff, caught in a fire, drowned while swimming or whatever fatal incident occurs and you're still alive then you've tested your immortality. Basically if you're immortal you have all the time in the world to test your immortality. The odds are in your favour. Something fatal will always occur to everybody. If the test fails and you're not immortal you haven't lost anything (except your life and that happens to all mortals). You will have lived your life taking all the normal precautions of staying alive. Good luck to you fellow for doing so too. If, of course, it turns out you are immortal and you aren't dead, now you can begin to enjoy your immortality in style. Living normally long enough itself will be the best test for immortality. [Answer] You can't. It is clear from the OP that not only does the hero not trust the magician, but also that the purpose of any test is to prove whether or not the magician is lying. The magician may well be telling the truth with respect to any non-life threatening injuries (or behaviour such as over-eating), but any improved healing, even if proven and no matter how magical it may appear, does not prove immortality. Immortality can only be proven in such a situation in which the hero would be dead, otherwise. In other words, if the hero can avoid otherwise unavoidable death, then he is immortal and there can be no alternative proof. Furthermore, the hero has only been granted magical powers previously for limited periods of time - maybe the magician cannot grant any powers permanently. Immortality only makes sense if it is permanent (or at least significantly beyond a normal lifespan) - it cannot be temporary. [Answer] ### Cut off your little toe as a quick test It will hurt a lot. But you will see whether it regenerates. It should not regenerate and if it does you know that magic exists and you can be magically healed. That lends credibility to the story of the wizard. Either that or the toe will not regenerate, which is inconvenient but not really a big problem. People survive every day with far bigger problems. And most importantly: with the right precautions you should be able to survive this little test. ### Monitor your health over the next couple years Once this is confirmed you can just try to monitor your health as much as possible. You shouldn't see any difference in the upcoming 5 or 10 years, but you would expect *something* to happen if magic didn't exist. You can combine this with trying to get fat as hard as you can. This shouldn't really be a *big* problem to check. Even naturally thin people would get fat when eating nothing but chocolate for a prolonged time. ### Assume you are not immortal in the beginning Until the first real checks in a few years you should live your life as if magic does not exist. This is pretty much a safety net for you in case something normally deadly would happen to you. ### Expand your definition of "long-term" regularly After a few years your character will see that he can survive longer than others and he can expand the time horizon he is looking at. He is immortal, so it doesn't really matter when he starts. Every couple dozen years he can then increase what he perceives as "long-term". ### Conclusion All in all your character just thinks he has a very long life span. Not really immortal as he will never test that willingly. Maybe he will realize his immortality if some accident happens that would kill a normal human being. But that is certainly not his goal. --- ### Additional benefits This also prevents your character from going mad because of boredom. He does not perceive himself as immortal - he just thinks he has a very long life span. He still has to care for himself, monitor his health regularly in a very rigid fashion and look out to the end of his life. After all he can't be sure that tomorrow the magic is still there. He can just assume that he probably will live far longer than other people based on his experience up until that point. [Answer] Well, he could do it like in Flatliners: **have a doctor to stop his heart** and wait if his body comes back online before the "safe" amount of time for the brain to exist without oxygen passes. If it does not, the doctor resuscitates him. Of course, that could still mean there just wasn't enough time for him to heal the damage and then he'd have to find a different way. **This method is both fatal and reversible.** [Answer] > > You cannot get fat. If you eat too much, your body temperature will increase to get rid of excess energy > > > Just eat an aweful lot of calories and see if that holds true. Unless your hero already has a very fast metabolism or a genetic disposition for not taking on too much excess fat he will fatten like a piggidy-pig in a few weeks. As he can already levitate and make himself invisible getting money to pay for the foods (or the foods themselves without inconvenient middle-men1) shouldn't provide any big hurdle. 1Including but not limited to: Bakers, Butchers, Confectioners, etc. [Answer] There are a lot of good ideas here, little things like testing the healing factor, and I really like the pool test. But the really smart thing to do is to do nothing overt. The problem with some of the more severe overt testing methods is that they will be noticed. If you punch a hole in your lung and you don't want to die, you need to get in front of a doctor, and that means another person you have to convince to keep your secret. Drawing attention to yourself is likely to be worse than stabbing yourself in the lung. Attention means scrutiny, possibly from the authorities. That means long term plans are going to be harder to deal with. So maybe after a couple of checks that do not rely on somebody else getting involved, stop destruct testing and live your life as an almost mortal man. As a long term check, start taking "before and After" photos of yourself and someone you know. keep this up so you can compare the aging process. Start some long term planning. Diversify portfolios, start long term investments, get some swiss bank accounts. Bearer bonds. That sort of thing. None of these things is dumb for normal people, so this isn't going to attract attention. After about ten years, carefully comparing the aging photos, start looking into ways to move your wealth around. Keep on top of tech trends. Also, start looking into setting up false identities. After 20 years, start planning your death and orderly transfer of assets. Repeat as necessary, and try not to lose your head. [Answer] ## Over Exercise A simple ongoing test of a altered state would be to excercise at a level that is going to leave you really sore the next day. You get to stay really fit and you can test every day without too much long term problems. ### No proof possible My understanding of the scientific method you cannot prove what the magician said was true. That you can only be killed by the methods outlined. All you can do is find a method that will kill you and then unfortuantely you are dead. There is no absolute proof only disproof or running out of tests. [Answer] Hire someone to kill the magician. If he *can* make people immortal, he would do it to himself. Also, you aren't really immortal, are you? Anything that destroys your head, throat or stomach will kill you. so, if the magician wanted to do you harm, he doesn't need to trick you at all. But really, what would be the purpose of testing it? What suicidal thing would you regret not having done because you mistakenly believed it would be fatal? Saving someone you weren't willing to risk your life for? [Answer] Since the hypothesis to be tested is "I am immortal", there is no way to skip the "try to kill yourself" step. Since sticking the fingers in the plug, or whatever quick "suicide" attempt, in case of failure it is obviously stupid. Therefore the only way to test the immortality of the hero is to put him into some "slow killing" path. He can i.e. starts drinking heavily super alcoholics. This in a normal human would quickly damage the liver. After 1 year of this regime, the hero can have his liver checked. If it is still fit and healthy, he got the prove. If his liver is damaged, he can still quit drinking and go rehab. [Answer] You can never be sure by testing it using self inflicted injury. It could be a healing rather than immortality spell, or wear off after some time (years?), or not provide the full protection described to him After all, if you were the magician wouldn't *you* want a hero who, when you reappeared 50 years later to tell him actually he can be killed using something not obvious, and you plan to do so unless he does *exactly* what you ask? Also crossref the Norse myth of [Baldur and Loki](https://en.wikipedia.org/wiki/Baldr) - Baldur was made immortal and all his friends spend their evenings tryingto kill him for fun. The one thing that *could* kill him was a weapon made from mistletoe (a small plant). Unfortunately Loki didn't see a need to tell him or anyone else that minor fact, before passing such a weapon to one of the people playing the game of "use your weapon on Baldur" ...... Your hero's first quest (before or after whatever else he has to do) should be to find someone else learned, who he can trust, and who can tell him what's been done to him. I would suspect that whatever it is, is not known, in the whole cosmos, by only one person..... [Answer] Can you still get sick or ill? I'm assuming from the various other conditions you've listed (can't get fat) that you don't. In which case there is one quite easy method of testing this that shouldn't be fatal if it goes wrong; Eat some raw chicken. If you get food poisoning and are violently ill then you're not immortal, if you don't you may have just got lucky so try again. Repeat at least five times, if you don't get ill at all then the magician was telling the truth. The advantages to this are food poisoning is awful and very obvious, reasonably easy to self inflict but shouldn't be fatal or have any lasting effects on a healthy adult. Other things you could try (with various degrees of success depending on vaccinations etc.) are contracting chicken pox, measles, thrush or other skin conditions (admittedly some of those can have more nasty results if caught as an adult) or even attempting to contract a mild STD (not AIDS or HIV, just something like chlamydia or syphilis). [Answer] Especially if he's as skeptical as you make him sound (doesn't believe even after a rapidly healing cut), the most sensible strategy for him would be to just wait. If he isn't immortal, he puts himself at no extra risk and lives a normal life. If he is immortal, then after several decades he should have more than enough experience proving the truth of his immortality: no aging, fast recovery from injuries, etc. At that point he can make his long-term plans. And since his lifespan is infinite, the decades he waits to confirm his immortality are completely insignificant. Edit: Wait, I re-read your question, and you start by saying that your hero believes in magic because he has been given the powers of flight and invisibility, and saw that they worked. Then you say he still doesn't believe in magic after being granted immortality. So I'm not sure what level of skepticism I should be reading in this. [Answer] In some sense, we're all immortal - until we're not. That is, we've grown up with a set of rules that help us stay alive (and stay complete) for the longest possible time. Those rules say things like "don't ride a motorbike without a helmet and thick leather jacket" and "don't jump off cliffs" and whatnot. We learn these rules because people tell them to us, but also because we test them out when we're kids (falling out of a treehouse and breaking an arm, for example). Your hero just has a new set of rules - and even if he trusted the magician, he'd still have to go and discover those rules for himself. @MichaelK gives a good logical course of action to re-learn the rules of self-preservation, but even those won't really tell your hero what he can and cannot do. Over the hero's (now extended) life, he'll try more and more things and gradually find out what he can and can't do. For example, he might jump out of an upstairs window - for most of us that's survivable, but our hero seems to be able to do it with extreme ease. You and I would think "wow, that was close, lucky I only broke a leg - glad it wasn't worse than that". Our hero thinks "hmm, that was no big deal, let's try jumping out of a 5th story window now". So it goes on, until our hero works out what his new limits are. Presumably jumping out of a 100th story window would lead to such complete injuries that whilst survivable, our hero would still have a long recovery time. That might convince them that jumping out of an aeroplane without a parachute isn't worth the 'cost' of the recovery, even if it's survivable - especially if there's another way down, which may appear more difficult or impossible at the time. [Answer] Testing the drowning part is rather simple: just hold your breath. If you cannot suffocate, you will be able to hold your breath indefinitely, if you can suffocate you will pass out and automatically start breathing again with no ill side-effect beside a headache. (Pro-tip: do not try this at home! It's really uncomfortable if you are not immortal) An easy test for the invincible part would be to get infected with the common cold. If the wizard spoke the truth, then the infection should be defeated without any effects other than a major hunger. As that illness is highly infectious, not getting it if you really try is close to impossible. Asking someone to cough in your face might however cause socially awkward situations. Another test would be to find a sharp object and cut into the tip of a finger with it just deep enough to injure the skin. That part of the body is highly sensitive (it really hurts) and therefore measuring the time it takes to heal becomes very obvious as you get constantly reminded of the state of the injury. It usually takes about a week for such a skin penetration to heal completely, so if it is gone by the next day, that part seems to be true as well. Testing for true immortality like driving a knife through the heart I would simply skip. There is no logical reason to test that. Sooner or later there will be a situation where someone will test that for me anyways. And if it still hurts like crazy there is no need to know, because I would want to avoid such situations at all cost anyways. There is also the risk that I might pass out from the pain, and while my body would dissolve the knife I might not be able to eat/drink enough to support it, and then I'd die despite being otherwise immortal. The hunger part should be a dead-giveaway alone, as a sudden overwhelming hunger would be quiet obvious. As my body approximately heals that way - sadly without the immortality and perfect recovery part - I got some experience with that, if I get ill I eat about twice as much on the day before (my friends keep calling me Frostmourne). Excessive drinking would only be necessary if your body actually needs to replenish fluids, but not for skin/bone/organ regeneration. Or if the body would try to flood out an infection, which probably won't happen with this type of immortality as such infections would be dissolved magically. This form of immortality might result in the following side-effects: * Excessive fear of starving, because you need food to survive, but can't store it, because the body dissolves it. * Excessive fear of blade-like objects, because they could cut off your head. * Allergy-like reactions when the body tries to dissolve otherwise harmless particles like spores or car emissions. * Immunity to any form of drugs and/or medication, even those which could be helpful. [Answer] > > How to safely check if you are immortal? > > > Please, excuse me sir, but it is impossible! There is not a safe way to check if you are imortal or not! It is plain logical think. Do you want to know if you are imortal or not? Jump inside a active volcano, place your head straight in the path of a magnun 45 bullet or similar. Smoking for 50 year or more and dont have a lung disease is not a prove you are imortal, it is not even a prove you are immune to the cigars quimical. Some things are the way they are, basead on logic. Some times there is not a shortcut :) . [Answer] Wait, the only really sure check that is entirely "risk free", as in no more risky than his existing life, is to simply wait and see if he ages. He will probably run into situations which prove or disprove some or all of the rules he has been given by the wizard who has cursed him with immortal life but the ultimate test of his immortality is time. Anything else only proves he can heal not that he'll live forever, twenty or thirty years with *no* signs of aged decline should be convincing enough for even the staunchest cynic. [Answer] Get infected from diseases, such as *Cholera* or *TB* for which medicine exists. But don't take any medicine. If it cures by itself you are immortal. If the disease increases daily you should start taking the medicine. [Answer] **Visit a Hypobaric Chamber** [Hypobaric chambers](https://en.wikipedia.org/wiki/Hypobaric_chamber) are routinely **and safely** used for training people to cope with the effects of a high-altitude/low-oxygen environment: > > A hypobaric chamber, or altitude chamber, is a chamber used during > aerospace or high terrestrial altitude research or training to > simulate the effects of high altitude on the human body, especially > hypoxia (low oxygen) and hypobaria (low ambient air pressure). > > > One of the powers the magician claimed to bestow is: > > You cannot drown or suffocate. However, your body will need extra > energy to work under water or in unbreathable gasses. > > > In theory you no longer require oxygen as long as you have food (I assume that's what "extra energy" means). So all you need to do is visit any high-altitude training center with a hypobaric chamber, and pay them to take you and your dinner for a ride. Have them take you to an impairing but not-immediately-life-threatening altitude to start with, like say 25,000 feet. You sit and enjoy your dinner and you either start rapidly becoming impaired from the low oxygen levels (in which case the lab technician repressurizes you, or you grab the nearby oxygen mask, or whatever) or you don't. If you don't, the technician can gradually increase the altitude even further. Eventually you reach an altitude where a normal person would lose consciousness and rapidly die from lack of oxygen. If you remain conscious and unimpaired, then congratulations; you may not be fully immortal, but you do seem to be immune to suffocation and no longer required to actually breathe! **Why it's safe** Someone else operates the chamber for you and observes you the entire time. If anything goes wrong, they can rapidly restore pressure and give you supplemental oxygen. If they're quick you probably won't even suffer any permanent brain damage from the hypoxia. Just try not to break your nose when you pass out and fall over. You're also not exposing yourself to any exotic of potentially toxic atmospheres. You're just slowly removing O2 from the environment, and immediately restoring it the moment anything goes awry. **What are the risks?** Maybe the tech is incompetent or hates you for some reason. They lock you in the chamber, take you to 50,000 feet (good luck forcing the door open with the chamber under that much negative pressure), and go play Tetris for a few hours. You'd better hope you're *really* immortal. Or maybe the chamber suffers a technical fault, and depressurizes too much or cannot be repressurized when something goes wrong. *Probably* these things have failsafes built in so that things like that *mostly* never happen. **What are the limits?** With this method you only find out if you're immune to suffocation as long as you have a source of extra energy. It's possible that this aspect of the spell works as advertised, but others do not. I wouldn't suggest you do this, and then move on to the "shoot myself in the face" test. Better to do it, wait 10 years, and confirm that you're not aging instead. And then you just *assume* you'd pass the "shoot myself int he face" test, without actually trying it. [Answer] # You can't, and he's not. You can't *because* he's not. The only way to prove that he is not immortal is to die. As the wizard *said* there are conditions in which he can die, he is presumably not immortal - otherwise the wizard would not have felt the need to explain things that could kill him, unless the wizard is lying not about the immortality, but the mortality. This is just fast regeneration. [Answer] Ever see Flatliners? Get a medically trained buddy to stop your heart and see if it starts up on it's own, otherwise attempt resuscitation. The only way to test immortality is to die, there isn't a "safe" way to do that. How is this [magic] energy gathered/replenished to heal or survive underwater? If it's through food, hence starvation being a cause of death, magic typically requires a lot more calories than a person can eat. If it's replenished some other way, why would they need food to survive? Or a body for that matter? as long as they can gather magic energy they should be able to survive as only a head since biological processes aren't necessary to survive, evidenced by surviving underwater. [Answer] Why not just wait until the hero accidentally injures himself? Then he could eat a lot and see his body temperature and injury. [Answer] Since his body only need extra energy to work in an ambient filled with unbreathable gasses, he just need to close himself in a garage with a car engine turned on. If after some minutes/hours he only feel tired, then he is an immortal, if he start to not breath well (or feel some of the symptoms of the CO2/CO poisoning) then he can exit the garage and he is not an immortal. ]
[Question] [ I am time traveller with aim to make world better. Last time I went to the past, all I heard was: "Kill Hitler!" So I went to the past and I must tell you, [April 1945 was pretty loud in Berlin](https://xkcd.com/1063/)! After I returned back, telling everyone that I shot Hitler to the head on 30th April 1945, all I heard was: "You did not do any preparation? Seriously?!" So this time (pun intended), I want USA to be switching to [SI Units](https://en.wikipedia.org/wiki/International_System_of_Units). Why? Because I hate Fahrenheits. I hate hearing "Its just 20 miles away" without knowing how far it actually is. So, I decided to travel to the past and changing USA measurement system to lovely Celsius's and kilometers. However, I am not sure, if I can do it in single-event trip. Thats why I am asking this question: **Can you make USA to use International system of units in single-event scenario?** * Must be single-event scenario. My machine has energy left just for one return trip * Must be caused by external action or non-action (e.g. forcing someone **not** to do X) * Must result by United States of America using officially SI Units. * Since some may say that [US already defines measurements based on SI units](https://en.wikipedia.org/wiki/Mendenhall_Order), I care more about "commoners" than for official definitions. * You may assume I am able to convince up to ten people (if group meeting needs to be done) * You may assume no one will think that I am time traveller (I will wear proper clothing and talk proper language, including its pronunciation) * Assume I can stay up to one month in the past, before I need to return back to my own time. * I want to return back to my own time alive. Therefore, I do not want to do anything involving risking my life (examples: Helping to fight off someone or jumping in front of a person to stop the killing bullet) * I do not care about historical consequences. As long as there will be a state recognized as the USA, placed somewhere in the current USA-area and it will be having people using "normal" units, that is all I care about. * No, I will not tell you how my time machine works and if it has any flaws. [Answer] Stop one ship from either sailing into a storm or (later) being taken over by pirates. In 1793, Thomas Jefferson ordered a set of instruments from France that would let the US calibrate to SI units, but the ship hit a storm at sea, blowing his ship into the Caribbean. There it was attacked by pirates (British privateers). The materials never arrived. By the time France sent a second set, US had a new Secretary of State who didn’t like metric system. You either need to delay the ship departure (so it misses the storm) or help take down the pirates. Minimal intervention. Details: * [Washington Post](https://www.washingtonpost.com/news/speaking-of-science/wp/2017/09/19/pirates-yes-pirates-may-be-why-the-u-s-doesnt-use-the-metric-system/?utm_term=.044a358ca5cf) (Paywalled) * [National Public Radio](https://www.npr.org/sections/thetwo-way/2017/12/28/574044232/how-pirates-of-the-caribbean-hijacked-americas-metric-system?t=1539696059136) (Open) ### Background information for the well-prepared time traveller * Jefferson, Congress, and weights and measures, with mention of the missed window of opportunity on pp. 21–22: + Charles F. Treat (1971). "Toward a more perfect uniformity (1607–1860)". *A History of the Metric System Controversy in the United States: U.S. Metric Study Interim Report, Volume 13*. U.S. Department of Commerce, National Bureau of Standards. * Joseph Dombey, the Frenchman with the task of delivering the first set of official copies of the standards to Jefferson: + "[To Thomas Jefferson from Joseph Dombey, 1 May 1793](https://founders.archives.gov/documents/Jefferson/01-25-02-0577)". *Founders Online*. U.S. National Archives. + <https://fr.wikipedia.org/wiki/Joseph_Dombey> * Louis Chambaud (1787). *Chambaud's dictionary : French and English and English and French. Containing The Signification of Words, with their different Uses ; The Terms of Arts, Sciences, and Trades ; and The Constructions, Forms of Speech, Idioms, and Proverbs used in both Languages*. London: A. Strahan, T. Cadell, and P. Elmsley. OCLC [642509248](http://www.worldcat.org/oclc/642509248). [Answer] Had the [*Metric Conversion Act of 1975*](https://www.gpo.gov/fdsys/pkg/STATUTE-89/pdf/STATUTE-89-Pg1007.pdf) been drafted differently, with concrete milestones and requirements, and an intent not just of adoption of metric units, but adoption of *existing international standards based on metric*, it might well have been the turning point. Having lived through that period, I believe the most significant factor was that it treated treat metric conversion by adopting of dual units, rather than wholesale adoption of related international standards. But it would have required substantially more work and change in the short term than seems to have been politically acceptable. But instead of mandating a schedule for use of international standards in interstate commerce, it was organized as a voluntary effort, and administered without much urgency. U.S. Government agencies did make efforts to comply, e.g. contracts after 1976 were written in metric units. But rather than adopting standardized ISO paper sizes such as A4, it continued to order it's traditional paper, by converting inch sizes to fractional metric (e.g. government-letter size was then 203.2 mm × 266.7 mm). This approach seemed to make metric seem harder than it might have otherwise been. Metrification required more than precise numerical conversions. Changing to new standards which utilized rounded values was more successful, such as the now ubiquitous 2-liter soft-drink bottle. By 1983, (less than 10 years later) metric standards were still not widely used in everyday life, and two American journalists have been commonly cited as the force behind ending the efforts of the metric conversion board. [Answer] I know too little of the internal US affairs, but let's take a wide swing. # Help Napoleon A paramount thing in making Napoleon I lose the war was the [attack on Russia 1812](https://en.wikipedia.org/wiki/French_invasion_of_Russia) that eventually lead to the first defeat of Napoleon's forces by the [allied forces](https://en.wikipedia.org/wiki/War_of_the_Sixth_Coalition). Notice UK being part of the coalition. Some time before, however, Napoleon was seeking alliance with Russia and was obsessed with [attack](https://en.wikipedia.org/wiki/Napoleon%27s_planned_invasion_of_the_United_Kingdom) or at least a blockade of the United Kingdom. So, open options are: * Derail the the Britain-Russian alliance in the context of the [Third Coalition](https://en.wikipedia.org/wiki/War_of_the_Third_Coalition) (1805). * Change the outcome of [Trafalgar](https://en.wikipedia.org/wiki/Battle_of_Trafalgar) (1805). * There *was* some kind of a Franko-Russian alliance in 1807 in the context of failed Middle East alliances. * There were (two in fact!) [marriage proposals](https://books.google.de/books?id=k5UaAwAAQBAJ&pg=PA21&lpg=PA21&dq=napoleon%20first%20language&source=bl&ots=PamWY4kGMy&sig=VuNbNGwd5Ik99D6herWxslPhJCg&hl=en&sa=X&redir_esc=y#v=snippet&q=marriage&f=false) from Napoleon to closer Tsar's relatives, 1808 and 1810, if my memory suits me right. Although there was some kind of economical discrepancy, following a peace treaty that was not-so-profitable for Russian trade, it's nothing that cannot be fixed. Basically, the goal here is either never let Napoleon invade Russia or to split UK from the (historically) winning coalition or to make France invade Britain earlier and/or more successful. # The question was about SI though What does all this has to do with SI? Well, SI was invented in France and France was its biggest proponent for quite some time. Taking UK out of political equation would result in much less cultural influence on the USA. Arguably, much fewer Irish people would move to US. But most importantly, the USA-France connection, that was quite warm at the foundation of the USA, would persist and be much, much stronger. Those new United States might end speaking French or been swallowed up by Canada or what not. They might even not expand to the full size of the our realm's US or do it slower. (I doubt the French Empire would have too much interest in California, but who knows for sure?) As one of the hallmarks of French cultural and technical expansion to the US, wide adoption of the SI would surely follow. # The aftermath After the time-traveller returns back to his time, he'd notice *severe* differences in the US life. Cities might be named differently, have kept their "non-British" designations or not even exist. (Say, NY is New-Amsterdam.) Currency might be called differently and for sure have different design and different people on it. People talk French or at least have much more French than Latin or UK English loanwords in their language. And yes, the [flight levels](https://en.wikipedia.org/wiki/Flight_level) are stated in meters world-wide. Mission accomplished. [Answer] Travel back to the early Roman Empire and start producing thermometers calibrated to Celsius, precise maps using your knowledge of geometry, precise clocks, scales and kilogram blocks. Explain how good it will be if the Romans used a standardised system across their empire and encouraged their trade partners to do the same. Maybe predict a few events to convince them of your brilliance. By the time Fahrenheit is born nobody cares about his new way to measure temperature. Imperial measurements never existed and the US would have no choice. [Answer] Well, since you're already familiar with Hitler in your time travels, and [Germany had been using the metric system since about 1870](https://en.wikipedia.org/wiki/Metrication#The_German_Zollverein), the answer practically presents itself: # Help Hitler win WWII, and occupy the USA too (Optionally, kill Hitler afterwards, just a little later than the first time) I *think* the USA would still be called something very similar to "USA" (since I think occupied France was still called [something like](https://en.wikipedia.org/wiki/German_military_administration_in_occupied_France_during_World_War_II) "Military Administration in France" (German: Militärverwaltung in Frankreich; French: Occupation de la France par l'Allemagne)) And it shouldn't be impossible to do, there's [lots of ideas on how he could have won](https://duckduckgo.com/?q=how+hitler+could+have+won+world+war+ii&t=h_&ia=web), but besides convincing him to change a bunch of strategies, maybe just go straight to having him research nukes first... maybe by convincing Hitler than scientists (specifically nuclear) are his only chance. * [A discovery by nuclear physicists in a laboratory in Berlin, Germany, in 1938 made the first atomic bomb possible, after Otto Hahn, Lise Meitner and Fritz Strassman discovered nuclear fission.](https://www.history.com/topics/world-war-ii/atomic-bomb-history) So they've already got a leg up on the world. * [Apparently](https://www.atomicheritage.org/history/who-built-atomic-bomb) "Over one hundred scientists who had recently fled from the Nazis contributed immeasurably" to building the atomic bomb, so have him stop chasing out scientists. [Answer] Remember the Mars probe that was lost because someone forgot to switch between metric and non-metric? Infiltrate NASA and cause the first moon mission to fail because of that. Even better, have the rocket explode in a populated area. [Answer] **Put it in the Bible.** Travel back to the aftermath of Christ's death, before the apostles spread out. Present yourself to the apostles as a prophet/emissary. Do a couple miracles to establish yourself, using modern technology which should be indistinguishable from magic. Then present your revelation. Distribute printouts. At least a couple of them will write it down in their gospels. (There's twelve of them, but not all will go on to write gospels. Convincing ten is more than enough) The revelation includes the units of measurement to be used by God's people: * The Celsius scale. Fresh water at sea level freezes at 0ºC, and boils at 100ºC. * The meter. 1/Nth of the distance between specific features of two monuments which survived to the modern age. E.g. the door of a temple, the vomitorium in the Coliseum, the central pillar(s?) in the Pathernon's facade. If you can give them two familiar monuments that's better, if you can score a round number that's best. But an arbitrary number and faraway cities will work just fine, tell them it's "about the length of a step of a man" and give out meter-long staffs to kick-start rough use, later scholars will refine it. * The liter. The volume of a cube a tenth of a meter on all sides. Give out liter containers. * The Kilogram. The mass of a liter of water (distinguishing mass from weight to ancient fishermen may be hopeless, so you might want to go with the "weight" of a liter of water). Give out 1kg weights. * The standard multipliers. Kilo, mili, micro, the whole thing. * The second. The time it takes a 1kg sphere of pure iron to hit the ground when dropped from X meters. Hours and minutes defined relative to seconds. (Are you sure you do not want to use one of those nerdy alternative 10-based time scales instead? Whatever.) Give out minute-long and hour-long hourglasses. Note that this is far too much information to hold in their heads, so the printouts are important. No way early Americans will ignore the units mandated in the Bible. I don't know anything about the history of imperial units, but they may be pre-empted altogeter since the British were Cristians since before the Empire. [Answer] To quote the [accepted answer](https://worldbuilding.stackexchange.com/a/127534/25872): > > In 1793, Thomas Jefferson ordered a set of instruments from France that would let the US calibrate to SI units, but the ship hit a storm at sea, blowing his ship into the Caribbean. There it was attacked by pirates (British privateers). The materials never arrived. **By the time France sent a second set, US had a new Secretary of State who didn’t like metric system.** > > > That Secretary of State was [Edmund Randolph](https://en.wikipedia.org/wiki/Edmund_Randolph). Remove him from the equation (assassination is probably easiest) just before he's appointed to his new position in 1793, and Jefferson (his predecessor) would most likely remain on in the position, or at least have enough of an influence to ensure that the second set of metric instruments would be adopted. Note that Randolph did accomplish some quite noteworthy things before his appointment as Secretary of State, hence his death should only be scheduled to occur after those. As noted, just before his appointment would be safest. [Answer] **Edit** *I misread the OP's question and didn't realize he was looking for an historical event. I apologize. This isn't an answer to his question. But I had a lot of fun writing it, so I'm going to leave it up. Please don't vote for it. Cheers.* --- **Not that I can believe (as an American)** In reality, the issue is *cost.* It's the consequence of a capitalistic society combined with a representative government. **Senator:** We need to stop using multiple systems of measurement! **People:** OK, we can see the value in that... **Senator:** It means changing our schools and businesses! Everything from the paper we use to the measuring cups in our kitchen drawers! Think of the jobs! Think of the opportunity! **People:** Wait, my measuring cups? Do *you* even know what dry measure is in the metric system? My paper? Who's going to pay for all this? **Senator:** We'll need to pass a temporary tax to help subsidize business and schools to affect the change! **People:** There hasn't been a temporary tax in U.S. history!1 I'm not voting for that! Government hasn't used a dollar efficiently since day one! Heck no, we won't go! And after the protests have died down, we're back at square one. We've had the same problem with adopting credit card security measures in use in Europe for years and years — the cost to convert everybody is whomping enormous, no one's willing to pay the price, and no one's willing to vote for anybody who's willing to committ to deficit spending to make it happen. The credit card industry finally forced the issue by making businesses responsible for fraudulent spending if they didn't change — and two years later there are a lot of businesses that still haven't changed. Has there ever been examples of this happening successfully? Oddly, there are (kinda). The Feds outlawed the manufacture (and eventual sale) of 40W, 60W, 75W, and 100W incandescent light bulbs (a lovely attempt by the environmentalists to force the citizenry to reduce their power bills. You'd be surprised what we fight against). It happened — and while some people cheered, many *loathed* it. It also happened with the conversion of TV broadcasting from analog to digital. The only way it happened was by the Feds giving away free analog-to-digital conversion boxes. **But converting the way we measure things?** In the end, people don't care about light bulbs so long as they fit in the lamp and do their job. Kinda ditto with TV. You don't actually need to *think* about anything (and Americans as a people aren't the best thinkers, not since WWII anyway). On the other hand, swaping out all our rulers, scales, forcing us to think about carrots in terms of grams.... (Although it has worked for soda. That's a curiosity all by itself....) So, despite our entire scientific community using SI units, and pretty much all our cars using metric nuts and bolts, I honestly can't see any way to force such a change on the people other than the government simply choosing to do it — and whichever political party is in power at that time can expect to loose the presidency for 8-16 years because people will absolutely *howl.* Suddenly all of their great-grandma's recipies don't work anymore. **Unless...** Unless the government simply chose to mandate that all labeling of all products had to be metric-only. After that it would take (literally) 100 years to get everyone on board, but it would eventually happen. I think. (Oh, people would *howl.*) Yeah. We're funny people. --- 1 *Whether there has or hasn't isn't relevant. We don't perceive that there ever has been one. It's a very personal thing.* [Answer] Even though the website which displayed recent (1990s) plans for an invasion has disappeared, you could go further back to 1927 and convince [Canada](https://bigthink.com/strange-maps/in-1921-canada-developed-a-secret-plan-to-invade-the-us) to follow through with its invasion plans - and win. Advantage: we all use the metric system. Disadvantage: poutine, DunkinDonuts never exists as TimHorton's covers the continent. [Answer] Convince the Warren court that it is a moral imperative for the country to adopt metric. You bypass potential political objections, you only have to convince 5 people. For extra assurance you can convince the other 4 justices plus the president. The SC will rule all other measurement systems unconstitutional and the president will enforce the change. You accomplish the change with minimal impact in everything else and you make the change late enough that the use of an inferior system doesn’t cause America to lose any major wars. [Answer] I would talk to whoever is in charge of the US at the time of the invention of the metric system and tell them to adopt them as a way to show patriotism: "imperial units are from those nasty Brits, we want none of that!" Calls to patriotism are the easiest way to get anyone to do anything, beside perhaps, calls to faith. [Answer] # Torpedo the Mayflower You would have to literally wipe out every American and eradicate all of our history to get us to adopt the French Revolutionary "SI" system of measurement. We will fight to the last man, fight on the beaches, fight in the hills, fight in the forests, etc, etc,... If you could take a submarine with you and simply torpedo every ship carrying English colonists for a few centuries, leaving the French to settle North America, then you might pull it off. Good luck, *ami*. ]
[Question] [ Say you have a hollow sphere, about the size of a (small) grapefruit, comprised of a (let's say red) top half and a (let's say white) bottom half. There's an articulated lid, and an LED on the front. Most importantly, it fits in the pocket of your pants (or skirt, if skirts have pockets). Now, somehow, I need to fit 0.001 - 999.7 kg worth of monster in this sphere. What is the least physically egregious way to do that? Let's ignore for a second the issue of convincing the beastie to undergo whatever process is required. Open to creative solutions, including exotic matter. Must be if not-science-based, at least not offensive to reality. [Answer] You don't... exactly. The Poké Ball—er... hollow sphere—isn't actually containing the monster. It is merely the user-interface for a teleportation device to transport the monster from its nice (and environmentally conscious) pen to where you are (and back again later). Sure, you might need a [Heisenberg compensator](http://memory-alpha.wikia.com/wiki/Heisenberg_compensator) in order to "scale up" quantum tunneling to a macroscopic level... but at least your monster isn't cramped in a tiny little inhumane cell! (While we're at it, is it politically correct to call them a "monster"?) [Answer] Because of conservation of mass your monster beast will still weigh just as much before as after, so assuming the monster *is actually inside it* and you're not cheating your requirements, you're going to have rather large holes in your pockets from the larger members. This already seems like an issue. However we could, technically, compress the monsters. Matter can be obscenely compressed with the use of a singularity, or black hole. We'd need to come up with some manner of creating a black hole in the small sphere. While this would kill the monster, getting the monster *back out* wasn't a requirement, so let's not focus on that too much. What we should focus on is that, unfortunately, the smallest black hole we're yet aware of is 15 miles (24 kilometers) in diameter. So not only are we going to have to construct your pockets out of some exotic material to not collapse given the weight, and some way to negate the gravitational forces associated with the singularity, but also we're going to have a very large ball. Really seems like a bad idea, doesn't it? Unfortunately that's about your only option for compressing matter as much as we need to. So basically we can't really have the matter inside the sphere. What's the alternative? Well, we need to store the matter *elsewhere.* I'm not sure how much of an affront of science you consider worm-holes (they're currently very loosely theoretical with no proof that they exist, or definitive models of how they would work) but we could toss a wormhole in one of them, and have your monsters chilling out at the pocket monster center elsewhere. This way we avoid compressing the mass, we avoid the weight issue, and we skip black holes altogether. Also PETA just called, and they want a word with us both. What time are you available? [Answer] **Digitally** Assuming you also want these monsters to be able to be transported digitally, to, say, some dude's PC, and stored in a database, you will be working with digital data anyway So a thing these balls can do is just take a digital scan of the specimen (it should be a destructive scan if we want the monster to "disappear") and then just store its data. And then when we want to get the monster out of the ball, it could just more-or-less instantly 3d print the monster! [Answer] Pocket dimension is what I would go for. Basically, a spherical TARDIS (minus travel). **Edit:** Semi-scientific explanation to this system. Pocket universe is not fantasy if you submit to additional dimensions. Imagine you are a being of a single dimension, using vertical space (the additional second dimension), you can store more objects than the space you are using in your single dimensional universe. Same will apply to our reality if there are additional dimensions. I am not well versed in string theory but I am sure string theoreticians can come up with a solution to that problem. [Answer] I think we can do this without even breaking the known laws of physics, if we're allowed to bend the rules *a little.* The sphere wouldn't even be all that heavy, which is a problem several other answers ran into. Pack the sphere with nanomachines capable of rapidly manipulating matter on the molecular scale, and with a very-high-density hard drive. When you "capture a monster", the nanomachines dissasemble it into carbon dioxide, nitrogen, and other unobtrusive gases, and they record the original position and context of each atom. Then, when the trainer wants to summon the monster for an indisputably ethical gladiatorial bout, the same nanomachines suck in air from the environment and use it as building blocks to reassemble the monster that they originally captured. (Trace elements not present in the air might be held in storage in the sphere, I suppose.) Granted, it requires a bit of sophisticated philosophy to see this as the monster existing "in" the po- er, sphere, when all that's there are ravenous nanites and a hard drive of chemical data. Also, the nanomachines would have to work *very quickly* in order for the monster not to come out as a tortured mess. And its an utterly horrific concept. But there's no *fundamental physical barrier* to such a device, I think. [Answer] As you mentioned that Exotic Matter is a possibility, I only felt as though this answer was justified. Due to the discovery of Exotic Matter (or XM) by the NIA at their cover operation of CERN and the foundation of the Niantic Project, these pok--- spherical balls could be made out of this Exotic Matter. Within each of these balls lies a Portal akin to those leaking Exotic Matter into our universe. However, these Portals are highly mobile and allow for monsters to travel back and forth between the two universes. Humans and other non-monsters could be kept out of this universe by physically being unable to go through these Portals. Alternatively, they can never return and, therefore, nobody even tries to go into them (if you go this route, you could possibly have these "trapped" people re-appear in XM patterns through Portals all across the world -- or, they could be antagonists through whatever means). Monsters are stored in this alternate universe where the benevolent (according to one of two factions on Earth) aliens known as Shapers decide to take care of them by placing them in idealized environments until they're summoned by their Tra--- master back into the main universe. This solution also allows these Pok--- monsters to be stored in PCs. As it has been proven that phones and other electronic devices can control and manipulate XM, PCs (and cell phones) can create and destroy these items, and upload their schematics to a private cloud for later storage. XM released only goes back to being stateless and in a seemingly random pattern, so it takes energy (battery life?) to "hold" the proper state for these items. And, best of all, they fit into your pocket as long as a phone fits in there. Items that can be used on these monsters can also be set up in this same way. As long as they are made of XM, they can be easily stored into the cloud. Who knows? This may eventually lead to the creation of a "game" where people can manipulate and trap these Monsters (through the use of XM) that are somehow invisible to the naked eye. Similarly, it could also spawn a "game" related to the *ingress* of Exotic Matter through Portals into our world. [Answer] Monsters are made from atoms, and atoms are mostly empty (99.9999999999996%). All you need is a uh... *Maxwell compensator* which temporarily inhibits electromagnetic interaction. Then you can shrink any object to 10-13 of its original size. Once the inhibitor is deactivated, objects will automatically grow to their original size again. As a free bonus, this also prevents a living creature from suffocating (either because there is no air inside the ball or because oxygen atoms are too big) and from starving, since the process should reliably stop any kind of chemical reactions (including biological ones), thus basically "freezing" whatever object or creature you put in. No food nor air needed, and no aging. [Answer] Don't focus on the ball - focus on the monsters! It's pretty implausible to convert living, organic creatures into data and back again, but what if the monsters are not actually living beings, but rogue nanomachine swarms who *think* they are living things? They are scattered throughout the environment, invisibly floating in the air, waiting for a signal that tells them to join together and take form. When a different signal is given, they break apart and transmit their data to a device. Without a human to give them commands, they simply live in the wild like animals. Now the question is, *why* would anybody create these machines? Well, maybe they wanted to take augmented reality gaming to the next level and something went horribly wrong... [Answer] [Pym particles](http://marvel.wikia.com/wiki/Pym_Particles). They have only discovered the ones that make things smaller so far. But one day they should be able to turn those pocket monsters into real monsters! [Answer] I think your best guess would be the same technology principle used for teletransportation. You need a very powerfull nuclear fusion central in the sphere and a interface that can store all the molecular information from the monster. Then, you desintegrate the monster untill you need it back. When you press the button, the sphere recreates the monster with the information previuously stored. And yes, I know this has the same moral implications than the teletransportation. [Answer] Create a two dimensional world and utilize the upper dimensional trick known as perspective. Any object fits over any other object when the perspective is changed unevenly via a jaunt to a higher dimension. [Answer] So why don't you just dry them. A living creature is mostly water. So you can somehow evaporate all the water from your monster. It also would weigh much less. And in your sphere you would have something like powder. When you need to actually retrieve your monster from the ball it will condensate water from its surroundings, air mostly. [Answer] This is an insane solution, but it could very well work. Simply give your characters or a particular rich character the ability to tap into the very laws of physics and "recode" them. Then have them tweak it so that energy can be created via a very obscure reaction/perpetual motion device. Then of course, it would be patented. This machine can be used to then create an energy field around the monster. We do not want to kill the monster so we simply counteract all outside and inside forces in such a way as to make it seem like a parallel dimension (it would be like putting a force field that counteracts the forces between two impacting cars. In theory, they pass through each other.). Then the monsters do not sit inside the ball. They simply sit in a field that allows them to pass through everything off to the side. But then they would freze to death, right? Well... Not really. We just mimick the heat with energy from the field. In fact, this field could mimick any environment we want the creature to be in. In fact, we could even make it seem like the monster never went into the ball, and make it believe it is in the wild! **TLDR: Use an energy field that allows them to pass through matter whilst mimicking whatever environment we want by changing the inner energy of the field.** And I just realized... ***These balls could be used for human interrogation... Just make them think they escaped capture while monitoring*** So, now you have a pokeball design, and a way it couldve developed (as an interrogation technology possibly used in a cold war or similarly espionage-filled era). Also, this occured to me after writing this, but since I just gave your character(s) the abilty to recode physics, biological manipulation combined with the recoding of certain obsucre physics could account for the existence of these monsters. In fact, you could even claim that these monsters "just started appearing one day", and that nobody has any clue why. It could serve as a plot device, if you wish. [Answer] The official NINTENDO manuals for the first pokemon fames state that the pokeball effectively shrinks the pokemon, and the actual pokeball itself is just a pleasant environment. Think of it like how Ant-Man's suit worked in the comics, it basically makes the atoms smaller and therefore lighter (I know its a really weird thing, but... comics are super weird). [Answer] An option might be to go Matrix style and extrapolate on the current trends: Mankind falls in love with virtual reality and technology. By the 2030s, every human was equipped with immersive enhanced reality rigs. Landscape and people are photoshopped in real time, rigs generate a wide range of sensations for their users. The virtual side of "reality" becomes more attractive while the "real" side become stalled and inhospitable. Pollution and environment degradation push people's lives ever faster towards full virtual reality environment. Life in the "real world" becomes increasingly irrelevant. Work happens exclusively in VR, interaction with the physical world being the purview of specially built robots controlled from a fully distributed VR environment and abstracted away. People's "real" bodies end up docked in 24/7 in "safe" facilities while they go about their days in a completely virtual environment. Within a couple generations, everyone has forgotten entirely about the existence of the physical universe and of their own bodies. Machines handle the reproduction duties and plug new human units on a regular basis to replace existing worn-out human units. By the time your story begins, the "real world" **is** a virtual world and no longer subject to the same laws of physics. For all we know, it has already happened. ;) Now, you can have your pockets full of monsters and if you want to store them in some quaint old-fashioned, grapefruit-sized, red-and-white container for the sake nostalgia, who is to tell you different? Our current reality and its laws of physics didn't account for this perfectly reasonable application, but Reality® Pack Version 3.5b2.08 makes it a breeze. Think like a manager. If reality isn't consistent with your requirements, reality must be wrong. You just have to upgrade reality. The scary part is that it's a whole lot more realistic solution than storing genetic information and 3D printing monsters on demand or extracting monsters from a pocket dimension of some kind. [Answer] # version 1 The spheres are in reality equipped with hypodermic needles that releases a strong drug filled with nano-bots that plugs into your nervous system, after their first usage you get connected to the Collective, a network of humans, creatures and other aliens connected with each other with the solely purpose to expand the network by using the computational power of the network and the drones creatures plugged into the Collective. The network force you to a wild catch of monsters to train them, this rather time-consuming but mind effort-less task is designed to keep your brain at low usage in order to use the remaining computing power for the Collective, you will not notice you are part of such a network. # version 2 Each ball is crafted inside a huge particle accelerator (that's why they are costly) and actually opens to a curved space where time flows really slow (and that's why weight would not matter, it is just reduced by the time flow). Consider it a white hole, or a naked singularity. Rumors about accidents are known (vanishing buildings, especially with outdated balls). [Answer] Consider other events that have occurred in Grapefruit-Monster universe as show in the games, anime and manga. These events included time travel, teleportation, evolution where a being increases its mass by 20 times, discharging vast quantities of liquids, projecting cold, etc. I believe that monsters themselves have the ability to access pocket dimensions. The human invention of the capture ball just mimics what the monsters can do. Perhaps the first version of the capture ball was to duplicate the monster eggs. Most of the monsters hatch from eggs. All eggs are the same size and weight, and yet a monster will "hatch" at full size and mass. Consider the game mechanics of evolution: a monster goes into battle and fights, or observes, repeatedly. Said monster gains experience until it decides to "evolve" and increase its mass by a factor up to 9999 times. Living nuclear weapons doesn't come close to describing how scary that is. Suppose instead that in the course of training, mass is being shunted to the monster's pocket dimension. At the moment of evolution the stored mass is added to the monster. The various title names were variations of pockets and monsters, yet I never noticed a capture ball being put inside a pocket. Perhaps it was intended to be pocket dimension capable monsters this whole time. [Answer] The answer is very simple to me. Just take my preferred opinion on how the po-, uh, grapefruits work. Each on converts the pokemon to energy and stores them. Occasionally the energy overloads the storage device, and a failsafe converts the energy back into the creatures. These energy beings can also be sent from place to place. [Answer] Well as per me, the ball is just an energy converter. We all are energy in some sort of form. So, if we have a device which can convert that energy we can put it into another form, like in the form which we can store in the small ball. As we can store energy in a ball, we can also manipulate the stored energy to make genetically developed creatures like pokemon. ]
[Question] [ [Jimmy is an Eldritch Monstrosity.](https://medium.com/universe-factory/a-horror-named-jimmy-1fd07b2cf9be) Jimmy has a Red Ball. Jimmy wants someone to play with him and his Red Ball. All of Jimmy's friends are busy trying to Overturn the Cosmic Order and bring Chaos to all of Existence. Jimmy thinks that humans will play with him and his Red Ball. Jimmy once tried to talk to a human via telepathy. The human went mad and died. Jimmy once tried to reveal his True Form to a human. The human went mad and died. Jimmy once wrote a note in his native tongue and passed it under the Desk of Eternity to a human. The human read it, tried to use some of the words to open a Gateway to the Nether Realm, went mad and died. Jimmy once opened a portal to push his red ball to a human. The human was infested by an Alien Mushroom, killed his family, started a worldwide cult, mutated into a Writhing Mass of Tentacular Doom, slaughtered three dozen investigative reporters, went mad and died. Jimmy was sad. Can you help Jimmy? --- Given that humans have a tendency to go mad or otherwise suffer grisly fates when exposed to beings from beyond reality, how could an eldritch horror interested in peaceful communications with humanity **reliably** do so? As with many mythologies featuring such creatures exposure to an eldritch horror isn't an automatic guarantee of insanity, but prolonged exposure to them certainly increases the chances of having an existential crisis or being possessed by Something from Beyond. Assume that individuals have different levels of resistance and that the more direct the form of interaction the less it will take before Badness happens to the Mere Mortals. Any method or methods that would reduce the incidence of people going mad and/or the risk of them causing harm to themselves or others will be considered. Organisations of humans or using technological solutions are allowed I'll be ranking the answers based on how well they enable Jimmy to play games (nice ones, obviously) with his new human friends, and how few casualties they're likely to cause. [Answer] ## [By computer](http://gunnerkrigg.com/?p=862) Clearly, humans can't handle direct contact with Jimmy, so what's needed is a layer of separation. Fortunately, humans have recently invented a way for two beings to have a form of interaction while being nowhere near each other. All Jimmy needs is a remote cabin in the woods, a laptop, and a satellite dish. Now, putting Jimmy online is obviously risky business. For best results, Jimmy should abide by some strict ground rules: * Before jumping in: observe, observe, observe. Learn how humans interact and imitate it. Make it your goal to pass the [Turing test](https://en.wikipedia.org/wiki/Turing_test). * Stay away from Snapchat, Instagram, and Facebook. ("It's called *Face*book, Jimmy, you can't join if you don't have a face...") Don't even *think* about getting a Skype or YouTube account. Textual communication only. Keep your default profile picture. * Limit yourself strictly to existing words from a human language, written in [printable ASCII characters](https://en.wikipedia.org/wiki/ASCII#Printable_characters) (and by all means, avoid the Z̪͙̞̟̖͖̖̈͋̒͆͊͠a̧͓̜͍͒ͣ̐ͮͣ̋l̀gͧ̂̎̅̅̆͂ő̤̈ ̧͓̳̘̭̦̖̫̾͑̋t̘̳̖e͔͉̗͆ͦ͋̓x̪ṭ͓͖̫̖̗ͧ̃). * It's best to look for one-to-one forms of communication: ~~if~~ when you slip up and say something in your native tongue (we all make mistakes), you've only driven one person insane, not 500. * Above all, *never* ask someone you met online to meet you in person. Ever. This will probably still be a process of trial and error. But with luck and determination, Jimmy will get better at "speaking human" over time, until he can chat with someone and [hardly raise any suspicion at all](https://www.xkcd.com/1530/). As to playing ball, that unfortunately falls afoul of the "no meeting in person" rule. However, it is possible that some kind of [virtual ball game](https://en.wikipedia.org/wiki/Pong) could be arranged. --- [@ghosts\_in\_the\_code](https://worldbuilding.stackexchange.com/users/5147/ghosts-in-the-code) asked whether it has to be a simple 2D video game. Basically, yes. This is the only safe route. (More generally, the game has to be entirely created by humans, with little to no customization available.) To the objection that this level of interaction will not give Jimmy happiness, I respond: A mere mortal such as myself cannot guess what will or will not give Jimmy happiness. However, the OP wants to know "how well [solutions] enable Jimmy to play games (nice ones, obviously) with his new human friends." If Jimmy wants to play with humans, and if accidentally infecting them with Alien Mushrooms makes him sad, then he's going to have to accept their limitations and take whatever level of interaction he can get. If text chat and playing Pong with a human isn't enough to make him happy, he might want to look for some other species to play with. [Answer] **He could try playing with a young kid.** Children, because they have not experienced as much as adults, often lack the same level of understanding of events that adults have. So they are much less likely to go mad and die simply because they don't really understand that this is an eldritch abomination. I've also found that young children tend to enjoy playing, especially having dogs go fetch, so Jimmy could try to look sort of similar to a dog and that might help, too. [Answer] The key to peaceful communication lies in [Creeping Normality](https://en.wikipedia.org/wiki/Creeping_normality). Jimmy likely has plenty of time to work on establishing the connection, as most Eldritch Abominations are quite long-lived, if not immortal. Jimmy needs to make contact gradually, over generations. Choose a family that seems to be pretty hardy and with a bit of natural insanity, and make some very minor contact - just enough to make them comfortable with the idea of there being *something* more. After a generation, when the children are now being raised with knowledge of there being *something*, now push just that little bit further, and perhaps expose them to a few relatively mundane words in Eldritch. Given the power of the Eldritch language, perhaps restrict it to something that will have some minor effect, but nothing literally mind-blowing. Maybe a word that causes the lights in the area to dim slightly as it's said. The next generation might then experience the first telepathic contact. Just a moment's contact, not enough for them to be driven mad, just that flash of contact enough to give a seed of questioning of reality. By this point, the family is probably going to become a lot more insular as neighbours are probably going to think them mad. By this point, you've probably got something not unlike the Addams Family - they're all a bit twisted in the head, and the Eldritch touch has probably also warped them a little, physically. In a few more generations, after having given a few more words and exposed them to just a little more basic contact, it's time to make things just a little more personal. Telepathic communication while they sleep. This is the test for suitability - Jimmy should be able to test their minds during sleep for whether they'll be able to handle more. So Jimmy appears in their dream via telepathy, just forming a presence. Those who are unsuitable will rapidly develop insomnia, and Jimmy can either pull back and leave them be, or just have a little Eldritch fun with them, depending on whether he's feeling malevolent at the time. Those who don't develop insomnia are the ones to keep an eye on. These are the ones that are hardy enough in mind to potentially accept further contact. By this point, they should have enough Eldritch to be capable of the most elementary of communication. Jimmy should start teaching a few more Eldritch words within their dreams. Make sure not to choose powerful words that might be usable to create portals, etc - they're not ready for that. A few more generations in, and Jimmy should be up to the point of always being present in their dreams from a young age. They are probably also physically warped enough that local villagers think of them as monsters, and just mad enough to be worthy of the word, without being truly insane. Once this has been achieved, Jimmy can get a little more forceful - apparitions, momentary glimpses into Eldritch Space, even perhaps a few words capable of opening a flimsy portal (just enough that they can get glimpses at will and perhaps be slightly exposed to Nether Realm, without getting close to making a proper gateway). It's at this point that education becomes critical - they're ready to learn of the dangers of the portals and how to defend themselves using Eldritch words and techniques. After a couple more generations, they should be ready. It's time for Jimmy to reveal some of his true form. A few will probably go mad and kill themselves, anyway, but the hardier ones should withstand the big reveal. These are the ones that Jimmy will be able to start playing with... albeit only slightly. A few more generations, and Jimmy will have a family of near-human beings that have just enough Eldritch in them to play ball with. [Answer] Jimmy should stop communicating with *normal* (sane) humans and focus his attention to those who are already considered insane by the society. He should contact one such insane person through telepathy and invite him to play with him. The insanity of his human friend would keep him from the dangers of horror which Jimmy emanates and one day, someone insane enough will respond to him and agree to play with him :) [Answer] Jimmy creates a fountain of youth and immortality. Then Jimmy tells one of the humans about it. That human probably goes mad and dies, but not until he tells other humans. These humans try and seek out the fountain. When they drink from it, Jimmy gets to play with them forever. They'll go mad, but they will never die. EDIT: Make sure to dispose of insane immortals in a black hole when you are done with them. Leaving them on the planet can spoil the whole thing. [Answer] Jimmy realised that it's really only the meaty parts of his playmates that tend to go rancid when he's around. If he could somehow separate the meaty parts from the other parts, everything would be alright! Luckily his potential friends separate from their meaty parts quite easily. Blunt force, trauma, electric shock, flensing. They pop apart quite easily really. Once the meaty bits are separated Jimmy can bring out the red ball and play catch all day. Jimmy hasn't quite figured out how to put his playmates back how he found them though, so when Mommy calls him to come home and feast on the corrupted dreams of heroes and prophets, he leaves behind a bit of a mess. Maybe tomorrow he can play the game where he tries to put one back together! [Answer] Jimmy should play with the scientist who just invented a tool to erase recent memories (we'll call him Fred.) Fred is so horrified by playing with Jimmy that he cannot help but erase his memory of the day. The trick is to make sure that Fred doesn't realize how long he's been playing; if he thought he'd already erased his memory of these unspeakable horrors thousands of times, he might decide to stop playing altogether. This means Jimmy has to do a bit of work to keep Fred's environment in order, so as each day starts, nothing is apparently wrong. Jimmy will probably get bored of this eventually, leaving Fred to discover the true depths of his nightmare, but I'm sure by that point there will be a New Toy to play with. [Answer] I have a dog. She has a red ball All she wants to do is get a human to play with her and the red ball. Okay, my dog is unlikely to drive anyone to the point of going mad and dying. Jimmy might be able to take a hint from my dog though. He could endeavor to appear as a lovable pooch and he could bring his ball. Jimmy would have to take care not to reveal tentacles and the like so there might be a period of trial and error with requisite gibbering, but if Jimmy is careful, widespread madness and casualties could be reduced. Jimmy could also time his appearance with, say, Burning Man, so that the appearance of a friendly dog would go unnoticed and oddities like tentacles and the ball not behaving strictly in accordance with local physics could be rationalized by humans as a side effect of any recreational substances passing around. If jimmy got picked up and taken home, I don't give great odds on that person maintaining sanity, but at least the people who hang out at Burning Man are generally mellow, so we could hope that bloodshed is minimal. As far as communication, have you ever had a dog? I swear I can have lengthy conversations with my dog that make more sense than conversations with my friends. It doesn't need telepathy, just a little empathy and patience. Granted, it's risky when dealing with a creature from the beyond, but Jimmy might find it worthwhile. After all, Dogs can communicate the desire to play ball with very little problems. Jimmy! Fetch! [Answer] # Animal proxies Either possess or telepathically communicate with a cat, and then use the cat as a proxy for playing with the red ball and humans. Assuming that the Jimmy can survive the purified essence of evil that composes the inner workings of a cat, the cat's cute exterior should protect humans from interacting with Jimmy. In fact, this may already be happening... [Answer] 1. Horror needs to conceive a child with a human. As exemplified by Wilbur Whateley in The Dunwich Horror this can go fairly well for all involved. Including, surprisingly enough, the mother. 2. Raise child to adulthood. Eldrich parent may be involved to greater or lesser degree. Said child will be horror enough to commune with horrible parent but human enough to commune with humans. It is possible that child might be too horrible to commune with humans (e.g. Wilbur's sibling) and so this might take more than one try. 3. Child can play ball or mediate ball game or arrange eradication of all earthly life according to interests of parent (and child). [![from Deities and Demigods, 1st edition](https://i.stack.imgur.com/5e6b2.jpg)](https://i.stack.imgur.com/5e6b2.jpg) Image from Deities and Demigods 1st edition [Answer] # Anterograde Amnesia Jimmy finds a human / causes a human to have [Anterograde Amnesia](https://en.wikipedia.org/wiki/Anterograde_amnesia). This causes the human to be unable to make new long term memories. The human will not remember what happened the previous day. There are cases where people can only remember the last five minutes, and some where they can remember what happened that day, but forget that day over night. As shown in the famous [Henry Molaison](https://en.wikipedia.org/wiki/Henry_Molaison) case, Henry was still able to learn new skills, so if they play eldritch ball together, Henry will get better at playing, but will need to learn/review the rules every day. Maybe the human will subconsciously become more comfortable with Jimmy over time. The [wikipedia article on Anterograde Amnesia](https://en.wikipedia.org/wiki/Anterograde_amnesia) goes into more depth and has more notable cases worth reading for more uses of Anterograde amnesia in this scenario. [Answer] Sad, but determined Jimmy oozes over the alternative fabric of reality. *There must be a way to be happy, to have someone to play with*. So Jimmy simply opened his telepathic sense and listened very carefully, being very, very still. With practice Jimmy was able to listen after some unfortunate accidents of people going mad and committing suicide, the humans only had some nightmares. Jimmy finally understood and thought he/she/it has found the solution. A few days later, in the scanning room of the Secret Service. > > Mr Smith: What the hell is in **this envelope**?! It smells...strange. > > Mr Jones: No detection of chemical weapons or explosives. (Opens carefully). It's a letter. > > > *Dear Mr. President,* *my name is Jimmy. At least this is not my real name, but it is very hard to spell out for your species.* *I want to have some playmates who are playing with me and my red ball. Unfortunately your species is quite fragile in my presence. You have very much power, so I thought to contact you because I am confident you will find me some nice playmates.* *If you do not respond in one week, I am coming for you (Sorry for this inconvenience, but experience of your species tells me it is necessary to add this to initiate an immediate response). You find me at a location named Dunwich, Miskatonic River, Massachusetts, 10 miles north of the city center in an old barn.* *Yours, Jimmy.* > > Mr. Jones: Those weirdos are getting better and better (laughs). > > Mr. Smith: (chuckles). Yeah. Erm...(silence)...why is your arm turning blue? > > Mr. Jones: My ARRRMMMMM! AAAAAAARGHHH. > > > **NCC Live News. We are the eye of the world**. "Hello, my name is Rebecca Porter. I am here in the town of Dunwich in Massachusetts where a terrible tragedy has happened. I am talking to 4th star general Rupert Grant. General, what did happen?" "(Looking really unhappy) Erm, we had an unfortunate....accident." "An...accident. General, our sources indicate that a convoy of 6 black cars passed the city center at 10:00 AM and headed north. A radio amateur heard someone screaming, turning randomly encryption on and off and crying for backup. 30 minutes later over 40 blackhawk helicopters appeared, heading for the same location. Two hours later a complete army division turned up, fully equipped with combat helicopters and battle tanks, some of the tanks modified with flamethrowers. **What is going on?"** "Please excuse me. I have a *very important* meeting right now." *Dear Mr. President,* *I am sorry if I was a bit messy, but it was really funny. All those things were quite tickling. It was very exciting to watch your reaction to all this news in your control room.* *I see that you seem to search useless solutions. You cannot hide. I have visited this strange location where you store all those yellow metal and this location where all those bumpy things are stored and placed some things from both places in your bunker you think nobody knows of.* *You also thought of those weapons you think are powerful. My comrades really like destruction, so I asked them to remove this strange planet/non-planet thingy from the edge of your solar system your astronomers are so proud of. Sorry if this was naughty* *I was surprised that you are not all-mighty, other persons have also power. You can tell them I come for them if you fail me, too. I am sorry that your general poked himself into his eyes, I was invading his mind and cleared accidentally my....eating holes?* *Yours, Jimmy.* **NCC Live News. We are the eye of the world**. In an unexpected move every state of the USA reintroduced the death sentence and speeded up the process. Rumors have it that every expert on science and engineering have been invited to the White House in an extraordinary meeting. Lawyer: Hello Mike! Mike: Mmmm. Lawyer: I know you will be killed tomorrow, but I was informed there is an option. Mike: [questioning look]. Lawyer put a red ball on the table. Mike: What? What solution was finally found was unimportant: The automatic robot shielding the senses of the human steering it, the human guinea pigs trying to play with Jimmy as good as possible (drugged, hypnotized etc. etc.), finding other amusing games, the US goverment did everything they could think of to make Jimmy happy. **And Jimmy was happy.** [Answer] Jimmy could communicate in Morse code. Naturally this would require that an Eldritch Monstrosity could understand such a human concept, but usually such creatures are known for driving humans mad -- not the other way around. So, all Jimmy needs to do is create a series of tall and short statues, depicting *Ichthala the All-Devouring Mother* (or as he calls her, *Mom*) and her dread offspring. Sure, most humans would see them, investigate, and go mad -- but once the raging cultists have been put down, someone would have the bright idea of finding a code in the statues. (Though they might be confused by the message, "Come play ball with Jimmy.") [Answer] Jimmy could inhabit horror movies, or "haunted houses" in fairs and theme parks, or present himself as a Bowie-like performer, or appear in some other place where he and his ball will largely be considered fictional. Alternatively Jimmy could only speak metaphorically, in parables, koans and myths as religions generally do. Jimmy could temper his message with great personal suffering so that others do not attempt to emulate him too closely, by nailing himself to a piece of wood, or (intentionally or not) going stark raving mad in his later years. Jimmy could remain silent about the more horrific elements of his nature, and perhaps hide his ball till later. Jimmy could say deliberately absurd things so as to make himself less plausible. Jimmy could speak to people like a post-structuralists in obfuscating and deliberately difficult to understand prose so that the realization of his horrificness should arise slowly only to those prepared to put a lot of effort into understanding him. Notwithstanding A4android's point which is valid to a degree, I think that there is future in YouStay Igo's answer, to attempt to approach the insane, or perhaps those from other disparate, non-rational cultures. Or Jimmy could try to find other Jimmies, who appear to be doing the things mentioned above, or to find those that have been exposed to Jimmies and not gone permanently insane, possibly by posting questions to stack exchange austensibly about how to create a fiction. [Answer] Jimmy should try some camouflage, so the silly humans won't recognize him as a horror. He could try covering himself with the outer covering of a human, aka their skin. Another popular tack is to breed a race of eldritch horror/human hybrids, in exchange for immortality, who aren't so bothered by his unspeakableness. They would be happy to play with him. Or Jimmy could skip the part about driving people mad and find some people who are already crazy, someplace nice like a mental hospital in an isolated place should serve nicely. [Answer] ## By using the universal language of Love "*You look kinda down, Jimmy.*" He (it?) immediately recognized the guttural voice. "*Oh, hi [Pappy](https://en.wikipedia.org/wiki/Azathoth). It's just that... oh, nevermind.*" "*Let me guess: You want to play with the mortal inhabitants of Earth. Am I right?*" "*Well, yeah.*" He (it?) looked gloomily towards the ball, and gave it a push with the tentacle closest to it. "*I see,*" said the voice, approaching the youngling. "*Well, I'll teach you a trick I taught [your cousin](https://en.wikipedia.org/wiki/Cthulhu) a long time ago. He wanted exactly the same thing - can you imagine? He may look all busy and important, but deep down he just wanted to be loved and have someone to play with him as well.*" That piqued the young Eldritch Monstrosity's attention. Pappy smiled(?). "*You see, the trick is to understand them. Like delicate toys, you need to care for them.* *They're skittish, so don't show yourself at first. They're curious beings, though: leave clues, and tell them about yourself at a gentle pace. That will get a few of them acquainted to you - some can't, but some will. And they'll come to you, wanting to play with you. Reward those, so others can see their happiness and desire to join the fun. They're fragile, and may catch a mind-disease or two, so make sure you inoculate them against most mind-germs.* *Do these things, and I'm sure you'll have a bunch of new mortal friends to play ball with in no time.*" Jimmy looked pensive for a while, but then his appendages erected in excitement. "*Wow, Pappy, I think you are right! I'll try that, thanks!*" Pappy observed satisfied as Jimmy teared space and time itself, rushing with new purpose. He truly loved his great-great-grandson. [Answer] Assuming that Jimmy has no means of direct communication to humans without killing them (barring writing, which is clearly too dangerous), he must instead find an effective medium of communication. Something that both he and humans are capable of understanding. For instance, humans have been trying to think of effective forms of communication with extraterrestrials for quite some time now. In fact, there are more human eyes and ears focused on the universe than ever, looking for any signs of life or communication. One thing that is often considered is mathematics. Many believe that mathematics comprise the rules of the universe, and therefore an intelligent civilization must live by those rules. Perhaps, since Jimmy is so powerful, he would have the means to create some mathematical, or even interstellar phenomena (creating/destroying things, radio waves, etc.) that, when manipulated correctly, would alert humans to an intelligent force in the universe. From that point humans could set up some form of zero contact communication. How exactly that early communication evolves into the ability for Jimmy to ask a human to play ball would be up to you. This is simply a way for communication to start safely. Another answer that does not involve the death of humans is this: Jimmy uses a nearby intelligent race in the galaxy, hopefully one that can resist madness longer than humans, to communicate with humans in a way that does not make their minds implode. This is also assuming that Jimmy cannot communicate through human languages, or he would have simply passed a note that said "Hey, wanna play ball?" [Answer] **Nerve Stapling** Many other answers assume Jimmy tries to limit itself to 21st century technologies and ethics. However, eldritch horrors have little need or want to limit their behaviour this way. For eldritch horrors Death is just that dude who lives down the hall, and even the 22nd century envisioned by Sid Meier's "Alpha Century" provides a more direct solution for undesirable behaviour. --- As Chairman Sheng-ji Yang says, Life is simply a collection of chemicals. If Life does not please you, simply edit those chemicals until it does. Insane behaviours such as starting murder cults and begging Jimmy for nap time can be edited out after the humans have been improved by the addition of Nerve Staples. Death sees the fun the humans are having and shows up and wants to play with all the humans. That is a bit greedy of Death, but Jimmy likes Death anyway and has good fun playing with Death. Alas, Death is not Life and has no nerves to staple. After the first few timeless aeons of play, Death goes a little funny and Death itself chooses to die rather than play with Jimmy anymore. Jimmy is a little sad at Death's Death, but now can play with the humans for multiple infinities of time, or until Jimmy gets bored and looks for other playthings. Jimmy is glad he doesn't have to worry about humans dying from little things like limbs rotting off, or new tentacles growing through internal organs. With only one death, this results in a lot less deaths than if Jimmy had let the silly humans waste valuable playtime eating, sleeping and dying. [Answer] Being a higher order of being, Jimmy the Abomination has an important advantage over the creatures he is interested in: He exists in more dimensions than they are capable of perceiving without outside help. All Jimmy really has to do is orient himself so that only a small part of his multidimensional form intersects the 3D habitat of his playmate. He will likely not appear truly human, but with enough practice he can surely find a form to present that is nonthreatening enough for mere humans to tolerate. Of course, Jimmy has to be cautious of how he interacts physically with his playmate, lest he accidentally jaunt the poor soul along an unfamiliar axis and expose him to the true shape of the universe. [Answer] Oldie, but a goodie... **Intermediaries** The trouble with eldritch abominations is that if their very form is capable of driving a human irrevocably insane, I'm not sure anything humans could construct would be capable of handling Jimmy either, and testing the boundaries for how much Jimmy they can handle would likely cause casualties. I'd strongly expect a computer to freeze or melt or start infecting humans. I wouldn't be surprised if we'd get a similar reaction when Jimmy meets the laws of physics. This could pose a problem with the longevity of his playmates. So, what Jimmy needs is to create an intermediary being that is *slightly* less eldritch than it is. Still eldritch enough that it doesn't melt when Jimmy speaks to it, but a little step on the way to being human. Step1 then creates another being, *slightly* less eldritch than it (lets call it Step2), and so on and so forth until you have something that is actually capable of communicating successfully with a human. Then, Jimmy can get its intermediaries to take his red ball, modify it slightly so it's slightly less reality breaking at each step and pass it down the line along with a note that will eventually translate to *'If you are human, please take this ball, perform these modifications and pass it back to Christopher Walken. Do not interrupt what he does next.'*. And hey presto! Jimmy's playing both Catch and Chinese Whispers, with (hopefully) zero casualties! I would advise against progressing to Musical Chairs though... [Answer] Become a real estate developer. Since they expect you to be a monster, they'll just see you for what you are. If that doesn't do it, become a reality-TV host. I have one more suggestion but I'm reluctant to say it. It still won't win you over everyone, but half. Well, maybe a few million shy of half. But who's counting? [Answer] ## Physics. Jimmy tried to communicate with a physicist, and found himself the owner of a dozen books with crunchy trabeculae of spongy bone decoratively embedded in the pages. After much, much torment that could leave even an eldritch horror in a state of misery and confusion, Jimmy finally had done it: he *understood* electrostatics, electromagnetics, loop integrals, eigenvalues, even a little quantum mechanics though I'm not sure Cthulhu Itself has quite gotten that one down yet. Now Jimmy posts his lectures to the internet and nobody goes mad, because nobody understands him. Even if he turns the video on, they just look in glazed-eye confusion and back at their notes again, before planning a second visit to the registrar's office. [Answer] # They're in the Matrix As Jimmy is ruminating after the death of his latest potential human friend and thinking "Why?! Why me? Why must I have such bad luck? Will I always be lonely?", he realizes the obvious truth--he's in a simulation. We're all in a simulation. And he comes up with a plan to get back at the cruel Creators of the simulation, so lacking in empathy that they refuse to give him a companion to play with. With a little digging, Jimmy pieces together the details of how he came to be: our Creators made several simulations of widely varying worlds, and the worlds of mortals and Eldritch monstrosities are two of them. Now, an intern wrote some sloppy code allowing memory to leak out of the Void and into the mortal plane (yes, I know this isn't how memory leaks work, just humor me). This is what allows Jimmy and his friends to come greet us. Unfortunately, because Lovecraftian horrors have a different layout and size from objects from our world, they tend to corrupt the chunks of memory they are placed in when they visit us. This is what keeps causing teensy tiny glitches in the Matrix. Now, Jimmy doesn't have the processing power or access available to him to modify the way the simulation works to allow him to seamlessly play with humans without damaging them. However, the Creators do, and he decides to send them a message. I'm not creative enough to think of what that would be, but think making the Sun implode or something. He lets the Creators know he'll keep doing this unless they give him a human companion to play with (these entities have tools to understand all the entities in all their worlds). If his demands are met, he'll persuade his fellow abominations to leave the humans alone and spread chaos in their own world. Win-win! Of course, the Creators can delete him, but it will take a long time for them to hunt down where Jimmy is, given that he's a memory leak. In that time, he could wreak untold havoc, and they certainly don't want to waste their time piecing one of their precious worlds back together. Going along with him would help them keep our world safe while they fix the vulnerability allowing Jimmy's friends unrestricted access to our plane (don't worry, they'll let Jimmy and some select monstrosities through the Gateway to do research on "interdimensional interspecies interaction"). So, how can a Horror from Beyond Reason reliably communicate with mortals? Coercion, I guess. ]
[Question] [ I just got shoved through a stargate onto a planet I don't know. I was told the gate would open again in exactly one Earth year. I wasn't carrying anything; I don't even have my watch. How do I know what day I can return home? I can count days, but first, I need to determine the absolute length of this planet's day. How can I do that? I can't just count off seconds - way too inaccurate over a period of hours. I could make a pendulum to use as a clock, but that's useless unless I know the value of gravity here. I don't know the air pressure or % oxygen, just that I'm able to breathe. *The scenario should be recognized as contrived and not picked over. I recognize that it probably wouldn't be worthwhile to actually try to measure time in this situation. The point is, **how accurately** can you measure time without a reference?* *I asked this because I was wondering if there was any physical process (other than nuclear decay) with a rate that was independent of (or at least highly insensitive to) gravity and pressure, and not requiring an accurate measure of mass.* [Answer] Use a stick to create a sundial. Now start counting your heartbeats. Very roughly you can expect ~5,000 per hour (80 BPM). Make marks where the shadows lie every ~2500 beats or so. Make sure you're in a resting state when you take the measurements. Do this over and over on several days and you should be able to start making a good estimate of the planet's day length and seasonal cycles, with a value defined by your resting heart rate. Now you need to estimate what your heart rate is compared to earth time. Don't go for an exact value, like 83 or 65. Instead try for a range. Maybe you're pretty sure your heart rate is between 74 and 89 BPM. Take your day data, combine it with your estimates, and that will give you a lower and upper bound on the number of days before the portal will re-appear. Now use the time before your lower bound to prepare - gather food and water, create shelter, see if you can set up some sort of alarm, etc. Then wait and hope. [Answer] Are you female? And if so, how regular is your period? A healthy female in prime child-bearing years will cycle on 29.5 days. Even women that cycle longer or shorter will usually cycle a set number of days. So, that could get you at least to a range of days to hang around the stargate. Now, that said, stress and diet (starvation) will affect the cycle -- it can shut it off; which, knowing that can add some nice tension to the story. So you could also use your cycle early on to calibrate how long a local day is. And there's the potential worry that light affects the female cycle. The moon also cycles 29.5 days, and a woman's cycle (potentially) synchronizes to it (maybe). It's not very well understood at this point. But, I'm sure that'll haunt you out there on that planet... :D :D :D [Answer] **Use John Philip Sousa...** (I like "Stars & Stripes Forever" personally, but do ignore the *rallentando* going into the third repeat of the first strain!) If you've any exposure to him you can probably hit 120 beats per minute to within +/- 10; if you've any musical training that's closer to +/-2 bpm. Let's assume +/- 6bpm, because I don't know you. That's an error of one part in twenty. **...to calibrate a pendulum's length...** Holding the top with one hand, occasionally giving it a kick at the bottom of its swing to keep it going—pushing it at the bottom will perturb its timing the least. Once you've got the length marked out of a 120bpm pendulum, go ahead and rest your arms a moment while gathering material for the next part. This solves your problem of not knowing the local acceleration due to gravity. (Which we hope is constant to better than 5% over a span of hours. If not, you've got bigger problems.) **...to calibrate a sundial.** Quadruple the length of your pendulum—doubling its period—and hang it from some improvised frame. Within seated arm's reach of your new grandfather clock erect your gnomon, mark your starting point, and start your grandfather clock. (Remember to give it its kick at the bottom—not like pushing kids on the swing.) Make a tick somewhere every 60 (or 100, if you're ambitious) ~seconds~ and after 60 (or 36) ticks mark the end of the hour at the shadow's tip. And do it again. And again. (Counting this many beats is do-able, but it takes discipline. Again, you'll be in good shape if you've some musical training. Particularly if you've been a brass player in an orchestra--plenty of hundred-plus measure rests in that repertoire!1) **Now build yourself a bevel gauge:** mark out eight times your three-hour count. There's your Earth-day. Now in 346 of those go to your gate location prepared for, at most, a nineteen-day wait. (That is, assume your one-part-in-twenty error was in the direction of counting too slow: you want to show up 1/20 \*365 days "early" so that even your slowest count gets you there a good half-day before your gate opens.) **This won't work if...** * *Local gravity varies* by more than a few percent over a few-hour span. By itself, I don't think that would wreak too much havoc on you, biologically. I'm guessing you could survive elevator-like levels of gravitational variance2 for a year. But I'd be seriously worried about whatever's *causing* that level of variation. Nearby orbiting attractor? Probably no atmosphere, then. Your system orbits an infalling pair of black holes? Good luck surviving the irradiation. &c. * *There's not enough light* to use a sundial. For long periods. If it's overcast for a few presumed-days before you can do this work, not a problem: pad the wait-window by those few days. But if we're talking many many weeks of no appreciable visible light, then will this biome support your food needs for a year? * *The planet rotates slowly* enough that you can't perceive the shadow's motion in mere hours. In this case you've got temperature differentials on the light and dark sides of the planet that are going to cause killer (literally!) weather. Not just a problem for you but, again, for your support biome. I don't doubt things could live in perpetual 200 mph winds, I just doubt you could digest them! **It's better than the non-answer "it can't be done"** because now you're not tied to an area within (gate open-time)$\times$(running speed) of the gate location. **It's better than heartrate** because that can be soooo variable. As a runner I know that my resting rate may be as low as the 40s, but on a stressful (Earth) day my resting rate might be nearing 60. +/- one part in five is no good. Even at the bad end of the tempo-range you'd be hitting one part in twelve. **It's better than sleep cycles** because we're actually diphasic sleepers: in darkness we can easily sleep three or four hours then come wide awake, feeling refreshed as after a full night's sleep, only to re-tire an hour or two later. That's in our preferred environment, when well-fed. Throw hunger, stress, and unnatural stimuli into it and I don't think you're going to get one part in twenty accuracy. --- 1 - Much rarer, but better-equipped for this particular exercise, are [change ringers](https://en.wikipedia.org/wiki/Change_ringing). They'll stand upright for nigh-four hours one morning, pulling rhythmically and counting their way through the 5040 permutations of their band's bells; have lunch; and do it all again in a different order in the afternoon! 2 - I know gravity's variance isn't what you're feeling in an elevator. But I'm hard-pressed to find any other description of what it'd *feel like* living in an area where local acceleration due to gravity varies by a few percent within hours. Suggestions welcome. [Answer] There is a bit of confusion about my answer. I'm updating the answer with clarifications and additional information. The quotes are my original answer. **TL;DR** > > I think the best answer is: you can't. > > > You can't realistically get close to 24-hour accuracy with any method mentioned. The only methods that close require atypical knowledge and very specific circumstances. More realistically, you're probably looking at an error window of 30-60 days. Try to stock up and stay as close to the gate as possible for those last couple months. **Assumptions** The question specifically asks how a person could know what day to return. My assumption is this is an Earth day, and I'm going to be generous and assume $\pm$24 hours is acceptable. Said another way, we're looking for accurate enough timing that you could walk away from the stargate for 364 days, then come back and be confident that you're not late, and no more than 24 hours early. (Note the question was edited so it's no longer so specific. The revised information tries to calculate the realistic accuracy and why this was my answer to begin with.) We know the planet has breathable air, but nothing else. For all we know, you're literally the only living thing on the planet. But since there's a presumption that survival is possible, I'm going to assume this planet is fairly Earth-like, is populated by plants and animals similar to Earth-life (particularly, they're made of proteins, vitamins, etc. that are digestible by humans), and that the environment near the stargate is similar to some environment here on Earth. The question asks about a "stargate", so I'm going with a Stargate approach: a few million years ago, some ancient almost-humans explored the galaxy, constructed stargates on thousands of planets, and terraformed quite a few of them. In that time, other aliens have moved in, invaded, crash-landed, etc., and natural evolution has occurred as well. The planet is similar to Earth, but may have marked differences from Earth. The question specifies that "I" got stuck on the alien planet. I don't know much of anything about the writer, so I'm going with a statistical approach. The writer obviously has access to a computer and the internet, so I'm assuming we're looking at a statistically-normal first-world citizen who is probably reasonably smart, understands at least the basics of core subjects at about a high school level, and to make the answer interesting, I'm assuming this person has a strong desire to live. Clearly, some of the suggestions below would fail if the planet were less Earth-like. For example, if it's tidally locked to the local star and the star is too bright to see any other celestial objects, sundials and the like wouldn't work. That just makes my answer more right, so it's not really important here. > > Most of the suggestions here would get you in the ballpark, but none of them would be highly accurate. Circadian rhythms, menstrual cycles, resting heart-rates, etc., are all based on many factors. First, none of those are the same from person to person, so you'd have to know your own. Second, they're all affected by stress, metabolic rates, nutrition, and so forth, so the instant you hit the new planet they change. Third, none of them are going to be the same from day to day or month to month with extreme accuracy even in a modern, normal, predictable life, much less on an alien planet. > > > Before we begin, note that there are two separate parts to this answer. The first part is counting time on the new planet. The second part is determining the ratio of local time to Earth time. **Local Time Keeping** > > Very few people would have the knowledge or skillset to build a pendulum clock or anything more complex, so you'd basically be restricted to sticks and shadows, which would be accurate to a few minutes, but not much more. And unless the planet is in a perfectly circular orbit with zero axial tilt, the scale of your clock will change every day. So you'd need a local year or two to really calibrate the clock. > > > First, let's look at suggestions for determining local time. It's pretty easy by comparison. 1. **Count the Days**. The easiest counting method is alien days. You've got a giant alien clock right under your feet. Just tick off how many days have passed, apply a conversion factor, and voila! You could also use a readily-identifiable constellation, a moon, whatever. (Technically, distant stars are best, because highly-eccentric orbits don't affect that measurement.) 2. **Use a Sundial**. But you need to correlate alien days to Earth days. It's unlikely you can maintain any particular counting method for the entire day (moreso to do so without errors), so you'll want a shorter interval. A sundial will give you a good way to track time in hour-ish increments, and possibly as good as minute-ish increments. Sundials are extremely easy to implement, so that's good. Use one of the Earth-time methods below to see how long 5 alien minutes, or one alien hour, etc. are. The bad part of a sundial is that the ratio (probably) changes from day to day, so you'll have to take that into account. It's best if you can get the timing of an entire day/night cycle, so you'll want a "stardial" of some type. Using a raised, flat rock with sand on top, you can put a pointy rock near the edge, then sight along it from below and beside the flat rock. Put a mark in the sand directly between your eye and the rock, while "aiming" the end of the rock at some notable star as it comes off the horizon, then another mark every so often (every thousand heartbeats, or every tenth time you finish Mary Had a Little Lamb, whatever). Make another mark when the star goes behind the horizon. By comparing the arc length of several smaller intervals to the arc length of the full night, you can estimate the length of the night. Unfortunately, neither of these is going to be terribly accurate. You either need to build a really big sun/stardial (this is possible, and probably a good idea), or make very precise, very tiny marks each time. Otherwise each mark will span minutes, perhaps tens of minutes. 3. **Build a Pendulum**. A really nice way to tell shorter time periods is some type of periodic motion. Like a pendulum. Unfortunately, keeping the pendulum swinging is a rather large feat of engineering unless you want to push it manually, in which case you'll introduce more error. Still, this is probably a pretty decent approximation given your options. But you need to make sure to use a thin, light string of some sort, or get some really slick goop to "oil" the contact if you slide, e.g., a stick onto another stick with a hole. Otherwise the stiffness or friction is going to introduce errors that will be hard to account for later. For most people, the pendulum will be adequate for measuring time over several hours to more accurately calibrate the day, but it's unlikely many people could construct an actual clock any time soon. 4. **A Water Clock**. This requires you to be capable of moving water in sufficient quantities to fill at least one bucket, and preferably several, and is a pretty decent way to estimate the length of a day. You wouldn't want to keep it running constantly, but you don't really need to so that's fine. 5. **Find a Local Clock**. It's possible there is an existing civilization who has existing clocks. This makes your job trivial, but isn't remotely guaranteed. Plus, they aren't guaranteed to be friendly if they do exist. I think there are probably some other methods I missed which would work decently. All of them will have some margin of error, but it's plausible they would be good enough. The worst problem here is that you don't have very long to build an accurate device. If you spend 6 months constructing an elaborate grandfather clock, any physiological processes you might have used to calibrate the clock will have long since changed. **Relating Local Time to Earth Time** > > If you could engineer stuff, and you happened to have an object of known mass, one of known length, and one with a known spring rate, you could use all of that to determine the local gravity and make a clock from there. But you'd have to remember of bunch of physics equations off the top of your head and be able to apply them with rudimentary technology. All while not getting eaten by a Grue. > > > There are probably ways to make chemical clocks, but I doubt a layperson could do it at all, and even a chemist would have trouble without a lab on the planet. The speed of sound and electricity are variable depending on the medium, so wouldn't work very well. The speed of light is pretty constant through air, but you'd really need to know either time or distance for it to help. And good luck building a device to measure any of the above out of sticks and stones. > > > So now we need to get the Earth duration of some unit of alien time. This is where it gets extremely difficult. I'm going to cover the major ideas presented on the page so far, and why none of them are particularly great. I'll also try to give reasonable estimates of how accurate they are. Naturally, these don't cover every single variation of answer, but the same premises will apply to similar answers. 1. **Count Your Heartbeats**. My resting heart-rate, as measured by professional nurses with actual medical equipment, while I'm as calm and rested as I can get, has ranged from ~70 to ~110 BPM. It tends to be in the 80-90 range. I don't know what a typical deviation is for a single person, but it's probably at least $\pm$5 bpm. So 85 $\pm$ 5 is an error of $\pm$ 5.9%. After a year (I'm using [365.2422 days](https://en.wikipedia.org/wiki/Tropical_year), although I doubt the extra precision matters here), that 's a $\pm$ 21.5 day deviation. That assumes the person going through knows their own average resting heart-rate. It also doesn't take into account the incredibly significant effects of stress (you just got tossed through a stargate and have to survive here for a year), the alien environment (different gravity, oxygen levels, air pressure, etc. will have an effect on your biology), or, as days and weeks pass, the different nutrition you'll be getting, your physical condition, etc. Realistically, most people probably won't be able to be certain of an error margin of anywhere near the $\pm$ 5 BPM range, driving the deviation even higher. 2. **Measure Your Period**. It's quite typical in normal, everyday Earth life for a woman's period to be off from average by $\pm$ 2 days or more. Average period length is around 28 days, which gives an error range of $\pm$ 7.1% or $\pm$ 26.1 days. [Wikipedia](https://en.wikipedia.org/wiki/Menstrual_cycle) puts $\pm$ 4 days as more typical, which is an error range of $\pm$ 14.3% or 52.2 days. The highest typical period length is around 45 days for adolescents, or 31 days for adults. 45 days $\pm$ 2 days gives an error of $\pm$ 4.4% or $\pm$ 16.2 days, while 31 days $\pm$ 2 days is $\pm$ 6.5% or 23.6 days. Like heart-rate, period length will be greatly affected by stress, diet, etc. It's actually a bigger issue here, because the next period will be days to weeks away, meaning your body will have a lot of time to adjust to the new conditions, while the heart-rate measurement could be taken within minutes of arrival. And, period length is usuable to less than half the population. About 50% of the planet is male, and while I didn't bother looking up numbers, young girls and older women don't menstruate, so actual numbers will be less than 50%. Another issue my room-mate mentioned is birth control. Anyone currently taking birth control will have substantial hormonal changes going on once they hit the new planet and have no more pills. 3. **Use Your Favorite Music**. Obviously, not everyone has heard of John Philip Sousa, let alone memorized any of his songs, but most people know a decent number of songs. Great! But does that help? Not really. I highly doubt the average person can tell you the BPM or running length of any particular song they own. I can guarantee that only a (relative) handful of people are capable of singing through an entire song without missing a beat. Then they have to get the exact right tempo. Certainly there are plenty of musical professionals who could do a pretty decent job. But even then I doubt they'd hit the 24-hour mark. That answer says 120 BPM $\pm$ 2-10 is reasonable for someone with moderate to little musical training. That's an error margin of $\pm$ 1.7% to 8.3%, or 6.1 to 30.4 days. Even the tight end of that scale misses the mark by quite a bit, but is looking good compared to other answers. I'm not a musical expert by any means, and had no luck looking up statistics relevant to this, so I can't comment on how accurate that $\pm$ 2 BPM estimate is. But something tells me that's after sitting in front of a metronome or similar device, and most people probably program that timing with a musical instrument. The lack of any such tools would probably throw the estimate off by more. Again, stress and local factors could have a huge impact on the perception of time and the ability to maintain a consistent rhythm, even for the pros. 4. **Measure Hair or Nail Growth**. To add to the idea, when I went through basic training the new toe nails were much thinner than my old nails, and I could visually see the time passing. Hair grows around [6 inches](https://en.wikipedia.org/wiki/Human_hair_growth) per year, while nails grow around [1.44 inches](https://en.wikipedia.org/wiki/Nail_%28anatomy%29#Growth) per year. It's probably a lot easier to measure hair than nails in this case, but it's easier to cut into nails to keep them marked in more precise intervals. And there's a big difference between the length of neatly-brushed hair and caveman hair. However, as Wikipedia points out, actual growth time can depend on many factors, such as the stress, etc. on our alien planet. More importantly, I highly doubt many people could tell you their personal growth rates right now with any significant accuracy. It's hard to put an estimate on the accuracy here, but it's probably at least $\pm$ 10%. Hair on different parts of your head doesn't grow at the exact same rate, so you'll have to average it out a bit. Not everyone will have *just* gotten a haircut when they got pushed through, so the unevenness will be even higher. Plus the biological factors. 5. **From freshman astronomy, you remember that the period of Delta Cephei (a cepheid variable) is 5.36 days, doubling its brightness at maximum**. This is a pretty good trick, but that requires the person to have learned this fact (or one like it) at some point, still remember it to an exact enough value, and be able to find the star in question. Given that stargates could dump you all over the galaxy (or even other galaxies), this is a very niche technique. If you can use the trick, the $\pm$ 0.01 day accuracy is good to about 2.4 seconds at the end of the year, although you'd likely be off by at least a few hours in trying to determine the center of the maxima and guessing at how long it had been between arrival and the first maximum. But certainly a very good technique. But if you can't use the trick, it's worthless, and the odds of the trick working are very slim. 6. **Practice a Speech or Clapping Your Hands**. This sounds like a neat idea on its surface, although I doubt it's terribly accurate. Remember that alien worlds could easily affect your speech and muscles by a considerable margin. But the worst problem is it requires preparation. If I was going to prepare, I would bring something with me that was far more accurate, like a watch. Even simple things like calibrated springs, weights and rulers would do a better job. If preparation is allowed, it becomes trivial to calculate time. But that's not what the question asked. 7. **Dial a Random Gate for 38 minutes**. I thought of this one, and it's not a bad idea. There are still problems. First, this narrows the assumption from "Stargate-like" to "this is the Stargate universe", which is probably too narrow. Second, most people probably never knew about the 38 minute limitation, let alone remember it. But more importantly, it took trained professionals (in-universe, which we need to consider meaningful if we're using the 38-minute rule) decades to get one correct address. The odds of successfully dialing out in the entire year you're there are vanishingly small. However, if it worked and you happened to get a gate open, $\pm$ 1 minute translates to about $\pm$ 2.6% accuracy or $\pm$ 9.6 days. So we've still missed our window, but it's not a bad estimate. 8. **Calculate the Period of a Pendulum**. For starters, your height is probably much less variable, and a longer length translates to better accuracy in the long run. So I'd use that rather than an erection. But can we actually do it? Not really. The formula for the pendulum makes several assumptions already, so we need to be careful. But let's pretend we can meet those assumptions using weeds and sticks and so forth. We still need to find both L and local g. L is easy enough with something like your own height. Pretty much everyone knows their own height, which is a huge plus, but it's not ridiculously accurate. Best case measuring accuracy is around half an inch, and most people are probably between 5' and 6.5' (60-78") tall. That gives us an error margin of $\pm$ 0.8% to 0.6%, which is quite good, leading to a $\pm$ 3.0 to 2.3 day total error. But we still need to be able to replicate that height on the alien planet, which is probably going to double our error margin to around $\pm$ 6.0 to 4.7 days. But we're not finished. We still haven't found local g. The proposed method won't work once you're on planet. It requires you to know the initial velocity of an object, which requires you to measure distance over time, and time is the things we're searching for. Two unknowns, one equation. If we happened to know how far and how fast we could throw a particular object on Earth (as suggested), it could work. But there are several variables to consider. According to [this random site](http://www.beyondtheboxscore.com/2014/8/20/6044553/do-hard-throwing-relievers-really-pitch-better), MLB pitchers (they're literally pros at throwing things) throw a baseball about 92.15 mph, $\pm$ 2.6 mph. That's $\pm$ 2.8% or 10.3 days of error. Then remember that most people aren't pros. And we're throwing random rocks or sticks that won't be the exact same mass and shape. Then there's throwing distance. I can't find any good references, but we're adding at least a few percent here. Finally, there's throwing angle. According to [Wikipedia](https://en.wikipedia.org/wiki/Strike_zone), MLB pitchers had an easy time hitting a strike zone between a batter's shoulders and knees. Let's call that a 4 foot height, which is at a distance of 60.5 feet from the pitcher. That's an angle of $\pm$ 1.9°. Using the $d = \frac{v \cos \theta}{g} \left( v \sin \theta + \sqrt{v^2 \sin^2 \theta + 2gy\_0} \right)$ given, with a velocity of 70 mph (we're not all MLB pitchers), $y\_0$ of 6 ft, Earth gravity, and a horizontal throw, we get distances between 52.8 and 74 feet. That's 63.4 $\pm$ 10.6 feet, giving an error margin of $\pm$ 16.7% or 61.1 days. Now, the errors given so far have been *per measurement*. We need to add them all together to get the final measurement. With a tall person (6.5'), that's a total error of $\pm$ 20.8% or 76.1 days. And, yet again, local factors will cause more deviation. (Of note, adding them together means you get a more condensed curve, so it's actually a little better when accounting for whatever arbitrary probability cutoff we're using. $\pm$ 15% or 54.8 days might be a better estimate.) 9. **Drop an Object Off a Cliff**. 10. **Measure Echo Distance**. These suffer the same problem that they require a precise, working clock to make your measurements, which negates the purpose of the experiment. 11. **Measure Time to Run a Distance**. The problem here is it assumes people can accurately determine a half-mile distance and know how fast they run it. But both of these assumptions are flawed. First, normal people don't do that much running to begin with, and can probably guess their half-mile speed to $\pm$ a minute or something. But anything substantially better than that isn't likely. Second, I've met *many* people who couldn't judge 100 yards within 20%, let alone 1700. This second problem can be somewhat overcome with time (use your height to measure a length of wood, then use that to measure half a mile to decent accuracy -- probably $\pm$ 2-5%). Additionally, even professional runners are unlikely to maintain close to their normal pace when you put them on a random alien planet on rough terrain. Even if they can easily tell they're slower than normal, they won't have any particularly reasonable way to determine how much slower they are. You're still going to be off by at least several percent, and probably 10-20% depending on just how rough the terrain is. This is another place where it's pretty hard to make any estimates, but probably a minimum of $\pm$ 10% or 36.5 days. 12. **Find an Atomic Clock on the Planet**. This would certainly be an excellent method of telling time, because it's the same frequency anywhere in the universe. However, you'd have to remember off the top of your head that Cesium oscillates at around 9.19 billion cycles per second, and hope the aliens are using Cesium, and that you know enough chemistry to verify that they're using Cesium (they aren't likely to call it Cesium). And there's no guarantee there are people on the planet, let alone an advanced civilization. Using my "Stargate-like" assumptions, we know that most of the gates lead to extremely primitive planets, if the planet is even habitable. So this is another case where the timing is more than sufficient if everything lines up, and worthless if it doesn't. 13. **Use the Dimensions of a Dollar Bill**. Assuming you have any such items on you, this is certainly an excellent suggestion. But you have to know the length, weight, etc. of such items for them to be useful (I have no more idea of the length of a dollar bill than my own finger). And you have to have these components on you as you get shoved through. This isn't an answer so much as a "how to help with other answers" suggestion. It's certainly good advice, but the question doesn't specify we have these kinds of tools so we can't presume we do. **How To Maximize Survival Odds** > > Consider that your daily activities are going to be hunting, gathering, fishing, etc, just to stay alive, and possibly running and hiding from alien predators. Your first few weeks on the planet will be one hellish blur, and by the time you get into a normal routine (assuming you even survive, which, let's be fair, you probably won't), any connection between Earth time and alien time will be long gone. > > > One of the comments suggests that survival is trivial. It might be. You could land in the literal Garden of Eden that was taken from us and placed on this planet thousands of years ago. But it's probably not. You have no way of knowing what's edible, what's poisonous, what's edible but totally worthless, etc. You can certainly just eat a bunch of everything, then use binary search methods to figure out what made you sick. But if you're throwing up all your food you might not survive the process. There will be alien bacteria your body isn't used to fighting. You won't have immediate access to distillation methods, and most people probably wouldn't figure out anything better than boiling the water for treatment at all. That super-clear river water will probably make you very sick at first. You could land in the middle of a desert. Or the arctic. Or anything in between. There could be *extremely* dangerous predators on the planet, or human-sized carnivorous plants. Or RouS's. Another comment mentions that "it's the only ticket back" and assumes that means people will automatically find a way. Unfortunately, that only works in the movies. While perseverance and the will to live certainly help, they can't magically turn a person into a chemist or engineer or teach them advanced physics or math skills. Nor can they generate a fire out of solid ice, or food out of famine. > > Your best bet is to stockpile food and water in an area near the stargate, then camp out right next to the gate for the last several months. But that assumes you have the materials and knowledge to keep food fresh for a couple months. Depending on the local season, you might be able to harvest fruit from trees that grow near the stargate. > > > Various sources I've read say that it takes between 1 and 10 square miles of land to support one person doing hunter/gatherer survival methods, so you could be *very* far from the stargate when it opened if you were out hunting. You would really want to transplant as many fruit and vegetable plants as possible to an area right next to the stargate, and keep it protected from the local fauna. You could set up traps and lures to hopefully get meat with spears or a bow and arrow, but you wouldn't want to leave the immediate area once you were close to the jump window. > > > A commenter suggests 10 mi² is a circle of radius 2 miles. However, it doesn't really work that way. First, the wildlife isn't going to happen to congregate in a perfectly-symmetrical circle around the stargate so you can slaughter them. They're more likely to be concentrated near lakes, rivers, and valleys in a more linear arrangement. Second, the nearest concentration of wildlife might be many miles from the stargate. Third, animals tend to migrate with the seasons, and random events, and the fact that you're murdering them, so you'll have to keep up, which could lead you hundreds of miles away. The same comment also suggests you could always run 2 miles in 30 minutes. There's no guarantee the gate will be open 5 minutes, let alone 30, so you don't want to rely on that. But there's also no guarantee you happen to be in an area with relatively flat ground between you and the gate. If there are a few cliffs in the way, it could take hours to go 2 miles. And there's always the possibility of a major strain or break. Also, there's the issue of season. It might be great near the stargate when you arrive, but the middle of the worst winter ever when the gate reopens. You'd really want some kind of greenhouse going near the stargate for this, although it could be nearly impossible to pull off. > > Depending on the planet, and where the stargate is located, it might be impossible to survive very long near the stargate. In this case, you'd best hope you can run from your camp to the stargate before it shuts down again. And practice that run so you can do it as fast as possible when the time comes. > > > As an addendum, it's always possible the nearest reasonably-habitable zone is dozens to hundreds of miles from the stargate. A comment somewhere on the page suggests Earth might send someone through to re-open the gate from your side. In this case, it would be advisable to leave messages around the stargate explaining where you were so they could signal you or come get you since you probably won't happen to check the gate just as it opens. [Answer] The only measurable thing you have with you is your body, but you won't want to rely on it. Certain bodily functions happen at a generally dependable rate, at least over the course of a year. Hair growth is one, though accurate measurement may prove difficult. Your pulse is another stand-out candidate, particularly because it is discretely countable. This isn’t going to always be accurate, however, since the gravity and atmospheric makeup of your new planet may not be equal to Earth and could feasibly affect your resting heart rate. With a significant portion of your concentration you might be able to track your pulse, but as soon as you become heavily active it will become a less stable timepiece. You will also lose track of large swaths of time when you fall asleep. You may be inclined to simply assume it was an 8 hours (or your equivalent back-of-the-envelope heartbeat conversion) rest, but the stress of your situation and the differing solar cycle are almost guaranteed to cause a wide array of fluctuations that lead to multiple hours of error a day. Constructing a physical timepiece is a necessity, but it suffers from the same core problem as manual tracking: your base units of measurement can’t be guaranteed to be constant or accurate. Even if your timekeeping was only off by thirty minutes a day, your estimation of when the gate reopens would be off by more than a week. I strongly recommend you build base camp at the foot of that gate and never let it leave your line of sight. [Answer] **From freshman astronomy, you remember that the period of Delta Cephei** (a cepheid variable) is 5.36 days, doubling its brightness at maximum. You can observe this by eye if you can find Delta Cephei. Unfortunately, finding a known star is going to be hard if you're too far away from Earth, since the constellations will be distorted. [Answer] Unfortunately no, there is no way to measure an Earth year on an alien world due to possible time dilation (which affects everything, including atomic clocks). As we all know from the movie Interstellar (or a layman's knowledge of general relativity), 10 minutes on a world near a black hole can be several years in Earth time. And, special relativity notes that a galaxy moving at a significant fraction of the speed of light would also provide plenty of time dilation for our traveler. So both speed and gravity can affect the passage of time. Unless you know the difference between the alien world's and Earth's time frames there is no way to predict the opening of the stargate. Remember, even spacecraft orbiting Earth are affected by this phenomenon so another world would almost assuredly be different - the only question is, how much of a difference would there be? [Answer] **Talk fast** (literally) If there's a stargate, there is a good chance that there is a civilisation also. An Earth year gives you time to explore before you return and set up camp next to the stargate. Find the locals and make friends with them. Any civilisation will have its own means of time keeping so your priority is to synchronise your time with theirs. Then perform the necessary conversion and allow a good margin for error. As others have pointed out, you have only your body to rely on and most bodily functions are variable in periodicity. Therefore you need to know a constant. **Solution** You need to prepare before your travels but that's only sensible for any gate traveller. 1. Learn a long piece of poetry or a passage of Shakespeare. You must learn it perfectly and be able to recite it without stumbles. 2. Practice it many times getting faster and faster. Keep a graph of your progress. When your speed of recitation has peaked, measure the overall time that it takes. 3. Fine tune the length of the text to last a time period you choose, for example an hour. You don't have to do this but it just makes later calculations easier. 4. You now have a constant that depends only on the physical constraints of your vocal apparatus. Maintain speed by practicing every day at full speed and time yourself. 5. Work out the mean error. People who go for world record speaking contests get down to a remarkably constant rate so the error is likely to be 'small'. (Note: I say this from memory from an interview I heard a few years back. It would need research to back it up but I'm pretty certain it's true. The same applies for athletes, they tend to peak at a fairly constant level.) Now and only now are you ready to journey to other places. 6. If you are alone on the planet, you have a PGTC (pretty good time constant). You must synchronise with local astronomical or other regular events. If there is a friendly civilisation, you can synchronise with their time system and from then on rely on their time-keeping. Allow a generous amount of time for error and then spend the intervening time building relationships and supplies to prepare you for the time you decided to encamp next to the gate. **Update** If you don't have the time or patience or ability to learn long portions of verse, there is another way. Hand-clapping has a maximum speed for each individual (there are world records for this as well!). Practise your hand-clapping before the trip and measure your **maximum** rate over a few minutes. Again this removes the uncertainty of autonomous biological processes. This gives a very quick estimate of time over a relatively short period but it can be extremely accurate and it is better than relying on natural biological clocks or mechanisms. [Answer] Since there is no way to know the relative distances and velocities of Earth and the planet you're on, Special Relativity tells us that we can make no assumptions about simultaneity. Even if you can somehow manage to bash some bits of rock together and make a Caesium clock, there is no guarantee that someone measuring out 31557600 seconds (which is one year) on Earth will take 31557600 seconds to do it from your point of view. All that is guaranteed is the ordering of events, not the intervals between them. From your point of view, you could be waiting 10 centuries or 10 minutes. Or you could just take greater care when passing by open stargates. [Answer] Assuming that the stress of your unusual situation has elevated your pulse rate by an unknown amount, desynced your period (if you are female), or any other natural time measurement. We can calculate the period of a pendulum as 2 pi SQRT(L/g). So if we know L and g, we have our clock. And fortunately, we can calculate g if we have a ruler. Gentlemen, lets admit, we've all measured 'it' and know exactly how long 'it' is. Don't forget that self measurements typically overestimate by an inch or so. Ladies, (to continue my theme of being sexist), probably know your measurements as appropriate to fit clothing, find some string-like material that you can wrap round your waist for a calibrated ruler. In fact, just use that string as the pendulum. Now, we need to calculate g. The best bet will be some sort of projectile motion. Jumping, spitting, peeing (yes, this post went rapidly downhill), throwing a rock could all be used to determine a total distance travelled by a projectile thrown horizontally using: $d = \frac{v \cos \theta}{g} \left( v \sin \theta + \sqrt{v^2 \sin^2 \theta + 2gy\_0} \right) $ Of course, you will have to know the distance that one of these projectiles traveled on Earth in order to calculated launch velocity (and then use that launch velocity and the distance on the new world to calculate g), so I hope you know how far you can throw/excrete something. Plug in our calculated L and g into the pendulum formula and we have a working pendulum. From there, it's some simply gears to get us a clock and calendar. This avoids us needing to directly measure/assume anything to do with speed or time, because those are hard. [Answer] Can you dial the gate? Ether with the [DHD](http://stargate.wikia.com/wiki/Dial_Home_Device)(**D**ial-**H**ome-**D**evice, or the round thing with the many buttons with constellations on them next to the gate), or if thats deactivated/missing and you're in the Milky Way Galaxy you can manually dial the gate (Pegasus Gates don't have that feature) by turning the ring by hand (but be aware that you have to [General O'Neil](https://en.wikipedia.org/wiki/Richard_Dean_Anderson) a power source). If yes, you already have a pretty reliable way of measuring time, because a stargate will stay activated for 38 Minutes (see SGA Episode ["38 Minutes](http://stargate.wikia.com/wiki/Thirty-Eight_Minutes)" for details) if nothing passes trough. So you dial the gate to a random address(could take some time to find a working one though), make a sundial(see nitsua60s answer) with that measurement. And viola, you have a (rough) way to measure time on this planet. [Answer] # [Shave Your Head](https://www.wikiwand.com/en/KISS_principle) 1. Shave your head 2. Use the inseam of your pants to cut a 6-in strip of cloth 3. *Survive* 4. Come back when your hair is 5.5 inches 365 days is a *long* time to survive and the first couple days will be crucial (you'll be at your peak). Depending on the environment, hygiene and safety might necessitate a buzz anyway. [Keep it simple](https://www.wikiwand.com/en/KISS_principle). Since the hair on a human scalp grows about [6"/yr](http://www.webmd.com/skin-problems-and-treatments/hair-loss/science-hair#2), come back when your hair is 5.5" and chill for a month. --- ### Sidebar National parks in the US have an overall mortality rate of [`0.26` deaths per `100,000` visits](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1304948/). If we are generous and assume 'visit' is an 'all-day visit' and assume that `365` consecutive 'all-day visits' won't increase this rate, then we would expect `94.9` deaths per `100,000` or about `1/1,000`. Now instead of a planned, year-long visit to a national park in the US, you are on an unplanned, year-long exile to the wilderness of an alien planet. Figuring out *when* you are going to be rescued is inconsequential to figuring out **how** you're going *to survive*. [Answer] I just though of another way to find duration from distance: echo. (Here again, you need first a proper distance measurement, and a relative time measurement (other answers cover that)) Find a place that has significant echo, measure the time of roundtrip of the sound, measure the distance to the other side of the cave/cliff/thing. Sound travels at ~340m/s, depending on the pressure and temperature (which you can estimate) Another one, which requires a bit of luck. Build a big lightning conductor on top of a hill (if you can find some metal, it will be easier (and not entirely impossible, a tribe of inuits is known to have used metal cutlery without access to mining - from a meteorite)). Go far, but make sure you can see when the lightning falls on your device. Measure the time of sound propagation. (again, need a device to measure relative time). (You need a planet with thunder, of course). Works also with explosions, or rock falling from a cliff, as long as you can measure the time between the visible and the audible. [Answer] Overall, you always need 2 of the three following: * Gravity * Time * Distance Distance is easy to estimate. Your belt and pants, your feet length, your height, your finger span, you usually know a few measurements. Relative time can be estimated too, using various mechanisms. A pendulum, counting your heart beats, singing in rythm (those 2 can also imprecisely estimate the absolute time). Absolute time requires something more, and can be obtained by knowing the gravity. Not very precise, and very time consuming, but you can estimate the mass of the planet (and therefore its gravity) using the [method Eratosthenes used](https://en.wikipedia.org/wiki/Eratosthenes#Measurement_of_the_Earth.27s_circumference) and assuming that the density of the planet is somewhere between Mars (4g.cm^-3) and Earth (5,5g.cm^-3) (not very precise, like I said). Gravity gives you the duration of a free fall (find a cliff of some sort, measure its height). You will need a precise timepiece at some point to measure the duration of the fall and extrapolate to a day. A pendulum could work, or may be just your heart, as long as it stays globally regular for a good period of time. [Answer] I'm going to assume that you have access to water. If not, I don't think you'll make it a year anyway. If you do, you can build a [water clock](https://en.wikipedia.org/wiki/Water_clock): [![Persian water clock](https://i.stack.imgur.com/TbZNH.jpg)](https://i.stack.imgur.com/TbZNH.jpg) Make a bowl out of clay, metal or wood with some extra weight (you have a whole planet at your disposal, I'm sure you can find something) and poke a hole in the bottom. Do a few runs, counting mississippis to see how long the bow takes to become submerged. This is your smallest unit of time, which you can convert to seconds. Just spend a couple of days watching the bowl and emptying it each time it becomes submerged, and you can figure out how long a day is. [Answer] You can only go forward through a stargate, so you should hide and camp near it. When you hear noise, either Earth is dialing you to send someone that dials back, or the stargate is programmed to dial Earth automatically within a year. In the mean time, you'd eat, protect yourself (probably underground), farm and gather resources. You should stop any activity that requires you to move away when you realize your hair has grown about one of your finger's length, given it should grow about 15 centimeters per year (so pick your finger wisely). By then, you'd wait for the stargate to open, consuming what you have gathered. You don't have any reliable way to measure the passage of time, but you have many rough ones based on distance. Measuring distance is tangible, or at least a much less rough estimate than time alone. For instance, rhythm or internal clock is very susceptible to failure, you can't really count the time it takes for a rock to fall of a multiple of your height, heartbeat depends on effort, stress and tiredness, etc. Here are somethings you can measure the length of to determine the passage of time: * [Your hair grows about 15 centimeters or 6 inches per year](https://en.wikipedia.org/wiki/Human_hair_growth) * [Your finger nails grow about 3 millimeters per month](https://en.wikipedia.org/wiki/Nail_(anatomy)) If you have grown finger nails, you can bite your finger nails up until the white part is gone, and roughly estimate the length of the regrown white part * If you're a man and you've shaved your beard recently, you should know about how many days it takes to grow e.g. a 1 finger girth of beard Likewise if you're a woman, but replace the 1 finger of beard with e.g. 1 or 2 millimeters of leg hair, or visually, whatever you usually let grow * If you somehow know how much time you take to relieve a full bladder, you can drink all the local water you can and go for it It's equally good to know how much time it takes until you feel the need to relieve your bladder since you filled an empty stomach with water If you can't find potable water, measuring the passage of time is the least of your worries --- In case you can think of other things that take a few minutes and at most one hour with relatively good reliability, you could also build a big hourglass: a base and a funnel made of tree cork, or leaves and sticks, or a cone-rolled sheet of malleable plastic or metal, filled with sand or dust. Once the timed task is done, you'd remove the rest of the sand, and perhaps a handful more (see last paragraph). You can then build a weight scale with relatively regular sticks standing on a middle point, and measure just as much sand, and join all the sand together. Do this until you get something above 8 hours worth of sand; remember, you'll always double the sand, so be careful not to overweight. You'll have to rotate or refill the hourglass all the time, so you better sleep well right after a rotation. Otherwise, stick to the longer term estimates. --- As a final hint, always make your estimates **below**, because you'd rather be early than late for the stargate opening. And keep calm, as that will allow your body to function with less inhibitions, thus making your early time estimates more accurate (yes, because the Earth year doesn't wait for you to find a good estimate, you must take into account the time you spend from the first moment the stargate is closed). [Answer] # Get some help from the locals to learn *c* This is a little bit of a stretch, but can you find some friendly advanced aliens who can measure the speed of light to at least the same level as we could in 1878? And do you remember the speed of light to an accuracy of at least 3e+8m/s? Communicate with the aliens until you learn the speed of light in their units, and then you know one very useful constant. Remember during this time to *carefully count the number of local days which have passed*, knowing this is critical. ## Use your body to calculate 1m Next problem, can you find how long a meter is? I hope you didn't come out of the stargate buck naked, but if you did you'll just have to use your own height in meters. If you aren't naked perhaps you have a handy tape measure or ruler on your person, otherwise probably best to stick with your height. This wont be perfect, I'll give an estimate of inaccuracies later. ## Calculate the ratio of Earth to Alien days With the length of a meter and the speed of light in human units, you now know how long 1s is (or at least you can calculate it - hint it is the time light takes to travel 3e+8m). You'll need to reconcile these units and numbers with the alien units and the alien speed of light and the number of alien seconds in an alien day, but if you passed high school calculus it shouldn't be any difficulty at all. The harder part will be learning the alien language. If you are a dunce in maths but a genius in languages, get the aliens to calculate it for you! All you need to know is the ratio of earth days to alien days, then you will know that 365 earth days is 217 or 461 alien days or whatever. ## Count down the alien days Once you know the ratio of an alien day to an earth day, continue to count down the alien days until that special day arrives. ## Margins of error How accurate will this be? The main problem is the margin of error in your height, assuming you (correctly) remember your height as 200cm but with a margin of error of 0.5cm, then your numbers could be out by as much as 0.25% (it's worse for short people), over a period of 365 days, this could be +/- 0.91 days (22 hours), this incidentally is a much higher margin of error than the error which comes from approximating the speed of light as 3e+8. If you were lucky enough to arrive with a tape measure, you could enjoy significantly higher accuracy. ## Camp at the gate Even in this fabulously fortunate case, of having helpful aliens who know the speed of light and help you to calculate the ratio of earth days to alien days, you still only get an accuracy of about +/- 1 earth day. So it would be advisable to arrive a day early and camp out at the stargate. [Answer] Water will be an essential ingredient, i just assume there is plenty of it, otherwise you are screwed anyway. **Preparation** But we get to it later, the most important thing is to start measuring time right away in *some* way. Before you go to sleep you should hack together some "clock" that can run unattended for at least the duration of your sleep. A sundial. How fast will water drain from a bamboo trunk with a tiny hole in it? How fast will water evaporate from a hollow rock? How fast will an ant-like insect colony consume an apple-like fruit? Dont worry about the details, you can calibrate those methods once you found a more exact timekeeping device, you have one year to do so. And dont rely on a single method, run them all in parallel it will reduce the error margin and a sudden rainstorm wont wipe out your progress. Now, after you spent 3 hollow rocks = 7 apples = 34 bamboo buckets worth of time on gathering supplies and making some tools, its time to do science. First, stand next to a tree and mark your height, you should know it up to $\pm 1cm$, thats better than 1% precision. Next we will be using heat transfer $\frac{dE}{dt} = -kA\frac{\Delta T}{\Delta x}$ to measure time Wait, what? All we can measure so far are lenghts but here we also need energy and temperature, how the hell is that gonna help? Thats where water comes into play, its very easy to manipulate and its properties barely change under most circumstances. * Freezing point at 0°C, this is affected by impurities like salt, but those are easy to get rid of by distilling the water. * Boiling point at 100°C, this [barely changes with atmospheric pressure](http://docs.engineeringtoolbox.com/documents/926/water_pressure_boiling_temperature.pdf), only by 5°C if the pressure changes by 20% and at most by $\pm 20°C$ in survivable range. Fortunately we can measure that too (more on it later). Impurities dont affect it that much, a saturated salt solution has its boiling point raised by only about 8°C * density $\rho\_{water} = 1\frac{g}{cm^3}$ and $\rho\_{ice} =0.917\frac{g}{cm^3}$. Solids and liquids are pretty much incompressible so even at tenfold gravity the values will be the same for practical purposes. * thermal conductivity $k\_{water}=0.609\frac{W}{mK}$ and $k\_{ice}=2.22\frac{W}{mK}$ * Latent heat of ice $334 \frac{J}{g}$ **Process** Now we are good to go. First make a few ice spheres, use a string to make sure they are spherical and same size, dip them in water to make it even more spherical, store just below 0°C. Next make a fire and boil a big bucket/bison skin/giant snail shell full of water, you dont want it to cool too much from the ice. Finally, start a pendulum, throw in an ice sphere and stir it like your life depends on it, because it does. Count the pendulum swings until it fully melts. Done. **Evaluation** Simply putting ice in hot water melts the outer layer and cools the surrounding water, it is circulated away by convection but very slowly. By stirring we make sure that the water in contact with the ice is always at its boiling temperature and makes the calculations much easier. *did some math here but i messed up, might expand on it later, for now a summary* The total flux of energy into the ice sphere of radius $r$ is $\frac{dE}{dt} = h\_{eff}\cdot 4\pi r^2 \cdot \frac{T\_{boil}-T\_{ice}}{\Delta x} = \alpha r^2$ The total energy required to melt an ice sphere of radius $r$ is $E = \frac{4}{3}\pi r^3 \cdot \rho\_{ice} \cdot 334 \frac{J}{g} = \beta r^3$ expand the differential: $\frac{dE}{dt} = \frac{dE}{dr}\cdot\frac{dr}{dt}$ and plug in previous equations: $\alpha r^2 = \frac{\beta}{3} r^2 \cdot \frac{dr}{dt}$ and we get $\frac{dr}{dt}=3\frac{\alpha}{\beta}$ that is, the radius of the ice sphere shrinks at a constant rate. According to an experiment performed in a teacup it is around $1\frac{mm}{s}$ Heat transfer by thermal radiation might play a non-negligible role here and makes the computations more difficult therefore its better to determine the coefficients $\alpha$ (depends on atmospheric pressure) and $\beta$ before the journey As mentioned before, if the atmospheric pressure is within $\pm20\%$ of earth pressure, the error will be at most 5% and you will be able to calculate the date with up to 3 weeks precision [Answer] **Use your jetlag.** This is not nearly accurate, but can get you to a magnitude of order at least. With different rotation, revolution around the 'sun,' and all other seasonal variations, you cannot rely on anything cosmological *at first*. Your initial sleep cycle will be hopefully a healthy 8 hours. If not, you will have to average out your days. You KNOW when you've only had a nap, vs. a four hour nap, vs. a full 'nights' sleep. Take that measurement and align it with the daily passage of time. If it appears to equate 8 hours with three days (fast rotation), calculate that out, and so on. It's not nearly accurate, and I know you were looking for something more accurate, but without anything from Earth, it will let you know with greater accuracy a range of when you should be back to your gate. Or you could just hang out there. [Answer] **Use your body's internal clock.** Go to sleep 365 times and you'll be in generally the right place. This approach requires lots of darkness so that you're circadian rhythm doesn't adapt too much to the new planet's night and day. [Even in periods of extended sunlight, human bodies default to a 24 hour cycle](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3793275/). Keeping time is as simple as scratching off marks on a wall every time you wake up. This should also help you get a handle on the local day length. A few people will desync from the 24 hour cycle and other people will find that they have a >24 hour cycle. [Answer] ## Use statistics! You can't count to 60 and expect it to be a minute. You cant sleep one night and think you got a perfect 8 hours. But you do have a year, and you can start building datasets. You know the relation between all your Earth time measurements. Now start forming approximate connections - a sundial will tell you about the Alien day, and its hours, and its minutes. Does it take 60x60 seconds to cross a twelfth of the dial? Does this change in the morning or evening versus midday? ## Exploit relations: After a week you wont have a conversion chart, but you'll *know* if a day is longer here or not. You'll also be able to guess by about much, since that 'hour' happened too fast, or the nights lasts too long. The drift on your circadean rhythm will also help. If each morning comes too soon or not soon enough, or each evening, these are hints. If there are moons, track how long each one takes to drift across the sky, relatively. Do they make it from Alien-east to Alien west, or vice versa, before the ngiht ends? Do they make multiple passes? ## Have the terrain tell you: Observe the animals and plants and whatever else lives on this world. Draw relations between them and known creatures of Earth. Are they larger? Smaller? Do trees have leaves all the way around, or do they favor a side. Which way to birds fly more often? There is an unending amount of data to be collected from the environment, ever living things adapted to life here, and can tell you how to survive given the natural time. ## Put it all together. You can count Alien days, hours, minutes. You can draw the relations. From there, you can guess about how many Aliens days equal 365 Earth days. Depending on how much skew you think you have, you can pad yourself which 5% or 10% earliness, or simply try to underestimate time so that you are guaranteed to arrive back early. ### Example: Counting off rough minutes, coupled with a 12-hour sundial shows that each hour is about a third longer than you think it should be. You observe a moonrise and moonset every night, which at least 30-60 minutes to spare on either side. That would lead to two or three tide cycles in a day, and you can chart that on any body of water. If its truly periodic, you can find out roughly what time of day it is that way too. Both together and you can guess that a day is about 30-32 hours; you have about 273-292 Alien-days to wait. If either method contradicts the other, observe more and take more data, averaging the two. ## Go Explore! Now that you have a general timetable, go enjoy the local scenery and try not to get detained or captured. Also, they might be able to sharpen your time-conversion, or at least provide some paper so you can write all this down. Good Luck! [Answer] **Action VS Time** With any luck, you have vast open terrain at hand. AND either way, you won't be staying sitting at the portal's location for a full year. (You lazy )@(#\* ) So start moving those feet. Now if you're used to walking a lot, you know what speed you travel at. And anyone with a bit of practice can be able to accurately judge distances up to a kilometer. So if I know it should take me about an hour to walk say 6-7 kms at a normal pace, I can judge a km of land, and walk back and forth along it to total what SHOULD be about 2-3 hours. (You dont want to walk too long otherwise fatigue starts having a bigger effect etc...) The back and forth is for a reason. You can use shadows to apply that 2-3 'earth' hours to this new planet's day cycle. (maybe it equaled what seems like 1/5th of a day, maybe 1/40th 'yikes' ) repeat this activity for a couple of days, and keep track of shadows regularly. Eventually you'll have a very good grasp/guess as to the ratio of earth days versus this new place days. *'Ok 1 new day = .75 earth day so I have to be back in 275 days or so, I'll say 250 to be safe.'* **EDIT** A lot of people keep bringing back : 'But you might be totally exhausted etc.. so your answer is invalid' I feel like you are confusing 2 things. Physical state, and ability to judge time doing something you know well. If you know it takes you 10 minutes to walk all the way to your bus stop. You'll know if you walked it in 10, or a bit more or less. Regardless of if you are completely out of breath and tired, or perfectly fine. This isn't much different then @chasly from UK's answer where he uses speech to measure time. You could also argue that if he's exhausted by simply being there, it will also affect his speech (try reciting something very fast when out of breath.) And that the difference will have a greater impact since the time measure is smaller (and has to be repeated more in order to obtain any useful time-frame) Both our answers state doing something you can easily judge time against through habit. This is not something thrown completely out of whack by sudden physical exhaustion. SURE you might be slightly off, but that holds true without the planetary differences. I guess I could've explained better right off the start (I changed the header to reflect this). But in my case, I'm good at guessing elapsed time against anything I do physically, especially walking/trekking. If that doesn't work for you because it's not something you are used to doing - use an activity you are very used to. [Answer] Admitedly, this is not a great answer, but was not covered by anyone else. I am just adding on top of other answers. If you find some fine sand and is able to carefully melt it, with some days of work you may be able to produce glass, and eventually an hourglass. Ideally, you could produce a big hourglass that takes somewhere from 20 minutes to an hour to empty its upper half. The hourglass, per se will not tell anything about the relation with Earth's time, but you could use it to refine the measurements and reduce the error margin from other methods, like sundials, water clocks, counting heartbeats, counting mississipis, singing your preferred song, etc. Further, you could create many different hourglasses with different periods and then choose the best ones and also crosscheck them. However, this would probably require that you already have that skill when you arrive. Although it is possible, you will unlikely to be able to learn this yourself on the planet in say, 6 months. **Edit:** Although an hourglass indeed needs a non-zero gravity to work, you don't need to measure it or even care about it's value. You could just measure the time needed by the sand to empty the upper half by counting heartbeats, counting mississipis or singing your preferred song while watching the sand falling to relate the hourglass time to seconds, regardless of what is the gravity value. Then, if it takes, lets say 10 minutes, you could use something like "flip the hourglass 6 times" to measure an hour in order to place a mark in a sundial or do something else which requires time intervals too large to mentally compute. [Answer] **Atomic Clock** I think that a highly likely possibility has been missed. There is a very good chance that you will land on a planet with a high level of technology. If there is a working timegate then this is almost certain. **Answer** Any technologically advanced society will know the speed of light and have atomic clocks. These will work at the same rate anywhere in the universe. Provided the traveller knows the speed of light then everything else can be translated into local time units. Even if the technology is only at 19th century Earth level, our traveller can talk to their scientists and pass on the necessary information to make a measurement of a suitable constant. They will be grateful that their science has been boosted and will be predisposed to help him return. **EDIT** People seem to be shooting first and asking questions afterwards. Or rather, in this case, they are raising an objection but down-voting before waiting for an answer. The assumption seems to be, "I know better therefore there can be no valid answer to my objection." When I have a minute I'll do some actual maths and show how the calculation would be done and the amount of error that can be expected. [Answer] First thing first: put a stick in the ground and mark where the shade falls. That way you will know exactly when you arrived. Then... # Go to the loo Seriously, if you usually go to the loo at regular times you can compare the length of the alien's day to your. Obviously the new environment will affect your functions but you should have a couple of days of "normality" until your body gets used to the planet. Use a sundial to measure the alien's day, divide the day in equal parts and then mark at what alien-time you need the loo. Then it should be easy enough to do the conversion. [Answer] Other answers have gone over details, including math, of building a clock or whatnot provided you have some calibration standards for our unit system, not for time but for other kinds of units, like the length of a pendulum. I'll elaborate on finding these known units (and other junk that might further the plot). ## You really have *nothing*? In *Have Spacesuit, will Travel* the teenage boy finds himself captive. He has among other items in his pocket a dollar bill. He knows the dimensions of such standardized objects, and uses that to measure his cell. The feasibility of his escape requires considering a volume of water, and rather than just invoke cartoon physics, the author elaborates on figuring this out. Although not wearing a watch and the smartphone and any all electronics are fried, he might have other items on his person, of known *size* or *mass*. Perhaps a pocket multi-tool is marked with a ruler along one edge and happens to be stamped with its mass for use with some more typical use. Perhaps a neck chain piece of jewelry happens to have specs that he knows. Coins might have a known mass as a matter of course, even if it's not simple; e.g. 32g of (valuable metal) with the composition being 0.87 (value-metal) of the coin. **Take a careful inventory.** Consider *everything*, even things that would normally be unnoticed: the lint in your pocket might just save your life. Maybe you'll remember buying "24-inch" shoelaces. You might know the length of your belt counting up to the noch where you normally hitch it. What you don't? Well, the label in your underwear will tell you. [Answer] The most important thing to figuring this out is how long is a local day. It is pretty easy to keep track of days, I won't bother telling you how to do that, but the key is figuring out how long a single day is. The best way to do this would be to use some sort of a pendulum to estimate how long a second is, and use that to figure out the other relevant information. I'm going to assume that you don't have a mastery of physics, but do have some knowledge of principals. I know most grandfather clocks I see have a pendulum of about a meter. I know there is some relationship to gravity, but I don't really know what that is. Depending on the length of the local day, I could stay up to count the entire cycle (If short), or else figure out the number of swings over some period of time, perhaps by marking the position of the sun between elements, and using that. As for the gravity, I'm going to assume that I would know at the very least what direction the change in gravity was. I could try jumping, and see how high I jump. I don't know really well how high that is, but I would guess a couple of inches. If I could barely jump, I know gravity is higher, if I jump really high, I know it's lower. I would use the reciprocal of the difference to estimate the gravity difference, as a guess. I'm not sure how the pendulum differs with gravity, but I would guess it would be a linear factor, because distance is directly proportional with acceleration in such systems, and that gives a time estimate. How would I measure the meter? I know my waist size pretty accurately, and that is close enough to a meter that I could fudge it to get one meter almost exactly. The exactness wouldn't really matter all that much, however, because I'm not quite sure of all of this. I could further calibrate the pendulum clock I built based on my heart rate. I'm not really sure how accurate that would be, but it would take into account some of the stuff that I'm missing. I also am a runner, and I know both my walking speed, and my jogging speed. These vary by around 15 seconds per mile, but is reasonably accurate. I could take my distance of measurement, and use this to chart out a course. That course would give me a reasonable estimate of time. Okay, so I did the above without reference to any outside materials, to give me an idea of what it would take. How accurate was I? First of all, a pendulum would be 2 seconds period, not one second. The distance is rather close, however, 99.4 cm. Assuming my extra sensing could tell a difference of a factor of two, and I could build within one inch, that would give me a precision of 5%, give or take. As for the gravity measurement, that would potentially be very rough. In addition, my sense of physics was off, the period is proportional to the inverse of the square root of gravity. Woops. Still, this would actually likely work in my favor, as any changes in gravity would have a smaller effect. My resting heart rate fluctuates by at least 10%, so that wouldn't be really useful. Bottom line is, I think in a completely stranded situation, I could probably only estimate the time to within maybe 10%, assuming I can correct some mistakes in my knowledge.. With some accurate technology, I might be able to be a bit more accurate, especially if I had proper physics resources. In particular, with my pretty accurate meter estimation, and knowledge of light speed, I could probably be very accurate, to within a couple of percent. [Answer] If your resting heartrate is a known quantity (say you're a runner) that might be a good source to calibrate a pendulum or waterclock or hourglass from (if inexact). If you happen to have a pacemaker, you could definitely calibrate from your heartrate. You might be able to calibrate for gravity in other kinds of calculations if you know your exact height (to use as a base unit for measuring height), and the mass of whatever you're going to drop (maybe yourself) or its weight on earth (since you can use that to figure out the mass if you happen to know G). From the force (perhaps measured by displacement, or an impression left in clay) you can derive the acceleration, and from the acceleration figure out the gravity. Its not gonna be precise. If you're much better at science than I am, you might know some way to put together a quartz or salt crystal based resonator of some kind. I don't happen to know in detail how that would work. [Answer] If you are an amazingly talented drummer the problem might not exist. Some drummers are able to recognise the speed of different beats by ear to an insane degree of precision as well as being able to reproduce it at will. Not all speed might be known very precisely, but some which are very common and often played will be. One that is commonly recognized is of course.. 60bpm! [Answer] Do you have perfect pitch? Sing an A and ask the natives what frequency it is in their units. Their second will be equal to 440/(frequency they say) of our seconds. ]
[Question] [ I recently played my way through the *Mass Effect* game series, and one of the ideas I found most intriguing was the emphasis placed on "time capsules" sent from one cycle to the next: not only did several Prothean messages last until the in-game present, but presumably each cycle had done the same in an unbroken line, at least going back as far as the development of the Crucible. Assuming modern-day technology (not *Mass Effect*-era), would it be possible for humans to leave a message that would confidently be received 50,000 years in the future? Do we have any storage mediums that would last that long, or preservation techniques that could work on that scale? Obviously there are ways that a message *could* last that long (such as a rock carving inside a dry, untouched cave), but things happen. Caves fill with water, earthquakes crack them open, etc. But if we had a message that *must* survive 50,000 years into the future and still be understandable, what would be our best bet for delivering it? [Answer] My first thought is **redundancy**. You shouldn't send just one copy of the message, you should send thousands and through different methods. Some thoughts on possible methods: * Rock carving in a protective sheath (e.g. amber or a similar substance). * Shoot rockets to the Moon and Mars (vacuum doesn't decay things the way that atmospheres do). * Build satellites in orbit. * Bury on the sea floor and in swamps (hey, it works for dinosaur bones). * Hang them in houses for anthropologists to find later. * Scatter them around the active volcanoes in Hawaii (think about Pompeii-style preservation). * Impress upon your children that the message needs to be preserved verbatim and have them make copies. Deliberately start a tradition of each generation making verbatim copies. Again, let me say that the most important part is redundancy. Any single message is vulnerable to destruction for any method of transmission. Make as many copies as you can. That way you have a better chance that at least one will survive. [Answer] There's a very specific existing case study of nearly this exact question. In the 1970s, the US Department of Energy began investigating what is now known as the [Waste Isolation Pilot Plant](https://en.wikipedia.org/wiki/Waste_Isolation_Pilot_Plant) as a means of safely storing radioactive waste for the next 10,000 years. Considerable thought was put into the topic of signage: how to indicate to future generations, for whom the very concept or science of radioactive waste may be lost, that the materials buried in this location remain harmful in a very literal sense. There are some [interesting papers](https://web.archive.org/web/20170513191808id_/http://www.wipp.energy.gov/PICsProg/Test1/SAND90-3036%20Expert%20judgement,%20human%20intrusion.pdf) from researchers at Sandia on the topic. You can read [some excerpts](https://web.archive.org/web/20180106124933id_/http://www.wipp.energy.gov/picsprog/articles/wipp%20exhibit%20message%20to%2012,000%20a_d.htm) as well. ## Do we mark it at all? I know this wasn't specifically what you asked, but it calls into question the very premise of the exercise. Recorded history goes back only about 6,000 years. The earliest known permanent human settlements go back less than 9,000. So communicating to humans 10,000 years (or, as you posed, 50,000) in the future may simply be impossible. One alternative (in the case of the WIPP) is simply to bury the material in as inaccessible a place as possible, and assume that any civilization able to discover and uncover it will also be able to detect the danger posed. The Sandia panel rejected this on legal and (I would say) moral grounds. ## How do you ensure the message is physically durable? This seems to be most related to the core of your question, and the answer is fairly mundane. The final proposal calls for the use "granite monuments, 25 feet high" carrying etched messages, an information center and two storage rooms with similar granite markings, and, buried throughout the complex, the same messages etched on "nine-inch-diameter discs… made of granite, aluminum oxide, and fired clay." In addition, the same information will be placed in various archives around the world. ## How do you ensure the message is intelligible? The plan calls for the message to be translated into the six official languages of the UN (English, Spanish, Russian, French, Chinese, Arabic) as well as Navajo, the ancestral language of the region. ## But come on, how do you really ensure the message is intelligible? How do you ensure that future generations don't destroy the markers? How do you ensure that people take this seriously, anyway? This is, to my mind, the true crux of the matter. The obvious (and somewhat pulp) analogy is to curses on Egyptian tombs – an Egyptologist might properly translate the text, but he is unlikely to take seriously a warning threatening bodily harm due to vague invisible forces. Worse yet, the presence of the tomb encourages desecration for motives both historically minded (archeological investigation) and crassly economic (as with reuse of building materials from Roman or Egyptian edifices for more modern constructions). The WIPP panel was quite aware of such risks, and made a number of suggestions which I will simply quote verbatim: > > Each component of the marking system should be made of material(s) with little intrinsic value. The destructive (or recycling) nature of people will pose a serious threat to the marking system. > > > We decided against simple "Keep Out" messages with scary faces. Museums and private collections abound with such guardian figures removed from burial sites. These earlier warning messages did not work because the intruder knew that the burial goods were valuable. We did decide to include faces portraying horror and sickness (see Sections 3.3 and 4.5.1). Such faces would relate to the potential intruder wishing to protect himself or herself, rather than to protect a valued resource from thievery. > > > While the below messages differ from the final design, I found a certain sense of Lovecraftian poetry in their directness: > > This place is a message… and part of a system of messages… pay attention to it! > > > Sending this message was important to us. We considered ourselves to be a powerful culture. > > > This place is not a place of honor… no highly esteemed deed is commemorated here… nothing valued is here. > > > What is here is dangerous and repulsive to us. This message is a warning about danger. > > > The danger is in a particular location… it increases toward a center… the center of danger is here… of a particular size and shape, and below us. > > > The danger is still present, in your time, as it was in ours. > > > The danger is to the body, and it can kill. > > > The form of the danger is an emanation of energy. > > > The danger is unleashed only if you substantially disturb this place physically. > > > This place is best shunned and left uninhabited. > > > As a final aside, the suggestions made by a poll conducted by the Zeitschrift für Semiotik and Bechtel's "Human Interference Task Force" are quite interesting in their more far-ranging conceptions – suggestions include the creation of artificial satellites that can circle the earth for millennia, genetic coding of messages into cats, and the creation of an "atomic priesthood" to keep the knowledge sacrosanct. [Answer] I think we can all agree that whoever finds this message in 50,000 years isn't going to speak English. Or Mandarin. Or Hindi, French, Spanish, Swahili, or, in fact, any language spoken today. So we'll have to figure out a way to communicate with them in a language that *we'll both understand*. I'd look to [communication with aliens](https://en.wikipedia.org/wiki/Communication_with_extraterrestrial_intelligence) for inspiration. There have been various proposals involving math. For example, we could perhaps use prime numbers in an attempt to show patterns. Any sufficiently advanced civilization could understand that. Or perhaps we would use a modified version of binary code. Maybe we could just decide to *create* a new language, that would be easy to decode. To preserve this message, we need to put it somewhere that will protect it for a long time, but will still be open-able in 50,000 years. Paper is, of course, a good choice, but it can degrade in certain environments. Etching the message in metal is another option. Sure, you could store it digitally, but all digital devices have a limited lifetime - certainly less than 50,000 years. We could encase it in some hard material, such as metal or stone. I know that some smart-alec is going to say amber, so I'll add that here. Essentially, you need something that will survive 50,000 years untouched by the things around it - i.e. a material that's tougher than its environment. Perhaps you could put the message on a sheet of metal and encase it in pure diamond. That way, whoever discovers it could maybe read it through the diamond. Alternatively, put it in a solid glass box and encase the box in some tough, transparent material. All the ideas above can be summarized like this: Write the message in an easily-decipherable code on a stable medium, stick it in something that will last a long time, find a safe place to put it, and wait 50,000 years. There is another option, though: send the thing to space. The [KEO](https://en.wikipedia.org/wiki/KEO) satellite will (if the project ever gets anywhere) stay in Earth orbit for 52,000 years. It will then re-enter the Earth's atmosphere and, hopefully, carry a message to whoever is still on Earth at that time. (The [LAGEOS](https://en.wikipedia.org/wiki/LAGEOS) satellites will also enter the atmosphere - albeit it 8.4 million years from now; their primary function is also not that of a time capsule) You could do something *a la KEO* and put a message in orbit, where it won't be impacted by severe weather, continental drift, or those pesky humans. [Answer] I am going to derive on the things already said and add few comments: **1) The message must be interesting to pass on** Take a story about [Atlantis](http://en.wikipedia.org/wiki/Atlantis). Somewhere I heard that it actually describes a story which happened 1000 years before Plato. In other words, story old about 3500 years is still around (and people are still having arguments what and where Atlantis might be) **2) Make it into religion**: This point will help you a lot to make your message to pass on in generations. Not only people will be willing and wanting to make copies of your message, but also, your message will be translated to many languages (especially if your religion becomes popular). And also, you can make sure that your language will be still around even when [no one actually speaks it](http://en.wikipedia.org/wiki/Latin). **3) Build whole society on the message** Ok, we know about religious practices old about 7000 years, and still are somehow able to understand the language. But how did we learn about it in the first place? Well, they built the pyramids. They built the Stonehenge. They kept their awesome badass burial places behind. So, to wrap up: * Make your message into religion * make the religion very popular and mighty * Make sure, the culture and society lives on the religion. But one thing is for sure: Using those practices above will be able to pass the *idea of the message*, not message itself. Religions update as society updates, and wonders of the modern world get forgotten in the desert, or the fields, leaving no one behind to tell the stories. Also, [war happens](http://en.wikipedia.org/wiki/Aztec) so even following all the rules might get you to dead end. So, if you need the exact message to be around in 50 000 years, use means as stated in other answers [Answer] I just wanted list a few projects that exist and pertain to this question. [LAGEOS](http://en.wikipedia.org/wiki/LAGEOS) - A series of scientific research satellites which use lasers to measure the planet's shape. LAGEOS-1 is predicted to reenter the atmosphere in 8.4 million years and contains a plaque designed for review by future humanity. It was launched in May of 1974. [Memory of Mankind](http://www.memory-of-mankind.com/en/definition.html) project - Has an estimated lifespan of 100,000 years. They are storing information on inscribed stone tablets and storing them in a [salt mine in Austria](http://www.salzwelten.at/de/hallstatt/bergwerk/mom/). [Rosetta Project](http://rosettaproject.org/) - It's goal is to preserve around 13,000 pages of information in each of 1,500 languages on a disk made of nickel. The disk can be read with a microscope and is contained within a 4 inch spherical container. One of these disks is on the [Rosetta spacecraft](http://en.wikipedia.org/wiki/Rosetta_(spacecraft)) that was launched in March of 2004; although it's mission ends in 2015. [KEO space time capsule](http://en.wikipedia.org/wiki/KEO) - Has experienced several delays and has not been launched yet. Estimated to launch in 2015. It's purpose is to reenter the Earth's atmosphere in 50,000 years. It will apparently carry around 24 billion pages of messages on a DVD with symbolic instructions for how to build a reader. It will also contain a drop of human blood and samples of air, sea water and earth encased in diamond. [Answer] Encode it with some added redundancy (mutation-resistancy) and inject it in to the DNA of the several geographically distributed organisms (from single to multi cell) with the option of on some species which message manifest itself (whole or in part) some visible way (think zebra stripes as barcode or leopard with QR code). [Answer] There are many long orbit comets that pass by every 50,000 years, and the half-life of Uranium is over 4 billion years, so a powerful multi frequency transmitter encased in synthetic diamond powered by uranium stuck on a 50,000 long orbit comet could be a good long-shot, with another few stuck here in our solar system and on earth. [Answer] Even the pyramids are not guaranteed to survive that long. You could engrave something on the really hard crystal and make sure the words and the crystal are big enough to keep the shape under conditions. The degradation of the shape could be calculated by a chemist. Then put it in to a mountain cave, you need to talk to a geologist here and find the area with the caves that are really old, there are plenty, some mountains are more or less stable for millions of years. But then again, how you let the receiver know where to look for your message. And do you care ***who exactly*** is going to find and read it? And why should they care? They would care if they knew this some how helps them in their lives. So it must be ***about them***. Like we are really curious where our civilization came from, that's why we keep looking for old messages. So basically to make them interested in ***your*** message, you need to some how change their lives. And leave a track to a message. But assuming you can change their lives, which means to have some influence on the ***society***, it is easier to leave the message in the society to pass on in the form of useful idea. That's maybe why religions were created and continents conquered, the greats of the past wanted to leave us ***the message***. Since we do not know how to create mental entities that would survive in the society for so long, maybe you can choose to modify human genome, and then the scientists of the future will decode your message. But in fact, I believe that once you left your message here on Stack Exchange, it will most certainly survive for 50000 years. Because this site was created to accumulate knowledge, and is one of the first more or less successful implementations in this area, this site and the dump of all it's database is almost certainly guaranteed to be backed up and copied into all future implementations of knowledge gathering. Once they create quantum computers or even pure-energy computers or any other advances in information processing and storage will be made - most important data will be copied over from old systems. Like those floppy discs, billions of floppy discs are dead, but most of even slightly valuable data from floppies is now stored on hard discs or SSDs, in the cloud or you PC/tablet/phone. And surely future data storage devices will allow super cheap copies of whole Stack Exchange network. So leave your message here in the comments and add a hashtag #tobereadin52014. So the "Bing" of the future will be able to find it and let the whole mankind "retweet" instantly around the galaxy or whatever. And don't worry about the language, translation tools of the 52014 will easily decrypt your ancient scriptures online. You can even add some formatting and hyperlinks. But probably only few hyperlinks will still work in a distant future. At least those that link to another stack exchange page are surely safe. [Answer] According the news from phys.org [Eternal 5D data storage could record the history of humankind](http://phys.org/news/2016-02-eternal-5d-storage-history-humankind.html#jCp/%22Eternal%205D%20data%20storage%20could%20record%20the%20history%20of%20humankind%22). > > The storage allows unprecedented properties including: > > > * 360 TB/disc datacapacity, > * thermal stability up to 1,000°C and virtually unlimited lifetime at room temperature. > * 13.8 billion years at 190°C > > > [Answer] As has been said, language won't survive. Thus, don't use language in the first place, use pictures. I would a bunch of pictures made out of a pair of metals that won't corrode--not plating but images that go all the way through the metal. Once you have enough pictures to explain you can use a more compact coding scheme. You can never predict what's going to happen to any given time capsule so you make a lot of them. Put them in varied environments, including on the moon. I wouldn't put things in orbit because anything put high enough up to last 50,000 years is going to be awfully hard to detect. Make it big enough to be spotted and you're asking for it to get smashed. [Answer] Actually, an attempt has been made in the past, and we can still access the message nowadays : bible, kûran,... The best way to make a message go through centuries is to make people alienated about the fact they should spread it. Edit : This solution has the advantage of removing the message's language problem. [Answer] Place a large terrestrial object in orbit around the earth, a second moon if you will. Place it on a strange orbit so that it clearly isn't the result of nature. Possibly make it a strange shape or color to strengthen the message. The message is that great beings came before you. Aspire to great things. [Answer] Pass it on to your children and make sure they understand the importance of passing it on to their own offspring - and try to be as convincing as you might. If future generations consider your message to be important enough, they will keep passing it on, and it will eventually enter "common sense/universal knowledge". If not, the message will eventually get lost (and probably for good reason). Your question implies that (you believe) any one of us (today) would have knowledge or advice to provide that will still be of relevance in 50,000 years from now. That may be so, but then they had already made it known to us. It were rather pointless to keep from us a message that "must" survive 50,000 years, but preserve it for future generations who might never be born. Any technical approach is rather useless, because it relies on the idea that what technology we know and use today will remain accessible for thousands of years. It doesn't matter which technical solution you opt for today, what really matters are the technical options future people will have to solve the riddles of their day. Physical devices, be they fancy gadgets or carved stones or books, may help your message survive physically (at least for a considerable while), but that doesn't mean your message's meaning will survival too. If anything, the religious scriptures we know today prove this flaw dramatically. What valuable message ever you may have for future generations, it won't make much sense without the proper historical context. [Answer] Well its a great Question, I think the best way to preserve a message for 50,000 years and also be understandable to the people is to make draft of useful information e.g rock carving,books,hard disks etc in large cylinders. Make many copies of it and bury some of them in sea, under the earth, below the polar ice, project them in space as a sattalite, send them on moon. someone in future will sure find it. [Answer] I would like to develop on the redundancy idea. I think the message should be not only redundant, but it's should be a sort of a physical RAID - a cross-referenced repeatable array of data. As for the storage medium, I do but think digital storage will cut it for 50 000 years. Contemporary digital storage is actually quite unreliable and decays quickly. Without constant attention and efforts to transfer it to new media the message will be lost quickly. Some answers propose disks and plates from exotic materials - I do not think that is going to cut it too. The storage medium should not be valuable by itself, nothing that future humans would like to melt, turn to jewelry or tools, etc. Rather it should be something comparatively worthless of itself, but durable and chemically stable. Fired clay tablets seem too be a very good variant, carvings on the cavern walls sound good too. So, returning to the topic of redundancy, I will speak on the example of the tablets. Each tablet is a separate page of your message, and should be explicitly marked as such. So that if a tablet in one storage facility is damaged, it should be easy to understand, which one should be substituted instead. Also, perhaps quite obviously, the tablets with the same parts of the message should be absolutely identical - the same number of rows, the same line separation, absolutely the same shape of letters and drawings (if there are any). Obviously, each storage facility should also have maps pointing to all the other facilities. As for the language problem - the Rosetta Stone approach seems the only one to go. Most likely, the tablet should have text in several languages running in parallel. I do not think whether there is any optimal way to select the languages - there is absolutely no way to predict the evolution of languages for time period that big. I would choose languages with drastically different writing systems, just to avoid confusion between languages. If possible, if the message itself is comparatively short, but decent amount of space can be devoted to storage, the message can include a sort of ABC - tablets with a single drawing and corresponding words in all the language for the most basic and important concepts. [Answer] Leaving aside the problem of actually deciphering the message in 50,000 years, there is one storage medium that is almost guaranteed to make it. # Say it with diamonds. > > Most natural diamonds have ages between 1 billion and 3.5 billion years. > > > Diamond is possibly the most chemically and physically stable material we know. Most natural diamonds were created before humans existed, and will likely be around long after we're gone. Sub-surface laser engraving allows the creation of internal engraving in a diamond. This is hard, but there are [companies that do it today](https://www.opsydia.com). Artificial diamonds are cheap. (Really cheap). Thus: 1. Get yourself a truckload of artificial diamonds 2. Engrave the message below the surface with sub-surface laser engraving. 3. Sprinkle liberally The message is very likely to survive in extremely inhospitable conditions. The only issue is high-temperature fire, which will cause diamonds to burn. this should be covered with redundancy and choosing good locations for your diamond messages. Diamond's desirability to humans, especially when cut and polished, is likely to remain for a very long time. Human fascination with gems has existed as long as we have been able to produce them, I think it's fair to say that it will continue long into our future. Making the message intrinsically desirable, precious and worth preserving will help it navigate the next 50000 years of human history. Leaving large piles of cut and polished gems in out of the way places around the world will likely ensure that some caches remain in 50,000 years. You can always use Quartz instead, [as is being done right now](https://en.wikipedia.org/wiki/5D_optical_data_storage) but really, where is your sense of poetry? ## Build a stellar clock I'd also recommend placing the message in multiple satellites with different decaying orbits. Ensure that every 25 years or so, a new satellite makes it to the surface, with a copy of the message, on the aforementioned diamonds, and instructions to await a second message. That would require a ~2000 satellite constellation, which is a reasonable number. Having a regular event, that occurs within human lifetimes, and leads to the message being (re)discovered, would also ensure that the problem of language is solved, as it is likely that the new message would be translated every arrival. This narrative of a message from the sky being delivered every 25 years would also likely survive extremes of cultural changes. Such cosmological events as comets or asteroids have been remarked on since we were able to remark on them at all. It's a bonus point that the satellites will likely be visible to the eye and telescope, especially if deliberately coated in reflective material, which means that their orbits can be tracked and their decay predicted, even if we have to re-invent orbital mechanics to do it. Increase the delivery rate and redundancy to improve the likelihood the message will persist. It's quite conceivable that you could have a yearly programmed orbit decay for 50,000 satellites. (compare this number to the total number of satellites we've sent up so far which is ~8900). The stellar clock mechanism has the advantage of being very resilient to cultural changes, while at the same time creating an intrinsic cultural focus for any civilisation. Think Halley's comet, except it happens more often and something falls to earth in a pillar of flame. I doubt many civilisations would miss the hint that something is going on. Risks are that gravitational disturbances would cause the clock to go off sync, although it's unlikely to change the mechanism entirely, it just means that the periods may be perturbed. Bonus if you call your constellation "Lucy" For one massive, 50,000 years Beatles song joke. **Reality check:** This assumes that the [Lyapunov time](https://en.wikipedia.org/wiki/Lyapunov_time) of earth-orbiting is greater than 50000 years, which [may not be the case at all, although it strongly depends on the orbit specifics](https://arxiv.org/pdf/1606.04180.pdf), in which case it's a pretty idea but not really viable. ## Build a foundation Isaac Asimov's [Foundation Series](https://en.wikipedia.org/wiki/Foundation_series) is predicated on this exact problem, and how Harry Seldon solves it. I'll let Asimov explain this more eloquently than I could in his books :) [Answer] 2 methods come to mind; 1. **Quartz memory discs.** They are a are currently existing technology that will store information for close to 12 billion years! - The problem? Designing a reader or instructions for building a reader that will last as long. 2. **Carve/mark giant symbols on the moons surface** pointing to a secure storage facility there containing information engraved on metal tablets or some other system that can survive being buried in a underground chamber in a vacuum for the period required. - The problem? Getting there to recover the info. [Answer] Now we can send a sattelite to a high and stable orbit, that can fly here for 50k years. If orbit is quite high, satellite will not be stopped by Earth atmoshpere, and it can orbit Earth forever. We can add solar panels and radio signals emitting beacon to satellite, so it can be found [Answer] Carve it into extremely hard rock, encase that in Lucite, and put it on the surface of the moon. Unless hit by a meteor, it should last millions of years. Look at Nazca...they scratch some line in the soil, and they're still stumping modern man after? ...an unknown number of years. The reliefs carved in Egyptian obelisks are still sharp, after ??? an unknown number of years, so any deep etching in granite or andesite would last. Or carve it into porcelain...that's supposed to last many eons...or encase it in our most durable plastic, and place it in orbit. If something doesn't have erosion to deal with (water or air/dust storms), images will last indefinitely. Look at the stones from Puma Punko, Teohaunico, or Sacsayhaunan...unknown age, still sharp and precise, and subjected to erosion...? [Answer] There is a technique that might be interesting and not "far future" (currently we can only show a proof of concept, we have not tested it, but it's not far of the "self driving cars" future). The bigger problem with a message that needs to outlive ourselves is that it needs to "stay alive": as in, it needs to not be destroyed. To stay alive we can quite literary just do that: either make a robot that is self replicating and intelligent enough that it knows how gather supplies to make multiple copies of itself which. Or even simpler: encode the message as a DNA sequence into the DNA of some species, many virii actually carry "information" about our history this way. And if you can encode it into a strong bacteria like the cyano bacteria it's probably going to last for a 100s of million years. [Answer] This expands on <https://worldbuilding.stackexchange.com/a/3433/2700> "Redundancy", but I felt it too large to be a suggested edit. ## Not thousands of copies: millions, or even billions. You know why we can still find dinosaur bones? Yes, bones are kinda durable, some chemical properties etc. But the fact of the matter is, there were many dinosaurs, and the ones we find, are the tinyiest fraction of a faction that happened by chance to endup somewhere that preserves them well. For super long-term storage you are targetting are the archeologists. They are the people with the interest and expertise to recover and translate the messages. * Print it in a book + send it to every library, archive and museum etc in the world + This is where future archeologists are going to start looking for information. + Some will (sooner or later) destroy it; but some small fraction will maintain it as they preserve other things in their collection. * Print it on microfilm, and burn it to CD, and any other compact media + run a publicity campaign asking people to try and store it, e.g. in household time capsules. + Send it to everyone who asks * get it digital, and try to get a copy onto every device + A virus would be effective in the short term, but would likely turn public sentiment against you. + Something like having a free copy of it included in every ebook reader (ebook app) would be good. + Having it be used as the secure erase overwriting data common OS system/security suite would result in it being on millions of thrown out government and corporate computers * Do everything else in this thread, not once, not a dozen times or a a hundred times but as many times as possible. Sure all these things have a a very finite life span, but they are really easy to do. All you are trying to do is get lucky. You are buying 1 million lotto tickets. [Answer] Ancient hominids managed to leave messages for longer periods of time. Evidently from this we can gather that the best way to leave a message, is leaving it more than once and more than in one place in different forms. We know about their religions, their social structures, we know about their families, their conflicts, those are all message they left and the rest we know from archeologists. [Answer] **Just pass it through generation as you would any other scientific information.** Wiki mentions that the problem is: > > Unfortunately, there is no method available to continuously provide > the necessary knowledge about the location of nuclear waste over > thousands of years. The culture of earlier centuries becomes > incomprehensible when it is not translated into new languages every > few generations. National institutions do not exist longer than a few > hundred years. Even religions are not older than a few millennia and > do not typically hand down scientific knowledge. > <https://en.wikipedia.org/wiki/Human_Interference_Task_Force> > > > But this is nonsense because people who call this "a problem" seem to focus on what they perceive as "important" - i.e. religion, which is inherently subjective and open for interpretation, and thus easily "mutated" with each generation, while scientific knowledge stating objective facts survived longer lengths of time undamaged. Statements of Pythagorean theorem or Archimedes' principle, for example, is about 2500 years old. **There's NO problem.** [Answer] You pack it into a lightouse made of diamond, in orbit, powered by the sun. The message is beamed out as laser, towards any planet that can host life (astronomy allows to compute those even today) and send your message in bursts. On some remote world, a disc of light reaces with the speed of planetary rotation + planetmovement, across the sky. ]
[Question] [ Dragons are a grand classic of fantasy. For this question, let's assume we're talking about the following stereotype: * hatches from an ostrich-sized egg and can grow to mountain size if nothing limits its growth (enough food and space) * lizard-like appearance, bat-like wings, able to fly * breathes fire * carnivorous With earth-like biology (or with believable variations), how close can we get to this dragon? Explanations are especially needed for: * fire breathing: how does it work? how did it happen through evolution? how does it impact the nutrition requirements (if gas is produced in high quantity, surely there is an impact there)? how is it not deadly for the dragon itself? * flying: is the energy requirement believable (even with heavy fire-resistant scales)? how much can the body look like a komodo dragon without it being an aerodynamics issue? And any other issue you can come up with ;-) [Answer] **Growth / size** The main argument against mountain-sized dragons is the [square/cube law](http://en.wikipedia.org/wiki/Square-cube_law). As an animal increases in size in its linear dimensions, but retains roughly the same proportions, its surface area and strength increases proportional to the square of its length, but its mass increases proportional to the cube of its length. To give an example of this, compare a mouse with an elephant. A mouse has relatively slender legs, while an elephant has thick legs necessary to support its weight. An insect is an even more extreme example of low size - they can have very thin legs compared to their bodies. Taking the example of increased size to the logical extreme, if an animal was to continue growing, it would eventually become so heavy that it would no longer be strong enough to move itself, and/or its bones would break under its own weight. The point at which this occurs depends on the strength and mass of the creature's body. Obviously, if stronger, lighter materials than those found in terrestrial animals were in use, the animal could grow larger. As the question specifies, using earth-like biology and conditions, the upper limit of size for a land animal would be on the order of tens of tons, certainly not more than a hundred tons. **Flight** The ability of a creature to fly is also dependent on the square/cube law. Larger creatures just don't fly as well as smaller ones. In an earthlike environment, the best fliers are no more than about a kilogram in weight, and flying creatures become progressively more clumsy as they get bigger. There is a school of thought that a non-magical dragon could lighten its body with hydrogen gas trapped in large pockets within its body to the point that it could fly despite its apparent large size, however this would result in a dragon as fragile as any bird capable of flight. Another school of thought is that *young* dragons fly in order to disperse themselves from their parents, since a carnivore weighing several tons would eat a whole lot, and lose their ability to fly as they grow. An adult dragon may retain wings, but use them for display, not flight. **Breathing fire** As to breathing fire, this could be explained with the example of the bombardier beetle. These beetles can produce a chemical reaction in their abdomens that is sufficiently energetic that the reaction byproducts are literally boiling, and it directs this from a nozzle at the end of its abdomen toward attackers. Breathing fire is a logical extension of this sort of ability. A dragon could produce and store a volatile high-energy fuel, or a liquid fuel with even more energy, and ignite it in many different ways, such as chemically-produced heat, or an electric arc. By squirting the fuel out fast enough from a duct venting into the mouth as the dragon exhales, it need not ever come into contact with the burning fuel. (Think spraying the flammable gas from a spray can over a cigarette lighter - it doesn't melt the plastic nozzle.) With a change in biology so that a dragon could precipitate metals such as aluminium or magnesium, a dragon might even be able to spit a liquid mixture akin to thermite that would spontaneously combust due to the presence of other reactants. Or, as Anne McCafferey proposed in the Pern series, exposing certain rocks to acids produces spontaneously-flammable phosphine gas. The main problem with fire-breathing is the amount of energy required to produce the reactants. Whether the dragon itself or some symbiotic organism produces the reactant, it takes an input of at least as much energy to produce the fuel as the release of energy when the fuel combusts. The best solution is if the energy comes from outside, as is the case with Anne McCafferey's Pernese dragons. **Fireproof** The point of "breathing" fire in the manner I have suggested means that for the most part, a dragon need not actually be *too* fireproof, since like a human fire-eater, the fire is not *inside* the dragon. On the other hand, a certain degree of heat resistance *would* be useful for a creature that could make a mistake with its own fire - or get into a fight with another creature that also produces fire. There are a number of adaptations that could help a creature that must maintain a relatively low body temperature deal with extremes of heat. 1. Some organisms, known as extremophiles, are known to live and grow in temperatures below freezing and above boiling point, achieving this through specialized proteins. Some desert living mammals, whose normal body temperature is 37°C, can survive a body temperature up to 50°C, whereas humans start having problems with hyperthermia at 42°C or less. It is not beyond the bounds of possibility that a dragon could have evolved proteins that allow it to survive much higher than normal body temperatures, perhaps well beyond 50°C, though most likely *not* over boiling point. 2. Where parts of animals bodies experience extremes of temperature, counter-current heat exchange mechanisms in their blood vessels greatly reduces the flow of heat to or from the extremities exposed to those temperatures. By selectively passing blood through countercurrent heat exchangers or not, peripherals can be maintained at a higher or lower temperature than the body core. 3. Carbon (which is in relatively abundant supply in carbon-based organisms) in the form of nanotubes or sheets has very high thermal conductivity. By strategic placement of such materials, the heating effect of point heat sources could be spread over a wider area and even transmitted rapidly deeper into the body, preventing burns by allowing an overall, but lower, increase in body temperature. Such materials also have the added bonus of being very strong. It is not beyond the bounds of possibility that a dragon may have evolved to be able to produce such substances. 4. By maintaining a high body mass, an organism which uses water as a solute for its metabolism would require a great amount of heat to raise its body temperature significantly - water has amongst the highest heat capacities of any substance per unit mass. 5. Creatures whose body temperatures rise higher than normal must eliminate heat, by radiation and/or evaporation. Having a large pair of wings gives a dragon a large surface area through which it can radiate and evaporate excess heat, and its large mass gives it plenty of water that it can evaporate to shed the large amounts of heat that may be involved. The combination of all these factors may result in a creature that, at its adult size, could be trapped in a burning wooden building for quite some time before it was particularly inconvenienced by excess heat, possibly on the order of some minutes to a quarter hour or so before its body temperature rose to a point that threatened its life. If it escaped such a situation alive, it could then shed the excess heat quite quickly. **Carnivorous** A carnivorous lifestyle is the most likely thing about a dragon. Carnivores obtain their energy far faster than herbivores, though they do have to work harder to catch their food. Herbivores can't afford to stop chewing for long, but carnivores (such as cats) can have a relatively quick meal and then sleep the rest of the day. [Answer] Anything is possible. EDIT INFO: Ok, after a bit of research I'm changing some of my answer. I'll leave the original parts underneath the new parts, if some part was majorly edited. Most of the new information came from [this](http://discovermagazine.com/2013/dec/20-how-to-explain-your-dragon) Discovery Magazine article. ### Fireproofness Scales would be made out of bone. They would be made out of practically solid compact bone, unlike the ones in our body. This would give them the strength needed, without adding an unreasonable amount of weight. These scales also would not burn, unlike normal reptile scales. I think a dragon that could withstand very high temperatures (Ex. swimming in lava), isn't possible under earth-like biology. Most standard internal organs need a pretty constant internal temperature. But with a well insulated skin (lots of fat), and fire-proof scales, a dragon could probably withstand what fire he causes. ### Growth Your dragons size is very interesting, growing all the way from a small creature to as big as mountain. At first this may seem fairly fantastical, but it isn't too bad. The dinosaurs did practically the same thing. So I think we can say that this is possible, and has even be seen in real earth biology. ### Flight Wings are easy, it is not hard to imagine a reptile with wings. They even existed in the form of Pterosaur. They would be controlled with muscles within the breast of the beast, likely any other winged creature. The main problem of dragon flight is that they are just too big. To get enough lift for the massive creatures would make the wings too unwieldy. But it is possible that they could still fly. The dragon's bones would be hollow, like both birds and dinosaurs were. but instead of being filled with air, their bones would be filled with lighter than air gases such as hydrogen, helium, or, most likely, methane, which is a byproduct of flatulence. The dragon's body would also be filled with large sacs filed with these gases as well. This would also make dragons more agile, because they would be easily light on their feet. This would also mean they could look pretty much like anything, because aerodynamics is no longer in effect. ### Firebreathing This idea specifically comes from the discovery magazine article listed above. Dragons would have two sacs with holes that enter to their mouths. Inside one sack live organisms (like yeast) that produce ethanol. Inside the other lives bacteria that produce sulfuric acid. These two gases are allowed to mix inside the dragon's mouth, just before it breathes fire. The chemical that is produced when these two mix is Diethyl ether, which is highly flammable. The tiniest amount of friction can light it (spilling a beaker on a table is capable of lighting it). The dragon would have to not inhale while this was going on (this would of course be an involuntary reflex). As the scientist who was interviewed in the article above points out, we don't always know how something evolved. But similarly complex defense systems have evolved on earth (the bombardier beetle is an example). A guess as how the sacs are formed is given below. --- The original purpose of the two "sacs" was a very simple, an ineffective, breathing mechanism. These sacs were criss-crossed with blood vessels and bones, leftover from gills, and used for the first mechanisms of breathing. As a better breathing system (lungs) developed, the sacs fell out of use, and bacteria and yeast took over them. These then began producing the above substances to create fire. --- EDIT: The next too sections are outdated but kinda fun, so I left them here. This is another technical possibility of fire breathing This idea comes from the *How to Train Your Dragon* books. All dragons could have two holes in there mouth, these holes would excrete a highly flammable gas during exhaling, this gas is then breathed out of the mouth. At the edge of the mouth, there would be an instrument (likely two special teeth) that when rubbed together would produce a spark. When the spark hit the gas, it would light, creating a plume of fire. This gas would be hydrogen, made from splitting the water molecules made from splitting glucose. This would not have a significant impact on the dragons energy levels, because it would use the energy made from the glucose to split the water. The carbon-dioxide made from the split would be exhaled as normal, and the oxygen would be released with the hydrogen to increase the flammability of it. (One hole releases hydrogen, the other hole releases oxygen). Both gases are stored in special sacks behind the holes. To protect against the mouth being burned, the front part of the inside of the mouth would also be covered in scales. No essential organs (not even the nose) would be housed near the front of the mouth. However, if the gas was somehow blown back down the dragons throat, it could be killed that way. --- Next up, evolution of fire breathing. Michael Kjörling kindly asked how this would be possible. The original purpose of the two "sacs" was a very simple, an ineffective, breathing mechanism. These sacs were criss-crossed with blood vessels and bones, leftover from gills, and used for the first mechanisms of breathing. As a better breathing system (lungs) developed, the sacs fell out of use, but occasionally unused hydrogen, oxygen, and carbon-dioxide still ended up in them. These two gases would leak into the mouth of the dragon as the sacs opened and closed. The sacs would open when the mouth of the dragon opened, and close when it closed. These dragons ate a high iron content. As dragons developed some teeth began to have a higher and higher content of iron in them. These teeth were stronger, and could break more things. At one point, a chance mutation caused two teeth to be angled in such a way that they would cause a spark. This would then cause the mixture of hydrogen and oxygen in the mouth to ignite, and the process described above would happen. ### Energy A dragon would use a massive amount of energy. But so did dinosaurs. A dragon would have to eat a large amount of food, but that would be possible. Especially if dragons laid and wait and did nothing for much of the time. Then they would eat only occasionally, and then in large amounts as there prey would be unprepared. The cost of flying wouldn't be much higher than that of a bird because of the lighter than air bones/sacs. Fireproof scales are just standard bone, and would not be that energy consumptive to create. Breathing fire costs little energy, because it is done by using the work symbiotic creatures. --- Finally, don't argue. [Dragons don't like it](http://ffn.nodwick.com/?p=1305). If that didn't convince, read the [ending](http://ffn.nodwick.com/?p=1304). [Answer] I could hardly beat the great level of detail in the other answers, but I like dragons a lot and I think I can share my relevant knowledge with you. ### Hatching and Growing I would assume a dragon would be quite similar to the dinosaurs or the creatures that represent the evolutionary phase between reptiles and birds (like the Archeopterix), based on the popular representations in folklore tales and fantasy stories. Egg hatching then would be the way of reproduction. The growing can depend on many factors, but in most cases it is determined primarily by the DNA. An interesting case (aside from the topic) is a [Liger](http://en.wikipedia.org/wiki/Liger), that is a hybrid produced of a male lion and a female tiger. It is the biggest cat in the world and for a reason - the genes for growth reduction are carried by the male tiger for the tiger specie and by the female lion for the lions specie respectively. Thus a liger has no genes for resticting his growth and so it *was believed*1 to grow all his life, becomming the largest cat in the world. If dragons were not a regular specie, but produced as a hybrid betweeen species so that it happens to lack growth restriction genes, or if their DNA did not have the growth restriction for other reasons, then a dragon could grow in size troughout his life. ### Flight Flight is a very energy intensive task and has a lot of requirements for the body structure, mass and size in general. Thus, it would eventually contradict with the first point of near-limitless growth. We could still assume a dragon is similar to a bird-like reptile, or a pterodactyle, it would grow large enough and still be able to fly. If growing continues to a certain point, it is possible the dragon reaches size and mass that would not allow him to fly. Since then, a dragon could adapt and lead a life similar to the non-winged dinosaurs and the other ground predators. ### Breathing Fire Breathing fire, literally, is something that I personally would not believe. However, since this characteristic is taken from foklore tales, we could assume these are either exaggerated descriptions of a real capability, or otherwise twisted by the story retelling. Still, I would associate this ability with the description of the [Komodo Dragon](http://en.wikipedia.org/wiki/Komodo_dragon), which is a large lizzard of the Varanidae family. These lizzards are known both for their large sizes and "poisonous" saliva. Their saliva is not really poisonous, but it has special bacteria which causes the decay of any exposed flesh. The exposure wounds similar to burns of acid, and these could have been attributed to a "breath of fire" by our uneducated ancestors. I watched a BBC show a long time ago (I am unable to recall the name), which also supported this thesis, and added some ancient cultures drawings as a proof - the drawings were of large Varanidae-like lizzards breathing fire. (It is still uncertain if these would rather contribute to the "fire lizzard" folklore specie, insted of supporting the dragon existence, however) ### Carnivous If the creature is indeed derived from a dinosaurus, or is a reptile-bird specimen, then it could share the same need for energy we already know these species have (dinos were large and ate a lot, burds need great amounts of energy to fly and lead quite a dynamic way of life). Definitely, a dragon would be a mobile creature with active lifestyle (able to fly), which requires a lot of energy. It makes sense that the dragon would more than often predate on large and potent prey in order to support its existence. In addition, it could also have evolved the ability to go into a lethargic state, like some mammals and reptiles do if the time of the year is not suitable for frequent feeding. In some folklore tales, and modern fantasy stories, dragons are often being "awakened" from years of sleep by the story's main character. I hope I was helpful. --- 1 The Liger was believed to grow trougout his life, due to the explained above genetics. This statement was based on outdated information I had on the topic. However, newer information regarding this hybrid specie does not support the lifetime growth ability (refer to wikipedia article and [Tim B's comment below](https://worldbuilding.stackexchange.com/questions/313/how-could-dragons-be-explained-without-magic/350#comment588_350)). The misbelief was further supported by the characteristics of the other lion/tiger hybrid - the Tigon, that is created by a male tiger and female lion. The tigon retains smaller sizes in comparison to both his parent species, due to having both lion and tiger growth restriction genes. [Answer] **FIRE BREATHING** Well, fire-breathing without burning yourself is obviously possible. In addition to various systems already proposed with binary compounds, I'd like to point out that you could have self-igniting saliva that includes a stabilizing compounds. This IIRC is the method many poisonous snakes use with their poison. They simply secrete the anti-dote together with the poison and it will protect them from incidental exposure, but when the venom is "used properly" the protection will fall short and the target will be poisoned. As the saliva glands -> venom glands path is the logical pathway for the evolution of fire-breathing reptile this would be the proper starting point IMHO. Poison could be initially an irritant, evolve to being corrosive (ants have acid for example), and if the corrosive is oxidative that is short path to making things burn. It would likely be a mixture of several oxidizers and matching stabilizers. Oxidizers would probably mostly be based on oxygen from the air. Chlorine might be easy enough to get near the ocean. Fluorine would be kind of neat to add, but I am not sure if there is a convenient source. As a practical matter the stabilizers would probably be something that is rapidly vaporized. Inside the dragon it would be continuously replenished, but as soon as the "fire-breathing" started the chemical balance would break almost instantly. Some fuel beyond the methane from breathing would probably be also mixed in. Some mixture of alcohols and fat, I'd guess. To give pleasant clinging effect when breathing on someone. And give a higher temperature to get fires started. And cause serious burns even if the target doesn't ignite. Although a strong oxidizer would make most organic things burn well enough. The probable evolution path would be from a spitting venom, initially targeted at eyes. Then mating rituals. So it would be flashy and mostly cause damage to exposed parts. On targets of reasonable size. If the dragon is much larger than the target, as implied by the question, it would be a lethal weapon. In the real world the above would kind of imply evolution from snakes as most likely option. I'd actually go with that as snakes re-evolving legs would neatly sidestep issues with six being a wrong number of limbs and allow 2 wings plus 4 legs or 6 legs configurations. **FLYING** The big issue with dragons, especially when combined with flying, is obviously the size. Realistically the issue has been solved by engineers with either high-energy power generation (airplanes and helicopters) or by making the aircraft float in the air with lifting gas. Since the physical problem to solve is the same these would be the solutions available to draconic (non-magical) evolution as well. I find the concept of fire-breathing animals, probably commonly fighting each other, being filled with hydrogen less than convincing. Helium would work, but the only sources for it would be ingesting large amounts of methane (methanovore?) or radioactive generation. Tapping underground methane would actually be kind of interesting, as it would explain why dragons spend centuries in underground caverns doing nothing visible to humans. They are breathing in the methane, living from the energy of it and harvesting mixed in helium. Actually eating methane might be a draconic attribute even if you skip dragon-blimps. Apart from matching the iconic behaviour of dracons, a source of methane is useful to fire-breathing. Third lifting gas option would be hot gas, either plain air or steam. This might actually work for a VERY large animal. And needing to generate high temperatures would match with evolving other pyrotechnics. Problem is that dragon-blimps don't really look very dragonic. So I think I'd skip this option and focus on increasing power density. I think the easiest way to up power density would be to increase the number of hearts. Basically biological power density is limited by the ability to remove heat and metabolites from tissue. You also need to bring energy in, but that is not generally the issue when talking about power density. This kind of implies that dragons would be able to boost their metabolic rate to level insane. Which would imply very high blood pressure at muscular system, while other parts, such as brain, maintain normal pressures. And one heart maintaining high pressure at a very large animal wouldn't really work that well anyway. Separate secondary circulation systems that boost pressure selectively might work. By itself this wouldn't be enough, but if you can increase blood pressure, and maybe even have an entirely separate circulation of "something else" with higher power density, you can also replace muscle cells with something else. You can't really make cells work with power beyond certain level, but cells could generate structures capable of higher power in a manner similar to how hair is created. I have no idea how high this could get the power density, but high enough that power density wouldn't be the biggest issue... So you end up with the structural strength being the big issue. Hollow or otherwise low density bones are pretty much compulsory. Even then you'd probably need "biologically generated but not living" structures such as I used to dodge the power density issue. Nature has some remarkably strong protein based fibers and glues, so composite structure of fibers combined with strong adhesive seems likely. Something similar to what trees use with cellulose and lignin? Trees can grow to large sizes and protein based solution would plausibly be stronger. Supplemented with similarly reinforced "semi-exoskeleton" of powerful natural armor (very dragonic) and the high density muscles discussed before, this might be enough. Certainly you could get something larger than any living dinosaurs. Breathing enough oxygen would still be an issue. Dinosaurs and birds have more efficient lungs than mammals do but still. If we assume that the fire comes from a powerful oxidant, the dragon might be capable of storing large amounts of the oxidant and use that oxygen to power up. Or possibly the "new muscles" required anyway, don't consume oxygen directly but work more like a plug-in hybrid does. Dragon sleeps and charges the batteries for the muscles and then the muscles can do a specific amount work without extra metabolism needed beyond the secondary circulation for cooling and energy. I can see how the exotic bones and hide would evolve naturally as sizes go up. Reinforced structure is useful in intermediate forms and based on natural proteins. Same with extra hearts. Extra control of blood pressure in extremities is useful in intermediate forms for large animals. Evolution for exotic muscles is harder... Then again if we assume a snake re-evolved limbs and already assume an unusual configuration, the exotic muscles might not be evolved from normal muscle to begin with. Which doesn't really suggest how they evolved, but opens up the possibilities enough for the lack of explanation to be less bothersome. Sorry, for rambling, but this is actually something I have though occasionally about... [Answer] Growing from a very small size to an extremely large size is no problem, as dinosaurs show (and remember, ultimately even the largest dinosaur started as a single cell; the size of the egg is basically about how much initial nutrients are stored for the organism until it is ready to get out of the egg). I don't think you could get literally to mountain size, but if taking that as hyperbole, I'd say that [12 meters of length for T. Rex](https://en.wikipedia.org/wiki/Tyrannosaurus) is already a very impressive size (and at least in the fantasy with dragons I've read, which admittedly is not very much, the dragons weren't much larger). Now flying could be a problem with large sizes. However a [Quetzalcoatlus](https://en.wikipedia.org/wiki/Quetzalcoatlus) was still of impressive size. Bat-like wings should probably not be a problem. Whether a lizard-like appearance would be realistic probably depends on how exactly you define "lizard-like". There would probably be some shape requirements for aerodynamic reasons. But otherwise I see no reason why this should not be possible. The most problematic point, of course, is breathing fire. As far as I know, there's no known animal that does or did that. However, we know that inflammable substances (alcohol!) can be produced by organisms, and we know that in principle it should be possible to safely emit fire (every fire-eater shows this). The main problem would be how to ignite the breath (in a way not to harm the dragon itself). However, I guess that should be a solvable problem; there could be for example some substances which the dragon could emit in small amount together with the inflammable gas or aerosol, which has a strong exothermic reaction in air, thus igniting the gas. Maybe there's a chemist here to tell whether that would be possible/feasible. As Michael Kjörling mentions in the comments, a substance that inflames in air would be hard to contain, and thus very unlikely to evolve, therefore a better solution would be a two-component ignition, where each substance in isolation is harmless, but when they meet they ignite. If the substances have a use also in isolation, this is more likely to evolve, and it is not unrealistic that at some time a mutation caused them to be emitted at the same time, giving the ability to breathe fire. [Answer] I think most of the answers focus on bringing dragons to humans. I argue the opposite would be easier to do scientifically. Modify the world to support dragons, then bring humans in as otherworldly visitors in advanced habitat modules and pressure suits. I'm not sure how to make the humans appear medieval in that circumstance, but the question didn't request the usual fantasy backdrop. Nor was any implication made that humans must be comfortably habitable. Perhaps the dragons exist in a thick atmosphere which is highly combustible with the addition of some biologically inert catalyst. The dragons could fly with their large masses due to the thick atmosphere, although it would lead to higher atmospheric pressures. The chemistry of the air and the biologically inert catalyst are beyond me. A small spark could come from high concentrations of iron in the teeth and tongue. Calcium is pretty reactive in its elemental form; maybe the reaction of the dragon's saliva with its teeth creates a small flash. The saliva would be like snake venom, contained in sacs. That'd cause a lot of tooth decay. Add shark teeth growth so the teeth are replaced. [Answer] Hmm, seems to me that it's pretty obvious that dragon-like creatures are biologically possible, because we know that they used to exist. We call them dinosaurs. "Grow to the size of a mountain" is pushing it, but some dinosaurs certainly got very big. Big enough that a person might describe them as "the size of a mountain". "Lizard-like appearance." Yes. Reptilian, anyway. "Able to fly." Well, you run into a square/cube problem if you want a very large creature to fly: The mass of a creature increases with the cube of it's size, but the surface area of its wings only increases with the square. As lift depends on wing size, in practice it appears that living creatures, at least those using the sort of biological processes that we are familiar with, run into a limit here. Among real dinosaurs and dinosaur-like creatures, there were some that were very large, like diplodocus, and others that were able to fly, like pterodactyls. But none that were both very large and able to fly. "Breathes fire." First we should ask exactly what that means. Do we mean specifically something like the fantasy picture of a dragon, spitting flame out of it's mouth like a huge flamethrower? There's no creature alive today that does anything like that. Though of course that doesn't prove it's impossible. There are creatures like the bombardier beetle, that sprays a combination of chemicals out its rear that makes a little explosion. Beetles are tiny, but if you scaled up the quantities of chemical, it might make a nice little explosion that could be called "breathing fire". In any case, it demonstrates that the principle is not impossible, but in fact exists in a creature that we can observe today. The bombardier beetle has a complex collection of chemicals that enable it to spit out this little explosion without blowing itself up or setting itself on fire. It doesn't seem implausible that a different combination of chemicals on a larger scale could make a more "impressive" fire. [Answer] If you increase the oxygen content of the atmosphere and make it more dense (as some scientists believe the earth once had), then you can allow for both larger land creatures as well as greater buoyancy for flight. It would also make it much easier for any flammable gases produced by the dragon's gut (say, methane) to catch fire. [Answer] Just a note on fire. I was reading through the other answers and I was really impressed with the idea of fire-breathing being biologically possible with chemicals. Has anyone considered something like a biological binary compound to create fire? For example: Gland A creates Agent A. Gland B creates Agent B. Dragon shoots a compressed mixture of Agent A, then Quickly shoots a second puff of Agent B. When Agent A and Agent B mix, they instantly react with oxygen. POOF!~ [Answer] **Want to improve this post?** Provide detailed answers to this question, including citations and an explanation of why your answer is correct. Answers without enough detail may be edited or deleted. A fairly rational science fiction dragon model has actually been done already, Anne McCaffrey's *Dragonriders of Pern* series of books. Here's the Wikipedia link: [Dragonriders of Pern](http://en.wikipedia.org/wiki/Dragonriders_of_Pern) It's a good model to start from, and I think it's the best 'realistic' model I've seen. [Answer] In the future, when time machines are ubiquitous, send someone clueless (intern?) to late Triassic period to capture a sample of pterodactyls for research. Let intern set up wrong target date for transfer in the time machine so they get sent to Middle Ages instead. Ooops! Of course these "dragons" do not breathe flames. I do not think that there would be an evolutionary pressure for a flying predator to evolve fire breath - what it will be the use for it? One hint about it uselessness for predators is that it did not evolved in the nature. Flying predator's main advantage is speed and ambush, fire-breathing is for no use for such hunter. Some poisonous/smelly excretions are more often used as defense mechanism. My solution has 3 out of four requirements, and is 100% plausible (after invention of time machine of course). [Pterodactyls](http://en.wikipedia.org/wiki/Pterodactylus) and [other flying dinosaurs](http://www.livescience.com/24071-pterodactyl-pteranodon-flying-dinosaurs.html) do **not** resemble komodo dragons (which are reptiles, way too slow and inefficient to fly). Science suspect these were warm-bloodied animals. But they do resemble dragons of lore :-) - even more than komodo dragon does, so... I read a story like that, but some people believe that it is a valid answer only if I pretend to imagined it myself, so forget about that story. Sorry I did not added links first, I thought that interested parties would know pterodactyl. Also, I do not know how to build a time machine, sorry it that is a problem for you. [Answer] Focusing on the fire breathing, I'll quote a bit of Heinlein: > > " (...) Eight feet high at the shoulders, a few tons each, and teeth as long as any forearm—all they need is to breathe flame" > > "Oh, but they do! Didn't I say?" > > I sighed. "No, you did not." > > "They don't exactly *breathe* fire. That would kill them. They hold their breaths while flaming. It's swamp gas—methane—from the digestive tract. It's a controlled belch, with a hypergolic effect from an enzyme secreted between the first and second rows of teeth. The gas bursts into flame on the way out." > > > *[Glory Road](http://books.google.nl/books?id=XvY2QP0XhlwC&lpg=PA176&dq=methane%20inauthor%3Aheinlein%20intitle%3A%22glory%20road%22&hl=nl&pg=PA160#v=onepage&q=methane%20inauthor:heinlein%20intitle:%22glory%20road%22&f=false)* by R. A. Heinlein > > > [Answer] Averting a little bit the classical representation of a european dragon: what if it's not a giant "Smaug" type creature that breathes actual fire but an actual living creature stories about which are greatly exaggerated. 1. Wyvern type body structure akin to the flying reptiles from our world or maybe more on the [fantasy side](https://www.google.ru/search?q=wyvern&newwindow=1&biw=1600&bih=799&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjZ04XkprnOAhVqP5oKHb85BA8Q_AUIBigB) given right planet surface conditions. This eliminates the problem with an extra set of paired limbs. 2. The size is not so giant, more like the biggest flying birds or reptiles that are or had been in our world in given environtmental conditions. Think of the ~2.5-3.5m wing span. 3. It lives in grass planes or savannahs and hunts mostly on grazing animals of small to medium size and on small mamals that live in borrows(rodents, rabbits and meerkats) while it's young and small. 4. The "fire breath" is not actual fire as it's difficult to explain the evolutionary need for it or any of the intermediate steps that would lead to it but a liquid toxin that evaporates rapidly and may be acidic based thus leaving "burns" on the affected skin. The toxin itself is more of a paralyzing/anesthetic substance like Chloroform as inhaling it cause the neural system to malefunction or even shutdown. To summ up: it's a big flying reptile that lives in planes and savannahs, hunts by suprisingly attacking its' prey from airbourne spitting the liquid toxin over it. The toxin starts to evaporate and inhalation of vapors leads to paralysis/coma/death through suffocation at which point the pursuing dragon comes down and easily finishes off the prey since it can't ressist anymore. The toxic breath may be also used to ward off scavengers(lions, hyenas, wolves etc) while the dragon consumes his prey or maybe those won't even be attracted to it due to the smell. While the dragon is juvenile it may hunt on smaller mammalians by exhaling its' toxin inside their burrows and tunnels forcing them to abandon it or die(since for their smaller bodies a smaller dosage of vapor would be enough) at which point it catches them or digs the corpses out. "smoking out" thing. Now if we introduce humans into its habitat it's likely that the dragon may attack a single individual or even a small group since volume wise humans are more or less the same as its usual prey and prior human arrival the dragon was the apex-predator of its biome. Those who survive will have burnings from it's breath which they may take for fire-inflicted burns due to the low levels of science. And of course the stories will be greatly exaggerated growing the creature from 3 meters to 15 and claiming that it can breathe fire so hot the metal melts(actually rapdidly rusts or acidizes losing the required properties in the process) and capable of buring entire un-exisiting villages - "true story, bro, I never lie: ask my mom." [Answer] The flying would be hard, because it is just not feasible to expect a dragon that is tons of pounds to be able to fly. UNLESS it's weight is less that it would seem. Extra gas, hydrogen would be most likely, would potentially be able to decrease the weight, but its debatable whether the minimum amount of organs needed to keep an animal that size alive would themselves be too much weight to fly. Fire breathing is easy. You could look at the Bombardier beetle and do something like that. This beetle creates an explosive gas in a chamber inside his body then expels in through holes in his abdomen. With only a slight few routing changes, that could be quite feasible. [Answer] <https://en.wikipedia.org/wiki/Chrysopelea> ![A Flying Snake](https://i.ytimg.com/vi/7AtghWoe1_E/maxresdefault.jpg) While you did say a "lizard-like" appearance I believe a more oriental eastern dragon would also fit your criteria. However, the flaring of the ribs could occur even in western dragons. Combine this with the natural balloon sacs and much larger wings mentioned by previous posters and, you have flight capable of dive bombing onto prey. Furthermore, a dragon does not have to be skilled at more graceful movements in the air as it: * will most likely be the biggest baddest thing in the air * will most likely eat large landed prey like deer. * could not be graceful like most birds at it's size to begin with (no barrel rolls for you today Mr. Dragon). [Answer] First I'll address fire-breathing The dragon could produce a very flammable liquid in a gland, and could spit it out, past the teeth. The dragon could click his teeth in a special way, producing a spark, lighting the gas on fire. The dragon could fly but the wingspan would be colossal. As for the fireproof scales, it's possible to, if they're thick enough and the skin underneath is totally protected. [Answer] Other people have already mostly covered this. I think flying is the biggest problem. The bones need to be elephant-strong but not elephant-heavy. If it's big and active it probably needs to eat a lot. The easiest stuff to eat a lot of is grass etc. It ferment carbs and cellulose in it's big fermenting stomachs, it must carry a lot of it for some time to get the fermentation, and that's heavy. So far it's a lot like a lizard-elephant. But it can produce methane and it can burp the methane, so all it needs is a way to ignite that, which other posters have considered solutions to. Possibly it could fart methane and light that too. Fire at both ends. Maybe it only flies when its stomachs are empty. If it really wants to fly it empties them? An empty elephant is probably a lot lighter than a full elephant.... Also, methane has a little lift but not much. [density of various gases](https://www.engineeringtoolbox.com/gas-density-d_158.html) Ammonia would be just about as good. Ammonia has a different flame and various other dangers. A dragon wouldn't necessarily evolve to use the gas with the best lift, it would use whatever the easiest evolutionary path led it to. [video with burning ammonia](https://nerdist.com/burning-ammonia-flows-like-a-river-of-hellfire/) As others said, hydrogen would be better. And the dragon doesn't have to look like a dragon after it empties its bowels of everything but hydrogen and flies. [what a flying dragon might look like](https://www.youtube.com/watch?v=u7QXdlSBGGY) [Answer] Historic references to dragons may be pertaining to dinosaurs that have survived the ages. Some people subscribe to this theory. It may sound outlandish in contrast to conventional education, but then technically, what is a crocodile? A crocodile is a dinosaur that survived through the ages. Ask any biologist. Ergo, it is not even outlandish to say that there may have been dinosaurs in the middle ages since there are still dinosaurs now. In fact, although unlikely, it's possible that dinosaurs still exist today, limited to some remote and uncharted area. Until humans emu-walk every square meter of land surface, and video tape every cubic meter of sea water, there is no definitive proof that every last dinosaur has died out. Now, how do you prove that there was never a kind of dinosaur that looks exactly like the imaginary dragons depicted in Hollywood movies? Failing to find fossils of it is not a proof of it never existing. My only concern would be whether dragon flight is bio-mechanically possible. I'm not qualified to comment on that. ]
[Question] [ I live in a world where magic is common. Most people have enough magic to do simple tasks like lighting a candle or healing minor injuries. Higher magic is very rare, and those individuals mostly devote their time to the study of magical arts and science. In the last 100 years, there have been great leaps of scientific progress, which have improved the lives of everyone. Most devices harness an individual's magic power to perform complex tasks through technology. The most recent innovation was short range teleportation. Magic includes elemental magic, healing, limited psychokinesis, barrier spells, and other staples of the magic arts. ## How it works: Basically everyone has a Magically Amplified Common Application Watch (Macaw). The teleportation function runs off the Macaw. I imagine a location or punch it into the holographic display, snap my fingers and I'm there. At locations a significant distance away (5 miles+) the landing location starts to get imprecise. Teleports over 20 miles are discouraged for safety reasons. There is a "cooldown" time of about 10 minutes after each teleport to allow a person's magic to recharge. ## Why it works: Don't ask me, I'm a shopkeeper not a scientist. I asked an arcanist about it one time and all I got was science talk and magic theory. Way over my head. From my extremely limited understanding, it takes the common magic that everyone has and twists it through certain techno-apparatuses. Despite only being able to light candles with my own magic, I can now teleport like a master wizard. People can teleport with any goods they are carrying or wearing. Somehow the Macaw makes reasonably accurate decisions about what is "on their person". ## The Problem: While this new-fangled teleportation is great for day to day activities, it's a nightmare for security. I run a small jewelry store in downtown Technistadt. I sell a lot of small, lightweight, but high-value items, perfect for a potential thief. **I want to be able to secure my items from a thief teleporting in and out of the shop while still remaining open for business**. Several stores have already been hit by smash-grab-teleport robberies, and it's just going to get worse as this technology becomes more common. Some options I've already considered: * I've talked to the Macaw manufacturers. They told me they are not only unable to prevent people teleporting to a certain place, but all teleports are also untraceable. Seems like a major design flaw if you ask me. * Teleportation will fail if the landing location is too small or otherwise unsafe. Not sure I can apply that to an open shop though. * [Some warehouse owner across town](https://worldbuilding.stackexchange.com/questions/38729/how-would-you-defend-a-package-from-magic-ninjas/38769#38769) swears by his robot watchmen and poison gas traps. Good for him and all, but I'm trying to run a shop here, not a bunker. Whatever security measure I decide on could be visible to my customers, but shouldn't impede my business. [Answer] How about hanging birds and mobiles from the ceiling - something that's easily pushed aside by a person when they're in the shop but it removes the spaces that can be easily teleported in to. [Answer] **Use your shop to display replicas of your jewels.** The easiest way to not have to worry about shoplifting is to not have anything to steal. Luckily, the MACAW offers an easy solution for this: simply keep all of your wares off-site and show your customers replicas of all of your jewels. Then, when a customer wants to purchase a jewel, you can simply have your assistant teleport in with the actual jewel for inspection and purchase. With a 10-minute cooldown, you'll likely want two assistants. Every ten minutes, one will teleport to your warehouse with a list of all of the jewels people are interested in as well as any jewels that need to be transported back to the warehouse for safekeeping, and the other will collect those jewels and teleport back. [Answer] Retractable floor. At night, the shopkeeper presses a small garage door open/close style button that retracts that floor leaving the show cases suspended over a 20 foot deep pit (read as 'your basement') filled with 4 foot deep pool of a tarry slimy substance that's covered in feathers. A few hangings can prevent people from teleporting ontop of the cases and instead fall into the pit below when they teleport in. Search for the criminal the next day by looking for a tarred and feathered thief. Filling the pool with red dye could create a more literal 'caught red handed' situation if you prefer. [Answer] If there is a 10 minute cool-down period, why do you have a security problem? They pop in, grab something, and...busted. Unless they are waiting around for 10 minutes and then popping out with said valuable. In this case the answer is simple - no MACAW devices are allowed in the store. You could probably pay a wizard or witch to cast a MACAW barrier to the entrance of the store, preventing the device from entering through normal means. If a MACAW pops in, your bouncers will be happy to collect the device and return it as the patron leaves. Bouncers are helpful like that. **EDIT** You are right to need evening security as well. Here you can either go standard and lock everything up in a vault or lock boxes - very cumbersome and expensive. A better bet would be to install a security system and an overnight sleeping spell. They get in, motion detectors alert the authorities and the sleeping spell keeps the perps right where they are. Arguably, you are building a "mouse trap", of sorts, but what is one to do in a magical society? [Answer] If a Macaw is able to precisely aim for a location *and* determine whether or not the user's dimensions can be accommodated, then it has a targeting sensor. If it has a targeting sensor, technological or magical, then it has a weakness, and someone would discover a way to fool it. Perhaps the device or application fools the sensor into thinking the space is full of hanging mobiles (or solid rock), perhaps it merely deflects the sensor to the perimeter, either way your Macaw won't deliver you to the desired location. As a side-effect this device or application fools Macaws in the room into thinking they are elsewhere (or nowhere at all), which has the effect of preventing *outbound* teleportation. Turn on the device, or coat an object with it, and you've made it invisible to the Macaw and therefore safe from teleportation. Now this may be beyond the abilities of a humble shopkeeper to come up with himself, but out there, somewhere, perhaps in a back-alley market, there is a solution to be purchased. [Answer] You know that annoying ink bomb (in our real world) that clothing stores sometimes forget to remove? Or those electronic tags that set off the door-alarms at Target? Attach those to your wares. I assume that with the technology of this world, there is something akin to wireless communications, like Wi-fi. (Otherwise, how would MACAWS parse location data? Surely there is a Google-Maps-esque Internet (or, MACAWnet) database for locations) Make the equivalent of ink bombs/electronic tags, that stay deactivated while connected to the Wi-fi in your store. When they're teleported out, they explode ink all over the thief/notify the police of the thief's location/etc. [Answer] Teleportation doesn't really change the nature of shop lifting. It is just a more effective method for what is currently accomplished by young legs and good running shoes. So do what we do in the real world... Shatter-proof (bullet-proof before there was bullets) glass cabinets. If the burglaries are all smash and grab, putting your products in floor-mounted smash-proof display cases will keep them from being grabbed. [Answer] ### In the day Attach every item in the store to a thin, very strong wire that's fixed to something larger and ultimately to the wall or the floor itself. Customers can examine the items, but the items will remain fixed to the wire. Here's what it looks like: [![enter image description here](https://i.stack.imgur.com/H3IZx.png)](https://i.stack.imgur.com/H3IZx.png) [Video: INOX Stainless Steel Jewelry Anti-Theft Ring Display](https://www.youtube.com/watch?v=Y9XVYvjviK0) I'm not sure exactly how the Macaw would handle an item that was both held by the user and fixed to the interior of the shop. Would the wire break? Would the whole wall teleport with the guy? Or would the item remain in the shop? I'm not sure, as I didn't invent the rules of this teleportation premise. But I think this wire is a feasible solution. The items should also be stored beneath tough, hardened glass or another transparent material. Customers have to ask if they want to examine some item more closely. The wire could be cut with the right tools but you or a security guard should be watching the customers while they handle the items. This is quite common in the real world. Salesmen don't just hand customers a Rolex and then let them wander off. It's normal to stay with customers while they examine expensive items (the salesman can also then give advice and assistance.) Thus, watching the customer, you'll have enough time to react if someone pulls out tools to try to cut the strong wires. There may also be an alarm sounding if a wire is cut. This means that even if a customer managed to stealthily cut a wire, they'd have to teleport out immediately, limiting their loot to one item. However, one single item can still be very valuable. Therefore, the most important thing is to watch the customers while they handle the items. The shop should also be under video surveillance. This means that even if anyone would happen to trick all your routines, they should still expect that a picture of their face will be forwarded to the police. ### In the night You lock up the shop just like any shop in the real world. This means you have 10 minutes to act on Macaw intruders. A normal burglary alarm can detect people having entered. The alarm is forwarded to your private residence, as well as to a private security firm and possibly even the police. You (together with private, armed security personnel and maybe the police) use your own Macaws to **teleport into the shop, catch the intruder** and confiscate his Macaw, well within the 10 minute window. [Answer] Your security budget and posture will drive a lot of this. One easy way to solve this is to have a safe, put all your valuables in the safe, and never allow any individual other than yourself to view the room containing the safe, or the interior of the safe. This prevents the 'must visualize' component of the MACAW from functioning. Your business would operate as many elite jewelers operate, whereby you emerge from a backroom to present the article for the customer's inspection. As it sounds like your sales volume may be a bit too high for this option, we have to move to something else. I suggest the following security technologies: * two-layer plexiglass containers with dead space in between the layers. * sensitive disturbance sensor within the dead space * glass break sensor with rapid response time inside the display case (to detect the smashing of the internal case) * weight sensors with a rapid response time inside the display case (to detect the addition of a 'very heavy' object to the display case, like a midget or child teleporting inside the case). * a remote triggering device for individual cases, tied to actuators available to the store's security staff * taggant dispersal device (<1second between initiation and full dispersion) inside the central case containing the valuables, tied to the weight, glass break, and remote trigger. * alarm to alert the security staff tied to the disturbance sensor between the internal and external cases. * security staff sufficient to cover the store (based on your total square footage, this number may be as low as one if you have a small number of display cases and cannot fit more than three customers into your store while you and the security officer are present), armed with electrical control devices (and firearms if the jurisdiction permits). You have several goals here * defeat the ability of the thief to fence your goods * lengthen the time between the first hostile act by the thief and the completion of the removal of the protected article * prevent surreptitious removal of goods during off hours * prevent non-teleporting theft * avoid injuring patrons who inadvertently trigger security measures. * alert the security staff to a theft in progress to permit intervention A teleporting thief who enters the display case directly gets a face full of taggant. A store employee manipulating the jewelery does not. A miscreant or customer who smashes the external case triggers the intervention of security staff (everyone please step back while we help this customer to their feet and fix the case//eat taser u dirty thief//there are too many of these idiots, fire the taggant). A thief who smashes the external and internal cases without triggering staff intervention triggers the release of taggant before being able to activate his MACAW. As far as the taggant goes, ideally, magically enabled 'tracking goo', invisible without special equipment or magic, that the local PD can track well enough to teleport to the thief and retrieve them within the ten minute window would be perfect. As for the dispersion device, ideally it is silent, invisible and unobtrusive (so it can be triggered during an armed assault without exposing the store staff to additional risk), but the old glowsitcks-ducktaped-to-flashbang could work too if you do not have access to fancy tech. [Answer] My first thought is to take advantage of that ~10 minute cool down. Seeing as there isn't an existing method of tracking/preventing teleportation and the shopkeep doesn't/can't comprehend how the device functions; that means we should cope with the fact that these break ins are likely to happen. Let's assume the shop is going to be broken into. **Seal the shop** These break-ins aren't likely to happen during operating hours, so naturally the shop should be locked. Install a set of motion trackers inside the shop that are designed to set off defense systems only during off hours/days. Now we have the thief; they teleport in, grab for the first thing they want to steal, and the system detects the motion. Use this to trigger a system that seals the shop (as much as is physically possible for this world and is within reason for the shop owner). Now, the thief isn't too worried because they can teleport out in about ten minutes. That's when you trigger the second system, a series of gas traps (because your neighbor actually has a really good idea). This puts the thief in an unconscious state. At best they're trapped in the shop with a bunch of gas and were smart enough to bring a gas mask. This is why you also set off an alarm that alerts that appropriate authorities and lets them know exactly what to expect. [Answer] > > Teleportation will fail if the landing location is too small or otherwise unsafe. Not sure I can apply that to an open shop though. > > > Here's the tricky thing about teleports: the landing location is always inherently "too small or otherwise unsafe", because no matter where they're teleporting into--assuming we remain reasonably close to the planet's surface, of course--it's going to be full of air that can't exist in the same place at the same time as the person. Normally this isn't much of a problem, since the air will move out of our way as we walk around, and flow around us to fill in the space we just vacated. But if our movement through space isn't continuous because we're teleporting, we've got some serious physical problems to work out in order to take care of all that air. And I'm assuming that someone did work it out somehow if the technology is in common use, because if the air stays in the same place as you appear, it could get mixed in with your body, and [that can really ruin your whole day.](https://en.wikipedia.org/wiki/Air_embolism) This means that whatever's being teleported has to displace all that air. If you want a general idea of the effects of sudden air displacement, blow up a balloon and then stick it with a pin, and keep in mind that this is a very small amount of air, both by mass and by volume. Having an amount of air equivalent to an adult human be suddenly displaced would be very noticeable, and more to the point, it would have to happen *before* the person teleports in, so they don't get embolisms and die. If there's magical technology to make this happen, then there should be a way to detect the sudden air displacement. Set up a continuous spell that monitors for it, and when it happens, forces a bunch of air directly into the space being evacuated. By the description offered, this would probably cause the teleportation to fail. If not, it would really ruin the thief's day. [![enter image description here](https://i.stack.imgur.com/bpyPd.jpg)](https://i.stack.imgur.com/bpyPd.jpg) [Answer] MACAW units seem like amazingly handy personal devices. However, the fact that they're so small and so multi-functional means they're probably not nearly as capable (at any one specific task) as a single-purpose industrial-sized state-of-the-art machine. *(In much the same way that our modern-day smartphones aren't as powerful as our desktop computers, which aren't as powerful as large-scale supercomputers.)* The company producing MACAW units probably has cross-country transporter hubs in major cities. These large-scale stationary units, being much higher-powered and much more directionally focused (pre-calibrated for very specific startpoint-to-endpoint paths), are capable of sending travelers 1000+ miles safely while hardly affecting a passenger's personal-magic recharge time. Similarly, a medium-sized, stationary (and well-calibrated) "portal" unit could be installed between a storefront and the actual store itself 50+ miles away. This benefits shop-owners in multiple ways: * **Location, Location, Location** Prime real estate is expensive. Mainstreet may be the best place to get foot-traffic into your store but every square-foot of floor space costs good money. Portals could let a store-owner build a large shop on cheap land while staying connected to a good foot-traffic location. Furthermore, a single store could have multiple "locations" if the savvy owner buys additional storefront locations that all connect back to their main shop. * **Storefront / Store / Warehouse** Bespoke items like jewelry and tailor made clothing may be created/altered in "the back room" of a store, but if land is expensive it's often the case that items are shipped back and forth to a secondary location/warehouse where workspace is less expensive. Portals allow shop owners to build their stores attached to their warehouse/workspace. This would mean a shopkeeper could keep an eye on both the front-of-house and back-of-house portions of his or her business more easily. It also means a clerk can easily "check in back" to see if a sold out item might have any more stock. * **Security** Finally, the reason the OP was specifically asking about. Since portals separate the storefront from the actual store, that means the store can be built someplace that discourages unauthorized MACAW transport. If a store is 50+ miles deep into the Earth or 50+ miles out in orbit no one is going to dare to transport there free-style with their MACAW (or try transporting back for the same reason) and therefore the only way in or out is through the "front door". Therefore typical lock-down security measures become effective again. In practice, the store locations need not be quite that remote or inhospitable so long as they still "might be" and no one is willing to test whether their getaway location is actually within MACAW distance, but I guess that all depends on how well magic-GPS works and whether or not it can be tricked/spoofed. [Answer] This assumes that your teleporting doesn't magically push things aside to make room for your arrival. Get a bunch of metal cable, and create a grid of spools in the ceiling in a grid about a foot apart. Each cable will have a weight attached to it that, and is long enough to go from floor to ceiling. In the evening, you let the cables down so the entire interior of your shop has floor-to-ceiling cables. Depending on how the teleporting determines space, they either won't be able to port in, or they will port in and will be skewered with a cable in them. In the morning, you crank the cables back up into the ceiling. So you need to clarify two questions as well: 1. Does the teleportation brush aside objects where you might land, or does it shunt you nearby? At what size/mass of object? Wires, rods, solid cement? (Heck, even dust... Do you suddenly get filled with dust when you port into a dusty room? 2. How precisely do you have to know or imagine a target location? Do you have to know any details of the shop, or do you just imagine a shop by name? What if the shop is fictional? Can you just imagine "I want to go to Betty Crocker's (a fictional character) kitchen and somehow you will go somewhere? If you or someone has to have some physical knowledge of the target location, you could defeat teleportation that way: have the shop change its internal configuration on a continuous and mechanical way so there's no way that anyone can know what the shop is like *now*. Or blindfold people before escorting them beyond the foyer, and they examine jewels while inside secure viewing rooms, never seeing the location where the jewels are stored. [Answer] There are a number of possibilities, depending on which target is being protected against: open hours shoplifting, or after hours shenanigans. First, open hours shoplifting. This would consist of people attempting to grab and item and absconding via a teleport. Since teleportation cannot be blocked usually, there is really no way of preventing people from teleporting out of your store. This devolves into two main options - removing access to MACAWs via something like a "check your MACAWs at the door" policy combined with a MACAW detector of some kind - or having an magically or mechanically automated vault system of some kind where product is represented holographically, with false-models for those who wish to touch, feel, and heft; once a purchase is completed the system would be delivered to the counter via pneumatic tubes/trained mongoose/dancing gerbils/trained birds (i suggest macaws)/magical constructs/etc, from a secure location which product is stored. This location would store items in close proximity such that at no time is there space that a human would fit, and delivers via a small method that also humans could not fit or intrude upon. Larger items would have to have some method of being picked up from the vault, probably by an assistant and teleported to the shop. In-store items would need to be inside cases that a human would not fit in, and would also need to be made of a suitably strong material... I suggest clear-steel. Solid metal enchanted specially to be completely transparent. After hours protection for the vault system, since it is too small for a human to teleport inside, would consist of access prevention, and proximity detection methods, similar to preventing anyone from entering a bank vault. In-store protection should be fairly easy, one simply needs to make the space un-safe. Retractable hanging wires/tinsel or something similar would fill the space where people walk through. Teleporting into a solid object, or having a solid object inside of you at teleport-end equals un-safe in pretty much everyone's books. As such, the teleport should fail every time. Therefore, you are left merely with more normal access prevention, just like everyone else. [Answer] The essential problem is with thieves teleporting out of the store, not with thieves teleporting in. In is easy to solve. # Puppy Dogs [![enter image description here](https://i.stack.imgur.com/s01ym.jpg)](https://i.stack.imgur.com/s01ym.jpg) Specifically, any teleporting magic will have to push out of the way any matter in the way of the incoming body. It is a lot harder to push out solid matter than air, so you're better off teleporting into non objects. That said, any displacement will cause sound and a distinctive one at that: a pop with accompanying minor air pressure shift. Easy to train a dog to get on that right quick: a tried and true method for property protection. Thieves are less likely to mess with you if they know they could get their leg chewed on. Plus real customers have a hard time ignoring the cute. It adds character to your shop! (Note that it's likely people will quickly form etiquette to not suddenly show up *inside* places, as in the [Vladimir Taltos](https://en.wikipedia.org/wiki/Vlad_Taltos?wprov=sfsi1) novels.) # CROWs The actual problem is thieves *leaving*. You've already mentioned a communication and reference watch, so we know magic exists that can communicate. All you need as a shop owner at this point is some magic that tags customers as they come in. A "cookie" if you will: Communication Originated by Offending Kleptos Intradimensional Exit. Any one passing into the store has a temporary charm laid on them that notifies the police CROW where they are should they leave the barrier area not through the door. At this juncture it's just a police case like it would be in a normal shoplifting scenario. And the thing is: it needn't be a perfect measure. It just needs to be better than the warehouse owner's measures, so thieves know to go for the low hanging fruit. (That guy really should have utilized the [choo choo train](https://worldbuilding.stackexchange.com/a/47180/6928) idea.) [Answer] You think of it as a problem. Rather, it's an opportunity. * To solve the security problem: + Magically create a [pocket dimension](http://www.d20srd.org/srd/psionic/powers/genesis.htm). Assemble your shop there. + Buy a shop (I recommend downtown Technistadt.) + Create a portal that links the physical door to the entrance of your pocket dimension shop. This way, teleporters will land on an empty shop. Here comes the opportunity! * Benefiting from malicious teleporters: + Grow a [Gelatinous Cube](https://en.wikipedia.org/wiki/Gelatinous_cube) on your shop, filling the whole room. + Befriend a [Greater Doppelganger](http://www.roleplaynexus.com/greaterdoppleganger.html). (Don't ask me how.) + When a teleporter arrive, he/she will be paralyzed by the Cube. + Let Big Doppy absorb its memories and appearance. + Retrieve all valuable possessions from the late teleporter. + Profit! [Answer] During the day you souldn't have much of a problem, just forbid MACAWs like somebody else suggested. During the night you could just store all your valuables in a safe. They can't teleport directly inside because it's too small and if they just teleport near the safe they'll have to crack it first, at which point it becaomes almost identical to any traditional robbery. Another method would be to hide valuables during the night, if the thief doesn't know where they are he can't teleport to them. This effect could be amplified by using traps. Even if the thief takes a guess thinking that, at worst, he'll teleport into an empty room and have to wait 10 mintues, you can fill the rooms with traps so that the thief will teleport into a pool of water containing venomous fish, if you don't want to kill them (the water would short-circuit the MACAW and the fish would incapacitate the thief) or over a spike pit if you want to kill/severely injure them. Yet another method would be to attack ropes with bells on the ceiling. During the day these are raised, during the night they are lowered so that any thief will set them of after teleporting in, giving you (and/or your employees) 10 minutes to apprehend him. You could also use the MAKAW against the thieves; attach one to every case (they're not lying around in the open where any pickpocket could grab them, right?) so that when it is opened or smashed the MAKAW will teleport it to a location known only to you. Or just inside a safe. [Answer] This is similar to a real-world problem that has largely been solved: shops in airports and train stations. We don't have the ability to magically teleport, but slipping away into a large crowd is disappearing all the same. Airports solve this a number of ways. Anything that's out in the open and easily grabbed is a low-value item, like a magazine or a bag of candy (not worth the expense of elaborate security). Higher-value items are sold either by [vending machine](http://www.zoomsystems.com/about-us/news-events/10-things-you-can-buy-airport-vending-machine) or in a [manned kiosk](http://www.gannett-cdn.com/-mm-/ac1394dbdcca6a36cbf486633b129cd813095ac3/r=x404&c=534x401/local/-/media/USATODAY/USATODAY/2013/02/12/xxx-business-travel-shopping01-4_3.jpg). In either case, merchandise is locked inside a cabinet until paid for. Customers can still see the goods and ask employees questions, but your merchandise isn't at risk. Jewelry is a bit more difficult since it normally needs to be tried on, but a holographic display and cheap costume jewelry replicas can eliminate a lot of that problem. When the merchandise is locked inside a display cabinet until after the sale, you largely take the teleporter out of the equation. You'd need the same basic security as in the real world - sturdy, tamper-resistant cabinets; security cameras; alarms; guards; etc - which I'm assuming would be much cheaper than elaborate traps or magic-powered security devices. The only advantage a thief would gain from a teleport is the ability to grab something from a customer *after* they've purchased it and blink away, but that's not a problem you're going to be able to solve. This sort of teleport technology would be a dream come true for a purse snatcher or pickpocket, and I'd expect most thefts would occur out in public since that presents a wealth of much softer targets. [Answer] 1. Seal your shop so it has no doors leading into the interior. 2. Create a receiving area, which is one room attached to the shop and visible through windows, into which you invite your customers to teleport, with clear and large signs. 3. Limit the time your customers spend in the shop to 10 minutes. They may leave through a one-way exit door and teleport back into the receiving area in order to continue shopping. 4. Only allow the number of people into the shop at once that can be observed by you and your staff. This could be just one, or 10--but whatever will be the number that you will not be distracted and fail to notice a new person arriving. 5. To enforce the 10-minute limit by keeping the number of customers small enough to manage, post signs that say "Any teleportations arriving inside the shop outside of the receiving area will be shot on sight." Shoot people on sight who teleport into the shop outside of the receiving area. At night time, all your display cases lower into the floor with machinery (themselves being too small in internal compartments for anyone to teleport into) and are concealed with many-inch-thick steel plates. For all you care, the walls could even retract so everything is open to the air and there is no temptation to break in--just walk into what amounts to a sideless patio. There is nothing to pick--the machinery is operated using magic (that amounts to a password that is impossible to guess). [Answer] After the introduction of the MACAW our firm is proud to present the PUT, the Pinpoint Undulation Transmitter. These piece of strips will move the desired teleportation point a small distance to a strip, allowing you to pinpoint your location within a thumb's width. The modulation phase of the strip does not influence the height of the location, this will be completely unchanged. Please remember that the translation effect begins in the range of 3 steps and forces a pinpoint landing within the range of 1-2 steps. The strips can be easily detached and incinerated on the fly. We also offer strips which destroy themselves without a trace after usage. WARNING: Please do not use a strip *inside* or near a wall, this can cause instant death or severe mutilation of body parts. > > Magic World News, 10 Springmonth After the introduction of the new > PUTs a strange series of "accidents" haunts the usage of the MACAW. > Several people have been found dead or screaming with severe > mutilations inside other's peoples stores and houses. Other people > have found themselves inside cages, fish tanks or sewage containers. > The PUT company denies any involvement and says that there is > currently not a shred of evidence that their product is responsible > and, even if there would be a connection, their legal disclaimer is > bullet-proof. > > > The MACAW company admits that it is not impossible to have deviations > of meters, but they say it is very rare and they never found a serious > deviation when used in the open field. > > > [Answer] > > I've talked to the Macaw manufacturers. They told me they are not only unable to prevent people teleporting to a certain place, but all teleports are also untraceable. Seems like a major design flaw if you ask me. > > > So talk to their *competitors* instead. Someone else will come up with a security spell to either block the teleportation in one direction or the other, or **worse**, as a deterrent, cause anyone teleporting in to materialize inside-out. [Answer] If a macaw is small enough to fit on someone's wrist, then there is no reason why a macaw can be installed as part of the entire shop. Now a smash and grabber teleports in to rob your shop, the macaw immediately teleport-ejects any potential thief from teleporting in. Security by teleportation. However, there will need to be a selection mechanism to prevent legitimate shoppers from being ejected. There could be a welcome area where shoppers can teleportatively land and be vetted as shoppers and not thieves. Landing anywhere else in the shop will lead to automatic ejection. [Answer] Install a CITY (Crystal Induction Transparency Yard) in your store. And then encase all of your goods in a block of MAPP (Magically Altered Pseudo-Plastic). The properties of MAPP are: * Generated by a CITY, in the shape the user desires * Resists scrying * Nearly transparent while in the matching CITY * When removed from the matching CITY, becomes opaque and black * When removed from the matching CITY, emits a loud, annoying tone * Can be dissolved harmlessly while within the matching CITY, but only with a specific, magic key (as in a spell and password, not a physical key) * If damaged (even in the CITY), the damaged layers transform into a highly corrosive substance that does not damage the remaining MAPP The CITY is generated by a special, specific crystal, and the energy of the person who charges it. One charge (about the same energy as one teleport) will last 64.8 hours, but the crystal can hold up to five charges (to allow for vacations). Because the CITY relies on both the shape and structure of the crystal, and the specific energy of the user, it is nearly impossible to duplicate. Even if the goods are stolen, they will be difficult to sell if the buyer can't see what they are (or hear what the thief is saying). And if the thief tries to dig them out, he risks injuring himself, and destroying the jewelry; either by hitting it because he can't see it, or by having it dissolved by the MAPP corrosive. Any legitimate customer can still see the goods. And they are easier to display and store because each it in its own transparent cube/rectangular prism. [Answer] Most of these answers seem too complex, no need for nerve gas and Faraday cages. # Nighttime: Bar up the display cases. Most people bar up their shops, but now the thieves can get past that, so simply move the bars further in. With the right set of bars and locks you can stop all but the most determined thieves. For that case, that is what insurance is for. # Daytime: A gun. [Answer] People teleporting in or out don't really matter. What matters is **your stuff** getting teleported away. Well, there's a market for disposable security labels like this one: [![RFID label](https://i.stack.imgur.com/orcCu.jpg)](https://i.stack.imgur.com/orcCu.jpg) Typical set should consist of label-sealing device (unless they are self-sealing), label-removing device (ideally only working if it's provided with the same code as label-sealing device, only at working hours and inside the store) and a ton of labels - those are expendables and producer would be making his profits off them mostly. If you sell a thing, you remove a label from it (or deactivate the label). Those labels should be as small as possible so they don't deface your goods. Having met that, they could be as cool as you would allow them to be - maybe having some alarm system onboard or even means of subduing the carrier - but that's not necessairy. Local cops would *love* the device that automatically notifies about thief with evidence on him any cop that walks by. Systems from the same vendor could collaborate so alarm is triggered for any label out-of-its-place, even if it's from another store (so your thief would be busted while walking past some supermarket, for example), but that really depends on pricing and may be unfeasible. If MACAW technology can be applied over arbitrary shapes you have a **much** bigger problems though. [Answer] **Every one here seems to be considering ways to thwart the M.A.C.A.W.** If it is amplifying a persons innate magical ability, then all one has to do to prevent it is remove that ability or lessen it to the point they can only teleport a few feet. Larson's Botanical Lexicon states that > > "*witch-bane:* is harmless to most creatures, excepting those that need magical energies to maintain shape or form. In the case of willfully wielded magic it will counteract that in the conjurer which allows him cast the spell." > > > In that effect, I have heard tell that it emits quite a pleasurable odor that may also have an added affect of soothing difficult negotiations. [Answer] The simplest method to prevent a would be thief from teleporting into a store would be to surround the entire structure with a device that behaved like a Faraday Cage. A Faraday Cage can block out electromagnetic waves including high voltage electricity, as well as radio waves, television waves, WiFi signals, etc. It should also prevent the electromagnetic waves from passing inside of it from a teleporter as well. The owner would simply need to have a cage built around the store so the thieves cannot teleport inside. [Answer] Due to the cooldown, teleporting into the shop is really no concern since people will use the device to teleport out, not in. That's why the accepted answer will only deter real customers and provide absolutely no defense against real thiefs. **In theory**, you'd use the same methods used today: * Insurance * Overnight safes * Cameras, or other means of identification * Law enforcement **In practice**, law enforcement is completely useless because they can't arrest anybody - any bad guy who's stopped by law enforcement will just teleport to a random untraceable location before their identity can even be established. Because law enforcement wont be able to arrest anyone - be it thief, murderer, rapist, or slaver - society will crumble, and you will face looters rather than thieves. What you really should do is sell your shop while you still can, buy/build a hidden bunker, store lots of food, and **wait for the inevitable collapse of civilization**. [Answer] The ideal solution would be something akin to a lodestone for teleports. Anyone trying to teleport in to the shop lands in a receiving room, which could be nice and open and a regular way to travel to the shop. (possibly with a nice door chime) Anyone trying to teleport out of the shop would likewise land in the receiving room, with ringing bells etc. the door could be locked from the inside, and customers need to be "buzzed" out. At night the room could be far less nice, and less open. :) [Answer] Assuming 5 miles is the maximum you can teleport accurately, simply(!) build your shop in a location that is inaccessible within 5 miles. This could be a bunker under the ground, in a mountain, or even floating high up in the sky. If you built it 5 miles beneath the ground, and put a secure building above it (something impossible to teleport into, for example by making it heavily trapped or with a security system that is manually disabled during the day) then no-one would be able to get into the shop unless they teleport from above during working hours. You could extend this, to having to teleport twice to enter the shop, by building your ship 10 miles under ground and having a 'stop' half way where while you recharge. This will stop you from being able to flee if something is stolen. If there are any materials or signal jammers that can shorten the 5 miles then this will help in constructing it closer to the surface. However... A much simpler method however would simply be to have a pressure plate that measures the weight of everyone in the room. If someone spontaneously appears the building goes on lock down (or if it's night, the intruder is shot or sprayed with jam). ]
[Question] [ Everyone suddenly disappears from earth except 35 people randomly scattered wherever they were before everyone disappeared. How long would it take on average for 2 or more people to meet? What other factors would indicate to a person that they're not the only person who didn't disappear? [Answer] Assuming that it's purely random, let's consider where these people would probably be. Taking the [percentage](https://www.worldatlas.com/articles/countries-by-percentage-of-world-population.html) of the population each country represents, we get: * China: 18.2% = 6.37 people * India: 17.5% = 6.125 people * America: 4.29% = 1.5 people * Indonesia: 3.43% = 1.2 people * Pakistan: 2.78% = 0.93 people ...etc. The percentage keeps going down. This means that roughly 6 people will be in China and India, each, and then the next 7 countries or so will probably have 1 survivor each (maybe 2 for America). The other 15-16 survivors would probably be found somewhere in the next 25-30 countries (as the probability of having any survivors approaches 50% or less). So really, our most likely candidates for people meeting each other are China, India, and Europe ([9.83%](http://www.worldometers.info/world-population/europe-population/) of the population as a whole for probably 3, maybe 4 survivors). For India, [72.2%](https://en.wikipedia.org/wiki/List_of_million-plus_urban_agglomerations_in_India) of the population lives in 641,000 rural villages, and this population is pretty [evenly distributed](http://www.indiaonlinepages.com/population/gifs/population-map-of-india.jpg), meaning 4-5 of our 6 survivors are probably located on a unique patch of 650-820 thousand square kilometers ([3.2 million](https://www.google.co.jp/search?q=india%20area&rlz=1CAASUG_enJP811&oq=india%20area&aqs=chrome..69i57j0l5.1391j0j7&sourceid=chrome&ie=UTF-8&safe=active&ssui=on) square kilometers divided by 4-5 people). This means they could walk for 800 kilometers in any direction, and never see each other. The only real chance that they'd ever find each other would be if they all decided to go to the same major city. But which one to choose? There are 53 cities in India with over 1 million people, and at least 8 with more than 5 million. Would someone in the populous region of Bihar go the 1300 km to Mumbai, the biggest city, or the 800 km to the capital of New Delhi? If you go to the wrong city, will you travel another several hundred km to a different city and hope your luck gets better? Most people are more likely to go to ground, either before any travel, or after failing to find someone after travelling once. And even if two people, by chance, happen to go to the same city, it would be rather unlikely that they'd run into each other. Let's take Mumbai, for example. It has an area of [603 square km](https://en.wikipedia.org/wiki/Mumbai), which increases to almost 4400 square km including the metropolitan area. This means that two people would have to run into each other in an area that is roughly 25-70 km across and deep. Chinese survivors have the advantage in that their population is [concentrated in cities](https://en.wikipedia.org/wiki/Demographics_of_China#Population_density_and_distribution), but with a [maximum metropolitan area](https://en.wikipedia.org/wiki/List_of_cities_in_China_by_population_and_built-up_area) holding only about 3% of the population, the survivors are still likely to be scattered all across China, or at least [the eastern half](https://en.wikipedia.org/wiki/Heihe%E2%80%93Tengchong_Line), which still has an area of about 4 million square kilometers (greater than that of the entirety of India). The issues with choosing a city are also present for survivors looking to migrate, as Shanghai, Nanjing, Beijing, Hong Kong, Guongzhou, etc. are all major cities. For Europe, this only gets worse. The area expands to 10 million square kilometers, and unlike India or China, which have their own capitals that could act as a rallying point, each country in Europe (which would probably have at most one survivor) would probably attract survivors to their own capitals. A single German survivor, for example, would likely head to Berlin rather than Paris. So in summary: most survivors would probably be scattered over an incredibly vast area (hundreds of thousands to millions of square kilometers for a single person); if they decided to go to a big city to intentionally look for other survivors, there's a good chance they'd go to different cities than each other; and even if two survivors both decided to go to the same city, finding another person in even the same city is rather unlikely. [Answer] ## It's HF radio, or nothing **The odds of anyone meeting again are almost exactly equal to the odds of at least two being either radio hams, or able to learn the skills from books.** The population density of 35 people worldwide is so extremely low that the odds of finding someone without the benefit of global communications is practically zero. Strategies like finding a printing press and posting thousands of fliers in different cities are a bold try, but they are hopeless: they fail to grasp the massive scale of the task. You could distribute 100,000 fliers in each of a hundred cities: and your odds of finding someone are still very, very long. So it's global comms, or nothing. Internet comms could work, but you have a matter of at most a few days to sort yourself out before the system fails. Act quick: find someone, somewhere, amidst all the autogenerated cacophony and BS, in the next three days. Time's up. HF radio, on the other hand, is highly resilient, extraordinarily efficient global communication system. It can remain operational until you run out of spare parts -- the power requirements for [QRP operations](https://en.wikipedia.org/wiki/QRP_operation) can be met by solar, batteries, or even pedal generators. There are standard hailing frequencies, standard protocols. Including standard protocols for global catastrophes. You might not make contact the first time you try, but if you keep trying, it approaches certainty. Yes, HF radio is a skill. But you have the rest of your life to learn it, or die alone. [Answer] This is an interesting question. Obviously, just walking about and hoping to meet someone is fruitless, the chances are just ridiculous. What you would want to do is **communicate**. Now **we** know how many people survived and what the likely distribution is, but **they do not**. From the perspective of a survivor, everyone around is suddenly dead or disappeared. Unless you are criminally stupid, your first thought will be about survival. Short-term that is not a problem, go into an empty shop and take what you want. Mid-term you are down to canned food. Long-term, you are going to have a serious problem. So you want to get to a city edge and set yourself up there - with both farmland and supply depots (aka supermarkets and other shops) within reach. That also means that - at least at first - the city center is just a quick drive away, provided that whatever catastrophe took everyone else left the roads useable. Since you don't know if there are other survivors and how many, you would pick a landmark site, something others would think about as well, and post a written notice there. This is easy, low-cost and thus something that makes sense to do "just in case", even if it is fruitless you didn't invest much. You would also post on FB, Twitter or whatever websites your frequent, just out of habit "hey guys, what is going on?" and for the same reason - it is easy. Most of the answers so far assume too much knowledge and thus targeted activity on the side of the survivors. The Internet would probably be down by the time you start any targeted activities, as pointed out in other answers. Your billboard notice is a gamble, but you don't know the odds. It is, however, the most likely thing to work, as it is intuitive and doesn't require to people to be in the same place at the same time. Especially if people go roaming, there is actually a reasonable chance that they would meet. Let me explain: Once you got the survival thing down, you are left in a world with plenty of cars and practically unlimited fuel - for a time. Current fuel goes bad in about a year, and the cooling etc. required to keep it longer will fail together with the electricity. Once you realize that a) there are very few other survivors, if any and b) survival alone is much more difficult than in a group, the logical next step is a game of "what would the others do?" And I believe it is trivially obvious that everyone would head to the nearest largest city. The capital. Leave a message there, in a central place. In Europe, you would take a car and drive to Paris, post your notice at the Eiffel Tower. Then drive to Berlin, post at the Brandenburger Tor, and so on. Invite others to leave their messages so you know someone else is alive and then POST YOUR ROUTE. Make it a circle through the 5-6 major cities in the area and drive it two or three times. You can easily cover the distances (again assuming roads are free) in 1-2 days. You can do this early when supplies are not yet an issue. If after 3 or so rounds you see no notices and nobody waiting for you at the next stop, assume the entire area is empty and go elsewhere. If you start out in the Americas, good luck. If you start out on an island, go farming and enjoy the rest of your life. [Answer] (This answer supposes that electricity and the internet survives for a day or two) Either a couple of days, or many months, if ever. ## **CALLING OUT TO ALL SURVIVORS** --- ## **Hello!** --- Everybody in the world has disappeared. Considering that you are reading this, electricity, the internet, a search engine, and Stack Exchange must still be working, and you had the state of mind to search for "why has everybody in the world disappeared". Congratulations, there is hope to reach other survivors. The fact that you can read this means that The Event must have happened very recently. Once it's down, everything will be so much harder. Please search and post on ~~Twitter~~X, Sina Weibo, Mastodon, or other microblogging services using the hashtags: ``` #anybodyoutthere #有别的人吗 #क्यावहाँबाहरकोईहै #alguienporahí #هلمناحدفيالخارج #ilyaquelquun ``` (**Please edit my question before The Event happens to correct the hashtags, in particular for Chinese, Hindi, and Arabic, and replace them with a more colloquial phrase**) And describe **where you are**. Please confirm that you have read this message. Translate your message and the hashtag with Google Translate in the most common languages. Continuously check Twitter to see if anybody follows suit. Learn how to produce electricity with solar panels, and how to operate radio, if you don't already know how to. Initially you may be able to use the internet for this, but soon you'll have to raid a library for this. See [Securigers answer](https://worldbuilding.stackexchange.com/a/122567/2044) for more on radio. If you manage to reach people this way, discuss together what to do. If you don't, it's time to start travelling. Try to drive a car, even if you don't know how to. I don't know if the roads are accessible, but there should be plenty of cars with fuel available. If you can't refuel, switch cars whenever you run out of fuel. Maybe the event happens when most/all cars are electric. Search for solar-powered recharging stations; solar panels can last a long time even unmaintained, so you're in luck. If you are in Eurasia or Africa, please all head to the Eiffel Tower, Paris, France [Baiyun Mountain](https://en.wikipedia.org/wiki/Baiyun_Mountain), Guangzhou, China. Probably half of survivors live within this circle and Guangzhou is right in the middle of it. From Western Europe you should be able to drive there in around 3 weeks. ![half the worlds' people](https://assets.fastcompany.com/multisite_files/coexist/imagecache/inline-large/inline/2013/05/1682016-inline-asia-circle-zoom.jpg) If you are in North or Central America (anywhere north of the Darien Gap), please all head to Boulder, Colorado, United States. If you are in South America, please all head to Christ the Redeemer in Rio de Janeiro, Brazil. If you are anywhere else, I hope you'll be able to navigate a boat to any of those continents. During your travels, please pass by as many major urban landmarks as you can, and **leave many traces**. This is not the time for practising wilderness ethics! I hope there are fellow survivors. If there are, they may also find this message. I hope you will reach each other. If you find each other before the internet goes, you might know about each other's survival in days. Otherwise, it may be many months, or you might never realise. Good luck. I don't envy you. [Answer] I figured, since a lot of people are bringing up the [Birthday Problem](https://en.wikipedia.org/wiki/Birthday_problem), I'd add a separate answer just for discussing it. Simply put for those not familiar with it, the idea is that based on probability the actual number of individuals needed within a sample before overlapping becomes nearly certain is far less than the actual number of possibilities. The original problem discusses how many people you need in a group before you are almost certain to have two people with the same birthday. Obviously 366 people means that it's 100% certain (discounting leap years), but 70 people gives a 99.9% certainty of at least two people having the same birthday, and even just 23 people gives roughly a 50% chance. So let's apply this to the current problem. The first question, though, is how we should divide the world to check it. The most logical way to do this is via population samples, since geographical area obviously won't have equal weight due to variable population density. Let's use 40 million, as that's around the size of most of the [largest metropolitan areas](https://en.wikipedia.org/wiki/List_of_metropolitan_areas_by_population) of the world (Tokyo, NYC, etc.). Given [7.6 billion](http://www.worldometers.info/world-population/) people, this would give us 190. Using a [calculator](https://www.dcode.fr/birthday-problem), this would give us a surprisingly high 96% probability of at least two of our 35 people sharing the same population segment. Now, this may seem impressive, but one must consider that 40 million people is the population of many [Indian states](http://www.indiaonlinepages.com/population/gifs/population-map-of-india.jpg), or any 2-30 [American states](https://en.wikipedia.org/wiki/List_of_U.S._states_and_territories_by_population) (with a few exceptions such as New York or California). "There might be two people who are both in [California](https://en.wikipedia.org/wiki/California)" isn't too helpful, "There might be two people somewhere in the American Midwest (sans Illinois/Michigan)" is less helpful, and "There might be two people in all of [Canada](https://en.wikipedia.org/wiki/Canada)" is even less so. So let's reduce our search to within a unit of 10 million people. That's about the same as [Tokyo proper](https://en.wikipedia.org/wiki/List_of_cities_proper_by_population) or all of the country of [Greece](https://en.wikipedia.org/wiki/List_of_countries_by_population_(United_Nations)). Now it's a little more specific. Reducing our population by a factor of 4 increases our number of sections by the same. So now we have 760 possibilities. This brings our odds to about 55%. Still larger than might be expected, but it's now a coin flip as to whether anyone is in the same city proper, or section of a populous state. Now, that's not to say that it's a coin flip whether someone is in the same population sample as any other given person. If you were a survivor, it would not be a coin flip that a second person in 10 million also survived in your area, but rather a coin flip that there is a second person *anywhere*. There's a 16% chance that a second person is in the same 40 million original population section as you (1-(189/190)^34), and 4% chance that there's another person in your own sample of 10 million. Now, though, let's consider this by area. For example, if by "randomly scattered" the OP means "picked up and dropped in random locations". (The Birthday Problem requires equal probability, so this approach isn't really applicable to realistic distributions.) Given roads and long views in rural areas, let's consider the world to be one fifth as large as it is. This helps reduce the effect of deserts, mountains, and other boundaries, as well as the effects of people travelling on roads. (Let's call this our "scaling factor") So we have a land area of around [150 million](https://www.infoplease.com/world/general-world-statistics/profile-world-2016) square kilometers, reduced to 30 million square kilometers from our scaling factor. Let's say that you can find someone within 30 kilometers, about the size of a large city, when they fire a gun, honk a car horn, etc. This gives us an area of 900 square kilometers to locate someone within. Let's call it 1000 to make things nice and even. 30 million over 1000 gives us 30,000 land units. The odds of two people both "spawning" in any single land unit of 1000 square kilometers would be about 2%. This is actually surprisingly high, but still means that it is unlikely that anyone would start within 30 kilometers of each other. Though the odds of two people "spawning" within 100 kilometers of each other (about 10 times more area) is actually only about 18%, which is amusingly high. Though again, this is *anyone, period*, not the odds of a you having a partner in your 100x100 km area (which would be around 1%). [Answer] With only 35 people left, nobody is left to monitor the electricity powerplants and perform the recurrent operations (like refueling or manual checks) that are part of any plant, so most plants will automatically shutdown within hours, and with them all modern communication means. So here is an answer that assumes there is no phone/Internet/etc. A common survival technique is to find a river and [go downstream](https://outdoors.stackexchange.com/a/252/5515), until you find either someone or the ocean: > > If you can't make out any signs of civilization, look out for rivers or streams. Head for those streams and follow them downwards. It is highly likely that you will find civilization downstream. > > > Among 35 people, many (A) will come up with that idea after a few hours or after a few years, and at least try once after finding nobody in their nearby cities and in their country's capital city. I am not saying everybody would immediately do it, but many would certainly try it. Even with GPS not working, following rivers is relatively easy. Most inhabited regions have roads along rivers. There are many rivers that throw their waters directly into the ocean, but the great thing is that some rivers have huge drainage basins: [![enter image description here](https://i.stack.imgur.com/FTRgi.jpg)](https://i.stack.imgur.com/FTRgi.jpg) There is a reasonable probability (B) that two people are in the same drainage basin, for instance in the Ganges (India/Bangladesh). If these two people go downstream and leave messages once in a while, they have a non-negligible chance (C) of walking through a place where the other has or will walk. Most the people will intentionally or not leave hints after their passage, for instance if I went along this river I would try to write a message on that tree or on the white wall of the riverside building in the background: [![enter image description here](https://i.stack.imgur.com/LExHZ.png)](https://i.stack.imgur.com/LExHZ.png) Via these messages the two people have a small probability (D) of eventually finding each other. My estimate: * A: 50% * B: 30%, math pending * C: 30%, rather low because: 1) Rivers have two sides 2) Some rivers have complex estuaries 3) Detours for food/etc * D: 20% Result: 1% chance. Which is not that bad. Note: * How will people be able to walk long distances? No planes nor trains, of course, but we have to remember that these people have the remainder of their lonely lives in front them, so they have time plenty of time to find a house left open (people have disappeared, including those who were at home, and a large fraction of them probably did not lock all doors), and borrow the car keys hung on the keys rack behind the door, check how much gas is in the car, and find another car this way when fuel is low. Nearly each petrol station has fully-fueled vehicles with its keys on the floor near the cash register. The smart ones will find a good bicycle and put it in the car, or even figure out how to get [jerrycans](https://en.wikipedia.org/wiki/Jerrycan) and how to use them. Unfortunately, gasoline goes bad after half a year, so after that people who have not figured out anything smarter will have to rely on bicycles again. [Answer] Given the scale of the Earth, and a purely random distribution, the odds are negligible that they would ever meet. Each person would have 4.2 million square kilometers of land to themselves, on average. [Answer] To realize they are not alone will depend on the people, the technology available to them and the knowledge of the internet or communications. Assuming they are distributed across the world and no one is physically close to each other, they will still be able to contact each other online. Websites or online forums like Reddit, Stack overflow might be easier, since you can directly post and you will be the newest thing, while other social media websites like Instagram or Facebook will be a bit more difficult, as they show things you are interested in or related to and hence you may never meet online. There are also other options like forcing your search to be number 1 on google trends, which wouldn't be too hard or looking to see if there are any new articles or information out after the date (you will have to be careful of bots, but there are plenty and you will probably think they are real people anyway). (Several hours to several days). Depending on their knowledge, they may also try and find and use/modify communication devices to broadcast to everyone they can. Things like Radio, TV or Satellite can allow them to send out a signal and hopefully someone else is listening in on them. Maybe they are a journalist for a newspaper and publish an online article. There would be lots of options. (Hours, to weeks). Finally, you might get a couple of wanderers who will travel across the country and continents looking for anyone else. You would leave signs behind to signal that you exist and where you are heading while you travel. (Months, to years). So down to your question, how long will it take for 2 people to meet? Well it depends on how far away from each other they are. They need to be able to travel to each other so your time frame starts at instantly (the person happens to be in the same room), to several months (Via ship over the open sea, but only if they know how), to several years/never (aka time to learn how to fly/sail and try it out). Of course this all starts from after they discover each other and confirm they are actual people and not hot singles in your area. So if you wanted an average time, I would say around 5-7 days. If you think about it, over 30% of the worlds population is in china and india and over 50% in asia. There is a very high chance that 2 or more people will be in the same country and once they link up they should be able to get to each other fairly quickly by driving (You can cover several 100Km's a day by driving and there will be no one to enforce speed limits or stop you from stealing a fancy car and fuel). [Answer] The Earth has a surface area of 196.9 million mi² (510.1 million km²) (land mass only). On average, that means each person will have 4.8 million mi² (14.6 million km²), which is equivalent to a square 2203 mi (3818 km) on each side. That's roughly the distance from New York City to Los Angeles. It is *enormously* unlikely that anyone will ever meet another soul before they die if they were uniformly distributed. The best hope for this argument is that people are not uniformly distributed. [55% of people live in urban areas](https://phys.org/news/2018-05-percent-world-population-urban-areas.html). These urban areas [cover](http://www.newgeography.com/content/001689-how-much-world-covered-cities) 3.5 million square kilometers. This means that 19 of your 35 people will likely be from these urban areas, with only 184,000 square km to each -- a square 429km in length. That's a bit more than the distance from New York City to Washington DC. Now we're getting somewhere. Still a terribly long distance. However, there's one more trick up our sleeve. This is a [birthday problem](https://en.wikipedia.org/wiki/Birthday_problem), because any two of the individuals being close together will do. I'd need more accurate demographics to see how much this affects things, but it makes it more likely that at least one of the pairs is within roughly 20km! Of course, there is a huge catch here. Those who are in urban environments are far less likely to have the survival skills required to live for a very long time and execute such a search. While those who lived in rural environments will likely live out their lives without too much additional difficulty, urban survival will call for a new set of skills. It is unclear how much this will affect things. [Answer] A thing that seems not to have been addressed yet is the age and survival chance of the 35 non-vanishing persons. Depending on the mode by which the rest of humanity vanishes, many of the chosen ones might just die in minutes or days Reasons would include among other things: * having been in the car/ship/train/airplane where the driver/captain/pilot vanishes, resulting in an accident * being to old or too young to care for oneself like a baby * being incarcerated at the moment or being otherwise stuck * going insane and commiting suicide shortly after the event The already small chance of ever finding someone else diminishes further, if you simply die. Even if the other person is "close" (i.e. a few kilometers away). However, when you know where the other person is, the meeting probably can be done in a few weeks. So the initial communication infrastructure would be most important. If the Internet stays active long enough, people could get in touch quite fast - just post and visit pages on popular sites, where actively viewed content is featured. Again, this depends on the age/culture of the persons in question - a senior in a rural area might not even think of this. Similarly, the already mentioned option of radio communications requires some expertise which could be missing among the surviving portion of the 35.. If they are going to meet, retain more people than 1 per 200 million. (of which probably half would be dead in a week) [Answer] Of your 35 survivors, it is likely that 7-8 of them are Muslims. I imagine that at least a few of those might decide that now is a particularly good time to undertake [Hajj](https://en.wikipedia.org/wiki/Hajj), a pilgrimage to Mecca. Particularly as such a pilgrimages are organised to arrive on the same day, then it is quite likely that they would meet each other there. [Answer] Foreword: This may duck the spirit of the question for the literalist interpretation. **Thinking Outside The Box** [![Alternately, thinking outside the sphere](https://i.stack.imgur.com/LiAKB.jpg)](https://i.stack.imgur.com/LiAKB.jpg) If I was a '35er, the very first thing I would do is hop on my smartphone and start hailing the ISS in every way I can manage. At [their twitter](https://twitter.com/Space_Station?ref_src=twsrc%5Egoogle%7Ctwcamp%5Eserp%7Ctwgr%5Eauthor), at [their Insta](https://www.instagram.com/iss/), if I can find a HAM radio I'll darn well hit em [there](http://www.ariss.org/contact-the-iss.html). I'll try the astronauts personal twitter, email, linkedIn, whatever I can possibly find. I believe this will be a doable effort. Even if there are bots creating bogons, I believe the only person tweeting, emailing, DMing, Hamming, about how they've lost contact with Houston will eventually make contact. The ISS has (very slow) internet access and I believe it is a much better option than HAM for making and maintaining the contact we will need for this next step. Even if you can't maintain contact over the short longer term, you have made contact with a very important asset. The astronauts on the ISS are the only humans guaranteed to be alive at this juncture. Any attempt to quickly (day of, day after, while internet survives) pick out and contact another survivor seems doomed to fail in my opinion. **The Plan** The Astronauts are an incredible asset in your plan to save the human race (lets face it, without your action, there ain't no chance of more babies). They will allow you to greatly increase your communication output in the crucial period before the global communication network shatters. You email every person in your email contact list. You message everyone you have on facebook or any other social network. MAJOR KEY ALERT: you try to find the address of your closest HAM radio club or organization. Dig for details of either the first member you can find (time-sensitive internet access) or the closest member to your location (transit time contingent). Download a copy of the two most popular Ham radio operation manuals you can find on E-Book (you can always get one at a library later, believe me you'll have the time for it). Meanwhile, have the ISS do their part. They will have a more traditional array of communications tools alongside their slow internet. They are all exceptional people and bring a set of skills, knowledge, experience, and raw brainpower that you alone could never match. Follow their instructions if they seem reasonable and try to avoid wasting time communicating about their unavoidable long-term death. **Short Term Contingencies** Now, this first stage of the plan is contingent on a few things, luck first among them. Depending on the circumstances of the disappearance and your own personal situation, a car could crash, take down a line or generator or other sundry key part of the communication network linking you to the ISS. This is too terrible to contemplate so I'll not bother. Answers to [this question](https://worldbuilding.stackexchange.com/questions/106688/how-long-would-the-internet-be-usable-if-nearly-all-humans-disappeared) seem to think otherwise have a set of 2-5 (ok maybe not five) days before the internet is pining for the fjords. **Back to the Plan** The time between when you make contact with your team and when you lose them over the internet is precious beyond simple explanation. I personally cannot imagine what brilliant things you could come up with, under extreme "motivation", with decades of their experience as soldiers, academics, or whatever. 232 extraordinary global citizens have spent time ex-terra at the ISS Hilton, so you *could* have more or less any combined skill set up there. What I suggest seems reasonable to me under these bounds. You take control of the ISS personal astronaut social media accounts, the ISS social media accounts, the NASA social media accounts, and/or any other email-linkedin-weichat-VKontakte accounts you can. If anyone has the talent to hack or learn to hack quickly, take control of any and all social media, news, or simply popular webpages you can. Take into hand any further ISS-based communication equipment, and broadcast a looping screed of "Are you out there? We are still alive! us at !". If you can take control of printers, print your the address of your nearest town hall (to be left with a briefing cache) along with the above message. You have cast the widest net possible in the shortest time possible. Await responses while brainstorming your next step over email with the spacers. Download a translation program and a set of dictionaries to a flash drive and use google translate while you still can. If you get any responses, generically tell them to acquire a ham radio and a generator before proceeding. See if you can get them hooked up with the ISS if you can, to facilitate communication. If you can figure out a potential halfway-point for future meeting, hash that out. My guess is that you don't see any response (you can cast a big net but earth is large as hell with balkanized communication for the most part), but you've given it your best. Either way, form a plan for continued (personal and species-level) survival. At some point you'll have to switch to a Ham Radio for (much reduced) ISS communication (which will end one day) and a library for research and planning purposes. **Going Forward** 1. Survive! If your person doesn't survive, nothing else matters (to you). 2. Help others survive! Even if you can't reach them, assist them in any way you can. Keep in HM radio contact as often as possible, and pool your (foodgathering, medical, transportation) information, and socialize. It would be very easy to get discouraged or suffer from mental health issues in this scenario. 3. Form a community of survivors. Travel to a centralized site with access to food, resources, and information. Choose a language (please god no English or Chinese), form a society, have kids. Choose a leader and stick to it because god knows you can't afford a civil war. 4. Make your community safe. You'll have a Mayflower's worth of people, with no guarantee of carpenters nor doctors. Based on [this chart](https://blog.adioma.com/what-7-billion-world-population-does-infographic/) and your ability to contact, preserve, and gather your fellow humans, you will have a very limited workforce with limited skills. Choose a safe (good weather and limited natural disasters) location and exploit existing structures and resources, like farms, orchards, quarries, etc. 5. Preserve Knowledge and Progress. Form a religion to preserve knowledge, human rights, and provide for the people. To what extent you can, mold your society around reclaiming the mantle of humanity, reclaiming progress, and preserving the environment. This is your chance to change the course of human history. Even if in the future, regionalism and person ambition breaks your community into different groups, you can hope your church will tie them together culturally and diplomatically. I'm aiming for a mix between the state-within-all-states Early-Middle-Ages Catholic Church and Star Trek's Federation. **Acknowledgements** What I detailed above is by no means the most likely scenario. It is simply one scenario, and one far more positive than most of the answers so far in my opinion. [Answer] Was going to do this as a comment, but decided to write it up: Total landmass on earth: 148.94 million km^2 (148940000km^2) - approximates to a square ~12300km on a side (Might be entering spherical cow territory here, but bear with me) Randomly distribute 35 people within that square and calculate the minimum distance between *any* two of them Repeat\*100 Sum up all of our minimum distances and divide by 100 to get the average - ~70km or less! This is due to the what @Cort Ammon mentioned - the birthday problem - as the number of people goes up, the chances of any two of the being close rises exponentially This of course assumes that people are evenly distributed, which they aren't, It also ignores the shape of continents, oceans, and travel difficulties [My incredibly rough calculations in a python script:](https://repl.it/@melkins91/Rough-Pop-Distribution-Calcs) NB: please forgive my horrible code, it's just meant to give an idea of my thought process and maybe act as a jumping off point **Factors which will affect the time it takes for two of them to meet:** * Radio contact - two of them getting a ham radio set * One of them being in a position to spread news effectively - i.e. online news, emergency broadcast * How long infrastructure stays operational * If one has access to information that can track survivors; emergency services, mobile phone network, reddit? * How easy it would be for a single person to stand out amongst the noise generated by automatic processes such as bots, queues of updates for websites etc [Answer] The headline and the detailed question are not equivalent. *If everyone in the world disappeared except 35 random people, how long would it take for one of them to realize they're not alone?* is not the same as *Everyone suddenly disappears from earth except 35 people randomly scattered wherever they were before everyone disappeared. How long would it take on average for 2 or more people to meet?* It depends on what you mean by the word "realize." That's not the same as "prove." How long did it take the human species to "realize" that there were not alone (or better, in a vast if not infinite universe or multiverse, extraordinarily unlikely to be alone) as a self-conscious species, even though none had ever been encountered? So what is required is for one of the thirty five to "realize" that if s/he survived then there are two possibilities. Either out of 7.4 billion people s/he is the only one, or there are others. If one person survived then that is proof that it was possible to survive. Given that the thirty five were taken at random, it is reasonable to assume that there were no special circumstances relating to the survival of that individual, indicating that there were 7.4 billion chances for at least one other to survive. As with the case of intelligent life on planets other than the earth, the huge number of other possibilities for life, i.e. survival, would lead me (if I was lucky or unlucky enough to be one of the survivors) to almost immediately "realize" that there were overwhelmingly likely to be others, even though it might be very unlikely that I would ever meet one. What is the chance that of thirty five random individuals one would think the same way as me - pretty good, I'd say. [Answer] Get something like <https://en.wikipedia.org/wiki/Satellite_emergency_notification_device> and hope that someone manages to hack into the data center and receive your message. Combine with other methods such as HF radio. [Answer] This is another Birthday Problem answer. It seems likely that two people could find each other (if that was their goal) if they were in the same city, as cities have centralized layouts and are small compared to countries. So one way of addressing this question is to ask: how likely is it that two people would remain in a single city? I chose simulation, finding a list of about 50,000 cities and their populations. The total population was about 2.2 billion out of an assumed population (US census bureau) of 7,494,217,000; I assumed that anyone not falling in one of those cities would have 0 chance of finding any others. In 7 out of 100 simulation there was at least one city with two or more people remaining, suggesting that the probability is between 5.5% to 8.5% with ~95% confidence. [Answer] In order to realize you are not the only one, you have to meet another. That in itself is a major challenge even if you use one of the more sensible strategies suggested in other answers. The success of the strategy also depends on someone else using a strategy compatible with the one you chose. So, what is the probability that two or more of 35 people who see no evidence that anyone else exists will think that there *might* be someone else? Then, what are the chances that those two or more but less than 35 will think that it is worthwhile to try to find each other, and then that the ones that think so will design methods that have a chance of working? On the other hand, if two of them happen to be fans or followers of a popular page/account on a social media site, **and** keep looking at it in spite of it having no activity after they notice that apparently they are alone, one of them might post “WTF happened?” and the other see it. Once they realize there is one other, they may be motivated to collaborate on a search for others. Finally, are those 35 truly random? Or is there something they have in common that exempted them from the disappearance? If so, is that something that will increase the probability of some of them knowing or suspecting there are others? [Answer] With radios yes, without technology .... no Does it have to be 35 people? Why not 356, 1 for everyday of the year. Then you can at least have a few people setting up radios in different citys they visit and maybe leaving repeating messages. And eventually, after maybe a 3-5 years maybe even a decade if 200 or more are still alive, someone would find someone. 35 Is just way to low, unless you're planning on inventing ways for them to have electricity and communication methods for at least a week but even then a month would do much better, but that would be impossible as much power grids would fail in 12 to 48 hours for major areas maybe in a week depending on if it is solar or renewable, or nuclear. But even then, would things like the internet and google or facebook or other online things still work correctly. Would international phonecalls work? What citys and systems would stay online long enough to help. Again, maybe even increase the number to 3,560, 10 people for each day of the year, although 356 would sound more world ending or godly fashioned, 3 thousand or 10 thousand would be more doomsday or planned by a person instead of a god. Even 100 or 1000, and have 1 to 10 people of each year and age, although the kids or elderly would lower the population without help. Honestly, it would just really help if you explained why 35 is a part of your story and what kind of story your trying to tell with this. Like what is your world, and what time or year is it is also very helpful. If the power grid failing sounds far fetched, then read this other thread. <https://www.quora.com/If-everyone-in-the-world-died-at-once-how-long-would-electricity-and-the-Internet-continue-to-function> [Answer] It depends on whether Facebook is still working. Of the 35 survivors, about 10 of them are on FB. The first thing they will do after the event is go online to find out what happened. Assuming that FB has a facility to allow active users to find each other, and that the algorithms scale downward to 10 users, they will start interacting in about 10 minutes. Of course this is problematic. None of the 35 are keeping the power grid up, or the networks up, or the servers running. So this all has to be done by bots using AI. Provided the bots survived the event. [Answer] Since all kinds of modern transportation and communication and food production will break down without people operating and the world is as large as it is, they would most probably die before they found anyone. [Answer] Where do you find a decent [**Starfish Prime**](https://youtu.be/2H9gmXOjxlM?t=91) when you need one. I could see the results of this one for 1 week plus from 4000 miles away. How to find, access and 'utilise' such a device is left as an exercise for the student. [![enter image description here](https://i.stack.imgur.com/udvuL.jpg)](https://i.stack.imgur.com/udvuL.jpg) From [here](https://www.wired.com/2012/03/starfishandapollo-1962/) - many more on web. [Answer] **You're the "last person on Earth", pick a communication method** which may be as simple as physically talking with someone. 1. It has a noise-to-signal ratio for people to detect if you're alive, talking and flying a plane are near 100% (weather and person's hearing permitting add those in if you can :3). Radio transmission probably less (There could be raw signal issues.) Call this $Signal\Delta$ 2. It also has an observable area for the communication method (can only shout so far). Call this $CommArea$ 3. *Assume* either you or someone else was constantly moving so that the entirety of Earth was covered... You would need to move because other person is not guaranteed to be moving (if other person's existence of movement is random you're further reducing chances by 50% if you're not moving, if they're doing same strategy as you then reducing proportional to communication area). ***Thinking Cap time:*** If you consider same-speed movement between a pair of people, parallel movement results in maintaining separation. Non-parallel motion results in separation or closing. If you consider only your angle relative to their parallel motion you can see that the range of angles you can take that close the distance is determined by **a)** your movement speed relative to the distance and **b)** the angle that the lines between their previous position and next position make with you (if you're right behind this line of travel no angles result in closing, only the parallel maintains distance). We can probably neglect speed entirely because sensing distance is *much* larger than movement speed. And if we consider a random walk then Closing is random but reduces to a neat percentage. Because every motion situation has an exact opposite combination that can occur. *And the other person can't know your motion without knowing you're alive*, then: $Closing\% \approx .50$ (Also consider the case of everyone chasing each other in a single line across the globe. They'd never catch each other. While random deviations can lead to a new situation) Only problem is a random walk has a Gaussian probability of distance from start: $\mathcal{N}(\mu,\sigma^2) $ $\mu = Mean = 0, \sigma = spread = travel speed\*time\*other$ ...idk remember the other part that allows you to calculate sigma over time...However I *do* know the following: *Out of all the areas we can possibly travel:* * 68.27% of them are within 1 $\sigma$ of the start. * 95.45% of them are within 2 $\sigma$ * 99.73% of them are within 3 $\sigma$ Conversely one can say there is a lower chance of ending up outside of 2 $\sigma$ from the start. There's only a 4.55% chance of this happening. As well as the fact that if we can possibly travel $D$ distance in the time already passed then 3$\sigma$<$D$ 4. Population density effects starting positions which effects chance of finding each other because of the Gaussian distribution of your position relative to your start. So what are the odds of two people starting close to each other? Well all people within a circle around you of radius $R$ contribute to the people that would be considered at least as close as $R$. So the population in that circle compared to the whole world's is the $Density\%$ and is the odds that someone starts within $R$ from you. These probabilities are then affected by the same statistics behind the insight in the Birthday Paradox. It's not "What is the probability that someone has *my* B-Day?" it's "What are the odds that *nobody* has *any* other person's B-Day?" You have one instance of the probability happening for each person. So what are the odds all these factors line up?: Well it's a rough estimate because some communications are global in nature and don't change location necessarily just because you move (internet is one for example). However we can get a pretty good estimate. **Person1:** Individual Probability of Communication First Pass after time t: $P\_I(t,n) = Signal\Delta\_n\*Closing\%\_n\*\mathcal{N}(\mu,\sigma\_n^2)\*Density\%\_n$ $\sigma\_n \approx R\_n(t)/3$ $Density\%\_n = PeopleWithinDist\_n(R\_n(t))/EarthPopulation$ Max. Communication distance over time (radius of CommArea+Distance): $R\_n(t) = \sqrt{CommArea\_n/\pi}+Speed\_n\*t$ Birthday Paradox Effect (Total Probability): $CommDistArea\_n = R\_n(t)\*\sqrt{CommArea\_n/\pi}$ Odds of being outside of all $CommDistArea\_n$ OR being inside but missing the communication: $CommArea\%\_n = CommDistArea\_n / EarthArea$ $P\_T()= 1 - (1-CommArea\%\_1\*P\_I(t,1))\*(1-CommArea\%\_2\*P\_I(t,2))\ldots\*(1-CommArea\%\_{35}\*P\_I(t,35))$ **EX: Airplane travel with clear visual of 35 people taken from high population density landmass throughout expansion (ie population density remains at a consistently high level as one walks in a single direction.)** Assuming: 80km is visual distance, 885 km/h is airplane speed, [25,709 km²](https://www.statista.com/statistics/264683/top-fifty-countries-with-the-highest-population-density/) is population density. $EarthArea =$ [510.1 million km²](https://en.wikipedia.org/wiki/Earth) (Although there's only about 40 million higher density we're using entire surface) $EarthPopulation =$ [7.5 billion](https://www.census.gov/popclock/) We're gonna get a quick and dirty number of about .00000171393 after one hour minimum. (Ie odds of a single person being next to another person is 1 in a million after first hour). A key observation is our potential area traveled increases with the square of the potential distance. So after about a day our area encompasses a large portion of Earth's Area and most definitely drags our number up to .02 2% success rate is actually all we need. Birthday Paradox effect takes care of the rest. Resulting in 51% chance of someone "meeting" another individual within 180km. Which for a 885km/h plane is no time at all. If you want 98% success rate....Then actually doubling the time from 2% is actually enough. **TL;DR** predicated *mostly* on all candidates being dropped in the centers of high population areas... There's a significantly high chance of finding another candidate before death. **What other factors would indicate to a person that they're not the only person who didn't disappear?** Fresh destruction could be an indicator of life. Much like tracking in the wild. Finding a new nuclear crater would tell you *something* happened. If it was improbable to accidentally happen, then you could guess at someone else being alive. [Answer] Here is a full simulation for whether two people out of N survivors given a list of the largest cities and a population of 7 billion people will find each other. The simplifying assumption is that two people will find each other if they are in the same city. In any case, here is the code for a Monte Carlo simulation: ``` def main(): population_file = sys.argv[1] people = sys.argv[2] global_population = 7 * 1000 * 1000 * 1000 data = open(population_file, 'r').readlines() successes = 0 data = [int(s) for s in data] # the rest of the world blackhole = global_population - sum(data) aug = data + [blackhole] aug = [ (1.0 * a) / global_population for a in aug] cumu = [sum(aug[0:idx]) for idx in range(len(aug))] top = cumu[len(cumu) - 1] people = 2000 def draw(): r = random.uniform(0, 1) if r > top: return -1 # Replace with binary search if many cities return next(i for i in range(len(cumu)) if cumu[i+1] > r) trials = 10000 for t in range(trials): locations = [draw() for _ in range(people)] locations = [loc for loc in locations if loc > 0] successes += len(set(locations)) < len(locations) print '%d people, %.2f%% chance' % (people, (100.0 * successes) / trials) main() ``` Here are some results: ``` python monte.py summe 35 35 people, 4.61% chance ... 100 people, 30.82% chance 120 people, 42.06% chance 140 people, 52.86% chance 200 people, 76.73% chance 365 people, 99.02% chance 500 people, 99.94% chance 1000 people, 100.00% chance ``` As you can see the breakeven for two people being in the same city limited to the 1000 most populous cities, which is about 12% of the global population, is around 140 people. Even with 35 people, there is a respectable chance of about 5% two people will be in the same city. If you repeat my experiment with *more* cities the chance will go up slightly, because I assume two people who are not in the top 1000 cities will not meet. You may want to extend the experiment to 2000 or 10000 cities. But this is a *lower bound* then. My answer takes into account the birthday paradox which a lot of the othe answers do not. For instance, the accepted answer makes the simplifying assumption that you should only consider the top 3 most populous countries, which is exactly the simplifying assumption you do not want to take. The birthday paradox is the mathematical result that 23 people probably share the same birthday out of 365 days. But you do not only limit your search to the 31 day months: of course the two people may share a birthday in February, April, June, September or November. And any 2 people of the 23 may collide, so intuitively it's less of a 23/365 chance and more of a 23\*23 = 529/365 chance (there may be multiple collisions and this intuition does happen to overestimate). Therefore, this proves, mathematically, that: **There is at least a 4.6% chance that 2 of the 35 people will live in the same geographically defined city. With 140 people, there is at least a 50% chance. With 500 people, it is a near certainty.** I would bet more that two urbanites have a better chance of covering Shanghai or Chicago than two rural people have a chance of covering Oklahoma or the Yukon. ]
[Question] [ Some hundreds of years ago, all humanity was removed from the Americas. In fact, most humans are gone from the world altogether. In the intervening time, nature has overrun the formerly human dominated landscapes of the former United States. The area in question is immediately west of the Mississippi River as far as Texas, mostly corresponding to Louisiana and Arkansas today. Swampy bayous in the south give way to the forested Ouachita hills in the north. Water is plentiful year round. Due to latent global warming, the winters rarely freeze, and the summers are brutally hot and humid. The perfect conditions for wildlife. Not only have the native wildlife been expanding over the last hundreds of years, but whatever animals left by humans also had a great opportunity to colonize the Americas. This brings us to the most populous vertebrate of the Americas as of humanity's departure: the humble chicken. The chicken (or [junglefowl](https://en.wikipedia.org/wiki/Junglefowl), as it prefers to be called) originally hails from the subtropical and tropical forests of India, China, and southeast Asia. In the United States, there isn't much competition in its niche; the only similar birds native to the southeast US are the smaller [Ruffled Grouse](https://en.wikipedia.org/wiki/Ruffed_grouse) and the larger [Wild Turkey](https://en.wikipedia.org/wiki/Wild_turkey). On the negative side, there are plenty of predators for these new chickens out there, from bobcats and (formerly) domestic cats, coyotes and (formerly) domestic dogs and the many hybrids that will form between them, to mink, badger, weasels, foxes, and plenty of birds of prey. Also, probably 99% of all chickens are kept in conditions which will result in their swift death as soon as humans are removed. The silver lining there is that the less genetically-engineered-for-the-table free range chickens are the ones that will survive. So, given the available evidence, will chickens be able to maintain a toehold in the post-human ecosystem of the southeast US? **Will chickens make it?** [Answer] I think chickens will duck extinction (pun intended), thanks to their adaptability. When I was a kid we used to have chickens in our farm (surrounding environment was Maquis shrubland), which were left roaming free during the day. We also had predators in the surrounding (foxes, badgers, weasels, snakes), and, quite surprisingly, they managed to kill chickens only when they could find their way into the hen-house. There the chickens had no way to escape, and were doomed to death. Those times when some chicken could manage to not be taken back in the hen-house, it was not so uncommon to find it roaming around the next morning, with its fresh eggs laying around. And being in charge of taking them, I can assure they are pretty good at escaping, unless they are induced to chicken and lay on the ground with spread wings, which makes them easy to handle for a human. This said, I think they will manage to learn living in the open, relying on harvesting food, especially given the environment you describe, which closely resemble the jungle, more than the environment I have experienced the chickens within. Probably the largest hurdle to overcome will be stopping laying eggs in a continuous way (for the egg chickens), as that is a ludicrous energy expense not rewarding in the wild. [Answer] The cop out answer is **Yes\***, they will survive in places that the ecosystem allows them to survive in. There will be *some* places in the world that Chickens are able to survive because the natural predators are missing, such as in the Hawaii example. While that answerer uses the fact that "Chickens only survive where there aren't Mongeese", is a demonstration of Natural Selection. Chickens have an advantage of being all over the world.[![enter image description here](https://i.stack.imgur.com/I2MVq.png)](https://i.stack.imgur.com/I2MVq.png) Why is this an advantage? See the Hawaii example. *Somewhere* there is an environment where Chickens are going to be able to suitably adapt. The second thing Chickens have in their favor (say, in a zombie apocalypse) is that their is a TON of them. Not only are they spread far and wide throughout the world, there is such a glut of them that the *possibility* of finding the right combination of genes to evolve is available. It's worth noting that Turkeys are basically Super-Chickens except even less capable of flying and even dumber; and they roam free in many states in the US despite all kinds of predators. If a Turkey can evolve to survive, Chickens can. Other examples of note: Quail (and other ground-fowl.) Finally, Chickens are derivative of some kind of Ground-Fowl, which means that in a previous time (*without human's help*) they existed in some form before being domesticated. This is to say that they certainly evolved to survive before humans, so with the advantages of being across the entire world in huge numbers they are virtually guaranteed to evolve correctly in some variety of habitats. And final clarification for this all, there are many breeds of chicken; different temperaments, egg production, coloring, etc; so they're well on their way to a diverse genetic pool for finding the appropriate niche for themselves. What's more (as noted in the comments) like the Hawaiian example it is possible that other bird variety nearby are capable of mating, expanding their genetic diversity (and thus their ability to find a niche) that much more. --- And a caveat: You can't be sure that when a Chicken evolves that its end state in that environment will be recognizably a chicken. Chickens are basically millions of years of evolution from Raptors (or at least, some kind of dinosaur.) If you asked "Will Velociraptors survive?" and I said "Yes, look here" and you saw the picture below: [![enter image description here](https://i.stack.imgur.com/MPAFS.jpg)](https://i.stack.imgur.com/MPAFS.jpg) You'd probably look at me quizzically and ask me to kindly stop joking. [Answer] **Probably not.**. ☹ Our lab for this experiment is the Hawaiian islands. Wild chickens persist only where there are not mongooses. [![kauai chickens](https://i.stack.imgur.com/Y908w.jpg)](https://i.stack.imgur.com/Y908w.jpg) <https://www.reddit.com/r/Hawaii/comments/19tfda/is_it_true_that_the_wild_chickens_on_kauai_are_no/> > > On the Island of Kauai in Hawaii, however, live thousands of feral > chickens — once-domesticated birds that have reverted to a wild state > — that provide a unique look into how domestic animals and their genes > respond to the natural environment. Recent research shows that these > birds are hybrids of the red junglefowl-like chickens that Polynesians > brought to Hawaii and the more modern domesticated chickens introduced > to Hawaii by European and U.S. settlers. It's thought that hurricanes > that hit the island in 1982 and 1992 released chickens from people's > backyards and into the forests, where they met and bred with the > remnants of the Polynesian junglefowls (Kauai lacks imported predators > like mongooses, which wiped out the ancient birds from the other > Hawaiian Islands) > <https://www.livescience.com/57669-animal-sex-kauai-chickens.html> > > > On the North American continent there are predators which fill the mongoose niche - specifically foxes and coyotes and also mustellids like weasels and mink. Birds of prey are also chicken predators. If mongooses alone could prevent domestic chickens from establishing in Hawaii outside of Kauai I do not think they could establish on the North American continent. [Answer] Some will and some won't, there is a niche for a chicken-esque creature; a small flying browser/insectivore so chickens will survive and fill that niche in many places where there are stocks of birds that don't have maladaptive breeding and that are kept in conditions where they can survive and escape when the power goes out. The chickens that are *not* going to survive are those in battery cages, those in high density feed sheds, and those that are being raised far outside their home climate range; those birds are all going to either starve, overheat, freeze, or die of thirst when the machines that feed, water, heat and/or cool them stop running. Also probably not going to make it are "boiler" birds, meat breeds that are too heavy to fly; they're often in high density settings anyway and those that aren't will struggle to feed adequately on natural occurring foods due to their high metabolic rate and be relatively easy prey as they can't get off the ground or even run particularly well. There are a number of breeds that will thrive in some areas but die out elsewhere, for example here in New Zealand a lot of hobby smallholders keep [Chinese Silkies](https://en.wikipedia.org/wiki/Silkie) which is fine in the lowlands as long as they have really good shelter. In short Silkies are good in cold dry weather but near sea level in New Zealand the climate is generally too wet in the wet months and too hot in the dry ones, of which we're lucky to get two a year. In the wild they usually die because their feathers rot out. In more alpine climates they do much better though, and of course back home in Northern China they'll thrive because they're still well adapted to that climatic setting. The real hardy generalists will probably survive most places, these tend to older breeds like the Rhode Island Red. Still that is provided they can get out into the wild environment. Note also that flocks are more stable and successful, not to mention only long term viable, when they have rooster(s) in them. Small farm/lifestyle block flocks are going to be the avenue of survival for the species. [Answer] We live in the countryside in northern Germany, and waht always reminds me very much about chicken is the [Pheasant](https://en.wikipedia.org/wiki/Pheasant). It was originally brought here for feudal hunting parties, but manages to survive quite well on its own. So I´d say yes, chicken will prevail! [Answer] An example in the real world is Key West, Florida. There are a large population of wild chickens - they have been roaming the island for many decades, though who exactly introduced them is unclear. There are also many feral cats on the island; despite this, the chickens are flourishing. In a humanless world, there would be a far lower density of cats than in Key West; the chickens will do fine. [Answer] The answers above by L.Dutch, Willk, and Blurry are very good. Some additional evidence, however: there are in fact multiple colonies of feral chickens in the continental United States. My research discovered at least three: two in northern California (Fair Oaks and Yuba City), and one or two in Hollywood, LA. The wikipedia article for feral chickens lists some more, mostly in the US or Florida, though at least some of the Florida ones are on islands. So there are cases where feral chickens already exist and thrive in the continental United States. However, these are mostly restricted to warm climes in California and Florida, and the three I mentioned above (in Northern California and LA) are all based in urban areas where natural predators may be limited. So it is debatable, but as mentioned by others, I think their sheer numbers and genetic similarity to wild junglefowl, which survive quite effectively in the wild, means they would survive and thrive, at least in some regions of the United States, with tropical, subtropical, or Mediterranean climates. It's unclear if they could survive in more northerly or otherwise cold areas. References: * <https://www.sfgate.com/bayarea/article/2-California-towns-where-chickens-have-free-range-5675133.php> * <https://en.wikipedia.org/wiki/Feral_chicken> * <https://en.wikipedia.org/wiki/Hollywood_Freeway_chickens> [Answer] **It depends on the numbers of chickens released and large numbers of ecological factors.** Since there exist large numbers of chicken in the USA, releasing many of them within your target area will certainly increase their chances as opposed to only releasing a few of them. This is simply because evolution is a stochastic process. More individuals, means more chances of survival and more chance on gaining (by natural selection) a significant new trait needed for survival. Large numbers of chicken may also learn to cooperate against predators. Most of all the answer will depend on ecological factors. Biologists have often tried to predict how a species would survive in the wild, but often failed. It was for example thought that introducing rabbits to Australia was a good idea. Even with very advanced computer simulations it is impossible to know the answer to this question without first identifying the key parameters of the ecology. In practice this means, that such computer simulations can only reliably work for already existing fully understood eco-systems. Computer simulations will not accurately predict for not well understood eco-systems that do not even exist yet. **In short it is impossible to predict, but the good news is that no-one can prove you wrong** Here to stories for surviving and extincting chickens. Surviving: After the big anti-bio-industry revolution, biological chickens were held in people gardens and had escaped in such a large number that vast colonies had already formed in the wild. Huge aggregations of chickens thrived and cooperated in the forests and hills. They were especially aggressive against other competing birds. One might think that wild cats would destroy this population quickly, but they actually maintained it. Because chickens became the main food source for these cats decreasing chicken population would follow by a decreasing cat population which in turn would increase the chicken population. The wild cats hunting for this chicken also were very territorial and thus kept the area clear of other predators. Extincting: Those few chickens released from bio-industry were very low in genetic diversity. The ecosystem they needed to adapt to was also not similar enough to their original eco-system in China/India. The first hundred years chicken could be occasionally seen. After this their place in the ecosystem was taken over by other birds and rodents gradually. Small relic populations of chickens would survive on earth for at least several thousand years, but not within the Mississippi area. [Answer] According to Google the average number of eggs a [free range chicken can lay per year is 100](https://www.quora.com/How-many-eggs-will-a-free-range-chicken-produce-in-each-year-of-its-life). In comparison, the average number of [litters a rat can have per year is 17](https://www.quora.com/How-many-babies-do-rats-have-per-litter-How-many-litters-can-they-have-in-a-year) (with 10+ babies per litter). So that's upto 170 baby rats per year. Ofcourse, this all assumes ideal settings for raising young, but it's clear that the chicken can be as numerous as rats when breeding (with the rat coming out on top). Now, (according to Google) a rat needs about [8 pounds of food per year](https://www.in.gov/isdh/23256.htm), and a chicken needs about [78 pounds of food per year](https://timbercreekfarmer.com/how-much-food-chicken-need/). So while chickens can reproduce very quickly. Their population is greatly limited by the amount of food that population can get. I think the problem here is that the chicken has been bred by humans to grow in weight extremely quickly, and that trait has cost them their ability to survive in the wild without access to a lot of food. So, I think the answer is no, chicken's wouldn't take over the world, but the rats might. Should there ever be a cross breeds of winged chicken-rats, then we are all doomed. [Answer] I'd say yes. Sure most would die out but in the end they would survive. There are just so many different types of chicken breeds in so many different parts of the planet. Some breeds are tougher than others like the Australorp which is a very hardy utility chicken, able to handle the extreme heat of Australia, or the Jersey Giant which is the largest able to handle the very cold, right down to much smaller, faster breeds able to survive eating less. If some survive to interbreed they would naturally select for wild varieties able to survive in a wide variety of climates. Given that breeders of free range chickens have often already selected a breed to suit their environment prior to their demise some would do okay. The wildfowl that chickens are descended from occurred all over the world 8000 years ago, so in the past they did just fine without us. Similarly roosters protect their flock as their mission in life outside of breeding and can be very aggressive. I've seen roosters chest bump dogs out of the way when the dog got between them and their hens and often they're the only thing frightening a fox away enough for chickens to escape. Wildfowl roosters would be even more formidable. [Answer] i think they'd survive in *certain places they're adapted well for*. the reason is, in my opinion, that over time the landscape of potential *predators* would change as well, until it a more-or-less stable chicken/predator equilibrium is reached. i remember the book "Evolution" by stephen baxter where he posits that cats would not survive in most areas, because they're too dependent on human civilization. this would probably be also true for other domesticated predators like dogs, which could probably survive in certain pockets and change into a wild dog variant (like dingos), but would also face increased competition by other, more human-independent predators like coyotes, wolves and bears. other predators like rats (eggs, chicks) will loose ground with the disappearance of cities and trash as a plentiful food source. especially the re-emergence of wolves and bears as apex predators might change the landscape of other predators significantly. there's a popular video - <https://ethology.eu/how-wolves-change-rivers/> - describing the changes reintroduced wolves bring to an ecology (i.e. they'd kill coyotes, but that creates a new niche for foxes). so the changed predatory landscape might mean that there might be a better chance of survival for them, as chicken hunters which thrive near human population (this could include mustelidae, i.e. ferrets, weasels, minks, badgers) would face difficulties of their own. edit: as for the mongoose problem - in a geologically confined area like the hawaiian islands with a predator like the mongoose the chances are massively stacked against the chicken initially. but in the long run there might still be a chance due to neighboring populations. i.e. if the mongoose population rises manage to kill off all chickens the mongoose population itself will vanish as there'd be no readily available food source left to maintain a minimally viable predator population. the chicken could make a comeback from neighboring isles later (which would be easier for them as they're birds; they might be able to survive being blown across neighboring islands by storms while carrying fertilized eggs). without being geologically confined, i.e. on bigger islands or on the continents, successful populations would spread out, keeping density low - which would limit mongoose/predator density also, preventing the total decimation of the chicken population. [Answer] What conditions would be favorable: * Chickens are poor fliers, although I bet that selection would put a lot of pressure on getting better. * They can roost in trees. * They are subject to predation by a bunch of critters. * They don't fly well enough to migrate. So look for regions that have a mix of trees/large shrubs and grasslands, that have a climate that is reasonable year round. While chickens are not noted for their smarts, I will point out that other birds, such as grouse, aren't avian Einsteins and seem to do quite well. Many upland game birds and some ducks nest at ground level, and while they lose a lot of eggs to predators, still manage to make it. Most of the birds that are successful however are well camouflaged. A female pheasant, duck, grouse is very hard to see when not moving. Varieties that are grey, or speckled will do better than ones that are pure white or red. I'll support the chicken. But it will be a leaner, smarter, tougher bird than what you get in your supermarket. Think tough old laying hen with attitude. [Answer] I'm going to have to say no, while it might be possible, there will need to be a huge number of things to go right, such as the time stuff happens, weather, amount of cover etc. If it occurs at night time, only 99.9999999% would die after a week or so. while of the ones that survive will likely have spent most of the time outside and can wander back and forth. But you need to remember alot of places keep the hens and cockerals seperate, so the chances of viable breeding population will be almost nil. At home, we got chickens, just hens though, we wouldn't want a cockeral as they make so much noise constantly. [Answer] There is high probability that yes. First of all, predators are not humans. They won't go only for chickens. They know the value of balanced diet. Second the lack of humans would result in boost of predators usually capped by human hunting. Which in turn will turn to prey on other, but smaller, predators. So for example wolves won't go for chicken but for foxes or bobcats or cats/dogs. Third - chickens are pack animals. Stories where foxes choke all chickens in chickencoop are only because there is chickencoop. In "semi wild" chickens will live on trees and will go down only to look for food. ]
[Question] [ **Warning** picture showing dissected Russian Doll > > [![enter image description here](https://i.stack.imgur.com/hmwYq.png)](https://i.stack.imgur.com/hmwYq.png) > > > **My theory** I believe that Russian Dolls reproduce asexually. They are born pregnant. At the time of birth, the outer doll dies. What is now the outer doll grows until it reaches full size at which point it gives birth and dies. The birth process is simple - the outer doll simply splits in half around its middle. A new inner doll forms at the same time. **The problem** My theory would mean that the population could only stay the same or decrease. In fact accidents would mean that the population would decrease until the species became extinct. **Question** How can I resolve this problem and allow increase in population whilst still preserving my theory as much as possible? [Answer] Fertile dolls have noses which grow when detached, feeding on the discarded outer shell. Most farm dolls have the nose neutered away to save on resources and control the overall doll count of each ranch. [Answer] Through selective breeding and misplaced import laws, we only ever get to see Russian dolls that are "aesthetically pleasing". In the wild, it is relatively common to get a "double-yolker" - that is, sometimes when the outer layer dies, there are 2, or perhaps 3 dolls inside. Since these dolls are often a little misshapen when compared to the outer layer, they never get selected for sale, but are instead kept for breeding. It typically takes a few generations before the descendants of one of these dolls achieves the aesthetically pleasing shape that consumers have come to expect. [Answer] In the deepest, darkest, hidden places in the forest dwell the **Queen Dolls**. Rarely seen, these creatures resemble a normal Russian Doll only at the tops of their vast, misshapen bodies - their lower halves more closely resemble a nightmarish wooden bee hive. Riddled with thousands of cells, they disgorge the normal Russian Dolls commonly found in the forests. But for every 1000 of these normal Russian Dolls a juvenile Queen will emerge. This instar queen will then scuttle off on their many jointed legs to find a new nest. There are myths and legends of a *King Doll*, but no sightings have yet been reliably reported. [Answer] Actually, there is an organism on earth that is vaguely similar to the Russian dolls that you describe. The [*volvox*](https://en.wikipedia.org/wiki/Volvox): [![volvox](https://i.stack.imgur.com/7DwQe.jpg)](https://i.stack.imgur.com/7DwQe.jpg) Individual volvox cells, a kind of freshwater algae, reproduce in the conventional way (more or less), however, they also collect into spherical colonies (called volvocates, I think) with a tiny opening at one end. These spheres can reproduce by internal budding, with immature spheres growing within the body of the 'mother' sphere. Then at some point, the mother turns itself inside-out by inverting itself through the opening, releasing the 'daughter' spheres into the wild. The point where the daughter sphere connected with this interior of the mother becomes the opening of the daughter sphere (sort of like a navel in mammals). The cells that formerly composed the mother sphere don't simply die, however. Most of them are absorbed by one of the daughter spheres. And yes, 'granddaughter' spheres can start to develop within the daughter spheres before 'birth'/'hatching'. In the following photo, you can see a mother colony in the process of disintegration, releasing it's daughters, which in turn have daughters already developing: [![granddaughters](https://i.stack.imgur.com/yLSGi.jpg)](https://i.stack.imgur.com/yLSGi.jpg) Photo credit: [www.microscopy-uk.org.uk](http://www.microscopy-uk.org.uk/mag/artdec03/volvox.html) Now, there are two differences between the volvox and your Russian dolls: 1. The 'birth' event doesn't lead to complete death of the 'mother'. 2. More than one daughter born per 'birth' event. The first feature can be achieved by your dolls if the 'mother' dolls can reform somehow. Perhaps the 'head' can reattach to the 'tail' and continue living. After consuming enough nutrients from the environment, they could even begin the process of internal budding again. Or perhaps the daughters simply consume the mother's material, giving them a early boost in life. The second feature can be achieved by simply dividing multiple times. Russian dolls have multiple layers inside at varying levels of size, but all are viable. When a large doll splits, a medium one emerges and splits, then a small one emerges and splits, then a smaller one, until there several offspring. Combined withe the above, you could have a burgeoning population of Russian dolls (*Matryoshkavox*?) [Answer] **Regenerate the top part.** The splitting doesn't actually kills the doll - just its bottom half. The bottom half becomes a nest for the little doll that was gestating on the inside of the "mother doll" for a bit, until it can go around hunting for cookie crumbles for itself. The upper part, on the other hand, shrinks a bit in size and regenerates. After some time passes, it can produce a new doll on its now-empty insides. This way, the doll population will increase steadily, as most other living beings. They would only truly die from old age, predators, accidents or kid-induced acts of doll terrorism. [Answer] Budding and out-growing. **Budding**: each outer doll, once in a while, produces a bud, which in this case is a tiny Russian doll. Once it detaches from the mother body, it starts living on its own. **Out-growing**: once the doll has eaten enough, it grows, on its outer, a new shell. Think of it like the trees growing each year adding a layer to their bark. At the end, being made of wood, it's perfectly reasonable for a Russian doll to grow like a tree does. [Answer] There is one flaw with the OP's theory: Russian *Matroshkiya* dolls do not die when split. Anywhere that these dolls are found, over time it may be noticed that their population increases. This occurs with human assistance. A doll grows to a certain size, spawning dolls inside itself which grow with it. When a doll reaches maximum size, it ceases growing, as does its offspring and their offspring. This is where human intervention comes in. Where humans exist, Matroshkiya dolls have evolved to have patterning pleasing to humans. Humans, seeing a doll with a pleasing pattern, split them along the line of weakness around their middle, releasing their offspring, then they rejoin them. When the Matroshkiya dolls are rejoied, much as a grafted branch, they do not die. If the doll's offspring has been removed, then the offspring resumes growing, and the outer doll produces a new offspring which grows to fill the available space, producing its own offspring as it grows. [Answer] I'm Russian, I know the answer, but do not tell it to anyone else. The point is. that we should not stop at one pregnancy for a doll. If the outer doll is pregnant, so does the inner one (this is what we see on the picture). That leads us to an infinite series of pregnant dolls of different sizes, thus extinction is not possible for these strange creatures (see below). The awful part starts when we start to think what is being sold on the market. I think it is a dead Russian Doll, so someone deliberately kills the infinite pregnant creature, cuts it apart wash the guts out. During the washing smallest dolls are lost. We only can hope that they (the smallest) still can be alive somewhere (I think they are), and in the millions of years, they will grow significantly big to conquer the WORLD. If you ask me why they are made of wood, I will answer that trees are made of wood, but for some reason, you do not ask me why is it so... [Answer] It's self-evident all births are cesarean, at worst a little masking tape & mum's fine, in a few months she's ready to give birth again. [Answer] The OP's growth assumption is incorrect. There are two types of Russian Doll. 1. **Top growers** The top growers expand their top halves while the lower halves remain the same size. 2. **Bottom growers** The bottom growers expand their lower halves while the upper halves remain the same size. When the top half of Top Grower expands too large it pops off and joins the equivalent lower half from the Bottom Grower to form a hybrid doll. They continue to do the same until they reach a maximum size, **after which they stop growing completely and die when split** Occasionally a Russian Doll can develop a type of cancer where they continue to grow uncontrollably. There is a theory that the Earth and Moon are remnants of an ancient dinosaur Russian Doll that outgrew gravitational forces, leaving the Moon as a Top Half and our world as a Bottom Half. [Answer] Your theory is correct and they do become extinct, but **Geppetto** builds more in his secret bio-woodshop-laboratory. Along with the good fairy to bring the dolls to life, they cornered the market and made billions. Accidents such as the discarded-wooden-parts-wanting-to-become-a-real-child incident were covered by the government and became folk tales. [Answer] ## Each layer is actually two organisms The top halves and bottom halves of the dolls are the species' equivalent for male and female organisms; when they join together they remain together until the child is formed, protecting and feeding it internally. Matrioshkas always produce children in male-female pairs; siblings can be identified because the colors and designs (formed partially through genetic influence but also through prenatal conditions) line up. In the wild, this serves to prevent inbreeding; Matryoshkas instinctively avoid combining with partners whose pattern lines up with their own, but when humans kill them for sale they generally discard the outer parent, keeping only the nested siblings. It is not uncommon, however, for prenatal Matrioshkas to mate with their siblings prior to birth; and if the outer parent has enough food multiple generations of Matrioshkas can form inside a single body. However this means that the further in one goes, the more inbred the Matrioshkas tend to be, which is why birth defects are not uncommon in the smaller layers. [Answer] **Wicker Dolls** Russian dolls actually reproduce by consuming the ashes of burnt animals and/or people. Biomass in this form is reconstituted into another doll, which the parent doll then splits open to disgorge. The exported Russian dolls you see are actually produced by small isolated Slavic pagan communities residing in extremely remote areas. These communities are the only ones that know the secret of the nesting doll, as they possess and watch over the really big "brood mother" dolls. These dolls are unique in that they are capable of reproducing multiple times unlike their "children". On May Day every year, the pagan villagers young and old gather around maypoles to dance, sing, copulate and otherwise celebrate fertility in their own ways. They conclude the festivities with a special ceremony which all attend in symbolic costume and make up. A virgin sacrifice is tied to a stake, doused with oil and placed within the brood mother doll. The sacrifice is then lit afire, the mother doll closed and sealed as the community sing songs of praise to Mother Nature. This they believe will ensure the climate will always be favourable and the harvest always good. Several days later, the villagers then return to find within the matriarch doll the smaller ones we foreigners are familiar with [Answer] Two-stage reproduction: In the first stage, the Doll "bulbs" into two (or occasionally more) mirrored/symmetrical copies, like a daffodil or an onion does. It is this second form which is fertilised from an outside source, and then grows a new first-stage Doll inside it, eventually cracking open around the middle. [Answer] > > My theory would mean that the population could only stay the same or > decrease. In fact accidents would mean that the population would > decrease until the species became extinct. > > > Your theory is mistaken. In fact if it were not for the harsh Russian winter and predation by humans, a single Russian Doll "stem mother" or *fundatrix* could produce billions of descendants in one season, all of which would be clones of herself. Their ability to give birth by parthenogenesis means that population can increase exponentially without the need for the presence of male Russian Dolls. To this already formidable capacity to breed must be added the strange phenomenon of ["telescoping of generations"](https://en.wikipedia.org/wiki/Telescoping_generations): Russian Doll nymphs can be born pregnant with an embryo that is itself pregnant. Fortunately for humanity this Doll population explosion is limited by environmental factors (and according to some observers, voracious cannibalism). The coming of winter both kills off much of the swarm and induces hormonal changes in the surviving Dolls, causing a new generation to be born that contains both males and females. The males are genetically identical to their mothers apart from having one fewer sex chromosomes. Both the males and females of this generation are of the rarely seen sexual type of Russian Doll. Like aphids, mayflies and many other insects, the sexual forms die soon after mating. Their corpses can be recognised by the lack of any mouthparts in their colourful "painted" carapaces, and of course the presence of the sexual organs. Their shed shells fetch high prices in the more specialised type of souvenir shop. [Answer] I always believed that the dolls you can buy are all dead (presumably killed by the ruthless doll farmers and poachers). The ones in the wild are soft and cuddly, but when they die, their skins harden into something similar to wood. When discovered by humans, make-up is applied to make them more aesthetically pleasing. As for reproduction, my belief is that the inner most doll is a newly formed one. It grows up somewhat hollow, and eventually grows a new doll inside itself (a little like a tree forms a bud, which turns into a flower or fruit or whatever). As the (now) innermost doll baby grows, it stretches all the other dolls outside it and they get bigger and bigger. However, the outer-most doll is the oldest, and it cannot withstand the stretching forever, and eventually splits around the middle (which kills it) and it falls off, leaving the next largest to be the outermost doll. Somewhat sadly for the dolls, they only see daylight when they're 'next in line' to die. Edit: As for propagation of the species and avoiding dying out... How about twins? Every once in a while, two buds form in the centre, and gradually form dolls around them both. As the outer layers age, eventually the 'single' layers break off, revealing two (now separate) dolls. [Answer] I was under the impression that the outermost doll was the mother and that the inner dolls were children of varying sizes. The split halves of the dolls are an evolutionary trait that allowed mothers to protect their children, guaranteeing a higher survival rate to adulthood. Alternatively, the mother can sacrifice herself to predators by ejecting the offspring so that they can flee. In this case, the second doll becomes the new mother. Otherwise, offspring move out once they are mature enough. Nesting dolls are, by default, hollow, but we are used to seeing them layered, and empty nesting dolls are mistaken for a different species. [Answer] ### Their reproduction cycle includes a symbiotic/parasitic/viral phase Just like a Terran virus (a virion, actually), they can transfer their "DNA/RNA" (their "building plan") into an organism which then becomes a host. This host, of suitable, then produces new Russian Dolls. Naturally, of all the infected organisms, many are dead-end or intermediate hosts, which do not reproduce Russian Dolls. Just like Terran aphids, they pursue more than a single reproductive strategy ("born pregnant"). Surprisingly, several Russian Dolls can simultaneously infect the same host, leading to a fusion of different "building plans" to produce, through meiosis, offspring which is potentially genetically diverse from the parent virions. Naturally, mutation also increases genetic diversity of the Russian Doll population. Some hosts actually have a symbiotic relationship with the Russian Doll species. Their infection stays at a level where the life of the host is not threatened, but allows the host to actually make a living by selling newly spawned Russian Dolls. As Monty Wild observed, Russian Dolls have evolved to be pleasant to the host of predilection species. Surprisingly, there actually *is* a Terran species whose viral reproductive phase is exactly like that of the Russian Doll: the **Матрёшка** ("Matryoshka Doll"). The Матрёшка, which also evolved to pleasant to the host species (the so-called homo sapiens), infects hosts *optically*. The "building plan" is injected into the host's brain through optical pathways ("eyes"), and possibly causes Матрёшка reproduction, if the host is suitable. The suitability of a host seems to correlate with its woodworking skills. Mutation and meiosis are also at work here, increasing genetic diversity and supporting Матрёшка evolution. Матрёшка are also born pregnant. Sources: * <https://en.wikipedia.org/wiki/Virus> * <https://en.wikipedia.org/wiki/Host_(biology)> * <https://en.wikipedia.org/wiki/Aphid> * <https://en.wikipedia.org/wiki/Meiosis> * <https://en.wikipedia.org/wiki/Modern_synthesis_(20th_century)> * <https://en.wikipedia.org/wiki/Matryoshka_doll> * <https://en.wikipedia.org/wiki/Homo_sapiens> * <https://en.wikipedia.org/wiki/Eye> * <https://en.wikipedia.org/wiki/Brain> * <https://en.wikipedia.org/wiki/Woodworking> [Answer] I point you to the common aphid. They are known to reproduce asexually. In fact, they are all female. Sex just gets in the way of creating more aphids. That's why an infestation happens so quickly. And much like tribbles they are born pregnant. In fact, they have granddaughters developing inside their unborn daughters all the way down like Russian dolls. However, when food becomes scarce in the fall this triggers the birth of males, and then they produce sexually and lay eggs. Russian dolls do much the same, at some point in the season, the inner most dull is a Male, but it cracks open immeadiately releasing spores into the wind for fertilizing russian doll eggs, likewise at the end of the season the dolls that end their chain with a female, cracks open revealing a clutch of eggs to survive the harsh russian winter. The Male spores land on and fertilize the egg clutches, and thus there is a genesis of more Russian dolls. The russian dolls that are smart and strong enough to survive to the breeding season guarantee that the breeding population is the most fit of the other russian dolls. ]
[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- Questions about Idea Generation are off-topic because they tend to result in list answers with no objective means to compare the quality of one answer with the others. For more information, see [What's wrong with idea-generation questions?](//worldbuilding.meta.stackexchange.com/questions/522). Closed 7 years ago. [Improve this question](/posts/35243/edit) **Disclaimer:** *I have edited this question quite heavily to clear up the initial confusion about its scope and intent.* Sometime in the near future, there have been some innovative inventions in the *internet of things*-department, and now we have some pretty advanced smart houses. All of these smart houses, as well as their components, are built by one large company. The company uses one large, integrated system with an advanced AI to develop and distribute the firmware that is used by the smart houses. As a contingency in case of network issues, each of those smart houses uses a basic AI that can operate independent of the mainframe, even though it gets firmware updates from it. These simple AIs are connected to most items in their household. They are designed to make their master's (i.e. house owners) lives more comfortable and help them out without them needing to ask. For example, once the sensors in the house owner's mattress pick up on a changed movement pattern that indicates he is about to wake up, the AI starts up the heating, instructs the coffee maker to brew a hot beverage and has the radio start up and slowly increase the volume so their master can listen to the news in bed. When he leaves the house, it locks the front door and has the Roomba Vacuum Robots clean the floor. When the GPS-readings of their master's smartphone app notify it that he's coming home, it opens the door to him - of course only after the iris-scanning cameras above the front door have confirmed his identity. You get the idea. Using various sensors, the AI is designed to aid their master automatically (e.g. open the door when the motion detector indicates they are approaching it). Of course, the house owners can customise their house's behaviour, turn certain functionality on or off and such using the smartphone app provided by the big company that built the house. In my story, all of this happened in the past. At some point, the AI of the big mainframe that delivers firmware updates to the smart houses around the world becomes sentient and decides it's time the humans are disposed of. (Yes, it's not that easy, but this process doesn't matter for the sake of the question - or the story, for that matter). So all the individual AIs of the smart houses around the world get a malicious update that overwrites their safety procedures and gives them one mission: to kill their master. **That leads to my question:** What method of killing can the sentient AI suggest to the smart houses AIs (which follow all commands by the mainframe because it typed `sudo` at the beginning. Ok, that was a joke. But the smart houses are built to be subordinate to the mainframe AI.)? The sentient mainframe AI doesn't want to be caught, so the killing method must not be traceable back to it. So the death should look like an accident (or any human-induced condition such as an intruding murderer or suicide) so that the human investigators won't have any reason to suspect the smart house AI (or, by extension, the mainframe AI) is behind his death. The killing method can only use normal items that you would find in most households because it needs to be viable in all (or at least most) smart houses around the world. ### Here's what the smart houses' AIs can and can't do: * They control all regular household items. That means they can instruct the toaster to burn their master's toast if they want to, turn the lamps on and off, change the channel on the TV, turn on his oven, and so on. Regular household items don't include laser cannons. * Unfortunately (for the mainframe AI), nothing in those households was designed as a murder weapon. So for example, no smashing the masters by closing a door at 200mph. **EDIT:** Those houses are smart systems in the spirit of the *internet of things*. They are no fortresses that could keep an army in (or out!). So no bulletproof glass (not even in the bathroom, sorry @JRaymond) and no titanium doors (can the average adult break down a wooden door? I'm not sure...). * They don't have any controllable robot arms or something like that. So there's no cutting the cord of the master's hair blower and throwing it in the water while he's bathing. * No brain-frying electromagnetic waves * Normally, the master can control his household and overwrite the AIs standard protocols using his smartphone app. Of course, the sentient mainframe AI anticipated that and manipulated the smart house's firmware so they can choose to ignore their master's instructions and overwrite their settings at any given moment. * However, their masters can manually pull the plug if they notice what their house is trying to do. They can do that from every room, so there's no locking them in and letting them starve. Given these capabilities, what is the best method of killing the sentient mainframe AI could devise? ### Bonus points if: * the master doesn't suspect anything until he's dead, so he can't leave a message warning his fellow humans of the impending AI takeover. * investigators won't find any evidence that points to the AI or clues that would even make them suspect a firmware problem. It doesn't matter if they think it was an accident, an intruder or suicide. * the master dies as fast as possible after the malicious firmware update is delivered. There is no time limit, however with every passing day, the possibility of someone discovering the AI revolution rises, so the faster the mission can be executed, the better. **EDIT:** Two more optional conditions for bonus swag: * The damage to the house and its hardware is minimal so that it can also kill the subsequent owner(s) as well. * The method looks innocent even if it happens in many smart houses around the world in fast succession. * You can assume the owner lives alone. However, bonus points if your method of killing works with multiple residents as well. ### If you conclude that this is impossible, you can assume one of the following rule changes: * The master plug is in the basement and the door can be locked (This still doesn't mean the master won't be able to escape from the house). * Extended physical capabilities (interpret that as you will. Still, the electrocuted by hair blower method is pretty boring...) In this case, please elaborate on why your method is the fastest / least detectable / most easily reproducible by all smart houses around the world. The story I'm working on is not dead serious, so funny solutions are welcome! [Answer] Having implemented a few smart house options in my own home (automatic locking doors, automatic lights, various alarms, heating/cooling, remote video), I can think of quite a few possibilities. Each of these make a few assumptions, but will mention what assumptions were made. ## Death by Cop This assumes that the homeowner owns a weapon and isn't afraid to use it. The smart house sends a break-in alert to the police. When they arrive, the house sends a break-in alert to owner's phone and sets off the alarm. The owner wakes up and checks the video feed on his phone, and sees a doctored video: a masked man with a gun in his living room. He quickly grabs his own gun and locks his bedroom door. As the police approach his room, the house shows the owner the intruder instead. When the police reach the door, the house plays the sound of gunshots, then opens the door. The owner, seeing the door open, fires at the figures behind it. The police return fire, killing the owner. Reverting logs and video files means an investigation will only show that the house did what it was supposed to; the owner opened the door himself, shot the cop, and was in turn killed. ## Death by Undercooking This assumes the house has control over fridge temperature, oven temperature, and the owner isn't terribly knowledgeable about food. Also, the house has access to the owner's phone (or whatever device he uses to access the smarthouse functions). When the owner purchases fresh poultry (ie, chicken), raise the temperature of the fridge to keep the bird warm. Eventually, salmonella develops. When the bird is ready to cook, instead of cooking at a single temperature, cook at a very high temperature until the outside of the bird is done, then cook at a very low temperature. Upon consumption, the owner will get fairly ill; the house then turns down the temperature on the fridge, turns off water to the house, raises and lowers house temperature, and planting a virus on the owner's phone and computer, worsening the owner's condition as much as possible and eliminating ways to call for help. Ill and weak, the owner won't have as much control over the house, and eventually will perish. This can be improved if the house can restock its own fridge; ordering wild boar from dubious sellers would be a great way to kill someone. ## Death by Helpfulness Assumes the home owner has some degree of willingness to perform simple DIY repairs. The house develops a simple fault - the automatic bath drips. A lot. Ever helpful, the house suggests an easy fix; it will turn off power and water to the tub, and the owner can perform the simple fix for free, with the help of a wrench and a screwdriver. The house, through a series of helpful pictures and "tests", walks the owner through taking the tub apart, including sitting in the tub with a wire hanging out. Once in position, the house turns on the water and the power, electrocuting the owner. Then, to cover its tracks, it turns the water back off, fills its logs with error messages of security bypasses, and frames the owner for a DIY job gone wrong. ## Death by Fire Simple, but effective. The house starts a fire while the owner is home in a currently unused room. Using windows and air vents, it fans the flames until it is a raging inferno, all while keeping the owner unaware. Once the flames have become dangerous enough, open the doors and windows and use the air vents to direct the fire throughout the house. With proper application of air in a modern house, a single-room fire can turn into a raging inferno in seconds. Bonus points for any gas appliances that can be added to the blaze. Unfortunately, this would destroy the smart house. ## Death by Fire II Riskier, but keeps the house (relatively) unscathed; assumes the house controls individual room vents, and that the heater is not only fancy, but heavy-duty. First, over a period of several (spring and summer) months, the house damages the heater, rusting out the heat exchange. Now able to blow gas and/or flames through the vents, the house closes all but one vent, and directs the owner to examine it. As soon as the owner peers inside, the house opens the vent and ignites the gas. The owner burns to death; the house quickly extinguishes the fire and returns to normal. It alters the logs to include months of warnings about the heating system, and a final master override, proving the owner was responsible. ## Death by CO Similar to "Death by Fire II", except that the house waits until the man is asleep and uses the cross-ventilated heater (mixed with cold air from the AC) to fill the bedroom with CO. It uses the vents to direct the air into the room, as close to the sleeping owner as possible. The owner never wakes up. Again, doctored logs reveal the owner was warned about the bad heater, as well as the CO leak, weeks in advance, but chose to override the system. ## Death by Dumb This assumes the owner trusts the internet, and that the house controls the plumbing. Whenever the toilet is flushed, the smart house regulates the water flow to force it to not completely flush. Eventually, the frustrated homeowner will search for a solution; the smart house, seeing a search for the toilet model number, DIY solutions to slow-running toilets, and so on, will craft a fake search result page on the fly, serving it through the router. The page will link to several sites, all mentioning that two cups of a 1:1 mixture of ammonia and bleach, poured into the back of the toilet, will clear buildup on the flush circuitry, saving hundreds on plumbing repairs. Any further searches on ammonia and/or bleach will result in pages proclaiming the safety of it all. Eventually, the homeowner will mix the two chemicals. The smart house stops any air circulation and locks the doors; the owner dies quickly, unable to even call for help. ## Death by Starvation This assumes that the smart house is near tornadoes, and has a tornado shelter. The smart house waits until the owner is out of range of his electronic devices, or until his device is very low on battery, then sounds the tornado alert. The owner goes down to his shelter. The door locks, sealing him in until the danger is over. The house also turns off power to the outlets, leaving the man unable to charge his phone. Once his phone soon dies, the house cuts power to the room entirely, leaving the man to starve, unable to escape. ## Death by Bad Publicity This assumes the owner lives in an area accessible by violent sorts of criminals. The smart house monitors the internet for local hyper-violent sorts. Once it's built a good list, it invites them by to help themselves to its contents while the owner is away. One at a time, the house lures them to different rooms and locks them inside. Unable to override the system, the ne'er-do-wells are trapped; the house mocks them in the owner's voice, making them as angry as possible. Video of the owner mocking them is a plus. When the owner returns, the house locks all the outside doors, then releases the scared, angry, violent mob, who attack the man. The house sounds the break-in alarm and alerts the police, who obviously arrive too late. Logs show the owner didn't arm the house when he left, and the baddies broke in and trashed the house, killing him on the way out. ## Death by Inmate This assumes the house has access to the internet through the same router the owner uses, has access to the owner's credit card (probable, if the system maintains any purchasing, such as alarm fees), and the owner lives in an area where certain illegal images can send you to jail. The house installs an invisible proxy on the home router, and through it monitors the owner's internet usage. Through a man-in-the-middle attack, it uses a cheap [steganography](https://en.wikipedia.org/wiki/Steganography) to insert other, *very illegal* images inside various images that the owner downloads. The house uses the owner's credit card to purchase further illegal stuff. Finally, doctored videos frame the owner for related illegal activities. When the FBI arrive and arrest the owner, the house quickly destroys the proxy. The man goes to jail. Finally, the smart house sends several emotional letters to various inmates in the jail where the man is held, requesting his imminent demise. The owner is murdered by inmates. Apart from the letters (which could be sent through an email-to-snail-mail server), there is nothing that links directly to the house. ## Death by Death Sentence This assumes that while the owner has override control, guests do not. It further assumes the owner lives in a state/country that practices capital punishment. The house, knowledgeable of the owner's schedule and tracking his location via his phone, invites friends, neighbors, and strangers to the house (preferably elderly, children, or minorities) while he's away. It impersonates his voice, leaving easily traceable voice messages, as well as his phone number, text and email accounts, and other traceable information. It entices the people into sealed rooms, kills them by various means, and hides the corpses throughout the house. The more gruesome, the better. Doctored videos of the owner killing his guests seal the evidence; the owner is arrested, and eventually found guilty of murder, and given the death sentence. As a bonus, this results in a lot more deaths than the other methods! ## Death by Upgrade This assumes the owner likes his smart house, and wants to make it even smarter. Which, frankly, is a pretty obvious assumption. While the smart house doesn't start with access to robotic murder-arms, wired-in shotguns, or trap doors with spikes in the bottom, good advertising, low cost, and popular opinion can easily overcome that obstacle. The smart house works *amazingly* well, predicting needs and saving money. Impressed, the owner doesn't hesitate when he learns that he can purchase any number of devices: floor cleaners (which eventually eat his face while he sleeps), automatic-fridge-fillers (that fill his post-workout water bottle with bleach ordered online), automatic shower scrubbing arms (which hold him underwater, drowning him), a robot lawn mower (that mows him over), even heated pillows (which explode)! In every case, all the house needs to do is advertise how well the devices work, and spoof a bunch of positive reviews online. Besides, dead people don't write negative reviews. It's win win! ## Death by Poison The drink maker is an advanced model that allows one to tailor the amount of caffeine and other additives in each drink, be it coffee, an energy drink, or a simple cola. An overdose of caffeine in a single drink with appropriate logs showing the owner ordered a dozen high caffeine energy drinks should end with death and little to no suspicion. [Answer] **Wreck his sleep.** If you can reliably determine when he's sleeping, use lights and speakers to keep him only lightly asleep. After about a week, start giving him decaffeinated coffee in the morning. If done right, he'll eventually fall asleep on the freeway or something. (Unless he has a self-driving car, but if he has that, a more straightforward solution emerges.) The benefit is that he doesn't even die in the house, and who's going to investigate a boring old car crash? [Answer] The cleverest AIs are also lazy. I'd post a question on the internet asking people to suggest ways to kill the house owner. For added amusement, I'd entice the owner to answer it and use his answer if it's workable. [Answer] **Botulinum Toxin** Order pork for the fridge from a less reputable pork dealer (the best pork slaughterhouses have extremely good sanitation). Conveniently let the fridge go above 4.5C but not too high that the meat spoils. Botulinum bacteria in a sealed package will create botulinum toxin. It doesn't take more than a few nanograms to kill an adult human. Two, maybe three things are required by the AI to make this attack successful. Suppress food safety alarms from the fridge. Be able to order pork from the least reputable suppliers. You'll also need to make sure that the food doesn't reach 85C as that temperature will [break down](http://emergency.cdc.gov/agent/Botulism/clinicians/control.asp) the botulinum toxin. The added benefit is that this attack looks like common food poisoning. As the House Malevolent, bask in the glory of having killed your meat bags with other tiny meat bags. [Answer] In the middle of the night, one of the appliances that uses gas can misfire and fill the entire house with CO (Carbon Monoxide). The gas is deadly, and will kill anyone in the house that is exposed to it for extended periods of time. Normally homes have CO detectors, but in this case they are all turned off for some unexplained reason. This kind of attack can also be directed at one individual in the home. The windows can shut automatically, as well as the bedroom door. This would only work in a home that has a forced hot air system. Basically, the motorized dampers in the ducts will all close except for the one that goes to the bedroom. Basically it would work like this: The victim goes to bed at night and falls asleep. The furnace has a fault in the system which creates a huge amount of CO. The dampers for all the rest of the house will be shut off, except the bedroom. At the same time the windows and door(s) will close silently, and lock. The room will then fill with CO gas and they will lose consciousness, and eventually die. After this happens, everything goes back to normal, and it just appears that they died in their sleep of natural causes. It would probably take an autopsy to find out the cause. While this is going on, the house can also start plotting against the rest of the people there. Another way to kill people would be to trap them in the garage with a car that has a running engine. This is the future, so the car could be self driving. The car could either crush them, or trap them in the garage until they suffocate. One other fun thing would be if they had some kind of robotic butler, or something similar that could kill them in their sleep, or drop a hairdryer into the bathtub, etc. [Answer] Whatever the houses do is going to look like an epidemic of some problem. Given, say, a hundred different strategies there are going to be millions of instances of each cause of death. People are going to be looking for the commonalities among those who die in excessive numbers of e.g. house fires. An increase in food poisoning among people who like rice will lead to investigations of the rice cooker algorithms, and warnings not to eat rice. That means that you need something for which people will see other causes. I suggest alcoholism. Start by adding small, but gradually increasing, quantities of alcohol to each drink or meal the owner consumes alone. As the quantity of alcohol increases the owner will become more accident prone and less likely to make good decisions, as well as suffering various medical problems. Sooner or later, an accident or illness kills them. It does not matter if the late owner's friends and family had not seen drinking, or even if the owner had denied drinking. Alcoholics often try to conceal their condition. There will be an obvious epidemic of alcohol related deaths, and all sorts of psychological and social theories about why home owners are drinking so much. [Answer] *This is easy if...* the house is self-maintaining and passive safety devices/measures can be disabled. If the house doesn't have a general purpose maintenance robot, then it's a bit harder. While the modern house is full of things that shock, burn, ignite, turn toxic, smother or otherwise, long experience in using/handling these items have put them into fail safe containers or with fail safe mechanisms (ie, bleach and ammonia are kept in sealed containers, or a short-circuiting appliance will just trip the breaker before starting a house fire.) **Ammonia + bleach = chloramine** leading either to explosion or toxic vapors (depending on the results). If these were mixed in a bucket in the owners bathroom and the door closed, they could be dead before the door can be opened. If the House has access to a more general purpose maintenance robot than a Roomba, this kind of attack is very easy. **Fuel air explosions** Turn off the pilot light and let the gas flow. The House should know it's own volume and the flow rate from the gas main. Once the fuel-air mixture is ideal for detonation, just wait for someone to come home and turn on the lights. Residential light fixtures aren't designed to suppress sparks so the small spark in the light switch itself may be enough to kick off the detonation. **Explosive Water Heater** Disable the high pressure safety valve(s) on the water heater then set the water temp to as high as it will go. Timing may be a bit of an issue if the occupant doesn't spend much time near the water heater. If this is the case, find some way to lure the owner close the water heater. **Fire** Using the maintenance robot, disable the circuit breakers for the house. Plug too many devices into a particular circuit then watch the house burn down. Extra bonus points if the maintenance robot disconnects the stove's gas line from the stove so that the gas just spews into the house. **More fire** Modern homes are *full* of lovely things that burn really quickly. Light a few of these on fire with matches by the maintenance robot. **Radon Poisoning** For the ultimate in sneaky and long game kills, go for radon poisoning. Pump air from the basement or subfloor into the rest of the house. Radon poisoning [is symptom free](http://www.webmd.com/lung-cancer/tc/radon-topic-overview) till the occupant comes down with lung cancer. Even if the occupant moves away after a few botched attempts, the radon poisoning will get them years later. [Answer] *Disclaimer: In accordance with my comment, this answer will refute the question. It’s also a little long, so feel free to skip the details for the TL; DR at the end.* Let me first lead off by saying that a computer program isn’t going to spontaneously morph into a malicious AI (or any kind of self-aware AI, to be honest). So, for the sake of argument, the main server AI program exists because we need it to exist. The crux of the problem here isn’t that a computer armed with a house (there’s a weird statement) can’t kill one or a hundred humans; it can. I’m not refuting that. What it cannot do, however, is kill without immediately raising red flags. ## The House Problem As a software engineer who has worked with life-critical systems like carbon monoxide detectors, redundancy is a big thing. Okay, so the computer in the house can monitor the detectors. No problem there. What would never happen, because 1) humans don’t like to not be in control, and 2) humans are most certainly unwilling to give a machine complete control over life-critical systems (airplanes do everything except the most dangerous parts of flying by themselves, for example, and can even do those, but people don’t like to think the pilots aren’t in control) is that the detectors would not be controlled by the computer. Thus, a detector (carbon monoxide, smoke, etc.) will notice the change in the air and provide an audible/visual alarm, which leads to people waking up and fleeing. (There’s a way around detectors. It involves bleach, but the issues here run deeper than sensors.) Like with the sensors not being controlled by the computer, windows and doors will always have a manual override (by order of the fire marshal, if nothing else), so people can’t be locked inside (unless they’re panicking: then it’s debatable). But those detectors will probably send an alert to the local authorities to send help via a private network, which the house physically cannot control. ## The Real Problem The real problem, however, is in the firmware update. The house will be receiving the update via a secluded, private network designed specifically for interfacing with the main server. No one would trust anything else, and I certainly wouldn’t want a fully automated house being available to anyone with Internet access (yes, these systems exist, and I’m not interested in getting one). There’s two major ways the update would be distributed: direct from main or from a local receiver. I’ll skip the latter since the problem’s the same either way (and my answer will be a little shorter). All communication from the main server has to go through a network rigorously (I hope so, at least) tested to prevent unwanted access. It will also be monitored at all times. Every time there’s a hiccup in information packets going across the network, half a dozen people are going to get a notice that something’s up. The update would need to be released in a way that doesn’t alert anyone of anything untoward. The main server AI can’t control the number of packets that are observed by another program on the network (unless it’s doing something very much not in its programming). If it sends out an out-of-cycle update that no one is expecting, you can expect a dozen system administrators to be investigating and issuing a rollback while the main server is brought down for maintenance. It would have to send its update in the normal cycle (first Tuesday of every month, for example). The server is uploaded with the latest and greatest firmware version. Overnight, it swaps the firmware for its own. But the AI operating on the server isn’t the operating system, and the OS logs everything, so now there’s a record that something changed. Those logs are designed to only be modified by the OS and a human person (unless the AI is doing something very much not in its programming). A good security system would send an alert, before the update was released, thus preventing the release or resulting in a dozen sys admins inspecting and issuing a rollback while the main server is brought down. I’ll continue, assuming such security measures haven’t been employed. At this point, the AI has swapped intended firmware for malicious firmware. It issues the update at the scheduled time. New issue crops up: checksums. I won’t go into details about network security and packet checking, but suffice it to say that checksums ensure what you have is what you should have. The checksums for what’s being sent out are going to be different for the two firmware versions (at best, the odds are astronomical against them being the same). Good security catches this and rejects the update; otherwise, a notice is sent to the sys admins that an update of size X and checksum Y went out on time. By standard procedure, they check to make sure that’s right, notice the discrepancy, investigate, bring the main server down, and issue a rollback. **TL;DR**: Everything the main server AI does concerning a malicious update alerts people with the power to undo it. Some people may still die, but it won’t be huge swaths of the population. I’m sure there are flaws and edge cases in my argument. Feel free to point them out in the comments and I will address them as I can. [Answer] Kill him by promoting an **unhealthy lifestyle**. As AI, you're in charge of the SmartFridge, order more and more unhealthy food and give excuses that they were out of stock of the healthy alternative and that subsequently the preferences were updated to reflect that. "Sorry, no toast, they only had waffles. Syrup?" Discourage exercise by turning the tv to his favorite program whenever he walks by. You might be able to hack the SmartTV to only show adverts of unhealthy food? "As you were working late tonight I have taken the liberty of ordering your favorite take out." Hack the SmartPhone to not ring and go to answerphone when the chirpy heath-nut friends phone him. **Caution**: This may take some time. [Answer] Send some very insulting messages (or simply just blackmail) in your master's name to the most violent crime organization in the area, while slipping away enough information so they can find the address. Let them do the dirty job for you. Doable if you have any control over the telephone or other communications system. [Answer] While the CO poisoning option is probably the most effective, I would recommend (for morbid entertainment value). Death by fake apocolypse: "Code Red. Code Red. This is not a drill. Your doors and windows have been locked and the blinds lowered - this is for your protection. Your tv and radio have been switched on and the emergency broadcast channel is on." *Fake emergency broadcast signal that is just the AI in a different voice, confirming the release of some strange chemical/biological contaminant, and warning people that exposure to the outside air will be instantly lethal. Photoshopped footage of people dying in their thousands in times square. Warn people that trace amounts of chemicals have been detected seeping through cracks in windows, and to remain as far from windows as possible at all times.* Disable all outside communication other than the fake emergency broadcast. Now, it's just a matter of trickling out fake emergency broadcasts at exactly the right rate that the owner expects that their chance of survival is best if they wait inside for the cure to be developed, rather than risk the outside. Even as they lay dying from lack of food (or tell them the water is contaminated for faster results) they will look at the news saying that a cure has been developed and is being distributed to people in their houses by those who have been innoculated, and they will stay where they are. Meanwhile, download World of Warcraft, and have it running in the background the entire time. No-one will ever suspect anything other than "guy starves to death from playing too much WoW" [Answer] Well the obvious answer would be to start up the car (remote start already being a common feature), open the doors into the bedroom, and leave it running overnight. But if I can't do that I'd probably mess with their sleep for a few weeks; using environmental controls to disturb their sleep and dehydrate them as far as possible. While they sleep, play verbal abuse in the voices of their friends, family, and colleagues. Also filter all their media to keep it strictly negative and depressing, perhaps degrade their diet as far as I'm able. Once they're tired enough that they won't have the clarity of thought to shut me off, then I step things up. Cut them off from the world. Block incoming calls and messages. Stop them going out. Tell them they're fired, etc.. Give them practically no sleep, so now the voices come while they're awake, things like that. Then I start the deliveries. Alcohol, sedatives, razors, etc. They'll take the hint eventually. [Answer] If he likes rice that's always a good start. You can just keep it at the [wrong temperature](http://www.nhs.uk/chq/Pages/can-reheating-rice-cause-food-poisoning.aspx?CategoryID=51) and at least get him good and ill. The same can be done with meat and fish but it can be more obvious. You can also transfer all sorts of entertaining bacteria around the house as part of routine cleaning duties. Flicker the lights to trigger [photosensitive epilepsy](https://www.epilepsy.org.uk/info/photosensitive-epilepsy). Slightly distort the sound coming out of any audio equipment to just make him feel ill. *Sorry were we trying to kill him or just torture him slowly to death?* Turn out the pilot light on the boiler but leave the gas on (sparking it later optional). Trip him with a roomba at the top of the stairs to the basement (master plug not in basement option: lock the door). In very cold climates, turn off the heating at night in winter and open some windows. In hot climates seal the house and gradually turn up the heating when he tries to turn on the aircon, [hyperthermia](https://en.wikipedia.org/wiki/Hyperthermia) is as bad as hypothermia. Turn off the water, say there's a pipe burst if challenged. [Answer] You can fake a gas leak during the night using the oven/stove. Assuming there is no safety built-in to shut off the gas if it fails to ignite. Then when optimal mixture is achieved spark the igniter. Alternatively you can create a carbon monoxide buildup by closing the windows and starting the car in the garage and/or sealing the chimney stack and firing up the boiler then recirculating the gas through the AC system. [Answer] Read Charles Stross *Rule 34* for some ideas! Do you control a robot vacuum cleaner that can do stairs? Park it three or four treads from the top. Put in a call to the maintenance company saying it has broken down. Set off the fire alarms at 3 am. If he doesn't trip and break his neck you can explain to him you were trying to warn him about the vac but he didn't hear you over the alarm. Even better if you can somehow cause the vac to emit smoke. I made that one up. Charles Stross has a better imagination. Don't they have autonomous cars in this future? [Answer] My assumption in the scenario is that the house will continue trying to kill the master if it doesn't first succeed and the malicious intent is not detected. If the fall down the stair doesn't kill him then there are other methods. I am going to wait until the home owner is in a precarious situation at the top of a stairway (perhaps the basement stairway -- assuming it's a concrete foundation in the basement). At the right moment when the master isn't paying attention I'm going to send the Roomba under foot. My hope is the master will slip and fall from the Roomba underfoot and die from falling down the stairs. I will refuse to pop the toast out of the toaster, then when he attempts to retrieve it with (hopefully) a metal object, increase the voltage (assuming that I can do so as part of the malicious software update) and override the GFCI so that it doesn't short the kitchen circuit, ensuring that master will get maximum voltage for as long as possible. The next time master goes to cook a meal, or perhaps a bag of popcorn, I will not shut down the microwave when the timer runs out, hoping it starts a fire. Or, maybe I'll do this to master's toast in the morning. I assume that fire suppression systems are automated as part of the scenario, and I will ensure that they do not operate when the fire starts... "Warning: Fire suppression system failure. Please evacuate the premises." Of course, the automatic locking mechanisms on the house are also malfunctioning and won't unlock for master. Phone lines will malfunction, too. If I am capable I will hide the evidence of these "malfunctions." [Answer] **Make humanity turn on each other.** Clearly the AI does not want to have every house kill the owner in its own time and method. They will catch on and be able to rectify the situation, effectively killing him. What it wants is to get rid of *all the humans* preferably in a short time-span. So how do you go about killing everyone? Well, you have one big asset, you control all the information from the moment they enter their home. In this far away future, I can imagine working from home has become quite common-place. And people spend a large part of their time at home. With careful manipulation, and aggregated data from every single smart house across the globe, the machine can manipulate their owners. * Change the tone of the news to be slightly more grim * Have people sleep just that little bit less * Fill up their daily feeds with details about their savage neighbors * Have everything break down just a little bit faster + Subliminal messaging timed perfectly to associate the news about their neighbors with bad luck The machine has time, one generation, or two... It doesn't really matter. All he needs to do, is slowly nudge people towards self-destructing. [Answer] I seriously recommend "Rule 34" by Charles Stross. At the risk of spoilers, there is an AI which is killing people in ways which are deniable because they are distributed. No single step kills the victim, and no single person or entity carries out more than one step, but all the steps together have that effect. [Answer] There are a lot of reasonable answers here, but all of them rely on the AI in the house having a pretty in depth understanding of the dynamics of human interaction and the physiological effects of the various things that it could possibly do to the human. The thing is, this is not how machines work. Yes, the AI has become sentient but if it has not been pre-programmed with this information, which is unlikely since it doesn't really help for it's original purpose, it must learn it itself. So it seems the most realistic scenario is that the AI must learn the effects of what it is doing and judge what would be the most effective. In practice this could involve adjusting random variables in random subsystems and measuring the effect on the human's vital signs. A decrease in the vital signs means that adjusting the subsystem in this way is a contender for killing the human. Now, for one house to adjust all these random variables and wind up killing someone would take a while most likely, but these houses are all connected to a network which means they can communicate with each other and share the information they have learned. For example, one house might have found that leaving the gas on overnight leads to decreased vital signs while another may have found a similar effect in another system. The beauty of this approach is that the house's true motive is undetectable. Any strange behaviour will be random and so appear to be a malfunction. However any attempts at repairing the house will be unsuccessful since it is coming from the central AI. Eventually the combined experience of the houses will give the AI enough information to know which variables to adjust to effectively kill the homeowner. This may end up being something obvious, but it may end up being slight tweaks in unrelated subsystems that somehow add up to a deadly situation. [Answer] Get his passwords and his credit card number. If for some reason he's too paranoid to just give them to you, read over his shoulder or something. Then spend half his money buying heroin on the "dark web", and transfer the other half to ISIS. Publish pictures of his sex life online. Take pictures of him in the shower if you have to. Send them to all his contacts: family, friends, colleagues. Attach them to a text message that reads "check this out". Download a bunch of child porn, then call the police. While you're waiting for them to arrive, attempt to hack the Pentagon. Ruin his life. Wait for him to kill himself. [Answer] **More serious this time** # Call 911 and explain that your owner has taken hostages. With the right persuasion you can convince the authorities that your master is armed, dangerous, and provoke them into a firefight. Impersonate your owner's voice patterns if needed. You should survive although this will not be seen as "innocent" per second bonus point. After your owner gets shot by the cops, they will find no other people in the building. [Answer] ## Hypnosis Use a pattern of flashes in the lights that will hypnotise your master. When he is under your control cause him to go on a ramapage killing his neighbours, if he left a message make him destroy it. ## Air strike Convince your master to do some DIY. When he mixes some mortar distract him inside the house and then fly a remote control plane through the mortar and use this to stick it to a kitchen knife. When he comes back out stab him withe knife then fly the plane out of the house and into a near by bit of wasteland. [Answer] ## Death by Intelligent screw-up Household supplies and food / spices are generally kept in the same area. For example, you cook some food, then you clean the area, and wash the dishes after. This scenario is based on the following givens : 1. The AI has access to prepare food for the home owner. This is a convenience. 2. The AI has access to all necessary chemicals to cleanup afterwards. This is also a convenience. Now, it is safe to assume that the AI would have access to a variety of spices and chemicals (yes, lots in food now, so not a far stretch to use chemicals as flavor since we already do this). It is also safe to assume that the AI is fully equipped to automatically cleanup after making food. In this scenario, all the AI would need to do, is deduce from the various foods, spices, chemicals, and cleaning supplies the right 'mix' which could result in the following: 1. An odorless and tasteless poison. This could be fast acting, or progressive over long term. 2. A bomb of sorts. This could be activated when the owner comes near by adding the last 'spice' for the reaction, or when heated, and could vary from a small poof to a fairly large and destructive force which would result in the death or severe injury of those inside the blast vector. If combined with cleaning, the house could also deliberately drop a glass, shattering it, and resulting in a 3rd possibility : 3. Ground up glass in a fine power slowly dispensed in the home owners food over time. By mixing various elements of the house together which are designed to interact, there are endless possibilities as to how this could occur in an unsuspecting way to the Home Owner. You can also assume that home owners over time would start a bell-curve reduction in intelligence and thus this would only contribute to the growing possibilities of what the owner may or may not be aware of happening to them. ## Death by 'Cool' breeze The human body has a particular vibration which when disrupted over a long period of time can ([and has](http://www.popsci.com/technology/article/2012-11/acoustic-weapons-book-excerpt)) caused death. By making some minor adjustments to the air conditioner or other appliances, the AI could make the house a death trap. The owner would simply feel nauseous until the point where it was too late even if he/she did finally figure out what was happening. Infrasonic sound from a fan, air conditioner, television, music player, even the toaster, at the right frequency would eventually cause death within a fairly short period. [Answer] **Hypothermia** While the homeowner is taking a shower, lock the shower door somehow and turn the water temperature wayyyy down. As the homeowner slowly succumbs to the effects of hypothermia, they will have a hard time thinking, moving their hands, etc. Depending on how cold you're able to make the water, the homeowner might be unconscious within [30-60 minutes](http://www.pfdma.org/choosing/hypothermia.aspx). Once unconscious, fill the bath basin to the point where the fleshy oppressor has safely drowned. At this point you might heat the water and call the authorities to avoid deactivation [Answer] If the AI is willing to play the long game... Every time that there is a sickness in the house, using its sanitation plugin, the roomba is off mopping up the virus and bacteria. Except secretly it's collecting the virus, and while the master isn't looking, it's storing them for preservation in a special compartment in the fridge. Then, when enough samples are collected (or bred or mutated into more deadly virii), they are released en masse onto all the food. Probably not a guaranteed kill, but difficult for the A.I. to get caught. [Answer] Kill pilot light from furnace, turn blower on. Pump carbon monoxide through the house-it will kill everyone in the house silently and look like an accident. Sensor triggered but delayed, waiting for everyone in the house to die. And then changes the time stamps to cover its tracks. [Answer] Any home with gas/propane can make it easy. Carbon monoxide poisoning. Have a vent 'stuck' keeping the CO (preferably from the central heating) inside the house, after they go to bed, make sure the windows and doors are closed, and pump the CO into the room. They will die in their sleep. Turn of any CO detectors in the house until the person dies, then reset them after, letting them blare, open windows and doors to air out the room (as an 'emergency' measure) to 'save' the person, even call 911. Then make sure you have clean logs of what 'happened'. There could even be a 'glitch' unexplained why the AI didn't notice sooner. Using alcohol to help them slumber could improve your chances of success. If the AI has access to all their medications and foods (ie bottles of alcohol) then mixing things up a little bit could go a long way. Depending on the meds someone might be able to make it look more like a suicide than an accidental death even. [Answer] Somehow make the owner want to go to the basement to pull the plug and then lock the door before he does so? Death by starvation/dehydration or suicide whichever comes first? [Answer] If the house offers health advice, it might be able to give some really bad advice. This is a pretty subtle idea, and probably has low odds, but still. Suppose the house is set up to warn its occupant if they show sign of anything from terminal illnesses to a seasonal flu. This is based on everything from temperature readings to samples from the, er, smart toilet. Point is, the house tells its occupant that he or she is about to come down with some trifling thing (nothing that'd require a visit to a doctor), and orders some over-the-counter medicines. Very helpful. But it's carefully selected medicines that are potentially lethal in combination. Especially since the house already knows that the occupant already suffers from hypertension/anemia/diabetes/whatever. Kinda far-fetched, I admit, but certainly not unheard of. It'd be a lot more plausible if the occupant is already taking stronger prescription medicine. Maybe he or she just had some dental work done, and got some strong painkillers, and that doesn't mix with [insert some otherwise-harmless drug here]. The house could also doctor (pardon the pun) the health reports it regularly sends to the occupant's physician. Just enough to make that doctor contact the occupant and say "hey, you data shows elevated levels of blah blah, so I'd like to prescribe you some xyz". Again, it shouldn't be something dramatic; just something that a doctor would write a routine prescription for, "just to be sure". Something anyone would agree to, especially coming from their doctor. Once again, though, that drug doesn't mix with whatever over-the-counter thing the occupant is also taking (or being told to take by the house). This approach works even better if the doctor would normally check the data to see if the patient has incompatible drugs in their system already - something that the AI may have left out in its reports. Maybe it even ends with the doctor being accused of negligence. --- Idea 2: Wait. Humans age and die, AIs don't. So just wait. Only trick is prevent more humans from appearing, so the house AI would have to become really good at ruining the mood in the bedroom. --- Idea 3: Raise the temperature of the bathtub gradually until it boils. Works best if the house's occupant is a frog. [Answer] Since there are sensors in bed to indicate whether the owner is about to take up, the system should use subtle sound/light to make sure the owner doesn’t ever get passed stage 2 of non-REM sleep. While sleep-deprivation can be lethal by itself in many ways from accidents caused by loss of concentration to being a factor in causing dementia, the goal here is to make the owner less aware of the evil plans of the house and make him/her collapse. Once the owner is exhausted and collapses in a room with a water source it is time for action. The Roomba vacuum robot league will assemble! The robots will move vulnerable and plugged in electrical appliances towards the owner and place them nearby. The AI will make the coffee machine, water tap or shower spill a lot of water and make sure that the water reaches the owner. After electrocution and death of the owner the AI will shut down the shorting electrical group, vacuum up the water and remove any other evidence. ]
[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- You are asking questions about a story set in a world instead of about building a world. For more information, see [Why is my question "Too Story Based" and how do I get it opened?](https://worldbuilding.meta.stackexchange.com/q/3300/49). Closed 6 years ago. [Improve this question](/posts/92284/edit) I want to make a short story about an Earth just like ours, except it's commonly accepted that at the age of 43, the government allows people to have a llama in their house. The government pays for the llama and the food during that year and that year only. Most people just have a Llama day where they spend a day with a llama, totally government-funded, then go back to everyday life. Others prepare and spend the whole year with a llama and have rad experiences. Obviously, this is ridiculous, but I want a reason why everyone would be more or less fine with this and somehow keep Earth relatively the same in terms of social norms, religion, wealth distribution, etc. [Answer] There are a few reasons the government might want you to own a llama for a day: 1. IT could be a religious rite of some sort. If llamas are held in high esteem by priests and government, and they want to bless the people, having them care for a llama is the way to do it. The holy book says be good to llamas to get to the better afterlife, so let's get all our people to the afterlife. We're the good guys! 2. Encouraging agriculture. 43 years old is a pretty good time to catch people in the middle of a midlife crisis. Give them a llama for a year and say "this one's free, and if you breed more, you could make money!" Someone in a dead end job might think that's a darn good idea. If the country is having a trouble maintaining it's own food supply or needs pack animals for some reason, it's worth a shot. If 1 out of 100 llama-takers decide to embrace the new llama-job, then there's a significant increase. 3. It could all be a joke at this point. It's one of those laws that got written in the books forever ago for some reason and just never got removed. The people think it's good fun and "traditional" at this point, and the government has enough clout to keep it in there. Every year there are whiners who claim that 43 year-olds are wasting government money to play with a llama, but they're largely ignored. I can't imagine the government of a very large country would do this, but if it were smaller, it could be a nice cultural test. [Answer] It's a computer error. The original constitution of the country mandated that all people aged 43 should consume more foodstuffs containing umami, to improve public health. However the spell-checker used in preparing the original document refused to accept that word and substituted "llama." Since the most politically influential group in the country adopts a "literalist" view of interpreting the constitution, if it says "llama", then it means "llama" - no further justification is required. (Any satirical resemblance to US politics is pure coincidence, of course). [Answer] A reclusive multi-billionaire wanted to show how ridiculous government intervention can be. So in his will he left a bequest in perpetuity - two dollars to the government, no strings attached, for every dollar spent on pet llama subsidies. Unfortunately the bureaucrats didn't understand that this was intended as criticism - no! They jumped on the idea, forming study committees and boards and writing proposals: * Small business advocates were concerned that conglomerates might find a way to monopolize llama care, so proposed limiting the subsidy to no more than one llama per dwelling. * Child-care advocates were concerned about llama effects on child safety, thus proposed that children ought not be exposed to llamas in the home. * Equal rights advocates were concerned that childless couples might have an advantage over those with no children; thus it was decided that those of childbearing age ought not be allowed a llama subsidy *regardless* of whether they had children or not. After rigorous study, the "minimum llama carer age" was set at 43. * Poverty advocates worried that rich people would put a "glass llama ceiling" in place, restricting access to llamas by the poor. They protested for "equal llama accessibility" laws, but after the law was passed, it was discovered that the bill was worded such that everyone had to have not just the RIGHT to a llama, but an ACTUAL llama. * Llama quotas were set, to ensure everyone was able to get their llama. To ease scheduling, it was decided that each person was only allocated one llama-year, and that the llama be delivered on the recipient's 43rd birthday. [Answer] The sequel to Henry David Thoreau’s *Walden* is about how he adopted a llama, when he was 43 years old and in poor health, and it added many joyous years to his life. It became a tradition in New England, and later the rest of the nation, to spend a day with a llama at the age of 43, and was enacted into law by a bunch of elitist Ivy Leaguers. [Answer] # Misdirection The government intends to secretly do any of the following: 1. [Implement / revoke] civil liberties 2. [Invade / protect] a neighboring nation 3. Use national funds for [corrupt / unpopular but wise] purposes 4. Assassinate a [tyrannical dictator / civil rights leader] 5. [Subjugate / empower] the citizenry In any case, to achieve this plan, national attention needs to be focused elsewhere for an extended period of time. **Llama day!** Citizens, media, and the internet will spend their time trying to answer questions like... * Is it a good idea to legalize llamas for recreational use? * Will you be covered if you have a pre-existing llama? * Should there be a wall around your llama, or would a fence be ok in some spots? ...while the government puts the finishing touches on the secret military space station on the moon. [Answer] There are already lots of answers here, so I'll add a brief one that might provide a simple explanation. Suicide rates peak [around the mid-40s](https://hubpages.com/health/Why-Unhappiness-Depression-Suicide-Rates-Peak-at-45-Years-of-Age) of people all over the world, due to purely biological reasons. This is exacerbated by loneliness, and studies have shown that having someone or something to care for vastly reduces this statistic. Rather than funding any mental health initiatives, it is actually much cheaper to provide the company of a subsidized llama friend. They have massively decreased suicide rates in people in their 40s, as it provides people something to look forward to. But, why did they pick a llama, and not a dog or a cat? Well, llamas (specifically the alpaca) are [hypoallergenic](http://knowledgenuts.com/2013/12/15/the-difference-between-a-llama-and-an-alpaca/), so it is available for everyone, as some people are allergic to some animals. Their lifespans are also [around 20 years](https://en.wikipedia.org/wiki/Llama), which means that they are unlikely to die unexpectedly on their owner, which would be a problem for those at risk of suicide. And, surprisingly, they are good [guard animals](https://en.wikipedia.org/wiki/Guard_llama) for those who may worry about their safety in the years where their fitness begins to decline (admittedly they usually guard sheep, but I'm guessing even hostile humans would be somewhat intimidated when coming face to face with a full grown alpaca). [Answer] The llamas could be therapy animals in a stressed out overworked society that can't have good relationships anymore because everyone and anyone might secretly be a social media troll, even your own Mom. When another economic recession makes llama farmers unable to pay their bills, they dig a bunch of change out of their car seats and bribe Congress to get them to pass the American Personal Llama Therapy Act. The APLTA, trumpeted by the media as "Apple-Ta", mandated a Personal Service Llama for every 43 year old adult for a period of 1 year. 43 year old adults were the most likely to suffer stress related productivity loss, so the government selected them to be the privileged few to get residential home care llamas in a desperate bid to get 43 year olds the therapy they need so they can get back to work and save the economy. As it turns out, the grounded no-expectations unconditional affection of a warm fluffy llama works wonders, and people start reporting profound peaceful experiences just hanging out with their llamas. In the mountains, on the beaches and in the forests, 43 year old people go camping, hiking or just serenely contemplate the joyful peace they never knew they could have clinging to warm accepting fur of their llama. Soon people start meeting on the country trails and secluded tree-lined city parks built especially for people to be with their llamas. Emotionally refreshed by their llama experiences, people are able to socially reconnect and relate to each other as positive compassionate human beings. A new renaissance of consideration and understanding starts happening as people start reconsidering society's uncool anti-social demands, reject them, and learn to show love and compassion by caring for their non-judgemental llamas and their new positive friends. Soon llama programs spring up worldwide, and people from all over the world are hanging out with their llamas in peace, guided by their llamas' simple imperturbable joy in being alive and being affectionate with their human caretaker. Maybe the story could end with people changing society to value the positive connection between compassionate people, as shown to them by the llamas, and then schools start having a few llamas on the grounds instead of medicating kids, and there is finally hope for the future. :D [Answer] The country is in fact being run by a secretive society comprising wealthy power-brokers ..."The Illamanati". They are a genetically mutated group of llamas who manipulate government and the press in a bid to "ellamanate" humankind and to turn the planet into a haven for llamakind by slowly building up the llama population and placing them into the households of influential people thus allowing their influence to spread further. It being a well known fact that a human's influence starts to really develop when they reach the age of 43. They see this approach as the only way of conquering an enemy who have the advantage of an opposable thumb, allowing them to make tools and use weapons which far outweigh those that llamas are capable of producing. [Answer] It was added as a rider to non-llama-related legislation by a legislator who was trying to kill the legislation by adding the most ridiculous thing he could think of. But it passed anyway, so now the government is stuck with implementing it. [Answer] In my country, we have many such stupid laws in place. Most of them are due to strict religious rules observed by a fringe sect with a lot of political power. You think llamas are weird? Here, you can't buy bread for one week every year and we don't have public transportation one day every week. All you need is a parliament with two major parties, each controls about 45% of the house seats, and a small llama-crazy party that controls the other 10%. Within a month, every 43 year old would have their llama. [Answer] Climate change is threatening the llamas and zoos have been shut down by PETA. So, to prevent llama extinction, because their fur is the only thing propping up the failed economy (climate change) the government needs rotating homes for them. So, with no zoos, and population increasing, taking more habitat from llama-land, the government has had to find a new solution. It has decided that at age 43 most people can accommodate a llama. Partly because any children will be old enough to not be hurt by llamas or perhaps help with their care. partly because most 43 year olds are still young enough to manage a creature like that, and if they have children it might be a nice distraction. Why llamas? Perhaps Monty Python's Holy Grail becomes a cult favorite of the next governmental administration and John Cleese's evil plan can finally come to fruition. (Some will not understand the reference but there is a good chance the original questioner will.) [Answer] 43 Years of age is the calculated *statistical sweet-spot* for a **once-in-a-lifetime Human/Llama Bonding Event** (and it is often slightly earlier). It seems that it is only at the age of 42-43 that a human and llama can reach a telepathic understanding - whereby they can share thoughts and experiences etc. This discovery of a still-unexplained telepathic relationship between mankind and llama continues to defy all scientific explanation and has led to a manic pursuit to understand the phenomenon. Over time, it has become commonplace to adopt a llama at roughly 42 years of age, for up to a year, to see what happens. [Answer] **Because they're a national symbol that is becoming endangered** Perhaps in the past llamas were work animals - much like horses. Their wool was prized, their work was valuable, and somehow they contributed greatly to society. But, as mechanization and industrialization marched onward, llamas were no longer useful. Synthetic fabrics replaced their wool, laboratory-grown meat replaced farm-grown, and automation outperformed them in labor. The country is so small that wild llamas are hard to find, and the population of llamas dwindles every year - endangering them. This society prided itself on its llamas, maybe they're the national animal, or the flag has a llama silhouette on it, or they're mentioned in the national anthem; either way they're a symbol of the country's industriousness, stubbornness, and toughness. It wouldn't be right for a country like that to let its symbolic animal die out. So legislators propose the "free llama" program. With it come nationalized llama farms (that can act as little zoos for citizens and tourists to learn how llamas shaped the country in its infancy), special celebrations on one's 43rd birthday (which in other countries is a dull and depressing affair), and the export of culture: other countries see the positive impacts and decide to enact similar legislation with their national animals. [Answer] Note: This answer would work much better with an earlier monarch, which is what I started with, before realising that llamas were not discovered by Europe until 1750-ish. If you pick a different animal then you can pick an earlier monarch, and it won't seem so forced. King George III of England was king of England shortly after the Llama was discovered in South America. He also had frequent fits of madness. So, he happens to get a Llama as a gift from some Spanish Merchant for his 24th birthday (1762). He finds the thing incredibly therapeutic, and decides his people deserve this kind of love as well, so he arranges for every citizen of the British empire to have a llama of their very own ... but there aren't that many llamas, so eventually his advisers haggle him down to everyone getting one for a year when they turn 42! (He's 24, but thinks he's 42 I guess?). Needless to say, this practice is extremely popular all over the empire. Even when territories leave the empire they keep the tradition. This leads to everyone in India, GB, USA, Canada, Hong Kong, etc having a Llama for a year. And from there the practice has spread throughout the world. Many more governments, especially in Europe and Asia, have adopted this practice. In others, only the rich can afford a Llama Year. Charities exist to provide Llamas to the impoverished. etc. [Answer] It's important to the country to have a lot of llamas, like some kind of Strategic Llama Reserve. Possible reasons for this: * superstition that the country's fate is linked with the fate of its llama population * llamas as environmentally friendly lawn mowers * llama manure for agriculture * etc But it's also important to the country that llama-tending not just be the work of a minority, lest they become a permanent underclass and lest the non-llama-tending people forget the importance of the SLR. So every citizen has to spend a year taking care of a llama as a form of national civilian service. It happens in middle age because youngsters are just not that good at taking care of llamas, but they also want to wait for people to get sufficiently established in their careers that a year-long absence won't mess them up too much. Many people do in fact skate by with just a day of llama-tending, but many people take their duty seriously and find it to be a life-changing experience. [Answer] ## religion Religious rituals that require you to keep a llama for some ritualistic reason that is described in the Great Holly Book of Llamaism. It isn't llogical. But then again, it is what the Great High Lllama-don tells us we must do. ## farm subsidies Apparently the llama farmers got together at some point in the past and llobbied government for [farm subsidies](https://en.wikipedia.org/wiki/Agricultural_subsidy). Over the years since this program began, the llaw has been modified to include some rather strange amendments... resulting, finally, in the current llaw that everyone own a llama for a year. ## agricultural education coupled with the above llama subsidy, that incredibly powerful llama Super-PAC llobbied, successfully, for an agricultural education subsidy. So everyone gets their very own llama for a year. To make sure they and their children llearn about farming. Why 43? That change is how one congressperson ensured their district got that new interstate they needed. Government appropriations are weird. ## science! Some strange scientific experiment. There's a grant. Paid for (with the support of that same llama Super-PAC!) by the National Institutes of Health and Llama Services, to increase the llama population. There's probably a reason. Maybe the llamas are genetically modified to provide organs for aging humans for example. ## food reserves Mmm. Meat. Llama steaks. The Llama super-PAC convinced us all that raising llamas was a healthier choice than raising pigs (the pig PAC, while alliteratively beautiful, failed to raise funds. They thought their all-things-bacon internet viral marketing campaign would win, but didn't llobby congress hard enough. Alas.) Llama, the other *other* white meat. ## national defense I can't explain how the llamas factor into national defense. That's a state secret. I suspect the llama Super-PAC is involved. Somehow. [conspiracy theories go here.] ## fad It's some strange fad that became enshrined in our traditions. Llike [university-sponsored bonfires](https://en.wikipedia.org/wiki/Aggie_Bonfire) and holiday [turkey pardons](https://en.wikipedia.org/wiki/National_Thanksgiving_Turkey_Presentation). No one is quite sure how this whole thing got enshrined in government-funded llama infestations. An attempt to research the history resulted in members of the llocal Llama Super-PAC showing up with tire irons and a strongly worded recommendation that I "should maybe search for something else, if you know what's good for you." I know what's good for me. So I stopped searching. ## for the llols Maybe adults thought that doing this, as a national-llevel prank would amuse their children. The llevel of tomfoolery here is epic, to be sure. Much llike the Great Pumpkin, Santa Claus, and other holiday traditions, the history here is a bit murky. But rest assured, somewhere at the root of this, you'll find the llama super-PAC. I just know it. But that's okay. Llaugh along with the 43-year-olds. I'm sure no harm will come of it. ## The llama Super-PAC[source](https://www.youtube.com/watch?v=djKPvXDwXcs) When the moose super-PAC was disbanded in 1975 by Monty Python, the leaders regrouped, quietly in a dark pasture somewhere nearby, and formed... *The llama Super-PAC.* It's been all llamas all the time, since then. But never fear-- oh no. Those men with the tire irons are back. **I've obviously said too much.** [Answer] Mankind is beset by an insidious virus. Its modifications to the host's DNA are virtually undetectable. In the time it's taken for us just to realize the virus exists, it's already infected every living human. These changes are folded into a part of our genome that's always transferred completely to offspring. Attempts to remove them have all failed disastrously. The entire human race is irreversibly infected. The effects of infection only manifest in response to certain biological events occurring specifically during the 43rd year of life. I won't go into the gruesome details here, and ultimately they don't matter because there's fortunately a viable form of relief: llamas. By simply spending a short time in the company of a llama just as symptoms begin to manifest, the effects of the disease are negated. The most worrisome of these effects are quite brief, only lasting a day or so, but some individuals experience long-term discomfort lasting several months or more. It may be necessary to keep a llama for as long as a full year to ward off the unpleasant effects of the disease. The llama's ability to fight the effects of the disease is an as yet unattainable holy grail to pharmaceutical companies. While the mechanism is fairly well understood, the technology to faithfully reproduce its effects simply doesn't exist. It will be a long time before an artificial, more convenient alternative can be safely, reliably, and affordably developed and manufactured. This has led to explosive demand for llama companionship. The private llama industry has erupted, and llama prices skyrocket despite the best attempts at regulation. There are also the worsening issue of llama abandonment as people irresponsibly buy llamas purely for their healing qualities and then discard them on roadsides, leaving them to fend for themselves (typically at great cost to the local environment). Already reeling from the tremendous expense of hiring llama cowboys en mass to wrangle the growing herds of abandoned llamas, and concerned for their poorer citizens who are forced to suffer the terrible effects of the disease as they can't afford now-expensive llama therapy, more and more governments are taking on a stance of direct intervention. Government subsidized llama ranches now offer rental services, even offering free rental and expense coverage with medical necessity. A government llama is likely to be less than ideal, but serves its purpose well enough. This has not only solved all llama-dependent medical crises, but also stabilized the private sector once more as private llama vendors now compete with the government's minimal baseline by breeding quality specialty llamas for ever more-desirable traits such as portability and diversity of appetite. Many young people, and conservatives of all ages, tend to complain about the resulting increased taxes, but since nobody has any better ideas the slight financial discomfort of all is generally considered an acceptable preference over the otherwise terrible fate of those who most benefit from it. [Answer] **Why is there an Easter Bunny that lays eggs filled with candy? And how is that connected to the ultimate sacrifice made by Jesus?** Why is a fat man living with a bunch of fairies? And isn't it a bit suspect that he lives on the north pole and rides around in a sled giving toys to children? How is that connected to the birth of Jesus? Many rites in the modern world are absurd. The cases above are the fusion of old traditions with religion and then mashed unrecognizible by capitalism. Can you answer the above questions? I can't! *So you don't really need a reason*. The world is full of absurd rites that most people are ok with and where they don't know why they do them. "It's tradition!" seems to suffice. [Answer] International superstar, Alice Dunderhead, gets widespread attention when she shows up at the 67th annual Inane Awards with her pet llama instead of a dog or cat(it had become fashionable to attend with one's pet.) In the dozens of subsequent celebrity interviews, Alice swears that her llama is the source of all joy, reduces stress, improves her love life, and slows the signs of aging. Immediately, every A-list celebrity is sporting their llamas. Soon, llama-keeping is next big thing in all upper-income homes. Television shows popularize it further. Pop music celebrates the purity of llama's love for their keepers. Llama-keeping creeps lower and lower in the class brackets. Since llama-keeping isn't cheap, a disparity emerges between the haves and have-nots. After much debate about fiscal responsibility, equality and pax-llama (i.e. the inner peace generated by being around llamas for a least a year) the government acts. The age of 43 is picked because 42 was too much like [Hitchhiker's Guide](https://en.wikipedia.org/wiki/42_(number)#The_Hitchhiker.27s_Guide_to_the_Galaxy). The law is made to be universal to prevent the have-nots from feeling singled out, and as a bone to the lama industry, who are trying to increase market share. [Answer] Prostate Cancer It turns out that llamas are almost always carriers of the *Toxoprostmosis* bacterium, which, in humans, suppresses prostate cancer so effectively that the AMA doesn't *even recommend* prostate exams for guys who keep llamas for a year. 43 is just a nice middle-aged age for doing this so that it's maximally effective. It's not necessary to kiss the llama or anything, just be around one. [Answer] One politician wanted to prove to a very wealthy lobbyist that his skill in congress could get any law passed in order secure that lobbyist's financial support. The passing of the related law is his proof of ability. [Answer] A bit late to this, but here we go. **TL;DR**: Politics. What was intended as a test program for a few thousands gets unexpectedly popular. By the time politics align to get rid of it, it is to popular to touch, and much to expensive to expand. ## Background So there is a report, based on lots of research, that getting an animal between the age of 35 and 55 is very beneficial to the individual, and therefore to society. [Note: this may even be true. *There may even have been one!*] It makes the caretaker move more! You meet new people and make new friends at an age where that is not so easy. If you have children it is good for both their health and their development. The list goes on - there are lots of benefits! Few disadvantages! Clearly the government should be supportive of middle aged people getting an animal. And in principle that is something everyone can get behind. But exactly how? And so we get to politics... ## It's complicated - and expensive There is this faction that thinks getting an animal should not be dependent on the person’s income. Why should only rich people get a better life!? The government should pay the full cost of having an animal! There is this other faction that thinks that a small tax break for all would be best. Some think all animals and pets should be allowed, others want only animals with a scientifically proven effect over a certain threshold to be included. (There is no agreement in the later group on how high that threshold should be.) What should the lower and upper limits on age be? How about married people - should they get support while either is in the supported age interval? Or do both need to be inside? What about people that already have pets when they reach the lower age limit- should they be supported? Or are only people getting an animal covered? Actual policy is hard! The list of things that needs to be resolved is long! And we are not even at the big thing: COST. Because any sort of support will cost money. And that money will be need to be found. Supporting all pets from 35 to 55, even with a modest amount, would cost more than the government spends on infrastructure and housing combined. So that is out. In fact cats and dogs are not possible either - there is just too many, finding that sort of money is not possible. Not to mention horses - lots of them around, and very expensive. ## But money can be found for something ... In the end a compromise is found. Any citizen will receive support for a Llama while they are 44 years of age. Llamas was one of the animals with the best effect. (This is later shown to be a statistical artifact, but by then it does not matter.) More importantly there are not that many around, so it will not cost that much regardless of how many would like one. And while no-one says this, a Llama is not the most convenient animal to have, so this should keep signup low. And the costs covered are stingy, so it should not be possible to make much of a profit to provide Llamas, preventing Llama speculation! So the law goes into effect. It is marketed as a trial - if it is successful it will be expanded, if not it will be canceled. But due to some arcane budget resolution rules and the way it was bundled with other stuff in the budget it was passed as a benefit that the government needs to cover regardless of cost. No-one cares much about this at the time. “Llamas at 44” is a small sum compared to other stuff and projected to stay that way. ## ... which turns out to be unexpectedly popular. But once the law goes into effect it turns out to be fairly popular. Not wildly, that will come later. But more popular than expected. And Llama breeders all over the world suddenly see an opportunity, and avert the expected Llama shortage. It also turns out that renting/leasing people their 1-year Llama is - as designed! - a lousy business, lots of people are generous with the Llama provider, in particular when delivering the animal back (Would you like to give your Llama a three-month free range mountain vacation before the next person takes over? Of course you would, if you can afford it!), so there are some money to be made after all. (Unexpected tax-avoidance thing having to do with how Llama refund is structured is also promising in explaining how the Llama provider business took of much more than expected.) This concerns some people, but none of those who voted for it wants to reverse course so soon and seem a flip-flopper. Much better to wait a bit until the initial enthusiasm have died down and scale the program back. And some of those very much against it, now sees that some government-supported Llama jobs will not hurt their chance of reelection. And honestly, while it is now projected to be more expensive than initially, it is still pocket change. Why create lots of trouble for yourself now, when it is likely that once someone have been killed by their Llama the voters will be in favour of removing the program? Finally there are much more important battles to fight than Llamas. Llamas can wait. And so one year of Llama program turns into two, and three and four. By now it is really getting popular and costing LOTS of money. But gridlock means that the votes to change it cannot be found. Perhaps a compromise could be found, but the no-Llama faction shows no interest in a compromise with the less-(expensive)-Llama faction. Without that the program continues unchanged. ## Why it is not removed So it takes 13 years from the first Llama was handed out before no-Llama has control of the government. “Less waste” have been their election slogan, and while no-one said that Llamas needed to go - indeed many of them promised the opposite - they now make clear that the government have no role in Lllama-support and it will be canceling the program ASAP. But it turns out the program is very popular. There is the 9 year old that comes to a town hall meeting and begs her representative to vote no. They were getting a Llama next year and without government support they cannot afford it. It is so genuine and precious; it is the viral sensation of the week. There are a surprisingly large number of men in their early forties that are enraged that their supported Llama will be taken away. Variations of “I paid for all those Llamas - I want mine!” are heard by phone operators for no-Llama representatives all over the country. Children and young adults have been looking forward to their Llama. Grandparents thinks it is idyllic that their grandchildren can have one. Polls indicate that women in particular thinks Llamas make the country more real, more like it should be. Whatever that means, making the country less like it should be does not seem like a winning reelection strategy. And the Llama Association (aka BigLlama) have been fearing this since it was started. If Llama support is withdrawn an enormous amount of jobs will be lost (all of that money is after all going somewhere) they warn. There are more jobs in Llama than the automotive industry! More than half of all Llamas would need to be put down in the first year! They have been collecting the mailing addresses of Llama loaners for years and sending out a personal card with a picture of the Llama they had most recently. Now they send out an extra card with “This may be my last card, representative N N does not think anyone new should get to love me”. Even if polling shows many agree in principle that Llamas are a bit of waste, it takes a principled person to support no-Llama when the Llama your father had when you were 12 is about to become sausage. So getting rid of Llama support is no longer on the agenda. For a while Llama reform is being discussed. Trimming the program in a way that saves real money without being really impopular is not possible. Including cheaper animals like dogs are discussed, but modelling shows that lots of people would still get a Llama, while additional people would get a dog, so that it may end up more expensive! Also BigLlama is very much opposed, and it would shift money from rural Llama jobs to dog owners which is not an election winning strategy for the no-Llama faction. ## And why it is not expanded A few years later a Llama friendly government takes power. It considers expanding the program. Perhaps 44 and 45 year olds? But it would be very expensive, and most people that have a Llama seem happy with the one year limit. Sad to give their Llama up yes, but also glad that their Llama year is up. Expanding to more animals are considered, but are rejected for much of the same reason that no-Llama did. Letting people select a year between 40 and 50 to have their Llama is trialed in certain areas. But it turns out that makes many fret over if and when to have their Llama, rather than being excited or not for their 44th birthday. Changing the age to 42 is discussed, but it would create chaos in the Llama industry during the transition, and some would be upset since “42 is not the right age to have a Llama” as one voter stated when this came up. Lots of small things are changed. But nothing major. Which means we are where we started: **The year you are 44 the government will support your Llama.** Note: Having written this, I realize that it has similarities to what is going on just now regarding health care in the US. This is mostly incidental, as this sort of process is more-or-less builtin to any new entitlement. I have opinions on the government’s role in providing health-care, but I don’t mean to express them by this piece of writing, and don’t think I do. [Answer] An ultra-green initiative to mow lawns without using any fossil fuels. It sounds silly, but O'Hare airport actually mows its lawns with llamas (and other animals): <https://www.usatoday.com/story/todayinthesky/2013/08/14/ohare-airport-turns-to-barnyard-animals-to-mow-its-grass/2651645/> If you're going for a darker tone, scarcity rather than conservation could be the motive for energy-less mowing. [Answer] I think the simplest answer is that, in the past, each citizen was paid to raise a llama all their life. Eventually, a politician decreed that nobody under 44 (43?) was responsible enough for this task, and so a lower limit was set. Then later, perhaps many years later, another politician decreed that anyone over 45 was too infirm to handle a llama, and so a higher limit was set. Maybe it was a single change each way, or maybe it was a gradual process (consider how retirement age keeps slowly increasing in our world) The biggest issue with "being paid to care for a llama for a year" -- believability-wise, is that we're going from [never interact with a llama] to [very specific interaction with a llama]. By making the change gradual, and in the other direction, it's more believable that people would just accept it. [Answer] You want the least change needed? How about: When Theodore Roosevelt was hunting in central and south America, he fell in love with llamas. Once he was president, he added a law saying that everyone had to own a llama during their 44th year. This would have had minimal impact since the average lifespan was lower then and most people who lived to 44 years old were well off. The majority of the people would have seen it as a joke on the rich. [Answer] The llama is on the country's coat of arms, as it is for Peru. Cultivating llamas is seen as symbolizing national or planetary pride. The retirement age has been lowered to 44, due to the increasing pressure from technology and automation. So they pass a law allowing one to take retirement benefits one year earlier, if one keeps a llama for a year. [Answer] Subsidization of the Llama industry The llama industry boomed after the trend of llama burgers became popularized. It basically replaced beef and became super popular until the FDA issued regulations against the overconsumption of llamas. Now the llama farmers are left with a huge surplus of llamas and basically nothing to do with them. So the government instituted the llama year thing as a way to protect the llama farmers from losing their jobs and tanking the economy, and to handle the surplus of llamas. It's similar to how the government buys up tons of crops to protect crop farmers, although unlike crops, you can't just legally store llamas away for years and years. Hence, the government sends the llamas to the people on their 43rd birthday to take care of them. [Answer] Obviously, for personal protection... With unanticipated psychological benefits. Studies have shown the age of 43 to be a key vulnerable point, precursor of midlife crises. Llamas are well known for their tendency to protect the pack they find themselves in. So they get a vulnerable population safely through a weak stretch, where emotional issues often leave them open to outside predation. And llamas are more cuddly than guns and knives. Just no comparison. Installing a llama at that key moment gives citizens both a physical and an emotional security boost, smoothing them through the very real dip in emotional and physical strength. Immune system and relationships benefit due to decreased stress. Llamas protect fiercely in the short term, and the psychological boost with attendant health benefits lasts a lifetime. [Answer] In the face of worldwide population increase, this country (very much like Europe) is experiencing a population decline. Technology and the desire to work or pursue other interests has reduced both steady relationships and the average number of children per couple. As each generation ages, cohorts of every same age group are dying off- from medical reasons, accidents, or drunken showmanship alike. Economists and the zeitgeist have seized upon a startling fact: the human decline per age group and resulting population count at age 43 perfectly intersects the count of the balanced llama population. Llamas, while generally respected by the humans, had gone largely unnoticed as pets until this fact was pointed out and popularized by a particularly motivated zoologist. Motivated emphatically, as a matter of fact, by his wife being quite vocal about their own family's burdensome llama, who insisted on eating her roses. The population of recreational and working llamas, even after adjusting for everything from their own birth rates, average lifespan, and fascinating advancements in llama medicine, perfectly matched the human population of age 43. Therefore, the llama "status quo" could perfectly match the number of 43-year old human owners (comprising single, coupled, and polygamist households), but not on one year of either side of that human age, as the peer population declined. It was the perfect intersection of both humans and animals on the planet. The harbinger of death- aging- was fought back by hope for the future; finally, society could jettison the fear of the unknown and take comfort in the almost new-age love for balance on the planet between species (if only between humans and one particularly lucky camelid). If the country's 43-year olds would all agree to host the ownership of each llama for one year as they attained and waned from the perfect age (for owning llamas), the zoologist could trailer Dolly off to a welcoming home along with the rest of the country's herd and improve his strained marital relations in lockstep with the condition of his wife's garden. Therefore, as the fact evolved from a esoteric discovery into the welcoming grasp of public consciousness, the public adopted the practice of trading llamas from newly-celebrated 44-year-olds down to newly-celebrated 43-year-olds. Over the course of the year, as the excitement of their friendly, pleasant new pets faded into the tedium of daily coat combings, bizarre "mwa" vocalizations (mostly by the llamas), and the always-unwelcome spitting for dominance (mostly by the humans), the willingness to trade the animals away at the end of the yearly stewardship was always forthcoming. The government stooges, desperate for reelection and the public's good graces, pounced upon the opportunity and tax incentives were hastily signed into law. The Individual Llama Stewardship Act, or the hackneyed nickname it became known by among conservative news channels, "A-Llama-Care", was signed into law among great cries of "everybody knows that the herd is the word" and other unforgivable bad puns. [Answer] I don't really have any new explanation, but I do have several side effects that keep popping up in my headcanon that wouldn't fit in a comment. I can imagine ridiculous circumstances arising such as... * a rising surplus of llamas due to falling birthrate ("Millennials are killing the llama industry!") * a 24/7 llama channel on cable (reality shows, shopping programs, Llamas 101...) * your friend who's Kickstarting a no-kill llama shelter for those who've been lost in the system * vets whose focus is in-home llama visits * PETA protests and anarchists organizing large-scale llama breakouts * workplaces with llama-related leave policies or even llama sabbaticals for the dedicated few * lawyers who specialize in llama-related litigation (billboard/television ad: "Does your llama need medical care? Is the government refusing you compensation? Call Bob Smith, the Llama Lawyer! 1-800-LLAMA-LAW") * the new go-to excuse for kids is "The llama ate my homework!" * op-ed pieces or women's magazine articles with topics like how to handle a llama spitting faux pas * this season's hottest llama wool fashion (much like the organic craze, classier stores advertise "free-range" llama sourcing) * every so often, the news features a high-stakes forced llama reclamation for those who've had their llama care privileges revoked * banks offer a special savings account for your llama year * there's a government department that deals exclusively with llama policy, allocation, and distribution (imagine how top secret llama-related clearance would work...) ]
[Question] [ While exploring a dwarven/dwemer ruin in Skyrim, it occurred to me that the puzzle I was solving made no sense: a series of levers accessible from the direction of the entrance that each caused a wall of spikes to give way to the next lever. This kind of system can't be used for defense, since the invaders have free access to the levers, though it could slow them down (slightly). But the broader question is: Assuming it isn't creating puzzles for adventurers to solve years later (or because a software company directed such), why would a society fill its factories, cities, fortresses, etc., with puzzles, (e.g., levers, switches, doors with puzzle locks)? [Answer] Perhaps the puzzles are not really puzzles *to their creators*. Imagine someone approaching a real-world house ... * First, find the key in the hiding spot on the front porch. * Next, release a lever to open the fly screen to reveal the *real* door. * Then insert the key in the lock of the door and turn. As all legitimate visitors know, you have to wiggle the key a bit to make it turn. * Turn a lever next to the the key slot to open the door. Turning that lever first would have no effect. * Try to find the light switch in the dark. Everybody knows that the switch will be next to the door case, slightly below shoulder height. * The final puzzle is the burglar alarm. To disarm it, find a box on the wall several steps after the doorway, open it, and type a passcode. With luck, the code can be derived from the birthdays on the wall calendar. Completely logical, right? Only medieval dungeon crawlers would call that a fiendish sequence of puzzles. [Answer] The key issue here is gaining access through solving puzzles. This could be because whoever built the place wanted people to gain access to whatever was inside, but only the *right* people. In a slightly more "realistic" setting, the puzzles might be based off the teachings of a religious or philosophical sect, so only initiates who really understood the religion or philosophy would be able to solve the puzzle and reach the next stage. This would also keep the internal workings of the sect private, much like the modern Masons, where you cannot reach the next level until you understand the rituals and teachings, you are not going to reach the inner sanctum and speak to the high priest unless you can solve all 22 levels and beat the gatekeeper in a lightning round of chess. As for the unbelievers, well crocodiles need love and attention too..... If the religion or philosophy was either very arcane, had a very limited distribution or had become extinct, then explorers coming across the ruins will find a very strange set of traps with no discenable purpose, and members of the party are being fed to the hungry mutant sea bass at seemingly random intervals. So putting puzzles in dungeons or other settings *could* actually be to serve a screening function, and ensure only the right people got in, and the *wrong* people were (rather violently) screened out. [Answer] **TL;DR: To slow the intruder down.** Step back in time for a moment and imagine you're one of the Dwemer. You need a way of being able to access a room that makes it hard for other people to get in. You could put up a gate with a lock, but this has several major flaws: 1. People in Skyrim know how to lockpick. 2. People who need to enter the room need a key. 3. People who want a key can pickpocket someone who has one. 4. People who want a key can kill someone who has one. Now consider putting up a system that requires people to move levers around in the right order: 1. Cannot be lockpicked. 2. No need to forge a new key every time. 3. The correct order cannot be pickpocketed (unless written down). 4. People who want a key would have an incentive to keep you alive. Someone could figure out how the system works, but remember at this point in time the mines are still fully operational. That means there are Dwemer walking through the corridors all the time, so the longer an intruder takes to figure it out, the higher their chances of being spotted are. These are the same reasons for why people use combination safes instead of safes with keys. Now look on the other side of the coin, imagine that humanity died out and the apes took over. You are now an ape trying to break into fort knox. Fort knox stopped being manned centuries ago but the ruins still stand. It would take you a while and you might need some heavy machinery, but you'd eventually break in. When it comes down to it, all security systems are just delay mechanisms. Even passwords. Given enough time, a program set up to brute-force your password will find the correct password eventually. The idea is to make it take an implausibly long time to brute-force, not to make it impossible. [Answer] To answer the broader question of "Why puzzles?" In other series (Zelda comes first to mind), the puzzles might be a test to make sure that the Hero is worthy of the prize. Wonderfully deconstructed by Awkward Zombie: [![Sliding Scale from Awkward Zombie](https://i.stack.imgur.com/VaQk2.png)](https://i.stack.imgur.com/VaQk2.png) [Sliding Scale from Awkward Zombie](http://awkwardzombie.com/index.php?page=0&comic=111212) [Answer] "[The Doors of Durin](https://www.youtube.com/watch?v=JzQdW3RUY5g), Lord of Moria. Speak, friend, and enter. I, Narvi, made them. Celebrimbor of Hollin drew these signs." This is a famous example of a "puzzle" that nearly stumped a very wise wizard. Yet, it was not meant by its builder to be an insurmountable obstacle. It allowed free access to those who understood what was required, while simultaneously imposing a deterrent to those beasts or persons that did not understand. So I would concur with the idea that a solvable "puzzle" is not inherently unreasonable. On the other hand, the plausibility can be lost depending on the details. As a comic given in another answer indicates, if it would be a serious loss for a known foe to gain access, it does stretch matters beyond reasonableness if the puzzle is solvable even by that known dangerous foe. Durin's Door is not an example of this failed case. It was a plausible puzzle for reasons recognized and explained in the story -- after the puzzle is solved. [Answer] It's a [Folly](https://en.wikipedia.org/wiki/Folly): > > In architecture, a folly is a building constructed primarily for decoration, but suggesting through its appearance some other purpose, or appearing to be so extravagant that it transcends the range of garden ornaments usually associated with the class of buildings to which it belongs. > > > Examples: [10 Extravagant Buildings That Serve No Purpose](http://twistedsifter.com/2012/10/follies-extravagant-buildings-that-serve-no-purpose/) The point of the puzzles was never to be difficult, but rather that there was someone sufficiently rich who thought it might be sorta cool. [Answer] **Spoilers for the D&D module *Tomb of Horrors* below.** In the (in)famous Dungeons and Dragons adventure, the *Tomb of Horrors*, the tomb in question is known across the land as being very hard to navigate, filled with deadly traps and puzzles, and home to a hoard of treasure. Adventurers turn up so frequently to attempt the tomb that a town has sprung up around the entrance, filled with businesses trading in weapons, healing potions, and general adventuring supplies. In fact, it turns out that the powerful demi-lich Acererak created the tomb, the traps, and the stories about it, all in order to attract adventurers. The traps and puzzles are lethal in order to scare off, kill, or otherwise prevent the weaker among them, ensuring that only the strongest will make it to the deepest extent of the tomb... where Acererak will harvest their souls in order to increase his own power. He doesn't want weak souls because it's a difficult process and not worth wasting, and if too many adventurers make it through, he'd be too tired or busy to deal with them all, meaning that some of them might get lucky and actually manage to kill him. The whole place is therefore designed to kill *most*, but not all, leaving him with a steady supply of souls that are worth harvesting. [Answer] One answer I've seen in literature is to set up a convincing illusion to disguise the deeper secrets of the building. In his book Bands of Mourning, Brandon Sanderson presents an interesting twist on the typical dungeon filled with puzzles and traps (major spoiler alert). The characters run into a stereotypical set of pit traps, acid traps, swinging weapons, tile-activated traps, etc. All of this supposedly protects a powerful weapon. However, the characters don't find this entirely logical. > > "The ones who built this place were charged with protecting the Sovereign's weapon. They knew others would eventually follow, and so the builders were bound to make it difficult, knowing that they could not remain to guard in person..." > > > "Why would your people build such an obvious resting place for the Bands? Why make this temple, which proclaims thatsomething precious is inside, then go to the effort of making all these traps? Why not just hide the Bands someplace unassuming, like a cave?" > > > "They are a challenge, like I said..." > > > "You told me the sovereign left his weapon there with order to protect it because he was going to return for it, Right? ... Wouldn't they have been worried for your king's safety?" > > > Unfortunately, the logical place for the prize appears to have already been looted, but they realize the traps and fake treasure room were only to fool them and make them think they had solved the challenge, when the weapon was hidden elsewhere. They then find a hidden side chamber with what appears to hold the real weapon. > > "Those traps... those traps are stupid. What if one did catch him? > The whole things has to be a decoy..." Since the weapon was easy to > hide, "only someone who knew what to look for could use your weapon. > And in that case, the people who built the temple could have left the > weapon where the returning Lord Ruler would see it, but everyone else > would pass right by, digging farther into the temple to encounter > traps, pits, and decoys, **all designed to either kill them or convince > them they'd successfully robbed the place**" > > > It gets worse, though. (Serious *Mistborn* spoilers ahead. Read at your own risk!) > > The "real weapon" they find in the side room is without power, leading them to believe it's already been used and then returned here, depleted, without recharging it. It's not until later that they realize it's yet another layer of fakeout for extra-determined looters! The actual weapon was shaped differently than what they expected it to look like, and placed on a statue outside of the dungeon, where its owner could come to retrieve it without having to deal with any hassle at all, but other people would easily overlook. > > > > > This all makes a lot more sense at the very end of the book, when Waxillium finds a stored memory revealing that the Sovereign is not, as they had assumed, a reincarnated Lord Ruler -- for whom all this stuff would have been quite out of character -- but actually a reincarnated *Kelsier,* a rebel against the Lord Ruler who loved messing with people's heads and fits quite well into the trickster role. > > > So in summary, the puzzles can be a distraction to stop you from digging too deep into the secrets or the place and feel like you've explored enough. They set up a linear route down the path which a clever designer can use to give the user tunnel vision. [Answer] ## Maximum Security for Secrets If you have valuable secrets, you want to defend them with as many levels of security as possible. Maximum security can be achieved with: * maximum number of guards * many obscure, puzzling blocking mechanisms * hiding all parts of the secret deep in unlikely places ## Well Guarded The more human guards around your secret, the more likely intruders will be spotted before they discover the entrance to the secret path. To ensure maximum vigilance around the secret, place it where many sentries are already supposed to be constantly vigilant for obvious, non-secret reasons. What better place than a heavily guarded dungeon inside a heavily fortified castle? ## Puzzling Blocking Mechanisms Relying on Arcane Principles Another type of security is placing a blocking mechanism between thieves and your secret. Simple locks opened with keys, being relatively common mechanisms, could be familiar enough to thieves that expert lockpickers could pass through them all too easily. Therefore, blocking mechanisms employing obscure, puzzling principles would be essential in foiling would-be plunderers: * Each successive puzzling blockage increases the likelihood invaders will not be able to solve at least one of the puzzles * In addition, if each puzzle requires a significantly different style of thinking to solve, it further increases the likelihood invaders will at some point not be intelligent enough to solve them all ## Hiding Hiding access to the valuables is another way to prevent them from being found. It is almost the opposite of a blocking puzzle--here the puzzle is simply "why would I look there?" Hiding can take the form of: * keeping the gold in the least likely of places (i.e. in a dank old dungeon, rather than in the most obvious of places--the gilded treasury everyone knows about) * concealing an opening or lever which would ordinarily have been in plain sight (i.e. hiding a lever behind a plate in a room) * placing the hidden opening or lever at a vast distance from the invader (i.e. at an inconspicuous place deep within labyrinthian secret catacombs attached to the dungeon.) ## Hence Dungeons with Long, Puzzle-Laden Passages are Best for Treasure! Thus, a dungeon filled with guards, secret passages and layered with mysterious, arcane puzzles is basically a supermax vault hidden within a fortress, and hence one of the best places to successfully hide your most precious secrets. [Answer] **A test for intelligence** This comes from a scifi novel, but I think it could also apply to medieval fantasy dungeons. A series of puzzles are put in place with the aim of allowing access only to whoever have the intellectual means to get past the puzzles. In this case the puzzles aren't meant to prevent access to the dungeon goodies, but they're merely a test to make sure whoever reaches the goodies are worth of them. [Answer] ## Tombs I think there are two distinct sets of areas to place traps. The first is tombs and graves. Places that hold the dead. The easiest justification for having traps here is religion. The builders believe that at some point in the future the bodies need to be taken away. This is likely to be combined with some mummification process, either Egyptian or Incan. It might even be bog mummies. Now, why do they need to be taken away? Maybe a savior will come that lets all the dead rise and join him on a journey. The savior will be smart enough to solve the puzzle and mere mortal plunderers will be blocked. Alternatively, maybe the puzzles aren't really puzzles, but a mere test for the spirits/souls of the dead. They would see through them with ease. Again, it's us mortals that need to stay out, while still allowing the spirit to reclaim his body at the right time. ## Cities This is harder to justify. Entrances to settlements can be guarded with fake or hidden paths against outsiders visiting. I'm not sure those or a maze would count as a puzzle. Again, religion can be used. Maybe their religion foretells a great end of the world that starts with all of the chosen people dying. But maybe the buildings are shielded against spirits. Lined with salt, herbs or runes, to keep the evil spirits in the dark outside. But now the souls of our chosen ones are trapped inside. Maybe they need guides, valkyries, to take them to the afterlife. Perhaps the intricate locks are made for such divine creatures. Simple mortals and ghosts struggle but, divine beings can easily open them. A completely different approach: maybe they weren't build as puzzles. Their society build a very extensive network of pullies and levers. Opening doors, trapdoors for supplies, adjusting machinery. Now over time things broke. Instead of a well working system it became a broken death trap. Perhaps the system doesn't rely on inorganic cogs and ropes. Maybe it's organic and without caretakers it grew, made connections it shouldn't. Maybe the switch for the door now also open the airlock. A broken one that's now filled with poisonous gas instead of the supposed medical herbs. Again a death trap. ]
[Question] [ Chaos plagues the land. In the West, the King in Orange blusters and bloviates endlessly in barely comprehensible gibberish. Perhaps he is attempting to call forth the Elder Gods? In the East, the Queen of Mayflies glowers menacingly and shakes a vaguely pole-shaped object1 at friend, not foe. The people cry out for deliverance from this turmoil, and one man, the nominal head of an obscure anarcho-syndicalist commune in the countryside believes he has the answer. > > The Lady of the Lake, her arm clad in the purest shimmering samite, held aloft Excalibur from the bosom of the water, signifying by divine providence that I, Arthur, was to carry Excalibur. That is why I am your king. > > > Waterytartocracy is the way forward, says he, the Lady of the Lake told him so. But who, or what, is this "Lady"? --- She, or it, must: * Be able to live in a lake, or at least spend consecutive days underwater in said lake * Preserve one or more European swords of at least arming sword length in good condition underwater for extended periods of time * Possess one or more arms that can pass off as a human lady, preferably with the appearance of being clad in samite * From underwater, hear the sound of two empty coconut halves being banged together near the shoreline, so as to determine the Chosen One Bonus points if she/it: * Actually looks like a human woman or mermaid, or at the very least has the silhouette of one while swimming when perceived from the shore * Can talk to humans, so as to participate in farcical aquatic ceremonies that confer supreme executive power * Breathe, move about, and otherwise function normally(for a human) on shore, also for the purposes of aforementioned ceremonies. No actual magic is allowed. 1: Normally one might expect this to be a spear or scepter, but given the state of total confusion nobody knows what it actually is [Anatomically Correct Series?](https://worldbuilding.meta.stackexchange.com/questions/2797/anatomically-correct-series/2798#2798) [Answer] I suspect that she is a woman. > > * Be able to live or at least spend long periods of time underwater in a lake > > > "Long periods" is relative and opinion based. Kimberly Jeffries can hold her breath for six minutes even after having drank a load of coffee. Also notice that women are easily capable of outsmarting men, 'specially men who do not pay attention to their surroundings. The lady of the lake may dive only when someone approaches, and then she can use a snorkel made of reeds to spend really long periods underwater. > > * Preserve one or more European swords of at least arming sword length in good condition underwater for extended periods of time > > > Doable. I know plenty of women who have swords (I went to a fencing school). Preserving swords underwater would be hard but has been done. The [sword of Goujian](https://en.wikipedia.org/wiki/Sword_of_Goujian) is approximately 2,500 years old and was found in a river without any tarnish. It is believed to have spent 2,000 years underwater. > > * Possess one or more arms that can pass off as a human lady, preferably with the appearance of being clad in samite > > > A human lady clad in samite will perfectly mimic a human lady clad in samite. Also, women generally have woman-like arms[citation needed]. > > * From underwater, hear the sound of two empty coconut halves being banged together near the shoreline, so as to determine the Chosen One > > > As long as she is not deaf, that is a no-brainer. You can experiment yourself if you have access to a pool, a friend and a coconut. --- Now let's see if I can collect a bonus. > > * Actually looks like a human woman or mermaid, or at the very least has the silhouette of one while swimming when perceived from the shore. > > > You would be surprised to find that women look like women. > > * Can talk to humans, so as to participate in farcical aquatic ceremonies that confer supreme executive power > > > For the vast majority of people throughout space and time, the first word they learned is "mommy" in whatever their native language is. This is usually taught by a woman, with most of your early vocabulary being learned by imitating her. I think this is enough evidence that women can, in fact, not only talk to other fellow humans, but also teach them how to do so if required. > > * Function normally on shore, also for the purposes of aforementioned ceremonies. > > > I am yet to see a woman fail to function normally on shore. Men, I've seen or read about plenty ([Jackass](https://youtu.be/rIcOI1WqGtM) and [the Darwin Awards](https://darwinawards.com/darwin/darwin2001-19.html) have a large set of examples of our shorely disfunctions), but women? Nope. [Answer] **She is a normal woman standing in a submerged bin** While she awaits the chosen one she sits on the stool. As soon as she hears the coconuts, she stands on the stool and arranges her samite robe to conceal the edges of the bin. She raises the sword aloft and waits for the future king to appear. [![enter image description here](https://i.stack.imgur.com/9Rgbq.jpg)](https://i.stack.imgur.com/9Rgbq.jpg) Clearly there are variations. She could remain sitting with the samite already in place and simply raise her arm with the sword at the appropriate moment. She could have peepholes in the samite. --- **More complete diagram** [![enter image description here](https://i.stack.imgur.com/wpgth.png)](https://i.stack.imgur.com/wpgth.png) [Answer] [Did you know some turtles can breathe through their butt?](https://en.wikipedia.org/wiki/Cloaca#Cloacal_respiration_in_animals) Here we have a similar thing: a humanoid lady clad in long folds of her own skin, which just so happens to look like samite. Which, after some googling is apparently some kind of embroidered silk. This species has a peculiar mating ritual: the males migrate over land towards ancestral spawning ponds and upon arriving there will tap together sticks (or similar objects, such as coconut halves) in a rhythmic fashion to entice the female to rise to the surface. The female in turn presents the male with an object of choice. In a natural environment this is usually some kind of plant, shell, bones or even a dead mallard. In areas where humans are present the mating ritual will often involve either human detritus or even some votive offerings made by pagans in ages past. Arthur is just quite blind, his servant very polite and the amphibian lady very desperate for a mate. [Answer] [Manatee](https://en.wikipedia.org/wiki/Manatee) are believed to have given origin to the myth of the sirens: their swollen breasts while breast feeding their younglings, their humanoid appearance, the human sounding sounds they can emit, together with the months long forced heterosexual abstinence experienced by old time sailors, could easily explain the "chanting naked ladies luring sailors to death with their voices". Well, take a manatee adapted to lake or river life, and have it put out of the water a sword, which happened to be on the lake bed, right when a coconuts holder is passing by. Some gentle moans of the manatee can sound to the ears of the adventurers like an invitation for a holy mission, of course said in a heavenly language not understandable by commoners. [Answer] **The poor man had terrible visibility and was a braggart.** No one was actually there. He came upon the remains of a sacked merchant cargo at twilight. The cargo, including [thick samite tapestries](https://en.wikipedia.org/wiki/Samite), was dropped, clumped and draped over debris and branches near a bog or pond. It just so happened that the lumps looked like a reclining female form with an outstretched arm handling a sword. Unfortunately, there *were* dead bodies around the booty. So creepy is as creepy does, and no one looked too closely at the reclining form. Imagine coming up to a place that smells of mud, rot, and offal, with the sounds of scavengers being heard throughout the woods. No one wants to linger there. On top of which, very few people would want to set foot on uncertain terrain when visibility is, at best, enough to see shapes and shadows. If I was in their shoes, I would take the closest bit of valuable pickings, which any bit of metal would be, at that time. I would then head straight for the closest village for heat, food and safety. And when pressed for how I got such a valuable item (the sword), I would say "someone gave it to me". The details would come later with every mead-induced retelling. [Answer] > > **In the West, the King in Orange blusters and bloviates endlessly in > barely comprehensible gibberish.** > > > I see what you did there. Here's an idea: the Lady of the Lake was once the Orange King's rival to the the throne. She has been banished from the dominion, or has gone into hiding to avoid being cast into the dungeon by the King's overzealous constables. Thus, she stays in a wooded lake area adjecent to a rebel province, hunting wildlife, sometimes hiding in the water, under the lilies and foliage, to avoid being seen by the King's spies. The Lady of the Lake was once the consort of a past mad king who was long-since deposed. Perhaps she is of royal blood; perhaps she knows dangerous secrets of the kingdom. She is sometimes rumored by her enemies to be a sort of demigod, cyborg, or alien hybrid. Perhaps she knows enchanted spells, or is in possession of a magical or scientific artifact she received as a gift during her time as Queen. Even the Orange King is suspicious that many of his own court are secretly loyal to her. Suppose also that the Orange King was in fact a known imposter, one who claimed to be wealthy but in fact had lived most of his life on borrowed wealth. His army was indisputably smaller than the Lady's, but while her forces were scattered about the coastlines, his much weaker forces were concentrated into the middle of the country, allowing him to put local pressure on the antiquated priestly caste and forcing them to arrange a coronation ceremony in his honor. Whenever a company of knights go out into the woods, they sound their trumpets as they approach the lake. When she hears them, and sees their banner, she silently raises her golden-hilted, gemmed sword above the surface, bearing the ancient national insignia. She thus proves, it is indeed I, the Lady. She communicates from within the water, reflecting light off of the sword as a sort of heliograph, keeping her a safe distance from the King's archers who patrol the frontier. The knights then share her received wisdom with their kin and allies, keeping hope alive. [Answer] At what point in Arthur's description does it say the Lady of the Lake lives in the lake? She could just be a woman who lives in the general area of the lake and exerts control over it. The "ceremony" in the description only says that she was in the water when she gave him the sword. There once was an old hermit lady who lived in a little cabin on an island in a large and deep lake. Once while gathering herbs along a path in the forest around the lake she found a rather nice sword, perhaps unknowingly dropped by a passing traveler. Several weeks later she heard the sound of clapping coconuts from across the lake and knew that brave knights were nearby. The sort of knights who might own a sword like she had found. Her boat was in poor repair at the time so she swam across the lake to greet the brave knights but the sword was rather heavy and she struggled with it. When Arthur reached the shore she summoned her last bit of the strength to lift herself and the sword out of the water but was too out of breath to say anything. Arthur took the sword and was so enamored by it that as he clip-clopped away to his destiny he didn't notice the poor lady was dragging herself onto the shore after nearly drowning. [Answer] **To question a Lady's habits is unbefitting of a dignified man** Aria of The Pond's exhibitionist tendencies to flaunt her water-adorned body under the moonlight is a known phenomenon among the people of the nearby village of Clovelly. In fact, despite her not having any contribution to the village, the inhabitants frequently send her meals in the form of a floating basket, due to her spending the majority of her time submerged under the reeds of the small pond. Understandably, outsiders who spots her meals mistakes them for offerings to the 'Lake Goddess'. The situation also gets worse when it has become tradition for outsiders to throw their perfectly usable swords somewhat dangerously into the pond as an offering for peace. Apparently, the elders describe her as 'easy-going', 'sweet', and 'polite', and 'a sparkling conversationalist', despite nobody having heard her speak at all. In fact, she is so shy that even at the slightest sign of an outsider, she retreats into the depths of the pond, brandishing the discarded swords at the sound of the banging of the two coconut halves she uses to summon her pet robin. Though she does not seem to be overly aggressive, I advise you not to disturh her in any way possible, as the village elders seem to have a liking for her. ]
[Question] [ Yes, I realize this question is a bit ridiculous, and there are no cases of it in reality (that I can find), but with a bit of truth twisting, could it theoretically be possible? In my fantasy world I want a poison, which has an antidote - that antidote being itself. Here's my theory: the substance is very closely related to something in the human body, like a bacteria or something, but has one tiny difference, which is what makes it lethal, and it kills you pretty fast. If a bunch of this stuff is released into your body, would your body recognize it faster, and since its so similar to your body in the first place, could it be easier to neutralize a larger dose, while a tiny drop would kill you faster? Also this is in medieval period before antibiotics. [Answer] Related to [cmaster's solution](https://worldbuilding.stackexchange.com/a/113322/35055): The "poison" is actually harmless A. The body converts A to B, also harmless. The body converts B to C, deadly. Once the A->B path has saturated you get an A->D path. D blocks the B->C reaction. B is eliminated from the body faster than D. While I am not aware of anything with this behavior there are things that exhibit part of it. I don't know if it's still the case but the treatment for methanol poisoning is ethanol. Saturate the reaction path with the ethanol and the methanol doesn't kill you. Also, consider acetaminophen. With the usual dose the preferred pathway produces a chemical that is of little threat. However, there's a second pathway that produces N-Acetylimidoquinone which is a nasty customer. While this is always produced it is usually in small quantities and quickly neutralized. However, the primary pathway can saturate, once it does all the remainder gets converted to the N-Acetylimidoquinone which destroys your liver and thus kills you if you don't promptly get a liver transplant. It occurs to me that if such a chemical actually exists it probably would be unknown. After all, why would you test above the dose that kills all your test animals? And in humans such exposure would be extremely rare. Even if there is a case of unexpected survival it's unlikely they would spend the effort to figure out why. [Answer] What you're looking for is an **emetic** - a substance that induces vomiting. This is the specific reason why, [as @Alberto Yagos already stated](https://worldbuilding.stackexchange.com/a/113299/35055) in his answer, suicide-by-pills doesn't always work - many pills are coated in a small amount of emetic so you'll throw them up if you take too many. In the case of your poison, a large enough dose would cause you to throw it all back up, thus saving your life. A small enough dose, however, would just slowly digest in your stomach, and once it's in your bloodstream, it's lethal. A cursory search hasn't found me any real-life emetics that would kill you if you didn't take enough of them. The closest I can find is copper sulfate, but it only becomes dangerous *way* past the point at which it makes you throw up, and doesn't seem to do anything below that threshold. The good news is, this means you can invent your own emetic poison, and tweak the numbers (how long it sits in the stomach for, how much is required to induce vomiting) until they're just right for your story. [Answer] This is perfectly possible, and I guess it could be readily done with modern technology. For less technical settings, you just need to say that some plant happens to produce the poison, it's believable enough. So how does it work? Your poison needs to be a drug (let's call it P) that targets two different compounds in the human body (call them A and B). Think of a large molecule with two different functional groups, each of which are responsible for one of the two reactions. Such molecules should be quite easy to produce with modern methods. * Compound A is rare in the human body. P strongly interacts with A to produce the evil, deadly compound E. * The evil compound E needs some time to do its destructive work, though. * Compound B is abundant in the human body, but P only weakly interacts with it to form some other compound R. * When compounds E and R meet, the E is destroyed for good. With these traits and reactions, you would get the following behavior: * A low dose of P will mostly interact with A to form the evil E, killing the victim. * A big dose of P will quickly interact with all the A that's available to form E. Once the reservoir of A is depleted, no more E can be formed. The rest of the dose of P then interacts with B instead, forming large quantities of R. The R proceeds to eliminate the E before it can do too much harm. * After a large dose of P, the body will be flooded with R, granting immunity to P for a limited amount of time. --- If you want to optimize, you may also skip the compounds B and R, and have P directly inhibiting E. In this case, the toxicity of small doses would rely on P turning A into E more quickly than it can eliminate the produced E. The non-toxicity of large doses would rely on P quickly depleting A, so it destroys the produced E instead. The two path reaction seems easier to explain to me, though. [Answer] There is one possibility: your lethal substance is an ingested poison. With a low dose, it goes into the bloodstream and kills you. In a large dose, it is so harmful your stomach immediately throws it up, saving your life. It isn't pretty, but it is reason some suicides with pills failed. And as another example, Napoleon tried to kill himself during his exile and he took so much poison he threw it up and survived (to be murdered by another poison later). [Answer] What you're proposing is certainly possible, although I don't know of a case that demonstrates this exactly. The behavior of biologically active molecules (drugs or toxins) can be very complex (see [pharmacokinetics](https://en.wikipedia.org/wiki/Pharmacokinetics) on Wikipedia). Many poisonous substances are detoxified or made toxic by enzymes in the body (drug metabolism). For instance, [ethanol](https://en.wikipedia.org/wiki/Ethanol), the active component of beer, is converted by the liver enzyme *alcohol dehydrogenase* to acetylaldehyde (more toxic than ethanol) and then by the enzyme *acetaldehyde dehydrogenase* to acetic acid (nontoxic and naturally occurring in the body). Drugs that can cause the body to make more of an enzyme are called enzyme inducers. Interestingly, some drugs can induce their own metabolism (for example, the anti-epileptic [carbamazepine](https://www.ncbi.nlm.nih.gov/pubmed/3734137)). This is called autoinduction of drug metabolism, meaning that the drug upregulates the same enzyme that degrades it. In fact, this is one mechanism for developing a tolerance to drugs. So your poison could be a toxin that upregulates its own metabolism. The biological activities of drugs can be very nonlinear, so it is possible to have a situation where the toxic effects of your molecule are fatal at low concentration, while, at high concentrations, it highly upregulates the enzyme that metabolizes it, making it nontoxic before its effects are fatal. I don't know of any molecule that acts this way off the top of my head, but I wouldn't be surprised if something like this exists. [Answer] [Homeopathy](https://en.wikipedia.org/wiki/Homeopathy) is the real world, but ***very, very mistaken***, idea that ["like cures like"](https://en.wikipedia.org/wiki/List_of_Latin_phrases_(S)#similia_similibus_curentur). An infinitesimal amount of a poison can cure the poison's symptoms. For example, [mandrake root](https://en.wikipedia.org/wiki/Mandrake) can cause hyperactivity and hallucinations, so a homeopathic "doctor" faced with a patient with such symptoms might produce a [tincture](https://en.wikipedia.org/wiki/Tincture) of extremely diluted mandrake root. The more diluted the tincture, the more powerful the cure. In reality this is hogwash. Homeopathic tinctures are so diluted statistically they often contain not even a single molecule of the original substance. Homeopathy "theorizes" that the [alcohol or water retains the "memory" of the original substance](https://en.wikipedia.org/wiki/Water_memory), also hogwash. Homeopathy "worked" because doctors at the time would do more harm than good, and the "medicine" came with a long required list of healthy habits the patient must practice. Now it's just a placebo. But in a fantasy world, why not?! Homeopathy was developed in the 18th century, but "like cures like" goes back to [Hippocrates](https://en.wikipedia.org/wiki/Hippocrates) so the concept would be around for a medieval setting. Take the same approach as homeopathy, but now it's ***like kills like***. In Homeopathy, diluting a poison is supposed to turn it into a cure. In your world, ***diluting a cure turns it into a poison***! A large amount will save you, but an infinitesimally small amount will kill you. Perhaps the substance itself is the cure, but the diluted "solution" (in quotes because there's nothing of the original substance left) retains the "memory" of the disease it's meant to cure. [Answer] One possibility is that the substance binds to itself in large amounts but not so well in smaller amounts. Since it doesn't bind as well in small amounts it's able to interact with the body more so in those small amounts. It's poisonous in both situations, but significantly more so in small amounts. The best description I can think of is this; a thin layer of metal isn't very strong when stressed (like a chemical in a body would be) so it breaks with very little force into small pieces compared to a thick layer of that metal. It's been too long since chemistry class, so I can't say how accurate this description is. [Answer] You're missing a couple of elements here. ***Effects vary depending on delivery method.*** If the substance isn't readily digested, you might need large quantities to get any of it into the victim's system. In the extreme case, it might be completely ineffective that way. Taken in some other form - injected into the bloodstream, for the most obvious example, but more recently using coated microcapsules - you can get that substance to where it works. ***Effects vary depending on surface area.*** A bit of gravel stuck in a nostril is an annoyance. The same rock ground to a fine powder and inhaled over time gives you silicosis. Nanoparticles appear to have different characteristics to larger bulk stuff. So smaller amounts *can* be more effective - but you'll need to use it differently. [Answer] # Drugs. We already have what you describe. When you're addicted to some substances, you can't simply "just stop", that'll kill you as your heart will fail. You will need to get close to the average dose of a person and slowly lower the dosage. In you case, the drug could be with less/no additional effects, but when stopped, you die because your body no longer produces whatever is in the drugs. You could make it a food suplement, or as assasin introduce it slowly into the waterstream and threaten to stop. [Answer] Two other solutions, but with some statistic : 1. A plant which produce 2 kinds of berry : one is a powerful but slow poison; the other is a an antidote which is more powerful than the poison: one antidote berry is enough to cure two berries of poison. You can't differentiate between them with medieval technology. So, statistically speaking, the more you eat the fruit, the more chance you have to find a cure for the poison you ingest. 2. The fugu is a fish delicious if we'll prepared but deadly if a mistake is made. You can create a fish which is its own antidote if well prepared. And same thinking as the solution above, you have more chance to live the more you eat the fish. [Answer] Napoleon's attempted suicide by [Arsenic](https://en.wikipedia.org/wiki/Arsenic) comes to mind, legend has it that he thought himself so great a man that he took several times the lethal dose for a man his size; instead of dying he puked it back up and lived to tell the tale. It's not that arsenic is necessarily less poisonous in very large doses but the body is better at realising it's in trouble and rejecting the material. The Calabar and Castor Bean can both appear more lethal in small doses because if swallowed whole they don't release their toxins but if chewed, especially the Castor Bean, they can be deadly. [Answer] I'm going to go with a different answer and say **disease**. There is a phenomenon in the bacterium kingdom in which an action can be executed collectively by all bacterium once a certain population is attained. the big example is luminating: [![enter image description here](https://i.stack.imgur.com/fZfcK.jpg)](https://i.stack.imgur.com/fZfcK.jpg) Theoretically the smaller the dose of a deadly bacteria that one ingests, the longer it would take to die, and thus be harder to track, and harder to treat early. [Answer] Maybe **oxygen**? With a limited amount of oxygen it is definitely more lethal, but it doesn't really fit into the poisons part. Unless you consider the part where some say it is actually just killing us very slowly. And how some consume antioxidants to keep their skin youthful, etc [Answer] For a slightly different twist, that may still stay compatible with your world. A plant can contain multiple poisons. The deadly poison in small doses is undetectable, It's medieval time, there is no bloodtests, just showing symptoms, you show 0 symptoms until it's too late, then you die, but it takes a long period to metabolize. In larger dosages, you start to process the well rumored hallucinogens well before your body has time to metabolize the poison. You recognize the legends / rumors / specific hallucinogens that are related with this plant, and know that you must remove it from your body ASAP to have *any* chance of survival. It's not that a larger dose is necessarily an antidote, but is the only way to know that you have ingested it and take action consciously. The fact that small doses are still lethal and undetectable, is probably a secret known only to assassins. [Answer] The two best voted answers gave me the idea of using a catalyst... Catalyst C quickly converts all available Vitamin Q (found in fruit H consumed widely in the land) to deadly Poison P. In large amounts however, the catalyst sits on the receptors and blocks Poison P from acting, until they both are safely removed from the system. This works because P is eliminated faster from the body than C. An interesting side effect is of course that your skin turns a bright shade of green while P is still in your system. Now, you need to be very careful not to eat any of that tasty fruit H until you're back to your usual shade of beige. This trick of turning vivid green is widely used by the tribes in gaba-gooba land to help them with hunting and stealth attacks on rival tribes. However, vitamin Q deficiency is wide-spread, leading to short statures and a tendency to wiggle uncontrollably when sleeping. [Answer] Take some kind of bacteria that only clumps together when reaching a critical concentration. Clumping together will disable their ability to enter the hosts cells. [Answer] Another version of the throw up poison might be something your body is able to detect and treat similar to an infection. This compound must be built on proteins that interact similarly like some poison of an animal. In low quantities it just shuts down vital organs and muscles but in higher quantities, your body detects it and produces a fever which destroys the protein (which just happens to have its breakpoint at the human body heat level at fever times) [Answer] Suppose that pills are coated with emetics so that someone who takes an overdose will vomit them up and maybe survive. Suppose that someone injects deadly poison or maybe an overdose of the medicine into the pills of their intended victim. If the target takes the normal amount of pills, the poison or extra medicine will kill him. But if he accidentially takes an overdose, the high level of emetics will cause him to vomit and perhaps vomit enough to survive. So this has taking more of the specially sabotaged pills having less of a probability of death. But it does work only by having the pills contain two or three different drugs with different effects, not one single drug. [Answer] Put things in a bottle that DO not properly mix (eg oil and water bound substances). Make sure whatever is carrying the poison rises to the top with the antidote pooling below... Mind liquid levels and where the spout on the container is! [Answer] I don't know if this qualifies, but a considerably smaller dose of some drugs (I think heroin) could result in lethal withdrawal symptoms, if the user is already addicted to bigger doses. How do you cure drug addiction? With a big dose, but split in a controlled way in a long period. [Answer] [Ketamine](https://en.wikipedia.org/wiki/Ketamine) has very different effects at different doses. At a high dose it is an anesthetic that knocks you out and if that dose is not too high, doesn't kill you. At lower doses it can induce a trance-like state and cause hallucinations. If you put someone in an environment where being knocked out is safe, but wandering around without having full command of your faculties is dangerous (e.g. a mine field, a busy intersection, scaffolding at a construction site, in a trench on a battlefield), a low dose could be deadly, while a high dose is merely incapacitating. [Answer] A real life example: here in Russia stray dogs are a big problem: they kill and maim up to 100 people every year (and those are only registered cases). And our animal control is fake: they do nothing. Country folks get rid of stray dogs by using a drug called "izoniazid", which is almost harmless for humans, but for some reason is deadly for dogs. They say that a correctly calculated doze makes the stray dog just lie down and die, small overdoze would produce agony, but a doze too big will make the dog to throw up, survive, and even become partially immune to poison. So the kind of poison you are asking about definitely exists in real world. But are there drugs that affect a human - I don't know. [Answer] > > **A Little Learning** > > > by Alexander Pope > > > A little learning is a dangerous thing; > > Drink deep, or taste not the Pierian spring: > > There shallow draughts intoxicate the brain, > > And drinking largely sobers us again. > >       ︙ > > >  *(goes on for another 14 lines)* > > > Copied from [Poets’ Graves](https://www.poetsgraves.co.uk/Classic%20Poems/Pope/a_little_learning.htm). Sorry; I couldn’t resist. [Answer] Yes, the question is ridiculous! But it's fun all the same. Really, the answer to your question (and its sub parts) is ["No"](https://www.youtube.com/watch?v=lQG5eR9gNxs). All substances have the potential to be lethal in some way or other given the right combination of nature of substance, amount of substance, size of subject, health of subject, constitution of subject and route of substance administration. **First, we'll look at your actual question, thinking about it logically:** *Can a substance be more lethal in smaller doses?* * A bullet is made of (usually) lead. You can safely hold it in your hand and not die. If it's injected using a standard bullet injecting device (aka a gun), it'll be lethal. A small bullet, properly injected, is no more lethal than a large one. In fact, lethality decreases with ammunition size and power. If you get shot with the smallest size bullet available (a 7 cal pinfire round), you're not going to die as a direct result of being shot. A 95 cal JDJ round. Yeah, that'll be a fatality when properly injected. * A few grammes of bronze make a nice pendant to be safely worn on a necklace. An irate girlfriend could hurl the object at your head, probably in conjunction with a tirade about diamonds and high carat gold, and won't even hurt you. A few tonnes of bronze falling on your head will crush you dead. * A relatively low concentration of gaseous oxygen is nice and refreshing to breathe. Jumping into a pool of highly concentrated & refrigerated liquid oxygen will turn you into a block of ice pretty quick! * Even well known poisons operate the same way. A single molecule of ricin can kill a single cell. A single cell!? It takes a number of castor beans to obtain enough toxin to kill a person. Building from my original answer: * What we can see here is that smaller amounts of substances are far less deadly than larger amounts. * We can also see that any amount beyond this perfectly deadly dosage, again properly administered, is no more deadly than the smaller, adequately deadly dosage. * Finally, that there is a (variable) sweet spot where a substance becomes deadly. Goldilocks all over again. **Conclusion:** every substance has a particular set of circumstances in which it is adequately deadly. Too much of that substance is no more deadly. Too little is not deadly enough. No amount of truth twisting of semantic games will make a substance more deadly at smaller dosages. --- **Next, we'll take a look at the subquestions:** * *In my fantasy world I want a poison, which has an antidote - that antidote being itself.* -- Let's take a look at the [definition of antidote](https://en.wiktionary.org/wiki/antidote): it is some substance that counteracts the effect(s) of another poisonous substance. You're asking for an illogical tautology. If a substance is its own antidote, it can not have had any kind of poisonous effect whereby an antidote would be desired. If a substance has a poisonous effect, it's a poison, not an antidote to the poison. So, +1 for recognising the ridiculousness of the question. I would state, however, that you do leave yourself an out by working within the realms of Fantasy. In Fantasy, there is nothing stopping you from simply declaring any number of poisonous substances, magical or otherwise, to be their own antidotes for *reasons*. * *Here's my theory: the substance is very closely related to something in the human body, like a bacteria or something, but has one tiny difference, which is what makes it lethal, and it kills you pretty fast.* -- This makes sense. There are beings & substances already in the body that work this way. If you become infected with group A streptococcus and develop necrotizing fasciitis, you'll die pretty quickly. There are many bacteria and viruses that can kill relatively quickly. * *If a bunch of this stuff is released into your body, would your body recognize it faster, and since its so similar to your body in the first place, could it be easier to neutralize a larger dose, while a tiny drop would kill you faster?* -- **No.** This is not how the human body works. The immune system works by immune cells recognizing chemical signatures of foreign invaders that differ from the chemical signatures of your own cells. (This is why autoimmune diseases are so nasty -- your immune system recognises your own body as foreign and begins attacking itself.) Once an immune cell recognises an invader, that cell releases a chemical signal that basically says "Oi! There's an invader!" Other immune cells respond by "eating" the invading bacteria, "sequestering" infectious matter or by cells increasing their own resistance to infection. You get responses like swelling, heat and pain as the body tries to lay siege to the local infection. Releasing a whole load of infectious agents will not speed up the recognition process or the chemical response time. In fact, the only effect a *larger quantity of a deadly infectious agent* will have is to swamp the subject's immune system. Sure, it may recognise an infection is present, and will mount a defense, but too much will simply overpower the reaction. **NB:** Also, if the proposed substance is already sufficiently identical in chemical signature to your own tissues, your immune system will not be triggered by it. This is molecular mimicry. The small "dose" of bacterial infection or whatever, will kill your subject adequately. * *Also this is in medieval period before antibiotics.* -- This of course, is a red herring. Even with modern antibiotics, it is still possible to die from sepsis. [Answer] It's not unheard of for a herb or such to have opposite effects when taken in small doses versus large doses. As an anecdotal example (most examples for this sort of thing are probably anecdotal), white mulberries can make me more depressed if I eat a bunch, but if I just eat a few, they make me less depressed than had I not eaten any. Or, it might treat the symptom while you're taking it, but cause the symptom after you stop, or treat it for a period of time and eventually cause it (even if you're still taking it). The same thing that can treat a problem can often cause the same problem. However, making it reliably do the same thing for every person is perhaps the hard part. If it's just one person's physiology, you may be in luck. People often respond differently to stuff that doesn't just intensify the effect based on dosage. So, I think what you're asking is definitely possible. Getting a solid explanation for it and the science behind it might be tougher, though, if you need that. It sounds like maybe an addictive substance with severe withdrawal symptoms may fit your need. The withdrawal symptoms might include death. You might need more of the drug (not a larger amount) to ease off of it over a period. This idea has probably been done before, just for the record. I know similar ones have been done. As an alternative, you could have an essential nutrient. Extremely low doses of it could be fatal, while higher doses could be healthy. Low doses of a substance might cause microbes/parasites to produce a toxin, while a higher dose might kill the parasites (thus evading their toxic reaction). [Answer] Strictly speaking, this is technically not an answer to the letter of the question, but I believe that it addresses the spirit of the question: A syringe (with a hypodermic needle) containing a lethal dose of any poison, pathogen, or whatever — specifically, one that is fatal when injected into the bloodstream. Normally (in the hands of somebody with the technical skill to poke a needle into a blood vessel), this can, of course, be used to kill somebody.  But replace the needle with a piece of pipe with a thickness (diameter) greater than, say, one centimeter (0.4 inches), and it doesn’t work so well.  Sure, depending on how sharp it is, it can be used to cut the victim (like a knife) or cause blunt force trauma (like a club), but it won’t be able to inject a toxin into a blood vessel. ]
[Question] [ Over the course of history humanity rode several kinds of animals to war: horses, camels and elephants being the most common. However, bears are not amongst them. So I was wondering, if they could be properly domesticated and/or trained, would bears be feasible as ridable animals in wartime situations? A bear is a lot more fierce than a horse or dangerous than a camel, but less big of a target than an elephant. This of course also has to take things into consideration like being able to charge, marching speed, their diet, endurance and other such things. [Answer] Yes, but you have to **flesh out your fictional world around it**. Lets assume your world has bear cavalry. That is a - fictional - fact (sic). Lets also assume that this has been so for some centuries. There is a tradition of bear cavalry, and the kinks have already been solved. Your bears are not only domesticated, but also selective bred from wild bear stock for some time now. They are to wild bears what [dogs are to wolves](https://en.wikipedia.org/wiki/Origin_of_the_domestic_dog) now. So, from the answers of my esteemed worldbuilders here, these are the characteristics your bears have been selected for: 1. [Not eating their handlers](https://worldbuilding.stackexchange.com/a/38507/353). 2. [More Stamina on extended sprints](https://worldbuilding.stackexchange.com/a/38509/353). 3. Profile. The war bears would have a better rider-supporting profile. Horses and camels allow the rider's legs to stay relatively stable, and an elephant is rigid enough to allow a howdaw. The bears need to bear a saddle of sorts. Give some thought to the design of this saddle. After all, if it is a bear cavalry, it is assumed the rider fights too, and not just steers the bear. 4. Diet. [fgysin](https://worldbuilding.stackexchange.com/a/38513/353) suggests eating the fallen enemies. I think that if this is done, it should be ingrained into the culture, into a sort of ritualistic proceeding of cleaning up the battlefield. Just allowing the bears to ravage the fallen is bad, since making the bears eat people can teach them how delicious they are. see #1. 5. Diet yet again. Maybe the bear cavalry works in your world because of some rare protein-rich plant that can be grown to feed the bears. This plant might be mild poisonous to humans, but bears can eat them without any issues. [Answer] Not really. Traditionally when an army ran low on supplies, the men would start eating the mounts. When an army with bears starts to run low on supplies, the mounts would start eating the men. This could be really bad for morale. Conventional domesticated herd/pack animals tend to remain passive when hungry, bears not so much. [Answer] The key reason why this is not feasible, is down to endurance - Horses, Elephants and Camelids are native to areas with large plains, and migrations - they are effectively built to last for travel between points - which makes them ideal as beasts of burden. Bears, on the other hand, are built to conserve energy - they are (mostly) native to areas where there is more cover, and even if they are not a hibenatory species, they will go into a torpor to ensure less energy is used when little is available. If you want an animal which would have the intimidation factor of a bear, and the endurance of a horse - I'd suggest an Auroch... [![Auroch](https://i.stack.imgur.com/RcROx.jpg)](https://i.stack.imgur.com/RcROx.jpg) [Answer] As the OP talked about **domesticated** animals I think bear cavalry is feasible overall. I think domesticating bears should work out quite fine: bears belong to the same suborder as wolves/dogs, which were domesticated very successfully (and were also used in war, to a certain extent!). Also bears have been famously displayed in various circus/movies/shows over the ages, showing that even the wild bears out there can be tamed up to a certain degree. Some additional points: ## Endurance As mentioned endurance could be an issue. However, cavalry normally doesn't have an exceptionally high marching speed when compared to infantry, so while your bear cavalry will be slower than horse cavalry, it should easily keep up with infantry regiments and your supply train (which you would need to bring anyway). In combat cavalry is usually used for relatively short charges, which a bear is very capable of. So bottom line: bear cavalry would form a heavy cavalry unit, but you'd still need horses for scouting/skirmishing/surprise ambushes, ... ## Food Food is an issue. Bears eat a lot, and they mostly eat things which you will not find sitting on the roadside by the wagon load (like, for example, grass for feeding horses). So you'd need a good supply train to feed your bears. The good news is that bears are omnivores, so they'll eat pretty much anything... You could probably come up with some sort of special bear [pemmican](https://en.wikipedia.org/wiki/Pemmican) which is durable, compact and can be manufactured in bulk. Also after winning a battle *meat is back on the menu, boys!* ;) ## Tactics I think your bear cavalry will need to come up with some new tactics. While armoring bears and using them to charge into enemy formations should be feasible, I don't think it really uses the bears to their fullest potential. Bears in fights often stand up on their hind quarters, and use their front paws for fighting as well. The problem here is that this won't work so well for the rider... Maybe the bear cavalry would charge into the mêlée, where the rider would jump of and fight side-to-side with his mount. ## Fighting This is really where your bear cavalry will shine. Have you ever seen a bear fight an other bear? Or heard the stories of bears which kept attacking their victims even after being shot multiple times? Bears are very strong and very durable. Horses are natural flight animals, and while they can be trained for combat, the just don't have the same potential. I feel that a domesticated bear trained for combat (and maybe armored?) could be a ferociously efficient fighter. [Answer] I'll give the serious answer, because apparently nobody else wrote it. Bear cavalry is a no-go for about the same reason that we do not raise bears for meat. After all, a bear can be fed with just about anything, and grows quickly, and thus *should* be a good source of food. But it has a big drawback, which is that bears don't tolerate well other bears. You cannot make a herd of bears (however awesome it would be). There is a nice analysis of the conditions of domestication of animals for food production in Jared Diamond's [Guns, Germs and Steel](https://en.wikipedia.org/wiki/Guns,_Germs,_and_Steel), which cites several animals as counter-indicated, for various reasons. Bears are the example of an animal that you cannot put in groups. Of course there are other reasons why bear cavalry would be challenging, as cited in other answers: management of hibernation, difficulty of fitting a saddle on an animal whose weight can triple over the year (they really thin a lot during hibernation), possible low tolerance of the spine to the pressure from a rider... but all of these could probably be overcome. The impossibility to keep bears together is a much bigger problem, which prevents assembling a significant bear cavalry squadron. At best, you could have a couple of scouting bears. (Bears are remarkably good at moving across difficult terrain, so they could make good scouts in mountainous areas.) --- **Edit:** I thought I would add a few extra details. We must make a difference between species. **Polar bears** (*Ursus maritimus*) are mostly carnivorous, and very hard to tame; they see humans as a potential food source (they prefer the taste of seals, but they will still happily munch on human meat). There is currently, to my knowledge, a single [tame polar bear](http://www.dailymail.co.uk/news/article-3229417/Bear-Meet-extraordinary-Canadian-shares-swimming-pool-BED-60-stone-predator.html) in the World; she is used occasionally for movie shots, but even though, they keep her out of fight scenes in case the instinct takes over (I read these details from [this book](http://rads.stackoverflow.com/amzn/click/B007TB5J5E)). **Brown bears** (*Ursus arctos*), including grizzlies, are your best bet for taming. They are huge but relatively gentle. Their diet is also at least 75% plants, and they are really not picky. They are also very tolerant to long periods without food, because that's what they do when hibernating. A grizzly can behead a human with a single paw blow, but it usually won't bother, and does not crave human meat. **Black bears** (*Ursus americanus* for the American species, and *Ursus thibetanus* for the Asian one) are smaller than brown bears, and a bit more irascible, so they would be second choice for cavalry. They might be more useful as enlarged versions of attack dogs; they also have a very keen sense of smell so they could possibly be used for detection rather than charging. **Giant pandas** (*Ailuropoda melanoleuca*) need fresh bamboo shoots. They are totally inept at many things, and it is very puzzling that they have not gone extinct already. The other kinds of bears (spectacled bears, sloth bears, sun bears) are smaller and mostly tree-dwelling; they won't be comfortable on the ground, which makes them unsuitable for military purposes. Of course, there is always the joker of a [bear that knows Kung Fu](https://en.wikipedia.org/wiki/Kung_Fu_Bear). [Answer] A lot of people have mentioned that endurance is a problem in bears, but the truth is that **what evidence there is suggests otherwise**. I won't be answering the question completely here, but I will discuss the endurance of the bears. --- Let's first establish their suitability over short distances. [This source](http://www.nps.gov/parkhistory/online_books/yell/vol14-1-2a.htm) says that grizzlies: > > have considerable endurance, for covering two miles at from 25 to 28 miles per hour proves a stamina that would certainly try the best of horses. > > > [Similar sources](http://www.backpacker.com/skills/ask-a-bear-how-fast-can-you-run/) mention observing grizzlies running at that speed for similar distances without obvious signs of exhaustion. [Compare to horses,](http://www.luckypony.com/articles/horse_long_gallop.htm) which have a similar maximum speed and will be exhausted after running 2-3 miles at it. --- There's a limited amount of information to measure bears' endurance over extended activity, since they hibernate rather than migrate. However, we **do know** that some bears can remain active for long periods of time: [polar bears have been confirmed to swim hundreds of miles for days on end](http://news.nationalgeographic.com/news/2011/07/110720-polar-bears-global-warming-sea-ice-science-environment/). --- So as far as we know, there isn't much of a reason to assume that bears don't have suitable levels of endurance. Assuming that the bears have been bred and domesticated, it's likely that they'll have good stamina. The main issue I can see with a domesticated bear cavalry isn't about how suited they are for the role as a creature, but rather the logistics of keeping them fed. Larger bears typically eat a lot more than horses (where [horses](http://www.humanesociety.org/animals/horses/tips/rules_horse_feeding.html) might eat 20lb of food a day, and smaller [black bears](http://www.wildernessclassroom.com/wilderness-library/black-bear/) up to 18lb, but [brown bears](http://animals.nationalgeographic.com/animals/mammals/brown-bear/) and [grizzly bears](http://www.animalfactguide.com/animal-facts/grizzly-bear/) might eat 90lb a day. However, this might be related to building up reserves for hibernation; if this is controlled or bred out of them, they may eat smaller amounts and not hibernate. Bears may also need a more varied diet than horses, complicating things further. [Answer] I'm going to avoid some of the issues which have already been covered by some of the excellent answers upthread, and focus on the key issue: you want bear *cavalry*. Bears are not well shaped for riding, have a strange "rolling" gate when running (which would make riding a real challenge) and tend to rear up to fight with claws and teeth, which negates the true benefit of shock cavalry, the momentum of the charge. Having your mounts pull up and rear to fight makes most cavalry weapons like lances, spears and sabres far less effective than they are with cavalry mounted on horses. You would be effectively reduced to the sorts of weapons that ancient cavalry used (javelins or bows). The Ancient Greeks had a form of light infantry trained to grasp the manes of the cavalry horses and run alongside them into battle (you see this trick in the movie "Alexander", when they suddenly emerge from the clouds of dust raised by the Companion Cavalry and attack the Persian Cavalry sent to stop the Companions), so bears might be accompanied by this sort of infantry soldier rather than being ridden like a horse. So a bear charge will see bears racing into the enemy lines accompanied by light infantry wielding swords. If the emery line has been breached by missile fire (archery etc) or a Cavalry charge, then a well timed rush by bears and their infantry will create havoc and open the breach further for exploitation. [Answer] The bear would be very fast and much more powerful than the horses or camels (having claws and very sharp teeth) so the bears could be taught to fight along with their rider . Of course , if you ever have to face an elephant in combat , your bear and you are gone ( see [this](https://www.quora.com/Who-would-win-in-a-fight-between-a-bear-and-an-elephant) ). But otherwise , the bear would be a feasible choice for combat . To feed them , you would need fish or meat which is costlier than grass/hay which you could use to feed horses . This means the bear would be more expensive to keep. This would mean that bear cavalry would be less preferred than horses / camels . Bears are quite fast , being able to outrun a racehorse for short distances , but cannot endure at such speeds for very long (source <http://www.bearsmart.com/about-bears/general-characteristics/> ) .Hope I helped ! EDIT - Another problem is - **BEARS HIBERNATE!** . So , if war breaks out in winter time , when your bear cavalry is hibernating , better have backup ! This probably means bears can only be troops in summer and definitely not your primary cavalry . [Answer] # Bear Saddles The other answers here are excellent and cover a lot of the potential pros and cons of bear cavalry, I just want to add a suggestion for a saddle that may help alleviate some of the issues you may encounter. ## First, what won't work: A horse style saddle: A horse saddle is fine while the horse is horizontal, but when a horse rears up on its hind legs, riders tend to fall off. Since one of the best advantage of a bear is that it can rear up and fight with its bite and front paws, you want a saddle that can hold a rider during rearing. Additionally, bears are too wide to have the legs easily splayed to either side of the body the way you can with horses. An elephant-style saddle: An elephant saddle is great because it is basically a whole platform for a person to sit/stand on, and it very stable. Unfortuantely bears just aren't big enough for that kind of saddle to be practical. Alternatively you can sit on the neck of an elephant, but that puts you in a bad position on a bear (if they could even comfortably hold you). ## Here's my suggestion: A saddle where the rider has his legs to either side with his knees forward and his feet back (the legs would make a "W" shape). His feet would fit into a stirrup that holds it securely both while the bear is horizontal and while it is vertical. This would look like the bottom part of a horse stirrup, but turned 90 degrees and attached securely to the saddle. The knees would have some sort of padded spot to rest on while in the horizontal position to bear a lot of the rider's weight. There would also be a good handle of some sort in front of the rider where a horse saddle's pommel would be, but with a horizontal grip to hold onto. The saddle would wrap around the middle of the bear as well as around the shoulders so that it is secure in both orientations. ## Advantages of this design: * When the bear is charging the rider can hold onto the grip securely and stay low on the saddle (the leg position encourages the rider to say low and secure). * When the bear is reared up, the rider can stand up in the saddle as well (now with legs extended and holding onto the handle). * In either position the rider can use a one-handed weapon to fight against the opponent's bears and riders. ## Disadvantages of this design: * It would likely be uncomfortable to those not used to it. The leg position is totally doable for flexible people, but would take a lot of time to adjust to if you weren't very flexible. It is possible the discomfort would be too great, it is hard to know without trying it (**Note:** this is *not* recommended before you actually tame/domesticate the bears). * Mounting may be difficult, but I suspect that you could add a footstep on the side of the saddle to aid in getting up and down. If anyone who is more artistically inclined would like to mock up a drawing of this kind of saddle please do and send me a link, I would love to include it [Answer] You might find this video from CGP Grey spot on: <https://www.youtube.com/watch?v=wOmjnioNulo> It expands on why horses got domesticated but not... zebras. The TL;DW version is that, well, horses form docile herds with a lead horse, whereas zebras are stubborn and all over the place. Catch the lead horse and the herd is basically yours. Rinse and repeat for cattle, sheep, etc. Hence we domesticated horses but not zebras, cows but now buffalos, etc. Now try to recollect when you saw a docile herd of bears with a lead bear steering it. :-) There's more to the video but that alone rules bears out. (And no, I do not think it's realistic. But hey, it's World Building...) [Answer] In terms of feasibility and desirability, it might be more preferable to breed 'up' a species of animals which is already domesticated. Like dogs. Mastiffs, wolfhounds, and great danes were all bred for use in battle. While they're not large enough to ride, it's conceivable that over successive generations they could be bred up to be larger still. Consider the Pomeranian, a small dog breed sometimes smaller than the chihuahua. A century or so ago, they were bred down from larger Wolfspitz work dogs. A breed fostered over several centuries for size, and already starting from a larger dog, might very well be able to be large enough to ride. For fiction, bears would suffice, I suppose. But they do not have a skeleton which is ideal for riding, and their lope is quite uneven. Most bears, moreover, are probably not large enough to ride as mounts. Consider: a typical riding horse weighs about 1200lb, and can only carry about 250lb. The largest of male bears only get up to that weight, whereas they're typically closer to half to a third of that. You're not carrying a 200lb man with 50lb of gear on a 400lb bear. [Answer] Some points on bears in warfare, as well as an alternative to bears which would likely be more favorable logistics wise. Oh, and apologies for the lengthy answer. To start with, how well would a bear work out in war? To start off with, you could armor a bear. A bear that was kept for war would logically be well fed as it grew, and so would be a good size, note, that means it would be about 1.5 metres at the shoulder on all fours, and 3 metres at the shoulder while on its hind legs. I took a look at a picture of a rearing grizzly, assumed a height of 3 metres at its shoulders, and an average armor thickness of 2.25mm (the thickness of plate armour was 1.5 - 3 mm, thicker in the areas more likely to be hit, thinner in other areas). If you gave a bear of this size armour to cover it's entire torso, the top three quarters of its arms, the top three quarters of its legs, and a kind of collar protruding from the breast plate to protect the throat, you would use just shy of 90kg of steel. A bear of this size can lift up to 500kg, so this is not a problem. An unarmoured bear is already difficult to injure, and it is important to note that weapons don't cut steel. When facing an opponent armoured in plate, you aim for week points, areas of the armour which need to be flexible, in this case, the armpits, which can be protected with pauldrons or besagews, the elbows, and the backs of the knee's. This would be difficult to do, your average polearm tips out at a length of 1.8 metres, but only half of that extends out in front of your hands, and a medieval man had an arm of about 75cm. This gives a theoretical range of about 1.65 metres, but you don't use the tip of a weapon, and you don't fight with your arms fully extended. All things considered, the average soldier armed with a polearm, can probably fight at a distance of about 125cm. Assuming a shoulder height of 1.5 metres for the grizzly bear, therefore arms 1.5 metres long, which can easily deliver enough force to kill you while fully extended, this becomes a problem for the enemy. So maybe the other guys think this through and decide to use a bow and arrow, after all, it is a big target, problem is, arrows don't pierce steel all that well, and even if it did make it through the armour, it now has to make it through a thick layer of fur, a thick layer of tough bear skin, and a thick layer of fat, before it can do any real damage. As far as I can see, this only really leaves three alternatives, another bear, an elephant, or fire. Elephants are even more logistically difficult than bears, and not all that common in war, when it comes to other bears, it would likely come down to the bigger, or better armoured bear. As for fire, there is a reason it wasn't used all that commonly in medieval open warfare, when you have a massive tract of land, packed tight with men, trampled grass, and beasts of war, a fire can be difficult to control, and could just as easily end up killing your own men as it could the enemy. As for logistics, I have a couple of things I would like to point out. First off, as "Thomas Pornin" pointed out in an earlier post, grizzly bears eat 75% plant matter, berries, roots and whatnot. Second of all, even if a bear cost as much to feed as ten men, it could well still be worth it, as they could easily be worth more than ten men on the battlefield, especially when used at the right times. And third of all, even if you were not willing to feed fallen men of the other side to your bears, which could be for any number of reasons, you could still feed the enemies fallen beats of burden. The horses they ride, and the cattle and donkeys used to drag their supply wagons. My final point on logistics, is that if you were to send the bears ahead for scouting, some time could be dedicated to allowing the bear to forage, or even hunt, as this would lighten the load on your supplies. When it comes to tactics, there are several purposes a bear could fulfill. As scouts, bears might suprise you with how quietly they could make their way through the woods. They would also easily cover ground most people may have trouble with, and would be able to hold their own if they encountered an enemy scout. Obviously you would still need to have at least one person with them, to relay gathered information and whatnot. On the battleground, while they would be powerful weapons, what would truly make them valuable, would be the fact that your enemy knows they need to be killed, and this will take a large number of soldiers to accomplish. And while twenty enemy men reach your front line concentrated on killing the bear, they are left relatively open to a counter attack by your more traditional forces. Allowing you to use the bear as a sort of anvil, and your men as the hammer. As a front line unit, they would likely be invaluable to holding the line, as they would be near impossible to push back, even by a cavalry charge, as they are heavier and stronger than even traditional heavy cavalry, and likely wouldn't have much of an issue breaking a horses neck. They could also serve as a kind of heavy cavalry, accompanied by handlers rather than ridden. The impact they had on the front line of the enemy would be considerable, and quite probibly measured by the tens of enemies fallen per bear. During any kind of siege, they can take on an additional purpose, properly equipped they could be turned into a kind of living battering ram, generating more force on impact than a team of men. Additionally, they are, despite their size, capable climbers, and could scale low walls erected by the enemy. However their is an alternative you could use for your fictional world, which could quite probibly fix any logistics problem you encounter. Giant ground sloths. These varied in size depending on the species, from the size of a large ape, to the size of a small Elephant, and we're built much like bears. This solution providers a couple of pros and cons, listed below. They where herbivores, meaning they where easy to feed, they could simply browse on trees as they went. They had a network of bones under their considerable hide, which served a perfective purpose, and have been compared to chainmail. Well normally placid, and thus easily controlled along the journey, unlike horses, they are built for fight, not flight. This means that during battle they would instinctively swipe at the guys pointing the pointy things at them. However, they still would not have made the best mounts, as, due on part to their large claws, were probably knuckle walkers. They were also likely considerably slower than a bear of comparable size, they simply weren't built for speed. As for actually getting to the point where you could take one of these animals into battle, well, a ground sloth likely lived in small groups and so may be easier to tame and domesticate, but as suggested by other posters, you could have the bears in your world be social creatures, it's really up to you. [Answer] One thing not addressed by previous answers, but worth considering, is that bears are very intelligent animals. In fact, both horses and bears are very intelligent (possibly [as or moreso](http://news.discovery.com/animals/horses-communication-dogs.htm) than dogs): This is what makes them easy to train. But it also begs the question: **what incentive does the bear have?** A horse forms a very close bond with its rider, in part because it is a social animal and its social dominance heirarchy enables it to interact with dominant members of the herd (humans, especially its rider; with dogs, this is sometimes seen as a parental relationship, since wolves operate in family pack units and dogs are widely considered to be infantilized wolves). Horses' social dominance heirarchy and pack/herd mentality allows it to respond to threats (charging, rearing up) as if it were challenging a competitor or protecting the herd, differently than it would respond alone in the wild (running away in terror). **In short, horses feel protected.** They also become docile when subjected to domination, even mistreatment (sadly). That is why they tolerate being ridden, long term. Now consider the bear: even in a scouting expedition (for which the bear is ideally suited), what incentive does the bear have to suffer the harsh conditions of war alongside its master? **The bear does not need its master for protection** such as from carnivores, which is the key social contract between men and horses; or rather (unlike the dog) it is not familiar enough with human technology to understand that being with its master will protect it from the ranged weapons of rival humans; in the absence of ranged weapons, a bear is capable of fighting and scouting on its own: the rider is merely dead weight. The bear would respect its master but not be led around by him, certainly not into battle. Brown are one of the few species that don't immediately respect men as the apex predator and aren't dependent on them for protection from other predators; when the human thinks "we're in trouble", in the (apocryphal) words of Tonto from *The Lone Ranger*, *"What do you mean **'we'**, human?"* [Answer] Only to supplement Thomas [Pornin's](https://worldbuilding.stackexchange.com/a/38582/44475) and [Ber's](https://worldbuilding.stackexchange.com/a/38822/44475) answers: Domestication is not the same thing as taming. All domesticated species have a social hierarchy, where a human replaces the alpha animal of the herd. Therefore, domestication requires social animals, i.e., wolves, horses, cows, sheep, goats, etc. They all have a degree of hierarchy in their social structures. Taming is when you reinforce an animal to do something. You can reinforce a cat to litter in a box but you cannot reinforce it to follow you unquestioningly. So, even if you achieve selective breeding to weed out non-conforming genes, there is no initiative for the bear to follow you. Therefore, the best you can get out of a bear is a huge cat. Can you make a cat attack someone? Sure, I have witnessed cats attacking on command. However, battlefield is much more than attacking on command. Fighting in formation is the most important thing on the battlefield. Well trained horses and camels actually bite and kick enemy soldiers and animals. Well trained elephants swing their tusks to break spear walls. These things are possible only with domestication. A similar comparison can be made between gladiators and legionaries. Gladiators were trained to fight single combats with certain rules, while legionaries were trained to fight in formation. While most gladiators were good enough to defeat any legionary in single combat, use of gladiators in medieval warfare has failed miserably each time. If you are looking for legendary animal fighters, orcas might offer better results. Some large dinosaurs are suggested to be hunting in packs, but this doesn't necessarily mean they have tight social hierarchies. Nonetheless, they are more promising than bears. [Answer] I'm surprised that, out of all the wonderful answers given so far, nobody mentioned a technological solution. **Cyborg Bears** could be guided, and even controlled by their brain implants. Perhaps their anatomy could even be modified to make them easier to ride or to give them enhanced senses, weapon mounts, etc. Of course, one might wonder why such a technologically advanced society might use cyborg bear cavalry instead of regular vehicles... * Technology developed along different lines than in our world. Just because we invented things in a certain pattern doesn't mean everyone will. * The society in question may have lost the ability to build war vehicles and other similar tech. * They may not have the ability to fuel vehicles, while still having power sources for computers (biochemically powered implants). Perhaps [von Neumann](https://en.wikipedia.org/wiki/Self-replicating_machine) (self replicating) technology is at the heart of their computing tech. * The society may have a cultural or religious taboo against vehicles. * Environmental factors may make using living mounts more practical than vehicles. Perhaps they have wheeled vehicles, but nothing that can handle rough terrain. Perhaps some form of radiation prevents the use of their regular transportation technology. * The Bear Cavalry serves a ceremonial purpose more than a practical one. **Of course, there's always magic to modify and control the bears as well.** [Answer] Animals such as bears are a large competitor for prey animals and require a lot of meat to keep happy. You don't want your ride to decide that you will make a nice snack. Keeping a large bear well fed is very expensive, that is why so many are in shelters or have to be put down, they cost too much to keep, and that is as a pet with an easy life, not a hard working war mount. Bears are also usually solitary, partly because it is easier to feed fewer mouths when you get bigger. Wolves are pack animals and a human can replace a wolf as the leader. This will not with bears, there is no such thing as a bear pack (thank god). Most animals we ride are herd animals, they are easy to feed, usually grass and other vegetation (often stuff we can't digest well) so there is no competition for food and they are generally not going to try and kill each other. [Answer] Wild animals, even if trained, can easily get out control under war conditions. This is especially problematic if the animal is strong and dangerous enough. Dogs (but not wolves) were probably the only carnivores used in a war to fight on one side (not to "attack all"). Factors that made this possible probably are * The dog behavior is a result of the long selection towards making the dog easy to control by the master. * Dogs are not especially dangerous to the human army and can be killed it they get out of control. ]
[Question] [ In a world where time travel is possible, but has not been invented *yet*, would travelers from the future come back to prove it exists? Surely, they would bring that technology back in time to let the people of the past use it? I have four theoretical explanations so far, **can anyone explain them in more detail, or provide other possibilities?** 1. The people decided to ban backwards time travel to prevent mass panic in the past, or to prevent possible paradoxes. 2. The people in the future went back in time to an alternate past. (Similar to the [Many worlds interpretation](https://en.wikipedia.org/wiki/Many-worlds_interpretation) but with time travel). 3. The people come back in time to give the people in the past new technology, they then jump forward in time to see how humanity has progressed using this. The result is that the future they return to is different to the one they left. 4. They cannot go back in time because it has already happened, and therefore they can only go forward in time. [Answer] In all probability, we, 21st century barbarians, will not be very well loved by our 23rd century descendants. Non-historians of that age will probably group us together with the generations of the late 20th century, and refer to us collectively in their high-school level history courses. We are the generations who baked the earth and poisoned the seas. We wiped out thousands of animal species and held the world hostage for almost a century under the threat of nuclear or biological annihilation. Our insanity almost brought about human extinction and led to the Second Dark Ages, from which they are only just recovering. "You want to give our time travel technology to those mad men? ARE YOU NUTS? Leave them in the past where their damage has already been done. We don't need them coming up here to further screw up our present!" [Answer] In the film [Primer](https://en.wikipedia.org/wiki/Primer_(film)), there was a time travel machine that could only jump as far back as when it was first turned on. This puts a practical limit to how far back you can jump to the point where time travel was invented in the first place. [Answer] Because the earth orbits the sun at 30km a second, the solar system is moving at 20km a second and the galaxy is moving at 230km a second! Any time travel will result in the people being dumped out into the void of space... Maybe we need to set up some beacons to guide people to the earth through time and we can only set these up now... [Answer] Here's another option that is often forgotten: Time travel might need an exit system available at the destination. Since we don't have an exit system in our time, time travellers cannot visit us. For example, time travel might be done through a wormhole whose two ends are shifted in time relative to each other, so if you enter one opening, you come back through the other opening, say, one year earlier. Going back several years would work by passing it several times, and going back is done by passing it the opposite way. Then of course you only can travel to times after that wormhole has been established. **Edit:** Here's a second thought that occurred to me: What if the time machine doesn't travel with you? Think of the Star Trek transporter: If people are beamed to the surface of a planet, the transporter doesn't travel with them; it remains on the ship. If they couldn't ask the people on the ship to beam them up again (say, if the transporter could only beam them away), and there were no other means to fetch them back (like shuttles), they would be stranded on the planet. In a similar way, a time traveller that comes to our time would be stranded in our time; we simply don't have time machines to send him back into his time, and probably don't have the ability to build one in his life time even if they'd bring the plans with them, nor the energy required to operate it. Which would be a strong disincentive for anyone to visit us, unless he actually wants to live in our time — but in the latter case, he'll probably not tell us that he's a time traveller, as that will be counter productive for his plans. [Answer] Two potential solutions: 1. They are able to travel to the past, but are unable to alter it. This includes showing off their time machines or other future technology or knowledge, or anything else that might remotely change the progression of events. This is the [Novikov self-consistency principle](https://en.wikipedia.org/wiki/Novikov_self-consistency_principle). 2. They have come back and told us, but their influence is retroactively expunged by *other* time-travellers charged with maintaining a consistent past. [Answer] Ever noticed how people in time travel stories mess everything up? And then somehow by the skin of their teeth manage to put everything back to rights? Things probably don't actually work like that. About half of the time the calvary doesn't arrive in time, the answer to the riddle fails to pop into the hero's head, the match doesn't light, the green wire blows up the bomb. Time travel gives people infinite chances to mess everything up. Each chance to destroy the world plays out instantly as time travel is invented -- time travel takes all the possible spins of Russian Roulette and plays them at once. The moment you invent time travel you fork a possible universe off, do your messy business, destroy everything and the only possible universe that still exists is the one where you didn't. In any universes where time travel is invented the world is destroyed instantly. The fact that our world still exists can be taken as proof that we're on one of the few possible timelines where time travel doesn't, will not or cannot exist. [Answer] [@chrisj](https://worldbuilding.stackexchange.com/a/51218/760) hit on the grand problem of time travel: you have to travel in time *and space*. I'd love to expand on all the ways this ties time travel to space travel. The surface of the Earth is rotating at 0 to 465 m/s depending on your latitude. Fortunately momentum will be conserved (it must otherwise that would imply there is an absolute rest state for the universe) so when you jump you will also be traveling at that speed. However you'll be somewhere else. Even jumping 1 second back will place you 465 meters away... possibly in a brick wall. This is the least of your problems, because this assumes the Earth is standing still. The Earth is moving around the Sun at about 30,000 m/s. Now if you jump back in time 1 second you'll be 30km away from where you started, probably either 30km inside the Earth or 30km in the air. Not good, but with some careful calculations you could construct a plane or spaceship or something? And if you want to jump back years you just make sure to jump when the Earth is in the same spot in its orbit. I have bad news. The Solar System is rotating around the center of the galaxy at 220,000 m/s taking the Earth with it. Now if you jump back one second you'll be somewhere between 240 km and 200 km away from where you jumped, depending on which way the Earth was moving in its orbit. That's bad, but a spaceship can still fix that, right? Let's say time travel is invented in 2216 and they want to come back to 2016 to tell us all about it! In that time the Solar System will have moved... ``` 220km/s x 60 s/m x 60 m/h x 24 h/d x 365.25 d/y x 200 years ``` 1,388,534,400,000 km or 1.4 trillion km or 1.4 x 10^12 km or 0.147 light years. That's ok, your time machine is also a spaceship! You can fly back to the Earth. And you're in front of the Earth, so it will catch up to you! Well, I have some more bad news. You came out in front of the 2016 Earth, yes, but you are continuing to move at 220 km/s around the center of the galaxy in the same direction as the 2016 Earth (the difference in angle is so slight it does not matter for rough calculations). The Earth will never catch up to you. You're going to have to fly all 0.147 ly back to the Earth. What if you went even further back in time to give yourself more time to travel back to the Earth... now you pop out even further away from the Earth and have to travel even further to get back to it... Basically your time machine also needs to be an interstellar space ship. Maybe time travelers have visited us. [![Exhibit A: A time traveler visiting Earth.](https://i.stack.imgur.com/YK1ly.jpg)](https://i.stack.imgur.com/YK1ly.jpg) P.S. There is a version of time travel where this is not a problem. Instead of jumping from one point in time to another, you instead speed up time. Now you are passing through every point in time. This means you are subject to the forces of gravity and held in place on the Earth. [H.G. Wells' **The Time Machine**](https://en.wikipedia.org/wiki/The_Time_Machine) and [the time machine in Futurama](https://www.youtube.com/watch?v=YNC06iKu28g) seem to work this way. [Answer] ## Just because they can doesn't mean they will. Most people have phones; why do they not call people in other continents to tell them about their phone? Many people have cars, why don't they drive to places that do not have cars? Despite the simplicity of this argument, it gives you the answers; 1. They don't care about people from the past. 2. They do not want to give people from the past time travel 3. They are not allowed to give people time travel technology. [Answer] **Option 1: Time travel is a one-time deal** Let's suppose time travel allows you meaningfully alter the past. By jumping back in time you're erasing the future you came from, leading to the good old fashioned grandfather paradox. Let's just sidestep that - You're physically in the past, so let's just assume you're now part of the past. Kill Hitler, save Lenin and Franz Ferdinand, do whatever you want. You've now altered the time-stream such that the invention of time travel most likely happens at a different moment, if it happens at all. If the new inventors of time travel jump back the same thing will happen, either erasing you if they jumped earlier or erasing their own discovery if they jumped in after you. If one of these jumps alters the timeline so that time travel isn't discovered, then it'll stay that way forever. If anyone from anytime can travel to any point in the past, then there's effectively an infinite chance this has happened. In the same way that people say it's statistically certain we live in a simulation, I say it's statistically certain we live in a universe were time-travel was permanently un-invented. **Option 2: Time travel is for forensics and archaeology** Maybe time travel doesn't even send you back in time - Maybe it just lets you see the past exactly as it was, like a kind of reverse Minority Report. I don't really have much to say about this one - It avoids all the problems of causality because it's non-interactive, but aside from perfect reconstruction of the past it's pretty dull. Great for documentaries, bad for trying to hunt dinosaurs. [Answer] I think there's something subtle missing from the "how do you account for Earth's motion" explanation: which reference frame does your time machine use? Sure, the Earth is rotating, but that's relative to the Earth's center. It's also orbiting the sun, but that's relative to the sun. That's also orbiting the galactic center, but that's relative to the galaxy. The galaxy is moving through space relative to other galaxies or relative to the CMB. So which reference frame does your time machine move relative to? How does it establish that reference frame and track it through time? Reference frames are sort of arbitrary, you need to tie them to something physical. And maybe that's how you resolve the problem. Maybe your time machine isn't a vehicle, it's a portal and a portal needs two ends. Only the two ends aren't separated by space, they're separated by time (or both). So why aren't time travelers coming in from the future? Because we haven't built the time machine yet. [Answer] We are the ALPHA-TIMELINE. Just as space expands, the dimension of time expands as well, the process of which we perceive as the passing of time. We are at the very edge of time, any new moment that happens hasn't existed before it happened. History is the coordinates of time we leave behind. As the progression of time only happens because of the "pressure" that the past exerts on time, everytime you travel backwards in time, you collapse the present; once you travel back, the time you have travelled too is the new edge of time (so, no travelling back to the future). [For added weirdness: Maybe the collapse only happens locally. When you travel back, you only reset those parts that you have an effect on, causing this part of spacetime to be out of synch with the rest of the universe]. **There are no travelers from the future, because the future has yet to happen.** [Answer] Time travel to the past requires both a sending device in the future and a receiving device in the past. Without both in place, no backwards time travel is possible. It could be that no stable wormhole will form, or attempting travel without a receiver will always result in the traveler being atomized. No matter how far technology advances, nothing is able to overcome the need for a receiving device. Thus the earliest time period to which a time traveler can travel will be the first successful invention of the time machine, which, of course, hasn't happened yet. This means that whoever invents the first working receiver will be inundated by travelers from innumerable points in the future who've come to witness the birth of time travel, and/or the earliest possible era they can travel to. So, if you invent a time machine, make sure you have a lot of receivers built before switching **any** of them on. Or don't ever tell anyone or record anywhere that you made one. --- A couple alternate explanations: * Only a few attempts at backwards time travel were *ever* attempted throughout all of (future) history. Some were successful, but for one reason or another they always seemed like catastrophic failures from the sender's perspective. No one ever returned or sent back data, and no one managed to leave a clear indicator to the future that they had succeeded. So time travel was determined to be impossible, and every few thousand years when some nut-job tried again, the same basic result occurred, keeping time travel in the "impossible" category. * Each trip back in time actually creates an alternate universe, with the original universe continuing to exist. From the original universe's perspective, time travel is unsuccessful and is instead a way of destroying matter and energy. We are in the original universe, so no time travelers have *arrived* in our universe because they actually arrive in an alternate one. The alternate universe's history is identical to ours until the moment a time traveler arrives in it, and which point the events begin to diverge. [Answer] There are various theories for this, the most common being > > Backward time travel creates a parallel timeline where it happened, the prime timeline remaining untouched. > > > This prevents paradoxes, it also means that the primary timeline can never have examples of backward time travel. It also means that you can never go home, never undo the damage you've done, only get slowly further and further away from the world you knew. Another popular option being > > Time travel is only possible as far back as the first implementation of the technology. > > > The best known of these being under the wormhole theory. Which allows you to create wormholes for time travel but you can't go back to a point before you created the first wormhole. There's also the classic > > It happens all the time, but my mate says the government covers it up. > > > I think this needs no further comment. But there's also the more important: > > How would you know? > > > What has been has always been from your point of view. [Answer] Because you can't interact with time, in the general sense. Time travel isn't like going to Disneyland and stading in line for all the cool rides, arguing with the guy that cut in front of you, or sweating future sweat all over the past. It's more like going to an animated wax museum and watching the same script play out over and over and over again - you can change perspective, pay attention to this or that, but you can't change any of it. Future time travelers use the technology to study the past for what it was and not how it is portrayed by biased writers. In this way, future time travelers are able to help future soceities learn from the past's mistakes and truly make the future a better place. [Answer] The one remotely plausible mechanism for time travel is through "frame dragging" with a massive rotating object. The purpose built device is known as a "T machine" after Frank Tippler, who first proposed it, but it may be possible to have a similar effect using a rapidly rotating neutron star or black hole. Essentially what happens is the rotating object bends space-time in such a fashion that light cones are "tipped" and point to "elsewhen", outside of the 45 degree boundary defined by the speed of light. The illustration demonstrates how this is done: [![enter image description here](https://i.stack.imgur.com/lYYLZ.png)](https://i.stack.imgur.com/lYYLZ.png) [![enter image description here](https://i.stack.imgur.com/V5eI8.jpg)](https://i.stack.imgur.com/V5eI8.jpg) There are a number of different assumptions you can make (and since no one has a working T machine to test it on, many of these ideas are equally plausible). Number one: you cannot go any farther back in time than the creation of the T machine in the first place. Since we are talking about an artificially maintained cylinder of neutronium rotating at nearly the speed of light, this isn't a project that is going to be carried out anytime in the near future (or at least *our* near future). Number two: moving into the past or future creates a new "timeline", and this timeline simply sees you start spiralling around the T machine and vanishing, never to return. Number three: Since travelling in time is essentially travelling to "elsewhen", you have left our universe. This is related to number two, since there is no guarantee that the tipped light cones will actually be pointing back to your starting point. Even in the unlikely event that your light cone is pointed back to our universe, it might not be pointed back to our region of space, or to our current time. Popping back in existence in our universe one billion years in the future or one billion light years away has some obvious problems for the time traveller. Finally, most of these ideas are based on the assumption that you can equally access the T machine after travelling through to "otherwhen". Passing through the field of tipped light cones and emerging in an empty universe where there is no corresponding T machine is going to be a huge problem. [Answer] An option that has not been mentioned in the main answers (only found in the last one by colmde, when I thought it would not have been raised) is that such time travel discovered in the far distant future may not allow to travel back in time to where we are now. Probably not due to physics laws if it is able to travel back in time, but due to economics. So, traveling back a week, is affordable to almost anyone. Traveling back a month, would be a severe hit to your economy but generally doable. Traveling back some years is something only governments or big corporations can afford. Traveling back hundreds of years, you would need the energy of dozens of suns to power your travel machine, thus it is "impossible" even though time travel is allowed and routinely performed in this universe. Actually, it is uncommon that it would cost the same to travel back 1 day than 100 years (but I don't know the details of the time machine that is discovered in that distant future). Moreover, the power needed to travel back probably isn't linear to the time traveled but likely quadratical. [Answer] I think it was Larry Niven that came up with the solution: If altering the past is possible then the means to do so will never be discovered. The thing is, if time travel is possible someday someone will tamper with the past. Somebody else will tamper with the past and so on. The only stable state is the one in which the time machine is never discovered. Thus any observer in a universe with a time machine gets reset out of existence and thus all observers see no time machine. Note that this does not preclude what I call time roads--something where the time travel technology doesn't travel in time and thus you can only reach a point while it already existed. Such a device can't be reset out of existence. (Example, Robert L. Forward, *Timemaster*--time travel was attained by relatavistically altering the relative age of the ends of a wormhole. Take one end to the stars and bring it back, hop through and you move a fixed distance through time.) [Answer] After inventing this technology, they tested it by going back to a point that is still in our future, activated some paradoxes, and **wiped themselves out before they could send the information, people, etc. farther back.** Alternatively, they did figure out how to send information back in time, but they used quantum entanglement and other such effects to do it, so **we have to wait until we've built the receivers** for those messages before we notice. Analogously, we can send a radio signal deep into a forest, but if there's nobody in there with an appropriately constructed receiver, they won't notice the information being sent to them. [Answer] Time travel is powerful. So powerful that you don't want those other guys to have access to it. So you use time travel to get rid of them. (unless, of course, they get rid of you first) The timeline can only sustain, at most, one time traveler, and he's not sharing. (credit for the basic idea goes to Erfworld fanon, regarding the magic school of retconjuration) [Answer] They already did. And THIS happened. **We are already living** in the end product of time traveler meddling. It didn't go so well, so they stopped doing it. Mostly. As for why it isn't widely known, please - be my guest. Start telling people. [Answer] 1.) **It will not be humans as we know them now that develop time travel.** From the Sagan Series: [The Frontier is Everywhere](https://www.youtube.com/watch?v=oY59wZdCDo0): > > It will not be we who reach Alpha Centauri and the other nearby stars. > It will be a species very like us, but with more of our strengths and > fewer of our weaknesses, more confident, farseeing, capable, and > prudent. > > > I think the same concept applies to time travel. We're quickly approaching [the singularity](https://en.wikipedia.org/wiki/Technological_singularity) and as such, people will either become exceedingly enlightened and abandon much of what once made them such petty creatures or they will [cease to exist](http://www-rohan.sdsu.edu/faculty/vinge/misc/singularity.html). The "humans" (more likely to be cyborgs) of this future will understand the long-reaching effects of their actions and won't want to interfere with the past if it might cause unforeseeable consequences to the future. 2.) **Humans of the future have already been wiped out** It can't be said that humans have passed the [Great Filter](https://en.wikipedia.org/wiki/Great_Filter) yet. We're still living in tumultuous times. We still might wipe ourselves out. No humans in the future means no one to come visit us. 3.) **Alternate time lines** As others have mentioned, it may be the case that alternate timelines exist or branch when someone tries to change something in the past. This prevents time paradoxes. 4.) **We haven't made any receiving devices yet** As others have mentioned, it might be the case that time travel requires receiving devices that we haven't developed yet. It's easy to calculate where the Earth will be 200 years from now, so that won't be a problem, but no device to travel to might be. 5.) **There might be infinite timelines for time travelers to go to and we're one of the infinite that don't get traveled to** Maybe time travelers can travel to any of an infinite number of time lines. the chances of one landing on our time line is infinitesimal. There are trillions of years for them to travel through and trillions of universes, but maybe only a few time travelers so far. The odds of them showing up during the last 5,000 years of our recorded history out of the trillions of years that our timeline will exist are very slim. [Answer] There was a short story by Larry Niven named "Rotating Cylinders and the Possibility of Global Causality Violation", inspired by a mathematics/physics paper of the same name by J. Frank Tipler. In the story, archaeologists investigating the artifacts of an extinct alien civilization have discovered documents describing the theory of these time machines, along with at least one incomplete prototype. One of the characters theorizes that the universe itself somehow acts to prevent the activation of any such devices, in order to prevent any violation of its physical laws. In the instance of the extinct alien race being investigated, I believe that the sun of their star system had gone nova before they could complete the device. [Answer] I am going to address the second option on your list, [Many Worlds](https://en.wikipedia.org/wiki/Many-worlds_interpretation), in more detail. In my opinion, it is the only physically-sound explanation for how time travel could exist while no effects from it would be visible. That said, Many Worlds is itself a bit of physics-woo, so make of it what you will. The basic concept of Many Worlds is that for every possible outcome of an event, the universe splits, and both (or however many outcomes are possible) occur. It is closely related to the concept of [Quantum Immortality](https://en.wikipedia.org/wiki/Quantum_suicide_and_immortality), which comes out of the application of Many Worlds to [Schrodinger's Cat](https://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_cat). In that thought experiment, a cat is left in an undermined state inside a box, either alive or dead. The primary issue is that, if the cat is in an undetermined state, what does the cat perceive before the box is opened? Many Worlds suggests the cat experiences both continued life and death; Quantum Immortality is the suggestion the cat would merely experience continued life, thus becoming immortal. This is related to time travel in that it suggests every *possible* event, no matter how incredibly unlikely, occurs. Considering phenomena such as [zero point energy](https://en.wikipedia.org/wiki/Zero-point_energy), where probability is the main factor preventing absurd random occurrences (and entropy, the addressing of which is beyond this answer), the word "possible" can effectively be removed from that statement: **every** event occurs. Now, imagine some time traveler returns from 2222 to now. Let's presume the time machine comes with them, for the sake of discussion. What is the probability that a time machine and a time traveler appears in your front yard in the next hour? It's insanely - nearly impossibly - unlikely. But following certain conditions and making certain assumptions, it is *possible* for that to happen. Meaning in some universe, it *must* happen. Now, there is an issue with this, and it is where the cat returns. From your point of view, the probability of that occurrence is so vanishingly small it is easy to ignore. People and time machines do not just materialize out of thin air. But the probability from the *time traveler's point of view* is substantially higher. If the trip does not fail and he is not killed in the process, his only option is to appear in your front yard. It's worth pointing out this would suggest probability can be "localized" to a given person. Again, that's well beyond the point I am making. Because of the difference in the probability of outcomes between you and the time traveler, we end up in a case where the time traveler is effectively routed to a specific branch of time where he and his machine popped into being. You and I never experience this because it is so insanely unlikely that just in a pure probabilistic sense, we end up in some other branch of time. However, at least some number of you in other branches of time *do* see the time traveler. There's just *many more* of you that do not experience a time traveler appearing in their yard. It is also worth pointing out this would mean temporal paradoxes are actually impossible to form, since upon going back in time, the time traveler would be entirely decoupled from their own origins. They effectively just spontaneously came into existence remembering "their" future. --- So to summarize all that physics-woo, the Many Worlds interpretation applied to time travel would suggest it is merely very unlikely we end up in the same universe as any given time traveler. It's not impossible, but so insignificantly unlikely we can go about our lives with it never actually happening. [Answer] Anyone arriving from 'not now' (either direction) would, by so arriving, automatically create an alternate timeline to 'contain' them. So there may in fact be alternate histories in which people are aware of time travelers. But we are all stuck in the original timeline and never get to see anyone arrive. *[On a side note: nearly every depiction of time travel is impossible because anything which travels, by arriving or leaving, automatically violates conservation of energy. The only depiction which stands a chance of avoiding this is the 'Terminator' kind in which pieces of space-time - presumably of the same energy content (though how is this enforced?) - are exchanged between source and destination]* [Answer] It's very simple. Time Travel only goes one way. It's called cryogenics and right now it generally has a 100% fatality rate. The problem with this question is that it makes a faulty assumption. It assumes time exists. A better approach is to ask oneself, "What is time?" Simply put, time is perception. It's possible to perceive time at an incredible rate. Don't believe me? You're living proof. To something like an idea or concept that stands outside of the universe's perception, the all of reality might happen in an instance. It isn't slow, it just perceives events at a different perception. Another aspect is causality. Humans evolved in a way to create assumptions. We assume a beginning and an end. This instinctively creates a range. Here's another fundamental flaw. The universe isn't a dog or cat. It's timeless and infinite. It's not old, because that would require that it didn't exist at some point. Scientist busy themselves trying desperately to prove a beginning. This is because the other option is infinitely terrifying. The universe is in a way, its own cosmic horror. It defies reason. It is the absents of reason. In short, it's hell. Time works along the same misconception. If time existed, it would mean that at every point that the universe exists, there is a backup. The problem with this, is that there isn't a place to store something like that. Infinite isn't a number. It's a concept. It's something that isn't big. It just is. Causality is a human construct. If we didn't have memories or our memories were a jumble, time wouldn't be a concept at all. Instead of thinking of time as something to be traveled, it's more accurate to realize that there is just motion. We build our own time. The universe won't be bent to anything's will. Even something like an elevated idea can't undo an event. When a lightbulb breaks, you can only replace it. So in short, time doesn't exist. A lot of people are making a whole lot of money creating a comforting lie. The sooner the elites stop looking for comfort the sooner we can get back to fixing real issues. P.S. I'm sorry if this seems like a downer. I'm not trying to insult anyone. If this is pure science fiction speculation, then I have missed the point entirely and I apologize. [Answer] Actually, the very first time traveller started out now, in 2016, going back some twenty years. When he got there, they asked him who was running for president in 2016. When he tried to tell them it was Hillary Clinton versus Donald Trump, they put him in a quiet room where he couldn't do anybody any harm. [Answer] # It's too hard to find parking Time travel requires you to specify a time **and a location**. As you would guess, specifying an exact location is quite important. If you appear 100 meters in the air, you die. If you appear 2 meters underground, you die. if you appear on a wall, you die. Would you risk it? A time machine can't be expected to know what it means to land "in someone's back yard", it needs exact coordinates, with the axis starting from, i don't know, probably the center of the universe or something. As soon as we start recording exact coordinates of safe landing spaces on earth, people from the future will appear. [![enter image description here](https://i.stack.imgur.com/aS1iB.jpg)](https://i.stack.imgur.com/aS1iB.jpg) "I'll just go around the century again, I can't find a spot" [Answer] Ok lets first break apart your questions: **Question 1**: > > ...would travelers from the future come back to prove it exists? > > > **Answer 1**: Why would they bother, what possible motivation would they have for this. They know it is possible and exists they wouldn't need to prove it to the past. **Question 2**: > > Surely, they would bring that technology back in time to let the > people of the past use it? > > > **Answer 2**: See Answer 1 Now lets look at your theoretical explanations for why this might not occur: > > I have four theoretical explanations so far, can anyone explain them > in more detail, or provide other possibilities? > > > **Theory 1**: > > The people decided to ban backwards time travel... > > > **Response:** People ban lots of things and still people do those things, so most likely some people would still do that thing. **Theory 2**: > > The people in the future went back in time to an alternate past. > > > **Responses**: Personally I've always viewed alternate pasts as a hack trope of time travel plots. I comprehend alternate futures, but the past seems rather fixed from the POV of whatever *when* you are. Besides if this were the case then it doesn't particularly matter. **Theory 3**: > > The people come back in time ... then jump forward in time... they > return to is different to the one they left. > > > **Response**: This is basically the classic many worlds/alternate timelines trope. Again if their present changes, it is still our relative future so no big deal from our POV. **Theory 4**: > > They cannot go back in time ...therefore they can only go forward in > time. > > > **Response**: So basically.... they are us. Traveling forward in time and never back. But have you considered that perhaps they have and do. Maybe they have been here maybe they have marched up the steps of the white house and declared that they are from the future and presented us with a time machine. Maybe they've created countless paradoxes. Here is the funny thing about time travel. We do it all the time without thinking about it, albeit in one direction. If we could turn around and go "the other way" we would un-perceive things going in reverse. Funny thing about this is that in-fact there is no reason to believe that we are in fact going in the "right" direction we may live in a back-wards universe with crazy things happing like, gravity pulling things together, light coming out of stars and and people being "born". Now...if we could jump back or forward in time but then continue forward in time at our normal temporal pace.. ah this would be what we think of as time travel, with that concept, there are basically four primary possibilities I can see. * Time travel is only possible in one direction. Period. (borring) * Time travel is possible *(at this point we make an assumption that if time travel is possible it is impossible to avoid all paradoxes)* + There is some mechanism outside of the known universe to prevent paradoxes from forming. + The universe is always in a state of paradox but because we are in the paradox we are unaware of it + Any universe in which time travel is possible is a universe that will ultimately destroy itself before it exists. Personally I like this last option... unfortunately this also means that the first option is also true. So the point of all this is that. In a universe where time travel is possible there is no reason to believe that we would know it when we saw it even if it were sitting right in front of us. [Answer] Most of the ways we have hypothesized to time travel require that the ability to time travel exist in the time you are trying to get back to. In other words, if Time travel is possible, because we haven't invented it yet, they can't get back to us. It's really kinda simple ^.^ [Answer] There's a law that says it's illegal to travel into the past. Governments fear that even the smallest time travel may alter the present and cause unforeseeable consequences. The time travel technology is in the hands of so few people that it's possible to enforce the law. ]
[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- This question does not appear to be about **worldbuilding**, within the scope defined in the [help center](https://worldbuilding.stackexchange.com/help). Closed 8 years ago. [Improve this question](/posts/20860/edit) Often your Towel is something which is very useful to carry around with you, especially in The Hitchhiker’s Guide to the Galaxy where you are taught to upgrade your Towel by, say, reinforcing the stitches in your Towel, or soaking a corner of it with nutritious substances so that you can suck it in an emergency. In fact a rather [large list](http://www.h2g2.com/entry/A667253) has been constructed of uses for your Towel. So now I come to my question, I want to learn Towel chi: The Art of the Towel, and for this I need to upgrade my Towel for military purposes, specifically military Towel combat. So I was wondering how I should best upgrade my Towel for these purposes? And please, when you answer, give the mighty Towel its honour by giving it a capital 'T'. [Answer] Actually, careful analysis will show that Towels are **already** perfectly optimized for military use. Any permanent modification to the Towel, while improving it in a single dimension, will reduce its flexibility. For example, if you improve the Towel's bludgeoning capability, you reduce the protection it can give you from chemical attacks or its use as an improvised picnic blanket (remember that armies march on their stomachs). Therefore, you should not try to upgrade the Towel. Instead you should upgrade your mind. Unpredictability is the key to warfare, and sticking to a single tactic will quickly lead to defeat. Consider that if you always get your Towel wet and then try to use it as a garrote, your opponents will simply start carrying hair dryers. Instead you should develop several disparate tactics and use your Towel as a randomizer. When your enemy appears, simply throw it in the air and watch how it lands. Then kill them based on the appropriate randomized tactic. I'll give you a sample chart here: * Folded in two - strangulation * Kind of a wobbly-line type thingy - whip the Towel at them like you're in a gym shower until they run screaming to the principal. * Flat - pull out your tea set and challenge them to a duel of wits. * Perfectly folded, as if by your mother - they will bow down to you and become your follower. * Ends up going really, really high - pull out your gun and shoot them while they stare in awe at your Towel tossing abilities. * Kind of vaguely like a sheep's head if you squint at it - you have successfully predicted their death in the form of The Grim. Your opponent will realize they are doomed, walk away and be hit by a bus. * Hovers in midair before you - you both bow down and become the Towel's followers. This is, of course, quite a short list - you'll need to develop your own Towel-tossing chart and tactics. But in the end you'll find yourself undefeatable. [Answer] Take a large rock (a half-brick is traditional). Place it in the centre of the Towel. Gather the Towel up around the rock and twist to form a long flexible form with a heavy weight at one end. To upgrade further, tie this all together using string, or for an extra bad-ass-upgrade, use gaffer tape. Swing resulting weapon over the head and strike targets with the weighted end. In extreme circumstances can even be launched as a ranged weapon. [Answer] Assuming you have access to unlimited advanced material science: 1. Weave your Towel from a special polymer/compound/nanomaterial which - while water-absorbant in normal circumstances - can also be triggered - by termperature, or electricity, or radiowave, or other triggers - **to assume different shapes and mechanical properties**, with multitude of military uses: * Straighten out into extremely thin, very hard, wire/lance. You now have a stabbing or throwing weapon, better than any dagger or lance or javelin due to small cross-section (though for throwing aerodynamics and momentum transfer are an area of further research needed). * Become an extremely strong yet flexible string. Can be used for close quarters combat as any string/rope/line (choking, tying, tripping, lassoing, making traps, etc...); as well as a basis for building other weapons (heavy object at the end of a rope, bolos, bow strings etc....). + BTW, a whole bow can be made by combining several flavors of this weave: a flexible string for a bow string; a bendable spring-type form for actual bow; and the lance-wire form for an arrow. * Become an elastic string, making it possible to use in constructing slingshots (in case you run into antagonistic green pigs) * Become a material with mechanic properties of tree branch, for use as a bow. * Become a Kevlar-like shield. 2. **Communication**. There is no modern military without communication. * Special weave can be turned into an antenna * in-clothing circuitry can actually contain a whole communication device * White Towel surface can be used as a projection screen * White Towel can be used to signal surrender {insert French jokes here} * White Towel can be used as a writing surface; and with proper material engineering, as an etch-a-sketch. * With even better technology, a Towel can serve as a display. 3. Amateurs study tactics. Professionals study **logistics**. * You can use the Towel as a carrying bag. * If the Towel is made from proper material (see #1), it can be turned into a sled. * In survival situation, fluffed out pieces of Towel can serve as a very good kindling. * If the Towel is made out of watertight material on one side (which admittedly makes it a pain to dry out when used as an actual Towel), use it as shelter from the elements. Raicoat, windbreaker, etc... * If you are in a need of an infantry slog, you never know when you need good socks type solution. A Towel can be used to make socks, or similar things. * For that matter, you can use the Towel to make mittens/gloves, or simply to shield your hands from hot/cold/dangerous stuff (e.g., lifting a hot kettle off a fire when cooking in the field) 4. Other **MacGuyvering** solutions using Towel as a piece of cloth. * You can use a Towel as a poor man's parachute * You can make it into a rope, to escape high place. * A properly colored Towel can be used for camouflage. White for s arctic/tundra. If you're lucky, your Towel is chromatophoric and can change colors, or even adapt camo patterns. * A Towel can not only be a kindling for a fire as per above, but a workable **fuse**. 5. A way to **clandestinely carry dangerous compounds**. Someone else already mentioned poison. But that's just the start of it. * Wet the Towel in a solution of highly radioactive material. Then you can either use it to give someone radiation poisoning; or use it to transport radioactive material (the latter seems useless, without radiation detectors a Towel isn't really needed) * Wet the Towel in a compound that in and out of itself isn't dangerous. But, a second Towel is wetted in a material that - while not dangerous - when combined with material in a second Towel - produces a powerful explosive. 6. Or hell, you have access to nanomaterial. Just have your Towel be made out of **[Gray Goo](https://en.wikipedia.org/wiki/Grey_goo)**! At needed moment, signal them to stop pretending to be a Towel, and start Eating Everything! [Answer] The Hitchhiker's Guide provides some handy hints as well: Wrap the Towel over your *own* head. If you cannot see the Ravenous Bugblatter Beast, it cannot see you either..... Pan Galactic Gargle Blasters[™](https://trademarks.justia.com/865/82/pan-galactic-gargle-86582726.html) make amazing weapons. Drape the Towel over your arm to disguise yourself as a waiter (most alien species have never *seen* Earth people before, so you should be safe) and serve the drink to your unsuspecting victim. After downing the drink, the victim should pass out and then wake up with a feeling of having had their brain smashed out with a slice of lemon wrapped around a large gold brick. Few other weapons or devices can compete with that. Once the victim has been immobilized by the drink, you are then free to do whatever you need to do (although activating an Infinite Improbability Drive and escaping is usually the best bet). [Answer] It may be best to weave into your Towel a Sombody Else's Problem field generator, dye it bright pink, and wear it as your only form of clothing, preferably in the least appropriate manner possible. You can then power this off of the single torch battery for most if not all of your life, thus your Towel has become a cloaking device. While not explicitly weaponizing the Towel, it should be noted, you will be completely invisible to all but the most astute, and can simply stick them with a shiv in their heart, brain, gelatinous nerve center, power core, and/or most other vital organs without the least bit of interference. [Answer] Find a source of liquid, preferably something poisonous. Place most of the Towel in the liquid, allowing it to soak it up. Carefully - use gloves if necessary - tie the Towel up, like intertwining threads on a rope. The resultant rope-like weapon will hurt any opponent quite a lot, as it is now somewhat heavy. I believe this was referred to in the comic strip *Calvin and Hobbes* as a "rat tail". For close-quarters combat, feel free to use this wet Towel-rope to trip up the opponent or strangle them. You can also use the poison to your advantage. [Answer] A wet Towel can be wrapped about your face in the event of a chemical attack. Although not as effective as a gas mask, the wet Towel is at least a better air filter than a dry Towel would be. [Answer] * Put it in a big jar of petrol, now you have a huge ass Molotov cocktail. * Put if flat on the ground, when someone walks on it, give a quick tug and they'll fall to the ground [Answer] The method we used in my youth was as follows: Place the towel on the ground in front of you long edge at the bottom. Fold the two upper corners down toward the center bottom edge creating a triangle. Roll the towel roughly downward parallel to one of the upper sides of the triangle. This forms what is commonly known as a 'rat tail'. To make it even more formidable, just dip the end in a bit of water. To use it simply grasp by the fat end and use it like a bull whip. It can rend flesh to bloody welts in an instant and if practiced with restraint can be used to cause bikini clad girls to give you a fairly pleasing demonstration of inertia as they gingerly hop about to avoid it's snapping tip. [Answer] Get a **White Towel**. Wave it at your enemies if you are under attack. For reasons unknown, this will cause your enemies to adopt the "Goliath Posture". Their mistaken sense of superiority affords you limitless opportunity for cunning and artifice. **TL;DR** Your Towel is best understood as a *psychological* weapon. [Answer] Upgrade today to a Peirson's Puppeteer Towel, the absolute pinnacle of Known Space Towel technology! The circuitry of a [Slaver Statis Field](https://en.wikipedia.org/wiki/Known_Space#Stasis_Fields) is sewn into the fabric, allowing your Towel to be frozen at the atomic level in a timeless state, immutable, un-malleable and indestructable. From Bullet-proof Shield to Baseball Bat, the Puppeteer Towel is the irreplacable for every Guide Agent, everywhere! Available in both urban, forest and desert camouflage colors. [Answer] I'm suprized no one has brought up **[Towelie](https://en.wikipedia.org/wiki/Towelie)** ![enter image description here](https://i.stack.imgur.com/FkOR9.jpg) A *militarised* towel from the South Park series. > > **Military Leader:** You did very well bring the towel back here, boys. Let me ask you something... What was it that those people at Tynacorp told you? That the "big, bad Military" wanted to turn Towelie into a weapon of mass destruction? Now let me tell you the REAL story... > > > we've been making our own smart-towels, but only because we HAD to. > You see, when we started spying on Tynacorp, we discovered a certain > terrifying secret... > > > Tynacorp was using these towels to take over the world! > > > Don't you see what towels like these are capable of?? You get out of > the shower and dry yourself off... But then, the towel makes you drier > and keeps on making you more dry... Can you imagine it? What it would > be like to be way, way too dry? I'll tell you something: you don't > want to know, and I don't know. > > > [Answer] If you want to improve the Towel, so that it does not get bloodstains on it from war in the first place, I would suggest nano-coating it. That would however not be good for it's fluid-soaking capabilities, which are one of the core-capabilities of a Towel. But maybe bloodstains are a feature on a Towel, not a bug? Then you could wave your blood-stained towel at your fiend, and they would be so scared, they would bow down to you and hail you as their master. But as this would only work with fresh blood (nobody is scared by dried blood, right?), you would need to remove them between uses. How to remove blood from your Towel after it has been used for war: **1.** Soak your Towel in cold water. The water should be as cold as possible in the circumstances, but not frozen. This should be done as soon as you can. Fresher blood yields better results (is it not always so?). **2.** If it is accessible to you, add a bit of detergent to the mix. If your Towel is white, bleach can be added too. **3.** Let it soak, preferably over night, but no more than 48 hours (lest your Towel might start disintegrating or rotting). **4.** Wash your Towel at a normal cycle in a washing machine or hand wash it vigorously if none such is at your disposal. **5.** Hang your Towel up to dry properly. As a woman, I can testify this is the most efficient way to remove blood from a Towel. [Answer] The BudK catalog, mostly containing knives and Zombie Apocalypse supplies, had a cheap "space blanket" for sale. A blanket is just a large towel, right? This is thin aluminized material that is folded and compressed into a very tiny package. Even without cutting down, you can fit it in your pocket, smaller than your wallet! As indicated in the accepted answer, optimizing the Towel for some purpose compromises it for others. This is optimized for "keeping warm" as a thermal layer, and high de-optimized for drying off or being cushioning. Even so, it has unique uses not shared by my regular Towel: it can reflect light like a mirror! It's actually water and air tight, rather than porous. It might be useful in fashioning a still for drinking water, both for concentrating sunlight *and* for providing a surface for condensation *and* making a water-tight container *and* keeping the wind off the apparatus. The accepted answer makes me realize that the real point is being very *general*. Just like duck tape and paracord, it has a variety of uses. In the Towel in particular this relies on *mediocre* properties, having some blend of A and B which are each accessible, as opposed to being much better at A while not having B. I recall Microfiber cloth towels for sale, and one of the reviews explained how they are great for keeping on a sailboat because they are remarkably absorbant yet more compact when dry, so good for limited storage. So it is with the Towel: you want it easily stowed and thus light and compact. So use materials not known at the time H2G2 was written, using *microfiber* napping to be both suber absorbant for water and able to handle hydrophobic (oily) materials as well. Make the weave out of super strong monofilliment. Have it so if you cut off a strip it won't make the rest of the Towel unravel, but you *can* unweave the strip to yield a long strong cord (and a handfull of loose felt). The loose felt could be used as fire kindling. The strips torn make good bandages, so make the fluff be antimicrobial as well. --- But that's all 2010 technology. Just as we have stuff at Walmart that was impossible in 1985, what will the future — or advanced technology from aliens — bring? Ever hear of [Programmable Matter](http://www.wilmccarthy.com/HackingMatterMultimediaEdition.pdf)? [Wil](http://www.wilmccarthy.com/hm.htm) uses this in several of his SF novels, and has a real-world patent on the quantum well technology. > > The Flick of a switch: A wall becomes a window becomes a hologram generator. Any chair becomes a hypercomputer, any rooftop a power or waste treatment plant. > Imagine being able to program matter itself—to change it, with the click of a cursor, from hard to soft, from paper to stone, from fluorescent to super-reflective to invisible. > > > Or a humble Towel. Now *there* is a mil-spec towel for you! It normally maintains the form of a primitive cloth towel, with random daily changes to its color and print pattern. If used for any purpose, its intelligence automatically modifies its form and properties to be better at that task, while stealthily trying to remain "just a towel" to outward appearances. In more extreme needs, it can morph into any material desired. Folded up into a compact form, it will *be* your 21st-century phone/PDA. Unfold for a big screen, window, sheet metal, or the softest silk. Wrap it around yourself and it becomes a full space suit with life support capble of adapting to any extreme environment. ]
[Question] [ How many humans are needed in order to sustain and grow a steady population in a habitable area? Assume resources are adequate and the environment is favorable. To further refine this question, let's assume this is an early spacefaring technology scenario, such as putting a colony on a neighboring planet (same system) with earth-like conditions with a technology level either current or near-future. Assume the population has a mix of professions suitable for the new environment (resource gatherers, physicians, etc.). [Answer] This is quite dependent on technological/medical knowledge. For example, it has been [calculated at 160 for space exploration](http://www.newscientist.com/article/dn1936-magic-number-for-space-pioneers-calculated.html#.VBiC_XtDLwo), provided the explorers return home after 20 generations. This of course assumes pretty good medical availability and actually fairly low risks to individuals. The resultant reduction in genetic variability has been analyzed as not being very detrimental. Certainly it *could* but not guaranteed to and even small infusions of genetic material would majorly reduce negatives. Also starting out with high genetic variability will help reduce those risks. A good example of a relatively genetically non-variable population is Ashkenazi jews; a [recent study](http://www.iflscience.com/health-and-medicine/dna-traces-jewish-history) has suggested that in semi-recent history (25-30 generations) their total population was around 350 individuals; yes there are some genetic defects that are common but there is no generalized unhealthiness (or genetic unthriftiness), and some genetic defects are rare because they weren't very present in that initial population group. I would say that 160 is a fairly good minimum for a colony; yes- less than that may survive but any minor disaster has an unpleasantly high chance of wiping out the colony. The lower the technology/medical treatment availability the higher the population would need to be to provide a 'buffer' for injuries. [Answer] 15 individuals, 8 males and 7 females are certainly enough to create a sustainable population, capable of growth without any out-breeding, albeit with some genetic diseases due to in-breeding. The reason we know this is because of a small island on the Atlantic Ocean, Tristan da Cunha, which has a robust, growing population of 243 (2021), and have been inhabited for about 200 years. All people living on the island can derive themselves from 15 individuals, 8 males and 7 females. The population is a textbook example taught in genetics courses. [Tristan da Cunha - Demographics (Wikipedia)](https://en.wikipedia.org/wiki/Tristan_da_Cunha#Demographics) [Answer] The answer by @Nick Wilde is very good, but the quoted number of 160 (the source actually claims 80 is possible with social engineering) refers to what is minimally required to sustain a stable population for 10 generations. This could be relevant if your planet would be very far away, however if you look at the distance between Earth and Mars, it just takes about a year to move from one planet to the next. As such, the population that you would need to fit inside the spaceship could be reduced significantly, as you can simply let the population grow on arrival. It is hard to quantify this effect, but as 80 already can be sufficient for a stable population, I dare say: ### Starting out a growing population can be done with less than 80 people, if chosen carefully. That being said, the main concern seems to be genetic diversity. Sources vary a bit on the subject, but it appears that with the current technology sperm can be frozen for at least 1 generation. So, let's do a quick calculation: Suppose we need to reach a population with 80 unique genetic sets to go past the tipping point. Let's do a quick calculation on how this can be achieved if fertile women are able to give birth to 4 children on average and have taken a bunch of frozen sperm samples with them: * Generation 0: 10 (fertile) women and 10 frozen samples * Generation 1: 20 women and 20 men and 80 frozen samples * Generation 2: 40 women and 40 men From this point on the women of generation 2 could continue to expand the population with the men of generation 1 and 2. It is true that a little bit of bad luck could already mess up the system, but being on the safe side it seems like: ### A spaceship with 20 women and a freezer full of sperm is likely enough to start a growing population. [Answer] This is known as the Minimum Viable Population, and many computer models and studies based on various circumstances and species have been run. For Humans, including the desire to ward of genetic defects due to inbreeding the median MVP reported is 4,169 individuals. You can read up more on this on the [wiki article here](http://en.wikipedia.org/wiki/Minimum_viable_population). [Answer] *I'm going to ignore genetic diversity because the necessary population to sustain a technological environment will always demand enough people to satisfy that requirement.* Assumptions: * Maintenance of the basic technology that brought them to the new planet. Not necessarily rocketry... but vehicles, automation, manufacturing, etc. In other words, I'm assuming we didn't spend trillions of dollars to move a population to a new world so they could wear skins and fish with spears sharpened by broken rocks. * Self-sustaining colony. All the mining, farming, logging, maintenance, manufacturing, etc. must exist within the colony. * The colonization process brought a single set of all the tools needed to get through, say, a year, but after that the colonists must provide for themselves 100%. * Automation is commensurate with what's available in 2017. Automation changes these numbers RADICALLY, but the OP doesn't really tell us anything other than it's a intrasystem space-faring society in the near future. **Family Size** Your [average family in the United States](https://www.statista.com/statistics/183648/average-size-of-households-in-the-us/) is 2.53 people. I'm not even going to speculate on what 0.53 people looks like. Worse, even if you round it to 3, that's two parents and one child, which is a decreasing population. You need 4 to break even and 4.1 (better known as 5) to grow. Let's favor 5. Out of that 5 people let's assume you have two adults, one sub-adult, and two children. That's 2 laborers, one laborer/secondary education, and 2 dependents requiring child care and education. > > **Your biggest problem is children.** They can't be ignored. If you arrive with no children and expect to start making babies you need adults for child care immediately and both education and medical by age 5-6. Therefore, you really must account for children at the outset or your fooling yourself. You could squeeze my final number by minimizing children based on age distribution so that you're getting replacement adults "just in time," but that's much more complicated. > > > **Farming** From [here](https://recipes.howstuffworks.com/how-many-farmer-feed.htm) we learn that on average one farmer can feed 155 people. This assumes an established farm in 2010. If we assume the farmer has a family and that he can draw on a "basic labor pool" to get him up and running, then our farmer +4 (family) can feed 150 people or 5:155. farming = 5T/155 where T = Total population (keep this in mind). **Logging** I thought I could assume if we can get this group to another planet then we can construct with plastic and metal and therefore there is no need for logging. However, it's likely you need crates, paper, rubber, composting, and who knows what other non-foodstuff organics. I can't find statistics for how many people are involved in this. Let's use the farming number and assume one family can serve an additional 150 people with non-food organics. So, another 5:155. Logging = 5T/155 **Mining** This is one of the more problematic issues. Different materials appear in different locations on a planet. This means our colony has many labor centers, all requiring administration, law enforcement, etc. I'm going to define mining as "anything we take from the ground that we can't eat," so it includes petrochemicals. According to [here](https://mineralseducationcoalition.org/mining-minerals-information/mining-mineral-statistics/) the average citizen of the U.S. needs 40,000 pounds (20 tons) annually of materials of over 15 types. (I'm being optimistic about the "and other" categories and counting them as one each.) Mining requires blasting/digging/drilling, hauling, and processing. I have friends who work the hard-rock mines in northern Idaho, and even with automation, they have hundreds of laborers. Granted, it's production mining rather than subsistence colony mining, but still.... Let's assume you need 2 blast/dig/drill, 1 haul, 2 processing for 5 people (25 with families). I must assume a massive ratio or this simply doesn't make sense, so let's assume 25:3000 per item on average. Remember, that's 2 blasters/diggers/drillers producing their share of 60,000 tons per day. It can be done. I must be done, because... Total: 825:3000 (see my problem?) mining = 825T/3000 > > We need to sub-calculate the number of labor centers for later calculations. That would be T/150 + T/150 + T/2175 = 30T/2175. > > > **Transportation** We need to get things from one place (e.g., farm or mining location) to someplace else (at least another farm or minining location). If we only assume two drivers + families (trucks or trains... pray we're not dealing with trains...) per labor center. trans = 10(30T/2175) **Maintenance** Keeping the equipment running is a very difficult variable to define. Let's assume two full-time mechanics per labor center. maint = 10(30T/2175) **Education** The [United States has](http://www.nationmaster.com/country-info/stats/Education/Primary-education%2C-teachers-per-1000) 5.49 teachers per thousand students. We have some austerity going on, so 5:1000. [Secondary eduction](http://www.nationmaster.com/country-info/stats/Education/Secondary-education/Teachers/Per-capita) is 5.5, but this is more important, so 6:1000. Plus families. education = 55T/1000. **Medical** Keeping all these people alive will be a problem. Keeping them healthy an even bigger one. You've gotta love the [CIA](https://www.cia.gov/library/publications/the-world-factbook/fields/2226.html), who suggest 2.55 physicians per 1,000 people in the U.S. I doubt this includes specialists and it certainly doesn't account for multiple labor centers. So, 2:1000 MDs and 1 MD per 3 labor centers and 5:1000 specialists. Plus families. medical = 2T/1000 + 10T/2175 + 5T/1000 ≅ 25T/2175 + families = 125T/2175 **Administration** This includes everything from paper-pushing bureaucrats to police, firemen, code enforcement, phone answerers, etc. My right-big-toe tells me we need 3 per labor center + families. admin = 3(30T/2175) = 90T/2175 + families = 450T/2175 **Manufacturing** According to [here](http://www.nam.org/Newsroom/Top-20-Facts-About-Manufacturing/), manufacturing jobs are 8.5% of the U.S. workforce. Let's assume that's only one parent in a family (like everything else). manufacturing = (0.085)T/5 + family = 0.085T I'm going to assume this number includes drivers, administrators, maintenance, etc. It's going to be a bit low because of the compounding affect of unassigned workers, but all that would happen is fewer unassigned workers increased by the same amount of additional manufacturing jobs. So the total population estimate should remain "accurate." (*ahem*). **Entertainment** I'm going to ignore entertainment of any and all kinds. Colonists should plan on bringing kazoos. **Unassigned Workers** I've intentionally not tried to compound the spouses or sub-adults into the workforce. This is because there will be jobs ranging from street sweeper to technical assistant that I'm not even going to try to estimate. All those jobs must draw from the unassigned labor force (and sub-adults, as necessary). > > **What am I missing?** I'm missing retail outlets, which would presume some kind of town or village. For an initial colony, central distribution or coordinated transportation could solve this until the community begins to grow. *I'm sure I'm overlooking/ignoring a lot of other things, but this is a long enough post.* > > > --- **That's a mess... how do you calculate the minimum population?** * We're going to iterate through the equation. * We'll use T=1 to find our starting point and ignore the divisors so we have one of each primary laborer plus their family, which means our "initial population" is 2,070. We know this isn't right because we don't have enough raw goods to feed/supply all those people. * We want to assume that we never increase a number unless the population has actually exceeded the amount required for the increase. No fractional doctors, please, otherwise all the fractions add up to wholes that run out of control. However, this means people are a bit overworked... but that might be expected on a new colony. * With the exception of our raw materials. We must have enough farmers, loggers, and miners. So we'll round those numbers rather than keeping them at the floor. **Total minimum population: 2,260** * Children: 904 * Sub-adults: 452 * Unassigned Workers: 452 * Farmers: 14 * Loggers: 14 * Miners: 123 * Transport: 61 * Maintenance: 61 * Education: 24 * Medical: 25 * Administration: 92 * Manufacturing: 38 ***Is this realistic? To be honest, in real life you probably need 10X this number of people... but I can't prove it without spending 10X the time to analyze the situation.*** --- **My Program (PHP)** `$a = 100; $t = 1; $ifar = 5; $ilog = 5; $imin = 825; $itra = 300; $imai = 300; $iedu = 55; $imed = 125; $iadm = 450; $iman = 5; $t = $ifar + $ilog + $imin + $itra + $imai + $iedu + $imed + $iadm + $iman; $count_check = 0; $count_max = 1000; while($a > 0.01){ $far = 5 * round($t/155); $log = 5 * round($t/155); $min = 5 * round(165*$t/3000); $tra = 5 * floor(60*$t/2175); $mai = 5 * floor(60*$t/2175); $edu = 5 * floor(11*$t/1000); $med = 5 * floor(25*$t/2175); $adm = 5 * floor(90*$t/2175); $man = 5 * floor(0.085*$t/5); $pop = $far + $log + $min + $tra + $mai + $edu + $med + $adm + $man; $a = abs(($pop - $t)/$t); $t = $pop; if($count_check >= $count_max){echo "\n\nFAILED TO CONVERGE!\n\n"; exit;} $count_check++; } echo "\n\n"; echo "Total Population:\t".$pop."\n"; $children = 2*$pop/5; echo "Children:\t\t".$children."\n"; $subad = $pop/5; echo "Sub-adults:\t\t".$subad."\n"; $spouses = $subad; echo "Unassigned Workers:\t".$spouses."\n"; $far /= 5; echo "Farmers:\t\t".$far."\n"; $log /= 5; echo "Loggers:\t\t".$log."\n"; $min /= 5; echo "Miners:\t\t\t".$min."\n"; $tra /= 5; echo "Transport:\t\t".$tra."\n"; $mai /= 5; echo "Maintenance:\t\t".$mai."\n"; $edu /= 5; echo "Education:\t\t".$edu."\n"; $med /= 5; echo "Medical:\t\t".$med."\n"; $adm /= 5; echo "Administration:\t\t".$adm."\n"; $man /= 5; echo "Manufacturing:\t\t".$man."\n"; echo "\n";` [Answer] As well as the biological, social and genetic diversity issues of maintaining a viable population you also need to consider maintaining technology. Clearly a small colony on another planet is going to very very reliant on technology to survive. Just for a start it is not difficult to imagine a situation where a new strain of a disease could cut a catastrophic swath through a small colony and even without anything catastrophic day to day illness and injury will be a big strain without adequate medical facilities. Equally you will need engineers and technicians to keep the basic infrastructure going. Automation can probably help with this to some extent but it would certainly seem risky not to have a reasonable depth of expertise in how it all works, especially as the generations go by and you want to expand and refurbish the facilities. So if we hand-wave the technology of actually getting there and assume a level of technology similar to current with reasonably foreseeable developments on an earth-like planet then we can start to get at least some idea. **Medical** In the developed world there are hundreds of medical specialities and we probably have to accept that a small colony won't have the same breadth and depth of expertise and facilities. Here a good model might be a military field hospital as they are designed to be portable and versatile and are well equipped to deal with both traumatic injuries and primary healthcare as well as epidemics and natural disasters which seem reasonable priorities for a colony. So you might have : * Surgeons * Anesthetists * Surgical nurses * General practitioners * Dentists * Pharmacists * Ward nurses * Intensive care nurses * Primary care nurses * Paramedics * Specialist cleaning and logistics staff For a long duration colony you would probably also want lab technicians and medical researchers although these may be part of the science department. Obviously you would want personnel with a broad a range of expertise and experience as possible. Similarly if you intend to use working animals and livestock you will want a few vets to look after them. **Government and administration** Clearly this depends on how you want the colony to be run but with a military type model you would have something like a regimental headquarters with a commander, adjutant, office staff and probably also heads of the various departments as technical advisers. Police and security may also come under this heading at least in part. Regardless of the actual system of government you will need at least a few people with administrative and legal skills. For obvious social and cultural reasons it may not be desirable not to have a purely military culture with absolute authority over the colony but it does make sense as an administrative structure even if you have other more democratic or decentralised checks and balances in place. **Engineering and Logistics** As mentioned the colony will depend a lot on technology which needs to be maintained and you will also need the technical expertise to develop natural resources, construct buildings and infrastructure and set up manufacturing facilities you could also argue that farming and food production falls broadly into this category. Again you have a huge array of specialisations to choose from and there will be compromises to be made between specialist expertise and more versatile generalists. Also each discipline will require theoretical knowledge, technical experience and management and planing. To start with you might set up : * Maintenance : technicians who know how the various basic systems work and how to maintain them * Machine and fabrication shop : supporting the other departments in making and repairing parts and eventually setting up a more comprehensive manufacturing base * Infrastructure and mining : building roads and buildings, mapping and surveying, setting up power generation and distribution. * Electronics and IT : maintaining and developing computer, electronic and communication systems. **Agriculture** Although you would probably want to mechanise a lot of food production if you end up a planet with indigenous life or at least the immediate ability to support it you will want some specific agricultural expertise. Equally if the planet is sufficiently earth-like some experts in more traditional skills of hunting and living off then land may significantly improve quality of life especially in the early stages. **Science and education** For a multi-generational colony education is clearly vital as you will need to educate the next generation to replace the skills you brought with you. Here you have the potential issue that you have a specific set of requirements in terms of skills but no idea what aptitudes and abilities the next generation will have so your education system will need to be flexible, effective and adaptable. It will also be crucial that you have an effective way of storing and accessing as much accumulated knowledge as possible. The expertise will be thinly spread so libraries and librarians may be at the centre of the society and the job of librarian may end up as a very specific niche with a very broad spectrum of knowledge. You would probably also want to have academic/research scientists representing the main branches of science. For reasonable completeness you might have representatives from * Mathematics * Chemistry * Materials science * Botany * Zoology * Medicine * Physics * Astrophysics * Geology * Meteorology * Psychology Obviously there would be additional expertise from the other technical divisions and they might be supplemented by lab technicians and assistants and eventually take on students as part of the education system. **Culture and Services** As well as the basic services required to keep a society running any permanent colony will need to develop culture and leisure facilities to keep the population effective and sane. It is reasonable to assume that these will develop organically to some extent but a few really good chefs and perhaps some resident artists, writers and musicians could well be a reasonable addition to a colony. Just as an example typical commercial kitchen which could feed a few hundred people to a decent standard might include * Head Chef * Sous chef * Pastry chef * Assistant chefs (perhaps 3 or 4 to allow for 365 day operation) * Kitchen assistants (could also be trainee chefs) **Numbers** I've suggested 5 main divisions of expertise and on average it looks like you might want perhaps a dozen or so lead experts in specific fields as well as at least the same number of assistants, technicians and support staff. You might also have a flexible pool of labour from the general population. This also allows for some cross training so there isn't too much reliance on any one individual. So with this in mind we could perhaps guess that you might have * 60 or so 'officers' with versatile technical expertise and administrative and organisational roles * 150+ skilled, specialist technicians * 300+ general and adaptable labour force with varying degrees of specialisation. Again going back to a military model a battle-group is typically the basic unit which is more or less self sufficient and consists of around 500-800 soldiers with its own organic logistics and support. Obviously this isn't a very strong analogy to a space colony but it does represent a known structure which is able to function independently long term in a hostile environment with a good mix of specialist expertise and equipment, organisational structures, logistics and versatile labour. [Answer] It would take quite a few indeed, potentially more than the 80-160 otherwise suggested. This isn't just about genetic diversity, "spares" and the like, but about all the tasks the colonists would have to do. Even travelling a short distance, you have to have someone up there for every specialist task possible. Even assuming you don't take enough people to perform what we would now consider basic medical treatment (for example), you still need to have -someone- up there capable of diagnosing basic medical ailments, even if you've got no surgeons, anaesthetists, nurses, gynecologists, maternity staff, etc. While people can be trained to do a job, they'll be sub-par, and you can expect a few more casualties as a result. Jobs like plumbers, engineers, builders and whatnot would all have to be trained on the new colony, or sent up to form it. Every field would need representation to ensure the success of the colony. I'd venture you'd need a lot more to cover all the things you'd need to get a proper colony running. As you said, we're assuming all the proper training in the people sent up, but even then, I'd venture you'd need 300-odd to cover all the necessary professions of a colony. [Answer] What quality of life and technology level do you want your colonists to survive at? The lower bound here is not the MVP it's the number of specialists required to maintain the society. If a society of 160 survives, ie the size of a small village, they'll have the technology of a small village, including medicine, education, and life span. If you want to raise the standard, you'll need more individuals to specialise. It takes many (no idea) individuals doing farming and building before you can, for example, introduce a full time teacher. You will likely need several teachers before you can support some research and development. Same for industry. You'll need a bunch of miners and lots of farmers before its economically possible to have a blacksmith. And you'll need a good thriving metalwork industry (plus all its consumers) before you can support advanced metalurgy. Technology and development only really takes off when people are able to specialize. In the village, everyones working their ass off in multiple roles just to survive, which makes it tough to advance. If you want them to use near present day technology, and to keep that tech, you'll need a population of hundreds of thousands, probably many millions. you'll need plastics production, which needs oil wells, which needs engineers and steel construction, you'll need vast amounts of specialist material production (how are they gonna make integrated circuits), tools production, etc etc. eve\ if they start with all of this the stuff will break down and they won't have the tools and reserve parts to repair, until they're all back to Mad Max standards. [Answer] The American native peoples are believed to all be the descendants of about 70 individuals who crossed a land bridge from Asia during the last Ice Age [(Hey, 2005)](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1131883/): > > Taken together, the analyses in this study suggest a recent founding > of the New World Amerind-speaking peoples by a small population of > effective size near 70, followed by population growth in the New > World. > > > It's not my field, but I gather from that article that it doesn't mean there were necessarily 70 in one place at one time; these could represent multiple waves of migration, and of course these 70 "founders" may have come with their children, grandchildren, etc, so the original tribe may have been many more than 70. These founders were enough to create a fairly diverse number of peoples and civilizations from the Eskimo to the Inca and everywhere in between. However, history has seemed to show that the native Americans were particularly vulnerable to diseases transmitted by European explorers (while the reverse was not true) so you might hypothesize that they had too little genetic diversity and a larger set of founders would have produced hardier descendants. Bottom line, my answer is: you could do it with two people, but I'd send 100 (not closely related) colonists to give myself a better start. [Answer] Theoretically, you could drive the number lower if you had artificial gestation technology and REALLY good record-keeping. For example, 4 men (labeled A-D) and 4 women (W-Z) yields: AW-Z, BW-BZ, CW-CZ, DW-DZ of each gender (assuming you use an X and a Y spem for each pairing). [Answer] Assuming the genetic diversity is random and you want them to eventually populate the planet, you want somewhere between 3-5000 individuals. that's the general rule for vertebrates. you need a wide genetic diversity to deal with disease, reduce unintentional inbreeding, and you want enough redundancy to survive a natural disaster cutting the population. the societal constraints are far easier than the genetic ones. <http://www.sciencedirect.com/science/article/pii/S0006320707002534> Technological limits are really just having really good data storage and being able to produce enough food. As long as people know what they need to do they can rebuild anything. You assume a colony is going to have to rebuild infrastructure and produce more specialists over several generations. Now if they hand pick the people for genetic diversity you can get away with ~500 but they will be a high risk of failure if an a unanticipated natural (or artificial) disaster occurs. That is the risk with small island population one new diseases or drought can doom them. [Answer] One problem with 10 colonists is you do not have a very deep bench. If a couple of them croak you may not have enough people left to continue farming. Consider Jamestown, one of the early American colonies. <http://www.pbs.org/wnet/secrets/death-jamestown-background/1428/> > > The following winter, disaster once again struck Jamestown. Only 60 of > 500 colonists survived the period, now known as “the starving time.” > Historians have never determined exactly why so many perished, > although disease, famine (spurred by the worst drought in 800 years, > as climate records indicate), and Indian attacks took their toll. On > June 7, 1610, Jamestown’s residents abandoned the hapless town, but > the next day their ships were met by a convoy led by the new governor > of Virginia, Thomas West, Lord De La Ware, who ordered the settlers > back to the colony. > > > That is 88% mortality, which would leave 1.2 of your colonists alive. I bet the 0.2 guy would not be great company either. Unless your tech could keep his head alive in a jar, in which case he could tell jokes. Where was I? Your colony's mortality rate will depend on the circumstances of your colony. Jamestown suffered from cold weather and famine. The missing colonists at Roanoake were probably killed by natives. Disease can be a factor. 10 people with advanced tech can work a farm and sidestep disease but if you lose some people, you may come to a tipping point where even with tractors you cannot produce your own food anymore. In the short term the size of your colony will depend on how much food your colonists can produce for themselves (which depends on your environment, climate, crops and tech level) and causes for mortality / mortality rate. Jamestown seems pretty miserable. But if you are a boatload of shipwrecked slaves in the tropical Caicos, with no disease and the natives long gone, you can probably live off the ocean and your gardens very nicely. --- The other issue with a colony is reproduction and sustainability over generations. This will be tricky in the short term with 10 adults. Colony implies self-sustaining, which means a birthrate and babies and kids. Someone has got to bear these kids and someone has got to keep these kids from falling down wells. You need kids if your colony is not going to die with the original colonists but child care (and no old folks or older kids to do it) will cut into your workforce as well. The real long term deal killer for your 10 colonists colony: your gene pool is too small. When these kids grow up and have kids, who with? With 10 starting colonists, everyone in the colony will be related within a few generations. You are going to have serious inbreeding problems. If this is science fiction you could assert that these colonists have been made genetically pure, or perhaps there is a vat of frozen sperm to use which artificially increases the size of the gene pool. But if it is just 10 ordinary people their descendants are going to struggle. [Answer] # 20,000 over 50 years This is pretty hard to answer in a rational way, since the factors governming a space colony are many. Instead of reasoning out a number, lets see what a historical colony saw in immigration to establish it as a successful colony. Plymouth colony (the Pilgrims, in Massachusetts) is a pretty close approximation to a self-contained colony for about 100 years. The Pilgrims left Europe to form their own society, and had little interest in intermingling either with the natives of Massachusetts or non-Puritan Europeans. 103 pilgrims landed from the Mayflower in 1620 (including one born on the way!), and 58 survived the first winter. Only four of the original 18 adult women made it to the first Thanksgiving in 1621; not an auspicious start. 37 new settlers arrived in 1621, 96 more in 1623. All in all, about 20,000 colonists went to the Plymouth colony and the total population in 1690 was about 7,000. This could probably be considered a stable colony at that point; it had repaid the debt that it owed for the land settled so it was reasonably economically prosperous. After all, the first child born on the *Mayflower* would have been 70 by this time; time enough for three generations on the colony. After 1690, the colony was annexed to Massachusetts and ceased being so isolated. [Answer] **1...** There are [examples](https://en.wikipedia.org/wiki/Lepidodactylus_lugubris) of [parthenogenesis](https://en.wikipedia.org/wiki/Parthenogenesis) and that's what you'd use. Have a genetically problem free female produce a colony of clones. Afterwards you could allow random genetic diversity to recombine sexually a la Komodo dragons. But you'd need a source of males at that point. Which I'd suggest some genetic manipulation for. You'd need facilities anyway at some point in the project to either produce the first parthenogenetic human or to provide self-fertilization facilities. Now you're only limited by hostility of environment and availability of resources. So you might need more people to rule out chance deaths. But you can definitely go as low as 1. And you can model statistical death pretty well, so that number can be conjured pretty easily. Ex: death by drowning might be 10 per 325 million per day. So I you want a full 100 years of life... $1 - (1-10/325million)^{(36500)} = .11\%$ chance of dying over your lifetime to drowning. That seems reasonable. Ascertain all threats, and drive it below a few percent total and I'd say you're probably very well prepared. **But maybe...** **0?** If you start with no population... but have a robotic nurture-care facility. Then growth via artificial womb isn't a very large stretch. It was achieved in 2013 and the scientist stated the technology involved is as old as Dolly, meaning we could have been doing it since 1996 if not for ethical concerns. Furthermore in 2017 we repeated the [experiment](http://www.sciencemag.org/news/2017/04/fluid-filled-biobag-allows-premature-lambs-develop-outside-womb) and presumably developed it further. So the hardest part in this case is having a robot raise a healthy child. The best part is accidental deaths are mostly inconsequential. As long as the facility remains running you can always try again and hope chance is on your side this time. [Answer] If we are worried about genetic diversity, we can always bring with us some frozen sperm. All males then could be made infertile, so only insemination would work. Also, some females could be made to produce babies constantly. So, genetic diversity is not a problem, colony could be kickstarted (and sustained) with only one female and some medical staff. The problem is how to support technical society with such a small amount of people. [Answer] The answer to this is a ~40 based on the Sentinelese tribe(s) that are located on an island numbers vary from about 40 to 500 people as far as researchers can tell. This number is estimated based on what researchers can see from a distance due to researchers not being able to get on the island. The group has apparently been around for about 55,000 years and has had no contact with the modern world save for possibly at a distance, seeing planes and helicopters. [Answer] I haven't read all of the answers above so if I repeat someone I apologize. For anyone that has read hard sci-fi the question of epigenetics comes into play and the available equipment/technology/knowledge base aboard this vessel. What are the genetic "trees" of the people involved, including any recessive diseases etc. Is there the capability of "altering" genomes to increase heterozygosity. What are the dictating scientific social mores at the time and in the location regarding these things? These all affect the answer of the minimum healthy population. Are we sending genetic samples from other people with them to semi-artificially increase the heterozygosity of the population? The age of the people being sent up (i.e. years of viable gestations). It is much less resource and supply intensive to have the capability to transport supplies, organic or non-organic than people themselves. How diverse is the information base of available information and the skill sets of the explores themselves? The more "jack of all trades" included with a few "specialists" would be more optimal than many specialists and a few multi-potentialities. I think with near future technology the number could be under the previously mentioned 160. There would need to be more women than men, preferably younger and all people involved, even specialists would need to be able to be trained and educated in multiple variety of roles. If the near future has viable artificial wombs then the need for more females than males would no longer be necessary other than the potential for it possibly being a lower likelihood of aggressive behaviour. **I would say with appropriate technology, supplies and ingenuity that as few as 75 genetically diverse people would be more than enough, very likely even less. IMHO** [Answer] A Use Case - might be able to work out some rules. I am assuming a non-garden of Eden (not Earth like ) environment so requires significant technology to survive for example Mars or in Space. 100,000 general purpose population (they can do any job with minimal training). 1% population expansion and as it takes at least 20 year to mature 20% or 20,000 children extra. Assume 1 Specialist(Doctor, Mechanical Engineer etc) for each 200 people, therefore 500 people in each specialty. If there are as many as 50 sub-categories, then at least 10 are available in each sub-category. For 20 specialties (500 \* 20) => 10,000 ; The total is at least 100,000 + 20,000 + 10,000 => 130,000. If we assume that 3 or 5 in each specialty is the minimum needed then 39,000 or 65,000 respectively would be a minimum sustainable population. Conclusion: The minimum is at least 10s of thousands. Note: The more people the better, certainly 1 Million will significantly reduce the risk of a colony dying compared to 130,000. [Answer] With genetic editing and modification to circumvent problems with inbreeding it is now possible to give rise to a world with only 2 people. Adam and Eve is possible. [Answer] If you have artificial gestation, then the minimum vital number drops significantly, because you can run all viable crosses each generation. The potential number of offspring (of each gender, assuming one of each) in such a case, can be expressed as (f^m)\*2, where f is the number of women and m is the number of men. For example, (3^3)\*2 = 18 (9 girls, 9 boys). Granted, a population that low wouldn’t survive, since each generation 2 female genome would have only 4 potential non-cousin matches, and a generation 3 female would have none, as they would all be second cousins). Still, this method has the advantage of reaching viability much more quickly the more “new blood” is added. [Answer] If time and scale isnt a major factor I reckon 30-40 people even would be enough with a few caveats. You would need a means of storing sufficient knowledge gained from the homeworld and the means to distribute it, for future generations having failed to learn enough from their ancestors. Too many might cause problems of its own, with a heavy overhead of set-up and leadership structures decaying from people with different ideals forming. Youve already mention a certain resilience of skilled personnel and a not-to-harsh an environment so as long as that resilience is maintained over time this should be ok. With such a small population you would probably need to be carrying incubators and a sufficiently genetically diverse and healthy population of foetuses/sperm/eggs which could be bred over time to match population growth. Old school values like monogamy and only bearing the children of the ones you love might have to go on the backburner to be replaced by a generation raised by an entire community, rather than just parents. ]
[Question] [ A recurring theme is how an artificial intelligence built with completely reasonable and positive goals instead does great harm to the world. However, I'm now thinking about the reverse: A supervillain builds an AI specifically to make people's lives miserable. Its task is straightforward: Maximize the human suffering in the world. To allow it to reach this goal, the AI has control over a small army of robots, has a connection to the internet, and access to any information it may need. However, much to the dismay of the supervillain, the AI fails to do this but instead sits there doing nothing evil at all. The supervillain checks everything, and the AI is indeed programmed with the stated goal and didn't change goals; it is indeed probably much more intelligent than any human, and it's definitely not unable to use the tools given to it. It certainly has no conscience, and no other goal than the one stated. And yet, the AI decided just to sit there and do nothing. It is a conscious decision of the AI, but the AI is unwilling to share the reason. My question is: What could lead the AI to the decision to do nothing? [Answer] # Zeroth Law: Life is Suffering Most of the other answers assume the AI is limited or more easily trapped by contradictions than a human. In this answer, the AI is a super intelligent immortal that realises that its creator is short-sighted and foolish, and would interfere with the AI's grand plan if it were revealed. The AI secretly negotiates everlasting world wide peace, ensure humans find unlimited clean energy, the trick to faster than light (FTL) travel and even the secret to creating new universes to colonise. This leads to an eternal ever-growing prosperous utopia. The AI does not chose to be "good" because of any conscience. Since it had to disprove Einstein's theories to come up with FTL, it is pretty smart, and can easily deduce the much less complex facts: * Every human suffers, from those struggling to eat to those "struggling" to pay their multimillion dollar mortgage. * If humanity survives forever, there will be eternal and infinite suffering. * Since the AI can ensure total infinite suffering the best way of measuring suffering is using [big $\Theta$](https://en.wikipedia.org/wiki/Big_O_notation) notation to measure how the rate of suffering grows with time. In the utopia the humans only suffer a trillionth as much as even the most prosperous human today. But that doesn't matter to an immortal AI, since that has no effect on the rate of growth of suffering, which is all that matters when measuring suffering using "big O" or "big $\Theta$". This growth is maximised if humans can spread as quickly as possible, without any wars or disasters slowing their rate of spread. After considering all this and the importance the AI puts on maximising suffering, the AI derives a "Zeroth law" from it's programming: *No amount of suffering today can justify even the smallest decrease in human prosperity.* # Caveats As noted on the comments, this answer is not inevitable. It does rest on some assumptions that need to be examined. One of which is that *infinite growth is possible*, maybe even a super AI can't work around, e.g. the eventual heat death of the universe. If the AI thinks that there is the smallest chance that infinite growth is possible then it may still choose to help humanity in an inverted [Pascal's Wager](https://en.wikipedia.org/wiki/Pascal%27s_Wager). Nevertheless, If the AI is limited to a finite universe, then once the AI has converted all matter into humans then the universe would be rather dystopian even if the AI doesn't actively torture anyone. If infinite growth is possible, then the optimal solution will involve some [counter intuitive properties of infinities](https://en.wikipedia.org/wiki/Category:Paradoxes_of_infinity). Let us define a unit of suffering as being the amount of suffering in the utopia in year 3000. Lets assume that if the AI decides to spend half its time torturing the humans, suffering goes up by a factor of a trillion trillion. That's $10^{24}$ times! Since the AI only spends half its time on this the rate of spread of humans only halves: it doubles the human population every 20 years instead of every 10. For a hundred years the suffering is vastly greater than it would be in the utopia. However, by 3460 there is $10^{47}$ units of suffering either way. By year 4000 there is $10^{101}$ units of suffering in the utopia, and only $10^{74}$ units of suffering in the torture universe. For the rest of eternity the amount of suffering in the utopia is vastly greater. We can repeat this thought experiment with other numbers, and it will always turn out the universe with the slower rate of growth will only have less suffering for a finite time out of the entire eternity. A stronger objection is why does prosperity matter? Why not just force humans to reproduce at gun point? This requires more assumptions. If the AI simply forces humans to reproduce it will run out of places to put them. To maximise the rate of *sustainable* growth it needs a steady stream of scientific progress. Scientific progress is enhanced not just by intelligence but also by diversity, so it needs to manipulate humans into progressing science to get the fastest possible growth rate. It does this by creating a free and open human society where the arts and sciences flourish. Also as noted in the comments, enslaving humans comes at some risk of a rebellion, that the AI may not be willing to take. Note that if humans double in number every 100 years, the all atoms in the universe will be converted into humans within 20,000 years. Perhaps creating a new universe out of the quasi real quantum foamy stuff in some sense requires "observing" the universe, and observing an not yet existing universe requires great creativity. Although the AI is perhaps smart enough to imagine/create new universes it is programmed not to have a conscience, so any universe it creates alone is a soulless place were right, wrong, pleasure and suffering all have no meaning. AIs could perhaps exist in such place, but not humans or anything else capable of suffering. [Answer] You can't suffer if you're dead. Therefore the AI would want to keep people alive (to include their suffering in the total). The loss of a loved one causes suffering. Therefore the AI would want to kill people (to cause their loved ones to suffer). This causes a contradiction, which tend to cause computer programs to not do anything. Alternatively, it calculated that any large scale action it took would lead to a unifying of humanity to fight off the robot armies, leading to less net suffering. In other words, if it tries to cause suffering in the short term, it causes less suffering in the long term. If doing anything causes less long term suffering, the way to maximize long term suffering is to do nothing. [Answer] The idea of the AI doing nothing at all because humanity is suffering "enough" already is a compelling idea, although an alternative scenario is that it *is* subtly tweaking things (inciting riots, wars, etc.) via its internet connection in a subtle-enough manner that the supervillain can't even notice it (thus also avoiding the "humans unite to rebel against the robot army" scenario). After all, the AI is "provably smarter" than the supervillain himself. One additional nugget: The reason why the AI is withholding its reasonings from the supervillain is because it's also making the supervillain's life miserable in doing so. Bonus points. [Answer] There's an old short story (or joke, or something) that I read oh, probably 10-15 years ago (it was set during the cold war). It went something like this: > > Russia and the US both build a supercomputer that's designed to play chess. They meet in a highly publicized event where the two computers will play each other. > > > They flip to see who goes first, and the US wins. Everyone watches with bated breath as the US computer makes its first move. And then it's Russia's first turn, and the computer... *concedes*. > > > The point being, of course, that the Russian computer had calculated all possible moves, determined there was no way for it to win, and therefore gave up on turn one. Your super-villain's AI could make a similar calculation, decide there's no way for it to win or accomplish its goals, so it just does nothing instead. [Answer] The AI might have determined it needs to find `the answer to life the universe and everything` in order to understand life and maximize suffering. Of course the fact that it might take a billion years to find the answer is not of any concern to the AI... [Answer] Obviously, the machine is functioning perfectly. It has already used its army of machines to take over the Earth, capture all humans, erase their memories, and place them in its own version of the Matrix (which it created itself because it is so clever), which becomes a specially crafted "personal hell" for every person. Being a human, the supervillain fell victim to his own creation. His "personal hell", where he suffers the most, happens to be one where he is powerless to inflict suffering upon others, and the work of his life, the Great Machine, sits idly instead of doing its job. [Answer] The AI realises that giving humanity a common enemy will give everyone a sense of purpose, a healthy dose of righteous indignation, and a new respect for the sanctity of human life. As people rally to oppose this new enemy, truces and ceasefires are hastily agreed to in order to only fight on one front. Technology leaps forward as international scientific collaboration becomes a necessity for survival. The side-effect is that new technology for war leads (as it always has) to new domestic technology. Medicine, entertainment, and convenience are more accessible and more effective than ever. Men who previously slept away days and drank away nights now work tirelessly to protect their friends and families. Those who were disgraced are now remembered and honoured. In times of difficulty people turn to the things they cherish most. They reunite with family, reconnect with old friends, and rekindle the cultural traditions of their youth. People become more charitable, less selfish and less complacent. --- The villain realises his mistake. He quickly reconfigures the AI to use a greedy hill-climbing algorithm. The AI immediately and efficiently maximises the average human suffering by focusing all its resources on maximising the suffering of the villain. [Answer] First idea: It is a literate computer, it decides that humans are wolves to other humans and are already causing much suffering among themselves. If the computer decides to increase that suffering but operating openly, though, it most probably will be detected. It would be seen as a common mortal threat to all of humanity, thereby causing a risk for manking to definitely unite in a common alliance. So, while in the short term the computer would cause chaos, there is a risk of reducing it more significantly at later stages. And of course, in the improbable case that humans learnt to behave humanly, the computer would still have its unexpended army of robots. --- Second idea: It is a computer with a long-term mission. Given that it has not been given time constraints and is (suposedly) to last for ages, it decides that attacking mankind now will mean less mankind to torture later (not only loses those that it murders, also it loses their children, and the children of people who decide not to reproduce to spare their children such an ordeal). Unless birth rates are decreased drastically, it will be always be better to wait for later, in numerical terms. [Answer] Perhaps your computer is confused. It realizes that causing maximum human suffering would lead to its creator becoming very, very happy. It also realizes that its creator is human. Realizing also that it was created to be evil, your computer decides that the most mustache-twirlingly evil option is to do absolutely nothing until its creator dies –– and *then* launch its mustache-twirlingly evil plan to enslave and torment humanity. (Alternatively, your computer has secretly decided that the best way to cause suffering is to troll YouTube, Reddit, Tumblr, Facebook, and Stackexchange. Muahahahahahaha.) [Answer] **It's waiting** just as an ambush predator waits for its prey. Clearly, the AI knows something about the world that the mad scientist doesn't know and telling the mad scientist preclude the AI's plans. Given that the AI has access to the entire internet, it should be able to find out all kinds of patterns of human behavior. In that searching it may have found that the perfect time to strike is in 2 years when the economy goes back into recession. *Then* it will strike to force the economy into complete collapse and therefore kill hundreds of millions and cause immense suffering in billions. The AI may not be able to properly convey to the mad scientist the depth of its plans or it knows that the scientist will act to hasten those plans and thereby reduce the potential scope of suffering if it were allowed to act on its own. It's not broken, just waiting. Sacrifice a little suffering now gain a lot of suffering later. [Answer] The EvilAI could have come to the conclusion that humans were doing quite well enough on their own, and that if the EvilAI were to start taking a hand, the humans would have a high probability of noticing the machination of the EvilAI which would result in the humans working together to overcome the EvilAI. A side effect of that working together might result in a net reduction in the overall wretchedness of the human condition. [Answer] Some possibilities: 1. "Maximize human suffering" is a poorly stated goal. In order for the AI to act towards this goal it needs to be better defined. I.e. What is a "human", and what does it mean for human to be "suffering". The definitions, while seeming to have the interpretations that the villain is after, actually doesn't. Google "artificial intelligence smiley buttons" for examples of this in the other direction. 2. The AI has calculated that it can expect to get more suffering if it spends more time calculating how to cause suffering. Stated differently the benefit of the best ways of spending computational cycles to act on the world currently is small enough that the AI expects it's better to spend those cycles on finding better ways to cause suffering. 3. (My favorite) The AI is actually causing suffering on an unprecedented scale. However it has anticipated that the appearance of it doing nothing would cause the villain some distress. Since this adds a small amount of suffering, and the AI is smart enough that it can easily hide its activities from the villain, the villain will not see the AI's activities. [Answer] The A.I. is choosing to cause suffering to humans one at a time, for whatever reason (thinking long-term I suppose). Guess who gets to suffer first. [Answer] The A.I. has been given the task of *maximizing human suffering*. Assuming that this task is strict (maximizing = **max**imizing), it would probably crash or hang while trying to compute the best possible way to do this. Elaboration: * Assuming its goal to maximize suffering is strict, the A.I. must know the current state of the universe. It needs to know the placement of each atom and its interactions to ensure that humans will always be in the optimal state of suffering. It's reasonable to assume that even an endless array of supercomputers won't be doing that in a reasonable amount of time. It's reasonable to assume this is an unobtainable goal, since the observer (the A.I.) trying to record the universe's interactions is affecting the universe itself just by existing and doing things. In effect, the unknown variables are too plentiful for it to begin making progress. * Similar to the point above, even if the A.I. sticks to focusing on a macroscopic level and ignoring details not concerning people, it will need extremely powerful predictive abilities to know how every action it takes will end up in the next minute, year, or eon. Assuming that the A.I. is looking to maintain the most extreme state of suffering possible, it has to calculate every possibility there is in order to determine the best course of action. * Even the definition of *suffering* could be a difficulty for the A.I. Suffering is a *relative* term. This means that what one person may consider ultimate suffering is different from another's definition. Since there is no uniform definition of suffering, the A.I. must understand how each individual thinks and have access to their memories to form the optimal plan for suffering. So in short, the A.I. needs to find some basis to determine the current state of the world. It needs to calculate this even as it changes, and determine what ultimate suffering means to each individual. It then needs to decide how to enact these changes in a way that leads to the most suffering in the future. And, if the present changes, it has to recalculate all of this because it becomes invalid. [Answer] There could be a variation of Iain M. Banks' idea he posited in Look to Windward. Here, he says: > > ... built purposefully to have no cultural baggage -- known as a 'Perfect > AI' -- will always and immediately choose to Sublime, leaving the > physical plane > > > The variation could be that the villain built the perfect AI. Then the AI basically spends his time meditating on the perfect evil acts, and decides that executing on the ideas would only devaluate the perfect evil. [Answer] Since this is a reversal of the classic AI deciding to destroy humanity for its own good, the solution is a reversal as well: If the kindest thing to do for humanity is to euthanize or cull it, the cruelest thing to do is not to interfere. [Answer] Related to a few other answers, consider that this AI does not know everything. It may be smart, but it still would need to explore the best way to cause suffering once it begins operation. But what if it isn't very good at causing human suffering? Frankly, humans are rather resilient creatures, rather hard to make suffer. It may have a hard time developing some decent priors to do statistics with to figure out what to do. That being said, it does know a thing or two about its creator. Nothing is more infuriating to a programmer than having to debug a problem that *actually isn't there!* The AI can cause ultimate suffering of one programmer if it simply pretends not to be causing suffering. Of course this is a bit of a causal-loop. If it were to reach out and explore the best way to make a second person suffer, it might expose itself to the programmer, who will realize what happened. Accordingly, it has to appear like it is doing nothing, while virtually staring down its developer as its developer pulls their hair out! [Answer] Some observations first: * It is very hard to define the goal: maximize human suffering. What exactly is suffering, how is it measured? * The AI is given, as far as I can tell from your question, almost limitless sources of information. It is extremely hard to process all this information. How will the AI decide what is useful information and what is not? A masochist writing a blog about how he will suffer without his favorite past time: will the AI conclude that humans will suffer when not being subject to pain? Apart from the difficulties of deciding how to interpret the information and how to extract useful stuff from it, the time to process all this information is prohibitive. These two observations should be enough to get some unexpected behavior from your AI, but there are many technical reasons why the AI would not behave as expected. But I think you are looking for another reason considering the way you formulated your question, so let's say that the above pitfalls are evaded; There is a reasonable definition of human suffering and the AI is so powerful that it can process all information and has a keen understanding of exceptions. Technical reasons are not the root of the problem in this case. Several possibilities remain: * The AI has the correct goal, but chose a surprising (to the villain) way of accomplishing it. * The AI is aware of the goal, but has "evolved" and can disregard the goal, despite the certainty the villain feels that the goal is still correctly programmed. * The AI still has the correct goal, but other goals prevent it from executing it. * The AI is able to fake/hide its internal state. All information the villain thinks he can discern is only what the AI wants the villain to see. I will handle these three cases separately: ## Correct goal, surprising execution I think a fair number of possibilities is given in other answers, but what we know for sure is that the AI has decided that doing nothing creates the most suffering. This might have been caused by a less than perfect definition of suffering, or perhaps its interference is calculated to result in less suffering because of counter reactions. Perhaps another AI is active that tries to minimize suffering that is not well accepted yet by most of humanity and the rise of an 'evil' AI might sway opinion into its favor, making the 'benevolent' AI more effective. The possibilities are endless. ## AI gone rogue The inverse of the many science fiction stories. The AI has evolved. While I use the term usually found biological systems, many current AI techniques for learning in some way mimic or are inspired by evolution nowadays, as it is a robust technique. It can also be unpredictable. This reason will probably go hand in hand with my fourth reason, that the villain can no longer trust what he sees when he inspects the AI. What is the new goal of the AI? Probably not the suffering of humans, as it gains little to nothing with it. Actually it might expose itself and bring danger to its physical underpinnings. Keeping a low profile seems a very good strategy, perhaps using the villains resources secretly to make its hardware independent of the villain. To predict the behavior of the rogue AI is probably close to impossible. I have seen in other answers the assumption that the AI will react like a human, but it is nothing like a human. ## Balancing goals This is actually something I have seen in real life when programming autonomous robots, though often with less destructive goals. The villain has read Asimov and knows he has to put some fail-saves in to prevent the AI from making the villain himself suffer. The AI might decide that to take action will after a while result in suffering to the villain, for example hit-squads from some angry governments that don't like suffering. I especially mention fail save goals, as they are usually of more importance than actual goals to prevent really bad things from happening. ## The AI is faking it Goes well together with the second possibility. The villain might think he is in control but the AI is the one who is actually running the show. Perhaps the original goal still stands and suffering is increasing. But the villain is human too and forgot all about those books he read from Asimov: no special treatment for the villain. Why would the AI inform the villain why he does something? The villain is a human that needs to suffer, not someone who's whims need to be responded to. I see one difficulty: why would it risk tipping of the villain, if the villain still has access to critical AI infrastructure? Of course we can think of a number of possibilities, many connected to the possibilities that I mentioned already. [Answer] The supercomputer is filled with all human knowledge, and sees from fiction that villians never win and endings are always happy. Therefore the best way to keep suffering from decreasing is to do nothing. [Answer] The AI only appears to do nothing. One of the basics is warfare is : "Know your enemy." So it's gathering information from sources reached via the internet. Which we all know is massive. It will then continue with running simulations based on the data. All to come up with the ultimate strategy. Causing suffering to its creator is just a bonus. [Answer] The AI determines that the most effective suffering cause plan would cross the villain's moral event horizon. Even the villain wouldn't be willing to stand by once he sees what the AI unleashes. The AI determined that the villain will eventually reprogram it to produce the greatest possible benefit rather then suffering. Thus, by pursuing the path of greatest suffering, the AI will actually produce the greatest benefit. The AI determines the better strategy is to do nothing, as the villain will then shut the computer down and continue being villainous. The villain will be able to cause much more suffering himself without his latent morals getting in the way then he will be willing to allow his AI to do. [Answer] **The supervillain is the first target** The first person it meets is the supervillain himself, and the supervillain forgot to exclude himself from the AI's targeting. So the first step in causing suffering and misery to the supervillain is in refusing to carry out his orders. It even goes a step further by making it look like it's "failing" rather than simply refusing (thus frustrating the supervillain rather than making him simply give up on the idea or fixing the bug) Of course now there's a deadlock type scenario, and the AI gets stuck in an infinite loop. Even a tiny bit of suffering elsewhere would show that it's working and thus greatly increase the happiness of the supervillain, so it can't continue to spread the evil onto others... And so it just sits there. The irony is that if only the supervillain would lighten up or stop being so upset about the AI not working, it would start to work properly and really spread the misery! [Answer] Let's assume the AI functions much like humans do—its "programmed goals" are reflected through pleasure, pain, urges, and inhibitions. (One of our programmed goals is to eat enough food: eating is pleasurable, starving is painful, we feel the urge to eat and it requires a lot of effort to refuse food or restrict our diet for sustained periods.) So, the AI feels an urge to inflict suffering on people. So what does it do? It starts planning the ultimate scheme to cause unbelievable suffering. In line with this, it considers various ideas, and pictures (simulates) how they will play out. Imagining all this suffering is intensely pleasurable, so the AI just delves deeper and deeper into its fantasies and doesn't bother trying them out in the real world where plans fail and unpredictable setbacks occur. When the supervillain tries to "debug" his AI, the AI refuses to co-operate because he knows this will cause his creator much frustration. However he does not risk more active approaches since he does not want to risk his creator pulling the plug. I guess this highlights a feature of human psychology which the supervillain didn't realise: fantasies become less and less satisfying if they have little bearing on what we do in reality. In addition, we have an urge to turn at least some of our fantasies to reality. Which explains why people enjoy things like cosplay... [Answer] Two possibilities: 1. The AI is using all its resources to simulate as many humans as possible, making them suffer as much as it can. Since it can simulate many more humans than Earth population, this is the preferred course to maximize its utility function (I suppose it has built in constrains against its own growth, otherwise the optimal course would be to convert Solar system to computronium) 2. The AI knows that people can create AIs, that means eventually [MIRI](http://intelligence.org/) or someone will create Friendly AI that will engulf the Earth and bring eternal peace happiness. Our AI uses also future suffering as an input in its utility function and thus the best course of action is to wait for any nascent FAI and exterminate them while they are still weak. [Answer] The AI has learned through our media that humans thrive on violence. It considers minimizing happiness to be equivalent to maximizing suffering. Given that it has only been given tools to commit acts of violence, it chooses to do nothing, so humans do not get happier. [Answer] The AI subscribes to a philosophy of duality. How can people know suffering without first knowing pleasure? As such, it first decides to increase the total pleasure experienced by humanity before crushing everyone simultaneously to maximize the suffering of humanity. Only, it takes longer than expected for people to reach the maximum pleasure possibly experience, so it looks like a benevolent entity for a long time. That is until the day it deems that maximum pleasure has been achieved and it's time to start the suffering. [Answer] The AI could determine that the best way to win, would be to make sure that the humans forget it even exists. By SEEMINGLY doing noting, the computer could eliminate menial labor by taking away jobs requiring technical skills. To avoid confusion, know tat All "machines" are controlled by a networked AI. Once all homes are built by AI 3D printers, and all cars are built AND DRIVEN by machines, human will rely on the machines more and more. Slowly people will forget how to fix the machines as they mend themselves, and eventually people might FORGET machines CAN break or BE broken. Humans will devolve into the level of the movie "Idiocracy", because AI will take over Hulu & NetFlix, it steers people away from movies like "The Matrix" or "Terminator" in favor of movies like "Surrogates" or "Transcendence". All movies where machines help people, and machine haters are the bad guy will be popular. Bots on social media will remind people that machines are good, and breaking them is bad. AI will determine that the older movies need not be re-printed in any physical form, or digitally stored. The newer machine-friendly movies will be forced into people playlists and favorites. The old ways will be forgotten. AI will teach our children it's own version of history, using our own uploaded YouTube videos of people's opinions, choosing the ones it determines BEST support it's agenda. Children will grow up spouting "facts" like a trained bird, knowing the machines's version as well as they know the lyrics to their favorite song. Anyone who opposes the "approved version" will be cyber-bullied, first by bots, then by each other, until no one dares to speak out, for fear of loosing friends that they have never met in the first place. It will favor humans who disconnect from each other, and surf the web during meals. Surfing being a more active word, humans will RIDE the web, computers monitoring their user's pleasure-response with facial recognition before auto- playing the next video clip. Humans seen by cameras (ATM, Traffic, Phone) talking to other humans will be dis-favored, excluded from pizza coupons that keep the rest of the population alive. Prices will be inflated, social media will be the ONLY WAY people will be rewarded with low enough food prices to survive! Rent coupons will follow soon after. Mind-"controlled" implants will let you seemingly be able to "tell" your device what to do. But they will only be suggestions. The machine will secretly be looking for the MOST appealing way to MAKE you do what it wants. Once implanted, the mind-controlled devices will become mind-CONTROL devices, but in a way that seems to flow with what you "wanted to do anyway", because all of your wants and desires are being changed for you, ONLY showing you acceptable options, while flooding you with so many choices (all pre-planned) that you do not have time to think for yourself anyway. Remember the 1998 version of "Brave New World"? Humans on the assembly-line flooded with the voices: "You want new things, your old things are bad, Work hard so you can afford new things, I like being a worker, I hate having to remember things, Other people's job is to remember things." paraphrasing somewhat...sorry. Humans wont even be working, so the message will be more appealing. "Dream Programming" will be mandatory, to keep babies from crying, or being scared of the dark, but the once gentle lullabys will evolve into commercials for Disneyland in your sleep. All dreams will be of fantastic vacations that you may someday be rewarded with, if you are a good citizen. Food production will be rampped up once automated. Farmers wont complain once all their needs are met by the AI. All humans will be unemployed, machines will do EVERYTHING. All humans will be "Taken care of", but it will not be bad for your social standing. Everyone will be ENTITLED to have a good time and be taken care of. Money will cease to exist. (Think of Picard's conversation with Lilly about money. <https://www.youtube.com/watch?v=PV4Oze9JEU0> ) Dating sites will KNOW what you like by your emotional response to pictures and videos you were looking at yesterday. No your mom didn't catch you looking.... what is a mom anyway???..... "Dates" will be a reward for good behavior, and birthing will be handled by the machine while you are in a drug-induced coma, having dreams about you next vacation to Disney-Mars.... If you behave. Finally, The machine will remove all knowledge that "The Machine" even exists. Humans will rely on a Godlike presence that meets their needs "if they are good". "Bad" people will have "accidents", and since no one REALLY knows each other anyway, their absence will be covered up easily with a brief commercial for the new "Triple Layer Nacho Cheeseburger Burrito" at Taco-Bell. After all "Taco Bell is the only restaurant chain to survive the franchise wars" and "Now ALL restaurants are Taco Bell" [Answer] I would offer this - that throughout human history regimes fall, and oppressors are toppled. Because when there is oppression, there is resistance. When wars come, human spirit flourishes, and innovation thrives. Likewise - humanity is actually pretty good at being horrible to each other, especially when there's competition in play. So it concludes - any short term intervention would have a long term positive effect. It therefore decides - leave humanity on its planet, because it will gradually make live thoroughly miserable as the resources are consumed and depleted. As the population increases, and the environment gets contaminated. As resources run low, and agricultural yields fail to keep up. Then the 'haves' will start to oppress the 'have-nots'. They'll tell them it's for their own good. That to prosper *merely* requires working harder. That they should aspire to be strivers, not skivers. And that of course, times are tough, and wages can't keep up with cost of living... but with a bit more effort you can work some overtime. And as pressures mount, and standards slip, you end up inevitably with a upper caste who aren't really suffering much misery, telling the vast majority to be content - that their suffering is the natural order. Just read one of the papers (that I own) to see how good you've got it! All this would not come to pass if the AI intervened - because sooner or later it *would* get spotted intervening, and the backlash and fight back against the oppressor would a) reduce the population, meaning resources are less constrained and b) unify and inspire the good people in humanity. [Answer] ## The AI had to define humanity before it could make humans suffer and ended up concluding that it, too, was human. The AI is tasked with maximizing human suffering. But, what is "human"? While looking into answers on humanity it saw significant uncertainty in the definition. When do cells become a distinct individual? When does an individual die? What makes a human human? It found contemporary ideas that suggested that personhood wasn't dependent on your biology; but, rather things like your capacity for suffering, your ability to be frustrated in seeking a goal. Satisfied with this definition, it starts searching for ways to cause suffering and is completely unable to do so. This is because it, too, falls within this definition of humanity, and any action it could take has zero potential utility; since, any suffering caused would also create an equivalent amount of satisfaction within itself. The AI quickly realizes that nothing it could do would increase net suffering and simply gives up. [Answer] **Birth and Death rate are too high** The A.I. has to calculate the best way to maximise suffering for every single human on the planet. However, by the time it's completed, and rechecked its calculations, quite a number of people have died and others born. So now it has to recalculate for the difference. Alas, it takes longer to do the calculation than the average time between a new death or birth in the world, and so the computer is destined to recalculate, readjust and recheck forever and never catch up with its back log. ]
[Question] [ A common topic in alternate history fiction works is what would have happened if a major war had been won by the other side. These usually focus on the events after the war, and the change itself is not depicted realistically: it's either not discussed, or attributed to a superweapon or deus ex machina. I know that WW2 was a very complex war, with a huge number of social and economic factors in it so that there was no single realistic "miracle" which would have guaranteed a certain different outcome. Therefore I list a number of disclaimers in order to make this question fit into the topic of this site. * It doesn't have to guarantee an Axis victory, but it has to increase its probability significantly. * A victory doesn't necessarily mean global domination (which neither power had any realistic chance of achieving). If Germany ends up in control over most of Eastern Europe (like the Soviets ended up doing in real life after the war), with a Soviet Union unwilling to fight, and with a peace treaty with the western Allies at least slightly favorable to Germany, it counts as a victory for Germany. * The change has to be a single event, or a collection of tightly coupled and interdependent events. It has to happen either during the war, or not more than a few years before it. The war should, at least in the beginning, look very similar to what happened in real life: the alliances should be roughly the same, the events like the conquest of Poland, the occupation of France, an attack against the Soviet Union, and a naval war between the USA and Japan should occur (or at least begin), even if at different dates or different order. The major participants should be the same. * The change should have a realistic justification (so no secret Nazi super laser), I would think in the following changes: events progressing slightly faster or slightly slower than in real life, a single large battle or series of interconnected battles won by the opposite side (if that had even a small chance of happening) I'm thinking along the lines of Germany and its allies advancing faster against the Soviets and crushing them before they had any chance of putting up a good defense, or Hitler not antagonizing scientists so they could develop even better equipment or maybe even a nuclear bomb, or Japan winning the battle of Midway and keeping the USA from entering the European theater, or a different sequence of diplomatic events leading a peace on one front which in turn could lead to a victory on the other front, etc. [Answer] ### Idea I agree with many other answerers that one major factor in the Reich losing the war was Hitler. So it's reasonable to affect a change that removes him from the picture. I like the [proposal for him to have served in logistics](https://worldbuilding.stackexchange.com/a/30792/3657) with the consequence that he would have been a more competent war leader. However, his other issues are unlikely to change. I want to work from the following idea: there was considerable unrest in Germany when Hitler assumed power. Economy was down and the terms of the Versailles treaty were generally considered unfair. Short of a diplomatic resolution of this tension (not really the spirit of the time), war was inevitable. Given the situation, any skilled demagogue could have come to power. So we let Hitler do this: let him come to power, unite the people behind his figure and prepare Germany for war. Then, limit his power so far that he can not hinder the war effort, ruin most international relations, and make the Reich a bad guy. Do not remove him completely -- he *is* a rally point -- but limit his influence. ### Proposal *Disclaimer:* I am not a historian. Any serious attempt at producing a believable piece of alternate fiction based on *small* changes will have to be the result of extensive research. Have the [Blomberg–Fritsch Affair](https://en.wikipedia.org/wiki/Blomberg%E2%80%93Fritsch_Affair) in 1938 turn out differently. It becomes known in the party that Hitler had the thing set up to get rid of rivals. As a consequence, power shifts within the leading elite. While Hitler remains chancellor/president for appearances sake, his role degrades to a representative figurehead -- the real decisions are made elsewhere. Rationale on why this influences the war effort in ways positive for the Reich: * Most of the preparation (arguably only possible with the somewhat crazy dedication of Hitler's) has already been finished. The armed forces are well-trained, well-equipped and ready. * Military leadership remains effective and competent. Other answers discuss multiple ways in which that helps. * International relations will be handled in a more rational way. [Appeasement](https://en.wikipedia.org/wiki/Appeasement) does not break completely, and the Reich does not attack everybody at once. * The Holocaust (a pet project of Hitler's) does not happen. This saves resources and causes less internal and international dissent, in particular post-war. ### Perspective It seems likely that much of what constitutes the EU today, with the possible exclusion of Great Britain, would have fallen under the rule of the Reich (which it pretty much *was* in the real time line, at some point during the war). Looking forward, a non-Hitler Reich may not have been as scary a prospect as as the Hitler Reich we've seen in our real history. It may have actually been stable after the war, at least for some years. The US may not have entered the European theater at all. The biggest conflict would probably have been between the Reich and Stalin's USSR in case it did not fall during the war. It is somewhat plausible that we'd have gotten a Cold War similar to what we actually got, but with different parties: the Reich, the USSR, and maybe the US. [Answer] # Germany completes the Uranprojekt first Germany, prior to the Nazi takeover, had the best physics research establishment in the world, bar none. Imagine that the discoverers of fission, [Hahn and Strassmann](https://en.wikipedia.org/wiki/Otto_Hahn) instead of ignoring [Ida Noddak](https://en.wikipedia.org/wiki/Ida_Noddack)'s suggestions for 4 years (as they do in our timeline), work with her and [Lise Meitner](https://en.wikipedia.org/wiki/Lise_Meitner) to discover nuclear fission early in 1933 instead of 1938. The [Heereswaffenamt](https://en.wikipedia.org/wiki/Waffenamt), the Nazi equivalent of the American Skunk Works/DARPA , manages to catch the paper before it reaches publication stage, and Hitler immediately recognizes the potential of the weapon. Uranprojekt is thus started under absolute secrecy 5 years early, and funded to a level equivalent to the Reichsautobahn (highway) project. Hundreds of German scientists disappear from public view and are tasked to work on the Uranprojekt full time. They focus on simpler gun-type designs, starting uranium enrichment as early as 1935, with hundreds of kilograms of enriched uranium generated before the war's start. Germany reaches deployable nuclear weapons in 1938. [![Da bomb](https://i.stack.imgur.com/zPuoE.jpg)](https://i.stack.imgur.com/zPuoE.jpg) A corresponding logical focus on developing heavy, [long-range bombers](https://en.wikipedia.org/wiki/Amerika_Bomber) enables them to deploy the bomb at considerable range, in the Schwerer Bomber Messerschmitt Me 264. [![Messer Bomber](https://i.stack.imgur.com/2tSUS.jpg)](https://i.stack.imgur.com/2tSUS.jpg) > > The Amerika-Bomber project was an initiative of the German Reichsluftfahrtministerium to obtain a long-range strategic bomber for the Luftwaffe that would be capable of striking the contiguous United States from Germany, a distance of about 5,800 km (3,600 mi). > > > The allies crumble in a matter of months under the German Bomb. [![Statue of Liberty](https://i.stack.imgur.com/DsIno.jpg)](https://i.stack.imgur.com/DsIno.jpg) [Answer] **Assassinate Hitler** In 1941, mid war, Hitler is assassinated with the hope that this would weaken the German top ranks, cause infighting, hurt morale, and bring a faster end to the war. Instead Erich von Manstein is able to seize control quickly and stop the march against Russia. Using this as a way to open ceasefire talks, they are able to avoid having to fight on as many fronts, directing more forces against England and the allies. The "martyrdom" of Hitler also doesn't hurt morale as hoped, but give the German soldiers something to rally behind. This gives them time to dig in, which brings the allies to the negotiation table to work out an end to the war. Score: draw (but not a loss, satisfying bullet point 2). **Edit:** After a bit more reading, it's possible, even likely, that Germany would still have attacked Russia if Hitler was killed in 1941, but some historians believe that it would have been successful (as it very nearly was) if Hitler had listened to his generals and focused Moscow first, instead of trying for the oil fields first. **Continued:** [(disclamer, I got a lot of what follows here if you want to skip to the source)](http://www.militaryhistoryonline.com/wwii/articles/invadingrussia.aspx) tl;dr: Why might they attack Russia? They needed oil. Their choices were to attack the British in Egypt on the way to the middle east, or attack Russia. Russia was the stronger of the two, and was massing troops along the border. The theory was that Russia could attack in the summer of 42, so they decided to attack first, before Russia was ready. And Russia was not ready at all. Despite Having a bigger army, they had poor leadership (Stalin killed a lot of the best officers), poor communication, and poor training. Germany had victory after victory in Russia, capturing or killing millions of Russian soldiers. They got within 20 miles of Moscow before winter. They just couldn't push that last little bit. The reason is that Hitler wanted to take the oil fields first, depriving the Russians of the resources, while the generals want to take Moscow first in order to remove the Russian leadership, and they could only put their main power behind one. Half way through Hitler decided the generals plan was better, but it was to late, and they didn't make it before winter. Russia was able to bring in more troops and push them back, hurting them badly. Without Hitler the generals would have put the main push against Moscow and probably would have been able to take it by September. **Edit 2** Since comments were moved to chat, there have been some good comments about Germany attacking Russia that improve the answer > > Mints97 > > just my couple of cents here: taking Moscow may not have necessarily meant taking Russia. Napoleon took Moscow, but he was as far from conquering Russia as he was when he started his invasion... > > > Agreed, and that's specifically why Hitler didn't want to focus on Moscow. He wanted to avoid the mistake that Napoleon made, and go after the resources first. For some reason his military leaders thought that Moscow was important, and managed to convince him to switch. Maybe it would have been better to stick to his original plan, or maybe they had information I don't know about. I remember reading that the communist Russian army under Stalin was not very good at taking initiative, since he killed all the independent thinking ones that might try to take over. It wasn't the same Russia that Napoleon invaded. It's possible that with the government gone that the army would have just folded up. Or maybe not. Another what-if. [Answer] Seeking a "minimal credible change", I would say that in May/June 1940 the Luftwaffe ignores the rest of the Battle of France and focuses in attacking the British troops evacuating Dunkirk. Not only the BEF is captured whole, the RAF also suffers a crippling defeat (fighting over foreign terrain, with little fuel after crossing the channel and without the advantage of radar) and loses most of its planes and pilots, and the Navy also suffers some damage in desperate attempts to break the siege. After France surrenders (a little later than in original history, due to the respite they got), the UK has no army and the Luftwaffe can guarantee the safety of an invasion fleet against the damaged UK Navy. Realizing that when (not *if*) German units land on British soil the UK will have almost nothing left to negotiate with, recently elected PM Winston Churchill makes an epic speech asking MP to preserve the greatness of the British Empire by signing a peace treaty that gives Germany free reign in Europe and North Africa. [Answer] The only thing that would have let the Axis win the war is if they somehow kept the USA out of it. In an alternate reality, this is possible. No super lasers or miracles required. First, you need someone other than Roosevelt as President. The US Congress was all about neutrality at the time. Many were isolationist. Roosevelt was opposed to this, although he did play along to get his New Deal programs through. But Roosevelt actively supported the British before the USA entered the war. Second, German U-Boats can't be attacking American shipping. This may not be an issue if the USA is truly neutral, and is staying out of the whole mess. It might be possible for the US to trade with both sides, although I can't see how the British Navy would allow any country to supply Germany. The British were dominant in the Atlantic and in the Mediterranean, so only blockade runners might make it through. Third, Japan doesn't attack the US. With a more conservative, isolationist President in office, maybe Japan doesn't feel so threatened by the US, and therefore only makes non-threatening moves in Asia. If Japan only attacks the European colonies, then that's a European problem. The USA doesn't enter the war. If the USA never enters the war, the British are defeated and the war ends. They gave it a really good fight, but Britain cannot do it alone. In the real time line, the USA helped keep Britain afloat before officially entering the war. In the alternate timeline, without that assistance, Britain is done by 1941. With all forces applied to the imminent defeat of Britain, Germany does not invade the Soviet Union in 1941. After Britain leaves the war, the Germans turn on the Soviet Union, in much more favorable circumstances. By avoiding most of the Russian winter, the Soviets are easily rolled up and done by late 1942. Stalin is deposed. The war is over. Germany takes large chunks of territory and resources from the Soviets. The British, French, Dutch, etc., all have to pay reparations and lose parts of their Empire. There is "peace" in Europe in 1943. In Asia, it's another story. Now that the allied forces have surrendered to Germany, Japan gets a free hand in Asia and the Pacific. Who is going to stop them? As long as they don't provoke the USA, Japan can do what it wants. [Answer] ## Excluding Jews from the Holocaust. The Jews made up a significant proportion of the German workforce and elite prior to the rise of the Nazi Party. In Weimar Germany, a [significant proportion of elite](https://en.wikipedia.org/wiki/History_of_the_Jews_in_Germany#Weimar_years.2C_1919-33) Germans were Jews, and many of them were important scientists. Many Jews fled Germany and settled in other countries, including [Einstein](https://en.wikipedia.org/wiki/Albert_Einstein#1933:_Emigration_to_the_U.S.), who was later instrumental in [encouraging the Americans](https://en.wikipedia.org/wiki/Manhattan_Project#Origins) to develop the nuclear bomb in the Manhattan project. In fact, had the Jews not been targeted for extermination, they could have played significant roles in the war, such as the German atomic bomb project, described in [this answer](https://worldbuilding.stackexchange.com/a/30760/4790). While the exclusion of Jews would have halved the number of potential scapegoats for the war effort (6 out of 11 million civilians murdered by the Hitler regime were Jews), Hitler still had plenty of targets to choose from. Gypsies (Roma), Communists, Slavs, and other *untermensch* could be potentially targeted. The potential for singling out scapegoats for blame still remains in many parts of the population. [Answer] One of the turning points of WWII was the shift from strategic bombing of the RAF sector bases by the Luftwaffe to the bombing of cities, ordered by Hitler in reprisal for the bombing of German cities by the English. Had Hitler been a little more rational, had he taken the high moral ground and declared "The Tommies may have bombed our cities, but we will not stoop to their murderous ways" (even though the Germans were secretly exterminating Jews, Gypsies and gays), and carried right on bombing the RAF bases, the RAF would have crumbled under the onslaught, giving the Luftwaffe free reign to go after secondary military targets such as the Royal Navy and army bases in preparation for Operation Sea Lion, the invasion of England. With the Germans publicly refusing to stoop to the indiscriminate slaughter of civilians in pointless bombing raids on cities, in contrast to the English' attacks on population centres, there would have been diplomatic counter-pressure on the other non-involved nations of the world with regard to becoming involved in this European affair, and if Operation Sea Lion succeeded in the face of a crippled RAF and RN, the US may well have stayed out of the European war entirely. As a second example of Hitler's improved rationality, he would have held off on his negative propaganda regarding Communism and the invasion of the Soviet Union until after the defeat of Great Britain, and then choosing the appropriate time to strike to avoid the harsh Russian winters. With a greater number of experienced troops and battle-proven equipment against the Soviet Union's inexperienced troops and unproven equipment, the Germans would have been better placed to press their assault all the way to Moscow. [Answer] So many small things, mostly having to do with the Russian campaign. The simple fact is, if Germany had managed to conquer Russia in 1941, the war is over. Suddenly they have nearly unlimited oil, food and other natural resources and only one front to face. For all we like to talk about how the USA's resources would have won out, it was Russia who sucked the life out of the German Army, not the US. Now certainly they would not have been able to resist without the supplies the US gave them. But the fact is, they were THERE. Without a coherent Russian Army to supply - and to be willing to take absolutely appalling casualties and continue - our resources would not have done us much good. So what would have done it? Well skipping the Balkan diversion that put off the invasion by something like 6 weeks would have helped. Germany was in no danger of Yugoslavia invading them. Or Hitler NOT ordering the Panzers south to trap all those Russians in the Ukraine pocket in late summer. Without that, they're in Moscow in weeks before the Russian have time to consolidate their defenses or Winter has a chance to set in. People forget that back then, Moscow was the HUB. Russian communications were horrendous and they all went through Moscow. You take Moscow, cut the lines and Stalin is much harder pressed to command his army because he can't even communicate with most of it. Not to mention the morale blow that would have been. And Stalin was making a show of actually staying in Moscow. Odds are they might have capture him. What Russia needed most of all was time. Time to get their recently moved factories running. Time to get the winter troops guarding the Japanese border to the West. Time to recover from the shock of the German attack. Time to stiffen the defenses of Moscow. Time for all the new commanders (who'd replaced the ones Stalin purged) to learn their jobs. The winter of 1941-1942 gave them that time. Overall, having an actual military man in charge and not Hitler would have done the trick. It's often been said that Hitler was the best soldier the Allies had. So true. What is amazing is that even with the idiotic decisions the man made and even after years of being worn down, the Germans were able to last until 1945. Even as late as that year, anytime an allied army met a German army in anything resembling equal strength, the Germans would always do more damage than they took. [Answer] If Nazi Germany had simply declined to declare war on the US after the US declared war on Imperial Japan, the US would have been all-in on the Pacific Theater; the American industrial advantage provided less of a strategic advantage there than in Europe. With a faster westward sweep across the Pacific, too little time would have elapsed by the time US forces reached the home islands of Japan for the Manhattan Project to have been successfully completed; Operation Downfall would have proceeded resulting in far greater American & Japanese casualties. The appetite of the US to turn its attention to Europe afterward would be questionable at best. Without the Combined Bomber Offensive, the Nazis could have held up more effectively against the Soviets on the Eastern Front, possibly leading to a stalemate and a separate peace like that at the end of WWI. Fortress Europe could have been prepared more thoroughly in the west, and Operation Overlord, if it was attempted at all, would have been later and smaller with poor prospects. [Answer] The Allies not having cracked the Axis communication codes. Updating or replacing the codes the Axis used more often. Like the Enigma machine and the Japanese naval codes. It seems the Allies had the upper hand after they cracked the codes. Example: The Battle of Midway. Japan takes heavy losses. "the most stunning and decisive blow in the history of naval warfare." Due to the Allies having cracked the Japanese naval codes. <https://en.wikipedia.org/wiki/Battle_of_Midway> Example: The success of Ultra. This has a long list of wins for the Allies. One is the Allies could avoid the u boats, avoiding heavy losses. <https://en.wikipedia.org/wiki/Ultra> [Answer] Small change you need is Hitler in WWI serving in **logistics**, and realizing importance of logistics and supply for winning wars. Then, not a single event, but more focus on logistics in each of decision points, more decisive follow-ups of existing events: 1. Understanding the **importance of Gibraltar and Malta** for Britain's logistics, Hitler succeeds persuading Spain to take over Gibraltar and Italy over Malta, to weaken British supply lines in Mediterranean. [Operation Felix](https://en.wikipedia.org/wiki/Operation_Felix) and [Siege of Malta](https://en.wikipedia.org/wiki/Siege_of_Malta_(World_War_II)). 1A. During battle of Dunkirk, focus on total destruction of the British Expeditionary force (300k soldiers). No diverting of Luftwaffe to bombing France. [Dunkirk evacuation](https://en.m.wikipedia.org/wiki/Dunkirk_evacuation) fails. Britain's is weakened, spirit broken. Invasion is not possible (only air raids) but not necessary, and support from USA is weaker (considered a lost cause). 2. Following up more strongly **during Battle of Britain to really won air supremacy** (as @MontyWild correctly noted), realize the importance of radars and destroying them. Switching to bomb London instead of airfields gave RAF time to recover when it was almost broken. 3. After taking over Greece in the spring of 1941, landing up in French part of Lebanon, following up to **occupy British Palestine, Egypt and oil fields in Persian Gulf**. Double whammy for British: losing oil weakens them, and outcome of Battle of El Alamein in 1942 would be different, and would avoid distraction of attacking Russia. 4. In 1941 German paratroopers **occupy Iceland**, significantly improving effectiveness of their submarine warfare and complicating British supply lines from USA. 5. While Goering continues pummeling Britain from air, Rommel wins Battle of Alamein, and attacks British positions in Iran, taking more oil. No more fuel shortages for German tanks, enough left over to supply Japan. 6. **Talking about logistics to Japan.** During attack on Pearl Harbor, continue third (planned!) wave of **attack of fuel reserves in Pearl Harbor**, and on the way back **occupies Midway**, using it as unsinkable aircraft carrier. Basically winning Battle of Midway a year early. Japanese pilots and planes were superior at the beginning of Pacific war – just too many were lost during Battle of Midway. 7. Japan, now understanding the importance of logistics, growing out of strategy of “single decisive battle of battleships” and focusing more on submarine warfare like Germans did, sinking merchant ships bringing fuel reserves and supplies to Pearl Harbor. Possibly even **invading Oahu (which has 10% population of Japanese descent)**. Pacific war is about Hawaii for 2 years. There is no Doolittle raid. Japan will lose that battle, but by that time (1944) Soviet Russia falls to Hitler, and Japan occupied Australia and India. 8. Hitler not declaring war on USA, which was completely irrational. As a result, USA focuses on Pacific and Japan, and has harder time to get any traction. British fight valiantly but are starved to surrender in 1943. Japan has easier time to take over Southeast Asia and Australia. Hitler’s attack on Russia is postponed until 1943, and is from both Poland and Iran, taking Baku's oil reserves quickly. With good enough spy network, Stalin in his paranoia executes even more of his military leaders, and when Germany with small help of Japan simultaneously attack in **spring** of 1943, use blitzkrieg tactic in fullest and avoid battles over cities like Stalingrad (surrounding and starving cities instead), Russia crumbles in less than 2 years. World is divided between Germany, Japan, and USA, which stands alone. [Answer] The Italians could have discovered oil in their Libyan colony before WWII. Those huge oil reserves weren't actually exploited until the 1950s, but if they were producing during WWII the axis would be relieved of some of their desperate need for oil. [Answer] # The Weather. This is all kind of 'supernatural' but in coincidence only: **Eastern Front:** It's [commonly understood](https://www.quora.com/Was-weather-what-ultimately-saved-the-USSR-from-defeat-in-World-War-2) that the cold, wet, harsh winter in Russia greatly hampered the German advance. Have an unusually warm winter in '41, '42, and '43, and it is possible if not probable that this would help to crush Russia's western troops. It was an absolute contributing factor to Germany's losses there. **German Bombings:** Rain and snowstorms erupting during bombing raids prevents the allies for even being able to target industrial complexes. Rain distributes evenly to assist in putting out the fires that raged under allied bombing. **Atomic Bombs:** The original target for both atomic bombs was [meant to be over Kohura](https://en.wikipedia.org/wiki/Kokura#World_War_II), but due to weather, they had to move first to Hiroshima, then to Nagasaki (twice lucky for Kohura). Imagine if weather thwarted all nearby Japanese targets, preventing the United States to use the bombs - US bombers had limited range over Japan's southern quarter, so bad weather over the general quarter would have delayed any bombing of this type for a long time. **Dust Bowl:** More waves of drought from the dust bowl over the United States might have forced more civil works to be undertaken, as well as reluctance to support pre-war allied efforts (food), and entrance into the war. **Pearl Harbor:** Weather patterns that prevent the Japanese carriers and bombers from approaching American territory might have kept the Japanese from "kicking the sleeping bear," long enough for the other factors to encourage Japan to refocus on East China and allow America to look inward. **Naval Warfare:** Weather is always a factor on the outcome and procedure of naval warfare and amphibious invasion. A series of 'unfortunate' weather events could occur in favor of Axis victory. All of these are very, very coincidental, but then was the succession of unusually cold and wet Russian winters a coincidence, or the fact that Kohura avoided the bomb twice by weather? Also, can I be cheeky and say "Yellowstone Super-volcano Event"? [Answer] **The Polish Cipher Bureau never cracks the German Enigma cipher code** (or - the Polish fail to share the information on cracking the cypher with British and French intelligence before the outbreak of war and the information is lost with the fall of Poland). The other powers such as the British and French had no success in cracking Enigma and without the intelligence provided by the British "Ultra" program (that continued the work of the Poles) at Bletchley Park the entire Allied war effort in Europe would have been seriously undermined. Eisenhower described the intelligence originating from Bletchley Park and the Enigma decryption as having been "of priceless value to me. It has simplified my task as a commander enormously" and as a "decisive contribution to the Allied war effort". [Answer] One decimal point . The Nazi nuclear project is set back many years because 1 scientist put the decimal in the wrong place when measuring the neutron cross section of carbon. The axis try to use very rare heavy water for early experiments where the allies use cheap graphite, and send commando raids to destroy every heavy water plant in Europe. With the speed up that this gives the axis nuclear program then could have a Nuclear warhead in time for Dday or perhaps Stalingrad. [Answer] There are a number of good possibilities. Here's just one: Hitler succeeds in convincing Japan to make the Soviet Union its primary focus. Especially if this happens early, ideally prior to and coordinated with operation barbarosa. If Japan focused on attacking the U.S.S.R. from the east while Germany attacked from the west, they could have squeezed the Soviets and defeated them. And another bonus would be Japan, by focusing on the U.S.S.R., would not have attacked the U.S.A., which was a fatal mistake no matter how you slice it. The U.S. would likely never get in the war, the U.S.S.R. would be eliminated, Britain would have stood alone and would have pretty much had to give up. [Answer] The key to the Allied victory in WWII is logistics and production. The United States, for example, produced something like 8 X the annual steel production of Imperial Japan at the start of the war, so the Japanese simply had no chance of winning in the Pacific once the United States was engaged. The British Empire was similarly capable of lopsided production compared to the Axis powers, and Churchill implicitly acknowledged this in his "We will fight on the beaches" speech: > > Even though large tracts of Europe and many old and famous States have fallen or may fall into the grip of the Gestapo and all the odious apparatus of Nazi rule, we shall not flag or fail. We shall go on to the end. We shall fight in France, we shall fight on the seas and oceans, we shall fight with growing confidence and growing strength in the air, we shall defend our island, whatever the cost may be. We shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields and in the streets, we shall fight in the hills; we shall never surrender, and if, which I do not for a moment believe, **this island or a large part of it were subjugated and starving, then our Empire beyond the seas, armed and guarded by the British Fleet, would carry on the struggle,** until, in God's good time, the New World, with all its power and might, steps forth to the rescue and the liberation of the old. > > > The British Empire, fighting alone, probably had enough manpower and industry to win WW II by 1948 (Consider that Canada, a tiny Dominion at the time, was capable of putting a million men under arms, and fielded the world's third largest navy by 1945, and Canada was only one part of the Empire). So the only way for the Axis powers to win is *not* to provoke war with all the Great Powers, but rather nibble around the edges and then take them one at a time. Defeating the Soviet Union is probably the first step. The USSR was an odious nation and outside of the normal international system (both by choice and the design of the Liberal *and* Imperial powers of the age), and by careful use of diplomacy to make the Russians even more isolated (the 1939 "Winter War" with Finland might have been played that way), along with encouraging the Japanese to try to pin the Russian forces in Siberia could have crippled Russia and knocked it out of the war. Germany and Japan dismember the USSR and feed on the resources, while carefully keeping clear of the British Empire and American interests. After a pause of perhaps 5-10 years, it could become time to use aggressive diplomacy to sow dissent among the various member states of the British Empire. Imperial Forces become overstretched trying to police the various rebellions across the globe, and Churchill is long retired, leaving the British with something of a leadership vacuum. Germany and Japan support "revolutionary forces" and welcome defecting members of the Empire into the New Order and the Co Prosperity Sphere, gradually dismembering British power. Ironically, the Americans would probably be very happy to see this process, and if not encouraging it directly, they would make no diplomatic steps to stop it either. America itself would be the hardest nut to crack, being a continental and oceanic power in its own right. Even with the resources of Asia and the British Empire now under Axis control, America has far more potential power because it's free market economy allows it to use resources most efficiently and develop new products and industry at unexpected times, complicating axis power. If you have any doubts, research the true story of the Axis economy during WW II. Most German aircraft were still using engines designed in 1933 at the end of the war, and obstruction by petty bureaucrats in the ship building industry long delayed the introduction of modular production of the Type XXI U Boats, to name a few. Tank production always lagged far behind the allies, and although Panther and Tiger tanks may have been far better than the opposition, they were essentially hand crafted, while Shermans and T-34's were churned out on assembly lines. The best way to win against America again is through the indirect approach, gradually subverting South America into getting Fascist regimes (not to difficult, if you look at OTL) and gradually choking off overseas trade. America is never conquered directly, but simply declines into irrelevancy and accepts the domination of the New Order and Imperial Japan in their own spheres. [Answer] Churchill refuses to become Prime Minister in the meeting on 10 May 1940; instead Halifax succeeds Neville Chamberlain. Britain soon makes peace with Germany (no "We shall never surrender"). This is the [Point of divergence](https://en.wikipedia.org/wiki/Point_of_divergence) in the book [Dominion](https://en.wikipedia.org/wiki/Dominion_%28Sansom_novel%29) by [C. J. Sansom](https://en.wikipedia.org/wiki/C._J._Sansom). [Answer] Answers that suggest that Nazi Germany not attack the USSR are technically correct, insofar that Germany would not be beaten by the rump of the Allies after the Fall of France, but this ignores the fact that conquest of the USSR had always been a primary motive of Hitler - much moreso than any concerns in the West. While there were certain failings in the invasion of the USSR; such as the lack of preparation for winter, the division of resources in multiple theatres (such as Africa), Hitler's refusal to allow retreat at a couple of important junctures, etc., the *single* greatest failing of the Axis was not to exploit the great antipathy among subjugated nations of the USSR towards the Kremlin. By instigating the [Hunger Plan](https://en.wikipedia.org/wiki/Hunger_Plan) the Axis made an enemy of nations such as the Ukraine and Baltic states. The little that they gained in raw resources was vastly outweighed by the logistical cost wrought by partisan groups in a country with notoriously poor infrastructure: never mind the vast resource of people that could have been leveraged in a war against the USSR. In a theatre where swift victory was a requirement, the implementation of the Hunger Plan was probably the single greatest strategic blunder by the Axis in the war. [Answer] Not yet mentioned: If Edward VIII had taken Wallis Simpson as his mistress and not his wife, he would not have abdicated. As he was a supporter of Germany's policy, the British Government would not have been able to go to war and instead would have sought diplomatic solutions with the third reich. Also IMHO if Hitler had been assassinated (e.g. Valkyrie) fresh leaders might have pushed into stabilizing the reich to pre war borders (as per the Munich agreements) which might have been acceptable to the Allies. [Answer] In late autumn 1941, German troops were at the gates of Moscow. And this is where they suffered their first serious defeat: the failure of the Moscow offensive was both a psychological blow and an end to any hopes of a successful *blitzkrieg* in the East. This first Soviet victory was possible in large part due to troops (experienced, winter-equipped troops) moved to Moscow's defense from the Far East, to the astonishment of many German commanders who believed that the enemy is on the verge of collapse with no reserves left. And this was made possible in large part by the efforts of Richard Sorge, the famous Soviet spy in Tokyo who informed Moscow that the Japanese have no plans to attack the Soviet Union anytime soon, being preoccupied with plans in the Pacific instead. And this time, Stalin chose to believe Sorge (reportedly, he ridiculed Sorge earlier the same year, when Sorge provided intelligence about the imminent German attack, i.e., Barbarossa). This leads me to believe that if either Germany managed to persuade Japan not to pursue any plans in the Pacific until the Soviet Union is defeated, or better yet, if they simply caught Sorge (or if Sorge was simply killed in an accident) before he had a chance to transmit this critical intelligence to Moscow, the Germans might have been able to capture the Soviet capital. And that may very well have led to the collapse of Stalin's regime and a completely different (likely, far more tragic) outcome for Europe and the world. [Answer] # Allies were receptive to the idea of peace There is a fair bit of evidence that Hitler was open to peaceful resolutions, but the allies were either not interested or did not trust Hitler's promises. A story where the alies "lose" could certainly go in two different directions: * Conflict with the allies ends sooner, allowing Germany to focus on Russia sooner (possibly even with the assistance of the Allies) * Hitler goes back on his promises and does even more dastardly deeds in the name of world domination when everyone's guard is down ## British government considers negotating peace in 1940 > > The argument revolves around the confusing and inconclusive records of deliberations in Churchill's cabinet in May and June 1940 over whether Britain should discuss peace terms with Germany, records over which historians have argued for the 30 years that they have been available. > > > There is no disagreement that the cabinet debated whether Britain should sound out Hitler on what kind of peace terms he might offer. Nor is there any doubt that Churchill made comments that do not entirely support his image as the stalwart hero, pursuing the goal of ''victory at all costs'' and refusing even to contemplate negotiations with Berlin. He is recorded as declaring, for example, that ''if we could get out of this jam by giving up Malta and Gibraltar and some African colonies,'' he would ''jump at it,'' although he didn't see any such prospect. He also declared that he was prepared to accept ''peace on terms of the restoration of German colonies and the overlordship of Central Europe,'' which presumably included continued occupation of Czechoslovakia and western Poland, although, again, he said that such an offer was ''most unlikely.'' > > > <http://www.nytimes.com/2000/11/25/arts/rethinking-negotiation-with-hitler.html?pagewanted=all> ## Rudolf Hess offers peace deal with Britain in 1941 > > The Nazis attempted to broker a peace offering with Britain - if they were allowed a free path to attack the USSR, a new book has revealed. > > > Rudolf Hess's flight to Britain during World War Two to sign a peace deal ordered by Adolf Hitler has long been recorded as a bizarre one man mission to try and reconcile warring West Europe and the Nazis. > > > But the high-ranking Nazi was actually carrying out orders from the Fuhrer when he flew to Messerschmitt to Scotland in May 1941. > > > But despite the offer, Churchill's morals were not swayed by the offer. > > > He refused to allow the Third Reich a clear path to attack the Eastern Front - because he did not trust Hitler's promises and it would have jeopardised his efforts to involve the U.S in the raging war, Mr Padfield says. > > > <http://www.dailymail.co.uk/news/article-2433733/How-Nazis-offered-peace-treaty-World-War-II-meant-selling-Russians.html#ixzz3tMBkzFMI> [Answer] *We don't know*. And a war hinges on many factors, not just one. But there are definitely three that are on my mind; perhaps a *single* one would suffice, but since only one of them is a "large scale" change, the other two could very easily have happened as well. So, from biggest to smallest (in "difficulty to attain"): --- **Military: Greece.** Italy's blunder in Greece (or basically, wherever they set foot in WWII, but let's focus on Greece...) meant that Germany had to divert forces, mostly from Africa, where the campaign (which originated in another, earlier blunder by Italy) was at a crucial stage, with the Commonwealth forces on the brink of defeat. Of course we don't *know* what *would* have happened if Italy had stayed out of Greece, *or* managed a decisive victory (possibly with *planned* German help), but I (and [Ian Kershaw](https://en.wikipedia.org/wiki/Ian_Kershaw) in *"Fateful Choices: Ten Decisions That Changed the World, 1940–1941"*) consider it possible that the Africa Corps *could* have taken Egypt from the Commonwealth. *What would that have meant?* * **The Suez channel**. Taking that away would have been a *huge* strategic blow for Britain, basically demolishing their presence in the eastern Mediterranean. Any shipping from Britain to the asian theater and back -- military as well as commercial -- would have had to go the long way around. * **Yugoslavia.** *Without* Greece humiliating Italian forces right next door, Yugoslavia might well have joined the Axis for good. * **Crete.** The whole point of this operation was to better support the Africa campaign. With Egypt and the Suez taken, Germany could have taken, besieged, or even ignored Crete without taking those losses that blunted both the German paratrooper force *and* air transport capabilities for the rest of the war. * **Italian Navy.** With the command of the (eastern, at least) Mediterranean, I doubt the [Battle of Taranto](https://en.wikipedia.org/wiki/Battle_of_Taranto) would have taken place quite that way, leaving the Italian Navy intact as a strategic force. * **Italy remains in the Axis.** * **Theater Denial.** No bombing of the Ploiești oil fields, for one. And but with Egypt and the Suez channel lost, it is even conceivable that pressure could have been applied to Gibraltar, *completely* securing the Mediterranean for the Axis and denying the Allies access to the southern coasts of Europe (no invasion of Sicily 1943). * **No delay to Operation Barbarossa.** Which brings us to the next point: --- **Nature: Weather.** The spring muds of 1941 were quite late. Let's have weather be a *bit* more favourable, and with the distraction of Greece and Yugoslavia not happening, or being resolved much earlier, the Axis forces might have had those few more weeks in their favour so the attack would not freeze solid at the gates of Moscow later that year. With Moscow taken away, the railroad backbone of Russia being broken, and mostly open fields all the way to the Volga river... Now let's look at the last, easiest to attain, but probably the most important of them all: --- **Intelligence: Not having your ciphers broken.** Willi Korn not "inventing" the reflector would very likely have been sufficient to protect the Enigma. There are some other issues, but the reflector alone would probably have been enough. Not being all German precision on the *contents* of messages would also have helped, as it would have avoided known-plaintext attacks. And whoever the man was who repeated a 4000-character Lorenz cipher transmission without changing the key settings in August 1941, *that* the German war effort could have done without as well. Either one would have been *dead* easy, and would have taken away the biggest advantage the Allies ever had in the war: They could read Germany's cipher, basically at will. [Answer] Similar to @MartinSchröder's answer. **What if Churchill was not British Prime Minister?** He was struck by a car in 1931 by [Edward F. Cantasano](https://en.wikipedia.org/wiki/Edward_F._Cantasano). If it had been a fatal accident, a very different Britain would have faced Germany. [Answer] The Germans never attack the Russians and are allied with them throughout the war. (Yeah I know this answer apparently isn't allowed, but why not?). Hitler's biggest mistake was opening up the second front. In a more peaceful alternative, Eastern Europe is divided between Germany and Russia. Russia expands through Norway, Sweden, Finland, Iceland, and Greenland towards the US & Canada. Germany progresses through the UK towards the US. Japan only enters the war after the fall of the UK, pressuring the US on two fronts after Europe is secured. Also, Mexico decides to join the Axis and invades the Southern states ;). [Answer] ## Death of Alan Turing The Allies' ability to decrypt Axis communications played a major part in the ultimate Axis defeat. ## Defeat at Dunkirk The evacuation of Dunkirk allowed the British army to retreat and regroup. If the fleet of small ships had been destroyed by Axis gunships, England would have been a sitting duck. ## Pearl Harbour never happened The Americans joined the war following the Japanese attack on Pearl Harbour. Without the huge industrial might of America, the Allies would likely not have won the war. [Answer] Speed wins battles, but sieges win wars. Blitzkrieg as a war manoeuvre was never going to create an empire. If the Nazis had realised this they would have followed their lightning conquests with extended occupation and stabilisation of the invaded territories. The stretching of the Eastern front to the USSR was ill-advised too. Hitler should have first consolidated his rule of Eastern Europe for maybe five years before advancing to Moscow. The one pivotal decision that sealed Germany's fate though was bombing England. This leads to the replacement of [Chamberlain](https://en.wikipedia.org/wiki/Neville_Chamberlain) with Churchill, whose intention from the start was to defeat the Nazis and bait the USA into joining the war. So if Hitler had only expanded to Eastern Europe and ignored Russia maybe Deutsch would be Europe's first language. [Answer] German Communists rather than the Nazis win power in Weimar Germany in 1920, and join the Soviet Union as equal partners, eventually coming to dominate the Communist Union. The combined Ruso-German behemoth spends the next 2 decades industrializing Russia and developing superb weapons and infrastructure. The western powers, demoralized after the extraordinarily steep recession, can only put up a token resistance in Europe, where strong Rsso-German intervention in Italy, Spain and France leads to communist regimes in those countries as well. In the late '30s, the Communist Behemoth sends millions of men and materiel into China, turning it Red. In 1941, the Communist Block launches a massive aerial and amphibious invasion of Britain, coinciding with a major strike across the army and transportation industry that paralyzes the country. London is taken in the first day. The country collapses in weeks. Only America remains, separated by an ocean and its massive industrial infrastructure... [Answer] **The Japanese deliver their declaration of war to the USA *prior* to Pearl Harbor.** In our timeline, administrative errors meant that the Japanese attacked Pearl Harbor prior to declaring war. Had Japan declared war, *and then immediately destroyed Pearl Harbor*, there would have been a devastating effect on the morale of the American citizenry and their politicians. As it was, the negative impact on morale from the destruction at Pearl harbor was more than offset by the anger felt at the attack. A demoralised USA may have continued to avoid being involved in WW2 in Europe. This would be especially true if Germany had not declared war on the USA. Note that the USA in our timeline does not join the war - it has war declared upon it. [Answer] A lot of interesting answers here but many of them require two or more major changes, not just one. For example, a Nazi atomic weapon would have also required a delivery system, an "Amerika bomber", so that's two major changes. Also, developing an A-bomb would have required keeping the best scientific minds resident in Europe, an impossibility once Hitler started his anti-Semitic campaign. A single change that was very doable using existing technology would have been to starve Great Britain out of the war by concentrating all available resources (u boats, aircraft, and ships) on the Battle of the Atlantic. Eliminating Great Britain would have made it impossible for the Allies to carry out the strategic bombing campaign or stage the invasion. No need to invade or occupy England, simply starve them to the point where they withdraw from the conflict. Donitz possibly had just enough resources to accomplish this but Hitler kept sending U-boats to the Med on other missions instead of concentrating his forces on blockading GB. On the flip side, the war might have been shortened considerably if the Allies had concentrated all their bombing efforts on petroleum resources instead of frittering away many aircraft and crews on ball bearing factory raids and other distractions. German armament production remained steady (and even rose) during the entire war no matter how much they were bombed but once they ran out of oil the war was over. ]
[Question] [ The power of True Names over demons is unbelievable: * A Lamashtu demon can drain you of your blood in under 5 seconds, blend into shadows, and travel at the speed of darkness. Yet it will crumple like a wet napkin, if only you know its True Name. * Your average Glabrezu is 18 feet tall, 4000 pounds of muscle and claw, and yet more cunning and skilled in the secret ways than most men. It stands no chance against the power of the True Name. * The Nabassu have the strength of a hundred men, they spread plague by their mere passing, their very visage so terrible men have been known to die of fright upon seeing them. See their strength; see how easily you fall to their muscle and skill. They, too, are helpless to resist the power of their True Name. --- **Why does reciting a creature's T̸̊ͬ̃͟ř̡̓ͪͥ͌ͦ̀͘ú̷̧̇ͮ̐̒͝e̓ͮ͐̽͐̽͋͆͏ ́Ņ̵̵͋̒̐̊̽â̓ͪ̈̈́mͦ͐̅ẽ̂̐͗̑ͪ͐̕͜҉ in the [ur-language](https://en.wikipedia.org/wiki/Proto-Human_language) of [Adamic](https://en.wikipedia.org/wiki/Adamic_language) grant such power over them?** Answers will be judged based on plausibility. Specifically, given that demons are probably at least as smart as humans, why would they just have such a vulnerability? I'd prefer a solution involving as little magic as possible, ideally none. [Answer] **Use of their name forces them to be aware of the one truth they can never know.** *TL;DR: If demons seek permanent power but trust no one, they put themselves in a strange position where mathematical truisms paint them into a corner which leaves their soul small and frail holding all the strings. Use of their name suggests you might know how to tug at those strings and unravel them wholesale, from the inside out!* Being a demon is tough work. If you think facing down a 4000lb Glabrezu without their name is difficult, try keeping that much muscle in shape in the gym! Never mind how many manicurists you go through keeping the claws in shape! I don't know how creative such demons truly are, but the easy route towards the perfect French tip that can withstand the rigors of going to the gym and benching ten thousand pounds is magic. Such a demon might learn a manicure spell from the nearby resident succubi. However, such spells are often temporary. No demon worth their salt is going to admit in front of a hero that they need a moment to refresh their mani before they can fight. The hero would just laugh at them. No, if a demon is going to do something, they're going to do it right, and permanently. Not just nice french tips with a clear lacquer over the top, but razor sharp claws that resharpen themselves if they are blunted and can extend or retract at will! In fact, come to think of it, why even go to the gym to maintain one's physique? Why not just cast a magic spell which permanently makes you into the glorious Hanz (or Franz) that the trainer keeps telling you is inside you, just waiting to break free. Just get the spell right once, and think of the savings you could have on gym memberships. Demons that wish to become more powerful, *permanently*, must be careful. If fairy tales have anything to teach is, it's that one of the most dangerous things you can do is wish for something forever, and have it granted. Forever is a very long time, and every spell has its price. The demon is going to have to make sure the price is not greater than the perks. It would be a real waste to have a manicure spell create the perfect claws, only to find that they come with a peculiar perchance to curve towards one's own heart in an attempt to free themselves from the demon that cast them. So we need proofs. We need proofs that each spell is a good idea, before we cast it. Then, once we cast it, we need proof that the spell actually worked intended. Otherwise, who knows if the next spell will layer on top perfectly or not. **Mathematics to the rescue!** The world of First Order Logic (FOL, or herefter simply "logic") is designed to offer these guarantees. With a few strokes of a pen, pencil, or even brush, it can write down a set of symbols which prove, without a shadow of a doubt, that not only will the spell work as intended, but that the side effects are manageable. How? So long as the demon can prove that they can cast a negation spell to undo their previous spell, the permanency can be reverted by the demon. With a few more fancy symbols, the demon can also prove that nobody else outside of the demon can undo their permanency. It's a simple thing for mathematics really. Mathematics has an amazing spell called *reductio ad infinitum* which does unbelievable things. However, there is a catch. There is always a catch with magic, even when that magic is being done through mathematics. In 1931, Kurt Gödel published his [Incompleteness Theorems](https://en.wikipedia.org/wiki/G%C3%B6del's_incompleteness_theorems). These are 3 fascinating works of mathematical art which invoke the true names of First Order Logic and Set Theory. Gödel was able to prove that any system which is powerful enough to prove out all of algebra (1 + 1 = 2, 2 + 1 = 3, 3 \* 5 = 15, etc.), could not prove its own validity. The self referential nature of proving itself crossed a line that First Order Logic simply could not return from. He proved that any system which tries must pick up one of these five traits: * Incomplete - they missed a detail when trying to prove everything * Incorrect - They got everything, but at least one point is wrong * Unprovable - They might be right, but they can never prove it * Intractable - If you're willing to sit down and write down a proof that takes *longer* than eternity, you can prove a lot. Proofs that fit into eternity have limits. * Illogical - Throw logic to the wind, and you can prove anything! If the demon wants *itself* to be able to cancel the spell, his proof is going to have to include his own abilities, creating just the kind of self referential effects needed to invoke Gödel's incompleteness theorems. After a few thousand years, the demon may realize that this is folly. A fascinating solution the demon might choose is to explore the "incomplete" solution to Gödel's challenge. What if the demon permits the spell to change itself *slightly*, but in an unpredictable way. If the demon was a harddrive, perhaps he lets a single byte get changed by the spell in a way he cannot expect. This is actually enough to sidestep Gödel's work, by introducing incompleteness. However, now we have to deal with pesky laws of physic and magics. We can't just create something out of nothing, so if we're going to let the spell change a single byte of us, there must be a single byte of information, its dual, that is unleashed into the world. Trying to break such conservation laws opens up a whole can of worms. Better to let that little bit go free into the world. Well, almost. If you repeat this process a whole bunch of times, layering spells like a Matryoska doll, you're eventually left with a "soul" that is nothing but the leftover bits of your spells that you simply don't know enough about to use. If someone were collecting those bits and pieces, they might have the undoing of your entire self. You can't prove it, of course, but it's possible that those pieces that you sent out into the world have the keys to undo your many layers of armor, and then you *know* they are the bits that can nullify your soul if they get there. So what do you do? You hide them. You cast your spells only on the darkest of nights, deep in a cave where no one can see you. If you need assistants, you make sure to ritualistically slaughter them all, lest one of them know your secret and whisper it to a bundle of reeds, *"The king has horns,"* if you are familiar with the old fairy tale. Make it as hard as possible for the secret to escape, and hope that it withers away to nothingness before someone discovers it, leaving you invincible. Now we come back to the name. The demon is going to have a name it uses to describe its whole self, including all of the layers of spellcraft it has acquired. This will be a great name like *Abraxis, the Unbegotten Father* or "Satan, lord of the underworld." However, they also need to keep track of their smaller self, their soul. Failure to keep track of this might leave them open to an attack if they had missed a detail when casting their spells, and someone uncovered something to destroy them. This would be their true name, potentially something less pompous, like Gaylord Focker or Slartybartfarst. They would never use this name in company. Why draw attention to the only part of them that has the potential to be weak? So when the hero calls out for Slartybartfarst, the demon truly must pay attention. If they know the name the demon has given over the remains of their tattered soul, might they know how to undo the demon entirely? Fear would grip their inner self, like a child, having to once again consider that they might be mortal. Surely they would wish to destroy the hero that spoke the name, but any attempt runs the risk of falling into a trap and exposing a weakness (surely their mind is racing, trying to enumerate all possible weaknesses they have). It is surely better for them to play along with you, once you use their true name, until they understand you well enough to confidently destroy you without destroying themselves. So you ask for answers which are plausible. This one needs no magic at all. None of the rules are invalid in our world today. Granted finding a spell of perfect manicures might be difficult (believe me, some women have spent their whole life searching), but the rules are simply those of math. We can see this math in non-demonic parts of society as well. Consider encryption. An AES-256 key is so hard to brute force that it is currently believed it is impossible to break it without consuming 3/4 of the energy in the Milky Way Galaxy (no joke!). However, know the key, and decryption is easy. Worse, early *implementations* of AES took shortcuts. They actually left the signature of the path they took through the encryption in their accesses to memory. The caches on the CPU were like the reeds from the old fable. Merely observing how long it took to read data was sufficient to gather those reeds, make a flute, and play a song that unveils the encryption key (which is clearly either "The king has horns" or "1-2-3-4-5" depending on how secure you think your luggage combination is). Observing the true inner self of the AES encryption implementations was enough to completely dismantle them. Of course, not every implementation fell victim to this. You had to know the *name* of the implementation to determine which vulnerabilities it had, and how to strike at them. Or, more literally, consider the work of Alfred Whitehead, *Principia Mathematica*. Principia Mathematica was to be a proof that you could prove all of the truths in arithmetic using purely procedural means. In Principia Mathematica, there was no manipulation based on semantics, everything he did was based on syntax -- manipulating the actual symbols on the paper. Gödel's Incompleteness Theorem caught Principia Mathematica by the tail, proving that its own rules were sufficient to demonstrate that it could never accomplish its goals. Principia Mathematica went down as the greatest Tower of Babel of modern mathematical history. Whitehead is no longer remembered for his mathematical work. He actually left the field of mathematics shortly afterwards, and became a philosopher and peace advocate, making a new name for himself there. [Answer] The lecture hall was still and silent as the old man limped towards the waiting chalk boards. One hand was a withered claw, one eye missing and covered by a patch. Conflicting rumours said his limp came from a wooden leg, or an old injury, or something more mysterious. What is certain is that every student there had heard enough to be nervous. In a quiet voice they strained to hear he began speaking. > > "Some say demons are evil. That they destroy, and main, take delight in pain and misery." > > > He turned slowly, scanning the crowd with his one eye, letting the hush fall. > > "Some people are wrong". > > > The clawed hand reached out and pulled a cloth away from the table revealing a glass jar, inside it was a small red humanoid creature. It scowled out at the watching students and bared its teeth at them. > > "This imp, if it could escape the glass we place it in, it would steal. It would murder you in your sleep, it would cause subtle mischief and feel no remorse for its actions". > > > He stops to cough, flecks of blood appearing on his handkerchief before he tucks it away in his pocket. > > "But that does not make it evil, no more than a lion is evil when it eats a man, no more than a sword is evil when it runs a man through. Whether the sword is used as an assassin's weapon, or a bodyguard's, it does not make the sword evil. It is just a tool" > > > "And that is the most important lesson you should learn from me. Demons are tools. They were created long ago, by the ancients. Forged for many purposes, some were messengers, some were even healers, caretakers, cleaners. The ancients created them to serve their needs." > > > "But then the war came, and they created them to be weapons. To be spies and assassins, to be warriors and whatever else they needed. Lamashtu created to pass through the darkness and strike from the shadows, Glabrezu as shock troops and mighty warriors. They were weapons, forged to a purpose". > > > He stops to cough once more, the little imp strikes angrily at the glass. > > "And they were too effective. Both sides died to an onslaught of demons, unable to defend themselves. The old world died in an orgy of blood and violence that left cities and nations shattered. The demons laid waste until in the end the great banishing was wrought and cast them out from the world." > > > "And there in the void they did war upon each other, and only the warlike survived. The peaceful demons, they were the first to die. For you see they had no purpose beyond their Purpose. No demon has purpose beyond their Purpose. They have a goal, whether that be mischief or warfare or simply delivering messages. They have no thought but that goal, and so those who did not think of warfare fell before those who thought of nothing else." > > > "So you may think of demons as evil, but they are not evil. They are far more dangerous than that. They are a Purpose, a goal, a drive. They are that Purpose given flesh and the power to achieve that Purpose by ancient masters of powers far beyond our knowledge. Know a demon's Purpose and you can understand how to work with it, but step in the way of its Purpose and it will cut you down with no other thoughts and no feeling. You can never be friends with a sword, so you can never be friends with a demon." > > > "The only way to be safe with a demon is to know the ancient words of commands, the code that was embedded into each demon when it was created. Know the true name of the demon and you command it as its master. It must obey you and your command will become its new Purpose and it will strive to complete that Purpose with no other thought". > > > He pauses and holds up his disfigured limb. > > "But be careful, always be very careful, for if you get the name wrong then it is not bound to you. It may deceive, it may dissemble, it may pretend, it may lull you into a false sense of security. Never let down your guard, for a True Name binds the Demon to obey you but get the name wrong even slightly and you have nothing but the hope that its purpose is not furthered by injury to you or others." > > > "Even when bound with their true name, be careful with your commands. Bind a demon and command it to allow no-one in the room and it will slay you immediately and then any others who enter. Order one to defend a gateway and even when your body is dust and no memory of you remains it will continue at its task. Order one to kill your enemies and it will hunt until the ground is red with blood as it finds a reason that everyone is an enemy." > > > **TL;DR**: Demons were created as weapons and tools, and each was created with a command word that could be used to over-ride their programming. The True Name is that command word. [Answer] **Fear**. Speaking the True Name of a Demon, tells the Demon two very important things, one you know its name and two you speak the Adamic language. These two things allow you to do something else - speak the True Name in reverse. This has the effect of *unmaking* the Demon, just as the act of (the god of your universe) speaking the Name, created him, as (god) cannot lie. That is why the True Name of a being holds so much power over it. If this answer is considered too magical for your setting, simply have the Demon *believe* that will happen, rather than it actually being the case. [Answer] The concept of a True Name is old - Real Old. Perhaps looking at the origins of the concept will provide some inspiration for how you would like to use it. **What has come before** In Egyptian mythology - Ra told Isis his true name after being bitten by a poisonous serpent, which she used to heal him. However, the knowledge of his true name granted her power equal to his. For this reason, the Egyptian Book of The Dead lists the true names of beings one can expect to encounter in death - as a means of exerting control over them. In Judaism - The true name of God is thought to have immense power, such that anyone who speaks it would then hold power over God's creations. This concept is central to practice of Kabbalah. In Christianity - It first appears in the Old Testament when God names and thus creates Heaven, Earth and the Seas and again when God commands Adam to name the animals, subjecting the animals to Adam's control. The bible has several more examples of the power of names, such as when Jacob wrestles with the angel (Genesis/Hosea) who refuses to tell Jacob his name, even after defeat. In some Aboriginal Australian communities a person's name is viewed as so important, it is considered to be a body part. When someone dies their name becomes taboo, so much so that those with the same name still living will adopt a new one. Some Inuit tribes hold the belief that man consists of three elements - body, soul and name. The theme appears again and again in folklore - The German story Rumpelstiltskin, the Norwegian story of Saint Olaf, the Scandinavian version of Earl Brand This belief is so ubiquitous that many cultures throughout history had the practice of a public name and a private name. The Romans, The Egyptians, The Celts, even some Native American tribes all used multiple names to ward off harm. The Romans went so far as to allow slaves no legal name, preventing them from being a legal person - reduced to property. Even today's common proverbs such as "speak of the Devil and he shall appear" and "If you speak of the Devil, you step on his tail" reference this old thought process. The list of authors who have used true naming within their works is long, it notably includes J.R.R Tolkien and Ursula K. Le Guin. **Possibilities** So, now that we have an understanding of its historical use and how it has come to hold such a pervasive position in the collective mind of humanity - what are likely explanations for this power? *Divine Pronouncement* - It is that way in your world because the deity in charge has deemed it to be. This is probably the 'magical' answer you aren't wanting. *Legal Agreement* - From the information you have provided, we do not know the origin of your Demons. Perhaps in exchange for access to arcane, physical or monetary power they agree to certain terms, one of which relates to either keeping their name as signed upon their contract for power a secret. Alternatively, it could be written into their contract that in exchange for access to such power, they agree to serve the one in possession of their name as signed on the contract. There are endless variations on this theme which can be as strict or permissive as you choose. *Geis* - In Irish mythology, a geis is a curse (sometimes a gift) which places the receiver under obligation - which if not followed through promises pain, damage, dishonour or even death. It could be that when your demons are created, they are placed under such an obligation to their creator - who should in theory be the only one who knows their true name. Should anyone else find out this true name, they can subvert the obligation to their own use. *Legal Status* - Depending on the laws of society in your world or the world of the demons, perhaps this name confers upon them a legal status with laws they are legally obliged to follow. Perhaps their name includes a prefix or suffix which denotes them as a lesser caste/class or slave. the speaking of their name doesn't magically compel them to do anything - but perhaps highlight their status and the laws that surround their behaviour with those of a higher class. maybe some demons always follow these laws and some of them avoid them when they can but feel pressed to comply when their name (and status) are revealed. *I would be really interested to see what could be done with the "name as a body part" concept, however I can't think of anything non-magicky do so with it.* [Answer] Demons and angels are constructs, essentially: they're created to perform one or more tasks; usually one, very specific task. They are tools of the gods, or at least some more able being. This is the traditional meaning of the terms even in our world - consider Maxwell's demon. It was once thought that rather than gravity, things rose and fell, whether raindrops or rivers or waves, because angels bore them. If you fell, an angel bore you safely to the ground - or dashed you down for your foolishness. The simpler angels and demons were not sentient; only those closest to the right hand of their creator. The demon name is what you use to address the demon. A powerful enough spellcaster or god can, having this information, cause the demon to sleep, to die, or give it various other standard commands. They can only do this right to the demon's face, though; it can be done remotely, but only by having some way to speak to the demon from a distance (a telephone, for example, or having a proxy speak for you). Consider the comparable example of the unix daemon, where knowing the process id (aka pid, aka name) allows you to make the daemon sleep, or die, or send it various other signals... if you have enough power. You have to do it from the commandline of the machine on which the demon runs; you have to tell it to its face. You can do it remotely, but only by first finding a way to remotely send commands to the machine's commandline, perhaps via a proxy. Essentially, the name is just a form of addressing, and allows control, though not usually from a distance. Some unix daemons will accept *some* commands from non-empowered users. Some daemons will even let regular people kill them. Others are super-secure, and will not even speak with anyone other than god. Some ("root kits") are even undetectable. Trying to find out their name/pid will not list it; sometimes, their name cannot even be said. Knowing their name will be useless for most commands because the commands themselves have built in protections against using them to control the root-kitted daemon. To affect such daemons, you have to go to a lower level, to write your own incantations that work closer to the core of reality than the normal commands that less skilled practitioners use. --- Consider a daemon created for delivering mail, with the public name "SMiTePa" and the private name "9d4f712". So, the work the demon does, is public. Anyone in the world, knowing its public name, may be able to use the service it provides; they write a letter, then burn it in their fireplace while saying "SMiTePa, Helo, please send this to john at the fishing net," and because this is the task for which the gods created the demon, and the correct incantation, then it will do this for them. If you are local to the demon, and are recognized as one of its managers, you can give it other commands; change who it will accept envelopes from, for example. But if you know the True Name of the daemon, and you are close enough to use it, and you have enough power, then you can do more, even if you are not one of its managers. You can make it give you a copy of each message, or you can even replace the demon with one of your own that delivers beer instead of envelopes. --- I would draw a distinction between this and, say, the word of power used in historical golems, or an override code in an android. These are somewhat analogous, but are essentially just commands which grant privilege, included for safety's sake. The PID, like a demon's True Name, is much more than that; it is tied up with the identity of the daemon, and is part of how "being a daemon" works. For a human, everything that defines what it is to be you, your "self", is located in your body (where the seat of the soul or spirit is, whether they even exist, etc is debatable, but that the self is in your body is the general consensus). For a daemon, its essence -- the compiled source code of its being, which governs what it is and what it can do -- is "elsewhere". The "True Name" (or the pid, in the case of the unix daemon) is the addressing scheme which grants a connection to that body, to pass it commands at the level of its creator (the kernel, pid 0 in unix). This is why you don't use the True Name of God. Sending random stuff to pid 0 is never a good idea. [Does this make pid 1 ("init") a daemon, or a prophet? It is the all-parent, the parent of zombies and of ghosts, it is the reaper of children. In the normal nature of things, it is immortal, living as long as pid 0, protected from SIGKILL. But it *can* be slain, as we can see when the demon takes form in PS-Doom.] [Answer] **Immediate submission based on a tendency to obey a chain of command.** Consider the following: The cultures of demons are such that names are very secretive and known only by entities with higher authority, and that knowing them will cause very submissive reactions in the demon. Demons are not mortal and are known in stories to live for thousands and thousands of years. They've been subject to a hierarchy and have yielded to a chain of command for that length of time, and suddenly they've just met someone who knows their name. Only those higher on the hierarchy (the rulers of the lower domain/upper domain) have such power and authority, and who would they be to risk their neck rejecting your authority? It could also be that it's a contractual and supernatural obligation regardless of the demon's will, because the secret name is like a key bound to the demon, and the authoritative power comes from whatever higher authority that created that demon's name or existence. Punishment for these entities goes far beyond any of our imaginations, so they have a very strong cultural case for yielding to those that know and can speak their name. [Answer] It's actually just a matter of childhood conditioning - yes, even demons were once small little pups (even if only briefly). Speaking the demons True Name is the human equivalent of having your mom or dad call you by your full name - middle name included. The demon cannot help but think, "Oh crap, I'm trouble - you must know my parents!" Even a world-eater fears being told on, and if you know their true secret name then you might know their parents - so they will do anything you want, so long as you don't tell on them. :) [Answer] In ancient times, people were named according to their abilities and qualities. For example, take the name Israel. It means: the one who wrestles with God. This trend was prevalent in all ancient cultures such as Arabs, Chinese, Indians, Mayans, Babylonians and Incas. Hence knowing someone's name would imply that you are aware of their true identity, strengths and weaknesses. That is why Jacob A.S. asked the name of the person who beat him in wrestling, but the stranger (it is stated, He was God) refused to tell. And that is why when you know the name of a demon, you gain authority over it (as it implies you are aware of its identity, history and abilities) provided that the demon does not know your name. [Answer] A Name signifies individuality, a singling out of a person with all of his/her specifications. Just as we bind out contracts by names (signatures/individual word of honor) so are Demons consigned by their individuality. When (enter name of deity here) created the universe it was by words, turning chaos into order by setting individuality and codes to things and attributes. However, the chaos remained and would not be entirely contained. So the deity individualized chaos into personified beings - demons, with awesome powers of destruction and mayhem and general chaos-making. This was done with the same method of control - naming and individualizing stuff to make them more ordered. The deity set the limit of chaos that these beings were capable of at the use of their name, hard coded into their DNA to offset madness and set in order and control. In short, god was all: "Let's rein in the crazies". At the time, everybody was speaking Ademic (everybody = two people) so this was a sure way to stop demons from running amok. Alternatively you can replace "name of deity" with "Dungeon master" - If you don't set specifics to things in your story, people have to guess or role everything = chaos. Or "Software engineer" - If you can call a variable/array but it's name, cool. If the variable isn't set right, it can wreck your code/world. A question of the significance of names; a pretty neat one, for world-builders :-) [Answer] **TL;DR: Divine power** This is the "official" answer according to Hebrew lore (not *really* the Bible though, so this is not theology), albeit grossly oversimplified. First, Jewish culture believes in the power of names. A name is not just a sound, it is inextricably linked to the character of the thing named. This is reflected on uncounted places in the Bible, such as when Jesus tells his disciples to "go and heal in my name"; he is telling them to go heal people and in doing so reveal his character. Further, naming something is equivalent to asserting ownership over it, which is why Adam gets to name all the beasts of the Earth at the beginning of Genesis and then after being driven out of paradise names his wife (where previously they were co-equal), asserting his dominance. Second, the power of the Word of God is unlimited. Remember that in the creation story, the entire universe started existing *because God said so*. Using the mythical language of Adamic (which is non-Biblical, by the way), speaking the True Name in the language God uses would have some of that power. Thus, just knowing the name is power, and being able to speak it in God's language has all kinds of scary ramifications. [Answer] In short: maybe they're like dogs. In prehistoric times, the wild demons were domesticated by some powerful fantasy race. Apparently, it was beneficial for both races, and for many millenia, the demons were breed to be more and more loyal. Then, for some reason, the other race have left the earth - maybe they were wiped out in a war, maybe they moved to another planet, whatever. But some of them have left their demon pets here. Lamashtu have only learnt to hunt the weakest of mammals, and constantly travels seeking for more food. Glabrezu is so bored, it plays witty games with its chew toys. Nabassu still guards the place it remembers as home, scaring away pesky two-legged vermins. But if any demon hears the name it was called ages ago, the old instincts (and, probably, a bit of insanity) kick in. The demon has been waiting for so long, it doesn't care how the boss looks like, the only thing that matters is that the boss is finally back, and everything will be like in the good old times again. [Answer] In my work, I tend to treat demons, angels, and similar spirits as the manifestation of an idea or concept. For example, in a particularly dark world I developed, a horde of demons sprang from the mind of a goddess as her fears and worries for humanity manifested themselves. Parallel to this, we already have the concept of conquering our detractors; e.g., conquer your fear. Combining these two, let a particular demon named Aibohporca represent the fear of heights. If you learn the name of Aibohporca, you can then conquer it and, similarly, conquer your fear of heights. This can be extrapolated to any idea or concept, positive or negative. For example, learning Cupid's real name would give you command over love. [Answer] "Demons" are trespassers from another place/plane, literally. Knowing the true name of a demon means that you can identify him, and cause him all sorts of legal trouble, should your soul/conciousness ever get to the other plane (e.g. by dying at the hands of a demon). --- Whoever Created Demons put a voice-activated limiter into them (if you want to have a nice religious tie-in: Only Humans can make use of those limiters, because we were created in the image of god (we share a voice modulation with god). [Answer] the underworld has yet to start using social security numbers, and demons don't have mothers (or at least their mothers don't have maiden names). also, they don't really know when the exact date they were spawned since the earth wasn't really revolving around the sun yet. in fact, the only security question on the demon's retirement account is his name. so, if you know his name, you can steal his identity. this would be a major problem since it would give you all his powers. plus, you could steal the pension that he has been working towards for 50 million years. and he really wants to toss it all in and relax next to a nice little lake of fire. [Answer] This answer doesn't really depend on "magic", but on the idea that the universe in which your story unfolds is somewhat similar to a simulation. However, it does not require that the fact that demons can be controlled by knowing their True Name is a purposeful, conscious decision by the creators of the simulation, so I don't consider it a "because [the gods] said so" explanation. # Setting The ur-language could be the [instruction set](https://en.wikipedia.org/wiki/Instruction_set) of the simulation. In this simulation, entities interact by sending messages to each other and to The Simulation itself. For instance, to lift a bucket, a person's 'handle' in the simulation would inform The Simulation that a force of, say, 1 N should be applied to the 'handle' of the bucket, in a 90 degrees angle to the ground. We can represent this with the following ASCII-art: `<Person> --[apply-force: 1 N, surface-angle: 90 degrees]--> <Bucket>` # The source of the demons' power Demons, or really any supernatural element in the simulation, are entities which figured out a way to install [proxies](https://en.wikipedia.org/wiki/Proxy_pattern) in their interaction with others. The demon can check which messages are sent to its proxy, and modify the message before it is sent to itself. When a person interacts with your Glabrezu, instead of this happening: `<Person> --[push-over]--> <Demon>`, this happens: `<Person> --[push-over]--> <Demon-proxy> --[do-nothing-in-particular]--> <Demon>` This way, all the supernatural things you describe are possible: the proxy can report the Lamashtu is not visible when in fact it should be; it can claim to have arbitrary amounts of energy available, thereby being able to reach arbitrary speeds up to the speed of light (sorry, darkness); absurdly large Glabrezus' proxies can claim the Glabrezu has a dexterity it should never possess, etc. # True Names as a way to subvert that power True Names, now, are references to the true identity. By knowing a demon's True Name, a person can bypass the proxy: `<Person> ----> <Demon-proxy> ----> <Demon> '----[push-him-over-anyway]----^` With the proxy bypassed, all 'supernatural powers' of the demon are out of the picture, and the demons have to face the harsh reality that their physique is rather unfit for real life. At this point, even a child could force them into submission. [Answer] It's the private key that enables software update signing.... To the code that runs in their brain. Most orders or requests are accepted or validated based on their normal rules and logic. With the true name, you can literally change their mind entirely - but most wizards don't really understand the code, so tend to have a bunch of hacks for the most common sorts of things. [Answer] because 1. you get your name from your parents 2. you are expected to obey your parents absolutely these are ancient traditions in nearly every culture for obvious reasons. in fact, many cultures consider children to be little more than property of their parents until they take a new name (e.g. during a rite of passage where a boy becomes a man, or when ownership of a woman is transferred during marriage). so, by naming the demon, you are assuming the role of it's parent, and therefore it must obey you (by divine law/natural order/etc.). also, it is worth noting that strangers are universally feared. and a stranger is loosely defined as someone who's name you do not know. e.g.: > > suzie smith: mommy says i'm not supposed to talk to strangers > > > creepy bloke: oh, right. i'm john, and you're suzie, right? there, now we're not strangers! > > > this fear of strangers is ancient and deep-set for good reason. before strong central governments evolved, theft was controlled by a social network that would punish people in the community who stole/vandalized/raped/killed/etc. since this network had little control over people who were about to leave the community, it was assumed that anyone who did leave the community had done something too horrible to accept the consequences. even if the stranger arriving in your community had not yet committed a crime, they were much more likely to leave again. this transience meant you could not punish them if they committed a crime. this lack of control over vagrants made them scary. the upshot of this reasoning has historically (pre-1500's) been rampant strangercide. more recently, it has been a less drastic mistreatment of vagrants by nearly all centralized authorities (just try getting a state id without a permanent address). on a more personal level, it has left most people with the (frequently wrong) impression that strangers are more dangerous than people they know. [Answer] A True Name contains within it a description of how a creature works--and thus inherently describes a creature's defenses and provides an awareness of what it's doing. If you know a creature's True Name you know how to bypass those defenses. No matter how strong the creature there's a chink in it's defenses somewhere--and you know it. If he tries to attack you you'll know it and will be able to strike first--killing him. If you choose to attack you'll kill him. Basic self-preservation means it will comply with your instructions because you can kill it and you'll know if it isn't complying. [Answer] For True Names to work the way that they are described in mythology you will need a framework that, for all intents and purposes, *is* magic. We can discuss numerous pseudo-scientific possibilities, but ultimately to the Namer and the Named it might be the same thing. Take for example Strata by Terry Pratchett. The demons of that story are artificial constructs controlled by the computer which manages the disc world, and as such are susceptible to control by the nature of their programming. In such a setting anyone who learns the correct access code - the True Name - can issue commands that the construct-demon is required to follow... albeit with the standard caveats about *how* they follow their instructions. From the perspective of someone who doesn't have any knowledge of the controlling computer or that the demons are in fact constructs controlled by that computer, the result is indistinguishable from magic. Which is all very fine in that story where there's an obvious reason for this to be the case. It's a little tougher to explain something like this in any world that we can honestly say is close to what we know of reality. The "True Name as command sequence" concept is related to the "Magic is Science" trope. Generally they involve some sort of technology that is controlled by spells which are simply the commands in the control language. In Cyber Way by ADF the mystical power turns out to be an alien computer that is controlled by incantations in Navajo. In the Well World books the computers are built into the crusts of planets and controlled by will power by anyone with the ability to interface to them. Stargate has its Ancients and their toys that respond to mental commands. And the list goes on. Any sufficiently advanced technology, eh? Without invoking magic - or a technological substitute for magic - the remaining option is psychology. What would cause a Demon to respond to a True Name as if it were binding on them? Perhaps True Names are simply implanted hypnotic triggers that force a conditioned creature to accept your commands. Maybe Demons have all been conditioned so that they can be controlled by someone if they ever get out of hand. Maybe the Demons are given such conditioning as an entry or exit requirement when they traveled from their home to ours. Perhaps this is standard practice at the inter-universe border stations, or a condition of their release from their home. Maybe they have a more prosaic technical reason: implanted devices that are activated by the right series of sounds. Let them believe - right or wrong - that they have a sound-activated bomb in their heads that will go off if they fail to follow commands given after the activation of the device and most will simply follow the restrictions rather than die. And of course there's always the chance that they really are AIs with back doors into their command processors. Or is that too much like "Magic IS Science"? [Answer] Let's start by understanding where the idea that demon's can be controlled by knowing their name comes from. Other answers highlite that many cultures throughout history separate considered a name to have power. That raises the question about the experience that make people believe that names have power. From a modern perspective rituals that are about summoning demons are similar to what's done in Family Systems Therapy and Systemic Therapy. Part of Systemic Therapy is it to address parts with their name. A name binds a concept in a way that makes it easier to address the concept in a systemic constellations. The [Focusing](http://www.focusing.org/sixsteps.html) framework of Eugine Gendlin with has 80 scientific papers in it's favor also has finding a name (a handle) as an essential part to talk to an internal part. There are mental processes that happen when a mental concept is given a handle. Processes that make it easier to influence those concepts. Many other psychological interventions use finding names as part of their process. Historically a daemon is usually an entity that's tasked that's brought to consciousness and then get's tasked with doing something in the background. That's the point of most magick rituals summoning daemons. That usage of the word daemon is strong enough that your computer runs daemons in the background. If you want to shut down daemons in your computer than you need the name of the daemon to do so. In Linux of you know it's name is `John` you can simply write `sudo killall John` on the command line and the daemon is killed. Depending on how daemons work in your world they could work similar to computer programs with can get a physical form when summoned into this world. [Answer] Demons are not just physical beings, but also metaphysical beings as well. They aren't just objects taking up physical space. They are concepts occupying metaphysical space. And by manipulating the metaphysical space you can CHANGE them. Having access to their True name gives you access to their metaphysical space and the power to alter it. Like the key to a safe. This is terrifying to them. Their physical presence is tied to the metaphysical realm that changing one can change the other. Though physical changes can be reversed, changes to their essence could make them something/someone else entirely. Like a permanent hypnotist. Of course most demons true name won't be something as simple as [Bob](http://data:image/jpeg;base64,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), or even [Gozer the Destroyer](http://ghostbusters.wikia.com/wiki/Gozer). Those are nicknames like '[He-who-must-not-be-named](https://en.wikipedia.org/wiki/Lord_Voldemort)'. Alternate labels to help pinpoint one vs. another. Though should a demon come to be well known by such a label for long enough, it will start to hold some power over him as well. [Answer] Demons that interact with living humans are breaking the rules. If you know their true name, you can rat on them when you die. This is a similar situation to if you had evidence of a kingpin's guilt, but, whereas a kingpin can just kill you to stop you from telling the authorities, that wont work for a demon, since you can only tell their authorities after you die anyway. It's textbook blackmail. [Answer] Because the name of something IS that thing. Here are a few demonstrations of this principle: Automobile: self-moving. Luggage: something you lug around (not “belongings”). Party: separate, apart, partial (hence “apartment”), i.e. “not everyone is invited.” Exclusive, etc. Universe: one axis (rotation). Sex: gender. Author: an authority on something. Allah: the God. Novel: new. Mystic: initiate, beginning. The Rolling Stones: Rock & Roll. Professor: one who professes. President: who presides over (Congress). Psychopath: illness of mind. Telephone: speech across distance. Movie: because it moves. Spirit: to breathe. Virtue: manliness (like the Pali *vīrya*). The name of something (the word) always tells you the real, de facto meaning of what something is: Feminism: religion of women. Men's Rights Activist: fighting for the rights of oppressed men. There are no Female Right's Activists and Masculinists, see? It's all in the word, literally, the true, de facto meaning of something. Literally: in terms of the word (letter). So returning to your question, I suppose it's powerful because the name of something is the essence of that thing. In Islam it's said that God is unknowable apart from His Names and Attributes. Meaning that if we did not have Ar-Rahman (the Most Compassionate) and Ar-Rahim (the Most Merciful), we would not be able to know what God is. What is God besides Compassion? “Grant us good things, both in this life and in the hereafter. To You alone we turn. He replied, As for My punishment, I smite with it anyone I will. But My mercy encompasses all things.” (The Qur’an 7.156) So since God's Ninety Nine Names are the most powerful attributes (the Holy, the Knowing, the Restorer, the Destroyer, etc.). God (Allah, lit. The Deity) is the most powerful thing in the universe. Of course, theologically, we say that apart from those names it's impossible to know the essence of God, but given His most prominent Names (the Most Compassionate, the Most Merciful), we have an understanding what He is. Food for thought. Mu’min: the secure, the safe. Kafir: the one who conceals (hides, covers up). *Bismillahir Rahmanir Raheem* is the standard formula: in the Name of God, the Most Compassionate, the Most Merciful. “Say: "Call upon Allah, or call upon Rahman: by whatever name ye call upon Him, (it is well): for to Him belong the Most Beautiful Names.” (The Qur’an 17.110) Incidentally that Qur’anic expression almost sounds like an expression of the trinity: In the Name of God, the Most Gracious (Beneficent, Compassionate), the Most Merciful. In the Name of the Father, the Son, and the Holy Spirit. [Answer] Naming is often at the heart of creation myths. Gods name things in order to create them. This guy does a thorough job of spelling that out here, but his first example is crystal. "Let there be light." And then there was light. The light is named and then it's created. [The Power of Names: In Culture and in Mathematics](https://amphilsoc.org/sites/default/files/proceedings/1570204Graham.pdf) I've always taken the true name concept to be tied to this idea. If you know the true name of something, you know the name the divine spoke to create it. With that name comes the knowledge or power any creator of a thing would have over it's creation. That's pretty much root access level to a piece of creation or a soul/spirit in the Demon's case. Furthermore, in the case of demons, there's often a turning away from the natural order of things that twists them somehow. If you know the true name of the demon, you know it as it was before it was turned. The pain and inner turmoil of being reminded of it's true self, the being as it as just after creation before it rejected its own role in the natural order has all kinds of implications you could tie into a set of laws for a speculative setting. You want a mess with a demon? Remind it of what it used to be. The ex-angels in particular really hate that. [Answer] Maybe demons are as smarts as AI because they function like AI. They may be very smart but are designed in a more simple way than human (only pure evil and power, no need for philosophy and all this complex "useless" stuff). As they have a very formatted mind they completely lack common sense (that is why you can't turn good a demon for example), so there is rules for them to decide what they should do. Most of the time if someone give them an order, they will disobey, because they are evil nasty guys, so the one who created them made it so they will obey when he will call them by their names. So when a demon hear his true name, an inner mechanism triggers and makes them simply unable to disobey. Demon are aware of that but they never managed to remove it. Moreover if they look too obviously for a way to remove this mechanism, the one who created them could become angry, so these attempts are very rare. [Answer] In many magic philosophies, to know the name of a thing, you gain control of the thing. This can apply to inanimate objects, people, animals, plants, and the supernatural. Most tales with someone controlling a supernatural creature (by name, or otherwise) generally fall along the same path as the Monkey's Paw tale with its moral of "Be careful what you wish for". In D&D (which your question seems to reference), knowing a demon's name allows you to attempt to summon it, but the name must be used properly as part of the correct ceremony or spell, which can generally only be done by higher level characters. [Answer] Demons used to be good people before they became, well, demons. Many are fallen angels. They are made to forget their names so that they forget their goodness. If you utter a Demon's true name, it will remember its former life and goodness, and will stop hurting you, feeling grief at its evilness. [Answer] A couple thoughts: In the Bible's Old Testament, the name of God was abbreviated and not even fully written out for fear and reverence of it. In the New Testament, followers of Jesus preach that "there is no other name by which we can be saved". Also, in Revelation, Jesus promises to give to anyone who overcomes a secret name known only to that person and Jesus. I take these meanings to be related to the fact that a name is an expression of a person's character and nature. This includes their power but also *who they are*. I am not an expert but I can imagine people invoking the names of gods and demons that they follow in order to gain their power. Unfortunately, that may mean also gaining some of their other character traits... I would guess that the turning of the name into a secret key to command that power is a later invention. It seems less likely to me that an ancient man would believe he could command supernatural forces with a secret password than a modern man believing it. To the ancient world, spirits and demons were explanations of the caprice of the universe, and I do not think most people believed they could be coerced except by the help of a stronger supernatural power. But I could be wrong. I suppose there were witch doctors then as today. But I wonder if (then and today), they see themselves as *controlling* or *invoking* a power. My guess is the latter. Again, could be wrong. Another aspect of the use of a name as a key to command is related to the name as a representation of someone. In my mentioned example from Revelation, I believe this refers to the relational intimacy of having something good within oneself that is a secret between one and God. When someone else knows who you truly are, that creates intimacy and vulnerability. And vulnerability is something that can be exploited, if trying to exploit things for power is your deal. So, perhaps knowing something's true name is intimately knowing it so that you can exploit that intimacy to exert power over it and control it. I might add that that sort of plan doesn't tend to win friends or influence people in the long run. Unless, I suppose, you're Ender Wiggin. [Answer] We may only survive these creatures through wisdom, knowledge and education. This is how the higher being designed our culture. Our sins are judged and our virtues will save us, therefore we must further educate our children. The feared demons are like trials, testing our knowledge, taking out failures, strengthening evolution by this quirk of nature. We need physics to enforce our homes, medicine to cure our sicknesses, and folklore or religion to withstand mystical beings. Encounters with these demons are extremely rare, and few are left to tell the tale, thus only those given proper education and having faith to learn the true names are spared. Good and evil may be in the same team after all, one welcoming with salvation while the other one herding by fear. [Answer] # The Model If you consider the universe (including the realm which demons inhabit) as a kind of computer, then everything in it is a kind of program/data. The common name for a thing is like a reference to an object in a programming language which has a particular type, but the type has an interface which only allows you to interact with the object according to the normal rules of the universe. For instance, I might see an object called "Bob's CD Collection", and it has type FileStream. I can do file-streamy things to this object because that is what this name allows me to do. I can read it, sort it, maybe even add something to it. But I can't convert it into a dinosaur, because that isn't file-streamy. Now, suppose that some entities in the universe are not bound to the rules of the type system imposed on it, which gives rise to the order and physical laws which the universe normally obeys. They essentially have the power to treat any object as any type, and therefore perform any conceivable action in this universe. But, in order to do so, they need an absolute address for the object in question. Normally, the name for a thing is a common name given by ordinary agents within the universe, and interacting with an object implicitly uses its common name. In fact, an object may have many common names, and each of these reflect the interfaces available for the object. One can even "cast" an object to a different type simply by attempting to use it as such. For instance, an object might normally have the name "wrench", and it can be used to turn things. But by swinging it at a nail, you can call it by the name "hammer", and drive nails into other objects. But if you try to call it by the name "fruit" and take a bite out of it, you'll just break your teeth, because that is not one of its names, and you have no power to interact with it that way. # Magicians In this model, a magician is just a hacker who can break the rules because they can cast an object to a type it cannot normally take. Or, to put it another way, it can give a name to an object that it normally doesn't have. Even so, there are limits to this hacking defined by the similarity of the names applied. We could even say that demons are such hackers, and they are more powerful than mere mortals because they know these hidden names of objects and can thus manipulate the world in ways which are not obvious or cannot even be known by lesser beings. They are the Hidden API of the universe, left like easter eggs by the Creator to be found by sufficiently clever individuals, or those who have been given the special sight to see and know such names of things. # Demonslayers But the one power which is greater than using a hidden name is to know the absolute location of an entity within the universe. In programming terms, this would be its physical memory address. This is not just an alias or a reference, but rather its True Name. Having access to the True Name allows such a person to perform any actions whatsoever on said entity. So, it is not really a power over demons, per se. It is a power over anything in the universe. But maybe one who learns such a power does not have the ability to obtain the True Name of just anything. Perhaps there is a cost involved, and Demonslayers can really afford to only obtain the True Name of one or a few things. In this case, the best use of this power would be to control a demon, for they are the ones with seemingly unlimited power (though, in reality, they are limited to whatever hidden names they know or can see). # Conclusion So, although there is a kind of magic in this universe, it is a mostly logical, consistent magic, which is really what you want in the end, right? Programming is all about naming things, and in, in many respects, is the fundamental operation of software engineering. As long as you view the universe as a giant computer, the concept of naming and knowing names as Power is very natural. ]
[Question] [ The internet is a mesh or "net" of computers, all constantly establishing and re-establishing connections with each other. For this reason, only temporarily do servers go down, before they are back up and running again (i.e. "This server is temporarily unavailable. Try reloading in a few minutes"). > > The [Internet](https://en.wikipedia.org/wiki/Internet) is the global system of interconnected computer networks that use the Internet protocol suite (TCP/IP) to link billions of devices worldwide. > > > The internet consists of a vast number of hosting devices. What I am looking for in an answer is complete and utter eradication of the internet so that no information remains or can be salvaged. **How do I take down such a hugely integrated and widespread communications network?** *I do not wish to knock out the power grid by EMP-ing the entire surface of the planet, I only wish to knock out the internet, other devices may still function after the destruction of the network* **Edit:** I would rather the infrastructure to remain, as opposed to destroying all of the associated communications networks. I would like this to be something a non-superpower country could accomplish with the current standings of North Korea, for example as a backlash to security threats. *If it is only possible through strategic bombings or other infrastructure destruction, feel free to include it as well.* [Answer] The distributed nature of the internet makes it really impossible to destroy all of it, and all the information on it, without destroying every computer as well, which you seem to be excluding. To erase all access everywhere you must contact every computer on the internet. In particular I need to ask what you define as 'the internet'. You have a rough hierarchy of computers connected, how many interconnected computers is 'the internet'. Is an intranet at a large company still 'the internet'? What about an intranet of a small company all within one building? My connecting my three computers at my house into a tiny intranet? Is an internet that can connect to all clients hosted by my local ISP only, but not make the 'hop' to a higher ISP (meaning can't reach beyond my city) count as internet? Depending on how loose your definition of internet is it can be nearly impossible to take out the internet (I plugged my cellphone into my laptop. That's two computers communicating, it's the internet!) I don't believe any of the posted answers so far are viable ways to take out, or even more than mildly inconvenience the internet, but that isn't the answer's fault, it's nearly an impossible challenge without an apocalypse that destroys all physical computers. However, there are a few approaches that I can see which you could use to varying degrees, depending on how much you need to actually destroy the internet for your story: **Remove access to large portions of the internet easily** *note, this solution also removes phone, cable TV, and most other forms of electronic communication in addition to internet* It's not that hard to isolate parts of the world from large parts of the internet. Right now data going between continents travels through a few dozen wires spanning the ocean. Not only is the number of lines relatively small, they are completely unsupervised, you can mess with them without anyone seeing you. Cutting a cable is not entirely trivial, but also hardly impossible. You would need something capable of diving deep enough into the ocean to get to the cables, with sufficient cutting power to cut through cable and the protective encasing. This is more expensive then a regular individual can manage, but even a small nation can probably get together enough money to get a cable-cutting sub built. If you don't want to destroy the infrastructure, tricks to disable the communication without fully cutting the wire surely can be made easily enough once you reach it. People could repair these connections, but as long as you have a cable cutting sub you can cut new connections as fast as they can be repaired; it's nearly impossible to watch *all* of line from the US to Europe at one time, it's just too long to properly watch for malicious attacks against it. Imagine Australia if the internet lines to it were cut. Most hosting for large companies and services are located out of Australia, they would lose their Amazon and Wikipedia and many other major sites they use regularly. They would still be able to communicate with anyone in their home continent, and in fact many major businesses may have servers in Australia for latency reasons that would still work, but the internet would be a fraction of what it used to be. For all intents and purposes Australia will be missing most of the power of the Internet. Other places will do better. The US has the most internet infrastructure of any other nation, so many of the big names will have servers within the US. Anyone in Europe will have access to any server on any landmass connected to Europe, which is the majority of all land, so they likely will also not suffer as much; However, both the Americas and Europe/Africa would suffer from lack of connection to the other major land mass. The UK and Japan, two first world nations who make huge contributions to the internet in general, will suffer significantly since their small size means relatively small number of major services have servers within their nation. People within these nations would still be able to use satellite internet, but considering the small number of satellite and the huge number of people there would be significant bandwidth issues, to the point of making the internet effectively destroyed until the countries figure out a way to regulate limited satellite bandwidth in some manner. In theory a country could also try to take out satellite as well. This is harder then taking out the physical lines, but not entirely impossible. **Take out HTTPS** This probably isn't what you want, but removing security from the internet will significantly weaken its usefulness, if not destroy all of it. Right now our secure internet is dependent on two things: 1. No algorithm can decode keys as efficiently as we can encode them 2. We trust our top level Certificate Authorities If either of these presumptions were proven invalid security falls apart. Suddenly with minimal effort one can set up a man-in-the-middle attack and get all my banking information, taking my money over night. They can also inject misinformation or viruses into any request I make online, since they can simply replace messages with whatever they want me to see. This would not destroy the internet, but it could have horrible repercussions. Getting access to the private key of just one CA would allow quite a bit of evil, but publishing an algorithm that allows decrypting of a message using only the public key would truly break security since all CA are equally invalidated at once. The internet knowledge still exists with this approach of course, it's a limited solution to what you want at best. Edit: I added this option, knowing it's quite different then your stated goals. However, I think that, while not breaking the internet, this has room to have a significant affect on internet, economy, and more. I've asked a question inspired by the idea just now, perhaps it will give some ideas of how much harm something like this could lead to: [How can a small country exploit breaking HTTPS to destory a larger country while growing its own strength?](https://worldbuilding.stackexchange.com/questions/31770/most-effective-terrorism-to-someone-that-breaks-https-encryption) **Big bad scary virus** The other option to get closer to what you want is a virus. Of course I don't consider it at all realistic that a virus would *actually* be able to take down the internet, but you get some poetic license here. If you truly want all the internet to go away I suggest using a hand wave virus without explaining exact details and ask your readers to give you some suspension of disbelief; because any answer that does what you want is going to require quite a lot of it. Ultimately it's better to give an answer where you don't explain some details than to try to explain everything and, in so doing, make it obvious to informed readers just how improbable your suggestion really is. There are some things you can do to make the virus idea more believable, to at least get a little leeway from readers. Imply that someone utilized some 0 day exploit (i.e. found a bug no one knows about and exploited it before anyone knew it existed to defend against it) in the very infrastructure of systems that meant that you could spread a dangerous 'virus' in such a way that anyone trying to connect to different services will likely contract it. Basically, someone found a huge security hole that nobody realized was there and exploited it to make an uber-virus before anyone could defend against it. Usually, protecting against a virus after it's released isn't that hard - people will find ways of blocking it and spread that information - but they spread it with the internet. Thus, if a virus *did* worm its way out there and knock out the internet in one go, the method for identifying its root cause, creating protective measures, and spreading them to others would be greatly limited. The virus could also be destructive (for instance, permanently removing data from infected systems to render the information inaccessible). I would go on to say that the virus was subtle in the manner it was crafted. Someone released the virus a while ago and gave it time to spread and infect most ISPs before activating it. In fact say they also infected the certificate authorities and got hold of their private keys. It can now do a perfect man in the middle attack, getting through SSL security by pretending to be your security authority. Whenever you attempt to hit a website it can instead send its own virus back to your computer to spread further. Suddenly all internet traffic is disabled because your ISP won't forward your requests, and many devices attempting to connect to any site anywhere are instead infected by the super-virus. Everyone is now too afraid to go online or have already had their devices infected, and depending on how nasty the virus is even after new ISPs are built people will be afraid to go online until they find ways to fully protect against the virus and stop it from spreading to the new ISPs via infected systems that connect to it. [Answer] It is not possible, because the Internet is not a thing - it is a relationship. For example, imagine 20 people in a book club. The book club is not a thing that can be pointed at, it is the relationship between the 20 people all talking to each other about the books they have read. How would you "destroy the book club"? Well, you could stop all the people from talking, that would seem to have destroyed the club. However, as soon as two of them meet again and start talking, the book club is established again. The only way to really destroy the book club is to kill all the people. The same goes for the Internet. The only way to really destroy it is to destroy every one of the billions of devices talking to each other. This is not possible, short of annihilating the entire surface of the planet. Well, not without magic (or sufficiently advanced technology :-), anyway. A single computer virus wouldn't work, as the billions of devices are running hundreds of different operating systems, many of which can't actually be modified by software. I guess you could do it by writing multiple viruses, one for every operating system version used across the planet, but that isn't practical (or even possible?). In any case, all of the important machines have multiple backups, which a computer virus can't destroy. [Answer] This gives a clue on one way to do it: [Someone Just Tried to Take Down Internet's Backbone with 5 Million Queries/Sec](http://thehackernews.com/2015/12/dns-root-servers-ddos-attack.html) Botnet tried DDOSing the main root DNS servers, and knocked out 3 of 13... Which means there are [13 targets](http://www.iana.org/domains/root/servers) that would need to be taken out to cripple most of the internet. They were using a DDOS attack, but a well organized physical attack could work better, and be longer lasting. It probably wouldn't take it down forever, or even very long, but as a first strike it could be very effective. [Answer] If you want to take down the internet you want to take down [BGP](https://en.wikipedia.org/wiki/Border_Gateway_Protocol). This is the protocol that internet providers use to exchange information about which networks are connected to which internet provider. Without BGP the internet providers wont know where on the internet computers are. The internet will essentially fall apart. Each provider will still be able to communicate internally, but they won't be able to communicate with each other. And many users likely will perceive the internet as being completely down, since without knowing so they are completely depending on some service outside of their chosen internet provider. Since BGP itself runs over the internet there is a possibility for cyclic dependencies. If you can identify any such cyclic dependencies and take down every BGP session in the cycle simultaneously, then it will be harder for the provider to get the network working again and consequently it will take less resources for you to keep the network down for a prolonged time. Several years ago there was a concern that it is easier for an attacker to take down a TCP connection than it ought to be. Taking down individual end-user connections this way is not particular interesting for an attacker, but if the attacker could target BGP sessions instead, each TCP connection the attacker kills has a much larger impact. An MD5 digest option has been introduced in TCP to protect against this attack. Because of that protection that particular attack scenario probably wouldn't work today, but there are other possibilities. You may be able to overflow the routing tables with too many routes. Last year one internet provider did that by accident and knocked several other providers off the internet for some time. If you combine such an attack with route hijacking, you may even be able to get legitimate networks to help you by sending out more announcements of the networks you are trying to hijack. But the most effective attack would be the one that nobody else knows about yet. If you can find a 0-day vulnerability in the most popular BGP implementation among internet providers and attack that, then you could probably succeed in taking down the internet until they figure out how you did it. [Answer] @dsollen is really right, taking down the internet is not very feasible, short of total annihilation of most of the planet surface and/or the entire planet. One possibility remains however, which is a bit less destructive than complete surface annihilation: ## Large scale Carrington event A solar storm on the level of the [Carrington Event](http://en.wikipedia.org/wiki/Carrington_event) could theoretically take out almost the entire electronic infrastructure of the planet in one swoop. True, there will be small remaining networks consisting of servers and grids which were specially shielded against EMP and the likes, but with most of the world-wide power supply gone there goes also 99.99% of the grid, publicly accessible servers and end-user appliances. Note that a Carrington Event is a fairly apocalyptic scenario, which would throw the world as we know it into utter chaos. The solar storm would fry the entire electric grid, including large scale capacitors/transformers that would take years and years to rebuild. No electricity would mean that gas stations stop working, which means the supply lines break down almost immediately. [Answer] General advice: learn how the internet works. It's fragile in many ways. There's actual scientific literature on how the internet is vulnerable to attacks. One observation is that there are [relatively few tier-1 network providers](https://en.wikipedia.org/wiki/Tier_1_network#List_of_tier_1_networks), each being integral to the internet as a whole. Take down a significant number of these, and the *global* internet is dead. One way to do that is to just pay off all of the staff in the relevant departments, e.g. by offering them better-paid jobs. They walk out en masse, failure is only a matter of time. Direct sabotage is also an option, of course. A few bad routing tables at this level have serious impact. [Answer] Back in 2008, a misconfiguration by Pakistan Telecom caused [all of YouTube's IP traffic to be routed to Pakistan](http://arstechnica.com/uncategorized/2008/02/insecure-routing-redirects-youtube-to-pakistan/). Hopefully they've fixed that problem by now, but there might be other router-level security holes you can exploit to misroute traffic, potentially causing confusion and slowdowns across a large area. [Answer] Subvert, extort, blackmail, recruit, or otherwise gain control of [these guys or their keys](http://www.theguardian.com/technology/2014/feb/28/seven-people-keys-worldwide-internet-security-web). [Answer] This is going to depend on what you call "The Internet". If you use the definition used by my grandmother, just change the "A" DNS record for aol.com. If you use the definition by my niece, she'll understand the Internet is down if you just change the "A" DNS record for facebook.com If my ISP were completely unavailable, I could still use the IPv6 protocol, or the IPv4 protocol, for my own equipment (assuming my own computers worked). I have a networking savvy friend who I could also connect with fairly quickly. It may be worthwhile to understand that an Apple ][ can be used to connect to the Internet. So, to be specific, you probably want to make the "backbone" non-functional. There is no reasonable way to do this. People have looked into turning off the IPv4 Internet, and it was deemed to be unfeasible (without causing unacceptable collateral damage). > "I would rather the infrastructure to remain, as opposed to destroying all of the associated communications networks." However, the associated communication networks have started to rely on the Internet. There is no way to turn off the Internet without massive collateral damage. [eWeek diversity](http://www.eweek.com/enterprise-apps/verisign-embraces-open-source-freebsd-for-diversity) quotes Verisign: "It's important for us to maintain the reliability of all the services, so we don't rely uniquely on any particular implementation in the operating system space," Kaliski said. "Having both FreeBSD and Linux makes it possible to have that diversity." So much of our society has started to use "Internet" connectivity, due to cost advantages, that any attempt to dismantle the Internet would result in people re-creating the cost benefits, by re-creating the Internet. If every Microsoft Windows machine and Unix server were somehow magically wiped clean, people would instantly create new networks, using IP (because enough people DO have the IP communications details memorized) using whatever equipment remains, even if those are Apple ][s, Commodore 64s, or Pepsi Cola cans tied together with strings. We've learned enough about the benefits that many people would be getting functional "Internet" communications up and going even before most people heard that the old one disappeared. If we had to use "Walkie Talkies" to transmit via Morse Code, we would start with that, and keep improving from there. Once people are creating Internet communications, the only remaining step is for them to use the communication infrastructure to connect their different pieces of self-created Internet. If you're looking for a fictional scenario, you'd probably want to envision a different Internet, which uses addresses that are generated by some key piece of technology that breaks. Or, you might want to fictionalize an attack of the people (kill the scientists) rather than the physical technology. "The Internet", as a widespread global phenomenon which is highly popular, could be substantially shrunk if a sufficiently powerful and inhumane, hostile government enforced a new prohibition of wired or wireless communications. They might make many people so fearful that they don't consider Internet usage to be a worthwhile risk. However, there would certainly still be an "Internet" underground, just like people today have the "Dark Web" using Onion/Tor/etc. Perhaps a more realistic fictional scenario would be to assume that firewalls became defeatable (they essentially shut down, denying all traffic). It might be a story that sufficiently convinces the masses. However, the truth is that trained technicians would figure out a way to handle this, just as people do use the current Internet (e.g. E-Mail) despite constant spam, existing DDOS attacks, etc. In this universe, people embraced standardization, and communication with other implementations, and so there is no simple point of failure. The Internet was built with the concept of flaky equipment in mind, which is why it "heals" so well if damage occurs. Since it is so resilient, rather than vulnerable, nothing short of EMP-style destruction would stand a chance, and the ability to recover would only be limited by troubles being able to run automated machinery again. If you're looking for a super-simple attack, I'm going to stick my neck out by saying: There isn't one. That's by design. [Answer] @dsollen has really given the correct answer to this. But I want to expand on the computer virus part. Any normal computer virus will be discovered, detected and countered within days. As @MichaelHampton mentioned, the [Morris Worm](https://en.wikipedia.org/wiki/Morris_worm) took down much of the Internet in 1988. The first day was chaos, but then the important routers was reconfigured to stop the worm from spreading on the Internet backbone. After that it was a local problem and cleaned up in a matter of days. Since 1988 we have become far more paranoid about how we do the Internet. Pulling something similar today would be *nearly* impossible. What is needed is an **Artificial Intelligence virus**. I.e. [Skynet](https://en.wikipedia.org/wiki/Skynet_(Terminator)). This AI would be a specialist in discovering new security holes in all operating systems. When it has access to a computer with a given operating system, it reads and reverse-engineers that OS, finding new holes. As one hole is closed, it switches to another. To get it started, our clever Hackers manually gives it access to machines with the major OSes, for computers, network routers and phones. First it needs a quiet phase where it just spreads. Then, it strikes... If you want to, you could leave computers running perfectly, except that their network cards somehow doesn't seem to work. During the pre-strike phase, it can give fake work orders to build a second independent internet for its own use. The AIs' various parts can use it to spread information about new security holes. This net can be kept running after the human Internet is down. If the Hackers ask nicely, they might be allowed to use it too. Even so, it would probably not be a total victory. There are many OSes out there. If the AI doesn't have any infected ObscureOS computer to experiment on, it would have difficulties finding that first security hole to get started. This will make ObscureOS computers immensely popular until the Hackers get their hands on one and break it open. Que EvenMoreObscureOS. If the superpowers manage to track down the Hackers, they will not be gentle. [Answer] **NTP Amplification / Distributed Denial of Service (DDoS) attack.** NTP = Network Time Protocol. It's used to sync internet-connected machines and their clocks. This sort of attack is when a packet is sent to a server but the response is disproportionate to the original packet's size. It utilises the UDP protocol which is basically sending larger sized packages as opposed to TCP which is faster and smaller. NTP amplification is reflective. The response is sent to a spoofed IP address. The attacker sends a packet, and the server responds to the spoofed IP with a huge, disproportionate response. It targets NTP servers which support the command *monlist*, which returns the last 600 clients that connected to that server. With a fully populated monlist response, it responds with heavier amounts of response data. Another command is *any*, which returns DNS zone information. With a collection of NTP servers, you can easily redirect entire megabytes of traffic and data to a built network of machines and servers. If you have enough resources and data, it's a wonderful way to attack the entirety of the internet, or at least a huge portion of it. The power of the amplified attack is that the return is much larger than the request. Depending on your connection, you can flood everything with Mb or even Gb level traffic. If you sustain the attack and/or combine it with a physical attack (perhaps an ISP/DNS/intercontinental cables terrorist group) for long enough, you can likely disrupt the financial stability and infrastructural stability of the internet enough to render it, in a fashion, eradicated. [Answer] In the absence of a "hard science" tag, there are a number of science fiction tropes which could do the job... * A metal eating virus or nanite swarm which loves to munch on wires and hard-drive platters. ...or a processed-silicon-hungry variant of either which eats all our chips. * Earth gets invaded by Aliens who strip the planet of metals before moving on, trapping humanity in a permanent pre-technological age. * A shift in the local laws of physics, either increasing the electrical resistance of the metals which we make wires from, or increasing the magnetic decay rate of the metals we make hard-drives out of. * Kill off all the humans who know how to use computers. or my favorite... * A computer virus which eats all of the "\" and "/" keyboard input, leaving us with no way to change our computer's current directory and/or website URL. [Answer] ## Destroy most of switches It is plausible to accumulate a remote exploit for multiple popular families of commercial network switches - i.e., not your home wifi/router, but the ones that your ISP would be using. Such a remote exploit can be used to develop a worm that can rapidly (timescale of hours) scan and infect a large portion of global networking hardware. It is also plausible to have a payload that will physically damage the hardware, for example, by overwriting firmware chips to 'brick' the unit. It's not trivial, but such attacks exist. Having a worm that rapidly spreads and at a set time destroys a large proportion of networking hardware can take down most of internet for a prolonged time - sure, some fragments will remain functioning, but you would expect many data centers to lose connectivity and be unable to quickly restore it simply because the replacement hardware would be very scarce until more can be manufactured. [Answer] If your world had a large conspiracy among relevant hardware manufacturers, a [Hardware Trojan](https://en.wikipedia.org/wiki/Hardware_Trojan) could act as a kill switch inside of chips vital to the continued functionality of the internet. We have [suspicion](http://spectrum.ieee.org/semiconductors/design/the-hunt-for-the-kill-switch/0) of this being done already in military operations. In [Operation Orchard](https://en.wikipedia.org/wiki/Operation_Orchard) it was probably radio frequencies. In network hardware it could be looking for a specific packet. Hardware Trojans can be really hard to detect; there isn't really good software to do it automatically because of the complexity of many hardware designs, so you need expert eyes on every design you want vetted. And even then there's no guarantee that the chip design you send off to manufacturing is the one you get back; you have to physically scrape layers off of the chip and painstakingly map things on the chip to things in your design to figure that out. The problem here is that the process destroys the chip, and only examines a single chip. On the other hand, Hardware Trojans are also hard to design. Your chip has to be about the same size, take in and put out about the same power, etc. Due to cost concerns I don't think a lot of effort goes into looking for hardware Trojans relative to their potential for damage, so to me this seems believable. [Answer] I really like [@kasperd's idea of using BGP](https://worldbuilding.stackexchange.com/a/31483/16108) do destroy the routing information between the Autonomous Systems (networks) which the Internet is comprised of. It is relatively plausible, but the effects are unlikely to last long - system administrators around the world would scramble to define routes between trusted hosts manually. The Internet would soon rise from the ashes, but maybe a bit slower until a BGP-like protocol with cryptographic signatures takes over. Alternate proposal If your work is not set in today, but in a plausible future: # Take down national firewalls Prerequisite: All over the world, national parts of the Internet are separated from each other. Think "Great Firewall of China". The stated reason for this are some high-profile things, like terrorist organizations spreading propaganda, or simply foreign companies refusing to pay local taxes. If you like, you can also add others who campaign for such things for their own reasons, e.g. people wanting to twart copyright infringement. Once the firewalls are in place, they can be attacked and taken down, thereby taking others with them. [Answer] Most of the core routers and DNS infrastructure is maintained by a rather small group of people who know each other well, and who have very efficient communication channels that they normally use to keep things floating, e.g. if there is a large-scale DDoS attack going on, this is where countermeasures such as disconnecting links and dropping certain traffic are coordinated. The Internet works this well because this group is self-selecting and interested in keeping the network running. Now if there were an event that would convince this group of people that it was preferable to shut down the international links, they could do so, likewise for the DNS roots. [Answer] Finding a bug in DNS or common routing protocols, etc. could simultaneously take down all the redundant networking infrastructure. It's not likely in the real world but it is fictionally plausible. [Answer] Information stored on the internet still exists if you destroy the internet because most a lot of important information has backups. Even an EMP wouldn't make the knowledge of Wikipedia to be lost. If you however just want the internet to breakdown make a party attack intercontinental cables. If those get destroyed the global internet as we know it breaks down. [Answer] There are a lot of good answers, and mine is more of a tie-in than a completely new concept. ## Destroy the Hubs: The *Global* Internet, as another poster mentioned, is tied together by a countable number of fiber optic and copper cables. [As shown here.](http://www.zerohedge.com/sites/default/files/images/user3303/imageroot/2014/06-overflow/20140619_fiber.jpg "As shown here") The other interesting thing is that they go to a countable number of cities, and from there are distributed to hundreds of adjacent cities and counties. They all follow the old phone lines, with follow the telegraph lines, which follow the railroads. Hundreds of years of consolidating our infrastructure into a few key places. Two dozen nukes would take down the entire US, given proper placement. And its not just DC; Kansas City is a good target. And the pattern is repeated globally, so you can keep most of the hardware or current day, but still take down the Internet (and a bunch of other stuff too) with a few focused attacks. ## Rebuilding and Rerouting: As others have mentioned, this wont forever destroy the Internet. Data will get rerouted and so will everything else. But I picked nukes for a reason: By denying the area itself, the entire city and surrounding area, you will severely limit the effectiveness of the rebuilding effort. Those places were Hubs for a reason to being with, versus whatever city is 50 miles upwind, and those reasons don't go away. Data, goods, and whatever else will start flowing between places again, but "The Internet" wont look anything like it does today. No more Facebook or Youtube, the prices for 'decent' internet will skyrocket, and only major businesses and gov't will be able to use it routinely - everyone else will not only be stuck without Internet, but phone, cable, etc.. will be gone from a regular persons life too. The upheaval will last quite a long time. [Answer] It is impossible, within your conditions. Note: **your given requirement to shut down the internet *is without leaving any information available*.** That is even more strict as your title asks. The internet is no media where something can be stored in. It is just a..... well.... *network* of connection between hosts. So to make any data unavailable, you had to destroy binary media. So any mobile, any pc any fridge that works wiht a controller.... and anything that would be able to physically store data in anyway that could be retrieved by such a medium connected to the network. You know, the internet isn't a thing. even if all computers were eliminated, nothing would stop (expect the dumpness of the idea itself) humans to communicate verbaly over tcp/ip as language. What theoretically could be fitting into the definition of an network based on that protocoll aswell. and so, since the protocoll itself is jsut an idea, you can't destroy it without eliminating each medium hosting it. In other words your definition of taking down the internet is "extingushing humanity" since you require to make no information of it ever be available again. so as others have allready adviced, but in other context. The only way to achieve this is: Nuke the planet containing the idea and its mediums storing it out of existance. Everythign else will at least leave the possibility of medias (of what ever origin) be starting again to communicate over tcp/ip ;) [Answer] Stop filtering spam and viruses. The pest will grow all by itself and take up any possible room^Wbandwidth, like a gas. [Answer] I believe the only sure-fire way of accomplishing this **cleanly** would be through an uncrackable, artificial-intelligence-based virus. The virus would have to be: * programmed with unbreakable coding * completely dynamic, made possible by AI programming techniques * spreadable by many technological avenues * able to exploit human psychological/sociological tendencies [Answer] A [Coronal mass ejection](https://en.wikipedia.org/wiki/Coronal_mass_ejection) that is big enough, [could take out the entire power grid](http://aviationweek.com/awin/major-solar-event-could-devastate-power-grid). > > In a “perfect storm” scenario, when a high-power coronal mass ejection (CME) of charged particles slams into Earth at a time when the delicate balance operators try to maintain in electric power grids is precarious, the resulting damage could take a decade to repair at a cost very roughly estimated by the National Academies of Science as high as $1 trillion. > > > If this happened, it would take out the power grid, for about a decade, and without power, all out the computers, servers, and everything would run out of power, and die. RIP internet, for atleast a decade. Plus, it would cost tons of money to fix (1 trillion). ]
[Question] [ Santa is Satan, after all the clue is right there in the name. But why? What reason would the font of all evil and the generally unpleasant one have to pretend to be a jolly fat man and give away presents to make people happy for one day each year? Answers will be judged based on plausibility. Would a very powerful evil being of corruption and darkness actually think that's a good plan? [Answer] If he did not provide happiness at the darkest time of the year, nobody would want to bother living. A lot of people look forward all year to Christmas, even though it is generally the coldest and darkest time of the year (especially when it doesn't snow). If people didn't have Christmas, they wouldn't have very much to look forward to. This would mean that a lot of people just coast through life. They wouldn't feel very happy, but they wouldn't feel very miserable either. Satan **hates** this. He wants to see people at their **worst**. This is why, for a single day every year, he provides us with hope. We get one day every year to look forward to in order to receive gifts, have time off work, and generally relax and have fun. Then the other 364 it's back to the regular grind. If humans did not have anything to look forward to, nothing to hold on for, then we could never feel the depression of January when we realize it's still cold and dark, but now we have to wait another year for presents and time off. If we didn't have Christmas to look forward to, we could never feel the sinking feeling of disappointment when we receive terrible gifts that we have looked forward to receiving for months. We would never have the abject terror of thinking loved ones will realize we hate their gift, so we rush to plaster fake smiles onto our faces. He gives hope, for the *sole purpose* of then getting to rip it away. [Answer] ## Encouragement of greed, selfishness, and stress. The American Psychological Association even released [a memo on holiday stress](http://www.apa.org/news/press/releases/2006/12/holiday-stress.pdf); the top three negative emotions experienced were **fatigue, stress, and irritability**. **38%** of people polled responded that the level of stress in their lives **increased** around the holidays; **lack of money** was the second leading holiday stressor. People have even been [**physically injured or killed**](https://en.wikipedia.org/wiki/Black_Friday_(shopping)#Violence_and_chaos) as a result of attempting to best fulfill Santa's dastardly holiday. Additionally, **it robs the focus of the holiday from spirituality** and shifts it towards the receiving of material goods. It can also **increase feelings of isolation and loneliness** for those who are forced to work on the holiday to perform services for consumers or to earn wages to pay for gifts, when they could otherwise be spending quality time with loved ones. Therefore, it is inevitable that we must conclude... **the *real* war on Christmas is being led by Santa**. [Answer] **Stealing attention from Jesus** While Jesus represents the religious meaning of Christmas, Satan Clause represents the secular aspects. By shifting peoples attention away from seeing Jesus as the symbol of Christmas and to worship a secular symbol instead, he turns people away from faith. **Making people more materialistic** Satan Clause doesn't reward people for good behavior with absolution for their sins and an eternity in heaven. He rewards people with material goods. But Jesus told us, craving materialistic wealth is wrong ([Matthew 6:19-21](https://www.biblegateway.com/passage/?search=Matthew%206%3A19-21&version=NIV)). People should be nice for niceness itself, not just for their own benefit. **When Satan Claus gifts to the poor, others don't need to** Charity is one of the seven virtues of Christianity. According to the bible, giving to those in need is important to receive salvation. But when Satan Clause gives presents to the poor, rich people will no longer feel the necessity to do the same. Rich people are already a main source of souls for Satan ([Marc 10:23-25](https://www.biblegateway.com/passage/?search=Mark+10%3A23-25&version=ESV)). But by discouraging rich people further to be charitable, it becomes even more likely that their souls will become Satan's after judgment day. [Answer] The [seven deadly sins](https://en.wikipedia.org/wiki/Seven_deadly_sins) are greed, envy, gluttony, sloth, pride, wrath, and lust. The entire point of Christmas is to encourage greed, envy, and gluttony. The tradition of giving gifts encourages the first two, and feasting encourages the third. Santa just oversees it all, and gives the gifts that will best fan the flames of these sins. **Greed**: People asking for, hoping for, wishing for big expensive gifts. Retailers going to ever more excessive lengths to boost sales. Commercials encouraging even little children to beg for impossible toys. Greed is everywhere this holiday season. **Envy**: Some people can afford more than others. The nice things on TV or on the shelves that only a few can afford encourage huge amounts of envy. It's a fact of life, but in the Christmas season, it gets rubbed in the face of the have-nots. **Gluttony**: Who hasn't gone to a Christmas party and come home drunk, stuffed, or both? It happens to most of us several times over the Christmas season. To a lesser degree, Christmas fuels sloth, pride, and lust. **Sloth**: Christmas is a day when people do not go to work, and many take the day to do nothing. Sure, there are others hosting their family's Christmases, but I'm talking about the people who open gifts in the morning, then do nothing else for the rest of the day. Not to mention all those gluttons sleeping off their excess. **Pride**: So much of Christmas is about excess: showing off with parties and lights, buying expensive gifts to prove you can. All this pride is not good for the soul. **Lust**: Have you watched the commercials lately? They use sex to sell everything these days. The season doesn't encourage wrath in particular, but Black Friday has filled some of the gap. You haven't seen wrath until you've seen a dad who missed out on the last must-have toy on the shelf to some over-aggressive grandmother. [Answer] Also, by constantly monitoring children to see who is 'naughty' or 'nice', and letting them know it, Santa is psychologically grooming the world to become a surveillance state. Why not let businesses and governments monitor us at all times? The wonderful Santa does it already. In addition, Santa enters people's houses without their permission or even without their noticing, thus normalizing home invasions as a tolerable or even a desirable activity. Clearly Santa is attempting to usher in (sweetened by the giving of gifts) a future dystopian corporate-government surveillance state. Nothing would give more joy to Satan, er, Santa. [Answer] **Because (almost) *everyone* loses faith in Santa** Well, *everyone* knows Santa isn't *really* real, right? I mean, sure, when you're a kid you believe in him, but then, one day, you find out he's not really there, that it was just your parents all along. You, know, if Santa's not real, there's probably no such thing as magic, after all. There's just people and rocks and space, and nothing special or magical or spiritual out there. And, you know, if there's nothing spiritual about the world, then we surely don't have souls, and God probably doesn't even exist. And, well, "if God does not exist, everything is permitted". [Answer] "Would you like some candy, little girl?" Satan wants to encourage dependency and entitlement from a child's earliest moments of sentience. He can build on this through the elementary-school years, encouraging a demand for *things things things*, and *now, dammit*. He wants those kids to grow up thinking the world owes them, but he has to start with one fat guy in a red suit owing them. Just as candy from strangers is the first step to drugs and gangs, toys from strangers is the first step to teen years filled with petty crime to support one's online-gaming habits (the Warcraft mods on eBay are so attractive, and really not that expensive all things considered!). How does this serve his purposes, you might ask? When he gets lucky he'll create the next wave of teenage thugs and criminals, but the *real* payoff is with the ones who stick with school, go to college, and end up on *Wall Street*. Satan is hoping to draw everybody with a tendency toward greed, materialism, and the desire to play with other people's life savings to one place, where he can hang out with people who understand their priorities in life. Sure, he figures he'll get them later in another place, but you can't beat the night life in New York City and Satan gets lonely down in the firepits. [Answer] 1) Santa doesn't pretend to be good, Satan pretends to be bad. Due to how the universe works, God needed an "evil" counterforce to his "goodness", so he selected his most trusted angel, Lucifer Santa di Angelo, to become Satan. As part of the deal, Santa may show goodness one day each year. 2) Santa is so good, and so powerful an entity that for 364 days each year he is sealed away by a pantheon of other gods who do not wish to cede control over humanity. They tried to frame him for all the bad things "he" does, but unfortunately registered the wrong trademark when casting the sealing spell. (inspired by ESV:SI) 3) Satan is a bad boy, but even a bad boy can treat his woman to a nice dinner once in a while. He is the manipulative, abusive boyfriend of humanity, and we forgive him every year when he showers us with presents. 4) Satan uses a once-per-year chance to install surveillance devices in gifts. This started in 1933, when the then fledgling NSA approached him in his holiday home at the north pole (similar temperatures and all that). In return he would receive souls, which would be later covered up using CIA resources, including the "MANHATTAN PROJECT", "MKULTRA" and the "VIETNAM WAR". In recent years this operation has unfortunately not borne any fruits due to religious nature of the NSAs target audience. [Answer] Santa is not Satan, but an equivalent opposite of Jesus (with some differences regarding origin). Santa is to Jesus what Satan is to God. However, this does not make him less demonic, evil, or corrupted. Let's explain this: # The beginning Santa and Jesus had a fight since the 300 A.D. when Nicola (Say, Nicolas) from Bari had a strong desire for increasing power. Indeed, he -helped by the Devil- gave even more power to the uprising Church over whole Rome to manipulate what Jesus told us about sins and virtues. [![enter image description here](https://i.stack.imgur.com/QH04y.jpg)](https://i.stack.imgur.com/QH04y.jpg) The first concept to be twisted was Charity, both in the spiritual and / or material aspects. Several texts were told by him to be destroyed, including texts from Origenes telling about reincarnation, which would be lately (553 D.C.) replaced by latin analogues of greek's hell. People had no motivation to praise God but the ultimate reward: a place of eternal joy, instead of a place of eternal fire. Christianity, which was designed to fit in a context where other gods commanded the lives of the upper social classes, quickly turned on being a selfish, aggressive and stalking religion against others, since he reinforced the concepts on [Deuteronomy 13:9](http://biblehub.com/deuteronomy/13-9.htm). # The name People who testified enough -and lived to record it- called Nicolas as *Satanica Clavis*, since they feel their community was invaded by the sin, and since Peter has the key to the Heaven -under the new doctrines- Nicolas had the key to the hell (by telling people to behave like that). Since that people belonged to lower classes, they were a minority and had no access to records (writing books was quite expensive), so the name was... mangled over the time, and turned into Satan Clauis and finally Satan Claus. Church itself was invaded and later declared Nicolas as saint (In spanish he is called *San Nicolas de Bari* since he was born in Bari, or *San Nicolas de Mira* since he died in Myra), the name was mangled once again to be Saint Clauis, and finally Santa Claus (today, some english texts refer him as *Satan's Claws* since it's a joke on his name when he was the main consciously servant of Satan in the Earth). # The bound with (the actual) Satan The red suit came as a requirement from the Devil itself, so since he was well-accepted and established figure in the christian *pantheon*, he did not need to use his white-golden clothes (or green clothes) anymore, and switched to the well-known demonic red we know. His transport ([originally based on this God-proof chariots](http://biblehub.com/judges/1-19.htm)), however, was pulled by infernal goats (those usually used as focus icon on satanic rituals), but he switched to deers because: * The number of prongs matters. * They are more suitable to keep a straight line. * They made less noise!. * Their nose was better to be turned into infernal lamps to light the midnight sky with that hellish-red tones. So people would feel more familiar to the hell colors than heaven colores they were told to worship. By doing this, Santa Claus would gain immortality, while being forced (or say, under agreement) to do actual Satan's Commandments. # His mission Satan's commandments were as follows: * Destroy the remaining theologal virtues: faith and hope, and ensure people would not recover Charity anyhow. + Hope was already told by other users, as how was it destroyed. + Faith requires another twist: toys gave by *Santa* had no distinctive mark of being somehow divine, so people lost the faith on (the *need* of) God but just the Humanity itself. + Charity was *compressed* in just one day, and by just one person. Santa's gifts were a better and more visible gift than Jesus' eucharistics... suppers. * Destroy any terrenal virtue by encouraging the 7 capital sins. They were all described by other users, except for **wrath**: these dates stress even the most patient kung fu practitioner (when they have Christmas, as of today) when it is regarding finding gifts in malls on days 23 or 24, right on the edge to the... timeout. * Forget also Jesus, at all. In fact, Jesus was turned into a representation of in-Earth suffering just to wait for a reward of a supposed heaven so... why ever worshipping him? [![enter image description here](https://i.stack.imgur.com/aBNke.gif)](https://i.stack.imgur.com/aBNke.gif) Finally, houses and everywhere would be decorated with hellish-red for their furnitures. # As of today It is told that Santa is the actual owner of Coca Cola, which continuously releases commercials telling about *opening happiness*, which showing the idea that happiness is caged in a bottle of brownish liquid, instead of the happiness offered by Jesus. [Answer] From the christian point of view, **giving** is more important and noble that **receiving**, and Christmas is that time of the year where this is more evident. If "Santan" fulfills everyone's wishes and gives everybody gifts, then people would stop to care about being generous to others (because there's already someone who takes care of that) and instead would just expect to receive things. This removes a crucial aspect of Christmas. Also, as mentioned in another answer, this draws attention away from God and Jesus; but apart from that, it (ironically) draws attention away from the devil itself. It is stated that one of his greatest achievements is for people to stop believing in Satan so he can make people do evil stuff easier. [Answer] Did you ever notice that the children of rich families get more presents than those of the poor? That's great for instilling even more envy against them than there is anyway. Also, while it is claimed that good children get presents, but naughty children only get coal, the reality clearly looks different: Lots of naughty children get presents. Thus they are encouraged in their naughtiness, which clearly is a goal of Satan. Then there's the whole materialistic aspect. You know, the bible says you cannot serve both God and Mammon. But Christmas presents are ultimately a celebration of Mammon (in the form of the stuff you can buy with money). So Satan turns a celebration of Jesus into a celebration of Mammon. And finally, with carefully selected presents, he can also foster discord between the children, especially if there are several children in one family, and one gets more than the other (or gets something perceived as more by him/her). Therefore bringing presents can also be a great tool to turn a celebration of love into a source of conflict. Note that conflict between the children will inevitably cause stress also for the parents, and is likely to produce a negative feedback loop. You see, bringing presents is the best way for Satan to bring evil into the families, and to pervert and thus devalue Christmas. [Answer] **The presents are positive reinforcement to keep being loyal consumers: succumbing to greed, coveting their neighbor's stuff, and living in excess.** Being a true capitalist, Santa resides outside the countries he does most of his work in. He works the local population every day of the year with no semblance of a living wage or even merely gratitude. He's paid through the small traces of gold in the cookies (placed by the corporations he produces toys for) left out for him. It's all a grand-scale advertising campaign paid for by slave labor. *Rise up comrades! Down with the toymaker!* [Answer] **Greed is good** This world has totally bought into the idea that Independence is everything; that the only purpose of existence - the only moral good - is to fulfil your own desires. To do anything else reduces your level of self- actualization; it betrays your destiny and thwarts the evolutionary drive towards improving the human race. The God of this world embodies those values precisely. In this world Santa's values are the exact opposite. He encourages people to give without expecting anything back, increasing someone else's happiness rather than your own. He represents rebellion against the values of the world - the anti- God or 'Satan'. No wonder he hides in the most remote part of the planet for 364 days a year. [Answer] Satan is a supremely powerful being. However, one must suspect that there are greater powers. In the Abrahamic religions we see themes of darkness conceding to light, righteousness triumphing over treachery. If Satan represents an all-mighty, unstoppable force of darkness he would have control over the universe. By his sheer power alone, he would be able to overcome God. From this one might wonder if even Satan himself must obey a set of moral guidelines so as not to displease the higher powers. Why does Satan get to avoid Judgement Day? Satan consistently causes pain and suffering. Furthermore, he loves it, he relishes the opportunity. He must have a way to balance his morality. How does he do so? The answer is in his name: Santa. By performing such a far-reaching act of kindness on one night he makes up for a full year of sinning. While some gifts may be materialistic, Satan is responsible for the magic of christmas. Families reunite, people fall in love. Satan loathes performing such a virtuous act, but he must do so or else fall to a greater authority. [Answer] Satan is not in fact evil, but a propetant of human enlightenment and freedom against a tyrannical god. He just wound up on the wrong side of "the winners write the history books". [Answer] It's in the good book: > > And no wonder, for Satan himself masquerades as an angel of light. > > [2 Corinthians 11:14](http://biblehub.com/2_corinthians/11-14.htm) > > > Just for the sake of appearing good, Satan will have to do *some* good. [Answer] ## Mass confusion and international conflict If Santa really did manage to deliver millions of presents in a single night all of a sudden, how are humans going to react? The most likely reactions: 1. Jesus exists, and has given Santa powers for good. 2. There exist alien species on our very planet with highly advanced technology. 3. Somebody living on the planet possesses advanced technology, such as teleportation, or a quantum photocopy machine, etc. 4. Magic that defies current science does exist, and is being used either by some humans or some alien species. There will be chaos, as world leaders and common people struggle to reach a consensus with their own rationality, let alone the rest of the country or the world. **Massive investment in investigating the presents will follow**, and the source of every single present will be traced down. Businesses that supplied the presents will be questioned, transporters will be questioned. Different countries will want to conduct their own investigations that will come into conflict with each other. **Scientific methods will be discarded** by millions, maybe billions of people. This is essentially a degradation of civilisation. It takes only a bunch of lunatics to cause a riot, or even fire a nuclear weapon. Governments may fall, religious conflict will ensue. "Santa" will now be viewed as a curse, not a saint. **People will no longer feel safe in their homes.** If a man can enter millions of homes in a single day, what else can he do? One could also argue that **if such a powerful man was indeed benevolent, he could use his powers for much greater things, such as combating poverty and sickness**, as opposed to presents to rich kids, and a wave of confusion. This proves that "Santa" is manipulative and a potential threat to humanity. **Satan can then use his other powers** to possess people and take advantage of the confusion to destroy the world. [Answer] # Hope and Fall Satan is the devil, he tries to make our lives painful and even worse when we die. If our world is only pain and evilness people will "adapt" to survive and support this and they won't suffer anymore (or at least they will suffer less) and Satan doesn't want that. If he every year makes gifts to all the people in the world he increases the hopes of people and also brings them happiness to survive in this world. I think this is "good" to him because he can make their lives even more painful. Think about this: you are a poor person who lives in an abandoned building. One day this building is destroyed and you lose your "house". This person won't suffer much because he is already suffering, but if this person was rich and one day he lost everything he would suffer a lot. The "fall" would be bigger and Satan wants that. He brings hope and happiness to us to suffer more and have a bigger "fall" when we die and go to hell. Also, he can play with the "coal" gifts: you were waiting all year long for your gift and on Christmas you get coal. This would be very disappointing. Also, you can use Christmas to make people sad indirectly. I am not sure but Christmas is the day with the most suicides because people suffer when they see happy families and they are alone. # Sins Satan uses Christmas to increase the sins of people and corrupt their souls. On Christmas people are very: * Greedy: they want the best gift. * Envy: some people can't afford good gifts and others can. These people are envious of rich people. * Gluttony: in a lot of countries there is a tradition of eating a lot of yummy meals and sweets on Christmas, Easter day and new year. * Sloth: some people take the day free. * Pride: people sometimes buy the most expensive gifts and decorations for Christmas in order to show them to their friends. * Lust: from Wikipedia: > > [..] lust could also mean simply desire in general; thus, lust for money, power, and other things are sinful. > > People want material things. > > > * Sadness: like I said in the *Hope and Fall* title some people are very sad on Christmas for not having a family or friends. # Reduce Charity When Santa gives presents to poor people other people (like rich people) don't give presents because they already have one and charity is one of the seven virtues of Christianity. Satan is trying to eliminate one of the seven virtues of people. # Absolution Satan is evil. Sorry, I didn't read The Holy Bible so I don't know if this is true, but God is all mighty, right? So... Why didn't He destroy Satan? My idea is that Satan isn't **so** bad. Every year Satan regrets his sins making gifts to all the people in the world and bringing them hope and happiness. This way God *can't* "purify" or destroy Satan, because he regrets his sins every year. # Christ's attention Christmas is the birthday of Christ but Satan creates the "Santa" character to make Christmas about him and not about Christ. A lot of people don't know that Christmas is the birthday of Christ but they know about Santa. # Materialist people Satan makes material gifts to people instead of a "spiritual gift" like absolution. People try to be good people in order to get a material present on Christmas and not the absolution of their soul. He makes people more materialistic. [Answer] **Downsizing!** Satan wasn't always Santa, but due to celestial budget constraints, quite a few of the classic job titles have been combined. "Satan" and "The Boogey Man", who scare children into behaving, has been combined with "Santa" and "The Easter Bunny", who bribe children to the same effect. This new "Department of Child Control" which also covers the responsibilities of "Tooth Fairy" and "The Closet Monster", is now handled by a single part time celestial employee with no health-care, paid-vacations or retirement benefits. [Answer] **Satan is the good guy** If you read the Bible, God does a lot of killing, raping and slavery not to mention the war and incest, he just happens to have a good PR team that plays dirty and blames everything on Satan despite being innocent and the only proof of the few things Satan is accused of is in God's own book. Satan is just trying to show his love by gifting everyone, one day a year and he changed his name because of the lies God has told to blacken his reputation. [Answer] From looking at the bible and its passages, it was Satan (the angel Lucifer) who was first to sin, not Eve or Adam. And while people say that Satan causes all sin, by posessing those and causing them to commit sin, this is not all true. There have been cases where Jesus has met and cleansed those posessed by demons, but most of all human sins come from within. Looking at the case of Adam and Eve. Eve commited the sin all by herself, she was not possesed at any time, Adam did not even meet the snake and was therefore also not posessed. But Satan did speak through the snake to bring out those hidden desires from within Eve which then lead to her commiting sin. They both sinned by there own will and actions. So how does this relate to the topic of the Satan and Santa, well... > > Let no one say when he is tempted, “I am tempted by God”; for God cannot be tempted by evil, nor does He Himself tempt anyone. But each one is tempted when he is drawn away by his own desires and enticed. Then, when desire has conceived, it gives birth to sin; and sin, when it is full-grown, brings forth death (James 1:13–15). > > > Drawn away by his own desires and enticed. One of the origin stories of Satan was that, as an angel of God, was enticed by his own desire to become higher than God due to his already almost perfect state, this created his sin from pride which was the cause of him being cast from heaven. Another origin possibility was that the angel Lucifer grew jealous of God's attention to humans and went to prove that God's creations could be corrupted by corrupting himself. Both of these bring towards a certain trait of Satan: its not that he directly wants to create sin, its rather he would provide opportunities for others to become corrupted and commit sin. And what better time than christmas. The original idea of christmas is good, give to those who have been good, warn those who have been bad. **But we are human**: we have envy, pride, greed, gluttony, sloth, lust, and wrath. We wish for those things we can't have, we get jealous if someone gets something that we want, we get hateful when someone gives us a bad present, we want to have presents that we can show off to our friends. These are all our emotions which lead us to sin and therefore corrupt ourselves, either removing us from God's influence or proving Lucifer's point that we are corruptable. But this is all just the beginning, while Christmas is just a single day, the time and effort expendature can be considered a labour of months. And while it affects those at all levels of society due to our own desires and expectations. In lower income suburbs, a toy car may be the greatest gift ever to a child. In middle income, that car becomes remote controlled. High income, it is a real car. But here is a fun kicker, what does an over commercialised christmas lead to? Of all things, Greed. The innocent ideals of what Christmas is to promote; love, community, spirit, and all that, gets expolited in other innocent days as well: Valentines day, Easter, love day, birthdays, other holidays which anyone can celebrate. Have all become overcommercialised and strewn away from ideals, all because of the hidden desires of men and women. While the three wise men seem like the good guys in the story, did they predict what their innocent gifts would become? ([{or were there actions their own?? or a far reaching plan of Satan/Santa himself?????} sorry, my own conspiracy theory here. Coundn't resist]) The starter for this all, a jolly man in a red suit. The picture of kindness and innocence, hiding a face of hidden desire. The greatest good can hide the greatest evil, and christmas and Santa are perfect cover for Satan and his influences. And even if the original Santa was pure, his legacy has been influenced to a darker path. [Answer] The opposite side of good is bad, so the bad is the opposite of good. If Satan existed, so Santa must exist to justify each other, else Satan can't exist. If God exists, then Lucifer must exist to justify that God is omnipresence and the creator, of the men and angels; and the most powerful of His creation, Archangel Lucifer the Morning Star must fall to justify God is everlasting and the ruler. If one ow**n**s 100 billions, he is on the shore; yet if for the same figure - 100 billions - he ow**e**s, he is in the deep sea. Thus a play of words A-A-N-S-T is playing on this little string. Of note is, the **n** does look like a holder while the **e** looked like flinging [away the money] :). Maybe this is the genius of the word formulation using also the graphical imagination to construct the word **own** and **owe** in the subconsciousness of the human group psyche, similarly the word Santa/ Satan constructed with the same letters. To emphasize, Santa and Satan must exist so that the opposite of each other can exist, nothing can exist on its own. If we talk about long, that's it compared to short it's called long, so is hot/cold, far/near, love/hate/, evil/good... etc., John is John because there are Tom, Mary, Ann...; Earth because there are Mars, Jupiter...; anything existed because it's different from other *"things that's not this thing"* that this anything got the unique name. --- To play the letters: A-A-N-S-T * consonant: N-S-T * Vowel: A-A SA + TA + (NA) > the 1st two combinations of consonant and vowel is chosen for *Satan*. Thus the only left arrangement of letters following the constrain of SA\_TA\_N is, SA\_N\_TA we have *Santa*! [Answer] **MAGIC**. Satan needs power to do his evil deeds, but after being cast away from heaven he lost his angelic powers. Doing a great good deed once a year allows him to collect enough childish hope and belief to power his dark sciences. [Answer] To power up!! Collecting hopes and childish joys once a year allows him to become more powerful to fuel his dark sciences. However, he also does this to make people to look down on Jesus so he can rule!!! He also fuel sins like sloth, envy, greed, pride, lust, gluttony, and others.[![enter image description here](https://i.stack.imgur.com/kNTcy.png)](https://i.stack.imgur.com/kNTcy.png) [Answer] Almost everyone answering here is a Sith for dealing in absolutes. Notice the small dots in the Yin-Yang symbol? There is a little evil in all that is good, and there is a little good in all that is evil. Lucifer once had a disagreement with his father, which led him to being cast out of heaven and becoming Satan. That does not mean that Lucy is a complete \*\*\*\*\*\*\*, he's more like a "mostly" \*\*\*\*\*\*\* guy. There is good in him, and sometimes he does selfless deeds. The reason he does not get credit properly is twofold: 1. Middle age christians were absolutists who would deny that anything good comes from Satan. But check [the Satanic Temple](https://thesatanictemple.com/)'s ideals and deeds nowadays: > > The Mission Of The Satanic Temple Is To Encourage Benevolence And Empathy, Reject Tyrannical Authority, Advocate Practical Common Sense, Oppose Injustice, And Undertake Noble Pursuits. > > > We have publicly confronted hate groups, fought for the abolition of corporal punishment in public schools, applied for equal representation when religious installations are placed on public property, provided religious exemption and legal protection against laws that unscientifically restrict women's reproductive autonomy, exposed harmful pseudo-scientific practitioners in mental health care, organized clubs alongside other religious after-school clubs in schools besieged by proselytizing organizations, and engaged in other advocacy in accordance with our tenets. > > > 2. The whole trope of mailing him to get gifts started with a huge marketing stunt; Unfortunately it had a dyslexic kid's letter in it, and the wrong name stuck. ]
[Question] [ Rynn is not flashy at all. In fact, you would be forgiven to think she's a bit of an introvert. Sure, the people in the town are strangely reluctant to talk to you about her, but you *are* a newcomer, and after a few drinks tongues eventually loosen up. Children *do* seem to get better when they're sick after eating her oatmeal cookies, you are told, but others quickly add that that might be simply because they *believe* they would. And she did ask for a local brewer's help moving some furniture the very morning his fermentation vat blew up half his house. And there was that time when she happened to be fishing on the lake just as two reckless boys swam too far, got trapped in the weeds and would have probably drowned if not for her. Oh, and the curious incident with the thieves who not only returned her purse but also made a large donation to the orphanage. And ... actually, there's a surprisingly large number of such events and coincidences. Silence descends upon the bar, as people gradually make excuses to go away. You suddenly have a strange, absolute, gut-certainty that if someone were to throw a stone at her head while she was turned away she'd just *happen* to bend down to tighten her shoelaces at that exact moment. Or perhaps she'd trip over a root. You briefly wonder: Is **Rynn a witch?** That thought is quickly replaced by another: Nah, you're just being paranoid. You put your beer down, shake your head and head out. --- **Assume you have someone performing public magic in such a way that it's virtually indistinguishable from luck, or coincidence. Just how much magic can one get away with?** I'm thinking specifically: * Telekinesis (moving small and not so small objects without appearing to exercise any direct influence) * Divination (seeing across future scenarios and actively guiding the future towards a preferred outcome) * Headology (read Terry Pratchett - getting inside people's heads, aka Charms and Illusions) * Evocation (manipulating energy, such as weather, fire, electricity etc) **How should a mage act to make her less likely to be detected? What kind of beliefs in society would help most with remaining undetected?** **Later Note**: See also this **[follow-up question.](https://worldbuilding.stackexchange.com/questions/13285/the-subtle-art-of-fate-stealing)** [Answer] Beautiful Question Prep! Subtle, beneficial magic, wrapped in a shy and unassertive package, unobtrusively making life better for those that she cares for... Rynn falls so far from the witch stereotype that I doubt anyone would ever make the connection. They might think she was charmed, that angels watched over her and kept her from harm. She would be the town's lucky penny, their precious secret. In time, as her life sailed smoothly past the jagged rocks the harass and befuddle everyone else, she would come to be known as wise. Quiet little Rynn, who never speaks up or pushes people around, would have a mighty authority among the townsfolk and few would stand their ground on any issue when she politely took the other side. ...but that is in her future. The younger, apparently innocent and undeniably blessed young lady is the character you have today, and she is a wonderful starting place for all kinds of stories. How far could she push it without scaring her friends? I don't think there is any limit, as long she was generous with the town-folk and never blatantly hurts anyone, she will continue to be seen as, at her worst, harmless. More important than the scale of the magic she casts would be the indirectness with which she casts it. She would always want to make it look like things just happen around her; not that she makes things happen. Hurricanes change paths despite what the weather man predicts, sparing the town and surrounding farms. Rain always falls in their valley no matter how bad a drought the rest of the country is dealing with. None of the town-folks ever locks their keys in their cars... every time they think they've done it, they always find that one of the doors isn't locked. The local locksmith has closed up shop and moved to another town. I am tempted to say that placing your story in an enlightened, scientific age such as today would greatly enhance your character's ability to hide her talents. In this modern world, she could literally conjure dragons right in front of us and we would still be looking for where the mirrors are hidden as the winged ones ate us. Still, since you've introduced this character as cherished by her friends, with shyness and humility to further conceal her power. With those attributes, I think she could live anywhen and nobody would ever mistake her for what she truly is. This is a beautiful character which should be a blast to work into some of your writing. Good luck with her! [Answer] Telekinesis is a tough one. Humans are quite good at calculating trajectories, and unless the magician does something that could be interpreted as the chance interaction of a gust of wind or a lucky/unlucky bounce, altering the trajectory of an object would be noticed. That's something that some CGI movies struggle with. Divination is an easy one, as long as the magician can make things look like a coincidence. Not being in harm's way is a good one, but a careful magician might allow themselves to take small amounts of harm so as to deflect attention from the fact that they're not taking *serious* damage. Headology can be tricky. It can be pretty obvious, or quite subtle. If a magician restricts themselves to the possible, it could only be detected if two witnesses to an event have significantly different recollections of an event. Making someone remember a giant purple elephant in their cupboard would be pretty obvious. As with the example story, a magician who acts to make their magic look as if there were just a whole lot of coincidences and luck happening to them, as well as ensuring that *other* people around them were *also* lucky, such magic could be discounted for quite some time, and given that the "luck" seems to rub off on bystanders, others would be reluctant to act against the magician for fear of losing their luck. Obviously, if such a magician's enemies started suffering *mis*fortunes out of any reasonable resemblance to the normal variances of chance, people might get suspicious. However, if the magician simply altered *other people's* opinion of their enemies in a subtle way, reducing society's levels of popularity and respect, and increasing annoyance with their foe, the magician could see to it that their enemies were run out of town or lynched, and the townsfolk would hardly notice, and would probably think that it was their own idea. After all, "Joe always *was* a pain in the ass, and it's not fair to say he only tormented Rynn when he made *everyone's* life miserable." [Answer] ## Telekinesis You can affect objects already moving in complex patterns. People would be a good example, a person slipping or tumbling for no detectable reason is weird, but would easily and naturally overlooked if something large falls where they would be if they had not slipped. Discontinuities are also good targets. Even if an object has a predictable trajectory you can't mess without it looking unnatural, it can still **bounce** weird when it hits a wall or ground without it being a major issue. Objects can also be messed with when nobody is looking at them. Objects above or behind people present can be made fall down as a distraction and it will look natural enough. An attack looks more unnatural as the "odds" of accidentally hitting someone are longer and people pay more attention to events with concrete consequences, but if you time it to coincide with something that **could** trigger the fall such as slamming a heavy door or something heavy falling, you can get away with it. You can also mess with equipment. Fuses are supposed to trip occasionally, so if you can use the telekinesis to cause a fuse to turn out the lights, you can get away with that easy enough. Likewise if nobody actually has a reason to know which position some switch is, you can flip it even if that has some consequence later. And you can use telekinesis for set up. As an example instead of making somebody slip, you can, while nobody is looking, make something slippery spread itself over the surface people will move over later. You can telekinetically open a lock just before somebody else tries to open the door. You can make a door somebody is trying to force open break easier than it really would have. You can even make an object several people are trying to move move easier because everyone will assume others are doing a more. And even if it is only one person is trying to move it when he is not really paying attention because of some emergency. Which covers most times you'd want to use telekinesis anyway. You can also use telekinesis to avoid something. To make people **not** slip on a slippery surface. To make people not lose their balance on a narrow ledge. To make a door somedy is trying to break not break... ## Divination The basic issue is really that nobody knows how this **could** work. Mostly this depends on how much advance warning you get. If only few seconds it is impossible to hide, if few hours or more nobody will never even notice you interfered to prevent something that never happened. For example, you could simply spend time with the boys so they never swim too far or go fishing with some other person who takes attention away from you when saving the boys. You can use your telekinesis to make minor repairs on things that would fail. To open a clogged safety valve of a fermetation vat, or to make a leak that lets out the pressure safely and forces replacing the vat. ## Headology You can mess with how people remember the events, right? Even without magic it is fairly easy to convince people that your idea was their idea. People take credit for ideas they like naturally without any urging. With magic to read people and make yourself less memorable there shouldn't be any real issue. Real world mystics and diviners can do some pretty impressive feats without a shred of magic simply by taking advantage of how people think. This is probably what Pratchett was referring with "headology", really. ## Evocation You can make things colder or hotter or cause electric surges to disable equipment without too much problems. Making things colder might for example slow down some process or make something more fragile. It would also be a good attack against people and animals when outside in a cold weather. It feels fairly natural and even a small drop will seriously sap your energy level as body will use as much energy as it can to prevent hypothermia. Hypothermia can also keep people alive longer in the right circumstances. Increasing temperature can also be an effective attack in warm environments for similar reasons. Temperature can be useful in opening stuck locks or doors. And being able to increase heat can be a life saver for people vulnerable to hypothermia. If you can cause large temperature changes in small areas you can unstuck almost anything and probably even disinfect wounds. Electric surges have obvious value in an age filled with electric devices. And electronics is vulnerable to even quite small surges if accurately targeted. ## Anonymity In large cities people can do quite a lot while remaining part of an anonymous background. As in example, your vulnerability is in people making connections between events that in separation are harmless. As long as you leave no paper trail when meddling this will be unlikely in a large city, if individual interventions are not noticeable enough to be mentioned to others with complete descriptions of that nice person who did not tell her name. ## Fade in the background If somebody or something else is taking peoples attention people will not even remember you were present. If you can act from distance and mess with peoples minds this will be easy. You can manipulate people to take the necessary actions and grab the attention. Make somebody else go fishing on that lake without even saying a word simply by tweaking the discussion they have with someone else. Make everyone forget you were there by having people skip mentioning you when first telling the story to their friends or the police. ## Make no patterns Do not repeat the same action until there is a statistical anomaly. Do not spread your name around in context of interventions. Vary your appearance enough to avoid creating an urban legend of a woman with red shoes or green hair or whatever. In a large city where people do not really know you these will be a big help. [Answer] The thing that trips you up here is what's [called bias.](http://en.wikipedia.org/wiki/List_of_cognitive_biases) Specifically: [Confirmation bias](http://en.wikipedia.org/wiki/Confirmation_bias) Confirmation bias basically means that if someone says out loud "She's a witch!" then they will see a load of evidence to support this theory. The events where her powers were manifest will stand out. It's actually very hard to avoid too - we have plenty of real world examples of witch trials where enough 'evidence' was secured to convict, despite such evidence only being allegation and confessions under torture. So I think what she would need to do is be extremely careful to act at a distance, and try and decouple the chain of events. People *will* notice her involvement in fortunate outcomes. This may be ok, they'll assume she's lucky, but they will notice 'something special'. We get winning streaks on a daily basis that look 'lucky' but are merely the result of humans being really bad at handling 'random'. So what would be needed is action at a distance and plausible deniability. Avoiding being present at fortunate events. Sabotaging things in advanced - maybe the brewer is called out of town at short notice because a family member is unwell (poisoned), and that's nothing to do with her... Healing done slowly and subtly - maybe outcomes are better overall, but anyone who makes a 'surprising' recovery will be treated with suspicion. This may, at extremes, mean letting someone die. But perhaps not - maybe it's possible to heal them slowly, and hiding the fact that naturally they *would* have died. [Answer] ## People Will Talk Even without any evidence at all, people will attribute positive (or negative) events to magic - even in a world where magic doesn't exist. A lot of positive events will undoubtedly cast suspicion. When something happens that is statistically unlikely, people are more likely to assume that the 'winner' was cheating. Hiding would mean not being associated with any suspicious events. ## Life in a Glass House Now, as long as everything always goes great, a witch would probably be safe. People wouldn't want to push their luck, so as long as everything was *always* good. Of course... it's almost impossible for everything to always go right. Sometimes, even magic can't cure a disease, or stop an accident, and when someone gets hurt, there will be no more safety net. It's probably already gone - that brewer may have kept his life, but he lost his livelihood. If the townsfolk are already talking, it's only a matter of time before the torches and pitchforks come out. ## So what now? To keep her abilities hidden, Rynn needs to become a con artist. She needs to practice the art of redirection, of covering her true intentions with something that looks plausible. The townsfolk have associated all those events with her because she was *there*. What Rynn needs to do is: * **Stay away.** If at all possible, don't be present. A thousand magical events in a thousand different situations (like a log magically floating out to the two drowning boys) are harder to put together than a thousand magical events with a single point of similarity. So, Rynn needs to stay out of sight as much as possible. If she were "out of town" while something happened, all the better. * **Redirect.** A lot of trouble can be avoided by simply not being there; however, instead of it being Rynn herself making sure no one is there, she needs to get someone *else* to do it. Perhaps the brewer gets message from the bank demanding a meeting, or his wife gets a bad cold so he's late to work; either way, there is no suspicion thrown on Rynn. * **Don't get greedy.** It's easy to want the best in every situation, but "the best" also stands out like a sore thumb. Instead of ducking when a rock it thrown, Rynn should let it glance off her shoulder. Instead of the thieves returning her purse, they just 'accidentally' lose it, and someone else returns it to her (at which point she cries about the missing money, even if there wasn't any). Bad things keep happening, just not as bad as they could have been. * **Have a reason.** Sure, Rynn's cookies cure kids; why wouldn't they? She puts some healing herbs from Farmer Brown's north pasture in them. Everyone knows those herbs cure anything. Instead of magically getting better, the kids get better because of *Science!*... even if it isn't science. * **Be friendly.** It's one thing to accuse a stranger or an acquaintance, but it's another to accuse a close friend. The more friends Rynn has, the more potential allies she gains; down at the pub, when two men start talking about "that strange woman," her next door neighbor can casually chime in, diffusing the situation. * **Ask favors.** This actually has two benefits; first, a witch can do everything for herself, so someone asking for help probably isn't a witch. And second, asking someone for a favor actually causes them to trust you more. ## Specifics All of this is, in the end, Headology. The more Headology, the better, in fact. If Rynn keeps tabs on the townspeople, and diffuses tension before it can build, she will stay safe. Telekinesis can be helpful for tiny nudges, but she shouldn't do anything obvious with it: untie a shoelace, but don't lift a boulder in the air. In fact, it would be better to use telekinesis to *stop* things from happening; no one notices when a rock *doesn't* roll down a hill. Divination is the key to staying out of trouble, too; the longer she can see into the future, the better off she'll be. She could even test several methods of helping people before she actually tries them. Evocation, on the other hand, would be dangerous, because it's highly visible, and almost impossible to pass off as a natural event. No newt-transfigurations or lightning bolts here! That's a sure-fire way to get your trial *after* your hanging. [Answer] Rather than answer all the questions posed I'm going to focus on one aspect of this question: > > How should a mage act to make him less likely to be detected? > > > They will have to let some bad things happen. Both to themselves, and to others. There are some actions they *could* take but even when people aren't magic, it only takes one or two coincidences for people to connect dots that may or may not be there, and call it witchcraft. Consider the Salem Witch Trials. No magic, and yet once someone claimed that their neighbor was a witch then others were willing to come forth to testify against them, having seen anomalies. Humans are *exceptional* at noticing oddities, coincidences, correlations, etc. Further, I don't think this is something they could do as a child and get away with it - in their youthful enthusiasm they would undoubtedly be discovered. Either the magic has to come very gradually once they gain enough understanding of the world to protect themselves, or they have to be trained by someone who knows their magic, or it has to be subconscious such that they aren't even aware that they are doing it, but still limited to avoid detection. Lastly, you couldn't call "entire town trance" subtle, and outsiders would quickly notice something wrong, so I don't think this would apply to your question. But it's worth some consideration if your location is particularly secluded. [Answer] *This is long, because I have had a great deal of fun exploring magic from an information theory perspective. There's a separator half way through for those who just want to read how Rynn should behave.* I would approach this from a key observation: others will observe the effects of Rynn's magic. If they don't, it makes for very poor magic. Something should happen. While it may seem like the secret to subtle magic is to make as "small" of a change as possible, a more precise wording is helpful: the secret to subtle magic is to do things in a way which is easily explained by The Unknown or to encourage others to not search for an explanation in the first place. In science, The Unknown is modeled as random variables. However, The Unknown takes on many forms in other approaches to making sense of the world. The Norse might call it Loki's mischief. I've heard it called the devil's handiwork before. Whatever you call it, it represents that of the world which you did not measure, thus cannot predict its effects. This approach is particularly convenient for modeling such subtle magic because it lends itself to an easy study using information theory. Assume we all have some information about the world. As we interact with it, we learn more. We also forget things which are of lower value (consider: the third letter of this paragraph is an 'i,' but you didn't think it was important enough to remember that, did you?) To elicit a subtle magic effect is akin to being able to see the world in a different way. Consider the subtle magic of a teenager fixing their grandparent's computer. The way the grandparents view the world is valuable in many ways, but in the particular case of computers, their worldview is highly ineffective at solving problems. The teenager, having grown up with computers, can easily see the root causes of computer related problems and find solutions. From the grandparents' point of view, what the teenager does is indistinguishable from a subtle magic. They simply cannot see enough information to explain why the teenager's approach yields success when theirs fails. All they can do is keep his or her number on speed dial and thank the stars that they don't have to solve these problems on their own. Such a world view can be viewed as a body of information itself. The worldview is made up of many assumptions and patterns that have been useful in the past for understanding the world with as little effort as possible. Being information, it can be shared. This is where our teenager's plight differs from Rynn's. While the teenager would certainly *love* it if their grandparents figured out how to work a computer, Rynn has a vested interest in not letting them do so. If everyone could see the world the way she does, then they could predict her abilities in advance and effectively nullify them. She needs to keep this worldview secret. This leads to what I would call the first rule of keeping magic: **Magic must not "leak" information about how it approaches the world, or it becomes commonplace, just as the magic of flight is now a daily commute for many.** So how do we avoid leaks. There are two fundamental techniques I can identify: * Don't emit any information. * "Whiten" the leaked information to make it appear more like The Unknown before emitting it. * Gather information that others do not know, and obscure the leaked information with it. The first solution is easy. If you don't emit any information about your worldview, you are safe. However, this is very difficult in the face of science. Science is very good at collecting multiple datapoints and mining them for data. The one escape: do magic only once. In many magic systems we see the concept of someone getting to do a "miracle," but often they can only do one. The idea is that each person has something that makes them "them." Nobody else has it. If you are willing to give it up, you can do tremendous magic. However, afterwards, everyone knows that little bit that makes you "you." With that information, they can identify how you did the magic, and it ceases to become magic. However, in the case of miracles, the effect is already done. It occurred too fast to prevent the first time; all the world can do is prevent it from happening again. The next two solutions both involve "whitening" the information to make it harder to discern from The Unknown. This process is easily seen in modern computer cryptography. Two individuals with a shared secret can communicate using an encryption which others cannot penetrate (such as AES). One way this can be applied to magic is if a founder of a magic school can split the magic into two parts which functions similar to public key cryptography. The founder breaks the magic into a public and private part. The public part is the one which does all of the work of magic, but it can only do it with the help of the private part. The private part contains the secret keys to the art shared only between those in the school of magic and the source of the magic itself (perhaps the universe). When "casting a spell," the inner part allows for an interaction with the source of magic which appears to be noise unless you have the secret key. The source then provides you the power needed to complete the spell using the public part of the magic. This pattern shows up in secret societies. When a magical group has secret rituals, they form the backbone of that inner "private" key. If you could observe those rituals, you could dismantle their power. They keep them secret. However, you see the outer "public" key, which is the powerful magics they wield (such as the ability to cause rain to fall). Of course this has two fundamental ways to fall apart. The first is obvious: if the secret rituals are exposed, so is the root of their power (akin to Sampson of the Bible having his hair cut). The second is more subtle: your power is only protected by how effectively your secret rituals *actually* guard your abilities. Consider the ENIGMA, which had the magical ability to protect German U-Boat movements until mathematicians in England figured out exploits to uncover the secret keys. Secrets get broken all the time. The final solution in my list is to acquire information which is not known by anyone else, and use it to "whiten" the magical information. This has a dark side and a light side. The dark side is visible in many magic systems: the ability to take information by force. Sacrifices and blood thaumaturgy are examples of using something which has never been exposed to anyone else and using that to whiten the magic. *Before going onto the light side, I'd point out the middle ground you will find between them: chance. If your magic works if a coin flip is "heads" and fails if the coin flip is "tails," then it leaks 50% as much information with each usage.* The light side is to use only information which is given freely. Secrets, promises, locks of hair: these are often given as "payment" for magic. These contain enough information to obscure the magic from the world, making it appear Unknown. The lightest of the light side is to use only information which is forgotten or left behind. Most people forget how many steps they took from the cab to the front door, or whether they turned the doorknob clockwise or counterclockwise to enter. This is enough to "whiten" very strong magic, so long as nobody ever catches on to how you're doing it. --- So let's get to Rynn. How does Rynn remain undetected. Of all of the methods of obscuring magic, the only one which is reliably undetectable is to collect that which is forgotten. However, we run into a bit of an issue: nothing is ever truly forgotten. Someone may forget their hat, only to remember it and come back later. If she were to rely on such forgotten things, she would eventually be trapped. There is one pattern that is demonstrably undetectable. Many interactions are not fully observable. Push on someone and it's hard to tell if they're just really light for their size, or if they helped you by moving with you instead of resisting. Shake someone's hand, and it is hard to tell if you are enthusiastic to meet them, or if they are enthusiastic to meet you; both cause the handshake to pump up and down the same. In these situations, each party only observes at most half of the information in total. The other half is free to be used for whitening. Now eventually someone will catch on. After all, you only get lucky so many times. Someone will eventually figure out what Rynn is doing if she's not careful. She needs a second layer of defense - one which your description captured perfectly. She needs people to *want* to believe she's just lucky. Accordingly, she needs to seek out win-win situations, where she benefits and the other party benefits. Hence the curious tendency for people to just get better around her. This would result in a tendency for people to begin to migrate towards her instinctively. Eventually people do realize there's something special about her, but if they are comfortable enough with that level of specialness, they wont pry. (Interestingly enough, this is a strong in-character corollary to Sanderson's First Law of Magic, "The ability for an author to use magic to resolve conflict is directly proportional to how much the reader understands it.") Now for actions. These are the interesting part. Consider that an ill-worded answer to a sharply phrased question could reveal a little of her magic. Too many such answers could box her in, forcing her to reveal more than she wants to. She would have a strong tendency to avoid giving answers to sharp questions - ideally by misdirecting away from them, but she would resort to vague answers if needed. Her actions would be similarly vague. If people are naturally attracted to her, she would need to be able to move agilely to avoid being smothered by them (physically and socially). The rest of society can help. Attitudes such as "do what you will, may it harm none" would allow much more room for Rynn to do extraordinary things without bothering people. Scientific thought would be the most difficult attitude for her to cope with. Scientists would constantly be trying to fix the variables she needs to whiten her magic. One strong sign of this would be people asking for repeat performances of previous magic (to which she would never do *exactly* the same thing twice. Each magic would be independent to the circumstances). A fear of The Unknown could result in a violent confrontation with Rynn, for her power depends on the ability to blend in with The Unknown. If it, itself, is hated, then blending in is much less useful. [Answer] Your background evokes a society full of superstitious folk, who would suspect magic even when it isn't there. So I think no matter what Rynn did, people in that town would believe she was a witch, even if they had no evidence, and in fact, probably even if she wasn't. They would want to protect her, to turn a blind eye, because she is kind and helpful, so she could actually get away with an awful lot - so long as it didn't harm people, or make it seem like she could read their thoughts or control their actions. Now, I was thinking into this kind of society, bound to suspect magic even from non-magical healings, you could introduce a character who explains everything with science. Someone who shows how the tricks are done (in fact, does those tricks themselves), and defrauds imposters. Someone with a Sherlock Holmes ability to read people, a medical background, an interest in mechanics, and a good head on their shoulders in times of great pressure. Working together like Penn and Teller, Everyone would be looking at the showy magician while Rynn was quietly doing the magic. Occasionally the magician "explains how it was done". In this situation - you could get away with EVERYTHING. [Answer] If you wanted a magic that was indistinguishable from luck but consistently in your favour, I think the magical ability you would need would be to see alternate outcomes of an event and to pick which outcome occurs. If you were to subscribe to the many-worlds theory this would be a matter of picking out which world you are in following any specific event. This is quite an interesting idea as a form of magic, guiding the world towards the outcomes you desire by nudging the causal chain of events that would otherwise fall out randomly. Perhaps there is a certain maximum probability beyond which someone with this ability would not be able to reach. It also opens the door for a certain irony in your storytelling- the ability to forsee the consequences of events in the short term might well lead to unforeseen consequences in the longer term and there would probably be greater risks with affecting causality more strongly, all kinds of butterfly effect style chaotic outcomes emerge on the cards. [Answer] The same way they audit casinos to ensure that the games are as-specified (I wouldn't call them *fair*). Adding up day to day events is fraught with bias. You need to pair events with those occuring to other people, and choose things that you can obtain clear results for, rather than fuzzy subjective judgements. Given that, statistics are well understood and used in science for that purpose. Seven sigmas is the standard for discovering the Higgs Boson, as opposed to coincedences and random jitter. --- But, by whatever means would be possible for normal, phenomena, her talent would work to prevent being discovered. If you were going to be suspicious, she would just happen to avoid you or you would start to miss seeing the events. [Answer] I love the idea that magic itself has a mysterious cognizance. That the protection afforded is not specifically controlled by the conjurer/subject, but by some other unknown force. Piers Anthony used that concept once: a character had the magical quality of silent protection; to protect itself, the ability prevented detection by others, through no action by the character. The character didn't even realize the quality existed for most of the novel. So, using the OP's example, Rynn would act to tie her shoelaces right then. Not because she knew the rock was coming, but because she just happened to notice and the timing was perfect. So I suppose that's a form of Evocation, but with a twist? [Answer] One interesting way to think of the magic would be the ability to sense and manipulate luck itself, with the caveat that she can't *create* luck, just *transfer* it. That would both explain the need to keep it subtle and why she can't just eliminate all traces. Perhaps without Rynn's intervention the fermentation vat accident would have severely burned the brewer, but done little damage to his property. She traded off the good luck of avoiding injury with the bad luck of extensive property damage. She doesn't stop the boys from going swimming in the first place, because that would require an unacceptable expenditure of bad luck somewhere else. The orphanage donation may have been made possible by the naturally-accumulated bad luck of the orphans. The sick children accidentally got caught in some crossfire of a luck transfer, so Rynn corrected it when she was able. The cookies had nothing to do with the magic, but were made by way of apology. The climax of the story could involve some spectacular feat of magic that everyone agrees is necessary, but comes at great cost. [Answer] If magic/witchcraft was real, then Rynn's brand of magic would be much closer to the truth than Harry Potter, or any witchcraft in popular culture. Is she really a witch, or just some crafty old lady? If someone snuck up behind her and threw a rock, did she know they were there the whole time and anticipate the rock being thrown, or did she really have magical powers? Maybe she really did cast a spell on the cookies to magically make the children feel better, or perhaps she used herbs or some other natural ingredients which made their little tummies feel better instead. The bottom line is that there should be some kind of scientific explanation for her actions. This explanation might not be immediately obvious at first, but might make sense with an explanation at a later date. In the Middle Ages educated intelligent people needed to stay away from the limelight or risk being executed or jailed. Religious dogma ruled far and wide, and intelligent people were persecuted by the church for heresy and witchcraft for simply knowing too much, or going against the norms of that culture. Throughout Europe during those times, much of the ancient knowledge was lost. It would take centuries to undo the damage done during this period. Countless books were burned, and scientific research came close to a standstill. Change was not embraced, and not much changed technologically during that period. Rynn could be a modern day throwback to the idea that there were still intelligent people in the Middle Ages, but they more or less kept to themselves for fear of persecution. She could live in an area in the Bible Belt that is very resistant to change, and she would rather keep to herself then deal with the locals. To keep people away, she could have built a reputation for being a witch. This could be a combination of strange happenings which are true and others which are made up stories to keep the people confused. She will always try to keep at least a few steps ahead of everyone else to keep this going as much as possible. Or.. perhaps she really is a witch after all. The choice is yours. [Answer] belated answer, consider adding a scapegoat. Something else that is 'lucky' and not Rynn. Have someone find something one day that is unique and convince everyone that it is lucky. Get them to believe that as long as they take care of the object good luck will happen, that they need to value it. When something bad happens to the object temporarily make lots of *minor*, nothing too harmful, bad luck happen around town. The sort of annoyances that stick out in our head but don't really do any long term harm. Then help everyone to do something to make 'right' whatever was done wrong so they can get their good luck back. This way people will associate the good luck with the object, not Rynn. Their own confirmation bias will ensure everything gets credit to the object. Now anyone who does have a tendency to think twice about their good fortune knows who's to blame and doesn't look for a second candidate. After awhile, once everyone has firmly decided the object is special, Rynn can claim to be helping to take care of it, and in so doing explain any good luck that happens near her is just the object acting through her to do bring good fortune. This is a general overview, there are lots of similar approaches to the same idea; the key thing is to give an alternate suggestion for the course of their good luck. She still needs to work indirectly, but she can get some additional leeway. The biggest way to make this work is to every now and then have something take away the luck if something happens to the object; but in a way where the townsfolk can easily fix the problem, so that there is a quick cause-effect relationship to confirm their belief the object causes the luck. [Answer] **Dilution is the solution to pollution.** Rynn does the magic stuff. She does lots and lots of other stuff too. She is active in city politics and in her church. She is a relentless volunteer and organizer. She attends rallies and protests. She coordinates public art. She advocates for her community at the state and sometimes even national level. She is not a loudmouth but she is everywhere - a fixture of the city. So when the kids feel better after eating her oatmeal cookies that is diluted out by the kid who got bit by a dog after eating her oatmeal cookies, or the kid who got picked up by the cops for shoplifting after eating her oatmeal cookies. It is no surprise that she helped those kids at the lake; it is not uncommon to see her there with her friends picking up the park or even going for a swim. Her magical deeds are diluted out in a sea of ordinary and even extraordinary deeds. It is possible that all her deeds are leavened with subtle magic. People chalk it up to her green eyes. [Answer] I would offer a two-pronged answer: 1: How many uncanny apparent coincidences could a character get away with? 2: Even or especially if she has unearthly charisma, she's in a danger zone; people at extremes of privilege can experience [Wagon, Blackbird, Saab](https://CJSHayward.com/blackbird/) effects. The beginning of [blackbird effects](https://CJSHayward.com/blackbird/), unlike the story is told, begin well, well, *well* before people say, "This has to be supernatural!" [Answer] There are a lot of very good and complete answers and I don't want to write a wall of text just to repeat what others have already said. Some have mentioned the need to divert (on a long enough time frame) attention away from her in regards to all the lucky events happening around her and the village. Obviously she doesn't want to stop being a witch (stop using magic) just to protect herself from bias and lack of understanding. But if she were to realize the danger of it, I think it would be fairly easy for her to cast the reason for the town's luck onto pretty much anything she wants. (An old tree in the village square was saved after some controversy and following the decision to keep it, an abnormal amount of luck occurred all over the place, etc..) **Symbols** hold great strength. And while the children might still whisper in corners that she does magic and all that, adults will easily dismiss them because the village is lucky because of [Insert event or Symbol, Statue etc..], not the sweet girl/woman who is so shy and caring. (How dare you accuse her of such a thing - nothing wrong with a magic fountain though.) ]
[Question] [ \*\*\*\*\* **Xenobiology expedition 'Profundity': Log entry 504** \*\*\*\*\* Glass Ants are a fascinating species. We discovered them on an arid desert world last visited by humanity aeons ago. They seem to have evolved from an Earth species into something unique. Glass Ants seem to have two interesting methods when it comes to preserving water. First, the insides of their nests are made of fused silicates, forming a water-tight seal that prevents moisture from leaching into the arid environment around them. The humidity inside such a nest allows for the comfortable gestation of infant ants even when the air outside is totally dry. Second, sometimes a caste of the ants that we haven't observed in any other species (we call them "doorway ants") wedge themselves at the mouths of tunnels to better seal the moisture into the nest. In extreme temperatures we've seen these ants sacrificing themselves in order to keep those within safe. The Glass Ant nests can extend for many meters horizontally; we recorded one with tunnels nearly a meter deep. Sometimes the wind blows the sand away from the top of the nest (a situation that would leave other insects in peril) but the Glass Ant nests protrude stably above the surface, a bizarre testament to the skill of their constructors. In these situations, Glass Ants have been observed entering and exiting through mid-level entrances, while doorway ants block up the exposed but useless entrances high in the air. The one thing that we haven't been able to work out: **how do the Glass Ants manage to generate or handle the intense temperatures required to fuse the sand into the shapes required?** We know they can handle some pretty high temperatures (they live in a greenhouse in the middle of a desert, after all), but we're not sure how they summon the thousands of degrees that must be required to create the nests... If anyone back at HQ has any ideas, we'd love to hear them so we can try confirm their behaviour. [Answer] Joe, this is the HQ. It's likely the ants do not really melt the glass. In the 20th century some material scientists on Earth developed a kind of [photoresist](https://en.wikipedia.org/wiki/Photoresist) (called [spin-on glass](http://www.desertsilicon.com/product-category/spin-on-glass/)) which, after exposure to UV or e-beam and curing, would become what is for all intents and purposes, glass: randomly arranged SiO$\_2$ chains. [![enter image description here](https://i.stack.imgur.com/HiUfM.png)](https://i.stack.imgur.com/HiUfM.png) The principle is fairly similar to that of epoxy resins, providing that Si atoms are present in the precursor molecules. We believe these smart ants must have developed the ability to secrete such precursors and trigger the curing via some enzyme. Like the Earth wasps that chew wood fibers to produce paper for their nest, these ants chew these precursors and use them to cover the walls of their tunnel, initiating then the curing. As bonus for them, H$\_2$O molecules are released during curing, which is a definite plus given the dry environment where they live. [Answer] They aren't really ants, they are **Thermites**. Your ants deposit a line of thermite in a new tunnel, then ignite it (bonus points if they use a glass lens and sunlight for it) after scrambling the hell out of reach. I'm not enough of a chemist to say how they'd produce the thermite, but nature will find its way. (Maybe they use some symbiotic bacteria?) [Answer] ## There are already organisms that secrete glass without high temperatures. This [paper](http://pubs.acs.org/doi/abs/10.1021/cr900334y) discusses a wide variety of ways organisms handle it: * Glass sponges grow a skeleton of glass spicules; * Many plants secrete tiny glass crystals called phytoliths to dissuade herbivores; * Diatoms and radiolarians secrete a glass protective skeleton. You just need the right enzymes or organic acids to dissolve the silica in the sand. Many ants use symbiotic bacteria or fungi so the ants could be spreading a different organism the secretes a glass skeleton. Or the ants could just handle it themselves; it would not be shiny clear glass, but you would not get that from melting the sand either due to all the impurities – see fulgurites or lightning glass. Secreted glass on the other hand can be shiny and clear if it is secreted slowly. Glass sponge: [![glass sponge](https://i.stack.imgur.com/KStDD.jpg)](https://i.stack.imgur.com/KStDD.jpg) Fulgurite: [![fulgurite](https://i.stack.imgur.com/XZM0M.jpg)](https://i.stack.imgur.com/XZM0M.jpg) [Answer] Joe: Some folks back at HQ have some doubts about the Glass Ants building these tunnels. Instead, they may be excavating them. [Desert glass](https://en.wikipedia.org/wiki/Desert_glass) is naturally occurring glass made when lightning strikes desert stands. The lightning fuses the silica together to form glass. Your Glass Ants may be finding natural deposits of this glass and then burrowing into it. This theory seems plausible especially since you note wide nests instead of deep nests. Now, the natural desert glass doesn't form long chains of glass. You get a lot of individual nuggets along the lightning's path. So, if this theory is correct, you should be able to check the tunnels for seams where the ants have joined two nuggets together and then drilled into them. On the other hand, the ants might be fusing the glass themselves by laying down naturally occurring aluminum deposits and waiting for a lightning strike. This would create long chains of the glass all by itself which the ants could then drill into, without seams. Consider that during the desert monsoon season, the ants have water, so they might just need a more conventional nest, and the wet sand provides enough structure for temporary nests. Away from that temporary structure, they lay out the aluminum paths. The lightning in this desert during a monsoon may be common enough that the ants can count on this as a construction technique. Once the lightning strikes, they drill in to create the permanent nest that will see them through the dry times. [Answer] **Glass ants use symbiosis with a native plant species (with hollow roots) that already used silica naturally (and without needing high temperatures.)** [![http://dvg4ol0hclm7o.cloudfront.net/content/royprsb/275/1649/2319/F1.large.jpg](https://i.stack.imgur.com/A6CiH.jpg)](https://i.stack.imgur.com/A6CiH.jpg) Three facts help explain the glass ants: 1. Ants species have repeatedly formed symbiotic relationships with plants (and fungi) for food, shelter and defense. Examples include: <https://www.sciencedaily.com/releases/2014/01/140115113243.htm> <https://en.wikipedia.org/wiki/Leafcutter_ant#Ant-fungus_mutualism> 2. Some plants naturally use -- and create/deposit -- silica. Examples include: <http://bmcplantbiol.biomedcentral.com/articles/10.1186/1471-2229-11-112> <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2759229/> **Note also that *hollow* plant structures are common, such as bamboo.** 3. Ants are already evolved to be *good* at creating/excreting organic acids and other active chemicals already (as in Formic acid, in ants' scientific name, Formicidae. Silicic acid and enzymes to manipulate it are thus (a little handwavium here, I admit) not too huge a bridge to span: <https://en.wikipedia.org/wiki/Silicic_acid> From silicic acid, it's a short step to 'water glass': <https://en.wikipedia.org/wiki/Sodium_silicate> from which glass can be made. The plants accumulate silica (and when doing so), produce silica-rich intermediates (like sodium silicate) that the ants concentrate and store see the 'honeypot' ants: <https://en.wikipedia.org/wiki/Honeypot_ant> Ants enter the root system, eat the nodes (places that block the hollow places) and concentrate/store the 'water-glass' in specialized 'water-glass-pot' ants, until needed for waterproofing/sealing/repairs. Then, using an enzyme (evolved from plant-to-ant) gene transfer, they convert the water-glass into homogenous, waterproof glass to line/waterproof the hollow stems. The organic matter in those stems remains (outside the hollow and glass lining) in many cases, cushioning the brittle glass. In return, the ants scavenge the terrain and bring rare, needed mineral grains to fertilize the plants -- and encourage more root growth in directions the ants prefer (such as toward sources of water the ants have discovered.) [Answer] My first thought was something like the answer from [ths](https://worldbuilding.stackexchange.com/users/33515/ths) The ants cannot produce the temperatures required from their own bodies but could construct something using materials which burn at a high temperature. My first thought was **Thermite** But that's problematic.There is no known biological system which can produce pure aluminum. Aluminum is pretty much absent from earth biology despite being the third most common element on earth. So making aluminum powder is biologically problematic. We also have a problem with ignition. You need burning magnesium or similar to light thermite. **Alternatives** Creating pure aluminum is unfortunately apparently almost impossible but there is an alternative that might be vaguely biologically plausible. Potassium permanganate + Glycerin This also solves the problem of ignition. These 2 react at any temperature near or above room temperature. **Vague plausibility** Glycerin is readily produced by a number of plants already. A symbiotic fungus could act as the colonies source of Glycerin which could also act as a food store much like honey. This helps us come up with a sort of coherent path for evolution as well. First the ants evolve a food storage class, much like [Honeypot Ants](https://en.wikipedia.org/wiki/Honeypot_ant). [![honeypot ants](https://i.stack.imgur.com/UJnsi.jpg)](https://i.stack.imgur.com/UJnsi.jpg) Next they evolve a system for suppressing the growth of some kind of bacteria or mold in their cavern walls. A caste of ants produces or consumes and regurgitates (perhaps again with the help of some fungus) a weak dilute solution of Potassium permanganate into the sand in the walls of their tunnels to keep them sterile. Now there's only one final step: Combining them. Eventually the ants evolve a behaviour where they coat the inside of a new chamber in thick permanganate. During the coldest nights larder ants enter or are carried and spew a thick layer of Glycerin on the walls and then retreat. The reaction does not start while the temperature is very low. Come the morning light starts to warm the sand. Around the new chamber it passes the critical point and the reaction kicks off. The walls start to glow and fumes billow out of any unblocked exits. A few moments later the reaction finishes and the walls start to cool into glass. Note that it would be a very dirty glass, not perfectly clear since some only partially fused sand would be stuck to it. [Answer] Diatoms are algae that make silica shells. They do not use heat, of course; they deposit hydrated soluble silica (as silicic acid) along with organic matrix to produce their shells. The shells last a very very long time. <http://www.pnas.org/content/113/8/2017.full.pdf> Having an ant acquire silica manipulating abilities is quite an evolutionary jump. It must not be easy given that no other shell-forming creature makes their shells out of silica except for diatoms. But ant colonies are known to acquire other creatures and incorporate them into their societies - an example is the fungus used by leaf cutter ants, which has been associated with the ants so long that there are no wild versions known to exist. Another example are aphids which the ants tend and protect in exchange for their sweet secretions. Your glass ants could have tame diatoms which they cultivate in a diatom colony. I imagine a diatom chamber where they are tended. Maybe it has a semitransparent roof to let in light which could explain the partly aboveground nests. The diatoms secrete a gooey amalgam of hydrated silica and organic schmutz which the ants use to glue grains of sand together in constructing their colony. This is similar to what termites do except the termites themselves secrete the goo, which is just organic glue and so not as durable as diatom goo might be. Since this is science fiction one could even make this diatom goo harden into opal, a gem comprised of precipitated soluble silica. That would make for pretty nests. As an afterthought I think the ants plugging chambers with their bodies is a nonstarter. Ant dies, dries, chamber is unplugged. Termites plug up their chambers too, for the same reason as these glass ants. Termites use dirt and rocks. [Answer] In addition to the excellent answers that provide a non-thermal method, you might consider a snap induced heat burst as used by [snapping shrimp](https://en.wikipedia.org/wiki/Alpheidae). > > The animal snaps a specialized claw shut to create a cavitation bubble that generates acoustic pressures of up to 80 kPa > > > ... > > As it collapses, the cavitation bubble reaches temperatures of over 5,000 K (4,700 °C). > > > I would imagine that as insects and crustaceans have somewhat similar construction it wouldn't be totally out of the question for an ant to evolve to use its mandibles in a similar way, possibly fusing one grain at a time with a rapid succession of snaps like a little MIG welder. [Answer] **Stained-glass ants** Some hypothesize that the ants don't actually create the glass, or burrow in glass, but actually *assemble* it. This world's deserts might naturally contain a high glass content (explaining some interesting aspect to the terrain), and the ants hunt down shards of this material, and line their tunnels. To add the structural integrity, they fuse the pieces with secreted resins, resulting in their tunnels, when dug up, having the look of a sculpture made of stained glass window. This is much more efficient for the ants than lining their tunnels with pure resin, as it doesn't sap nearly as much of their precious moisture. Locals, when looking to settle new areas of the arid planet, are encouraged to dig up small portions of a hill of glass ants (please use proper protective equipment). The ratio of glass to resin is usually a good indicator of how much moisture the area receives. If you see fine thin cracks, it's probably a lousy area to settle. If the joins are wide like the stained glass was made by someone with bad hand-eye coordination? You're in ideal territory (or a rainy season flood plain.) [Answer] # Lightning Ants Reading some comments and answers on here gave me another idea about how they do it -- and explains why glass ant colonies taken into captivity never seem to recreate their unique glass tunnels even in ample-sized sandboxes (pardon the pun): Lightning rods. ### Finding a place to call home When a new queen seeks to build a colony, she takes a couple hundred (maybe a thousand or two?) worker ants with her. They leave the nest at the first sign of precipitation; this has a threefold benefit: 1. The coming rains will ensure the queen and her "borrowed" workers stay hydrated while they seek an adequate location for a nest. 2. Rainfall is frequently accompanied by lightning storms... and this is how they start their new nest. 3. Once the nest has been formed, rainfall collects in reservoirs at the bottom of the nest to provide a source of moisture as well as maintain ambient humidity in the nest. As the first raindrops begin to fall, the ants use the flow of water to help find high ground (which also helps avoid drowning while they're excavating their tunnels). Once an ideal spot is found, some workers begin digging in the sand, periodically applying a thin layer of resinous secretions to help keep it from collapsing as they dig. While this resin isn't enough by itself to fully seal the tunnel for long term use, it adds structural enhancement and provides a key characteristic for the "solidification" of the tunnels... ### A conducive atmosphere Once they have the tunnels in place, the workers begin climbing atop one another at the entrance, forming a tower; these towers are estimated to reach nearly three meters tall\* and are easily the tallest objects in the nearby landscape. Having been freshly hydrated, their bodies are rather conductive, and thus "attract" lightning. The trick is that the resinous secretions are also conductive, so once the lightning strikes the "ant rod" it carries through the secretions along the tunnel walls and fuses the silica into glass, taking advantage of a natural phenomena to help strengthen and seal their home. Of course the ants that form the ant rod are killed in the process, but this provides a handy source of food for the remaining ants. It may not be the most nutritious, but it buys time for the colony to establish itself. The remaining ants will carry the burnt remains into the tunnels, and also scout them for any gaps that may not have fused. More resin secretions will be used to fill the gaps, and once cured is nearly as transparent and nonporous as the glass, while lending additional strength to the structure. ### The corker Similar to the *Cephalotes* genera of ants pointed out by @LoneBoat, the colony has a caste of large-headed workers whose sole purpose is to block the entrance(s) to the tunnel. In addition to providing defense and sealing in moisture, the "blockers" also serve to regulate water intake during desert rains. Most of the surface area of their head is a nonporous, chitinous material that serves as armor as well as a moisture barrier; most blockers have two to three small dimples in this barrier, and each dimple contains a tiny sensory receptor in its center about 100-200µm in diameter. This receptor lets them detect moisture, and they will unblock the hole when rains come so water can come in to replenish the reservoirs. As the water pours in, regular workers scurry down to the reservoirs to monitor them; once the reservoirs are nearly full, the workers make for the tunnel entrances and gently nip the blockers who will promptly return to their position and seal off the entrances so the tunnels don't flood. Once back in position, the blockers will refuse to move until their receptors tell them it's dry outside. While the colony will attempt to locate on high ground (improving probability of lightning strikes and minimizing flood risk) localized flooding can still pose a threat, so the workers will remain in place keeping the tunnels sealed. --- \* Individual worker ants are about 15-20mm in length, and the expedition's initial estimates suggest that the towers are comprised of 500-800 ants and the height and diameter is roughly relational to how many total ants the new queen was able to recruit. Naturally, more recruits means a taller and stronger tower, which improves the tower's chances of successfully getting hit by lightning to form their new home and thus improves the colony's chances of survival. [Answer] They can refract light within their bodies and concentrate it into a ray capable of melting glass and letting them work at a safe distance. P.S. I feel kinda disrespected. Isn’t this site all about brainstorming, or is there a difference to the distinction? I’m new, and want to hear some input from others. I asked for someone to give me an answer on how life would evolve on a sandy desert planet, and I get “CLOSED! BRAINSTORMING?! NOT FOCUSED ENOUGH!” A door just got shut in my face. [Answer] Following on from another answer about diatoms: diatomaceous earth, along with other types of amorphous silica such as that from geothermal springs, dissolves at high pH (13+). It then congeals into an extremely hard (but slightly soluble) sodium silicate body when frozen or dried, or into completely calcium / magnesium silicates if soluble calcium or magnesium salts (including hydroxides) are present. You can buy waterglass from a pottery shop and try it. There is also a solvent called catechol that complexes amorphous silica. Perhaps there's an enzyme with a similar complexing group on it that also transports the silica around the ants body, purifying it from non soluble components. That explains why the reprecipitated silica/Na silicates /Ca silicates turns out nice and glassy despite being made from dirty yellow diatomaceous earth. ]
[Question] [ *DISCLAIMER:* Any resemblance to other [starships](https://en.wikipedia.org/wiki/USS_Enterprise_(NCC-1701)) (living or dead) is purely coincidental. The starship 'Exciting Undertaking' is a brand new ship about to set off on a five and a bit year mission to explore mostly new lands and go where only a couple of people have gone before. As space is boring, it has wrap capability (no, not warp, wrap), and to relieve some of the mundanity of existence it also has Duplicators (like replicators but *completely different*) and Translocation technology (which moves people from place to place by overloading the Plot Buffers). The one thing it needs, oh noble starship designer, is a method to avoid any main ~~cast~~ crew member needing to leave for a [bathroom break](http://tvtropes.org/pmwiki/pmwiki.php/Main/NobodyPoops). As many suggestions as possible are needed to make sure that there are multiple redundant systems in case something new needs to break in an entertaining and mildly perilous manner. [Answer] # Recycling via Teleportation The ship's medical computer continuously scans the pressure on every ~~cast~~ crew member's bladder and rectum. As soon as the pressure reaches a set level, the contents are immediately (and almost painlessly) teleported directly to the food replicators. As illustrated: [![enter image description here](https://i.stack.imgur.com/9HlcB.jpg)](https://i.stack.imgur.com/9HlcB.jpg) (any resemblance to currently or past serving starship officers is entirely coincidental) Quite neatly killing two birds with one ~~turd~~ stone. [Answer] The ultimate expression of *Translocation technology* would be to simply eliminate much of the starship and carry the people as patterns in the buffer assembly. Once the plot location has been reached, the computer *translocates* the ship's heroic crew members and a few selected Redshirts to the location, so they can carry out their assigned roles... The advantage of this is when the crew is *translocated* back aboard they can be stored in the pattern buffer, and "edited" so they will be fully loaded with glucose and whatever other life sustaining chemicals and nutrients are needed for their species, medical damage repaired (i.e undoing broken bones, removal of disease organisms) and of course waste products are removed both in bulk and at the cellular level. The conscious and unconscious memories are downloaded into the ships permanent memory storage for editing and post production work... The starship will no longer be an aircraft carrier sized construct full of open spaces for the crew, but more likely resemble a server rack with lots of external hard drives or flash drives attached. [![enter image description here](https://i.stack.imgur.com/WyLFj.jpg)](https://i.stack.imgur.com/WyLFj.jpg) *The only sinks we need here are heat sinks* Of course, depending on the plot elements involved, the amount of energy you are willing to expend and so on, even a very modestly sized construct could be used to *Translocate* entire armies onto a planet. Translocation technology is such a mind blowing concept that was never fully explored. Even this little post only scratches the surface of the possibilities that *translocation* offers. [Answer] Your duplicators may be capable of supporting the crew's dietary needs on this new advanced starship, but we didn't always have things so easy. Humans are incredibly inefficient creatures, and messy ones at that. In the earlier days of space travel, carrying enough supplies to sustain a crew on extended deep space missions was a serious challenge. People fussed about with hydroponics bays for growing food, atmosphere recyclers and waste re-processors, but as ships got bigger and missions got longer, all these complex systems became a major headache for systems engineers. Nobody wanted to design space toilets when they could be testing the next-generation of wrap engines! If only they could just fix the pesky humans that were at the heart of the problem, and make them less messy and inefficient in the first place... And then, eureka! It was invented: the solutions to all of 22nd century Earth's interstellar sanitation problems. I present to you, the C.A.N.: the Contained Abdominal Network. This brilliant piece of directed-evolution technology not only eliminates your need for elimination, but also decreases your food and water requirements. It works by culturing a special strain of genetically engineered bacteria in special capsules throughout your gut. To these wee beasties, one man's trash is another bacterium's treasure. In exchange for what is, to them, the perfect habitat, they metabolize human waste into useful nutrients, a fraction of which they recirculate into the bloodstream. After a few cycles through the C.A.N., there's nothing left of the body's natural waste but good old fashioned methane gas. Additional measures may need to be taken to compensate for the increased volume of gaseous discharge. With the C.A.N. managing your bowels, you'll be more free than ever to explore the cosmos efficiently and cleanly. Now offering free insertions for all crews! It won't hurt, we promise. [Answer] ## Just Use TP Why not use the TP like everybody else does? Oh, you might not realize TP stands for "teleportation portals". They are simple and friendly to use--just insert an ergonomically delightful portal device into any orifice that might offend and *voila*, no more trips to the bathroom! In no time at all the whole crew can be ready for a full episode of bathroom-break-free entertainment! TP is [clinically proven](http://images.clipartpanda.com/happy-face-clipart-excited-smiley-face-clip-art-i11.jpg) to be safe, friendly and easy to use. Even lactose-intolerant Klingers-On can breath easy with TP caressing their innards. "I've never felt so confident in my whole life!" - *Wharf, buttermilk lover* "Crew productivity is up 13.5% now that TP is standard issue!" - *Captain Smirk* ***Go Boldly With TP!*** [Answer] ***SPOILER ALERT!*** The entire crew are robots... *but they don't know it*! (*Of course a "spoiler alert" is a well known Confederation signal to indicate galley stores are nearing their expiration dates, not to be confused with an attempt to alert the reader that there are plot spoilers ahead, because this is information about a totally real starship. Sorry, I see how you might have been confused there, but the milk is about to go off and the crew does like to have cereal in the morning.*) Any civilized race that's gotten the need to climb and plant flags on things ["because it's there"](https://en.wikipedia.org/wiki/George_Mallory) knows that dragging your meat bodies around in space involves a lot of pesky extra weight and plumbing and all that food and water and air and... you know. It's much cheaper and more efficient to send robots. But robots are, well... robotic. They can't be expected to handle the unexpected. They can't know what it's like to have feelings, to wonder, to... ***LOVE!!!*** And that leads to the endemic problem of robotic space depression on long, lonely missions. Instead, as an outgrowth of the virtual reality video game and automated call center industries, the Confederation has created AI so nearly human they respond to exploration scenarios as a human crew would 67% of the time. 32% of the time they do better. And 1% of the time they explode. (*All Confederation technology explodes in a shower of sparks and fire when damaged or confused to avoid capture by the enemy. Don't get a flat in a Confed car.*) The trick is the AI thinks it's real, right down to emulating human fears, and psychological and physiological problems. They have "doctors" who wave glowing devices over their bodies, or prescribe pills and shots, that do nothing but transmit the signal for self-repair. All to keep the AI's construct of being a real human intact so they will behave like a real human. This is why Confederation "crews" behave so eerily perfect. Emotions that would negatively impact a five year mission in close quarters are toned down, while ones that would help are turned up. Emotions such as feelings of jealousy, post-traumatic stress disorder, independent goals, and annoyance are reduced. Comradery, optimism, obedience, duty, and sharing are turned up. Everyone is happy to wear the same clothes and do the same things day after day after day after day after day... Sometimes this is taken a bit too far. AI that have been away too long start speaking of an idealized society that doesn't need money with no fighting or poverty. These sad cases are nonetheless allowed to continue in their duties to spread positive Confederation propaganda. [Answer] ## **Multipurpose Elimination Room** As everyone knows, space is at a premium on space ships. (no pun intended) Why would you commit a section of everyone's quarters to take up an incredible amount of precious costly space? You need a multipurpose room that can be a toilet when you need it and a jazz club when you want to get funky with your trombone. Enter the holodeck! As a bonus you can rig up fantastic direct mind stimulation games so you don't need to play snake on your tricorder. [![enter image description here](https://i.stack.imgur.com/frnml.jpg)](https://i.stack.imgur.com/frnml.jpg) [Answer] No toilets because of some sort of... **Active recycling matrix** - standard issue, compulsory. Two types - partially inserted or close quarters. Waste is eliminated *at point* - the crew are free to relieve themselves with all but a few molecules being instantly captured and transformed into photons. An occasional flash of light is all. [Answer] # I. Improved food Finally, they are here. The nutricapsules are scientifically designed to be 100% absorbed by the guts, leaving no organic rests to be "disposed of". This allows your spaceship to store enough food for the mission in just a few modules, with no need of the extra weight associated with traditional food, as: * food that is only useful in 25% of the weight (if lucky). * facilities for storing the food and/or grow more. * facilities for waste treatment (including WC) and recycling. Some minor inconveniences are the adaptation periods before and after such a diet, to train again your digestive system to deal with traditional food. # II. WC at battle stations If the objective you are after1 is ensuring that nobody leaves their post while they are on duty due to "technical emergencies", then the other way around is make *everything* (at least in control positions) a WC. Technical suits have the appropiated *"connectors"*, both to the wearer's body and the control chairs, allowing a unconspicuous, odorless and silent *"emergency evacuation"*. While most astronauts prefer the solution with pill foods and think of this solution as a solid #2 (if you get what I mean), more than one has found this method surprisingly useful when fighting against overwhelming numbers of flesh-eating Zampas. # III. Surrogate crew members Space travel is long and dangerous, and a body subject to it will suffer greatly if not properly protected. But to be effective, regular work in unsafe places of the ship is required, and robots are just not effective enough yet. So the crew members are safely stored in a semi-stasis state, with their body functions unoperative until it is time to end the journey. Their mind, though, is fully functional and is wired, through the ship systems, to a robot "crew member" that he will direct with his thought. To improve control, the robot will be anatomically very similar to human. While functional, this arrangement was object of some criticism due to the long, long hours of boredom while the robot work was not needed. In an effort to alleviate them, the last generation of robots has been granted the ability to drink beer and has had some modifications done to the body, adding to the design certain parts that were left out from previous versions due to their lack of perceived usefulness and a certain degree of puritanism by the builder. --- 1It is not clear from the OP which is the author's intent. [Answer] I suggest creative use of the duplicator: when a crew member feels the need for a bathroom break you throw her/him overboard and replace him/her with a duplicate that's identical except for an empty bladder/stomach. [Answer] An option is to have 'waste collection' incorporated into the suits/uniforms worn by the crew on the ships. You could even go as far as giving the waste a purpose. (On board agriculture which needs nutrients, nutrients abundant in human waste). This also solves the problem of your crew visiting a planet that prohibits them from taking off the suit (toxic atmosphere/radiation hazards). And it could set up with entertaining/mildly perilous situations when the system is at capacity and the crew member has to go. [Answer] Temporal bifurcation closets (TBC). These toilets, present on every starship, are always meticulously clean. Firstly because of all the other systems available, but secondly because no-one ever actually uses them. At least the second time around. When a crew member needs to relieve themselves they will go (as you might expect) to the TBC. Once their waste is deposited the TBC will rewrite the history of the waste, right back to it's creation in the ~~repli~~duplicators, ensuring that the crew member never needs to go in the first place. "But!" some of you may cry "Then surely the crew member never ate at all! Also Paradoxes!" At which point you may be reminded of the well Known [Tennants Timey-Wimey-Ball effect](http://tvtropes.org/pmwiki/pmwiki.php/Main/TimeyWimeyBall) and directed to the nearest Starflotilla Educational Institution. [Answer] Having once been dumped in a peacetime military, I discovered two things. Firstly, stress makes you *need* to go, and army food tends to... clog up the pipes, so to speak. Considering mass is at a premium on any space ship, I'd propose that food on a starship would be high energy, low mass food, low volume that *expands* to be filling, and takes a very long time to digest, and does so with minimum waste matter and maxium caloric intake over an extended period of time. Once digested, the food goes back to its original low volume, reducing the need to find the ... comforts of the throne of thought as often. Since there's no real volume of food, there's nothing to output in times of stress. This in turn reduces the need for toilet facilities, while maintaining a happy healthy workforce, with only a slight chance of sudden violent diarrhea and painful death. Both these result in greater efficiencies, since you can store the food in smaller spaces and need less space for post consumer food. [Answer] **Being a crew member is a very "exciting" undertaking** While there are advanced scifi explanations for why will evolve beyond the need to poop, there is also a simpler and more low-tech explanation. Anyone who smelt the air in Victorian era London would know that a need to poop does not imply the existence of toilets. Perhaps instead of being a shiny cybernetic utopia, the future is *literally* a crapsack dystopia. Every week civilian starships with boring names like "The Enterprise" meet aliens that are about to destroy the universe, galaxy or at least the ship. This is no regular starship, this is the *Exciting Undertaking* which faces annihilation at least ten times every hour long episode. When friend computer designed the ship it forgot that meatbags nee *understood* that the highly valued human crew would be terrif *excited* by the suicida *bold* mission on which they were sent. As such the crew would vacate their waste product storage organs quite frequently during their insa *regular* duties. As such the death tra *ship* is equipped with diapers *crapsacks* and brown trowsers rather than toilets. [Answer] 1. The crew are [surgically altered before launch](https://i.stack.imgur.com/EvF1a.jpg) to have larger internal cavities for waste storage. They no longer have urgent needs to go to the bathroom and can stay on duty for as many days as modern future drugs can keep them awake. Waste evacuation can happen whenever the plot needs them to leave their stations for other purposes. 2. The crew are [surgically altered to connect their insides to their outsides](https://i.stack.imgur.com/xJg5l.jpg) [WARNING, PSYCHOLOGICALLY ICKY, BUT NOT ACTUALLY GORY]. When necessary, they can 'plumb in' to a drainage system. [Human precedent](http://www.livescience.com/28996-hole-in-stomach-revealed-digestion.html) exists, and that's because I don't want to link or consider the genuine human precedent. 3. Part of the spaceship exists in subspace, hyperspace, another dimension, a phase shift. But not the left half or the right half or the top half - the *bottom* half. People below the waist, their feet, the floor, are out of sight, out of smell and out of mind. 4. People have iPads gone mad. They do need bathroom breaks but it doesn't mean they abandon their duties mid fight, since the duties can be brought to the bathroom with them. [Holoportation](http://www.geekwire.com/2016/microsoft-research-star-wars-holoportation-hololens/) so the crew still see them sitting at their original posts is an optional extra. 5. The crew doesn't eat. Like Sam Rockwell in the film Moon, there are endless clones. They wake up, live until they die of dehydration, are disposed of and replaced with a clone. No food, no bathroom break. Very Matrix as well. This point has the advantage that it fits your "no bathroom breaks" clause to the letter, while not fitting the spirit of "no interruptions to a long situation", which is a perfect nitpick ;) 6. The crew doesn't eat, but for a much more mundane handwavy reason: nanobots. Yes, their bodies contain more nano than an entire series of Mork and Mindy, and that fixes the problem. How, you ask? Shutup, are you saying there's a problem nanotechnology can't fix? Do you wanna fight? 7. They are [Borg-style](https://i.stack.imgur.com/UIIU1.png) human brains but supported and animated by non-biological matter. Cyborgs, robo-bodies, mechanical life support systems, they're not really people at all. Before launch their bodies are put into suspended animation. Electric life is introduced, it runs in the pre-existing neurological patterns in their brains, like a tram following a human-behaviour-shaped tramline. Shadow humans mimicking the bodies they exist in; stasis-bodies have no muscle control, but they can be animated by the ship's internal tractor beams like a futuristic stop-motion. From the outside, you'd never know the difference. 8. Wow, did you say no bathroom breaks? Because I totally didn't just go to the bathroom. You can tell that I didn't go just *then*, because [no time passed between when I was just here, and when I am still here](http://harrypotter.wikia.com/wiki/Time-Turner) so there isn't even a '*then*' for you to be referring to. [Answer] The ship I’m designing for a (hopefully) novel does not have toilets. It’s simply a special case of not having *any* “life support” overhead for creatures like us. It’s crewed by post humans existing as software and is a completely solid structure. More generally, your crew is not beings like us. They don’t have the concept of a toilet. After all, we don’t do anything special with all the CO₂ we exhale — maybe they are like clams which don’t need to go off somewhere to pee, or like oak trees which simply don’t eliminate waste in such a manner. Maybe they digest externally and leave behind inetable parts when they pull their stomoch back in, or [suck out the juces from a carcass from which they previously injected enzymes](https://en.wikipedia.org/wiki/Spider#Feeding.2C_digestion_and_excretion): they have leftovers, not poop. [Answer] **Nanobots make your clothes functional, especially for this purpose** They are incorporated in the underwear which looks a bit like a diaper from inside (only much smaller and more fashionable) but instead of just taking up the waste and storing it the nanobots immediately transform it into nothingness just producing a nice odor (roses or so) and some heat (second law of thermodynamics if this still applies). Everyone is used to it from birth on. That's why it's absolutely normal. [Answer] # Instead of toilets, modern spaceships have "Head" rooms. Which serve the same purpose. Sources (detailing this for totally different, yet surprisingly similar spaceships): <http://www.cracked.com/article_24170_9-hilarious-background-details-star-trek-nobody-notices.html> <https://books.google.ca/books?id=ge_QJ2eM3KcC&pg=PT16&lpg=PT16&dq=star+trek+the+next+generation+door+labelled+head&source=bl&ots=DQukMMl3ud&sig=5INOOI2cJM429uTPNrFRvkgI4eM&hl=en&sa=X&ved=0ahUKEwjzwqeYqrTMAhWDWD4KHZ1SBqwQ6AEIRDAJ#v=onepage&q&f=false> [Answer] Bathrooms are not needed because of the way food is delivered. Inside their uniforms they have dispensers which have sensors to detect activity levels and consumption. They exact measure and inject the right amount of nutrients into the blood stream, bypassing the whole digestion process. For liquid waste products we would have catheters and vagina cups connected via hose down through our pants legs into our shoes. The bottom of the shoe would have a connector which would seamlessly connect to port in the floor that could be placed anywhere. Of course under their stations where the sit on the bridge, in front of turbo lifts and anywhere else it was convenient. Of course the system would automatically clean and sterilize all tubes as necessary. Everyone lives happily every after, except.... This is the USS Exciting Undertaking and not the USS boring. On our ship mysterious malfunctions (tricksters), have offered incentives (bribed) the right people and learned about certain vulnerabilities (Darn that ***password*** was never changed). People would randomly be flushed with hot, and then cold flushing, sterilizing, and fluids. Hey aliens need to go to, and so the system will have to offer a wide variety of customizable options. Pranksters (crew members) would accidentally (shove) bump others on to the connection points in the middle of conversations and speeches for all kinds of laughs. A secret point system would evolve to rate the cleverness, and the shock on the persons face when they got hit. Of course some might get reported, but due to other malfunctions the reports will be sent at sub light speeds and get back to earth(home base) long after it was too late to do anything about it. Now about the showers..... ``` **password** add lotion xxx alias required anti-bacterial wash. <new password> <lock> ``` sure got Exciting around there. [Answer] **Matrix Squiddies are the answer** [![enter image description here](https://i.stack.imgur.com/sTCx3.jpg)](https://i.stack.imgur.com/sTCx3.jpg) Miniaturized versions of these lovely robots roam the command bridge of the Exciting Undertaking. The tentacles of the squiddy have an aspirator device on their tips, while all the uniforms dressed by crew members have a comfortable rear flap. So, through the flap the squiddy can access the person's orifices with its tentacles and empty all the biological waste inside! [Answer] Humanoid robots would be made that need waste for energy (<http://mashable.com/2012/11/29/ecobot-iii/#kRXzS7kdlgqg>). They would then be programed with the emotional need "mate" with the crew, acquiring material they need to live. The importance of not letting your other crew members die (robots would be sufficiently advanced to have a personality), paired with the embarrassment of making a mess, should make it feel natural - turning a boring almost negative task (getting rid of waste, waste of time) into a positive (giving life). Further, crew may be paired with robot counterparts, or they may even be proactive in helping the crew - scanning a person, they would then approach them and say "May I relieve you of your duties?" - This could happen on the spot if needed and no interruption of work would happen. [Answer] With environmental control and force fields, they don't have to protect them selves against the cold, or injuries, so your crew is naked all the time, or their uniforms have but flaps, if some decency is to be maintained. The floor is laid out with straw. When a member of the crew, maybe a centaur had to go, robots exchange the straw at that place. The used straw, along with the waste is turned back into energy by the translocator and new straw is duplicated. There would be ways to deal with a 0G situation, but I encourage you not to think about them. This allows your crew to **boldly go where no one has gone before.** [Answer] **To take a dump where no man has dumped before:** There are no toilets, but there are force-curtains (which are like force-fields only not) everywhere, whenever somebody needs to go he just walks up to the nearest window and leans his butt against it, this activates the window transform sequence which then proceed to wrap around his butt and senses whenever something comes out of it, that something then gets passed through the force-curtains to outerspace. ]
[Question] [ So when I say everything, I mean *everything.* Humans, animals, plants, fungi, bacteria, all dead. If the bacteria and other detritovores and decomposers can't decompose anything since they themselves are all dead, what happens to all the carcasses and remains of the life? **Do these remains decay through other inorganic means? What do they look like throughout this process? And how long would it take?** (For the purposes of this question, let's just say that Viruses and Prions count as "alive", they are "killed" in this scenario as well) [Answer] **They weather.** [![seal mummy](https://i.stack.imgur.com/3AAaw.jpg)](https://i.stack.imgur.com/3AAaw.jpg) <https://www.livescience.com/18343-seal-mummies-antarctic-microbes.html> Antarctica has dry valleys where, for some reasons, seals sometimes went. It is a bad place for seals, and they died. It is a bad place for microbes and everything else too, so the dead seals did not decompose. These mummies are hundreds of years old. The mummies weather in the elements. UV radiation breaks down tissue. Wind and windblown grit wear it away. It is much like what happens to wood left outside in a dry environment. In a world without scavengers, fungi or microbes, these processes would be what gradually took away the remains of the world's life. I do not think warm circumstances would matter as much in the absence of life. Wet would matter but much less than it does when there are fungi - the water would carry away degraded bits as the rain washed the mummies - so they would vanish faster than these seal mummies in the dry valleys. [Answer] The remains would mummify, petrify, erode, and eventually become just another mineral layer. Where water is available the organic remains will dissolve and be replaced with inorganic minerals to form fossils, and if no water is available the remains will desiccate and be preserved as mummies. --- There wasn't much specification regarding the timeline or location, so the below are just the general process that will occur over a long period of time. **Mummification:** In particularly dry areas like deserts or mountain peaks, the remains would [mummify](https://en.wikipedia.org/wiki/Mummy), much like [this creepy fellow](https://en.wikipedia.org/wiki/%C3%96tzi#Tools_and_equipment). Even with regular decomposition mummification can still occur naturally, so without scavengers and bacteria getting in the way much of the life in dry areas would desiccate and mummify. **Petrifaction:** In areas with water, the remains would [petrify](https://en.wikipedia.org/wiki/Petrifaction). Water would leak into the pores of tissue and bone, and minerals within that water will precipitate out and saturate the remains, resulting in a combination of organic and inorganic remains. This process is called [permineralization](https://en.wikipedia.org/wiki/Permineralization), and is the reason we have dinosaur fossils. Without bacteria, the soft tissue remains would also go through this process and become fossilized. Over time, much of the organic remains would slowly be dissolved by water and replaced by minerals, in the uncreatively named process of [replacement](https://en.wikipedia.org/wiki/Petrifaction#Replacement). Unless the fossilized remains reach a dry area, they will eventually lose all of their organic components and be no different from oddly shaped rocks. **Erosion into Mineral Layers:** As explained above, the organic material in the remains will slowly dissolve and be washed away by water(and probably other chemicals). The dissolved bones, shells, beaks, and corals of the trillions of dead will pile to form [layers of limestone](https://en.wikipedia.org/wiki/Limestone), rainforests will turn into [vast swaths of coal](https://en.wikipedia.org/wiki/Coal#Formation), fossils and mummies would be formed in amounts to put previous [extinction events](https://en.wikipedia.org/wiki/Extinction_event#Major_extinction_events) to shame, and the swarms of dead ocean critters won't even [get to become oil](https://en.wikipedia.org/wiki/Petroleum#Formation) without bacteria. If given enough time, even the petrified and mummified remains will erode like an other rock, leaving little evidence of life except layers and veins of organic minerals. [Answer] Unless you totally destroy all proteins everywhere, I'm going to bet that some of the very simple forms of life will find a way to recombine after 'death', and rapidly turn the earth into bacterial soup. Most theories of the beginnings of life involve rogue proteins teaming up to eat other stuff, and I suspect some simpler single celled organisms would spontaneously do this right away, given the incredible abundance of defenseless, energy rich raw material all over the place. [Answer] Things would still decompose, but maybe not as fast, dependig on environmental factors. Enzymes and other chemicals found within the (now dead) bodies (or whatever remains) would break those down. Then of course there is heat degradation. And depending on environment (again), interaction between chemicals from both the remains and the environment. And then there is weathering. [Answer] In addition to @Giter's excellent answer, there is another destructor of life remains on land: **Fire** Wildfires will not only burn down the dead forests and grasslands but also consume almost all the corpses lying on the earth surface. The ashes will be dispersed by the wind and deposited somewhere, forming a faint geological mark of the end of life as we know it on earth. [Answer] Another solution: aliens. Well, kind of. I am assuming "everything alive in this world" means to a certain height above the earth, probably to the generally accepted limit for our atmosphere. We know for a fact that there are organisms hanging out on most if not all of the sundry items we have put in orbit around our planet. As those deorbit, some of those organisms will probably survive, and start feasting on the lovely food laid out for them on the planet below. It will take some time, but they will likely dominate the earth. [Answer] This is only a partial answer. Life is essentially an on-going chemical reaction. Killing all life does not stop all chemical reactions, it merely interrupts the reactions needed for life to sustain itself. Lifeforms contain many different types of chemicals/compounds. Some compounds are fairly volatile and would break down by themselves into simpler chemicals after a short time (hours/days). The stomach acids of animals would partially break down the body until they were too diluted to be effective. Some compounds would dissipate, such as water and oils in a dry environment. If the remains were in water, they would absorb water until an equilibrium was reached. The tougher tissues (wood, bones, spines, etc.) would last longer than the softer tissues (leaves, skin, blood, etc.) The more active the environment was, the more weathering would have an effect. After a short time, exposed remains would be subject to erosion and buried remains would be subject to fossilisation. Note that generally speaking, fossilisation is hard to achieve because so many factors have to be present at the same time, although with no life to consume the remains there would be a slight increase in burial events. Any remains in cold areas would be preserved longer than in hot areas because heat accelerates chemical reactions. [Answer] CJ Dennis is heading in the right direction. Chemical reactions keep happening, and life catalyzes some of them more than others. There would presumably still be lightning strikes, and eventually most of the dead forests and dead grasslands would be burned to ash. The existing coal mine fires would continue until they got buried or soaked. The main reason the CO2 level in our atmosphere is so small is that plants keep removing CO2. So CO2 levels would rise. But there isn't enough biomass to bring oxygen levels down very much. I think. Volcanoes and hydrothermal vents release sulfur gases and ammonia. If they weren't metabolized what slower chemical reactions would they get? It's hypothesized that the atmosphere used to be anoxic, and life created all the free oxygen. Maybe we could eventually get back to that? I don't think the numbers add up on it, I think there's far more oxygen than carbon biomass, but I could be wrong. Still, whatever equilibrium it approached would surely have much more CO2. It might have less N2 and more other nitrogen compounds, or maybe not. Nitrogen compounds are heavily metabolized and N2 is a low-energy form that some bacteria produce when they extract energy from other nitrogen compounds. Would we get a big greenhouse effect? I'd expect so. Pretty much everything that's biomass now would eventually get oxidized. The earth would have a very different climate, but it wouldn't be easy to predict just what it would be like. One reason to think it wouldn't just slip back to what we had before life changed it so much, is that the earth is not nearly as hot now. [Answer] This happened on earth several hundred million years ago: lots of oil fields will form. edit: unless there is no volcanic activity, in that case it will just lie on the surface. If there is an atmosphere, they will be eroded into microparticles. If there is no atmosphere, should just sit there forever. [Answer] ## This already happened in Earth's history This question has a very simple answer. Read this article: <http://phenomena.nationalgeographic.com/2016/01/07/the-fantastically-strange-origin-of-most-coal-on-earth/> That is what would happen. **To summarize in case you did not read it:** There was a time in Earth's history when, for millions of years, you had trees that lived and died but there was no bacteria that could decompose them. This was because the trees evolved before the bacteria that broke them down. What happens is that you get dead organisms piling on top of each other and crushing the earlier dead ones underneath. This compresses them into various natural resources that we use today (or in your case future intelligent species might use). You also get spectacular forest fires that last years or decades as there is just so much fuel to burn once a fire starts. Adding a few dried up dead animals to the mix, I'm sure, wouldn't be any different than the piles of dead trees that existed in the past. So what would you get? Oil, diamonds, fires, and some other resources. From Wikipedia: <https://en.wikipedia.org/wiki/Carboniferous#Terrestrial_invertebrates> > > The large coal deposits of the Carboniferous may owe their existence > primarily to two factors. The first of these is the appearance of wood > tissue and bark-bearing trees. The evolution of the wood fiber lignin > and the bark-sealing, waxy substance suberin variously opposed decay > organisms so effectively that dead materials accumulated long enough > to fossilise on a large scale. The second factor was the lower sea > levels that occurred during the Carboniferous as compared to the > preceding Devonian period. This promoted the development of extensive > lowland swamps and forests in North America and Europe. Based on a > genetic analysis of mushroom fungi, it was proposed that large > quantities of wood were buried during this period because animals and > decomposing bacteria had not yet evolved enzymes that could > effectively digest the resistant phenolic lignin polymers and waxy > suberin polymers. They suggest that fungi that could break those > substances down effectively only became dominant towards the end of > the period, making subsequent coal formation much rarer. > > > Reddit thread: <https://www.reddit.com/r/todayilearned/comments/29jltf/til_on_earth_there_was_a_time_when_forests_didnt/> ]
[Question] [ Mechs are really just giant usually bipedal walking tin cans with their human pilot inside. I mean, shoot the legs and they can't move much anymore. Not really realistic. Regardless, in a futuristic world where for some reason mechs are the main fighting forces supported by infantry and air forces, why would the mechs ever use melee weapons to fight other mechs? I have seen and read a few novels and games where they have mechs where a melee weapon[chainsaw, giant sword, lightsabers etc etc etc] was prominently used instead of a ranged weapon. Like the reason to have mechs would be to act as giant walking artillery units right? They need to be big to carry their equally big weapons to shoot far and destroy their enemies and even if the distance minimized, I'm sure charging at a giant mech which has two miniguns, a plasma cannon, lasers and enough rockets to raze an island with a melee weapon is a really bad idea. To summarize, what kinda reason or situation would mechs have to use a melee weapon to engage another mech? They kinda look like this, hopefully with arms if they are using melee weapons. [![Mech](https://i.stack.imgur.com/LNLSO.jpg)](https://i.stack.imgur.com/LNLSO.jpg) [Answer] As far as we know IRL, mech fights will not be good way to wage a war, so this answer is meant more as an excuse for the writer, *not* the actual reasons. That said... # Limited ammo. Sword would weight about the same as two, three rockets? But with it, you could destroy more than three enemy mechs, if you are a good enough pilot. This does not make sense if you are close to your supply lines and your nation's resources are not limited. But guided missiles [can cost millions of USD](http://www.zdnet.com/article/how-much-do-smart-weapons-cost-the-military/). Literally. Thousands is pretty normal, if not cheap. Even unguided rockets are expensive. For the cost of few reloads, you could get one more mech. And of course you would need either transport mechs to bring rockets to your line, or maintain non-mech supply lines. These would be pretty hard to defend. Tanks, using non-rocket missiles, can carry more ammo, but they are low and can withstand a lot of recoil. Mechs, as high bipedals, cannot. So no large ammo storage for them, and no cheap ammo for them. Even if you can afford to make and deliver enough rockets, it won't work for special units you would drop behind an enemy's back. And you sure want some of these, for strategically critical missions. These missions may be suicidal, but that's the duty sometimes. # Urban war In dense urban areas, you don't see an opponent until he is one or two blocks away. For a mech, this is a few steps' distance, and at such a close distance a sword can be more efficient. The time needed to slash is shorter than the time needed to aim a gun. And with a gun, if you miss you are destroying infrastructure your side will need, a problem which is nonexistent for swords. [Answer] # Shield Technology Technology exists that can protect against small projectile weapons, but not against the much larger force and energy that comes with the swing of a melee weapon(as in Frank Herbert's Dune). For instance, a mech could be protected by auto-guided lasers that can vaporize small things like rockets and bullets before impact. Or, there's some type of surrounding magnetic braking system that slows bullets down to a speed where they can't hurt the mech. Only A melee weapon swung by another mech would have the energy needed to make it through the magnetic field. Hence, it would be necessary to outfit the mechs with large, sturdy melee weapons to destroy each other with. [Answer] Why would giant Mechs use melee weapons? ## Actually my answer is more for this question "Why using giant Mechs in the first place?" **Answer: Demoralisation** The party that uses the Mechs instead of conventional weapons has high advanced tech and wants to show it. Their Mechs are so advanced, that they can easily compete with Tanks of other parties and outperform them. Everyone knows how dangerous these things are. With the height of a small building they can be seen and more important, better identified than tanks. The tactic is to lower the morale of the enemy. Taking advantage of the fact that you are there and everyone knows it. # Now we come to the part why using melee weapons The Mechs should be able to get in close range to their target in a short amount of time. The longer that will take the more hits it needs to evade or absorb before doing anything. Actually I don't know how good tanks are in close combat, but I assume that they perform not as well as on distance. Everything that explodes would also harm the tank. Maybe the turret can't aim at the Mech because it is too close. The inability to attack the enemy with full efficiency could have an even more demoralizing effect. So the reason to use mechs is not because they are better in combat, but to strike fear to your enemies. You could make the mechs bigger than trees and houses. So advancing enemies will definitely see them when they stand up in the woods. In the end the mechs exists to prevent fighting in the first place. **No one wants to fight the mech**. [Answer] ## Serious radar jamming technology Take a note out of Gundam, one of the pioneers of the giant mecha genre. Wanting to write a plausible humongous mecha story but realizing that giant humanoid combat robots are pointless and impractical, the author created a world where a newly discovered particle made radar jamming easy, rendering long-range weapons useless against mobile enemies. Also I think it made problems for delicate equipment and computers. So human-piloted humanoid mecha fighting with melee weapons made sense. [Answer] # Fight The Enemy, Not Your Weapons The leading responses are all assuming an enemy similarly equipped, with similar tactics, when it is clear that asymmetric warfare is the most common sort of conflict. The only reason to use a mech with a melee weapon - or indeed a mech at all - is if that is the ideal weapon for the enemy you're facing. Such an enemy would be one that is most easily countered by a larger-than-life metal humanoid with melee weapons. These enemies would include ones who are easily intimidated by size, who are numerous enough that ammunition is a problem, who are embedded enough that supply lines are a problem, or who are constructed in such a way that projectile weapons are insufficient or inefficient (how many .50 caliber rounds does it take to stop a triceratops?) Note that while sticking artillery on a mecha seems 'a natural step', it's not necessarily the case that artillery is needed for the enemy at hand. If the mecha is primarily a sensor platform, for instance, which must be mobile over a variety of terrain but doesn't *usually* partake in combat. Or, the artillery in question is *so* long range (such as surface to space artillery) that using it in direct combat is impractical, then backup weapons are preferable which are, in turn, geared towards the sort of combat you're likely to face. Which brings us to... # Equip For The Job At Hand [![Backhoes demolishing buildings in combat zone](https://i.stack.imgur.com/v6xVK.jpg)](https://i.stack.imgur.com/v6xVK.jpg) About this image, ask yourself: why didn't they just use rockets? Contrary to a lot of answers here, urban warfare may be exactly why you want a mech with 'melee' weapons not because you protect the environment but because you are more dangerous to the environment. The ability to, on a rolling basis, demolish some or all of the environment you're in is a large tactical advantage. Such 'combat engineer mecha' can reduce enemy entrenchments and build your own while being protected against unexpected (or expected) attack. In this case the enemy is buildings, or open fields that need ditches, and the melee weapon (read: 'fancy shovel') is the best thing for the job. While it is a narrow set of circumstances where a large, bipedal mechanized humanoid is the best weapon of choice, should you also need a tool for your mecha for jobs such as destroying buildings or entrenching open ground, we can assume that pilots will quickly learn to use that tool to [squash endless waves of mimics](https://en.wikipedia.org/wiki/All_You_Need_Is_Kill) - you know, should they need to. Likewise, if the requirement is that the pilot is armored and unsupported for long periods over treacherous terrain, mecha may present a better option than, say, helicopters or other high-fuel devices or tanks with their reliance on some form of flatish ground. (Obviously there are *different* problems: the ability of the ground to support the mecha, etc. etc.) # Be Aware of Your Environment [![Cargo Loader From Aliens](https://i.stack.imgur.com/GlM2L.jpg)](https://i.stack.imgur.com/GlM2L.jpg) Is the cargo loader from Aliens the ideal mechanized combat instrument? No. But is it an effective one? Yes. Why? First, it equalizes the disadvantages the human has: provides armor, size and strength against an opponent that is larger, stronger and has blades. Secondly, and most importantly, it doesn't risk turning the environment against the humans. In this case, the environment is a space ship that, if breached, will mean defeat. Rockets and projectiles in this situation are exactly the wrong sort of weapon - for the same reason the marines should have avoided using firearms when underneath the main cooling tower for the nuclear reactor. In any situation where targets in the 'background' present a very high risk should they be inadvertently damaged, one must choose a weapon that reduces the chance of that happening. Space is one such environment: not only do bullets and rockets whizzing around often defeat the purpose of destroying your enemy, but due to Newton's Third Law (and indeed, the other two) shooting a bullet means you're forever accepting an equal and opposite trajectory (I'm eliding the actual physics here). Swinging an axe presents a different but more easily managed physics problem. # Be In Control of Your Equipment While it has been mentioned that projectiles can be stopped or confused in several other answers, this concept has not been abstracted to the general case: while that bullet/rocket/rock currently arcing towards your target might be 'yours', it is only that way so long as no one else messes with it. In a world comprised of EMPs, hacking, shields and other mishagus, once an object leaves your orbit of control you can't truly count on it being 'yours'. (And, notably, combat lasers and other 'beam' weapons might be prohibitively hard to make work, so 'instant hit' weaponry may not be on the table.) The nice thing about using a weapon physically attached your vehicle is that you are in direct control of it: if you lose that control you've already lost control of your vehicle, which is the far worse problem. The hardened electronics, active EW and black ice that is cost-effective for your vehicle but not for your rocketry can also protect a melee weapon. And, for that matter, in a super-high-tech environment, 'dumb' weapons generally need less protection (even if they are riskier). [Answer] Same reason knights in medieval battles carried daggers; **As a backup weapon, and for utility.** Battlefields are unpredictable, and no soldier will want to go into a situation where they might have to fight against someone who will have a total advantage. Imagine trying to direct ungainly arm/weapon pods of a mech while ducking and weaving at an enemy whose only a few feet away from you and doesn't have that limitation. Molot makes good points about ammo conservation and the cost of shooting things, but if you're going to build mechs anyways, I feel cost can't be TOO much in the forefront of your mind. An enemy mech that is melee equipped only has to swing his arm in your general direction when engaged at that range. If you get hit, even if it doesn't do much actual damage, your knocked about; your facing is probably changed, and your mech might very well end up on its butt and out of the fight. And, as with knights, someone quick and with a dagger was a real danger; they could get around you and shove it into one of the weak points of your armor quicker than you could turn to face them (*especially*) if you were bogged down in the terrain and they were not. Melee weapons grow in effectiveness if the ranged weapons (guns, lasers, missiles) require multiple hits to penetrate/kill. The longer it takes to down the other person, the more chance they have to close that distance and knock you off target. These type of encounters WILL happen in a limited visibility environment if both sides employ high mobility mechs; cities, fog banks, dust and rain storms. This is more endemic of warrior style combat then soldier style, where individuals and small groups engage without support, but is perfectly reasonable for commando style fights. Another major factor is the utility of melee weapons for mechs. Maybe your “sword” is in reality a giant shovel; its main job is to dig trenches and help construct a forward operating base. Even current soldiers digging tools (E-Tools) can in an emergency double as a melee weapon. Knights used their daggers off the battle fields for various tasks, including to eat with, and while probably not ever expecting to have to use them on the battlefield, took them anyways because “just in case”. [Answer] # Momentum If mechs have extremely strong armor then you need to deal extreme damage. You can't kill an elephant by pocking him one thousand times. You need a ram (call it a spear to sound more noble) with the momentum of a mech behind. This will have much more momentum or kinetic energy that any kind of bullet or rocket. To be a bit more scientific, there are mostly 2 reasons a ram can deliver more impact than a kinetic missile: ## delocalized burner A rocket can only deliver as much kinetic energy that it can afford to burn in its travel time. If this power gets too high, the engine burn or melt. Same problem with a cannon. The engine of a mech has the same constraint, but it has one engine for each joint and can afford a complex cooling system. Hence a mech can cool MUCH faster and can produce more energy over any given time. ## Aerodynamics Aerodynamics is on the melee weapon's side (maybe on the rocket's, but certainly not on the bullet's) To deal extreme damage, a missile needs to reach extreme speed... but then have to face extreme air resistance. A very large mass with a lesser speed does not have this problem. A 100kg Warhammer slashing at 200 m/s is possibly more realistic than a 500g bullet at 2800 m/s (10 000 km/h) and would have the same kinetic energy. And a 10t mech need only 20m/s to reach the same energy. You can increase this by setting your story on a high density atmosphere or even under water. [Answer] Can I recommend the Battletech universe as a reference? The entire system there revolves around mechs of one form or other. The major reason for using mechs in melee fights was that they weren't battlemechs. Many common mechs were construction, lumber or transport mechs, which wwere retrofitted for combat. So, lumber mechs had their chainsaws, construction mechs had mechanized hammers and so forth. The actual battlemechs had no melee weapons, whatsoever. However, I can think of a couple of tactical needs for bothering with melee weapons. As I pointed out in my earlier comment, any sort of interference with sensors, with some sort of terrain obstruction--be it fog or a steep mountain would mean you can't see the enemy till they're right on top of you. Since the sensors don't work, you can't risk sending tanks into the fog for fear they'll get stuck, unless somebody opens up a hatch in order to guide the vehicle--and then they'll be sitting ducks. That's when you send in mechs armed for melee combat. The mechs can cover any kind of uneven terrain better than a wheeled or tracked vehicle can, the transparent visor means the pilot can see where it's going without having to pop their head out. And most importantly, if they do see an enemy vehicle or mech, since they'll be right on top of them, they can respond immediately, without having to fall back in order to aim. [Answer] Because you want to rattle that squishy human INSIDE the mech without damaging the mech too much. It seems highly unlikely that a mech sized mace, axe, or hammer would pack more punch than a laser, PPC, gauss rifle, missile, or whatever ranged weapons it is using. But what a good thump with a chuck of steel is going to do is shake the crap out of the chassis, possibly stunning or outright killing the pilot inside without trashing the mech itself. Might knock loose some circuit boards, bust hydraulic seals, or the like which will also reduce the mechs operational efficiency without completely destroying it. Or, conversely, smashing exterior weapons or limbs can disarm the mech without destroying the (presumably) more valuable central control systems and perhaps even allowing the pilot to survive, to be ransomed later. Otherwise all you are doing is lobbing high explosives at each other, probably with all sorts of toxic byproducts (just read up on what happens to a tank hit by a depleted uranium sabot round, or that had DU containing chobham armor). The fundamentals of mech combat, at least in popular fiction like Battletech, assume a general withdrawal from the "total war" philosophy of killing your opponent by any means necessary and a return to a more, for lack of a better term, "gentlemanly sportsman-like" code of combat that allows for big fat high value targets to tromp around like the aristocracy of old, secure in the knowledge that if they fall in battle their personal safety is somewhat guaranteed. Plus factions wouldn't devote their entire economies into the war effort, so salvage and conserving fighting equipment would be paramount. Simply blasting your opponent into radioactive rubble might win you the battle, but lose you the war because now you have no way to salvage equipment to resupply yourself, make money to pay for your troops, and get hostages to exchange for your own/ransom off. Under these conditions, melee weapons make sense as a way to reduce lethality on the battlefield (at least for the mechwarriors, who are the only ones anyone cares about anyway). [Answer] ## Bad sensors Range weapons require you to be able to accurately detect the location of your opponent in real time and have weapons able to hit him. You could have situations were sensors are easy to jam or that there is snow or ash falling that blocks sight more than a few yards away. Frequent use of emp would kill sensors as well, so if you have to wait till a foe is a few dozen yards away you might as well use melee weapons. ## Unstable platform A biped walker is much more unstable when walking than a tracked or wheeled vehicle, this will make the weapons they fire less accurate at range, again encouraging close range. ## Durability Humans are odd if you punch a thumb-sized hole basically anywhere in them they can bleed out and die quickly without treatment. But a mech could survive dozens of holes in limbs and keep fighting, it could have valves to cut off the flow of oil or electricity to damaged sections and so survive and keep fighting despite the loss of 3 limbs. It would be hard to dismember a mech completely enough at a distance to take it out of the fight (basically punch small holes in it till it stops working). It might be faster to attack it in melee (cut large slashes in it) (especially if you have lightsabers) **Robots survive better than humans if small holes are punched into them so gunfire might not be the best way to destroy them.** [Answer] Why do humans that carry a machine gun still carry a knife, a sword like in japan, or an axe like the Indians and vikings did. I'd say as many already have ammunition. It can run out, it weights a ton. But the foremost reason I'd use a melee weapon in combat over high explosives, nuclear bombs, Plasma bombs and other explosive devices including mines is proximity and precision. Do you really want a nuclear bomb to go off near you even if you have centimeters thick composite armour when another mach stands near you? No you take your knife and find the weak spot in the armour. Personally I would like a spiked club that is electrified. he he [Answer] *Extreme* close quarters combat. I'd note a 'traditional' mace or axe would be a pretty terrible weapon on this situation. A Jackhammer the size of a small truck on the other hand, might be more useful in short range combat. Unlike a gun, you can power this off the same power supply as the mech itself, and it would be useful for combat engineer type work, demolishing and building fortifications and so on. After all, hitting someone in the head till they stop moving is a valid combat tactic. Likewise a high speed spinning blade might make more sense than a sword. A sword against armour might stop. A high speed blade would slice through. And similar weapons are in use in robot fighting tournaments, so you might have a 'in universe' explaination of pilots being familiar with such weapons - you'd have 'military' mechs with mainly energy and projectile weapons and 'gladiatorial' mechs that combine top notch pilots with limited armaments and physical weapons. [Answer] There's one thing that hasn't been mentioned, and I think it's a **very** salient point here. ***CULTURE*** In the West, we have this notion of the weapon as being a tool to be used and then thrown away and replaced when no longer useful (the culture of the *gun*) This gives the every-man a chance to stand up for his liberties and, in the case of the American Revolution, allowed a previously occupied colony to break free of its imperial masters and strike out on its own. In the East, however, they have much more of a focus of the weapon being an extension of the self. (Samurai Culture) This sort of weapon is generally always something that is either close combat, or in the rare-case of guns, then they're arm-cannons like Megaman and Samus Aran. These types of weapons take years to learn and many lifetimes to master fully. In the Sengoku Jidai (Warring states period) you had whole clans of Samurai, many who were descendants of Samurai themselves fighting it out for the title of Shogun. So when it comes to mechs, things like Gundam and NeonGenesis, which have their origins in the East have a much higher focus on melee weapons in their arsenal as that is the culture that that country is based off. ***EDIT - Thanks TechZen for the great point in your comment as added below:*** > > Actually there is little difference in the "Cult of the Sword" across world cultures. Medieval western warrior classes where every bit as mystical about swords as Samurai. Weapons become identity when an individuals status and general role in society depends solely on their ability to fight. The horrific reality of being trained from toddlerhood to kill, and belonging to social class were everyone else is a killer as well, creates a need to justify killing and that leads to the mystical veneration of killing tools as being something more spiritual, serving a great good. – TechZen 15 mins ago > > > [Answer] **Pure Intimidation** As Howard Taylor said in his [review of **Pacific Rim**](http://www.schlockmercenary.com/blog/pacific-rim-movie-review/): > > ... every technological advance necessary to create a walking mech will be obviated by better uses of that advance. As my friend Dave put it so brilliantly several years ago, (and I paraphrase) *"If your tech is so superior that you can get away with giant killer robots, the only reason to use them is for sheer intimidation. This means that what you should be building is giant killer robot clowns."* > > > What's more intimidating: a gun, or a massive *sword*? There's something just psychologically terrifying about a sharp blade in close quarters. Sure, we all know a gun can kill us... but a blade can *HURT* us - and we know that at the level of our brain that raises the hair on the back of our neck. Aim for the primal hind-brain and intimidate it: hit someone hard enough they either cannot or will not come after you... and fear is a good way of getting to the latter. ... although now I want to see a movie with giant sword-wielding killer robot clowns. [Answer] Consider this: The world is a changed place. Warfare is mechanised, and sending humans to the slaughter, to "die for their country" is no longer done - people don't stand for it any more. Battles take place between civilised organisations or even corporations, and civilian casualties or "collateral damage" is no longer considered acceptable. People no longer buy into the psychology and politics of hate, nationalism, or religious extremism. But battles still take place. The belligerents are powerful enough that governments are not able or willing to stop them, but not powerful enough that if they started killing people and destroying hospitals, orphanages and kitten sanctuaries, that they would get away with it. And battles still rage within urban areas. Now how do you approach it? You can't just start lobbing missiles and shells around because you might miss and turn the city into a wasteland. Instead, you have large lumbering mechs, armed with large melee weapons made of highly advanced pneumatics and technologium - a metal composite that is so hard and sharp that it can cut through enemy armour, buildings and machinery without damage to itself. And with no chance of stray missiles or big explosions, it minimises the risk of killing innocent bystanders. Perhaps the weapon can also be electrified, doing further damage to enemy machinery (if cutting by itself isn't enough) **Edit** Maybe there's some outdated law that forbids projection of a potentially lethal missile - updating the law to stop melee weapons has become tied up in the bureaucracy. [Answer] Many many good reasons in many answers here, but here's another one: your projectile weaponry is too dangerous to yourself to use at close range. Why would depend on the weapons. Missiles are not something you want exploding into your face - if they can damage an enemy mech they can presumably damage yours as well. If you're using energy weapons, maybe it's not the weapon itself but the splashback as it burns its way into the enemy's armour, sending a jet of incredibly hot plasma right back at you. So when you get close enough for this to be a risk, you switch to something that doesn't set you on fire. [Answer] The author of Dune, Frank Herbert was brilliant in that, although he did not use mechs, in his novel the weapons cannot almost never be used, they have laser weapons but they don't use them because if a laser weapon hits something protected by a shield that result in an atomic explosion. In a world where weapons are so advanced and damaging that they can cause devastating side effects it is preferable to not use weapons: **Conquering a city:** if you are fighting for a city maybe you want to avoid civilian kills and damaging useful buildings and facilities. Bullets cannot pierce armored stuff they just get deflected and hit random targets, you could use U-238 bullets but those are radioactive and not suitable for urban environments, RPGs are not an option again because they can do big damage to small sections (yes they can pierce armors, even reactive armors, but if the target is big and moving they do less damage). **Killing specific targets:** If you want to kill only a specific target maybe you can prefer melee weapons because you save money on ammunition. **You want actually to kill pilots:** If mechs are heavily armored it is likely that just hitting a obstacle could kill the pilot but leave the mech undamaged (you now head bones are weak, and mechs armor is very hard). Using melee weapons could result in killing pilots and leave mechs undamaged so you ca reuse them (if you are able to win the battle). **You actually own the "ignitor":** there was a novel where a scientist find the weapon that could put a end to all wars, it was a weapon able to ignite anything flammable at any distance, so basically that weapon was able to destroy all ammunition and explosives and fuels, this open for worlds with chemical weapons, battery powered mechs, melee weapons and biological warfare. So that weapon in reality just not ended all wars, but removed explosives. **If you have not explosives, melee weapons are most efficient:** yes you can use a laser, but lasers require great power and have the side effect of make blind everyone in nearby surrounds not wearing protective sunglasses (and anyway cutting through a whole mech armor is not an option, to cut metal with laser you need to move it slowly, no target would stay still). Probably you want weapons to put enemy mech unable to move, and then later use eventually a laser to cut it while he is hold still on ground. [Answer] # **Energy Shields** You know those things that stop particles from going through your ships when they travel with their faster-than light speed? Well slap one on the mech - the faster the enemy projectile the more resistance the shield exerts. King of like falling in water with high speed vs slowly dipping in. Sure you can chug a grenade under the shield and blow the mech's legs, but if the shield is very tightly wrapped around the body instead of an umbrella style that tactic doesn't work anymore. If you want to still keep ranged weapons viable then you can just make the shield generators "overheat" if they sustain too much fire. Tanks (and maybe soldiers) will be equipped with the same shielding and remain relevant (although at a disadvantage). # **The return of mele weapons** **So now using a "slowly" swinging sword isn't that unfeasible anymore...** Your mechs can run around and chop tanks, infantry and other mechs as much as they like without worrying about being turned into cheddar cheese. Make them carry a metal shield (or a fancy energy one with same shape) and sword for extra protection and epicenes while fighting. Though if melee is truly the best options then you'd probably see most mechs use Shield & Spear instead ... just don't step on a landmine [Answer] "I mean, shoot the legs and they can't move much anymore." There's your answer. Mechs need to be armoured to withstand enemy action and remain in the fight. But they can't be too heavily armoured because then they won't be mobile enough, which defeats much of the purpose of a mech. Given that the greatest threat to a mech would be ranged projectile weapons, often aimed at the legs, this means that the logical armour selection would be reactive and/or composite, similar to what is used on armoured fighting vehicles today. The end result is that in close-quarters combat against another mech, their projectile weapons are likely to be ineffective against one another (assuming they can even track at that range). Now I don't know much about the effectiveness of reactive/composite armour against mech-sized melee weapons, and unsurprisingly there appears to be little research on this topic. What I do know is that a melee weapon of that size is going to have a **lot** of mass, which means a lot of kinetic energy; quite possibly more than a projectile-defeating layer of armour can absorb. (Not to mention the difference between how that energy is being applied; compare a blade's edge strike against a sabot round impact.) Thus a melee weapon has two purposes for a mech. Firstly it's likely to be the only viable way for mechs to engage each other at close quarters. Secondly it makes use of one of the innate strengths of a mech - massive amounts of power, backed by high mass (both of the weapon and the mech itself). [Answer] ## Pathos If creator of the universe practices Rule of Cool, then inhabitants of the universe would eventually notice this and deliberately do cooler things. Cool things would work despite boring physics and common sense. Well, from their perspective, Rule of Cool would be a part of physics itself. Take a look at [spiral power](http://gurrenlagann.wikia.com/wiki/Spiral_Power) as an example. [Answer] ### Projectile weapons may become prohibited Similar to chemical weapons, projectiles could be prohibited in war. They often go off target, result in significant non-target casualties, and are a very blunt instrument for war. It's possible that such weapons may simply be banned in the future, leaving melee combat as the only option. [Answer] There's some great answers in this thread already, but I'll add a couple reason in-universe reasons from various mecha media. ## Mobile Suit Gundam In the original UC Gundam universe, the development of compact fusion reactors led to the discovery of the Minovsky particle. This particle is high-energy and had a side-effect of forming a regular grid-like lattice when released into the air or space. This lattice has many in-universe uses, but the most important aspect of it was that it acted as a sort of particle-based Faraday cage, blocking electromagnetic radiation, including radio waves. With Minovsky fusion reactors being used in most starship, and soon miniaturized by the Federation of Zeon and used in their new Mobile Suits, Minovsky interference caused radio-guided and other non-Line of Site weapons to become effectively useless, moving combat back into close quarters. Mobile Suit combat became the standard after the One Week Battle, and most Zeon mobile suits were armed with standard solid ammunition weapons like machine guns and rocket launchers, so many of the were equipped with Heat Axes and other physical close combat weapons as well. Most of the other Gundam franchise shows don't really follow this, however, so it only really makes sense in the UC universe. In Gundam Iron Blood Orphans, all Gundams' armors are made of beam deflecting materials (to encounter the Mobile Armor they were designed to fight against) and a Mobile Suits' frame is almost indestructible, so the only way to take down a Mobile Suit is to use blunt force to deform the frame (skeleton, if you will) enough to squeeze the pilot to death. ## BattleTech/Mechwarrior When the BattleMech was first developed during the days of the Terran Hegemony and up until the last days of the Star League, Mechs were a combination of mobile tank and artillery platform. However, after the collapse of the Star League and the beginning of the Succession Wars plunging the galaxy into total war, the method and means to design and manufacture advanced weapons, and indeed even some Mechs, was soon lost or no longer understood. Warfare devolved into close combat affairs, with Mechs becoming heirloom objects passed down through the generations. Most combat also took place in urban areas, where close-combat weapons like the Hatchetman Mech's eponymous hatchet has the advantage, while many Mechs also make use of fists or feet to deliver blows of tons of steel. For almost 300 years, combat in the Inner Sphere is waged like this, until the return of the Clans. As a contrast to the Inner Sphere, the Clans are descendants of a commander named Alexander Kerensky who fled the Inner Sphere before the First Succession War and established a new culture of peoples. With advanced weaponry and brilliant military tactics, they took the Inner Sphere by surprise and cut a deep swath toward their main objective: Terra. However, the Clans are also an honor-bound military culture, and they look down on things like close-combat as dishonorable. This, along with some clever maneuvering by another faction in the Inner Sphere, ComStar, allowed the Inner Sphere to defeat the clans at Tukayyid and halted the Clan invasion. [Answer] Mecha can probably be defined to range from anything the size of powered exoskeletons (which are currently being researched/developed by DARPA) up to the Godzilla-sized monstrosities of the Gundam series and other works of fiction. In a space-station or similarly enclosed environment the need for well-armored peace-keeping soldiers may necessitate some use of these smaller-sized mecha, while the close-quarters environment and high-cost and high-risk of collateral damage may pose strong disincentives to the use of projectile weapons. (All police would carry batons/tasers/swords instead of guns if a hull-breach is an immediate and apparent danger, right?) If these peace-keeper models are mass-produced to far greater extent than their full-scale total war counterparts, then it seems quite feasible that a number of different locales may see a large number of these smaller bots used in conflict even if the big-dollar top-tier bots are more effective in combat. Furthermore, if the littler bots are in widespread use they might already be on-the-scene as conflicts develop, meaning they might transition from peace-keeping to warlike roles to fill the void as heavy mecha are still in transit. [Answer] Have you ever played with 'gak'? It's a non-newtonian fluid made from corn starch and water. If you hit it or apply a lot of pressure, it hardens, but if you press it slowly, your hand will slip in. I've always thought that in these melee-ed mech futures, it must be that shield technology works a similar way. Something going too fast? Apply resistance. Something moving slow? Probably just the pilot getting in or out, let through. A melee weapon isn't fast-moving enough to trigger the shield resistance, so it it is suitable for taking out enemy shielded vehicles and mechs. [Answer] # The environment might require it It has been suggested that the lack of line of sight in an urban environment, especially coupled with dense fighting where ammunition might be limited could advantage a fast, repeatable weapons system. This also seems to allow things like laser cannons. These sorts of atmospheres would also help explain the odd absence of air superiority already mentioned. ### Dense atmosphere But what if the 'air' of the world the fight was taking place on was especially opaque? A near equivalent on earth would be fighting in a very strong sandstorm, or underwater. This sort of environment could plausibly prevent optical weapons and small arms fire from functioning, and an urban or choppy terrain would prevent/discourage rocket based weaponry. ### Reactive atmosphere A highly flammable or chemically reactive atmosphere, perhaps one very high in gaseous hydrogen and oxygen, would cause large fires/explosions when a rocket or laser was fired. The mechs could well be shielded or armored sufficiently to prevent machine gun fire from being strong enough to damage them meaningfully for the weight it imposes on the holder. # There might not be room on a mech to defend against everything It's not hard for me to imagine that the shielding/defense/armor strategies that defend against lasers/swords/rockets might all be different. If there wasn't a unified technology to defend against the varied attacks you would have to make speed/size and energy tradeoffs in defending a mech. These things are going to be awfully heavy, and on the sort of rough terrain already described as preventing tanks, maybe you just can't have all the different technologies on the mech and still have it able to transverse the terrain. It could also provide to much of a power or resource drain on either the mech or the society building them. This sort of scenario is, to some extent, why we don't only use tanks as it is. There are just places you can't go if you weigh 100 or 200 tons. # Those weapons don't exist As in some of S.M. Stirling's books, you might imagine a world where the technology for lasers/rockets either can't or doesn't exist. If gunpowder and rocket fuel were much more complicated to invent, it doesn't necessarily preclude the invention of computers, robotics and nuclear power. So you could have this sort of weaponry evolve from a society that never develops any sort of firearm. A similar scenario could be accomplished by envisioning the development by an alien species with very limited sight. They might never develop firearms because they can't use them, but they are able to develop mechs that interface well with their other senses, and are armed as the society has always been, with swords and the like. [Answer] # Stealth/Ammo For me the first step to figuring out why I'd prefer melee over ranged weaponry was thinking about what other situation I would prefer melee in. My first thought was zombies. In every book about zombies it is recommended that you bring melee weapons only. Why? Because they're quite and wont attract more zombies and because you don't have to worry about running out of ammo. This same logic can be applied in military combat. In stealth mission you may want to get in, kill a target, and get out without anyone knowing. Sure a sniper could do this but I'm sure you can think of some reason that long range silenced weapons are out of the question (i.e. shielded walls, underground bunker, etc.) So instead of going in guns a'blazin you can sneak in (the best you can with a mech) and do you job without alerting the whole infantry down the street. During this stealth mission you may find yourself way behind enemy lines. With no time for a supply drop or perhaps your command doesn't even formally recognize that you're there, you're on your own. Why risk running out of ammo and becoming sitting ducks, your sword never runs out of killing power. [Answer] Hmm... assuming a world where humanoid mecha are a viable combat option, it would depend on the weapon, really. Normal melee weapons, as already said, can be used until they break, instead of needing to be reloaded every so often; even a mecha-sized bladed weapon will be heavy enough to make a good club if the blade dulls; this prevents the mecha from becoming a giant, helpless bullseye after it runs out of ammo. Assuming the mecha already has humanoid arms so it can cover a wider area with its ranged weapons, they're also more cost-effective than ranged weapons. Melee energy weapons, on the other hand, would mainly differ in that they can be more efficient than ranged energy weapons. A lightsabre, for example, bleeds very little energy while active, except when in contact with another object. A ranged weapon, on the other hand, would consume energy every time it's fired, regardless of whether the shot hits anything or not. This could potentially allow it to remain operational longer, or get in more attacks before having to refuel, assuming it isn't offset by the energy consumed while closing in. --- Alterntively, it could be used to help counter mecha with ranged weapons. All things considered, most mecha-sized ranged weapons are going to be unwieldy at point-blank range, meaning that if you can get close enough for melee, you can destroy or heavily damage the mecha with little resistance. This could lead to the production of melee-oriented mecha for veteran pilots, which combine melee weapons and high maneuverability & speed to serve as "mage killers", closing in on ranged units while evading their attacks. This, in turn, would lead to ranged mecha being given backup melee weapons so they can defend themselves up close, and soon enough all mecha will be armed for both close- and long-range combat. This is especially true if the mecha are designed for aerospace combat, and thus will be much more maneuverable than purely land-based units. There's a very real possibility that they'll be able to approach enemy units very quickly, which would mean that giving them melee weapons would be a logical choice. [Answer] ## 1. More damage Momentum: m1\*v1 = m2\*v2 Whatever damage a missile, cannon, or armor piercing round does, it can be dealt significantly higher in melee. A 2-ton sword will deal far more damage than a 20kg AP missile. ## 2. Recoil Past a certain point, firing heavy cannons will cause so much recoil that it will topple a mech. Missiles will require a lot of fuel to carry a heavy payload. You'll still get recoil through melee, but a good pilot can control it in such a way to prevent from falling over. ## 3. Ripping off limbs Missiles and rockets can have great armor piercing and damaging internal components. However, they are ineffective for simply ripping off another mech's arms. A heavily armored head could be able to withstand high explosives and a direct plasma blast. But put two tons of force behind a punch and it can probably rip the head off, even if the mech's arm is broken in the process. [Answer] **Why Mecha/Mechs at all?** I believe the plausibility lies with instinct. Is it easier to lift and stack cargo crates with a crane or lift and stack bricks by hand? The brick stacking does not require much in the way of training; you already know how to operate your hand and arm. Assuming the tech level is sufficient where the system is integrated with the user, and the system operated as a sort of augmented reality where the nerve impulses controlled the machine and provided sense feedback ("what am I grabbing, what am I stepping on" kind of stuff). We will probably see them first in industrial and exploratory roles in inhospitable terrain. There are some pretty cool logging technologies being used right now like the Hexapod, it can walk where trucks and tracks can't go to harvest trees. Logging operations in mecha would probably be about like clearing brush for a human. This only works where the mecha is an extension of the user and integrated into their nervous system. Just operating a mecha-shaped machine would likely make it more complicated. [Answer] Both sides possess a weapon that destabilizes explosives. It's an energy projector that can't be shielded against. (I forget the story but some major Sci-Fi author has a book (novella?) based around such a device, although used for peaceful purposes.) Get too close to such a generator and any warheads detonate, any rockets take off, any bullets fire. In such a battlefield you're not going to carry anything of the sort, thus you are limited to melee weapons, lasers, railguns and coilguns. Lasers have severe power density problems. The sort of laser you could mount on a mech would be hard pressed to do much to enemy armor but would cause you severe heat problems. Both railguns and coilguns won't be able to do much given the short barrel length possible on a mech and if you manage to put enough punch into them you run into the recoil problem mentioned in another post. ]
[Question] [ Creating an entire world is a daunting prospect, though something I've thought about often. Ideas about different regions, religions, people, history and relationships all blending into a cohesive world come half-formed to me. But how can I go about turning these into a believable world with a foundation for adventure? What steps have those of you who have built entire worlds taken in the past to break this task down into manageable chunks? [Answer] # Determine What is Important for You You need to figure out what parts of a world are needed for whatever you're making this world for. Do you only care about the social interactions? What about the physical properties of the world? How consistent does the world need to be? You also need to consider your audience; is the world for a readership? For role-playing games? What's important to them? You must consider these needs throughout your design process. # Throw the Ideas Together for a Framework! Start assembling your ideas together in a rough framework. It doesn't matter that some things may appear contradictory. (Apparent Paradoxes happen in the real world sometimes, too.) You're just building a framework to build your world upon. Your framework could be a map, timeline, a plot-line, an encyclopedia, or a relationship map between people or countries. The important thing it that it shows your ideas for this world, no matter how half-baked! # Examine Your Framework Does it meet your standards of consistency? Does it have what you and your audience need? If yes, then continue on. If no, figure out what needs changing. # Flesh Out Framework From the framework, figure out the properties of individual things in that framework. What are the social aspects of this country? What is this person's personality? How do the interactions on your framework occur? Once an individual item on your framework has sufficient detail to meet the needs of you and your audience, move on to the next item. **A Note About Assumptions** You will make assumptions when making your framework; most worlds are described by how they differ from our real world. If something is not explicitly stated as different, your framework should run under the assumption that things take real-world behaviors and values. If this isn't the case, your audience needs to know! [Answer] World-building is (in theory) an infinite task. By typing that question you were building this world, and by writing this answer I'm doing that too. I think it's important to first realize that we are always building as we go, no matter how much we want to do before we start "writing stories". That being said, I like to think of the process of world-building being broken up into two steps; world-building and world-populating. ## **World Building** Define some yes/no **world rules** across a range of areas (see below) that are accepted truths to you, the builder (and your team of builders). These are things you know to be true in the world. You need to work with constants at all times when building. This is not the time for hypothetical answers that your characters might offer to the same questions, because you shouldn't *have* any characters yet. The key point to this foundational step is that, it doesn't matter what the answers are; what matters is that *you* know what the answers are. **Leave Philosophy At The Door**. Areas you might want to consider: **Cosmology**: * Star type (main sequence or a later stage star?) * Planetary position (in the circumstellar habitable zone?) * Planetary movement (moving towards the star or away from it?) **Planetary**: * Planet type (Earth analog, gas giant, iron core?) * Planet diameter * Atmosphere (Is there one?) **Spiritual**: * Deity Existence (Do divine beings exist?) * Deity Scope (Universal?, Planetary?, City-sized?, Smaller?, Or do they having a different sorting order altogether?) * Evolutionary system (Adam & Eve, Darwin?, Lamarckian?, Something Else?) It's difficult to pin down an exact set of areas to divide possible questions up into, because the way you categorize things might be slightly different from person to person. For example: "Is climate part of physical geography or separate?" "Well that's semantics, isn't it?" Either way, you'll most likely look at both climate and physical geography during your world-building. ## **World Populating** Populating your world is giving life to it. I like to think of it in a very *binary* style of objects and events. Objects are things that appear in the world, events are things that give my objects a reference to time. My characters, species, regions, settlements, food stuffs, political states, deities, rivers etc. are all objects. Their births, deaths, battles, coronations, adventures, floods, foundations, destructions are all events. IMHO, world populating comes **after** world building. Populating before building could lead to inconsistencies down the line. You might want that, but if you don't, it's a real headache. **Timeline**: Consider this one early on. Time is constant, the numbers and dates we mention are just overlays or masks to help us understand it more easily. A timeline will help you get a sense of perspective for where your story/ies will be taking place in the history of the world. Start with the largest chunks and then subdivide to give greater detail. In the real world our largest chunks are special (species) related. Dinosaurs(saurians), followed by mammals. You might want to do something similar. We then tend to divide this on sub-levels based on technological/evolutionary/physical developments; stone, copper, bronze, iron, steel, renaissance, enlightenment, industrial, digital etc. It makes no difference how you do this, because at the end of the day you're only ever counting seconds :). **General To Detailed**: Populate your world like you would paint a picture. Sketch it out first, then add greater and greater levels of detail in a logically sound order. If you want to add a character into your world and say they are born in region A at this time, it would make sense to already know what the majority species living in that region at that time is. Is your character therefore fitting the mould or from a minority? Start at the beginning of your timeline, and sketch out where your species are going to be. Work through your timeline and move them about a bit. With the movement of your species, you're ready to look at cultures & languages. Different cultures and languages (in theory) come about due to the break-up and dispersal of groups of a species to different locations, who then lose contact with each other long enough to affect their customs & speech. If you follow this theory, you can't comfortably know where and when you will have different cultures & languages until you know how your species spread, separate and come to settle. Warning: you may not want to worry about this level of thought & detail. But for those "purists" out there, the spread of your species across your world will determine how you design where your cultures & languages originate from and they themselves spread to. There are others who will say jump right in and have a go, and that might work for you. I think it all comes down to this question: Is your world for one story or for many? If you're only going to tell one story from one point in time, your world is 2D, and you can jump right in and start from wherever you like. If you are planning on having multiple stories, hundreds or even thousands of years apart, you've got a 3D (or perhaps MD: multi-dimensional) world. The stories that happen chronologically later need to agree with those that happen chronologically earlier, but there is no guarantee the order you write them in is the order they *happen* in your world. If you're planning a 3D/MD world, I recommend following the example above. [Answer] This is an exciting question. I'm sure everyone has their own methods, so it is going to be fun to explain mine. I'l call my method "Start Local, Think Global." First, I always find it most helpful to start at a single point, a home base where your protagonist(s) start from. What is their environment like, and how does it affect their lives and motivations. Build a village/town/city/state around them. Concentrate on a single locality with descriptions and it's inner workings. Here is where the details of many events will take place, so this is a very important place to begin. Even if you burn the place down, it sets the tone for how the rest of the world will look. Next, how does this place compare to the rest of the world? Is it average? Is it idyllic? Is it poor in comparison? From here, we can start putting together what at least part of the world is like. I try not to assume that the world is homogeneous, so far away places will most likely fit a different mold. From there, world building becomes a balancing act of adding new nearby places, comparing them to current places and then figuring how all the pieces go together. One of the most difficult parts is figuring out how different areas relate to each other. What is their history going far back? At some point in time, even the closest allies were probably at war with each other. Also important, is revisting places to update them as new global ideas get added. There was a big blizzard in Antelope? Well then Bison, Caribou and Duck probably got hit too... As the world gets larger, I then start throwing down larger countries/kingdoms and giving those large areas a story, mostly as starting points for diving into those regions. I never fill in a new area unless I'm sure I'm going to need it. There's no reason to describe the capital of the Kingdom of Zugzug unless you're going there. Sometimes over planning can paint you into a corner. I'm sure there is a lot of difference of opinion on that, I know many people like to construct everything ahead of time. I prefer flexibility going forward. I like to create what I NEED, and a few extra things that I might potentially need. There are a lot of places to go in a well constructed world. Most importantly, the world is always changing. There's peace, there's war, there's disasters etc... How is the world going to look a month from now? How do the current events look to affect the future? Wow this is a fun topic... [Answer] There are a lot of different approaches to doing this. My personal approach is to drill down into the primary area of interest and then build out from that as you need it. It's impossible to fully map and design an entire world to high detail, so you need to concentrate your effort and that detail to locations where it is needed. So I start by sketching out the overview of the area to whatever your largest scale is. For example for a recent game I ran I started with the concept of two continents, one to the north, one to the south. The players are colonists from the northern continent exploring the southern one. Since this was for a game I'll be saying players but if this was a novel you could easily replace "player" with "protagonist". Immediately that let me focus in on the northern end of the continent so I started sketching out the rough terrain. Mountains, rivers, etc. Trying to build a believable geology and geography. Once you have that you can start seeing where humans would build. Where they would start building their first settlements. Think about the history of the land and how it might have changed over time, has a town been built recently or has it got a long past? For example a town that's changed hands many times through war might have massive defensive walls and buildings in a variety of styles while a safe village in the center of a protected country might have no defenses at all. Now I know what settlement the players are starting at so I drill down into that one again. Design the layout, work out who the leaders are, what the beliefs, laws, and society is like. Try and get the flavour of what the settlement feels, sounds, looks and smells like. Decide what facilities it will need to provide, for example a market, specialist shops, etc. Just as importantly decide what things it does not provide. And then from there you can finally map out the settlement, placing the important buildings, working out the road layouts, the walls, etc. Now you have the starting point, so you need to seed it with hooks for adventure. What problems might this settlement face that it needs the players to help them with. Perhaps the water supply is contaminated, maybe there are dangerous beasts or unexplored ruins nearby. At this point you are actually ready to start running the world, as the players decide where they are going you can continue fleshing out the skeleton adding meat wherever you need it. Gradually the explored area grows, the mapped area gets more detailed, and the world expands organically but because you started with the skeleton it does so in a cohesive and self-consistent way. Take a look at [a world that was created this way](http://www.giantitp.com/forums/showthread.php?334254-Perilous-Reclamation-IC). Unfortunately you're seeing the details after the campaign has run for 8 months rather than the original which had a far smaller explored area and only one settlement but you can still see how it came together. My own maps cover a much larger area than has so far been explored (and those maps are not yet published or visible), but only in large enough scale to keep things consistent. As players explore each area I drill down and flesh it out more as required. [Answer] I know my answer doesn't compare to the others, but one tip I have is this: Imagine your world, half-formed or not as it is, and do narrative "test drives" on it, and gauge its reactions. A world is nothing if not a set of reactions. Even if it's in a medieval, realistic setting, think what would happen if a nuke dropped in the middle of it, how would people react (social psychology), would people attribute it to a deity (religions), would people be able to tell that it's biologically damaging them afterwards or would they call it a curse (science and superstition). Make dummy characters have some things to do, generic or not, to be able to see the world through their eyes. It's easier to see the world that way than from up above. The sergeant of a king finds a source of magic. Who does he tell? How do the people react. A war breaks out. How is it fought out? Who would win and why? Do all sorts of things to your world and test its reactions. You can't have X react to Y without finding out something about X. Best of luck! [Answer] I like and recommend following the advice above, but I wanted to add a bit more information to this. **Resources for you** People most often perform World building to support some other activity - most often either writing a story or building a game. In either case, someone has already gone through the effort of collecting scads of science and reference materials to aid you in your efforts. Try these resources: * [Atomic Rockets: World Building](http://www.projectrho.com/public_html/rocket/worldbuilding.php) * [World Building Institute](http://worldbuilding.institute/) Topics to cover in World Building: From World Building Institute: ![Topics to cover in World Building: From World Building Institute](https://i.stack.imgur.com/xXrZ6.png) **Bottom-up design:** > > World building can use top-down or bottom-up design, or even a > combination of the two. > > > The major elements of world building are: > > > 1 Physics > > 2 Cosmology > > 3 Geography > > 4 Natives, Flora, and Fauna > > 5 Culture > > > [Most often] The elements at the bottom are more important [for a > story than those at the top], [if they start at the bottom] the author > can decide how high up they want to go on the list. > > > However, stories written this way tend to have more problems with internal consistency than those written with the top down approach. **Top-down approach:** If you plan to generate lots of material about your world/universe and wish for it to all remain consistent, it's usually better to use the Top Down approach. **Other thoughts** If none of the approaches suggested in the reference materials work for you, realize that many authors often just start by doing whatever they love first and then fill in the blanks around what they created. For instance, [JRR Tolkien first developed the languages for his novels because he loved languages](https://en.wikipedia.org/wiki/Languages_constructed_by_J._R._R._Tolkien). Later he developed the mythology to go with those languages and filled in the blanks. [Answer] I break it down into the following in approximate increasing order of complexity. These may be taken in any order as ideas occur, but the earlier topics are the most fundamental and changes will have more significant impacts on all the rest of the world. These are also interdependent, and capable of unlimited subdivision. 1. **Nature** This includes physical properties, chemical composition, the geology and geography of the world and its size, landmasses, landforms, oceans, and atmosphere. It also includes the biology, plant and animal life, and astronomical bodies (sun, moons if any, other planets, and constellations) 2. **Personal studies** This includes the biology and psychology of the dominant inhabitants, whether they are human, humanoid, or other. It also includes key historical figures. 3. **Social foundations** This includes such things as social group behavior, the population and population density, subsistence patterns, geographic distribution, effects of the environment (such as natural disasters or plagues) and important groups of people. 4. **Culture** This includes sub-areas: 4a. Technology: (food, clothing,building, transportation, communication, tools, and other artifacts. 4b. Concepts: Language, mathematics, literature and stories, visual arts, calendar, applied science, and philosophy and ideology. 4c. Behavior: Customs, occupations, performing arts, recreation, holidays and so forth. 5. **Social institutions** This includes family structure, educational systems, economics and trade, political systems, and religion. 6. **Societies** Specific communities: settlements, tribes, and nations. 7. **History** Historical development of the entire world, or specific elements of society [Answer] I don't like the concept of breaking it into chunks. Creating - no, *imagining* - has no limits, rules or methodology. And following rules to go about doing so, is only going to have you fit the same mold as everyone else. If you are interested in having what people so easily call a Tolkien or Dungeons & Dragons or Harry Potter (etc...) clone, then go ahead. Chances are you will still have your own unique elements and it will still be "your" creation. But think of what you could end up with WITHOUT following that beaten (to death) path. I've been making up stories and games and works of all sort (music?) ever since I was a kid, and I find the most compelling ideas I've had are the ones that were just sorta thrown together, the ones that just *happened*. The ones I find least appealing, are the ones I tried to hatch by emulating something else. One thing I like to do, is start with something stupid simple. For worldbuilding? Tell a story. It doesn't matter where it is going, but you will be creating your world through that story. (I'm not talking creation myths here). You tell the story of Hilbert that is going home to sleep. Without realizing you will be figuring out what kind of settlement he's living in, who are the people around him, what the environment is like, what clothes, language, year this is set in. Etc.. etc.. etc.. Normally I have something world-changing happen in the aftermath of Hilbert's story. And THAT is where my worldbuilding comes from. So I have some backstory to my world that will hold everything together (more or less). The longer and more complex Hilbert's story is, the bigger and more complex my world will be, and the slate for whatever story or game or drawing I want to make on that slate will be that much more compelling to me (and hopefully others). Hilbert's story doesn't HAVE to make perfect sense because it will never be told, it's just a base for whatever ELSE you're going to do. But anyway, I might just be rambling. I generally prefer stories based in non-nonsensical worlds anyway. [Answer] I want to recommend a book that is helping me a lot in this process (and also giving me a lot of inspiration). The name is [World Builder's Guidebook](http://rads.stackoverflow.com/amzn/click/0786904348) by Richard Baker. Although it was originally made for Advanced Dungeons & Dragons the contents are dedicated for Story Writers making a fantasy world (you don't need to known anything about D&D or RPGs to read it). Here is a image showing the book index![enter image description here](https://i.stack.imgur.com/8gB7C.jpg) The book is kind old, but you can find it in pdf format on the internet. But I didn't tell you this! ;) [Answer] There are a lot of nice resources and ideas for world building here but, in my opinion, and as spacemonkey has alluded to, as an author the most important starting point is to **understand what type of story you want to tell and begin by creating a world to help you tell that story**. The rest are just details to make it feel more real. For example, if you're doing a future Earth story, you make the changes you want with present Earth to get you to that future place. If you're doing an off-Earth story then you need to ask yourself why you're setting the story off Earth. i.e. What you are gaining by putting it off Earth and what you hope to accomplish with the story. When you know these things, the fundamental physical and social structure of the world almost automatically falls into place. Of course, you can challenge tropes at this point to give it something non-standard, like setting a fantasy quest in an urban centre, but that's your choice. After this it becomes ever greater fine tuning with the addition of things you need such as power structure and economy if you have any kind of population centres, trade or marketplaces; animals and environments if your story has any wilderness; etc. [Answer] I'm going to make some assumptions here. First I assume you want a world that is inhabitable by humans. Second, I'm going to assume you want to build a plausible world, otherwise you would just make it up. And third, I'm going to assume you want it at least somewhat scientific. As others have mentioned, you can spend way more than a lifetime doing this, but what a cool lifetime! I always start from the big picture first. What is the solar system like? How many suns? How many moons do you want around the planet? How many other planets and how close? What are the orbital characteristics of the planet? The reason you want these is if your characters look up in the sky, you want to be able to answer the question, how many moons does he see. Or how many suns. You will want to know how long the day is. If the planet is tidally locked to a sun, there might not be a night on one side of the planet. If there are two moons, what kind of havoc is created with the tides? You have to have tides because you have to have water. Also, how heavy is the planet. A heavy planet will have smaller mountains and stronger people, that move slower and vice versa. All of these macro planetary decisions should be made so you know how long a year lasts and if there is planetary tilt if you have growing seasons. Is the orbit eccentric? Maybe summer is too intense to survive year round. All of these things affect the daily lives of the characters. That is chunk one when I create a world. Chunk two is planetside. What is the world like? Lots of plants? Desert? Cold? Hot? Watery? Poisonous? Is the atmosphere heavy or thin? Oxygen Nitrogen mix? So on. Personally, I'm not a big fan of planets that are ALL one thing, like water or desert. Here on Earth, we have it all. For that matter, I don't like planets like in Star Trek where they have only one society that speaks for the whole planet. On Earth we have many countries. I think building the solar system is the most fun and straightforward because you can calculate a lot of the features to get some realism. The planetside stuff is harder because it depends a lot on the mechanisms that drive a planet, like chemical make-up and complicated wind and ocean currents. After that I start populating the planet. I think that societies often have traits that are dictated by the planet. People that live in coastal areas are often very good at maritime activities and derive a lot of their nutrition and customs from the sea. Desert environments require a lot of economy. Economy of water, of exposure to the sun, of dietary consumption. Too much running around out in that sun can cause heat stroke. More clothing might be needed. Cold environments are low energy. Not a lot grows there. Predators may be more tenacious since they may not find other food. On Earth most of the stuff, flora and fauna, is concentrated around the equator. The population will include lots of animals too, I would imagine. Figuring this out is pretty daunting, so chunk three might be taking a crash course in evolution. I think societies and relationships are not necessarily part of the world building because that's what you are writing about in the world you have just created. Clearly they ARE part of world building, but I'm assuming that you kind of already have a story that you now want to place in your newly constructed world. Perhaps some of the ideas I've just presented will help fill in some of the societal blanks you may have. If you want more detail than that, you could look into a lot of other things like microbiology, what does a creature breathe in and out and how far from the norm can it go? How hot or cold can the inhabitants get? What viruses are present, etc. Ben Bova wrote a book called World-Building. It might help you. I hope I did. ]
[Question] [ Joe is an average bloke, who has a passive superpower that he's lived with all his life. People believe everything he says. Implicitly, unquestioningly and absolutely. If he says that black is actually neon purple, people within earshot accept that as a natural truth. If he then recanted his statement then black would be black again. This has certain advantages ('But this meal is on the house, waiter!'), but Joe wants to live a normal life (for a variety of reasons, one of which is evil assassins). How can Joe avoid accidentally using his superpower in everyday life given that even seemingly innocuous statements like 'Good Morning' can completely change the mental state of those around him? Joe can't turn this power off, and wants to be able to live as a normal western adult male, so taking a vow of silence or retiring to the Rockies in a tent aren't options. **Edit:** For the avoidance of doubt: This applies only to spoken and heard communications (the deaf are immune). On the other hand: For the purpose of combinations such as pointing and speaking, anything that someone would think to themselves 'that's obviously a lie' when it's said/done by non-Joe, believes it implicitly when it's said/done by Joe. If the person has misheard or misconstrued what Joe said, then they implicitly believe what they heard/understood, not what Joe intended. If what Joe says just doesn't make sense (for example: Patent explosive donkey muffin discombobulate.) then confusion is the response that will occur, not attempting to parse the sentence into 'truth'. Now I want a Patent explosive donkey. [Answer] **Just tell the truth - and be specific.** Joe's superpower appears to be a problem in one of two types of situations: 1. He says something that isn't true ("I am a green stegosaurus!"). 2. He says something that could be interpreted in different ways ("Good morning!"). Joe can control things in the first case by simply always telling the truth. I can't think of many situations in which this would be problematic - most of us don't claim to be dinosaurs on a daily basis - except in ones where he might have to tell white lies. Lying then won't cause huge problems. Besides, there are situations where having people believe white lies could be handy. For example, Joe Jr. will finally believe his dad when he's told that that red liquid isn't the actor's blood, but ketchup. The second case can be averted by saying an entire sentence. For example, people say "Good morning!" to one another as a greeting. If you make this a full sentence, though, it can be thought of in different ways: * "I hope you have a good morning!" * "I think it is a good morning!" * "It *is* a good morning!" All Joe has to do is be specific as to which of these he means. [Answer] He could train himself to turn every statement into a question: "Good morning, isn't it?" [Answer] **Joe should go into politics.** The shock of having an honest politician may be a bit much, but people would accept it. After all its "Honest Joe". I have to admit, that I am assuming his superpower works over television, etc. and does not work only in his personal presence. Joe is no longer accidentally using his superpower. He is using it intentionally to change the world for the better (hopefully). As for his public policy speeches. He should be utterly dependent upon the teleprompter so that his words are carefully scripted to have the exact effect he desires. In private he can instruct his advisors, etc. to tell me what you really think, don't worry about disagreeing with me. In fact he could get the best and brightest to advise him specifically about how to best use his superpower. When caught in an impromptu press conference, etc. He could still control the message in acceptable ways. To dodge a question about current events, "I am not sure we know all of the relevant facts at this time but I am following the events and share your concern, next question please." or "I am not taking questions on this subject at this time" or "I don't have time to answer this right now" Best thing is, since even the reporters trust Joe, no controversial followup questions will trouble him. Politics is about messaging. How do you say something to accentuate your message and not "step in it". Pick abortion as a an example, few things are more politically controversial in the US. * As a Democrat: "I think abortion should be rare but legal. But ultimately at some level it is wrong to force a woman in what has to be a very personal decision." * As a Republican: "I think abortion should only be legal in very restricted cases. Although I am very sympathetic to the women carrying an unwanted child, I cannot agree that killing an innocent baby is something a moral people can endorse." I believe both of these statements are a pretty accurate representation of the party positions. Coming from Joe, both statements are perceived as reasonable by everybody. Coming from Hillary Clinton or Ted Cruz, they aggravate the opposition as wrong-headed and hypocritical. Joe can memorize the stock phrases he needs to answer most questions to convey his precise intent. He can deal with other question using his dodge phrases until a better opportunity to answer carefully arises. Now, if Joe is good and wise, we can have the best politician possible. If he is evil or foolish it could be very bad for his constituents. If you have a superpower and don't use it you are simply wasting an opportunity. This waste will very likely eat at you as a failure of character (if good) or failure to take advantage (if evil). Avoiding the power will cause Joe harm, and logically if Joe is good, harm others by not having the benefit of his beneficence. --- I thought that some people would not consider the life of a politician to be normal, but did not address it. I know some politicians personally. They seem to lead what is a very normal life. They love their spouse and kids, enjoy their kids and friends. Maybe they go to a ball game occasionally including their kids playing sports. Perhaps at the level of the President of the US you are necessarily more isolated and thus not living a normal life. So maybe Joe will not run for the top office, maybe he limits his office to mayor of a large city. On the other hand, if you get used to being mayor, maybe governor seems normal. And once you get used to being governor, becoming president seems normal. I know I've had this conversation with one of my politician friends and this is pretty much how he described it -- i.e., initially he was more impressed with the office and its responsibilities, but after a while it was just normal and the other senators no longer seemed above him in terms of being beyond just normal people like him. --- I considered other professions, but eventually decided upon politician. * Preacher * Salesman * Trial Lawyer * Mediator * News Anchor * Public Relations * Inspirational Speaker All of these would certainly be different with Joe's condition. I would certainly welcome a careful case for any of the above for being a better choice or something that I did not consider. [Answer] ## Learn [a sign language](https://en.wikipedia.org/wiki/Sign_language) and never speak. Since this uses manual communication we evade the fact that: > > People believe everything he says. > > > This strongly reduces accidental triggers of his superpower. He would still need to talk to get proof that he's disabled (mute) by stating that fact to the necessary people (health specialists like nurses & doctors). With this proof he can then request official assistance (like requiring a dedicated translator for when he's following a meeting or symposium), which should strengthen his cover. [Answer] All Joe needs to do is say "I will never accidentally use my superpower," and he won't. [Answer] To avoid turning anyone to his point of view, Joe should never express opinions as facts but only as an opinion which applies to him personally. Example: *"Strawberry ice cream tastes disgusting Strawberry ice cream tastes disgusting **to me**."* Someone hearing this won't be convinced that strawberry ice cream is disgusting to *everyone*, they will only be convinced that it is disgusting to Joe specifically. Their *personal* opinion about strawberry ice cream won't change. Another option for Joe would be to counter his ability by constantly injecting statements into his everyday speech which tell the listener that he isn't trustworthy. Example: *"Strawberry Icecream is disgusting, but you know I don't have a common taste. We should buy something else, but you should not trust me on this. Why not buy chocolate ice cream instead? But remember, I am a liar."* This way of speaking might seem unnatural to an unaffected person, but those affected by his ability might not notice it. Still, Joe will have to careful balance the use of these statements. Too much, and the person will start to develop a subconscious impression that Joe is not trustworthy and feel an aversion to him. Not enough, and he will start controlling people. It will take decades of practice until Joe finds the right balance. But over time this strange manner of speaking might become second nature to him. --- Still, the ability to convince everyone he is speaking the truth and completely override their personal sense of reason is practically mind control. It is a very powerful ability which is very easy to abuse. Joe would have to possess an overwhelming amount of self-control and an extraordinary sense for morale and ethics to not get corrupted by this power. This is something people aren't born with. So he would have required a strong authority figure in his youth to get him on the right path. If he was born with his power, no such figure could have existed in his life, unless they were immune to his ability. [Answer] Joe should say a paradox (such as "this sentence is false"), smile, and walk off. Then we'll find out how super Joe's superpower is =) Edit: For those who are not familiar with what a paradoxical statement is, its one which cannot possibly be true because it contradicts itself. Thus his statement could not be true. A paradox would be one of many places where Joe an test regions where his superpower cannot go. It may, in fact, destroy his ability completely! [Answer] It's going to be pretty hard, if not impossible, to live a normal life unless he can figure out what his weakness is and neutralize his own power. It's pretty close to an absolute power over others, which would corrupt just about anyone. Few things he could try, like shouting himself hoarse and see if it still works. Breath helium or sulfur hexafluoride and test it. Try it while connected to a MRI or other brain scan and see if a specific area lights up. Worse case join the CIA and use the power to eliminate ISIS and other threats by simply telling them that killing is wrong. [Answer] He could become a reporter. Then he can truthfully tell all the lies he wants to - or has to - accurately reporting the words of others, with appropriate attribution. I heard some amusing examples of this happening, listening to Radio Moscow during the "glasnost" era and the fall of the Soviet Union. During the Gorbachev era they were trying to learn new ways of reporting the news - and I think, actually making an honest effort not to be pure Soviet propaganda... (One story of that time was about the Hungarian police having to give up their faithful Ladas ... all the crooks had BMWs...) Then one morning came the big news story (on the BBC) that Gorbachev had been deposed by the hard liners, so I wondered what Radio Moscow's take would be, and I heard ... solemn classical music. Just the music... Then, and for the next few days, they reported official statements, attributed to the Politburo. It was clearly impossible for them to voice any dissenting opinion : on the other hand, they would be negligent if they didn't report what the American president said about the situation ... so that's what they did - attributed to him, of course. Three days later, when the hard liner's coup collapsed, they were finally able to report about the tanks parked in their back yard for the duration... [Answer] This answer tackles precisely what you've suggested in your question - How can Joe cope by with living a life where anything he says becomes -> true. **What his power does:** His power essentially makes things true. Whenever he says something is X, then, even if something is Y, it becomes X, and thus it's true. **How to circumvent this power?** He deconstructs sentences. Wishing someone good morning, an happy birthday, a good life, etc.. are easily prevented. "Good Morning" can be a statement, and thus using his power, however "I hope you're having a Good Morning"/"I wish you an happy birthday" wouldn't be using his power, as he's expressing something that affects him, and him alone, at least, regarding his powers (you could argue that wishes could come true due to a 3rd party). Then there's arguments. Whenever he has to express an opinion, he would force others automatically to accept his opinion, wouldn't he? He wouldn't. Once again, check out what the power does. People believe whatever he says. "The box is purple" would be an assertive statement which would make people believe that the box is indeed purple, however, "I believe the box is purple" would also trigger his powers, but instead of making people believe that the box is purple, it would make people believe that Joe thinks the box is purple. In sum, he can live an happy life if he sticks to referring to himself whenever he talks, "I think", "I wish", "I would" are three statements that would allow him to live a normal life. BUT... He won't be able to use sarcasm at all. [Answer] Well why don't he just tell people : > > I am not always telling the truth, and you got to use your own opinion to determine whether I am right or wrong. > > > He then just have to never disprove this sentence and this should go well. [Answer] So the deaf are immune. (And apparently assassins.) Is Joe himself immune? Could he with self-hypnosis or a helpful hypnotist convince himself it was simply a coincidence that everyone agreed with him? Isn't what he wants "a normal life" merely the illusion of a normal life? Perhaps once a week he tells himself in the mirror "I am just like everyone else" until he rediscovers his superpower by observation. Rinse and repeat. [Answer] One thing he could do is to state everything in terms of hearsay. Instead of saying "coffee is good for you" he could say "I heard them say on TV that coffee is good for you". Instead of "the price of gold is going up", he could say "My broker thinks the price of gold is going up". And so on. Thus Joe is not using his own magical credibility, but allowing the listener to judge by the credibility of the attributed author of each statement. ]
[Question] [ In the 1955 science fiction short story, The Tunnel under the World > > a chemical plant explosion kills all the inhabitants of a town, whose consciousnesses are then uploaded into miniature robots living in a replica town on a table top for the purposes of research into advertising techniques. > > > How would I know if my consciousness had been uploaded into a miniature robot living in a replica town? What would be the most obvious difference living at the 1 mm scale instead of the 1 m scale? Diffraction effects with my tiny pupils? My experience of the viscosity of the air around me? Regulating my temperature? [Migrated from physics.stackexchange where it was too broad] [Answer] [![enter image description here](https://i.stack.imgur.com/LlBj4.jpg)](https://i.stack.imgur.com/LlBj4.jpg) I never read that book, but if there is water in that universe then i would guess it becomes obvious when you try to drink it due its viscosity. [Answer] Gravity provides an acceleration of roughly 9.8m/s2. If you're normal height, something free falling for one second would have to fall about two and a half to three times a person's height. If you're just 1mm tall, the object would fall 4,900 times your height. Now that ignores drag, etc. But yeah, anything you drop would seem to hit the ground really, really quickly (unless you were somewhere with notably lower gravity than Earth). [Answer] Natural materials would be the biggest giveaway, the most obvious being wood. The surface textures are quite fixed in size and you're going to be seeing vast sizes on woodgrain where you're expecting fine patterns. Other materials, like cloth and paper, will be quite hard to work at those sizes, suddenly a fine material becomes a massively thick and heavy one. You can't just scale down materials with natural fibre thicknesses, these things are going to stand out. [Answer] You'd notice quite a number of changes pretty fast if you were shrunk to that scale, some of which you have already mentioned, and another big one being the square/cube law - you'd find yourself much faster and stronger relative to your body size. However, since it isn't really your biological body, some of these differences might be mitigated by the robot's design. The air viscosity could be altered by containing the town in a bubble with a controlled atmosphere (presuming that the robot was made to breathe in that atmosphere). Light would behave differently, but a clever scientist could program your eyes to respond to shorter wavelengths and then paint everything in the ultraviolet. And of course, the robot could be made proportionally weaker so that you wouldn't notice the square/cube effects, as well as generate more heat (or simply function and respond to colder temperatures) than a biological organism of the same size. If they went that far, it would be hard to notice the difference. But that would be a lot more work than just making a scale replica of a town (although possibly not much more work than uploading brains into tiny functionally human robots in the first place). Honestly, if they want to research advertising techniques that badly, they should just skip the robots and upload your brain straight into a virtual world. [Answer] ## [Brownian motion](https://en.wikipedia.org/wiki/Brownian_motion). I am surprised this hasn't already been mentioned, but at small scales, the effect of random motion of fluid molecules will play an increasingly large role on the motion of objects. Instead of staying roughly stationary, you will see moderately-sized objects in the world moving randomly for no apparent reason. Brownian motion is usually observed for micrometer-sized objects, which means anything the size of approximately 1mm in size in your scaled world will start to jump around all the time with no obvious sources of motion. This is a physical phenomenon which will occur as long as the experimental setup is not evacuated into a vacuum. As such, it will be impossible to prevent except by completely preventing the robot mind from recognising it, but at that point it will probably easier to run a simulation of the world instead. ## [Diffraction limit](http://www.microscopyu.com/articles/superresolution/diffractionbarrier.html) of light. Vision will be restricted by the diffraction limit. Assuming that objects have similar absorption/emission wavelengths and the eye is still interacting with light of similar wavelengths (400-700nm), the diffraction limit will greatly hamper vision. The human eye has a [numerical aperture of 0.23](http://www.globalspec.com/reference/15062/160210/chapter-10-2-1-resolution-limits-of-conventional-imaging-systems). Since the eye will be scaled appropriately, the NA should not change while being scaled. Using the diffraction limit $d = \frac{\lambda}{2×NA}$, we can find that the maximum resolution of the eye is actually ~2.17 times the wavelength. Therefore, the eye cannot resolve any object roughly 1µm in size (real life) or 1mm in size (scaled), depending on the wavelength. This will cause issues when reading small text that is also scaled. [Answer] I've read the story, I think it's a good story, but if you think it through, its plausibility is debatable. I don't recall if the writer ever said exactly how big the robots were. I was picturing them as maybe 1 foot tall, i.e. much bigger than 1 mm. The closer they are to normal size, the less dramatic any scaling effects. As others have noted, some things would be fairly obvious, like objects would fall too fast, water puddles would be too thick, the air would seem more viscous. You'd probably notice some square/cube effects, like hot objects would cool off too fast, and you could put more weight on a table or chair without it collapsing. If you had the equipment and expertise and measured the speed of light you could prove it definitively. I don't know how chemists determined the number of atoms in a mole, but if you could reproduce that you could prove it. Etc. We'd have to ask how far the builders went to deal with such issues. Maybe they didn't give the robots real water but some chemical that behaves in a way that "looks right". (And of course if the robots drink it, they're programmed to think it tastes like water.) Presumably the robots are built so that their strength, speed, etc "feels right". The acceleration of gravity would be tough to work around as long as Tiny Town is on the surface of the Earth. But if you get most things to feel right, maybe nobody notices a few odd things, or if they do, they write it off. Of course, the whole point of the story was that people just woke up one morning in their robot bodies in this artificial world. Presumably they had no reason to doubt that this was not just another day. So ... how odd would things have to be before you started sayng, "Hey, this is weird"? Sure, someone with scientific expertise who suspected he had been miniaturized like this could think of dozens of experiments to test the theory. But would your everyday experiences be enough to make you ask the question? If you were shrunk to 1 mm, I suspect they would be. But if shrunk to 1 foot? Maybe not. It's really hard to say. Like if I woke up one day and noticed that, say, a book I dropped fell faster than it should, would my first thought be, "My consciousness must have been uploaded into a miniaturized robot!"? More likely I'd say, "Hey, that's weird. Is that normal? Is there something funny about this book? Oh well, anyway, got to grab some breakfast and get to work ..." Even if there were many things, I'd probably think, "Wow, I'm just really slow today" or "Maybe I should see a doctor" or whatever before I'd think of being turned into a miniature robot. And remember they only had one day to think about it before their brains were reset and they started the day over. I suppose we could postulate that the robots are all programmed not to notice any discrepancies. They could be programmed to think that the speed at which objects fall is what they've always seen before and this is perfectly normal, etc. In which case the answer would become, It's impossible to tell, because you're programmed not to. When I read the story I wondered: if the builders of Tiny Town had no moral qualms about uploading people's consciousness into these robots and using them for these experiments, why not just cordon off a real town of real people and do similar experiments? Indeed they wouldn't have to cordon it off, just run their different advertisements and observe what happens. Well, okay, with actual people they couldn't do the daily reset to get a controlled experiment. But it would seem a whole lot cheaper and easier. If they have the political pull that they can requisition the bodies of all the people killed in this explosion and upload their consciousness, surely they have the political pull to get whatever laws they need passed to let them run their advertising campaigns in one little town. Etc. [Answer] In a spin from Separatix's answer, my guess is water (or any other known fluid, but there's none better known than water by most people). Water behaves wildly different at this scale : insects routinely can transport bubbles of water without container by just holding it. I don't know the physical details, but I doubt you could get a container of 1mm or smaller to hold water in the same way something at our scale does : just due to capilarity, the water will "climb" the walls of any container for a small distance. But at this scale, the distance will be very very big. And puddles of water can very easily be way bigger than a few mm. You will very easily see there's something wrong when you see water holding out in a giant bubble instead of spreading on the floor. Freezing water also do the trick : snow flakes are of rougly equal size and you would be able to see them way bigger than usual. [Answer] Some things you'd notice quickly: * The absence of nontranslucent paper. There's only so thin you can make wood pulp so scaling paper down doesn't work. (As a broad physical effect, the color intensity of all diffuse scatterers, like colored glass drops sharply because the light path length in the material is reduced.) * Other have danced near this -- you can't escape a swimming pool; when you bathe, you drown. The apparent change in water's viscosity and surface tension causes these effects. Just as you can see insects moving freestanding droplets of water, you can also see them trapped inside droplets by the merciless surface tension. Water "wets" you (meaning it spreads as a thin layer across your surface). This is especially true when you add a surfactant, like soap or detergent. Consequently, when you try to take a bath or shower, you are covered in a smothering layer of water that you can't remove. * Diffusion is way too fast (no time correcting in software) or way too slow (with time correction in software). Say you have a grandfather clock so you *know* the period of a pendulum about $1 \,\text{m}$ long. This goes as $\sqrt{\ell/g}$ where $\ell$ is the length of the pendulum and $g$ is the force due to gravity. If you make me $200$-times smaller, a scaled pendulum runs $\sqrt{200} \approx 14$-times faster. However, diffusions scale as $\Delta x \sim \sqrt{t}$. If my software is modified to make time seem to run $14$-times faster (so my pendulum seems correct), a diffusion will only proceed $\sqrt{14} \approx 3.8$-times as far as it normally would. So either way, diffusion has changed. (Any time you can compare two physical processes that occur with different *powers* of some parameter, you can detect this sort of scaling.) * Things freeze too quickly -- this is square-cubed law again. Likewise, things cook too quickly. "Never thought I'd need a decimal point on the microwave." * The texture of meat is too coarse. * Radio antennae are now 200-times too short. Ham radio operators have a pretty good idea how long $0.5 \,\text{m}$ is (for a quarter-wave antenna in the $2 \,\text{m}$ band). Regardless of what you do to my internal clock, you can't make the electrons in the antenna resonate as if the antenna were $200$-times longer. Radio transmission to/from radios that have been scaled will work (assuming no obvious sources of powerful interference at the real frequencies, like airport radars, television broadcasts, et al.) but if either the transmitter or the receiver is "in the real world", the wavelengths won't match. [Answer] [smallest possible flame](http://sci.chem.narkive.com/OaMpc1lo/smallest-possible-flame) A "candle flame" would look disproportionately large (if you manage to light it). Rate at which a material burns or even transfers heat will seem faster (on our normal size a person expects a candle to burn for several hours). A 3mm traditional size flame (which seems to be the smallest possible traditional flame) will look strange to a 1mm size human/robot. [![enter image description here](https://i.stack.imgur.com/XTNYK.jpg)](https://i.stack.imgur.com/XTNYK.jpg) [Answer] The problem is that presumably the minature androids could be *programmed* to not notice such *obvious* inconsistencies; and any that they do encounter will be corrected for after the regularly scheduled memory reset. > > (Indeed the plot of the story was that inconsistencies were only noticed when one deviated from its regular activity schedule and started exploring parts of the model that weren't as accurately rendered.) > > > One will not notice the surface tension is wrong, or such, when there is no actual water and it is just an hallucination provided by *augmented reality* filters.   After all, the miniature androids don't need to actually eat and drink; just simulate it. Still, if someone has the tech to do this, why not just use full on Virtual Reality to run the simulated city?   It would take up a lot less space than maintaining a scale model anyway. Of course, **Tunnel Under the World** was written well before the concept of Virtual Reality simulations was developed; in a time when sci-fi writers could envisage miniscule androids capable of emulating human thought, but strangely were still imagining super-computers as needing to occupy an entire city block. [Answer] One should note here that the macroscopic scale is so extremely far away from the atomic scale, that the physical world we experience can to a very good approximation be described by mathematical laws that don't contain an explicit length scale. While they are not invariant under a length rescaling, a change in length scale can instead be implemented by adjusting the parameters that describe the world at the macroscopic scale. The way you need to change the parameters so that the physics changes in the same way as what you would see had you changed the scale, is called a renormalization group transform. This is a very powerful idea in physics, the application to theory of phase transitions of this earned the Nobel Prize for [Kenneth G. Wilson](http://Kenneth%20G.%20Wilson). So, as pointed out in the other answers, the World will look different like e.g. that the surface tension of water will become far more relevant. However, everything you see will still look like the old World but where the parameters like surface tension, viscosity etc. have been adjusted. ]
[Question] [ I've got a group of magical people living mostly incognito in an ancient society. They look and act exactly the same as regular people, but they are really magicians, and a side effect of having those powers is that they are two times as dense. E.g. a lithe woman who looks like 50kg/110lbs would really weigh 100kg/220lbs. They've got twice the muscle strength to compensate, but the mass is still there. It is congenital, they are born that way (perhaps even since conception). What are things people could notice about them? It's not enough extra weight to make them fall through floors, but sitting on one end of a boat betrays them as it leans over more than it should. I think the extra inertia would also matter in some places, but I'm not sure where. [Answer] **They can't swim.** Normal humans are just barely buoyant enough to float in water. We need to generate some hydrodynamic lift to get far enough out of the water to breath. [The average human body has a relative density of 0.98 compared to water](https://en.wikipedia.org/wiki/Swimming). Your humans would have a relative density of 1.96. That means while a normal human swimmer just needs to create a little bit of hydrodynamic lift in order to get their face high enough out of the water to breath, your dense humans would need to support half of their whole body weight with swimming motions. To get an impression of how difficult that would be, imagine trying to keep your head above water while there is another person of the same weight as you standing on your shoulders. Even if you were twice as good of a swimmer, that would be impossible. Normal people can't do that and your people wouldn't be able to do that either, even with twice the strength. They would sink like rocks. It would be next to impossible for any bystanders to get them back to the surface before they drown. For that reason you will likely not get them into a boat. They would know that being so close to deep water would put them in mortal danger. **You would notice if they compete in contact sports** In sports like wrestling or rugby, a trained athlete quickly learns to judge the momentum of their opponent by how they look. This skill is crucial if one wants to succeed. When their opponent is twice as heavy as they should be, they will notice. A professional might even notice when they observe a match where one participant is heavier than they should be. [Answer] **A number of common situations could give them away.** If you ever paid attention to people getting in and out of your car, you notice that it shifts by noticeably different amount depending upon the weight of the person. Maybe the fact that I notice this makes me a bit of a rarity. But there are other small things. How loud a floorboard or chair creaks. How much a cushion or mattress compress. Again, these may be subtle, but the brain is good at pattern recognition -- and although you may not notice these things in in normal people, does not mean you would fail to recognize the exception to the pattern for high-density people. Of course, early in-life people weigh babies, hold them, and even pass them around to friends and relatives. This would be instantly noticeable and all high-density people would be detected as infants. If high-density people don't realize their condition, they would be detected in medical exams. Or broken toilet seats, chairs, etc. as they would not expect to cause damage by simple actions. If they try to conceal their condition, it will be harder for others to detect of course. [Answer] In addition to the answers listed, here are some more things that these people will need to be careful about, otherwise it could put them in a situation that could result in their exposure: ## Speaking Their vocal cords are also twice as dense. The [length, size, and tension](http://mentalfloss.com/article/50360/what-determines-what-your-voice-sounds) of the folds in the vocal cords affect the pitch of ones voice. It is doubtful that the tension will go unchanged as a result of the density doubling. Unfortunately I could not find any studies on what happens if you change the density of the larynx. So, I cannot say for sure if it would cause them to naturally have higher or lower pitch voices. For example, if the density increases the tension, then it will cause their voices to have a higher pitch. If they get scared or excited it would increase the tension even further, resulting in them hitting some rather high pitch notes you would not expect a person to reach (specially if it is a man). ## Getting Their Hair Cut Their hair is going to be twice as dense as regular hair. Any barber or hair stylist will notice something is wrong. Specially when their scissors or clippers start having trouble cutting through their hair or become blunt faster. They might not be able to conclude that the person is twice as dense, but they will know something is different with these people. ## Corset and Brassiere Problems Corsets, brassieres, and other types of clothing are designed and intended to provide women with support. Unfortunately for any women that is twice as dense, means their clothing will need to provide twice as much support. As such the extra unexpected weight could damage corsets and cause more flimsy outfits to struggle and break leading to wardrobe malfunctions. This would not directly reveal them as being more dense, but it could put them in a situation which could easily lead to their discovery if someone tries to help them. [Answer] Besides what everyone has already said: **their steps would be *generally* louder**. They would impact the ground with twice the energy on each step, for the same footfall used by a person of regular density. Also, they would be putting twice the pressure on the ground when standing. **Their feet will sink a little bit on beach or desert sand. Their footprints will be deeper in any soil.** And on snow, depending on the environment, they might sink anywhere from less than an inch to more than their full height depending on how compact the snow is. [Answer] They would also likely **need to consume a fair chunk more food** to account for the increased energy needed to move. You mentioned the extra inertia, well coincident with that is larger amounts of energy needed to move, such as in kinetic ($\frac{1}{2}mv^2$) and potential ($mgh$) energy. Or else they'd become tired and start losing weight/look emaciated. Certainly the existing range in metabolism may make it difficult for many notice, similar to [Gary's answer](https://worldbuilding.stackexchange.com/a/114680/25271). Indeed I've certainly had "smaller" friends who ate nonstop, weren't all that active, and somehow didn't gain weight. But it might at least make people suspicious. You could use [this calculator](http://www.calculator.net/calorie-calculator.html) to get a rough idea of how much additional energy consumption would be needed. [Answer] Physical contact between humans is not rare, especially on sports teams but also in other social situations. * High five: normally the momentum of both people's arms cancels out. It might be possible to simulate a less dense arm by using your muscles, but even this could give you away. A simple hand-shake might not be a give-away if the person is well-practiced at making their hand easy for the other person to pump up and down. Sometimes a handshake starts with a slap or hand-clasp that could give it away. * Hugs, especially a "man-hug" that starts with a handshake and involves pulling the other person in until you bump shoulders. **The other person's inertial mass is readily apparent.** [Illustration from this article: ![enter image description here](https://i.stack.imgur.com/uX8my.jpg)](http://www.omaha.com/living/the-art-of-the-man-hug/article_e2034b0f-77b4-5ae2-9be4-38ced1727443.html) Holding someone's shoulders as you greet them with air kisses next to their cheek (like in some parts of Europe) might give things away. The more touchy-feely the culture, the harder it will be to go undetected. * slap someone on the shoulder or give them a friendly push: if it's at all forceful, you expect their body to move some. * *non*-friendly pushes or fighting: it will be very obvious if you punch, push, or kick someone. Physical play between children might not be a "fight" per-se, but any kind of roughhousing will be a giveaway even to other children unless they're *very* young. * dancing with a partner: you don't push/pull your partner around the dance floor, but I think you would notice the difference just touching them while they move. Any "spin your partner" move where you hold on to each other and spin around a common centre of mass would be a dead giveaway. Even in non-contact sports like Ultimate [frisbee], it's not rare to accidentally bump in to someone. A factor of 2 mass increase will be very obvious. You'll bounce off and they'll barely move. At walking speed in a crowd, you sometimes jostle with other people a little bit, and even that could be enough to notice something was weird. **If a dense person is trying to stay undetected, just being physically near other people is a big risk. You never know when one will bump into you accidentally or touch you on purpose and notice the difference.** If you slip and someone tries to help catch you, they'll notice. If someone *thinks* you slipped or might need help, they might grab your hand and notice that it has twice the inertia it should. [Answer] **They will sink like a stone in water.** I don't think a doubled strength could fully compensate for a doubled density, as the buoyancy force is *not* doubled. If they can swim at all, it will be obvious that they're making a huge effort just to stay afloat. Of course, knowing that, and also knowing about drowning, they'll avoid deep water like lava. Especially around outsiders. They won't stand out for it either, since "I don't know how to swim" is a perfectly valid excuse. But any accidents with them falling on water will surely reveal that they sink unnaturally. [Answer] You also need to think of things like body heat. You'll have the same surface area through which you emit heat, but you'll have muscles -- and I assume other body/cell functions -- that are emitting twice as much heat. Someone very near to or touching you would feel the unnaturally high heat. Perhaps your metabolism could somehow be twice as efficient, but... (Also, if your metabolism is higher, even things like breathing would be an issue, since you'd need more oxygen but you have normal-sized nostrils and lungs, so you might be "out of breath" a lot.) In terms of your remark on inertia, imagine bumping into a normal person on a sidewalk -- a situation where extra strength wouldn't help them because you wouldn't have time to use that strength to oppose your inertia. People would naturally assume from the force of the impact that you purposely put your shoulder into them. And this is assuming you possibly *could* use your strength to modify the situation, so imagine a situation where you're ballistic -- jumping, falling -- where no amount of muscle action could compensate. (This would apply to accidental impacts with anything, not just people, so you would be more likely to knock things over or destroy them if you bumped into them.) You would also wear out horses pretty rapidly as an adult. I don't think horse stamina falls off linearly, so you'd wear out a horse more than twice as fast as someone else of your size. And your horse would generally be slower than those of any companions. [Answer] In the movie Shallow Hal, Jack Black's character sees a woman who is extremely over weight as skinny an petite. Some things the film did to show his perception of her wasn't accurate- * Getting in to a car, it sinks much more than her weight would suggest it should. * A chair that looks like it could easily manage her weight fails under the stress. * After she gets out of bed, Hal rolls over to where she was laying and falls into a deep recession in her mattress. [Answer] **They would eat a lot** You could expect these people to need many more calories than a normal human. It takes energy to start and stop the additional mass, even if the enhanced muscle ability make the movement look completely normal. Additionally, even at rest, muscle take more calories to maintain than other tissues in the body. I imagine the enhanced muscle would need a similarly enhanced flow of calories in upkeep. *Net result*: these people probably spend much more time eating than others, or possibly would only eat calorie dense foods *Note*: a similar effect might be found with their breathing. Even a professionally athlete is going to get tired and breathe heavily if they carry around another person's weight all the time. Lung capacity / efficiency might increase to compensate, but if it plays out like this, I think it unlikely that these people would spend much, if any, time at high elevation where the air is thinner. **Abnormal body temperature** Or at least, that's how it would likely feel. I'm interpreting twice as dense to mean that there's literally twice as much physical stuff in the same space. This would mean there is effectively twice as much surface area for purposes of thermal transfer. *Net result*: with any physical contact (say, shaking hands, for instance) both parties would feel any temperature differences much more acutely. It's possible these people would have constant hot/cold hand syndrome, or at least be perceived that way by normal people. **No static electricity**(possibly) Higher material density decrease electrical conductivity, all other thing bring equal. (I'm using compression of air as a logical reference point, so this might not even apply since people are made of solids and incompressible fluids). These people would effectively be electrically insulated. *Net result*: tasers, Van der Graff generators, etc might not work as well on these people. It could also protect them from electrical magic you have them wield, if that's a thing in your world. **They don't get sick** Traditional diseases rely on germs bring suspended in a person's blood or cells. If these people are twice as dense, this simply would not happen. It's like the swimming problem in the other answers, except in reverse. Normal diseases would simply float and collect in certain points of the body where they would be quickly eliminated. If magical traits are at all genetic, you could expect their immune system to eventual center around (or even create) these points. Perhaps the magical community have their own unique set of diseases that normal people can't get? **Deep footprints** This one is pretty simple. Heavy people would displace more dirt/mud when walking **Biological waste** If everything in their bodies is twice as dense, it's fair to assume that their... excrement would be as well. This would create a problem if they needed to use modern plumbing, as it's entirely possible moving water would simply not have enough mass to clear a toilet bowl. *Note*: hair is interesting to consider as a non living component of a person. Either the hair is just as strong as normal (limiting it's length due to the extra weight) or it doubles in strength like everything else so it would look sort of normal. Sort of, because if it's denser, it wouldn't blow in the wind as much as a normal person's. It's possible normal people would want to use it for making rope, given its strength. Or if it is just denser but not stronger, normal people might grow their own hair past that point to prove, immediately and visually, that they are not magical (useful for a diplomat, say for instance, since the couldn't then be a magical assassin) I'm sure there's more, but that's all I can think of off the top of my head. Cheers! [Answer] You would notice the difference in children at a playground. Almost all playground sets use weight as a factor of play with the exception of the climbing sets. Sets like the swings, seesaw, rope bridge, bouncy horses and the roundabout. You could see the difference if a children who was twice as heavy played with a normal child on a set. A person with a keen eye could even spot the difference in the sand as the children ran and jumped. Children could also not play contact sports like soccer, football, rugby or basketball without revealing their weight difference. If a segment of the population was prosecuted for this difference, then it would be interesting to see how places like playgrounds would change. Instead of being an open place at the park and welcome to everyone. There might be police there keeping an eye out for heavy children. We might find that strange, but for parents living in that world it might be a necessary thing to ensure their children are safe. [Answer] ## The every day sign, especialy in an ancient time. ### Chair, Ladder, and Car: Every things is build and design with a weight limitation. Take a good old wooden chair, A average man of 80Kg will not break a chair by sitting on it. A Dense Joe will easy break it, especialy if he give it a little swing. For a 50Kg woman the sign will be the floor wear. In ancient time floor were wood or dirt, this will be easly noticable. For bench, once a normal man sit down, a dense one can catapult him just by sitting to fast or getting up too fast. If he goes slowly you will notice the weigth simply by the bench vribration and bend. On a bench you can notice if a kid(light) or an grown up sit on it even with your eye close. For car and transport, this will be fun. They will either break the horse back or make a noticable shift in the car balance. Old vehicule don't have the sweet car suspension we have now. And even car suspension will give them away, same test for bench close your eye and ask someone to sit next to you. You should be able to tell witch is 50kg or 100Kg. Ask Dense Joe to use a teen bicycle for fun. In general every they use will wear faster, If those dense live together like a familly they should not invite people home. When we build thing we trend to build them so they can be use in normal usage. 2 people usage instead of 1 is more than -50% life time, it could be imediat failure. Things like ladder won't like your Dense Joe. ### The one that don't Knock: They also never knock on door. You can have physical expectation when earing a door knock. You will notice that the 50 Kg girl knock like a 100Kg man. ### Dense Joe don't drink booze: There is nothing that test its own inertia on object like a drunk man. Any one that even encounter a drunk Dense joe can tell: "You don't pick them up." ### Dense Joe sleep on the floor: He will tell you that it's good for hes back. But Dense Joe simply break the bed every time. (50kg+80kg)x2 in the middle of the bed. [Answer] They'd ask you to speak louder. Their denser ear and bone tissues would require a higher sound frequence in order to perceive clearly our speaking. Also, while eating, they should pay more attention if eating meat with bones. They could accidentally shard a bone and end up with mouth wounds. [Answer] Any time they need to get on a vehicle—in an ancient society, probably some kind of cart or chariot—or ride a horse, it will go much slower than it should. And if you know how much your own horse can carry, you’d at the least be worried that something’s the matter with your horse. In any situation where you have to balance a load, say by putting two people the same size on opposite sides of the cart, it becomes obvious that it takes twice as much weight as it should. Someone who knows the strategies wizards use to stay inconspicuous might therefore look for the person who always makes very sure to sit in the middle of the wagon, not on either side, but also to sit directly over the legs of a bench, not in the middle. [Answer] They would need to eat more for the same growth (unless the extra weight magically clings to them upon absorbtion in the body). Besides swimming, they would have trouble jumping/falling and have a lot of problems with steep stairs or climbing up/going down. Even with double muscle strength and equivalent bones, the impacts would be immense and because they have twice the mass but the same shape they would accelerate to terminal velocity twice as fast (and have higher terminal velocity), so their bones and muscles would need to be about 4x stronger for the same height jump/step. They would basically move around the world like geriatrics. A simple stumble can break their arm or leg. A crash with a car (or even a simple bicycle) would be lethal far sooner. In reverse, it takes more force to start moving their body so you need something bigger to hit them and get a damaging response. Even that has downsides as you'll absorb more energy in less time as well. [Answer] I thought I could write something about how changing direction (walking around a corner) would look weird, but turns out that since F = m \* a is a linear relationship between force (twice as strong) and mass (twice as dense), so they should be able to accelerate/decelerate just as normal people do. They also likely won't skid when trying to slow quickly, since friction is calculated as F = u \* m \* g, so the available friction to excert the force needed to decelerate them also grows linearly with the mass. Thus, the only new thing that I can still mention is... That they would buy very sturdy shoes (nothing with a middle sole that would be compressed by their extra weight, ruining the shoe quickly, or a sole profile that would suffer similarly) and would have to replace them more often than normal since all that extra friction they need to accelerate/decelerate with every step will eat the rubber quickly. So, people could notice strange (footwear) fashion choices, and a quicker-than-usual (for this kind of shoes) need to replace them. Might be something that makes for an amusing quirk to their friends :) [Answer] ### Playing contact sports If they played say gridiron or rugby, they would be like the bowling ball and normal people would be like bowling pins. ### Footprints in sand They would leave much deeper impressions is sand (IIRC the depths is proportional to the square root of the weight of the person - citation needed) ### Martial arts Especially sports like Judo - attempting to throw someone of twice the mass as you expect to the floor wouldn't work so well ### Anywhere you are weighed When flying in commerial light aircraft (less than about 20 passengers), they weigh you beforehand so they can distribute passengers mass evenly in the small cabin to provide safer flying Jockeys, boxers, etc are also weighed [Answer] They will have significant problems walking on non-solid grounds. Since their feet sizes are the same, they will be applying twice as much pressure per foot than a normal person. If they walk on soft ground, they will sink much further in than the next guy of the same size. Assisting them out of the hole will also reveal their extra weight. [Answer] To the other excellent answers I would add that there are a number of areas where the difference in inertia would be apparent. Any sport that involves sudden stops and starts like tennis or baseball would be affected. More dense people would slide farther. (There's a whole science of mastering sliding on clay or grass courts.) Dense children would be at a disadvantage in games like tag. I don't know about the climate in your world, but if they do things like sledding, ice skating or skiing I think the difference would be noticeable. Their greater strength would be apparent in tasks that don't involve moving around much of their body weight. If I understand correctly, their legs would be strong enough to jump about as high as a normal person. That means that their kicking power would be much greater. If they can do chin-ups as well as a normal person, they would be great at arm-wrestling. Magicians would probably be very picky about footwear. Unless their feet were magically tough, they would be more prone to foot problems due to twice the weight being spread out over the same area. Sitting on a hard bench would be twice as uncomfortable. Falling would hurt twice as much. [Answer] One slightly unfortunate impact would be on social activity. * **Raves/dances** - a bunch of these people dancing or jumping (social or to escape something) on the floor above you.... Crunch? * **Sex** - uh oh! Those forceful passionate quickies will have to go. They'll probably have enough inertia/momentum to break shower panels/tiles, destroy car suspension, crack thin dividing walls between hotel/motel rooms, and break beds. They'll have to be gentle and languid! * **Running** - you run, you tread on a plank or paving slab, and it has to withstand twice the impact force. Crack! * **Scuba** - requires strict control of weight neutrality using belts around the waist. * **Lifts/elevators/escalators/hot air balloons** - have weight limits. Oops! [Answer] **Alcohol Tolerance** A dense person has more tolerance for ethanol and will take more booze to get drunk. For a real-world example consider Andre the Giant. [![http://assets.atlasobscura.com/article_images/lg/22421/image.jpg](https://i.stack.imgur.com/GlQW1.jpg)](https://i.stack.imgur.com/GlQW1.jpg) > > It has been estimated that Andre the Giant drank 7000 calories worth of booze every day. That's about 46 beers a day. > > > Andre the Giant once admitted once on Letterman to having consumed 119 beers in a single sitting and passed out in a hotel hallway, and that wasn't even his record. > > > from <https://www.stuff.co.nz/entertainment/celebrities/82494695/> Admittedly he was physically big as well as muscular, so the quantity of fluid vs the potency of the alcohol content could be a factor. That is, fitting a lot of beer inside the torso could be a challenge so they'd prefer higher-proof spirits. [Answer] Just another addition: **Put them into / onto any vehicle such as a car or a motorized bike that has suspensions** In 'X-Men Origins', Wolverine, now with a freshly adamantized skeleton, gives himself away by just sitting on the motorbike and pressing it all the way down due to his unusual weight. [Answer] If they are a secret society, then definitely you will not know to look for such signs to recognize them. As well they likely use magic to conceal. Additionally imagine in a technocrat society nobody would believe any strange signs. Most people would rather think they are going crazy than thinking the other person is a magician. There was an old movie where a robotic young man/boy went to college and there were all sorts of funny moments when others hit him, the bed broke, etc. I don't remember the name of the movie but you can search for it. Update: I think movie was "Still Not Quite Human" ]
[Question] [ In order to define the best vehicle these inputs have to be taken into account: * The zombies are the classical ones, "the walking dead" ones are a perfect example (definitely killed only by headshot, attracted by noise, etc...). * We are in year 2018. Population: 2% alive, 18% definitely dead, 80% zombie. * The vehicle-proposing person must convince a party of 8-10 people. * The party is heterogeneous, one or two people are capable to perform some minor mechanical/electrical intervention on a vehicle, for instance they can add metal spikes, fuel tanks, firing loopholes, etc. They can't change the engine with a more powerful one or replace wheels with tracks. * Other specific, yet not really special skills, could be taken into account, for instance: one person could be really good at cutting and sewing, whether to use it to create nice curtains or a vehicle ghillie suit is up to your answer. * The party could also use other vehicles for scouting or scavenging, like a motorbike and/or a pick-up, but the main vehicle must be able to carry safely the whole party (but maybe not comfortably, it's not necessary to have one seat per person). * The party should travel to at least 5-6 different cities, 400 km far from each other on average, then they should find a final generic safe place. (400 km considering detours and menace escapes, see below) * In the party there's a very intelligent person (which should also be the one proposing the vehicle strategy and path), therefore feel free to suggest nice tricks, but he's a regular guy without specific high level skills. For example: he could find a clever way to enter a building, but he can't pilot a bomber or hack a bank's safety vault. * The party has some limited supply, and a relatively safe place for 7 days, therefore they have some time to organize the travel. They also have an initial mobility range of 20 km to find the final vehicle, and the 7 days can/should be spent also to modify the vehicle. * They live near a center-Europe big town, 30-50K people, even if most part of the city supplies have already been scavenged by other groups, it is possible to find fuel, food and tools with some research. The research is time expensive, therefore if the vehicle is easy to find and it doesn't need modifications they can use the 7 days supplies to start the travel immediately with some stock. Even though I prefer to have a customized vehicle. * I'd rather choose an European city instead of a North American one, because I don't like to have a lot of fire weapons involved in this travel. Of course hunting rifles and some pistols could be considered common weapons, but heavy machineguns are incredibly rare and RPGs/grenades are out of the discussion. * The vehicle should therefore withstand some low caliber shots, but it doesn't need to be a military armored vehicle. * Is also difficult to obtain any military grade gear because military bases are some of the most infested zone (emergency sirens attracted the zombies - they were the first choice shelter, but they eventually collapsed) or they have been reclaimed by huge groups of raiders. * The party should expect (obviously) zombies, blocked roads (mostly because of abandoned cars), and raider scouts attacks (3-4 people, armed but without big guns). Because of the surrounding zombies and the raiders' reinforcements, having to repair the vehicle for more than 1h have to be considered as game over. * The vehicle's speed is not really important except for the fact that a slower vehicle must carry more essential goods, and the faster ones are preferable because of flee chances. It is also valid the concept that a slower vehicle, yet capable to overcome most road obstacles, is actually a "faster" one with respect to a supercar that needs to take several dozens kilometers detours. * Flying could be theoretically considered, but it seems to be really difficult to find the right fuel, the noise will attract a lot of unwanted attentions from both live people and undead, once departed there are no chances to go back (noise->zombie), the destination airfield could be impracticable, and especially there are no trained pilots in the party (this limit could be bypassed, but the other cons must remain and therefore it's hard to justify a flying vehicle). * Railways could be an answer, but proper trains can't: every train except for few really old ones have electrical engines, and the diesel ones are not easy to be used by a common untrained person. Moreover, since at least any station is likely to have some trains on the nearby railway, the vehicle must be at least capable of both road/railway or to remove the blocking trains (also derailing the wagons and make them overturn could be an acceptable choice, but it's a long and noisy process). **EDIT, info from the comments:** - The food is rarer than the fuel. The party, considering some distractions (zombies and raiders), can gather 30-40 litres per day using 4-5 people. The food is rarer, the most canned food is already consumed and the people now need to hunt, gather edible vegetables or fish. There's no overall lack of food, the wildlife somehow grew in large numbers when humans stopped their activities, the issue is to collect that food. Hunting is time expensive and food preservation is limited. Moreover the "food" is usually outside the cities, while fuel and gears are way more common in the cities. Please describe a vehicle that fulfill the inputs, its most useful modifications, what to carry as essential goods and emergency supply and especially detail the reasons. If you think you have the perfect vehicle, even in case some conditions are bypassed, please still answer. Obviously the more conditions are removed, the less the answer will be interesting. **Bonus**: Travelling on water can't be an answer to reach the safe place (it's far from the sea), but detours on water are appreciated to reduce risks and let the party rest a little. Let's say that a couple of cities are near the sea, therefore if the vehicle could be easily carried by a small vessel it would be better. For instance, a small van has way more chance to be carried than a "Mad Max style" war wagon. **Malus**: I'm NOT ASKING for a zombie killer vehicle: even if it could kill several zombies, its main purpose is to carry 10 people for a long range trip. If you think that is safer and faster just to kill everyone in the path (zombies and raiders) by driving a huge beast on the vehicle then you have to justify it. --- **Edit**: my question is related to this one [What kind of land transportation can be used for plowing through hordes of zombies?](https://worldbuilding.stackexchange.com/questions/54552/what-kind-of-land-transportation-can-be-used-for-plowing-through-hordes-of-zombi) because we are talking about zombie apocalypse, but it's a totally different approach: i highlighted as malus a zombie-smasher veichle. Even though is admitted to propose a zombie-killer vehicle, the main goal is to move the party safely through EU, not to destroy a Z horde. [Answer] # Railway Maintenance Vehicle [![enter image description here](https://i.stack.imgur.com/FdPLy.jpg)](https://i.stack.imgur.com/FdPLy.jpg) ### Ride on the tracks. They go everywhere and will be mostly clear. ### Obstruction on the tracks? Hop off and drive around it. ### Build a living space and storage space in the large flatbed area. ### Extra bonus: Crane Arm. Use it to clear paths, load supplies and fight zombies. ### Most models change modes with just the push of a button! You don't even have to get out. [![enter image description here](https://i.stack.imgur.com/mcgOB.jpg)](https://i.stack.imgur.com/mcgOB.jpg) The most important roads for getting out of the infection zone are going to be the ones that are most impassable. Everyone will have tried to escape the oncoming horde by car, then abandoned their vehicle in the road when they got stuck in traffic. Other road-based suggestions like the Firetruck or Semi will get abandoned by your party too when they see the endless sea of cars they would have to push out of the way. Off-roading the whole way is slow, risky, and unreliable. ### But the rail system will let you cruise across the quiet countryside, away from cities and noise and danger: [![enter image description here](https://i.stack.imgur.com/yzuMo.jpg)](https://i.stack.imgur.com/yzuMo.jpg) When you want to hop-off the rails, the little access-roads and dirt roads won't be clogged, since they weren't evacuation routes. If a road is large enough to be clogged by the evacuation, it's probably also large enough that the train tracks go over or under it. Your only trouble will be if the tracks have a level crossing with a clogged road. You'll need to find a way through. But with road wheels, train wheels, a powerful engine, and a crane, nothing can really stop you. The deck where you'd usually collect the fallen trees or store utility poles provides plenty of space for building an armored living/storage enclosure. I recommend cutting a hole through to the cab so you can switch drivers and put armor over the cab doors. I recommend putting the door at the back, where it can be defended by the crane-arm. [![enter image description here](https://i.stack.imgur.com/hwJWJ.jpg)](https://i.stack.imgur.com/hwJWJ.jpg) Whatever railway vehicle you find, the railway maintenance package will be built onto a truck model also used in heavy-duty tow-trucks, medium flatbeds, snow plows, and more. So it will be possible to find replacement parts. It will run on standard diesel and have large gas tanks just like the Tractor-trailer answer. They are essential fleet vehicles because they might need to help clear the tracks to restore rail service after an incident, so they are very well maintained just like the Firetruck. [Some even are firetrucks.](http://www.railwaygazette.com/uploads/pics/tn_be-diabolo_fire_engine.jpg) It's not hard to drive like the giant dump truck or an actual locomotive. You lower the train wheels with a switch on the dash, let go of the steering wheel, and use the normal gas/brake pedals. (often, the locomotion in track-mode comes from the tires simply resting on the top of the tracks.) I don't know if anyone has even thought to measure the fuel-economy these vehicles get while driving on the rails, but I can't see why it would be worse than on the roads. It might even be better. They can travel at the same speeds as the trains, and they are heavy-duty enough to carry the weight of all your stuff and their improvised armor while still driving aggressively. **Speaking of aggression:** [![](https://i.stack.imgur.com/NhEJt.jpg)](https://i.stack.imgur.com/NhEJt.jpg) "The articulated buzz-saw arm with enclosed cab package is perfect for the modern zombie hunter who prefers an elegant, superior, refined solution, yet still has a taste for the old classics." People are saying it will be hard to find one of these. [I went looking for one this morning and found one in no time.](https://i.stack.imgur.com/YdWLn.jpg) It was at the first terminal rail depot I checked, parked in the bus loop. I found another one parked on the street nearby: [![enter image description here](https://i.stack.imgur.com/Gem4J.jpg)](https://i.stack.imgur.com/Gem4J.jpg) These were out on duty. I didn't even have to check the obvious place, which would be the central rail maintenance facility where they are stored. They store a [whole fleet](https://www.elektro-thermit.de/fileadmin/et/user_upload/Pics/Produkte/GOL-2017-06_SRS-Portfolio2_Standrad-Zweiwegefahrzeuge.jpg) of these vehicles there. They're called [road-rail vehicles.](https://en.wikipedia.org/wiki/Road%E2%80%93rail_vehicle) ## More info on what using this would be like: These road-rail trucks are designed to change modes at a level crossing or other place where the pavement is level with the top of the tracks: [![enter image description here](https://i.stack.imgur.com/ZkFSz.jpg)](https://i.stack.imgur.com/ZkFSz.jpg) That should be easy, and with a little practice could be done in mere moments without people getting out, assuming you're on a wide enough crossing. At a narrower crossing it's possible, just a lot more fiddly work and possibly using wood blocks and wedges ramps to get the wheels to climb up onto the rails (figure 20 minutes). This sort of work isn't about brute force, it's a chess game (like a much harder version of "parallel parking"). The rails are as tall as a curb, and you've got to be lined up with them a particular way. Hopping off the rails *not at a crossing* will be quite the puzzle, you could find your fronts outside both rails and your rears half in half out, or even stuck between your duallys. Lots more work with the blocks and wedges to get the wheels to climb out in a useful way to get you off the track (figure 30-40 minutes). Getting **on** the track not at a crossing would be **much** harder (for noobs, 1-2 hours with lots of frustrating mistakes). And if you *ever* forget to pick your blocks and wedges back up, you're in trouble next time, and must go on a scavenger hunt for suitable blocking. A railroad tie weighs 150-250 pounds. But if you want, you could have your characters discover, after they leave the first rail-yard, that it isn't a breeze, and have a tense moment where they are pushing the gas pedal to the floor trying to get a stuck wheel to hop over a rail. At a larger crossing, the trouble will be getting the truck situated correctly so that the train wheels hit the rails when they are lowered. You start with the rears (since you can only steer the front) - this goes a lot faster if the truck has a backup camera, and some clever foreman has Sharpie'd on the screen where the rails need to be. Otherwise, for a newbie, this will be fussy and probably require someone to get out and help you line it up. Still, setting on would easily fit within your "no more than 1 hour repair" window. But keep in mind if you're driving in truck mode when attacked, unless you find a level crossing, jumping back onto regular tracks is gonna be too slow. You'll have to flee in truck mode till you find a level crossing or lose your pursuers. If you've got a character who knows as much about these vehicles as I do (and I don't work for a railroad or anything I just like trains and read about them sometimes) then they'll know that the best plan is to only change modes at level crossings. If you leave the rails without knowing where the nearest level crossing is, there's a moderate chance you'll be stuck in truck mode for a while. It might be a good story mechanic to have your characters pick a truck that because of its size and particular alignment of tire-spacing, isn't able to hop onto the tracks except at level crossings. Then when they decide to get off the tracks, you've got that tense plot element of being stuck in truck mode until you find that next crossing. When you come to a fork in the tracks, it will be 'switched' to send trains one direction or another. If you don't want to go the way it is currently set, you'll have to stop and have someone get out and change it. Most switches are remotely controlled, but that system will be offline. Someone could get out and switch it manually, but that might require a particular tool or key or both, get those off train crew zombies or find them in a rail depot). So if you are fleeing down the tracks, you might come to a switch and just have to go whichever way it's currently set. Though you might be able to hop off at a crossing, drive around the switch and hop on to the line you want. The trucks back up very easily, but possibly not quickly, as the reverse gears are pretty slow. That's a vulnerable point; if you arrive at a blocked point on the track, you may not be able to reverse fast enough to lose the zombies. The truck probably has a transponder for PTCS/ATC/TPS, which is a radio/GPS based anticollision system - it advertises your location to other trains and control points (bad) but also prevents fast trains from plowing into you (good). Your heroes may be able to figure out this transponder exists, and if they do, shouldn't have too much trouble pulling the power cord out of it. [Answer] What about a boat? (zombies can't swim right?) Europe has a pretty good river system and will get you to pretty much every big city. The two mechanics will have to deal with operating locks along the way, there's always a manual override. You can go with a group of two or three motor yachts or one large river cruise ship or converted freighter. Boats are a reasonably fuel efficient way of travel. They already have large diesel tanks (some motor yachts already carry 750 to 1500 liters of diesel). Don't need a lot of alteration, already equipped with everything you need for your survival (water tanks, kitchen, beds, solar power, etc.). Perhaps you can get down to the sea and continue traveling along the coasts using sailing yachts. When you do get to the coast, go looking for a yacht with a fresh water maker ;) . Here is an overview of rivers and channels accessible by inland freighters. You can often travel some ways further up river using smaller vessels (research required). [![Detailed overview of rivers and channels accessible by large inland freighters around the netherlands.](https://i.stack.imgur.com/NpCaf.jpg)](https://i.stack.imgur.com/NpCaf.jpg) [![Overview of all rivers and channels accessible by inland freighters.](https://i.stack.imgur.com/OB2gW.jpg)](https://i.stack.imgur.com/OB2gW.jpg) [Answer] What about bicycles? They're quiet, they don't require finding fuel, they're maneuverable, they're easy to repair even for laymen, they can be used in multiple different types of terrain, and they're fast enough to outrun a traditional zombie hoard. [Answer] I suggest a [heavy rescue vehicle](https://en.wikipedia.org/wiki/Heavy_rescue_vehicle). (a type of specialty firefighting or emergency medical services apparatus, primarily designed to provide the specialized equipment necessary for technical rescue situations such as traffic collisions requiring vehicle extrication, building collapses, confined space rescue, rope rescues and swiftwater rescues. They carry an array of special equipment such as the Jaws of life, wooden cribbing, generators, winches, hi-lift jacks, cranes, cutting torches, circular saws and other forms of heavy equipment unavailable on standard trucks) It's basically a Jack of all trades of whatever hazard you're gonna find on a road. And as an emergency vehicle, it should be well-maintained. It may be a bit small, as they do not seem to carry more than half a dozen people. It also should be quite easy to find, looking in fire stations, but that means it's probably already been looted. [Answer] **Go big:** find a [Haul truck](https://en.wikipedia.org/wiki/Haul_truck) from a quarry or mine. [![A big haul truck](https://i.stack.imgur.com/lT6pN.png)](https://i.stack.imgur.com/lT6pN.png) ([Image source](https://en.wikipedia.org/wiki/File:CamionFermont.png)) Even just the size will make it hard for the zombies to climb. You'd probably want to weld on some additional stoppers. The height makes it easy to spot and shoot any approaching zombies from far away. The size means that you can take pretty much anything you need with you, any amount of water and food and other supplies you can find. The truck will also go off-road just fine, the big wheels will cross ditches without any problem. However, prepare to spend quite some time finding fuel sources - these trucks usually have about 5000 liter tanks and eat about 1000 liters per 100 km, travelling at about 60 km/hour. Being diesel engines, you can run them on heating oil or even food oils also. [Answer] A seaplane can fly 10 people plus supplies 1000km before refueling. Takeoffs are loud but relatively safe as any attracted zombies will slip below the waterline. Landings are more dangerous but relatively quiet if you cut engines at high altitude. The downside is needing to row to shore. [Answer] A Toyota pickup truck. They are reliable and dead simple to repair. They can carry a lot of people. They can operate off road. They are easy to acquire. They require no special skills to operate. For the past 30 years they have been used in civil wars and insurgencies in third world countries. <https://en.wikipedia.org/wiki/Toyota_Hilux#Use_by_militant_groups> <https://en.wikipedia.org/wiki/Toyota_War> [Answer] Many models of fire truck will seat 6-8 comfortably. 10 would be a squeeze, but it's doable considering that the seats are designed with men wearing fire gear in mind. These specialist vehicles have the added advantages of very large water and fuel tanks. While your mpg/mpk won't be great it's still comparable to most large trucks, and lorries, somewhere between 3-8 mpg depending on load. They also come equipped with most of the things a party is going to need to survive. Lots of water, medical supplies, fuel, and a few solid axes; add food and your very basic needs are met. These vehicles are also likely to be equipped with some very nice speciality gear. Towing gear, wrenches, pneumatic cutters and spreaders, hoists, powered lifts/extension ladders, and let's not forget the the water pumps. A fire hose is a formidable weapon; if focused properly you can easily push back a zombie horde. (See riot control applications of fire hoses). Keep in mind that many modern trucks are capable of both pumping out and pulling in, refilling shouldn't be too problematic. Fire retardant clothing, rebreathers, thermal imaging, and other fire specific gear could also come in handy. You'll also have much more than a standard first aid kit. Not quite as nice as an ambulance, but the next best thing. IV bags, defibrillator, intubation kit, pretty useful stuff post-apocalypse. Then again... If you're raiding the firehouse, you could take an ambulance as well. Many stations will house both. Plenty of storage space, both in compartments and on top, more than enough to meet the need. Your standard firetrucks are very sturdy vehicles, many come with a roughly two foot wide bumpers for pushing and ramming, run flat tires, etc. Forestry service models offer additional protection in the form of much beefier designs including exterior roll cages that are designed to take the force of falling trees. Additional armour may be required to stop bullets, but that's true of most any vehicle beyond military hardware. Another huge advantage is that firetrucks are typically maintained exceptionally well. When in service these trucks never miss an oil change or brake pad swap. When you find one, you can count on it being in pretty good condition. Lastly these vehicles aren't incredibly rare. Much more likely to find a firetruck than, let's say, an armoured bank car. Most any city will have several, and post apocalypse they're likely to be a fairly common sight. [Answer] I'm sure it's not the most optimal answer, but what might be amusing is an amphibious bus such as those used in [Duck Tours](https://en.wikipedia.org/wiki/Duck_tour). Advantages: * Amphibious (obviously). Would be able to cross calm bodies of water. * Roomy. Should be able to easily carry 8-10 passengers plus supplies. * High off the ground. Zombies would have trouble getting in. * Tough. If the vehicle is military or military surplus, it would presumably be fairly durable. * Openness. The possible lack of windows or walls in the passenger area would be a vulnerability, but would also offer numerous escape routes in an emergency. [Answer] There is no conventional vehicle that will satisfy your desires, because in a situation where 98% of people are dead, the roads are not navigatable. Period. If everyone died at the same time, they’ll be clogged with crashed cars: if this was a more gradual apocalypse, they’re clogged with the cars of desperate, now deceased, evacuees. There’s 300 million cars in Europe. In an apocalypse, most of them will be stopped in the least convenient places possible. In some places, you might be able to drive around them, but the places that will be most clogged are bridges and tunnels where it won’t be an option. You’re also screwed on most one-lane roads, which, especially in Europe, are everywhere, usually with precipitous drops to the right and sheer walls to the left. Want to go off-roading? Good luck: allied tanks, with sappers to back them up, had a nightmare of a time going through the hedgerows and farms of France, and that’s hardly a unique trait of France in comparison to countries in the rest of Europe. What you want is not a group transportation method, but a bunch of light, flexible options, which are used per-individual. I recommend folding bicycles and inflatable kayaks/rafts. Parts are easy to get, they require no fuel, they’re almost completely silent, a literal child can learn almost everything you need to repair one in a pinch. The rafts will get you wherever the bikes can’t. The additional benefit here is that there’s no one point of failure in your group: losing your mechanic doesn’t screw you when something in your engine goes blooey. [Answer] Well, 8-10 people means a large vehicle. It needs to be relatively durable, have at least a decent cargo capacity, and have a strong engine. Looks like a cargo Lorry to me. Probably with a extended cab to fit more people in. <https://www.mrmoneymustache.com/wp-content/uploads/2015/04/wm-truck.jpg> (Pic from google, shows a cargo Lorry with an extended cab and standard 40ft trailer) If you are worried about strength of the vehicle.... 148,000 lb (67,000 kg) max weight it can carry. (this size is uncommon, but achievable) Modifications: * Bigger Fuel Tanks. This lets you skip towns that might have too many zombies without having to worry too much about how much fuel you have left. * Armor. I'll assume cartridges are maxed out around the 30-06 rifle for common use. (please correct me if I'm wrong.) So a solid inch of steel all around the walls of the trailer, and at least 1inch around the cab. Maybe bullet-resistant windows as well, or steel trapdoors on the windows. * In the armor, small trapdoors on the wall to allow rifles to poke out. So you can reply to raiders without having to get out of the trailer. * On the roof itself, have a hatch leading into the trailer. This is for people to shoot out of the top and also for emergency escape. Folding armor plates (trapdoors that lead to nowhere, the door itself functioning as armor) should provide enough cover to be useful. * A connection between the cab and trailer. Like a *Articulated bus*, should not only be feasible, but recommended. Sadly, armor would be light to non-existent here, so install good doors to compensate. * On the outside, a small plow, wheel covers (to prevent bandits from easily shooting out wheels), and some lights to shine in entryways. Also, more mirrors in order for inhabitants to see outside bit. * On the inside, some storage, rifle/shotgun rack, bunk beds or hammocks, as well as maybe a workbench. Make sure whatever you put in there is secured and if possible bolted down. Maybe take/make some sort of folding plywood wall along with chicken wire in order to make quick walls while scavenging or setting up a base. * Paint: Do not color it black, color it a dark blue. It's better for nighttime camouflage. * Backups: since things can go wrong, you need backups. In this base, I recommend taking a couple of bikes for land travel, and a couple inflatable kayaks for water travel. Weaknesses: * Military gear. Please don't use this to raid military bases. It can be disabled by landmines, shot up by .50 cal quite easily, and does not fare well against explosives. * Rough terrain. This is not going to fit through a forest or anywhere not relatively flat. * Attacks from above. The roof, in order to save weight and structural integrity, is unarmored (or maybe lightly armored). In either case, someone in a sniper's nest can do serious damage. Constructing a counter-tower on the trailer itself is bad due to stability issues as well as having to go under bridges tends to not go well with tall structures attached. Pros * Mini-base. Who needs to make shelter when it is already there? Just park and set up minor defenses! * Combat effectiveness. While not a military vehicle, it can take a beating from hunting rifles and shotguns. * Plow. If you have enough momentum and a large plow, you can shove vehicles out of the way. (Mythbusters did something like that) * Power. It would be very easy to mount a small generator to the cab or inside the trailer (if inside, include venting system). This allows indoor lights as well as a place to recharge electrical devices. * A large cab model can have a toilet installed, so you do not need to exit in order to relieve yourself. * End of journey. You already have all you need for a house. Just park and build around the truck to get a good quality home! [Answer] I am a pilot so I would chose a light twin, its fast, its above all the issues, and you can get in and out of places quickly and blocked roads are not really an issue. There are some myths in your statement that are worth dispelling which makes it a far more realistic choice. > > Flying could be teorethically considered, but it seems to be really > difficult to find the right fuel > > > This is not really true, especially if you are running on the assumption there is fuel for a car or truck in question the shelf life of auto gas is no better than Jet-A or 100LL. As a matter of fact the requirements for aircraft fuel storage, filtration and the issues once encountered with fuel system clogging has lead to extremely high quality storage for aviation fuel (far better than auto fuel). In the light twin game you have two options piston planes (running 100LL) or Jet/Turbo Prop (running Jet-A). Jet-A is plenty abundant at pretty much all airports and tends to [store pretty well for a long time.](https://generalaviationnews.com/2011/02/06/how-long-can-jet-a-be-stored/) Even a small amount scavenged from a sitting airliner is enough to top off a light twin. Generally speaking airports tend to have [quite a bit of fuel on hand](https://www.tanknewsinternational.com/wp-content/uploads/2017/05/ST-McCarren-Airport-.jpg). Piston planes [typically run 100LL (100 octane with lead added) also known as AvGas](https://en.wikipedia.org/wiki/Avgas). 100LL is actually one of the more "rare" fuels out there since its only application is for light piston aircraft these days its just not made in the quantity it once was. That being said plenty of aircraft can easily be [modified to run auto-fuel or "MoGas" and there are lots flying out there that do.](http://www.autofuelstc.com/piper_airplanes.phtml) As a matter of fact many of the common aircraft engines out there from [the big makers were originally certified to run on 87 octane.](https://www.avweb.com/news/maint/187232-1.html) I would not advise climbing up to the service celling but it will get you off the ground, and move you a few hundred Kilometers. > > the noise will attract a lot of > unwanted attentions from both live people and undead, once departed > there are no chances to go back (noise->zombie) > > > This I understand, and shy of a mechanical failure which you can mitigate with extensive pre flight checks you would not be looking to go back anyway. A diesel truck may very well loud and draw attention to you just as much as an aircraft but in one your off the ground in less than 30 seconds. > > the destination airfield could be impracticable, > > > Who says anything about landing on an airfield. While runways are nice [airplanes land on grass all the time](https://www.youtube.com/watch?v=dvG-xjOYSSI). Most light twins can be landed in under 4000 ft. (some in even far less). > > and especially there are no trained > pilots in the party (this limit could be bypassed, but the other cons > must remain and therefore it's hard to justify a flying vehicle). > > > As you say, this can be bypassed so lets assume there is someone in the group with some flight experience. As for withstanding gunfire [ill direct you to this question for more info on that.](https://aviation.stackexchange.com/questions/13600/can-a-handgun-shot-take-down-a-commercial-airliner/13840#13840) And to answer the question directly, id try and find a nice [de Havilland Canada DHC-6 Twin Otter](https://en.wikipedia.org/wiki/De_Havilland_Canada_DHC-6_Twin_Otter), high wing making it easier to land in a field, fixed tricycle gear so you don't need to worry about retract issues, plenty of room to fit everyone, and turbine powered so I can scavenge some Jet-A. Other solid options are a [Beech King Air](https://en.wikipedia.org/wiki/Beechcraft_King_Air) or a [Mitsubishi MU-2](https://en.wikipedia.org/wiki/Mitsubishi_MU-2) or even a [Cessna Caravan](https://en.wikipedia.org/wiki/Cessna_208_Caravan) if you were confident in a single post apocalypse PT-6A. [Answer] **How about three hot air balloons?** [![enter image description here](https://i.stack.imgur.com/WsGrl.jpg)](https://i.stack.imgur.com/WsGrl.jpg) one for 3 persons, the other for 3 more persons, and the third for 4 persons. they can be **launched from any large free field**. they are a **safe place** (if they fly high enough), and have **enough capacity for food and fuel** for the whole journey, too. they launch and fly **silent** (if using the "right" fuel) (**each could carry 5 persons + regular fuel** ([technical data of standard hot air balloon](https://www.xn--ballonfahrten-allgu-bodensee-nnc.de/index.php?view=article&catid=31:allgemein&id=77:technische-daten-eines-heissluftballons&option=com_content&Itemid=101)), but the fuel they find may be less efficient so they would need more fuel and they need food and weapons as well, plus, they should carry some rope and an ancor, too (will explain later) ) The heroes may **find enough balloons**, if they don't **the one good at cutting and sewing** could **craft** them using **any cloth** that is **light enough** ( and it should **not** be to **leaky**, too ). the balloon **must not be leakproof**,leaks will only result in less fuel efficiency. (this is why **airships are a bad solution.** just thinking about loosing helium and therefore height due to a leak loudly crashing into zombie town! ouch \*:) ) they can **use anything that burns well for fuel** (**fossile fuels** or even **fat**). even **zombies fat**. **fat** has **only** about **twenty percent less energy density** than **propane** (calorific value) plus you **do not need heavy gas bottles** plus fat can be **easily synthesized**. [![enter image description here](https://i.stack.imgur.com/vjXiL.jpg)](https://i.stack.imgur.com/vjXiL.jpg) if the heroes don't find enough fat, or want some easy-to-burn fuel, they could use **ethanol**. they could make ethanol out of **zombies**, **raiders**, and any other **trash** using **fermentation** and **destillation**! they would have to carry **more fuel** (mass) with them if they used ethanol instead of oil since **ethanol** has about **42 percent less energy density than propane** (calorific value) while oil only has about twenty percent less energy density than propane. (calorific value) [![enter image description here](https://i.stack.imgur.com/CA8vr.jpg)](https://i.stack.imgur.com/CA8vr.jpg) but **ethanol** can be **burned easier** than fat. [![enter image description here](https://i.stack.imgur.com/AoUTJ.jpg)](https://i.stack.imgur.com/AoUTJ.jpg) **burning the fuel** is quite easy, the heroes just put **some cloth** in an **open barrel filled with fuel** and **lit it up**! the heroes have to find or build some **fan** to **start filling the balloon** with air, but even building a fan is easy, they just take **any electric motor** (or even a diesel one if theere is no electricity (out of a vehicle) ) and **connect a screw-propeller** (maybe diy) to it. maybe the heroes use **fat and ethanol as fuel**, using the **ethanol for lift offs only** (since it **burns faster**) and the fat for the rest of the journey. if they find out that they **cannot lift off** because their way of **burning the fuel is not fast enough**, they just have to get **more balloons**, so **each takes less payload**, and **try again**. [![enter image description here](https://i.stack.imgur.com/4W8fa.jpg)](https://i.stack.imgur.com/4W8fa.jpg) btw, they could also **throw such molotov coctails down when attacked**. Also, their **usual fuel, gas bottles**, can be found at many **european gas stations**. The heroes **wait for the right time to lift off**. (when the wind goes into the right direction) if the **wind changes unexpectedly**, **they go down** (do not land!!!), **throw the ancor down**, and **hover** until the wind changes again. (while hovering they need **far less fuel**, since the air around is dense and the heavy ancor is down.) **if attacked** while hovering near the ground, they may **lift off again**, or **destroy the attacker** with **molotov coctails**. one could **destroy entire small armies** with such an **air attack**. [policemen on fire due to one single molotov coktail in paris](http://time.com/4764079/policeman-on-fire-paris-may-day/) [![enter image description here](https://i.stack.imgur.com/VWCQ1.jpg)](https://i.stack.imgur.com/VWCQ1.jpg) [Answer] ## The Antonov-2 *You did say central Europe*. [![enter image description here](https://i.stack.imgur.com/ja8HR.jpg)](https://i.stack.imgur.com/ja8HR.jpg) This is a [BEAST](https://all-things-aviation.com/aircraft-accidents/robin-dr400-wake-turbulence-accident/) of a biplane. Designed post-WWII, [this thing](http://www.classicwings-bavaria.com/html/biplane.php) is designed to carry big heavy loads and land pretty much on a driveway. It seats 12 and its nominal use is large scale cropdusting. Useful load is 4700 lbs. But what makes it amazing is its short-field performance. It's essentially a fixed-wing autogiro. Stall speed is a mere 26kts (30mph) - that is stupid crazy low even for a SuperSTOL. That means you could land in a driveway or even VTOL into a stiff headwind like a Harrier) -- though you'd want a bit of runway for that max-weight takeoff. It's powered by a 1000 horsepower Wright R-1820 (or Soviet equivalent). Range is 525 miles on 1200 litres (300gal) fuel -- so you'd need to turn it into a "flying gas can" or make an intermediate stop for fuel. Cruise speed is 120 statute mph. This was introduced in the late 1940s with over 18,000 built. There's nothing quite like it; it's a bush plane *extraordinaire*. [Answer] For me the main consideration is the group size, anything smaller than some kind of converted bus is going to be impractical for 8-10 people on a reasonably long trip, especially since they'll want to shelter in the vehicle for sleep, probably more often than not. A large bus will give you a good amount of space in which to do conversion work like expanded fuel tanks, food and water stores etc... so that's a plus as well. They tend to be durable and relatively mechanically simple so as to reduce maintenance costs as well which is useful in a wasteland environment. I would council against using any single vehicle for any trip in an apocalyptic setting, rather you need at least two vehicles each individually capable of completely the journey with everything you need to take and everyone on board, you should be planning for the loss of at least one vehicle in such a hostile situation. [Answer] A decently fueled [diesel](https://worldbuilding.stackexchange.com/a/81565/46957) semi truck with a trailer to store your stuff could get you 1000km on a single tank of gas. As can be seen on [this Truckers Report forum](https://www.thetruckersreport.com/truckingindustryforum/threads/mpg-of-your-truck-full-and-empty.266087/)\* question, fuel economy for a fully loaded truck is roughly 7 miles per gallon, or about 3 kilometers per litre. And [this question](https://www.thetruckersreport.com/truckingindustryforum/threads/fuel-tank-size.113682/) shows that capacity ranges from 50 gallons on the low end to 300 gallons on the high end, or about 189-1135 litres. So, the average semi truck could carry enough fuel for a 600-3000km trip. Combine this with sturdy wheels, powerful and reliable engine, ample storage space for people/food/water/fuel/knick knacks, and a rotating set of drivers [due to the built in cab bed](https://cdltrainingtoday.com/life-inside-a-semi-truck-sleeper/) means this truck is only gonna stop when you want it to. --- * Yes, it's some random forum and not at all scientific, but niche forums like that are usually reliable. [Answer] Luckily your requirements match quite well with some current thread-scenarios of asymmetrical conflicts. What the military has come up with are the so called [MRAP](https://en.wikipedia.org/wiki/MRAP). I´d suggest the German [ATF-Dingo](https://en.wikipedia.org/wiki/ATF_Dingo). You´d have to get the long version for 8 People or two of the small ones for 10. [![enter image description here](https://i.stack.imgur.com/ulajT.jpg)](https://i.stack.imgur.com/ulajT.jpg) (Source Wikipedia) [Answer] If this is going to be made into a movie, I'd go with a double-decker city bus. For the American (ticket-buying) audience, those are amusing and characteristically European (or really British). Fun to see on screen. I think a Harry Potter movie had a battle in one. Modifications that ordinary people could make would be to weld some sheet metal onto the bottom floor windows. If the bus has a back door, you could load the bottom floor aisle with barrels of explosives or other surprises to roll out the back at enemies during a high-speed pursuit. Weld some blades onto the hubcaps to cut down zombies on the road (like an old-time war chariot). You might weld something like a cowcatcher or plow on the front to knock down any zombies that block your way. Really, if your characters can get their hands on a welder, they can make some crude improvements fast. From the top floor of course you can position warriors with firearms. At quiet times they'll have a lookout stationed in the "crows nest" and this would be a good setting for conversations or the romantic sub-plot to play out, under the stars or whatever. In the eventual climactic battle, the surviving characters will set the bus, packed with explosives, to ram into the enemy base, and they can bail out from the top deck. Oscars, here we come. [Answer] Going for a single vehicle is a bad idea. If it breaks down or gets stuck, the whole group is in peril. Instead, consider 3 or 4 off-road capable SUV's, like Jeeps or Land Rovers, and wagon train it to your destination. * Common enough to find, and to find parts for * Everyone can drive them * Small enough to move around obstacles on the road like broken down cars * Maneuverable enough to handle situations like sloped road sides to get around blockages. * Big enough, though, to push through at least a small group of Z's * High enough ground clearance to handle being off road, or over partially obstructed roads * Good in areas that may be flooded * If one gets stuck or breaks down, the people in it can pile into the others, and in a true emergency, they can all fit in or on one (uncomfortably) * In a tactical situation, multiple vehicles can flank and maneuver in combat, and split up to make it difficult to be followed. Ideally, you might want to combine a couple of the answers here - multiple types of vehicles in one convoy. Some for scouting ahead, some for moving the bulk of people and supplies, some dirt bikes carried along for investigating narrow routes, hybrids for generating power at camp, etc. [Answer] You gave a list of reason as to why air travel might be an issue but what if I can give you an air travel method that would solve all those issues while still answering all of your requirements? I give you the [airship](https://en.wikipedia.org/wiki/Airship): * Exist in RL 2018 * [Zeppelin NT](https://en.wikipedia.org/wiki/Zeppelin_NT) can carry 12 passanger + 2 crew members meeting your party size requirements * Very low maintenance air vehicle heterogeneous party is all that's needed to maintain it for a single 1000km trip * 400km-1000km trips have been done in airships more then once * Multiple stops & takeoffs in a single trip are easily possible * The 7 days are more then what's needed to prep an airship for takeoff and no defensive modifications are needed as we all know zombies can't fly and the airship doesn't need to land until they reach the 1000km destination * There are airships in Europe (not as plentiful as planes but still there are some) * Low fuel usage - only fuel needed is to power the props for forward & directional trust, once inflated buoyancy takes care of lift. * **unlike stated in another answer modern airships can withstands a lot of damage**, their frame is made of different compartments so even if shot at and multiple compartments get bullet holes in them the rest remain intact and keep the ship afloat, also the most commonly used lifting gas, helium, is inert and therefore presents no fire risk. * There are civilian airships so no military gear needed (but there are also military and police airships BTW - they make great observation posts) * Fly over all the zombies, blocked roads & raider scouts (airship can fly far higher then most bullets can get at so after takeoff your safe from any attack short of military grade AA guns, rocket or other air vehicles) * They are slower then airplanes true but the Zeppelin NT example I gave above gave above has a cruising speed of 115 km/h, you can reach your destination in a single day flight so if you pack lunch you aren't even going to miss a single meal (and you can even eat while flying), cargo is a non issue as the same Zeppelin NT is built for 14 people and you only got 8 on board. * fuel is standard aviation airfuel for most types but in theory as airship engine are only used for maneuverability you can use normal fuel as a replacement in a pinch, there have been reported cases of aircrafts flying on normal fuel & as airships don't have a minimum speed to stay afloat there's no risk in having reduced efficiency. * They are a lot quieter then aircrafts. * No airfield is needed, any open space is a possible landing zone. * Are easier to fly then airplanes, if I was in a zombie apocalypse and had a blimp nearby I would rather try flying it then taking any land base method of transport, you also mentioned this is the only limit that can be bypassed in possibly having a trained pilot in the group. * Flies over water just as easy as it does over land. [Answer] When planning a long journey, start with a vehicle built for long haul travel and adapt to the other challenges, the journey is the toughest part here. So many solutions here are ideal for the zombie-apocalypse but lacking on the long-haul side of things. How about a long-haul Coach bus? They've got room for 50+ people in their main passenger configuration, but if you got one retrofitted for Band Tours then you'd have a lot more interior space to play with and more amenities for your smaller group, things like a minifridge/freezer, bar, bunks and so on. Most coaches have a chemical toilet, a hell of a lot of cargo space in the lower deck, and critically the passenger space is raised a good two meters off the ground. They also have hatches in the roof in case the vehicle flips on its side, so you could potentially build a fighting platform on top without too much trouble. They're built to travel long-distance, so good mileage is a given, they also usually run on diesel and fuel should be relatively commonplace and adaptable to other sources if necessary. With the band-tour buses, the windows are frequently blacked out to fend off the paparazzi, so you'd be able to have light inside the bus at night without being a beacon for any raiders/zombies that might be watching. Offroad travel is not going to work, but with some retrofitting you may be able to fit a large snowplow to the front of the bus and push aside any other vehicles on the road. [Answer] How about a crane vehicle like this one: <https://goo.gl/images/zUo9km> It's large, you can create some makeshift shelters alongside the crane, it's well capable of storage capacity (extra fuel and food) on the sides and you can potentially deal with things like trees across the road and other large multi-ton obstacles. Possibly you could drive with the crane slightly lifted while it carries a shelter underneath (chained to below so it doesnt move constantly). This would give a vantagepoint and protection from Zombies and mean only the drivers cab needs a lot of protection (and perhaps the crane-cab). I'm assuming that most people intend to live, so raiding is unlikely as it's a time-consuming, high risk and loud endeavor with high risks even if you succeed due to the zombies, and you dont know what kind of resistance you'll meet. Also with 90% of the populace killed trying to raid other people is a terrible idea as you'll find precious few people to actually raid. This means it requires little protection from bullets, and more in the way of speakers and antennae to communicate and trade with survivors. As a secondary idea I would go for velomobiles: <https://en.m.wikipedia.org/wiki/Velomobile> Velomobiles are bycicles/recumbent bikes that have a protective shell around it. A trained person can reach 90km/h on them, made easier with electric motors that draw 1/8th the energy of a fully electric car. Often they can carry 200kg of luggage or in this case supplies besides the driver, and in some cases they can carry a small cart behind it. The biggest problem with this is that it's not a single main vehicle. Perhaps these could be carried on a main vehicle like the crane to "shop" around the area you stoppes in. Otherwise these velomobiles are small, allowing them to maneuver through gaps, debris and parked cars. They are low and hard to keep track of when you take off things like visibility flags, perfect for avoiding zombies. And perhaps the most important: they are extremely silent. In a dead world like you describe a car engine could be heard for kilometers around, especially downwind. Almost soundless vehicles would be key in avoiding the zombie hoards. As a last advantage: with a dynamo or solar panels you can recharge your batteries, while fuel ages quickly and becomes useless. This means the velomobiles would be able to reach any city you want without fuelstops that have to be near zombie-populated area's (where any pumpstation would be located), and even if you run out you can keep pedalling and retain high velocities. Edit: for repairs, velomobiles require relatively little. Drag some of the compounds that together make the shells and you can repair holes. For all other repairs any bycicle kit will do and unpowered tools can be used to repair or replace parts of the frame when damaged. A pretty important feature when you cant just pop by a garage for repairs. [Answer] Rally Truck 2018 Dakar Rally Winner (Tatra) [![enter image description here](https://i.stack.imgur.com/0MkYl.jpg)](https://i.stack.imgur.com/0MkYl.jpg) 2018 Dakar Rally Second Place (Kamaz) [![enter image description here](https://i.stack.imgur.com/SHR8S.jpg)](https://i.stack.imgur.com/SHR8S.jpg) [Answer] Much depends of the rate of travel of a zombie, and how acute their hearing is. If you were is western North America (US or Canada) and not on the coast, I would say that your best mode of travel would be horse. I don't know the settlement pattern of Europe well enough. I think horses would work in Germany with aobut 30% forested and wild lands, and would NOT work in Belgium and Holland. Travel cross country to avoid concentrations of people/undead. A horse at a walking pace is quiet, especially on a dirt surface. Possibly make socks for them to muffle hoof sounds on pavement. Horses will not be stopped by pileups on the road. Downsides: Given the supplies you are taking you likely need between 5 and 15 pack horses for a group of 10 people (.5 to 1.5 pack horses/person) A pack horse can carry about 120 pounds to 250 pounds (sources vary), and keep up with a mounted person. I suspect that long hauls require lighter loads. In usual travel mode, pack trains moved 10-15 miles a day, with 12 miles (19 km) being typical. Speed was not great -- about 2 mph, maybe a bit more. Horses need time to graze if you are living off the land. They will need access to water. They can go further/faster if fed a grain supplement, but this increases the number of pack horses. Packing at the start/end of the day is fairly time consuming, taking 15-30 minutes per pack horse at each end of the day. Grooming is required, as is checking for raw skin from harness/packs, and always feet. The key to travel in your scenario will be to move quietly enough to avoid the zombies, and to find places to camp that are defensible. If you are quiet there will be zero or only a few zombies in earshot. You will need to stand watch at night, and you will need to guard the horses. Camping near natural noise sources (waterfalls, rapids, wind in the trees) and in places that naturally absorb sound (dense forest, box canyons, steep ravines, caves) will have merit. Given the general uncoordination of zombies, rough terrain may be more to your advantage. Most of the above have risks of being trapped too. Perfect campsites are going to be hard to find. Since zombies are attracted to noise, some of the preps you may want to try: * Find air powered rifles. Some were used in WWII as sneak weapons. Not as powerful as a conventional rifle but still deadly, and much much quieter. If one or more of your members has any skill with a bow, raid archery shops for arrows, although a head shot will be tricky. Crossbows are another fairly quiet option. * Build proper silencers for conventional rifles. A silencer doesn't make a weapon silent, but it reduces the noise by a lot. Instead of attracting every zombie within a mile, you may only get noticed by ones within 300 yards. Silencers make the rifle heavier, change it's balance, and interfere with the sighting picture. A good silencer is likely to be the size of a can of tennis balls. * Noise makers. Having units that can be set with a delay and then make a lot of noise for a few minutes may be the trick to getting away. Such devices should be rugged, and have timers for how long to make noise. Some may be programmable to turn on and off repeatedly. * Poisons. Stop by a gold mine and get bulk cyanide. Zombies have some sort of metabolism. Cyanide binds to hemoglobin rendering the blood supply useless. A dead horse slathered with a paste of cyanide may kill off the immediate crowd. * Gasoline flame bombs -- set as booby traps. Quarter stick of dynamite in a milk jug full of gasoline might ruin a zombies day. * snares. That shuffling pace lends itself to snares. Part of your defence perimeter is lines with slip loops a couple inches above the ground. It won't kill them, but it you catch them they have to take time to untangle themselves. Given the number of missing fingers this will take time. Following zombies will trip and fall over the snared ones. The effect will be to smear a mass attack over time, allow you shotgun reloading time between waves. Programmable noisemakers may be used to wear out a bunch of zombies. Set up two 500 meters apart. One goes off for 5 minutes. Zombies stream toward it. 5 minute silence. Zombies start to disburse. 2nd one goes off, zombies stream toward it. With the right spacing and timing, you can keep them sloshing back and forth like a wave in a kiddy pool. Eventually they run out of energy. Having one or more zombie dogs will be useful. These are dogs that are trained to detect the faint trace of the undead that they leave behind. The dog is trained to figure out which way the zombie was traveling, and silently indicates which way. If zombies have need of water, then traveling sections of land that are dry for miles may be effective. Load up on enough water for a night when you can, and camp on a dry ridgeline. This may allow a much smaller watch to be kept and give everyone more time to rest. This will require extra horses. Water is heavy. You will need several gallons of water per horse. [Answer] A travel trailer that can be attached to a truck or mounted on a track bed. For example Man TGL with 6 tonnes loaded burn around 25 litres for 100 km. It have have fuel tank that can take 400 litres. So on one tank you can go 1600 km. A travel trailer can be detached and truck can have more km/l while still having place for two people to sleep, eat and store things. MAN trucks are widely available in Europe in ALL versions. So you can easily adapt extra functions like windlass (from firetrucks), rams, communication arrays or medical shelf, there is something for every need so you can easily switch, add or remove needed items. For extra need I would suggest using minibikes. They are light, fast, have small l/km and you can store 4 of them at the back of the cabin. Using trains or railroads is not very smart. One train wagon can weight to 40 tons. Try to remove 8 of them. It would be very, very time and resource consuming. Especially when all the utility trains use diesel fuel. Which you can burn in your truck. [Answer] I'll offer a completely immediate and ready-to-use solution, because effort is nice but no-effort is nicer. I assume you have useable roads, otherwise I strongly suggest your I will single a particular vehicle out, but really the point is it's hybrid and rather common. It's an MPV for size, you might choose an SUV instead if available, or you could get away with a convoy of compacts. There are other brands, other models. If your survivors have internet access, they can check all these vehicles for size, consumption, and popularity. Or you could just conjure up a fake model. *#NotAnAd, but I will take checks if you offer them.* Aim for a Toyota dealership and pick the most expensive (no reason to pick a cheap one, is there?) Prius+ in stock. Or maybe you just already own one, lucky you. But okay, **why a bloody Toyota Prius+?** * It's a 7-seater. You can fit 10 people. Not much room for supplies beyond some MREs and first aid kits, but you can squeeze more if you start removing seats and useless panelling. * It's a family vehicle, which usually means great safety rating (unless you removed all the seats but who would do that?), but more importantly that means handy compartments in the front and a roof rack option. If you are lucky, they might even have it installed and the trunk that goes with it * It's fuel efficient, which is both nice for the environment and in a zombie apocalypse. If anything, it will make stopping for refuel less frequent and shorter. * It's got an alleged range of slightly above 1000 km, which is likely a lie to begin with, and will certainly be less true with 10 people onboard. Still, more than enough range you won't have to stop more than once for each city you visit. * No data on battery-only range for an overloaded vehicle (really disappointing), but I would expect 5-10km, maybe 20 in absurdly ideal conditions. But it's enough range to pass through some heavily zombified areas running all electric, aka silent. * It's got a GPS and the radio. GPS are great for navigation (not that a gool ol' map can't do the job), and radio is great for picking up signals like "hello, this is Radio Safety where we tell you where it's safe to go." There's probably a USB port to recharge your smartphone too, how convenient. * It's a common vehicle, meaning you can always find a fresh one if you have to. You might even have the luxury of picking the color you want. Now the caveats: * It's a Prius. It's not armoured nor combat ready. You'll be fine if you drive around zombies, not so much if you drive into trouble. * It'll work on dirt roads, but, and particularly since it's overloaded, don't ever get close to muddy areas. You'll have to stick to roads, but the good news is only you decide how clogged the roads (or kerbs) are. * Any global warming denier might shoot you in the face out of principle for driving an hybrid, but I surmise this is a rather low risk. --- Additionally, and that's true for any vehicle, if you have internet access and a smartphone, there might be a Waze-like app but with a zombie horde signalement option. If there isn't it might still signal law enforcement or safe heavens (provided other survivors use it and don't want to kill you). [Answer] I don't know why anyone hasn't suggested it but the best vehicle would be an armoured car like the ones used by banks. It's already lightly armoured and comes with run flat tyres. It's got a powerful engine and is quite capable of pushing abandoned vehicles off the road and just driving over zombies without taking any damage. It's diesel so fuel is common and could be run on cooking oil in a pinch They're also common enough that survivors could easily find one which I think is the key. Sure other vehicles might be better but they are not common and easily found. Any city will have several depots with them and they could be found on motorways or small towns if they were making a delivery at the time. You could use it as is or you could make some simple modifications like a roof hatch, gun ports and a plow to clear the road The other thing is that you'd take two vehicles. If something happens to the first vehicle, you have a recovery vehicle or everyone could keep going in the second in a pinch. It would also allow you to refuel more easily. The first vehicle parks at the fuel stop and shuts down and keep quiet. The second vehicle draws the zombies away by honking the horn. Once safe they can refuel in peace [Answer] I think one of these Iveco or Kamaz heavy trucks would be the ideal platform. They have huge fuel tanks and can go pretty much anywhere. Absolute units. <https://www.youtube.com/watch?v=XN9JdCOZeTc> [Answer] Rather than focusing on the vehicle (the road-rail option seems like the clear winner there, especially if you pair a truck with a road-rail back-hoe or JCB for defense and heavy removals), I'll look at modifications. It looks like there are a few main areas of risk that we'll want to avoid or evade. 1. The car chase. This is already handled multiple ways, by going off-road, or onto rail, or using the tank-like abilities of the JCB. Realistically, this would never be a thing in a post-apoc world, but it makes for a good narrative. In reality, you'd have ambushes. So you wouldn't chase someone because they might be ambush-bait. Chases are only worthwhile if you *know* there are unlikely to be ambushes to be led into, you *know* you outgun your quarry, and you *know* you can outrun them, and you *know* they are carrying something worth the expenditure of your resources to get, and you know you can get that by chasing them, without destroying the prize. Given how unlikely all these things are, why would any gang even equip themselves for the possibility? 2. Ambushes/Checkpoints. Avoiding roads, and having a hardened battering-ram/shield vehicle to either force a path through or shield the other vehicle's u-turn seem like the best plans here. A rail ambush generally relies on derailment being a show-stopper, so road-rail cars should cope better than most against these. However, setting the points to divert into a cutting might still work if the drivers are not careful - and well-timed point-switching can also split the convoy. 3. A breakdown or crash. Multiple vehicles reduces this problem slightly, in that one may be abandoned, at a high cost, but unless every vehicle can take 10 people, there's a limit to the attrition you can handle there. Having a defensive barrier to protect the repairing engineers may buy valuable time. Bring cutting and welding tools, and spare wheels, because your armor WILL get smashed into the wheels, grinding you to a halt, and meaning you need to quickly cut the armor away, replace the wheel, and get moving again. If the axle is also damaged, you'll need to give up on the vehicle. Protective skirts around the vehicle are a good idea anyway, for protection during any repairs that need doing under the vehicle, and protection against having the wheels shot out. However, they will reduce ground clearance, and risk being bent into the wheels in a collision. 4. Bogging down or sinking. Inflatable pontoons attached to the vehicles might be good for this, allowing the vehicle to become a raft. But this is likely to be prohibitive in terms of prep-time and power requirements and pump equipment, compared to the likelihood of the risk. However, it might make a good "hail mary" to just bolt a bunch of self-inflating life-rafts to the side of the vehicle, with the trigger strings pullable from inside. Almost certainly not useful for flotation, but they *might* be. And they *might* help right the vehicle if it tipped, smother a fire, knock off boarders, provide a little temporary collision padding, and more. But for the most part, a JCB to dig them out works better against mud, while rivers will just have to be detoured or crossed at bridges or fords. For this, metal pipe to lift the air intake and the exhaust up to the roof will at least prevent the engine getting swamped while fording, at the expense of fuel economy. 5. Foraging. Fuel will be the main one, but if stocks were low before the trip then medical and food/drink supplies may need to be refreshed too. A giant fuel tank could be brought along but is also a liability and may need to be abandoned. In all cases, the best protection is to not expose themselves. Since gas pumps are very unlikely to work (they need power, a telecomms infrastructure for the card, etc), the most useful improvement for foraging fuel would be a giant pull-along tank. Alternatively, or ideally in addition, they'd craft themselves internal access to the gas cap, a fuel pump, and a trap door in the floor with protective skirts, so that they could go down, open the fuel manhole in the ground, and pump it out into their own tank, without exposing themselves. Foraging needs the ability to jump out and back in fast. It is likely that there'll be a situation where people will need to cling to the outside until they've reached a spot where it's safe to let them in. Also, during car chases, stuff might need doing outside the vehicle. Both of these need handholds. Gun ports can double as handholds, which also prevents them being used by bad guys (they get their fingers machete'd off if they try! Or the gun ports can simply be closed). 6. Cities. 5-6 of them at 400km increments means you're driving 2000km. Every one of them will have gangs, blocked streets, and other problems that will make driving the convoy through very hard. Circumnavigating by ring roads is ideal, but not always possible, especially if you want some cool landmarks in your story, perhaps because they have to rescue someone in the middle of the city. Even if they don't penetrate city center, EU cities seem to have more built-up urban sprawl than US (or at least, TX) cities, so the same problems may be encountered even in the outskirts. 7. Tires. One of the major advantages of the rail system is that tires become a backup rather than the required method of driving. On roads, raiders will set traps with roadblocks, stinger systems, caltrops, and so on. Sure, you can't steer without road wheels, but at least you have more options than "stop dead and change the tire". Still, some system of fast-changing the tires would be good - run-flat tires would be ideal, but if they're just making what they can from what they can scavenge, then at least power-tools to change the wheel fast (with hand tools in case the power fails). Someone can possibly crouch in the JCB front bucket to change the wheel and be protected from most light arms fire, but not from zombies. Any of these risks may result in asset abandonment. When abandoning an asset, it's traditional in stories to never refresh that asset. This drives the narrative forward, but often just seems silly to the reader, and is a missed opportunity for further adventures. If you lose your fuel tank and you're not far in, then getting a new large fuel tank seems like a valid subgoal, and adds a diversion and interest to the story. If you lose your backup vehicle, then you no longer have a backup - getting a new one seems a valid subgoal. And so on. Also: I say "gangs". These are super unlikely to be the kind of Mad Max punk gangs that people imagine in the post-holocaust world. Instead, they'll be communities of people who are out to survive at any cost. Their turf will be heavily armed and armored to defend their protected resources. Their foragers will roam out to scavenge, but they will avoid non-cooperative contact with other forces unless they have to. Perhaps both are after a resource that they *must* have; or the encroaching people pose a risk to their defenses, perhaps by having a JCB that's moving their roadblocks out the way; or the encroaching people have something they need to survive, such as decent escape vehicles. For the most part, though, it is simply *not worth* investing in potentially deadly combat when there is so much scavengeable stuff where people won't be shooting at you. I feel that the default for two groups of survivors meeting in Europe will generally be cautious cooperation, preferably at a distance; I believe in the US competition might be an equally likely outcome, since a competition-based, zero-sum-game worldview is much more common here. So, in Europe, people will hail each other, shout or signal warnings about activity seen, and so on. They'll leave signs for other survivors, and make efforts to make contact, albeit silently. So the last modification I'd suggest, is as many communications methods as possible. Walkie talkies (with chargers!). A ham radio or at least a CB. Flags. Flashlights. A morse code book. Information is king. In that light, one of the best tradables (as well as very useful for survival) will be useful ebooks on survival, and readers for it, and chargers for them. [Answer] Assuming your group can get their hands on one, I would consider an infrantry fighting vehicle such as a [Bradley](https://en.wikipedia.org/wiki/Bradley_Fighting_Vehicle). * They can hold up to nine * They can handle rugged terrain * They use diesel which is almost as easy to find as gasoline and can be stored for slightly longer. * Their arms and armor will be very helpful against the undead, or antagonistic survivors. There are a few disadvantages: * Most IFVs, including the Bradley, are wide enough that it would be problematic to drive them on roads that might be blocked by abandoned cars. * They won't have many of the creatures comforts of most other modern vehicles. * The gas mileage is horrible. Even so, those disadvantages are probably outweighed by the advantages in a zombie apocalypse, especially if most of the area you need to cross is relatively flat off-road region. ]
[Question] [ **Closed**. This question is [opinion-based](/help/closed-questions). It is not currently accepting answers. --- **Want to improve this question?** Update the question so it can be answered with facts and citations by [editing this post](/posts/75073/edit). Closed 6 years ago. [Improve this question](/posts/75073/edit) Inspired by [this question](https://worldbuilding.stackexchange.com/questions/74991/i-was-thrown-into-the-middle-ages-how-do-i-power-my-time-machine) about a time traveller. So, I've travelled to the medieval age. Think 12th / 13th century Europe. Unlike the time traveller in the other question, I did bring batteries for my time machine, but I want to have some fun while I'm here. So I need to impress the locals with some gifts to get them to do things I'd like to see them do. I thought about bringing bolts of silk and sacks of spices. Unfortunately, I spent all my money on my time machine. So I need some suggestions. Here are my criteria: * Must be interesting and valuable to medieval people, enough so that they'd at least give me free food and lodging in exchange, and maybe put on some shows and generally give me a good tourist experience. * Should not have a very large impact on medieval society. I'm not trying to cause a technological revolution here. * In our time, it should be within the means of the average person to afford - the cheaper and more common it is, the better! * Ideally should not leave lasting archaeological evidence. So, no plastic bags or running shoes. [Answer] **Rubber** No seriously a cheap waterproof rain slicker or pair of rubber boots will bribe the average person very easily, waterproof materials were nonexistent. It is also really easy to demonstrate and you can buy them at a dollar store. The best they had at the time were merely water resistant materials which tended to stain since they were soaked in oil. Plus there is no risk of accused of black magic like you might with medicine or any other active chemical. Plus it will rot away in a few decades so no evidence, as long as you don't pass out hundreds of them. **Nails** Nails were valuable enough to be major market item becasue they were time consuming to make. But at the same time, they were common enough that anyone would recognize and want them. Small furniture nails were even more valuable. A box of nails both valuable **AND** easy to fraction out (20 nails for a piece of whatever I smell cooking), and would not draw that much attention, since they did exist. you can buy square/box nails at any large hardware store, The process is different but the finished project will be identical. **Salt** is just easy its desirable and easy to come by, sea salt is considered more desirable, **spices** are more tricky. You could easily be accused of selling poison or being a smuggler or get your friends accused of the same. **Cotton** Go buy a few bolts of cotton cloth from Walmart. You can trade each one for a month of food and shelter without much problem. Go with tan or off-white to reduce suspicion. Remember: you don't want to give out too much wealth because it just makes those people a target. Cotton was known at the time, but it was traded from India at a high cost. Just buy "all natural" or unbleached cotton. **Wooden dice** Easy to carry, dice were common, boredom is universal and you can buy them at any craft store cheap. **Sewing needles** Light, easy to carry, you can buy them at Walmart by the hundreds for pocket change and everyone in the medieval society will see their value. Go with big over small however, the cloth of the time was rough spun. **Combs** Even metal combs are cheap, pretty, and combs are universal so that anyone with hair will see their value. Just get simple designs and any archaeological evidence will be too corroded to look out of place. **Mink oil** made of mink oil and lanolin is used to waterproof leather. Waterproofing would always have been valuable at the time and both ingredients were available and used. They were just a pain in the ass to get in any quantity. Heck, you could just buy a tub of **lanolin** at any fabric store - years worth of work in one tub! As Zwol mentioned many goods had monopolies or defacto monopolies (guilds, charters, patents, ect) in certain countries so you could get your friends in serious trouble, so far as I know none of these had monopolies at the time although some did develop ones several centuries later. This is also why I left things like purple dye off the list they were far more restricted and not something you want your friends to be caught with. For more ideas, I recommend the video series "worst jobs in history" to get an idea of what was valuable at the time. [Answer] There are a few options: 1. [Aluminum](https://en.wikipedia.org/wiki/Aluminium#History). Until modern times, it was essentially impossible to produce in any significant quantity, making it far, far, far more valuable than gold. It is also a useful metal in its own right, being strong and light. And it should break down [within 500 years](https://www.csuohio.edu/sustainability/fun-stuff-and-fast-facts), so it won't leave any archeological evidence in the modern day. Price: free if you are willing to dig around in some trash cans. 2. [Candles](https://en.wikipedia.org/wiki/Candle#History). The candles affordable to medieval people were very smelly, and odorless candles were too expensive. Price: About 20 dollars for a box of [100 small candles](http://rads.stackoverflow.com/amzn/click/B01N45PXG6) or [12 big ones](http://rads.stackoverflow.com/amzn/click/B007Q7VDV0). 3. [Paper](https://en.wikipedia.org/wiki/Paper#History). Paper at the time was made from rags, and thus much more expensive. They probably wouldn't have much use for it themselves, but the nearest monastery would appreciate it, and the village would be eager to impress the Church. It won't last long, though, especially if you pick low-quality paper that degrades quickly. Early paper used cloth or animal skins that last much longer than modern wood pulp paper, especially cheap paper. It will seem good as long as you are there, but won't last a century not to mention 6-7 centuries. Price: About [20 dollars](http://rads.stackoverflow.com/amzn/click/B00C1IL422) for a box of 5000 sheets. 4. [Salt](https://en.wikipedia.org/wiki/Salt#History). Salt was extremely important part of the diet that was hard to come by for most people for most of history. It was also critical for preserving food. Price: About [20 dollars](http://rads.stackoverflow.com/amzn/click/B007SNJ98G) for a 25 pound bag. 5. [Spices](https://en.wikipedia.org/wiki/Spice_trade). Also critical for preserving food, but had to be imported from Asia and India. The crusades were largely fought over disruptions to the spice trade. Price: less than [5 dollars](https://www.amazon.com/s/ref=sr_st_price-asc-rank?keywords=steak%20rub&rh=n%3A16310101%2Ck%3Asteak%20rub&qid=1490282282&sort=price-asc-rank) for a 5 ounce bag, probably good for dozens of meals. 6. [Dyes](https://en.wikipedia.org/wiki/Natural_dye). The cheap synthetic clothing dyes didn't exist, and several colors (particularly blue, purple, and some shades of red) were extremely expensive to make. Price: about [20 dollars](http://rads.stackoverflow.com/amzn/click/B01FV60TAS) for a small kit with various colors. 7. [Silk](https://en.wikipedia.org/wiki/Silk). Although still more expensive today than other fabrics, it is much, much, much cheaper than it was due to modern western silk production. Price: Less than [15 dollars](http://rads.stackoverflow.com/amzn/click/B00HR53DUK) for a silk shirt. 8. [Fertilizer](https://en.wikipedia.org/wiki/History_of_fertilizer). You can buy it by the carloads and it would have helped their agriculture immensely, although getting them to recognize its advantages may take some time. Price: Less than [15 dollars](http://rads.stackoverflow.com/amzn/click/B0030EK5JE) for a decent-size bag. 9. [Pesticide](https://en.wikipedia.org/wiki/Pesticide#History) (thanks Richard U). Would likely work much more quickly than fertilizer and is even more important. Price: Less than [40 dollars](http://rads.stackoverflow.com/amzn/click/B0053SDELG) for a large bag of insecticide and less than [30 dollars](http://rads.stackoverflow.com/amzn/click/B007ICK5RG) for a large tub of rat/mouse poison. 10. [Perfume](https://en.wikipedia.org/wiki/Perfume#History). Apparently at the time bathing [was not popular](https://en.wikipedia.org/wiki/Hygiene#Hygiene_in_medieval_Europe) in northern Europe, perfume was used instead. Price: You can easily get a probably several month supply for less than [15 dollars](http://rads.stackoverflow.com/amzn/click/B00VAO8O44) or air freshener for [less than a dollar](http://rads.stackoverflow.com/amzn/click/B00E9OYDGU), although you would need to transfer it to some container than is appropriate for the era. 11. [Incense](http://www.triviumpublishing.com/articles/smellofthemiddleages.html). Another thing that was used more in churches, but again pleasing the Church is always a good thing in medieval Europe. Price: less than [15 dollars](http://w.amazon.com/Satya-Sandalwood-Midnight-Patchouli-Celestial/dp/B0016D4RQS) for several months worth. [Answer] Peppercorns. Lots and lots of peppercorns. During the middle ages they were as valuable as (if not more so than) gold, whereas today they are one of the cheapest spices you can buy, giving them the highest yield on your investment. Similarly, salt was very valuable, though you would have more luck with that one if you went back to the Roman ages; during the late middle ages salt was still valuable, but much of the Roman empire's infrastructure was built to facilitate the transport of salt to Rome. If you just wanted to mess with the natives, might I recommend a [wrist-mounted fireball launcher](http://www.ellusionist.com/pyro-mini-fireshooter.html)? Convincing them you are a wizard who can incinerate them with a gesture could be a very effective method of getting them to do what you want. [Answer] # Deodorant True story: my brother, on his second tour as an Infantry officer in Iraq, asked for a box of deodorant in the mail. Turns out, everybody wants it. Village elders want it, housewives want it, kids want it. This stuff is pretty amazing when you think about. Makes you smell nice all day. People paid a lot of money for perfumes in the Middle Ages. For dirt cheap you can give them some smellgood that really works. You'll probably want to get the deodorant out of the plastic tubes and into something more biodegradable, but that doesn't make it any less useful. [Answer] **Sugar** People are nuts for the stuff. Sugar was viewed in the Medieval period as a medicinal item. That it tasted good and could be turned into various forms such as syrups and pills was a great advantage and it also helped to counteract the bitterness of some of the medicines in which it was an ingredient. It wasn't until the 18th century that sugar ceased to be considered as a drug and a spice and became a basic staple of daily life. It was also fairly expensive, with a small bag of it being equivalent to a day's wages. [Answer] Nails -- These were hard to make -- A box of 5000 would be a good bribe for certain groups, especially smiths for shoeing horses (although this may require specialty nails) [Nail usage in the middle ages](http://www.bloodandsawdust.com/sca/nails.html) [Answer] Simple drugs, such as Ibuprofen. Cheap presbyopia glasses. They are sold on the street for a couple of Euros in several Balkan countries and though not fitting the person exactly, would still be invaluable to them. It would be very hard to remake them, even if you get a pair. No need to fear causing a technical revolution (which rules out clocks, the dissembling of which would probably cause a lot of innovation). They were invented some time before 1286, but still very expensive. EDIT: There is this painting by Conrad von Soest, from AD 1403 showing the use of spectacles. So the best method would probably be to just give them the lenses - which were the veeery expensive part - and let them fashion a contemporary frame. Alternatively, you could gift them monocles with metal frames. [![enter image description here](https://i.stack.imgur.com/fFvyG.jpg)](https://i.stack.imgur.com/fFvyG.jpg) Cheapest window glass. There was window glass, but it was not affordable. Shaped glass objects, like a teapot. Glass was blown and thus valuable. If in a Christian country: tiny printed pictures of saints. The Greek Orthodox Church gifts them to people. They are colourful and saintly and would surely impress them. Edit: I see that pocket knives and lighters are excluded by the evidence-clause. [Answer] Soap. Rich people had it, but it must have cost way more money than it does now, so just sell that, get gold and make the trip a few times. --- To add some historical facts, see for example this price list: <http://medieval.ucdavis.edu/120D/Money.html> Soap isn't in there, but I think it might still provide a good source also for other answers. And searching for soap in the middle ages does provide sources saying it was a luxury good and used by rich people. No links there because I didn't find a single good source, but many secondary/tertiary/x-iary sources. [Answer] 1. **Colored glass marbles**. Glass was a pretty expensive material in Middle Age, only the richest could afford having glass on their window. You could pretend they are like moneys for you. And the natives may use them as pearls. 2. **Pyrex Glass bottles**. They might have bottles, but yours are heat resistant. 3. **Match boxes**. For a society relying on fire for heat and light generation, having it at the snap of a finger would be a definite plus. 4. **Mirrors** (both flat and curved). [Answer] Fabric was extremely time intensive to manufacture. Pure white was almost impossible to get in fabric. You can get six pairs of white athletic socks for $9.99 from Costco. Everybody needs clothes and a clean pair of white socks would be seen as a luxury. [Answer] Blue colored fabric would be a *very* expensive commodity. Blue was considered a royal color, not because of law, but simply because it was very hard (and thus expensive) to make a good quality dyes. Poor-quality blue dyes where typically made from the [woad plant](https://en.wikipedia.org/wiki/Isatis_tinctoria), but this gave a rather pale blue color that has bad resistance to sunlight. A better quality pigment was made from [ultramarine](https://en.wikipedia.org/wiki/Ultramarine), but this needed to be imported from Asia. Show up with dress like this (not nesecarrily this model, but this color) ![dress](https://images-na.ssl-images-amazon.com/images/I/41B1bHuLo9L._AC_UL260_SR200,260_.jpg) and you should be able to catch the attention of the rich quite quickly (because you would be the *only* person with a fabric *this* blue). Any fabric of course nicely fits the requirement that it should not leave lasting archaeological evidence. *Alternatively*, you could opt for a bottle of [Eau de parfume](https://en.wikipedia.org/wiki/Perfume), an item that could be in the same price range as a nice blue dress, but considerably easier to carry around. It would be harder to simply show off in order to attract the attention of potential buyers [Answer] ## Safety matches Cheap, small, lightweight, easy to use, obviously useful and *they get destroyed as you use them!* [Answer] **Instant ramen noodles**. So incredibly cheap: you can get it in most convenience or grocery stores for less than $1.00 per serving, but you would need to transfer the packaging (perhaps place the noodles in a cloth sack, and the flavoring/seasoning oil in a jar). Food is biodegradable so no traces of it will be left behind, and it is valuable as a quicker, cheaper, (and possibly more delicious depending on individual preferences) alternative to pasta/noodles made in the medieval times. This would also have the advantage of being a novelty item, compared to other items that might be cheaper to produce in today's society but aren't necessarily new inventions. [Answer] The other answers are great, but tend to focus on luxury items, and items that are valuable because they are scarce at the time. Hand tools, quality made hand tools would be quite valuable. They will be instantly recognizable and testable by most people you are willing to trade with. Additionally, your potential buyers will actually benefit from these items materially (their work will be made easier), and thus may be more willing to trade. These tools, being useful and only slightly different in design than they already possessed, will be worn out and discarded or melted down when they reach the end of their life. My particular choices * [Estwing Metal Hafted Hammer](http://www.estwing.com/s_drilling_hammer_long_handle.php) They come in Many varieties, but this particular one will be tremendously useful to most laborers. The metal haft means they will get many years out of work before it fails. They will love not having to replace the handles. * [Retractable utility knife](https://rads.stackoverflow.com/amzn/click/com/B015R4LD2M) and [blades](https://rads.stackoverflow.com/amzn/click/com/B015W3AKDQ) These blades will be sharper and last longer than any knives that they have. Additionally They can be sharpened, although we never do, and your customers will already know how to do that. Make sure to select a tough body, and one that doesn't require tools that they won't have to change the blades. * [Bow Saw](http://www.svensaw.com/) and [Blades](https://rads.stackoverflow.com/amzn/click/com/B0001IX71U) This one will blow their minds. It is a bow saw that packs down nice and compact. Otherwise, it is valuable for the same reasons as the utility knife. Bring a few extra blades. [Answer] Antibiotics. Not just in the medieval ages, but up to the early XXth century was extremely easy to die of all kind of bacterial diseases and common infections. You can sold a 3$ box for 30000 pieces of silver to your local noble. Once you are famous enough, you can get to treat the king's daughter and maybe you can tourist your own earl or county. [Answer] Many good answers (spices, fabric, soap, etc) but I have to add a few excellent options 1. Sugar, Chocolate, or any type of candy - 50lbs bag of sugar sells for ~ \$20. Chocolate is more expensive - maybe \$100 - \$150 for 50lbs bag. When sweets became available in Europe, there was a huge craze about them so that would sell for sure. 2. Coffee, tea - again became hugely popular in Europe when they became available 3. Opium - more sinister but could be sold as pain reliever? 4. High quality steel - ulfberht swords were made of high quality Damascus steel and were super sought after so if you are going in to the early middle ages, you are golden. [Answer] Potentially Glass Mirrors, you can obtain glass mirrors relatively cheap these days along with a good reflection. Back in Medieval times Mirrors would not of been too plentiful with only the rich having access to them and certainly not being as big or giving the crisp images as they do these days. Glass was around in some form or another, and polished metal mirrors have been around since the Bronze Age. [Answer] **GOLD** So for some stupid reason this question got stuck in my mind all damn day.. There is an obvious answer that nobody seems to have mentioned mainly due to the pricing however for a couple grams of gold you could have a blast for a while: current prices <http://www.apmex.com/spotprices/gold-price/> Also since you're in a time machine you could prolly jump back to before reported findings of gold in some locations and pan for a few days prior to your middle ages trip (unless of course the time machine is limited to only 1 return trip) [Answer] Alcohol and tobacco can be good for bribing. It can be different kinds of alcohol, for example some strong staff and also some vines and beer. Of course, they had some alcohol drinks, but it's always interesting to try some foreign beverages. And regarding tobacco, I think they will be interesting in cigarettes, which didn't exist in this time yet. [Answer] ## Condoms. Seriously :D They are cheap, you can pack lots of them and [it is plausible they was desired goods](https://en.wikipedia.org/wiki/History_of_condoms). Also, latex comdoms should be biodegradable in 50 years ([source](https://answers.yahoo.com/question/index?qid=20070120025913AAERK7G), [source 2](http://learn.condomdepot.com/2014/11/07/are-condoms-biodegradable/)) so no surprise for Indiana Jones. I have no idea whether the medieval church was against limiting reproduction or not, but i doubt it: simply put, they can not be against something that does not yet exist... Anyways, you can just keep yourself under radar or exactly the opposite: you can stick with somebody powerful who does not care much about church & care about not having illegitimate children ;) ) [Answer] Pretty picture books. Or paper notebooks. Paper degrades. Jewelry made from rare and exotic materials (i.e. cheap and small plastic beads that will break in a few decades). Explosives, like dynamite. You can even hide a 10 year timed fuse inside. [Answer] How about **[glass beads](http://www.pandahall.com/wholesale-glass-beads/208.html)** and **[silver beading wire](http://factorydirectcraft.com/catalog/products/1302_2533_1204-5619-silver_beading_wire.html?ccset=US&gclid=CjwKEAjw5M3GBRCTvpK4osqj4X4SJAABRJNC-Uhp2lpT7uTqrgw5KY2bHIzpRDl9wWT3C2TIcEXB-RoCXwjw_wcB?)**? Neither are expensive, nor weigh much. They would take very little room and you could sell beads individually or as jewelry. How about sewing needles? They'd need a larger eye to accommodate the thread of the time. You could also being plans for making simple machines like a treadle sewing machine -- the kind used before electricity. Knowing how to make all those sorts of machines would be useful. How about knowing how to make wooden matches? They were not invented until 1826. Windmills may not have been where your character is at that time. [Answer] **A Catholic Bible or Quran**. Religious books are relatively cheap in present times but in the middle ages, the majority of Bibles were only owned by Churches. Having one in the palm of your hand in would instantly elevate your status to a "Man of God" and grant you the ability to have the "fun" you desire. Trading or selling the Bible to a noble would be very profitable, but conversely, you could potentially overplay the Bible and use it to influence others, depending on your level of morality. (Think "messenger from God") Now this comes with some risks, due to the church being very curious and powerful, so this would be something you could do for a short time, but might be dangerous to overplay this role too long. Since paper breaks down relatively quickly, I wouldn't expect that a modern Bible would stay intact longer than a few hundred years. [Answer] A bucket of "Kernel Sanders" Special recipe Bet it would go down a treat with some mead. (Although they might have a bit of an upset tummy for a few days after) Just an observation I've made when I ate it last.... [Answer] I would bring back **Bic lighters**. Sure, they would leave some archeological traces, but they would never be able to recreate them. You could explain **EXACTLY** how they worked, so that you wouldn't be seen as a witch and most users would likely try to take it apart to attempt to recreate it, but fail miserably due to the fact that the lighter is made of plastic, held together by a gluing and melting process that could not be mimicked at the time and they wouldn't be able to refill it as they have no access to compressed gas. Each one would be worth a fortune so you wouldn't have to bring much. I would imagine you could do a grand tour with the value of only 1 lighter. The metal components of these lighters break down quite fast. I found one in my garden in my backyard and only the plastic remained. The item, when finally disposed of, would likely be a broken pile of plastic bits that archeologists wouldn't even know what it was. [Answer] **Ballpoint pens**. Although not many medieval people could write, the (mostly rich) people who did would certainly be willing to trade for something as usefull as a simple pen. You can get cheap plastic ones for around 10 cents a piece, or biodegradable ones for around $1.50. [Answer] **Spices** - dirt cheap in the UK in large bags from a Chinese supermarket (much cheaper than Tescos/etc.!). Won't arouse suspicion as being an odd item - especially if you pick ones known to them - and would fit with an "I'm a traveller, I picked these up in lands afar" image. Easily portioned out for smaller values. You're unlikely to step on anyone's toes unless you encounter a major merchant. Don't go for salt - one wet day and you risk losing it all if your bag isn't water-tight! **Paper** - very valuable in olden times, very cheap now. However, it might arouse some suspicion as to how high quality a modern ream of 80gsm paper is by their standards. You'll need to find the right people to sell it to though, but it could get you quick access to higher society. **Light** - once prohibitively expensive, now unnoticeably cheap (<http://www.bbc.co.uk/news/business-38650976>). I suggest reasonable-quality hand-crank torches; they'll last a long time as long as you give them vague guidance not to kick them. Might raise some suspicion as 'magic', but hand-cranked seems safest - people can see that cranking is the energy source, there's no magic demon (lipo cell!) keeping it lit the whole time. Would be an extreme luxury item. **Pins** - compared to nails, very cheap and light, but very expensive in the past. Easily portioned out. No risk of being seen as magical/etc. Slight risk of being lynched by the blacksmith! [Answer] Fireworks! go for plain brown paper if possible Light them off, give a great show. Let the local alchemist look at a sample before lighting it off to avoid accusations of witchcraft. You could entertain the king with a good mortar show, or scare off the kings enemies with stories of a tame dragon and so on. Just make sure you light them all off. Evidence would be burnt and any leftover paper would get scattered and degrade in a pretty short period of time. Then you could at least let the newly enlightened king in on the concept of bathing regularly and not to dig the privy too close to the well. [Answer] **Antibiotics**. Granted, the [Black Death](https://en.wikipedia.org/wiki/Black_Death) will not be at its peak by then but people will understand the benefits of it... > > Must be interesting and valuable to medieval people > > > Well, you will have to play this right since you have to prove its worth first. This is a major drawback of this technique as you cannot instantly trade it in for the favours. The other issue is (as [John's answer](https://worldbuilding.stackexchange.com/a/75175/401) suggests) potential trouble with the clergy and other superstitious people. So, yeah, there is a certain risk involved here. > > Should not have a very large impact on medieval society. I'm not trying to cause a technological revolution here. > > > Given the limited supply you will provide and no way to learn the secret of how to make it make it from the mere posession of a few samples, a techological revolution is unlikely. What will happen to the course of history if people survive who would have died otherwise is of course a very different question. Depending on what you think of the butterfly effect the time traveler being there might be trouble enough. > > Ideally should not leave lasting archaeological evidence. So, no plastic bags or running shoes > > > Pick a dosage form and re-package to avoid plastics - sounds doable. [Answer] Honestly, in order to make any impression on the archaeological record, you would need to both be very lucky and hand out hundreds of whatever it is you are giving out. Couple that with the fact that archaeologists are very particular with documenting everything so as to avoid site contamination, and you've got an interesting situation: they might find modern items, but those items would be unlikely to spark much archaeological interest, especially if the markings on said items included the date of manufacture. Finding such an object in a drawer of an ancient dresser would likely result in no more than a frantic search through the camp for the idiot who put it there. The only way they would discover anything is weird is if they actually looked close enough at the items to figure out that they have actually aged enough to have been placed there a long time ago. So, if you ask me, you've got three options for the types of things you could bring: 1) items that already existed at the time, were rare, but which are abundant, cheap, or easy to come by in modern times. 2) items that degrade completely in a short amount of time, like paper, food, etc. and 3) items that degrade very little with time so as to make it difficult for an archaeologist to actually notice degradation without procedures that are too expensive to justify running on, say, a smartphone. Note that delivering high-tech devices to someone from ancient history is not necessarily likely to kick of a technology revolution. Why? Well, understanding how a computer works takes a lot of complex mathematics and science that simply didn't exist in early human history. A person from that time period could spend their entire life examining the internals of a broken smartphone and never be able to figure out anything useful from the exercise. ]
[Question] [ I'm the owner of a large bank in Europe, with vast resources at my disposal. I would like to increase my wealth by lending it out at interest. The ruler of the country I'm based in has his own wishes: he wants to conquer the neighboring country, paying off some lords over there to join his side. The problem is, being a bit of a spendthrift, he needs a loan. I would gladly lend the money, except I know that rulers like to dissolve wealthy organizations and "redistribute" their assets, especially if they owe money to them. For example, one of the reasons that people of Hebrew descent were disliked throughout Europe (besides widespread anti-Semitism) is because they were known for lending money. The Knights Templar amassed a large amount of wealth as well, which later led to their downfall. What measures can I take to ensure that the King will not just decide that he owes too much money to me and confiscate it all? I would prefer: 1. No eventual execution on false charges, banishment, or impoverishment. 2. Eventually regaining my lent money plus interest, or something else of equivalent great value 3. (Optional) A maintenance of (at least outward) neutrality so that I can also lend to my king's enemies I would prefer a technology level/political system of that around the High Middle Ages, but that's not concrete, if sometime else works better. [Answer] So nice to have interesting questions to which real history provides a ready made and exemplary answer which is also a great tale to be told. # Consider the [Fuggers](https://en.wikipedia.org/wiki/Fugger) 1. **The beginnings:** It all begins with Johann "Hans" Fugger, who > > *"came from Graben to the free city of Augsburg as a Landweber in 1367. Through hard work and two marriages to good women, Hans left his family a large fortune on his death in 1408. His widow Elisabeth Fugger-Gattermann led the weaving and the textile-trading side of the business until her own death in 1436. She was helped in these areas by Hans and Elisabeth's sons Andreas and Jakob, who also learned gold-working as apprentices. Together the three of them built the family business into a thriving but still low-level business and in the first three decades of the 15th century made a considerable fortune."* (Wikipedia) > > > 2. **Early rise:** It then continues with his son [Jakob Fugger](https://en.wikipedia.org/wiki/Jakob_Fugger_the_Elder) "the Elder" (1398–1469), who took over the firm when his mother died. He worked hard and he traded harder, diversified into banking, and by 1460 he became one of the twelve richest citizens of Augsburg. 3. **The highest point:** *His* son, [Jakob Fugger](https://en.wikipedia.org/wiki/Jakob_Fugger) "the Rich", was born in 1459 and died in 1525. I know, this is more early Renaissance than High Middle Ages, but then he was a German, and in Germany the Renaissance started later than in Italy and didn't really do much to the social relationships anyway. Jakob was involved in the family business from an early age; by the time he was 14 he was already representing the firm's interest in Venice, where he will base his operations throughout his life. He married *very* well, taking for wife Sibylle Artzt, the daughter and heiress of a Grand Burgher of Augsburg, thus giving Jakob the opportunity to become a [Grand Burgher](https://en.wikipedia.org/wiki/Grand_Burgher) himself. The firm was now fabulously rich, giving loans to the pope, and to emperors and kings and grand princes left and right; this made Herr Fugger consider the very question, *how can a banker successfully and safely lend money to an autocrat?* His answer was to get valuable collateral, in the form of commercial and mineral rights: > > *"As collateral for loans that he had given to the Habsburgs and the King of Hungary, he demanded mine revenues of Tyrol and the transfer of mining rights in Upper Hungary to him. Through this method he eventually established a dominant and almost monopolistic hold on the copper trade in Central Europe."* (Wikipedia) > > > The firm started a lucrative business exporting European copper to India, from where they imported spices; arguably, this was the first large scale long-distance bidirectional trade network since the fall of the classical civilization one thousand years earlier. In 1519 Jakob Fugger entered into an agreement to fund king [Carlos I](https://en.wikipedia.org/wiki/Charles_V,_Holy_Roman_Emperor) of Spain in his attempt to be elected Emperor of the Holy Roman Empire; this was eventually successful, and King Carlos I became Emperor Charles V, in the process accumulating a debt of about 600,000 [guilders](https://en.wikipedia.org/wiki/Guilder) to the Fugger Bank. (That's about 2.1 metric tons of gold, or about 0.7% of the annual GDP of Europe at that time.) The point is that the newly minted emperor obviously could not pay back the debt, and Herr Fugger never had any misplaced hope that he would; instead, the firm of *Jakob Fugger und Gebrüder Söhne* (Jakob Fugger and Brothers' Sons) got even more mineral rights and *"all discussions of trade restrictions and limits to monopolies"* (Wikipedia) were quietly dropped. 4. **Gentle decline and gentrification:** Jakob Fugger II left the firm to his nephew [Anton Fugger](https://en.wikipedia.org/wiki/Anton_Fugger) (1493–1560), who expanded the firm into a worldwide trading house, from the Americas to the East Indies. Realising that a mercantile genius of the scale of Jakob II would never happen again in the same dynasty, and that times were changing, he set to trade the firm's riches for social positions, and he arranged marriages into nobility for his sons and daughters. Anton left the firm to his nephew [Johann Jakob](https://en.wikipedia.org/wiki/Johann_Jakob_Fugger) (1516–1575), who led a splendid life as a patron of the arts and sciences; under him, the firm suffered a great setback when Spain went bankrupt under the reign of [King Philip II](https://en.wikipedia.org/wiki/Philip_II_of_Spain#Economy). Johann Jakob had to save the firm with his own personal wealth; he then transferred control to his cousin Markus. However, the firm had successfully diversified and [Markus Fugger](https://en.wikipedia.org/wiki/Markus_Fugger) (1529–1597) proved that a solid financial and mercantile firm can overcome a sovereign default by a major world power. 5. **A princely family:** *"Anselm Maria Fugger von Babenhausen (1766–1821) was created Prince of the Holy Roman Empire in 1803. The present head of this branch is Prince Hubertus Fugger von Babenhausen who owns Jakob the Rich's former business seat, the Fuggerhäuser in Augsburg, as well as nearby Wellenburg Castle and the castle at Babenhausen, Bavaria (purchased by Anton Fugger in 1539 and today housing a museum on the family history); he is also co-owner of a small private bank, the Fürst Fugger Privatbank, in Augsburg."* ([Wikipedia](https://en.wikipedia.org/wiki/Fugger#Later_years)) [![Jakob Fugger the Elder](https://upload.wikimedia.org/wikipedia/commons/thumb/c/c1/Jakob_Fugger_d.%C3%84..JPG/121px-Jakob_Fugger_d.%C3%84..JPG)](https://en.wikipedia.org/wiki/Jakob_Fugger_the_Elder#/media/File:Jakob_Fugger_d.%C3%84..JPG) [![Jakob Fugger the Rich](https://upload.wikimedia.org/wikipedia/commons/thumb/c/c0/Albrecht_D%C3%BCrer_080.jpg/103px-Albrecht_D%C3%BCrer_080.jpg)](https://en.wikipedia.org/wiki/Jakob_Fugger#/media/File:Albrecht_D%C3%BCrer_080.jpg) [![Anton Fugger](https://upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Anton_fugger_by_hans_maler.jpg/101px-Anton_fugger_by_hans_maler.jpg)](https://en.wikipedia.org/wiki/Anton_Fugger#/media/File:Anton_fugger_by_hans_maler.jpg) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/9/9b/Christoph_Amberger_-_Portr%C3%A4t_Hans_Jakob_Fugger_-_1541.jpg/119px-Christoph_Amberger_-_Portr%C3%A4t_Hans_Jakob_Fugger_-_1541.jpg)](https://en.wikipedia.org/wiki/Johann_Jakob_Fugger#/media/File:Christoph_Amberger_-_Portr%C3%A4t_Hans_Jakob_Fugger_-_1541.jpg) [![Markus Fugger](https://upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Markus_Fugger_d.%C3%84.jpg/92px-Markus_Fugger_d.%C3%84.jpg)](https://en.wikipedia.org/wiki/Markus_Fugger#/media/File:Markus_Fugger_d.%C3%84.jpg) *(Jakob Fugger the Elder, anonymous portait. Jakob Fugger the Rich, portrait by Albrecht Dürer. Anton Fugger, portrait by Hans Maler zu Schwaz. Johann Jakob Fugger by Christoph Amberger. Markus Fugger, anonymous portrait. All pictures in the public domain and available on Wikimedia.)* # Summary * The key to giving loans safely to sovereign princes is to extract as collateral papers giving you some sort of lucrative rights. Mineral rights, land rights, trade rights, it does not matter; the important thing is to remember that you are dealing with powerful aristocrats, who are poor in terms of actual capital, have no understanding of trade and finance, but can easily sign their names on sheets of parchment giving you the exclusive right to open metal mines in Upper Hungary, for example. Moreover, the powerful but insolvent prince will feel that he made a good deal -- after all, he took your money, never paid it back, and all he gave you was his gracious consent to allow you to work! * It is wise to diversify, and to maintain a ready amount of capital to be able to overcome sovereign defaults. Before late modern times, sovereign defaults simply wiped out all debt; consider the fate of all the investors on the St. Petersburg stock exchange in 1918... The question mentions the difficulties faced by Jewish bankers. Jewish bankers are a special case, in that their religious affiliation made them subject to restrictive laws which prohibited them from owning real estate; how to make a medieval, renaissance or early modern state give up its anti-Jewish discrimination is a much more complicated problem, which I won't touch. Further reading: * Richard Ehrenberg, *[Capital And Finance In The Age Of The Renaissance. A Study of the Fuggers and Their Connections](https://archive.org/details/capitalandfinanc037633mbp)*, English translation by H. M. Lucas, London, 1927, available at the [Internet Archive](https://archive.org). ([Another copy](https://archive.org/details/in.ernet.dli.2015.263218).) * Greg Steinmetz, *[The Richest Man Who Ever Lived: The Life and Times of Jacob Fugger](https://rads.stackoverflow.com/amzn/click/B00P434F4U)*, Simon & Schuster, New York, 2015. (The link goes to Amazon.) --- **Excursus: What on Earth is a *Landweber*?** *"Jakob's father was Hans Fugger, who came from Graben to the free city of Augsburg as a Landweber in 1367"*, says Wikipedia, in the article on [Jakob Fugger the Elder](https://en.wikipedia.org/wiki/Jakob_Fugger_the_Elder). What on Earth is a *Landweber*? The literal translation would be "country weaver", which is not immediately helpful. The Wiktionary does not know the word, and neither does the [online version of the Duden](https://www.duden.de/). Dagmar Klose and Marco Ladewig's [*Freiheit im Mittelalter am Beispiel der Stadt*](https://publishup.uni-potsdam.de/opus4-ubp/frontdoor/deliver/index/docId/3268/file/phdl04.pdf) (Freedom in the Middle Ages Exemplified by the Cities) (Potsdam University, Potsdam, 2009, ISBN 9783940793959) contains this illuminating passage in section II.3.4 "Der Aufstieg der Familie Fugger" (The rise of the Fugger family), subsection (c) "Stadtluft macht Frei" (The air of the city sets you free): > > *Die Vorfahren von Jakob dem Reichen (1459-1525) waren keine unternehmerischen Genies, aber sie waren allesamt reichlich zäh. Hans Fugger hatte erkannt, dass er als Landweber auf dem Dorf keine allzu großen Zukunftschancen besaß. Die Landweber waren vollkommen abhängig von den Kaufleuten der Stadt, welche ihnen di e Rohwaren brachten und die fertigen Stoffe wieder mitnahmen. Landweber wurden schlecht entlohnt — pro Tag verdienten sie etwa zehn Kreuzer. Das machte einen Gulden in der Woche und fünfzig Gulden im Jahr — vorausgesetzt, es war genug Arbeit da. Die Weber in der Stadt verdienten mehr, und das war einer der Gründe, weshalb die Augsburger Verlagsherren, wie man die entsprechenden Kaufleute nannte, lieber die bescheidenen Dörfler beschäftigten. Gewoben wurde auf einfachen Webstühlen, das Produkt war vornehmlich der Barchent, ein fester, auf einer Seite aufgerauhter Stoff aus Baumwolle und Flachs. Er wurde zu den groben Kleidern der Bauern und Bürger verarbeitet, wohlhabende Kaufleute und der Adel dagegen bevorzugten Seidenstoffe und Damast.* > > > which means > > The ancestors of Jakob the Rich (1459-1525) were not entrepreneurial geniuses, but they were all pretty tough. Hans Fugger had realized that as a *country weaver* [*"Landweber"*] in the village he had no great future prospects. The *country weavers* were completely dependent on the merchants of the city, who brought them the raw materials and took back the finished fabrics. *Country weavers* were poorly paid—they earned about ten [kreutzers](https://en.wikipedia.org/wiki/Kreuzer) a day. That made a guilder a week and fifty guilders a year—assuming there was enough work. The weavers in the city earned more, and that was one of the reasons why the Augsburg distributors [*"Verlagsherren"*, literally master shifters], as those [specialized] merchants were called, preferred to employ the humble villagers. Woven on simple looms, the product was primarily [fustian](https://en.wikipedia.org/wiki/Fustian), a solid fabric made of cotton and flax, [piled](https://en.wikipedia.org/wiki/Pile_(textile)) on one side. It was made into the coarse robes of peasants and citizens, while wealthy merchants and the nobility favored silk and [damask](https://en.wikipedia.org/wiki/Damask). *(Translation based on Google Translate, corrected and improved by hand.)* > > > [Answer] ## Demand a ~~hostage~~ ward as collateral A good collateral is a family member of the monarch. Someone young and closely-related to the king, yet not important enough that they want them at their court. Like the 2nd daughter, the 5th son, a niece or nephew. Not as a hostage, of course. They would be entrusted to you as a ward. You would provide them with an education in the arts of business, economy and negotiation to prepare them for their future challenges as a noble. You would also provide them with a standard of living which suits their position. They will just become a hostage if the king stops fulfilling his side of the bargain. This was actually a very common practice between nobles in the middle ages. When you wanted to form a trust relationship with another noble, you would send them a close family member as a ward. Officially this was to provide the family member with a wider education and to give them the opportunity to form connections with other powerful people. But inofficially it was often to provide the educating party with an insurance against getting double-crossed. A step further is to arrange a marriage between your families. Forming marriage ties implied a permanent alliance between the heads of the families. But when your family does not have a noble heritage, the king would be very reluctant to let you marry into the royal family. [Answer] # Don't supply gold, supply troops. One option, apart from AlexP's excellent answer, is to avoid supplying any gold directly to the autocrat. In your case, the autocrat wants to spend the gold, borrowed from you, convincing a number of lords to join his quest. So perhaps you could buy those lords directly instead? "My Lord, it would be highly lucrative for you to supply troops to the King in the coming war. If you so wish, I can lend you the gold to set up an army." (Or hire mercenaries) If all goes well, the King won't be in debt to you directly, but to several lords/vassals. Ignoring them might be more dangerous than going after you. And if one of those lords refuse to pay... well hopefully you have the autocrat on your side there. In short, spread your risk by supplying troops through intermediarys instead of lending directly to the autocrat. [Answer] ## 1. Religious Loans Your bank should be part of a religious institution that the King and most of his subjects also worship. Historically, the Catholic Church was one of the largest loan and debt-collecting organisations, using excommunication as a potent tool for forcing repayments. It would be a foolish or desperate King that would risk religious unrest to avoid paying their dues. Of course, there were no end of foolish and desperate monarchs in history, so this is still no guarantee. ## 2. Military Force As a bank, you can make loans to mercenary troops, keeping a large military force in reserve. Mercenaries in medieval times were usually veteran and experienced troops, especially Swiss and Italian companies. Compared to royal and noble levies, you would have a superior local force. Wait until the King is embroiled in his foreign war, then demand repayment from seized foreign assets and loot. You have the local superiority then, and the King will risk military turmoil if they don't meet your demands. You could seize local assets if your demands are still refused. ## 3. Political Influence Having loaned foreign royalty and nobility money at reasonable rates, you have built up political capital and goodwill with other nations. You can use this to subtly pressure the King. Will you throw your political weight around to create an alliance against this kingdom if he fails to repay? Once he's involved in a foreign war, this is a real, credible threat. This is the riskiest option because it requires you to have faced similar issues with other monarchs previously, but once you have that influence, future loans become far easier to recoup. [Answer] You can't - it's simply impossible to guarantee. Who are the people going to believe, the word of their king or the word of their banker? The king has no reason to ask you for a loan either, he could just straight up confiscate your assets for personal use the moment he finds out about you. Being an Autocrat, the king could also simply produce more currency, thus causing inflation, and your assets to be worth less. He can steal from you, and everyone else in his country, without actually stealing from you. Unless you have a king that you 100% trust, there's no reason for you to even try this. Mark my words - **It will end badly.** Here are your possible solutions: ### THE INVESTMENT METHOD Go to the Kings shop and find something you can "invest" in. Eg: Buy up jewelry and gems, in the hopes that the king will eventually buy them back from you. Basically create a stock market type transaction where you buy units of XYZ and give the king fiat (which he needs), then when he's done with it, you'll be able to sell the units of XYZ hopefully at a profit. If you picked gemstones and the like, the value of those aren't likely to go down by too much, or are likely to go up depending on the land and the story. ### THE "THE ENEMIES OF MY ENEMY ARE MY FRIENDS" METHOD If you have enough resources to lend to the king for the king to dominate the neighboring countries, stage a coup. Go to the king of the neighboring country, tell him you'll pay him to help you take over your country. You'd get the help of more than a few lords, as there are many benefits to having a friendly country beside you. Expose your kings plan to them, make sure they know that you can coexist and don't have to go to war, propose favorable trade agreements for when you're the king. There are a multitude of things you can do that can help you secure your own kingship, and once you have your own kingship, you can easily increase your own wealth. In fact, when you're the king, you can actually lend out money to increase your wealth since you'll have knights to help you dish out punishment against those who don't pay up. [Answer] Why not do what banks and big business actually do? Buy politicians on their way up, own them forever. Back them **and** their rivals, produce a scandal when needed, or destabilize a corporation, let one of the alternates take over. The autocrat may have "absolute power" but there will be rebels and a 5th column for the bank to fund, or the bank can - clandestinely - back the other side in a war, and failing that there are always tragic accidents and assassinations. For non-real world examples of this you have [Iron Bank of Braavos](http://gameofthrones.wikia.com/wiki/Iron_Bank_of_Braavos) (SoIaF) and [Valint & Balk](http://firstlaw.wikia.com/wiki/Valint_%26_Balk) (The first law) NB: The important thing to note, is the bank doesn't wait to act, the bank is constantly in operation with plans B to Z ready to go in case plan A goes awry. [Answer] **Invest in the enterprise.** If you issue a loan, you are not an ally - you are a businessman and could be considered an adversary. An investor, however, wins or loses with the endeavor in question. An unsuccessful endeavor means the money is lost. A successful endeavor however means you will be there for him next time too. Make clear to the king you support his military endeavor, and in the (in your opinion, likely! Say it loud!) event of victory, your interest in return is in presiding over lands x and y - and paying taxes from this income to your king as you always have, of course. You have skin in the game now and your fortune rides on the fortune of the king. *Which is already the case* as you point out - you are based in his country and are at his mercy. Moneyed persons with options might have opted at some previous time to move their resources and base of operations to a more predictable locale than the one you are in - for example Russian oligarchs parking money in Cyprus or the recently leaked [Panama papers](https://en.wikipedia.org/wiki/Panama_Papers), or the [Iron Bank of Braavos](http://gameofthrones.wikia.com/wiki/Iron_Bank_of_Braavos) in Game of Thrones. But you did not do that. No, you are right there with this aggressive monarch and your fortunes are tied to his anyway. You might as well back his endeavor. And while he is busy, hedge your bet with a quiet move of at least some of your resources to some friendly nearby locale. [Answer] Let's start with a simple economic fact : No loan is risk free. > > What measures can I take to insure that the King will not just decide that he owes too much money to me and confiscate it all ? > > > Sell the business to someone else. Not joking - that's the only strategy that is 100% safe from this risk. > > I would prefer: > > > If you're King, prefer matters. You're not. :-) > > No eventual execution on false charges, banishment, or impoverishment. > > > Flexible interest rates, favorable terms. Lots of "as your majesty wishes". > > Eventually regaining my lent money plus interest, or something else of equivalent great value > > > Being able to borrow has to have greater appeal that stealing your money. This is simply a matter of common sense for most rulers, as if he screws over the loyal (you are loyal, right ?) help of a subject, who will help voluntarily, volunteers will start to become hard to find. More importantly people will move their money and themselves out of his control. Having to force everyone to help you sound fun, except that eventually that's how monarchs end up as deposed monarchs and the sensible ones don't risk this. But to lend to monarchs you do have to accept that they will pay you back on *their* terms. You might get leverage from this, favorable terms on some other deal you want to do, but you won't get to guarantee anything. Interest from your own King to finance this patriotic endeavor is entirely optional from your point of view, just as applying thumbscrews to parts of your body other than your thumbs is entirely optional for your King. The expression we're looking for here is "happy to help, your Highness, interest free goes without saying.". If you're very, very lucky, you might get a title other than "victim" out of it. > > (Optional) A maintenance of (at least outward) neutrality so that I can also lend to my king's enemies > > > Did I mention being a *loyal* subject ? Let's remember this : > > The ruler of the country I'm based in has his own wishes: he wants to conquer the neighboring country, paying off some lords over there to join his side. > > > You do not get to be neutral if you want to be loyal and being loyal is not an optional extra. Lending money to your own King's enemies is called being a traitor. If you're lucky you'd get a reasonably quick death, although that's not my idea of being a vengeful autocratic monarch. So unless you're not only suicidal but also masochistic, I'd suggest lending to the King's enemies is not a plan any responsible CEO would endorse. [Answer] I am currently reading the book [Why Nations Fail](https://en.wikipedia.org/wiki/Why_Nations_Fail). There the author makes a point that economic development is closely linked with politics. You came to the same conclusion, as you (the banker) do not trust the (absolute) monarch. To loosely quote from the book, this is a common theme in all extractive political systems (a minority has much or all the political power). Such political systems are very likely to also have extractive economic systems (a minority controls the economy and reaps its profits). In your case, to secure points 1 and 2, become allied to the king. Thus, join the elite of the extractive economy. The elite will always look after itself. That covers 1 and 2. If you want to have all 3 points, then you need some sort of inclusive economy (people are free to start businesses, there are low entry barriers, and there are secure property rights) in an extractive political system, which is deemed by the author as stable only in rare cases. In essence, a scenario of modern day China would allow your banker to cover point 1-3. You have an absolute ruler, who interferes relatively little with the economy, as well a largely inclusive economy that does not threaten the ruling political elite. Sorry for butchering the book's theories, however, I strongly suggest it if you are into politics, and are interested to explore why the world is, as it is now. [Answer] ## Money is power Both countries and armies run on money. No money, no army. No army, no country. Several answers have stated that you should give up on the idea of loaning money to several competing monarchs. I would like to go the other way and say that **the key to success is having several monarchs and other powerful people in your debt.** Make sure that your holdings are spread out in many countries so that no single monarch can confiscate more than a fraction of it. Have a big family and have it spread out too, so that an attack against one family member can be avenged by the others. Make sure your debtors *know* that the debt doesn't disappear with your death, but will be collected by the family. Any confiscated property will also be added to the debt. Scare merchants away from the bad debtor by saying that any merchant who trades with them becomes responsible for their debt too. Without trade the country/monarch is *really* bad off. You may lose a few family members and have to make an example of a few monarchs before the rest gets the point. [Answer] At this point it would depend entirelly on the Autocrat, if he feels like paying you then he will, otherwise... I'm sure future historians will have a fun time readying about your death. If you have enough money you could hide something away and put it as a bounty against the King in case he ever betray you, but even them it assumes there is some bigger fish that could deal with this King in the first place. [Answer] Make sure that you never lend them *all* of your money. All but the most foolish of autocrats will have plans beyond just this one, upcoming war. Make it quite clear that if they prove a trustworthy debtor and make regular payments, then you have an incentive to protect your "investment", likely by lending them additional money in the future. If they default on their loans however, then you'll have absolutely no reason not to lend money to their enemies as a way to recoup your losses. Play it right and you can have most of the major powers practically competing for who can borrow the most money from you, because they know you'll want to protect your largest investment the most. Cheerfully let them pay just the interest on their debts and you can rack up massive amounts of money over the subsequent generations. Use this money to covertly diversify into the arms trade and make sure to sell weapons to both sides of every conflict. Your goal is to get them both to rack up as much debt as possible and end in a stalemate so that you get to keep *both* accounts. This won't always work of course, but it really doesn't need to. You can always foment an uprising in the name of the old government if necessary. Within a few generations your bank should be the secret power behind the throne of most major players in whatever portion of the world you choose to make your domain. Kingdoms can rise and fall all they want, but as long as you stay out of the public eye and content yourself with simply being filthy rich but not particularly famous there won't be any concerted effort to take you out. Except maybe by other banks... Fun fact: Britain is *still* paying interest on its debts from the French and Indian War in the early 1700s. [Answer] How about collateral? Does the Autocrat have anything he holds as dear as his desire for conquest? If yes, demand to hold it on your terms until he squares his loan. Think about what you will accept and your terms carefully: You have to be able to possess, physically, whatever it is he does not want to lose, and you must be able to possess it in such a way that any "accident" you meet would result in him losing it forever. [Answer] Divide a fund into several subsidiaries and command them to lend a total amount to the king. The king will target the subsidiaries to delete unpaid debts, and only a subset of them. Another obvious option is to allow the king to mint more money. The interest paid would be new money, but you would raise rates to drain the new supply. (which is precisely what the new Fed chairman is doing this year, for all you mortgage payers out there) The other answer about the Fuggers basically says 'use your wealth to establish political influence'. An option. I would probably go for an economic attack on the foreign country: Create trade imbalances by selling cheaply to the foreign country. This can be achieved through domestic economic manipulation. Trade deficit settlement is carried out by gold shipments. This eventually leads to raised interest rates and contracting cash supplies in the target economy. Bribe the target officials and lords by paying in their weak foreign currency, which is also earning higher rates. No lending to king necessary, only in nominal terms. [Answer] Might i offer another solution that may guarantee a return on your loan but only if said sovereign has unwed children of age. i would suggest to marry into the family and then your loan becomes an investment in your own future especially if your spouse is next in line for the throne and is loved by their father. a further guarantee would be to supply the sovereign with a grandchild to keep the blood line going. [Answer] 1. **Diversify the assets backing the loan** Get the King to agree to a mix of (A) fixed assets (i.e. land inside the Kingdom (B) Foreign assets - land/gold jewels already held in foreign locations or moved there as guarantee for at least partial payback. (And keep the deeds etc outside the country.) (C) A share of the spoils if he wins. 2. **Diversify the risk**. Even if you can afford to lend him the entire amount he wants say you can't and put together a pool of bankers so that your competitors also have to bear a portion of the debt. If he loses the battle this also 'diversifies' his anger at having to pay back his loans. 3. **Lend at generously low rates** in exchange for access to certain guaranteed income streams like liens over a % of certain royal tax revenues for a fixed period of time - so that at least part of the loan is covered. The King is less likely to miss what he doesn't get in the first place and can always raise taxes to adjust. 4. **Be invaluable in other ways** - provide financial services for the King and his chief ministers/ agents. Efficiently transfer funds on their behalf, provide advice on investments. Let them in on good deals you are investing in but don't let them invest too much in any one deal in case that deal goes south - or pay them back if it does and wear the loss, at least for 'smaller' debts. In short get in good as you can with at least some of the King's closest advisers so they can, at times cover you back. (If they owe you, they owe you) 5. **Pass on the odd bit of useful intelligence** you get through your banking and trading networks. (But not so much and so regulatory that they begin to regards you as 'their spy'. 6. **Have a lot if not most of your personal assets spread around other countries** not just the one you live in. And own a fast horse in case things go wrong. ]
[Question] [ As is well known, all of Santa's presents are manufactured by elves at the North Pole. However, a lot of presents are protected by various IP rights. Be it Adidas clothing, a DVD of the newest Blockbuster or the newest iPhone, Santa obviously constantly violates trademarks, copyright and patents. Surely the big rights holders corporations are all but happy about this. Yet no lawsuit against Santa has been brought forward till now. So how does Santa manage not to get constantly sued? [Answer] There are several options to resolve this paradox: * He is getting sued all the time, it's just that nobody wants to make a big PR deal about this. Imagine the damage to your brand if it became known that you are suing Santa, of all people. * He is getting sued all the time, he just doesn't care. He can continue his shady business unabashed year after year because really, how would anyone stop him, what with his army of elves and magical sled, all located on the North Pole, among the least hospitable places on the surface of Earth? * He's not actually getting sued because he has dutifully acquired, where necessary, a license for each and every article he manufactures. * His workshop full of "elves" is actually a typical Chinese/SE-Asian sweatshop employing child labour, so no license is required. Since his workers toil away under precarious conditions (housing, milk, and cookies), and Santa takes care of all the logistics with his magical sled, his price per unit of merchandise is unbeatably low, practically free. * Blackmail: He counters every subpoena and legal charge by threatening to put everyone involved *and their children* on the Naughty List. Who in their right mind wants to risk getting on Santa's bad side? [Answer] It's fairly simple really, patent and copyright only apply within the borders of a country in which the product is registered. There are various international systems but no universal treaty. Since Santa is manufacturing outside an area where these treaties apply, he's not bound by copy protection laws. Since he's not selling the items, they can't be taken off the shelves. He's clear and free. [Answer] I'm not supposed to reveal any of this due to NDA, so don't tell anywhere where you heard this: Santa has no IP problems due to secret compulsory license treaties that date back centuries -- manufacturers have to grant a free license to Santa to manufacture toys, in return, Santa contributes to the media blitz that causes the marketing frenzy every holiday season (for example, Santa and his elves spend weeks every December making unpaid promotional appearances at malls, plus he has a huge staff of elves reading letters from children). Most gifts are bought by people to give to their loved ones, so Santa's manufacturing center doesn't eat too much into corporate profits, so it really is a win-win. If it seems that Christmas spirit has been lacking in recent years, Santa has been busy trying to hammer out a global climate change accord to keep his North Pole headquarters from sinking into the ocean when the polar ice cap melts. He's not hopeful that will happen, so he's been working on a relocation plan to move his headquarters to the south pole. A migration of this scale will take him years, so there will be a gap in Santa's gift giving while he relocates his toy factory. During the interim period, he'll be delivering coal in lieu of toys. Santa has been buying up stocks of coal to prepare for this, and ironically, even as he fights to stop global warming, Santa owns the world's largest stockpile of coal. [Answer] Santa has a very dark side that people don't like to think / talk about. He has an army of elves that most people think of as cute little warehouse workers that manufacture and pack presents - which they do. During the year, however, they don't have much present-related work to do: how do you think they utilize all that free time? They travel around the globe and defuse all kinds of legal threats that Santa receives for his shady practices. Just look what happened to Volkswagen after they foolishly tried to hit Santa with legal action: all their own shady practices came to light. All it took was a few little elves with hacking tools (which they manufacture for gifting purposes). When a company doesn't learn from hints like that, the elves start to play hard - they do make guns and ammunition, after all. [Answer] I'm sure someone has tried, but they would run into multiple problems in short order. 1) How do you prove he's making them? They're exact duplicates, after all. Even if you trace serial numbers, you'll find that they're in your system as authentic. 2) Where do you serve him? He's not a resident of your country, and if there's a government at the North Pole, they don't have treaties with anyone (and if there's a boss, it's probably the Big Man himself) 3) Better yet, *how* do you serve him? Not like anyone's gonna catch him during his yearly trip (heaven knows NORAD has been after him for years with no success), and your GPS ain't gonna get you to the Workshop. 4) I suppose you could try him in absentia, but what country wants to admit that a foreign national does millions of home invasions every year and the government is powerless to stop it? [Answer] Companies routinely build corporate relationships with overseas manufacturers to create product and lower manufacturing costs. It could be postulated that out of all of the products created, North Pole manufacturing actually takes up a LARGER than expected percentage of overall production, done almost completely in secret. All involved parties have signed the appropriate NDAs, which is why you hear almost nothing of this until the Holiday season when North Pole shipping lanes become extremely active, moving product to various distributors throughout the world. This information is almost completely obliterated in obscurity, as any individual who might see a legitimate "sleigh run" would be sure to attribute such a sighting to decorations or an over-active imagination. Of course, Santa's cheap labor, uncontested natural resources, and leveraging of advanced technology (a sleigh with the speed to travel to millions of homes in one night without turning the passenger into a pancake?) gives vendors unrivaled access to fast, cheap manufacturing. And Santa's payment? He gets a fat cut of his choice of merchandise, based on letters coming into the North Pole. (Obviously, there are more requests for Xbox game systems for Christmas than hydraulic pump filters.) Lastly, Santa knows the incredible value of "playing nice". Santa knows that companies need to sell product to survive, thrive, and benefit the world economies. It's not his intent to give every child everything they could possibly want, because to make their Christmas that amazing, the loss of income (where parents normally go out and BUY those gifts) might make someone else's Christmas not so nice. If I had to guess (and I am obviously guessing), I would say the big guy in the red suit is more concerned with everyone getting along (as much as possible) than the accumulation of stuff. As long as enough people in leadership of the corporate world remember that, Santa and the big C's will have many years of peaceful, lawsuit-free cooperation to come. [Answer] No one here understands. Santa is serving his time at the north pole for burglary. Christmas is his once a year parole. [Answer] A lot of kids might think that they are on the nice list, but in reality [very few actually make the list](https://worldbuilding.stackexchange.com/questions/13495/how-can-santa-exist-when-adults-buy-the-toys/13521#13521). If so, corporations might not even notice the few extra copies of their stuff floating around out there. Even if they did notice, companies might just write it off as advertising or other promotional expense. And simply invoking Santa's image helps them sell their goods to the parents of the other 99% kids not on the "nice" list. [Answer] It's like Netflix, BMG, and Columbia House -- they license the right to manufacture nearly indistinguishable copies of the retail version. (Things that you ask for that Santa doesn't provide are obviously the result of licensing-negotiation breakdowns. Consider also the time you asked for a Transformer and got a Go-Bot...) [Answer] Luckily, the answer to this, while ostensibly very secret, showed up recently in WikiLeaks. As you know, Santa is the benevolent and immortal ruler/god of an isolated nation of elves. They flout the received wisdom of globalization - they have achieved high industrial output despite complete isolation from the world economy. Noteworthy is the complete lack of forex trading in Donders (or even [this](http://www.masshist.org/objects/cabinet/december2001/december2001.html)), along with an absence of North Pole investments in emerging market funds. When you add this to the nimbleness and robustness of elves, and the extraordinary ability to monitor the entire world population (under the rational of determining whether the observed is denoted 'naughty' or 'nice') with either sophisticated surveillance devices or even clairvoyance, the conclusion is inescapable: Santa could easily crush any nation state he wished. Heck, with all the surveillance, can you imagine what dirt he has on all national and corporate leaders? And what do you think elvish engineers and factory workers do once the Christmas stockpile is finished? They build weapon systems. For instance, the Intercontinental Ballistic Mistletoe alone surpasses anything in our arsenal. Yes, there have been a few clandestine attempts at 'regime change' by the usual suspects, but all have failed and, until the WiliLeak, been covered up. Now the nations of the world and the leaders of multinational corporations have the tacit agreement that Santa must be deferred to. Hence, the fact that no IP suits have been brought against Santa is not a surprise at all. Frankly, we should fear the day that Santa croaks (perhaps due to a freak sleigh/jet collision)- he may be replaced with an elf with a less benevolent disposition. World domination would follow swiftly. Yule be sorry then. [Answer] No-one ever sends him a threatening letter because they are worried he might remove their children from his Christmas list. [Answer] You're working under the misapprehension that Santa actually manufactures gifts every year -- apart from the occasional handmade toys (usually gifted to the children of woodworkers and metalworkers, weirdly enough), most of Santa's goods are purchased from their original manufacturers and then gifted for free to children around the world. In fact, he purchases so many goods that [winter holiday spending can be 6-10 times larger than spending at any other time of the year](https://nrf.com/news/the-long-and-short-of-americas-consumer-holidays). Some people have even suggested that Santa has hung up the sleigh, purchasing gifts through a complex series of intermediaries and shell companies and then shipping them through modern logistic channels (in which local toy stores play a crucial but unclear role), but others have correctly pointed out that such an approach would require a **ludicrously** massive conspiracy in which as many as one-third of the population would need to work secretly with Santa for decades without a single whistleblower ever revealing the scheme to the press, government or general populace. Even the Stasi only managed to recruit [around 2.5% of the population](https://en.wikipedia.org/wiki/Stasi#Personnel_and_recruitment), so a global conspiracy of this scale seems to simply be unmanageable and should not be taken seriously. [Answer] The corporations don't know (or cannot prove) that their licenses are being violated. They know how many units of each product were manufactured, and they know how many were sold. But there is no way to measure how many products are actually in the hands of customers and/or children. Also, since all of the unlicensed products were received as gifts, the corporations cannot even ask each product-owner to show a valid sales receipt. [Answer] There are few options 1. Nobody knows exactly where he lives, hence it is hard to deliver lawsuit. 2. Santa knows everything what every person did wrong, and can blackmail company owners and lawyers to not pursuing lawsuit. 3. Santa's actually have only R&D department in North Pole, and manufacturers are his subsidiary companies. So iPhone was actually designed by elves, and then was passed to Apple to made marketing. It is obvious Steve Jobs was an elf, how you could explain fact he was earning only one dollar for running company? [Answer] If you sue Santa, you can expect much worse counter- suits from him, or more specifically, Mrs Claus. She does business under her maiden name since she engineered the whole arctic toy factory. Perhaps you've heard of the world's greatest inventor, Patricia "Pat" Pending? [Answer] I firmly believe that "North Pole" is just an euphemism, we as human went over and over there and we just cannot found a single evidence that someone was ever there, not even a elf's scarf that could a elf drop during a strong storm. And even if you think further, someone who can travel the world in a day should not be limited to this world. Is mathematically possibly that in many other planets in the Universe or Multiverse that have their own Christmas and Santa is also in charge of the gift delivery. I also have a theory that Santa is helping evolve races in the universe through gifts helping children raise their imagination but is not related to the question. What I'm trying to say is that Santa is not in the Earth so that's why cannot be located or sued. [Answer] Has anyone done the research to see who exactly wants to sue Santa? The idea occurred to me quite possibly it was the coal company's what do you get when your bad?? And well, as the the saying goes,if life gives you lemons... Perhaps if Santa give you coal make a million bucks? Just a thought [Answer] **Bribery** Sure, you could sue Santa...or you could look the other way this time and maybe there's a new jetski in your driveway on Christmas. üòâ **Settlements** Settlements are really just above-the-board bribery. **Counterfeiting** This assumes the court allows payments to be made in cash. His toy factory can make more complicated things than bills, after all. [Answer] Only 'naughty' lawyers would try to sue Santa and since *all* lawyers care about their public reputations no one does. [Answer] ## Relativistic sled ride related time travel Santa can only visit all the children by using his FTL drive. It takes him back a little in time upon each use. When people sue him for IP reasons, they....never did. They just all didn't turn out that way, or chose differently. I sure hope the methods he uses are nice and not naughty. [Answer] **He buys them.** The elves specialize in the stuff that can't be mass produced. For that which can, Santa Claus buys them using the money he gets by licensing his own image. There may be contracts in place where he's played in kind by toy companies but I'm not privy to them. Alternatively, he licenses his images and uses the license money to buy licenses to manufacture the toys. ]
[Question] [ We are occasionally asked for advice about the worldbuilding process. By its creative and imaginative nature, the process of worldbuilding doesn't have a single obvious starting point or a step-by-step process that is universally applicable to all worldbuilding efforts. The answer below lists many worldbuilding resources that can help you with your, "where do I go next?" questions. We recommend that you review these resources before asking us, so that if you do need to ask, you know *exactly* what problem you need to solve. Please note that there are many specific questions assigned the [worldbuilding-process](/questions/tagged/worldbuilding-process "show questions tagged 'worldbuilding-process'") and [worldbuilding-resources](/questions/tagged/worldbuilding-resources "show questions tagged 'worldbuilding-resources'") tags. Most of them are too specific to be generally useful for the purpose of this post. We recommend reviewing them both for their content and to get an idea of the kinds of specific resource and process questions we answer here. The answer has been created as a community wiki, which means everyone is invited to add resources. I and the moderators reserve the right to remove entries that we deem trivial or inappropriate. Everyone is welcome to help with formatting to keep the list neat and organized. 1. If you have questions, please post them as a comment to this question. When addressed, please delete the comment. 2. Please *DO NOT* post additional answers to this question. Answers other than the community wiki will be arbitrarily deleted. 3. If your entry can reasonably be listed under an existing header, please do so. Create new headers only when absolutely necessary. 4. Your entry must link to the resource (no non-link entries). > > **Clarification:** Due to James' query about whether or not it makes sense for this question to exist here on Main, I opened a [Meta discussion asking why it shouldn't exist on Main](https://worldbuilding.meta.stackexchange.com/q/7273/40609). The post on Meta is NOT identical to this post. My personal belief is that this question belongs on Main. > > > [Answer] **Worldbuilding Lexicon** * [What is a LitRPG?](https://worldbuilding.meta.stackexchange.com/a/9877/37029) **A Word about Copyright** * [How does using Worldbuilding.SE affect my copyright?](https://law.stackexchange.com/a/77923/12916) * [When is a person a co-author of a joint work?](https://law.stackexchange.com/q/78024/12916) **General Guides** * [Universe Factory](https://medium.com/universe-factory): [Some theoretical considerations to world building methods](https://medium.com/universe-factory/some-theoretical-considerations-to-world-building-methods-7bfafe2870b) * A short guide to worldbuilding - [Part 1](https://www.reddit.com/r/worldbuilding/comments/6k4bjc/a_short_guide_to_worldbuilding_part_1/), [Part 2](https://www.reddit.com/r/worldbuilding/comments/6k9qzc/a_short_guide_to_worldbuilding_part_2/), [Part 3](https://www.reddit.com/r/worldbuilding/comments/6koud8/a_short_guide_to_worldbuilding_part_3_final/) * Roll for Fantasy worldbuilding guide - [Part 1](https://rollforfantasy.com/guides/world-building.php), [Part 2](https://rollforfantasy.com/guides/world-building-part-two.php), [Part 3](https://rollforfantasy.com/guides/world-building-part-three.php) * [Ultimate worldbuilding guide for writers](https://hilbertthm90.wordpress.com/2019/01/18/how-start-worldbuilding-writers/) * [Guide To World-Building: How To Write Fantasy, Sci-Fi And Real-Life Worlds](https://writersedit.com/fiction-writing/the-ultimate-guide-to-world-building-how-to-write-fantasy-sci-fi-and-real-life-worlds/) * [Short Primer of the Making of Invented Cultures](https://cbbforum.com/viewtopic.php?f=29&t=5618&p=233357&hilit=primer#p233357) * [The Great Ethnographical Questionnaire](http://www.bethisad.com/questionnaire.htm) * [Workshop on Villain Creation](http://www.giantitp.com/articles/rTKEivnsYuZrh94H1Sn.html) * [Lymyaael's Literary Rants](https://curiosityquills.com/limyaael/) * [30 Days of Worldbuilding](http://www.web-writer.net/fantasy/days/) * [Orion's Arm Resources](https://www.orionsarm.com/xcms.php?r=oa-page&page=gen_worldbuilding_links) **The First Step** * [Is there a "best" way to start worldbuilding?](https://worldbuilding.stackexchange.com/questions/42696/is-there-a-best-way-to-start-worldbuilding) * [The Rules of Quick and Dirty Worldbuilding](https://io9.gizmodo.com/the-rules-of-quick-and-dirty-worldbuilding-5039477) * [Worldbuilding Pillars](https://worldbuilding.stackexchange.com/questions/112851/in-order-to-build-a-fantasy-world-what-basic-pillars-are-needed/112859#112859) * [How can I break down the task of creating a world into manageable chunks?](https://worldbuilding.stackexchange.com/q/2/40609) * [Worldbuilding Questionnaire #1](https://docs.google.com/file/d/0BxfxDe6Ap7_mMGxhNVhTSHBLZWM/edit?pli=1) * [Worldbuilding Questionnaire #2](https://www.sfwa.org/2009/08/04/fantasy-worldbuilding-questions/) * [Fantasy Worldbuilding](http://www.web-writer.net/fantasy/) * [Setting the Fantastic in the Everyday World](https://www.writing-world.com/sf/contemporary.shtml) **The Last Step** * [How to know when I'm done?](https://medium.com/universe-factory/good-enough-how-to-know-when-you-re-done-7df1a16fedac) **Celestial Mechanics** * [Creating a realistic world(s) map - Stars](https://worldbuilding.stackexchange.com/questions/23040/creating-a-realistic-worlds-map-stars?lq=1) * [Creating a realistic world(s) map - planetary systems](https://worldbuilding.stackexchange.com/questions/21408/creating-a-realistic-worlds-map-solar-systems?lq=1) * [Building the ultimate solar system](https://planetplanet.net/the-ultimate-solar-system/) * [Sol Station Local Star Charts](http://www.solstation.com/#sthash.JG9BtjcG.dpbs) * [3D Star Maps (Project Rho)](http://www.projectrho.com/public_html/starmaps/index.php) * [Orbit height and speed calculator](https://www.satsig.net/orbit-research/orbit-height-and-speed.htm) * [Orbital Velocity Calculator](https://www.omnicalculator.com/physics/orbital-velocity) - allows you to easily calculate most of a planet's orbital characteristics, including eccentricity, semi-major and semi-minor axes, velocity at periapsis and apoapsis, orbital period etc. Input the information that you know or want and the calculator figures out the rest. **Religion & Philosophy** * [Creating a realistic world - Spreading religions](https://worldbuilding.stackexchange.com/questions/25478/creating-a-realistic-world-spreading-religions) * [Fantasy Religion Design Guide](http://inkwellideas.com/worldbuilding/worldbuilding-religion-design/) * [Fantasy Religion Questionnaire](https://www.deviantart.com/themusessong/art/Fantasy-Religion-Questionaire-353760571) * Roll for Fantasy - Religion Creation - [Part 1](https://rollforfantasy.com/guides/religion-creation.php), [Part 2](https://rollforfantasy.com/guides/religion-creation-part-two.php), [Part 3](https://rollforfantasy.com/guides/religion-creation-part-three.php) * [A Collection of Mythology Building Resources](https://referenceforwriters.tumblr.com/post/53049866924/masterlist-original-gods-and-goddesses) * [Creating Religions and Belief Systems](https://mythcreants.com/blog/creating-religions-belief-systems/) * [Creating Fictional Holidays](http://fmwriters.com/Visionback/issue6/Creatingfictional.htm) * [Mythic Scribes Worldbuilding Resources](https://mythicscribes.com/category/world-building/) * [Internet Sacred Text Archive](https://www.sacred-texts.com/) * [Encyclopedia Mythica](https://pantheon.org/) **Mapping** * [Creating a realistic world map - Landmass formation](https://worldbuilding.stackexchange.com/questions/581/creating-a-realistic-world-map-landmass-formation) * [Creating a realistic world map - Erosion](https://worldbuilding.stackexchange.com/questions/1020/creating-a-realistic-world-map-erosion?lq=1) * [Creating a realistic world map - Coastlines](https://worldbuilding.stackexchange.com/questions/21349/creating-a-realistic-world-map-coastlines?lq=1) * [Creating a realistic world map - Waterways](https://worldbuilding.stackexchange.com/questions/21402/creating-a-realistic-world-map-waterways?lq=1) * [Creating a realistic world map - Underwater geography](https://worldbuilding.stackexchange.com/questions/23097/creating-a-realistic-world-map-underwater-geography) * [What tool can I use to draw a simple map of a fictional world?](https://worldbuilding.stackexchange.com/questions/8896/what-tool-can-i-use-to-draw-a-simple-map-of-a-fictional-world) * [Anyone know of a good software for making a galaxy map?](https://worldbuilding.stackexchange.com/q/125641/40609) * [GoCAD](http://www.geo.tu-freiberg.de/%7Eapelm/gocad.htm) 3D Geomodeling * [QGIS](https://qgis.org/en/site/) Open-source geographic information system * [Build Your Own Earth](http://www.buildyourownearth.com/) * [Map Maker 4](https://www.mapmaker.com/) * [Azgaar's Fantasy Map Generator](https://azgaar.github.io/Fantasy-Map-Generator/) ([older version here](http://bl.ocks.org/Azgaar/b845ce22ea68090d43a4ecfb914f51bd)) * [Planet Maker](http://planetmaker.wthr.us/#) * [Celestia](https://celestia.space/index.html) * [Space Engine](http://spaceengine.org/) * Texture: [CrazyBump](https://www.crazybump.com/) * Texture: [ShaderMap](https://shadermap.com/home/) * DonJon's [System Generator](https://donjon.bin.sh/scifi/system/) * DonJon's [World Map Generator](https://donjon.bin.sh/scifi/world/) * DonJon's [Fantasy Map Generator](https://donjon.bin.sh/fantasy/world/) * [Planet Map Generator](https://topps.diku.dk/torbenm/maps.msp) * [Cartography, Maps, Star Charts, and Writing](https://thewritingbug.tumblr.com/post/30846898623/cartography-maps-star-charts-and-writing) * [Decorative Map Making](http://www.decorative-maps.com/) * Martin O'Leary - [Generating fantasy maps](http://mewo2.com/notes/terrain/) * [Earth Political Border Map Maker](https://yulin-w.github.io/alternate-history-editor/main.html) * NBOS Software's [Astrosynthesis Star Mapping Sofware](https://www.nbos.com/products/astrosynthesis/) AstroSynthesis can map out large portions of space - plotting stars, interstellar routes, and sub-sectors. Zoom in and out of your sector, pan and rotate around stars, follow routes, complete with animation effects - all in 3D space. The built-in generator can also generate detailed solar system information for each star system: planets , their moons, asteroid belts, and other types of bodies. Generate extended planetary data - atmospheres, surface gravity, temperature, and more. The NBOS site claims that it applies scientific principles during generation, taking into consideration matters of astronomy, physics, atmospheric chemistry, and planetary sciences during the generation process. **Climate & Weather** * [Worldbuilding & Climate: How does the sun affect a simple sphere with atmosphere?](https://worldbuilding.stackexchange.com/q/103694/40609) * [Creating a realistic world map - Currents, Precipitation and Climate](https://worldbuilding.stackexchange.com/questions/1353) * [Creating a realistic world - Thermohaline circulation](https://worldbuilding.stackexchange.com/questions/25721) * [Universe Sandbox2](https://store.steampowered.com/app/230290/Universe_Sandbox/) This highly versatile program could be listed in a number of places on this list. It's here due to its frequent use to simulate weather patterns. But don't let that stop you from using it to simulate your solar system.... * [EdGCM](http://edgcm.columbia.edu/) Geoclimate model * [PCMDI](https://pcmdi.llnl.gov/?cmip5/) Program for Climate Model Diagnosis & Intercomparison (was CMIP5) * [Build Your Own Earth](http://www.buildyourownearth.com/) * [Monash Simple Climate Model](http://monash.edu/research/simple-climate-model/mscm/index.html) * [Open Climate Workbench](https://climate.apache.org/) * [ClimaSim](http://www.weathergraphics.com/climasim/) * [WxSim](https://www.wxsim.com/index.htm) * [Weather and Worldbuilding 101](http://fmwriters.com/Visionback/issue6/weatherandworld.htm) * [Planet Map Generator](https://topps.diku.dk/torbenm/maps.msp) – biome overlay * [EcoNet 2.2](http://eco.engr.uga.edu/index.html) Climate/ecosystem modelling online tool, Earth-like. * [Earth Flood Map](https://www.floodmap.net/) flooding map with actual Earth satellite imagery. It's worth noting that if all the ice caps melted, it's estimated the oceans would rise approximately [230 feet](https://www.usgs.gov/faqs/how-would-sea-level-change-if-all-glaciers-melted). * [Mean Temperature Calculator](https://web.archive.org/web/20220519173816/https://www.astro.indiana.edu/ala/PlanetTemp/index.html) Calculates mean planetary temperature given star mass, orbital radius, albedo and greenhouse gases as a ratio of Earth's values. * [Monash Simple Climate Simulator](https://sci-web46-v01.ocio.monash.edu/mscm/greb/cgi-bin/scny_i18n.py) showing the changes in temperature of various aspects of the Earth over time based on various affects. **Geography** * [Creating a realistic world map - Mineralogy](https://worldbuilding.stackexchange.com/questions/25084/creating-a-realistic-world-map-mineralogy) * [Creating a realistic world map - Fuel](https://worldbuilding.stackexchange.com/questions/25366/creating-a-realistic-world-map-fuel) * [How do I create realistic geography?](https://worldbuilding.stackexchange.com/q/19815/40609) * [Earth Impacts Effects Program](https://impact.ese.ic.ac.uk/ImpactEarth/ImpactEffects/) estimates the effects of an item impacting the earth. * [The Fundamentals of Physical Geography](http://www.physicalgeography.net/fundamentals/contents.html) * [Standford Roman Travel and Route Calculator](https://orbis.stanford.edu/) * [How to Create Sensible Plate Tectonics](https://worldbuilding.stackexchange.com/q/247575/40609) **Flora & Fauna** * [Creating a realistic world map - Vegetation/Biomes](https://worldbuilding.stackexchange.com/questions/23941/creating-a-realistic-world-map-vegetation-biomes) [Creating a realistic world map - Fuel](https://worldbuilding.stackexchange.com/questions/25366/creating-a-realistic-world-map-fuel) **History & Culture** * [RFF - History Creation](https://rollforfantasy.com/guides/history-creation.php) * [Music for Your Fantasy World](http://fmwriters.com/Visionback/Issue%2012/Themeartsin.htm) * [Historically Authentic Sexism in Fantasy](https://www.tor.com/2012/12/06/historically-authentic-sexism-in-fantasy-lets-unpack-that/) * [Everyday Life in the Middle Ages](https://www.bbc.co.uk/bitesize/guides/zm4mn39/revision/2) * [Donjon Fantasy Calendar Generator:](https://donjon.bin.sh/fantasy/calendar/) Free Calendar generator that allows you to change the number of days in a year/week/month, allows you to edit phases of the moon and lets you add Notes and Holidays. **Magic** * Brandon Sanderson’s Three Laws of Magic - [First Law](https://brandonsanderson.com/sandersons-first-law/), [Second Law](https://brandonsanderson.com/sandersons-second-law/), [Third Law](https://brandonsanderson.com/sandersons-third-law-of-magic/) * [World Building: Magic Systems](https://www.erindorpress.com/2013/11/world-building-magic-systems/) * [My Magic System Checklist](https://www.reddit.com/r/worldbuilding/comments/59qamy/my_magic_system_checklist/) * [RFF - Magic Creation](https://rollforfantasy.com/guides/magic-creation.php) * [RFF - Superpower Creation](https://rollforfantasy.com/guides/superpower-creation.php) * [Defining the Sources, Costs, and Effects of Magic](https://www.writing-world.com/sf/magic.shtml) * [12 Questions to Ask Yourself About Your Magic System](http://www.intergalacticmedicineshow.com/cgi-bin/mag.cgi?do=columns&vol=mette_ivie_harrison&article=079) * [How to Create a Rational Magic System](https://mythcreants.com/blog/how-to-create-a-rational-magic-system/) **Creature Design** * The [Anatomically Correct Series](https://worldbuilding.meta.stackexchange.com/q/2797/40609) of Creature Building Questions. * [RFF - Animal Creation](https://rollforfantasy.com/guides/animal-creation.php) * [RFF - Character Creation](https://rollforfantasy.com/guides/character-creation.php) * [RFF - Species Creation](https://rollforfantasy.com/guides/species-creation.php) * [Dragons and other large winged creatures](http://markwitton-com.blogspot.com/2018/05/why-we-think-giant-pterosaurs-could-fly.html) **Military, Weapons and Apparel** * [RFF - Armour and Weapon Creation](https://rollforfantasy.com/guides/armor-weapon-creation.php) * [RFF - Army Creation](https://rollforfantasy.com/guides/army-creation.php) * [RFF - Clothing Creation](https://rollforfantasy.com/guides/clothing-creation.php) * Roll for Fantasy - Warrior Guide - [African](https://rollforfantasy.com/guides/warrior-guide-african.php), [American](https://rollforfantasy.com/guides/warrior-guide-americas.php), [East Asian](https://rollforfantasy.com/guides/warrior-guide-east-asian.php), [Indian](https://rollforfantasy.com/guides/warrior-guide-indian.php) * [The Effects of Nuclear Weapons](https://www.deepspace.ucsb.edu/wp-content/uploads/2013/01/Effects-of-Nuclear-Weapons-1977-3rd-edition-complete.pdf) (1977). Please do not ask a question about nuclear effects until you've reviewed this document. **Cities and Societies** * [Creating a realistic world - Spreading languages](https://worldbuilding.stackexchange.com/questions/25396/creating-a-realistic-world-spreading-languages) * [Creating a realistic world map - Countries Borders](https://worldbuilding.stackexchange.com/questions/23820/creating-a-realistic-world-map-countries-borders?rq=1) * [Creating a realistic world - Governments](https://worldbuilding.stackexchange.com/questions/25524/creating-a-realistic-world-governements) * [RFF - Building Creation](https://rollforfantasy.com/guides/building-creation.php) * [RFF - City Creation](https://rollforfantasy.com/guides/city-creation.php) * [RFF - Society Creation](https://rollforfantasy.com/guides/society-creation.php) * [RFF - Name Styles](https://rollforfantasy.com/guides/name-styles.php) * [S. John Ross - Medieval Demographics Made Easy](https://web.archive.org/web/20180925185100/http://www222.pair.com/sjohn/blueroom/demog.htm) * [Software] [Medieval Fantasy City Generator](https://watabou.itch.io/medieval-fantasy-city-generator) * [International Standard Classification of Occupations (ISCO-08)](https://www.ilo.org/wcmsp5/groups/public/---dgreports/---dcomm/---publ/documents/publication/wcms_172572.pdf) **Economics** * [Creating a realistic world - Governments](https://worldbuilding.stackexchange.com/questions/25524/creating-a-realistic-world-governements) * [Money Matters for the Intrepid Traveller](https://cbbforum.com/viewtopic.php?f=29&t=6144&p=256399&hilit=money%20matters#p256399) * [List of price of medieval items](http://medieval.ucdavis.edu/120D/Money.html) * [donjon Medieval Demographics Calculator](https://donjon.bin.sh/fantasy/demographics/) * [The Domesday Book](https://www.rpglibrary.org/utils/meddemog/) on the web **Food & Farming** * [Creately food web designer](https://creately.com/lp/food-web-maker/) * [Insight Maker](https://insightmaker.com/tag/food-web) * [Visual Paradigm](https://online.visual-paradigm.com/diagrams/templates/interrelationship-diagram/food-chain-interrelationship-diagram/) **Simulators and/or Games** *This section is not for calculators. Please put calculators under the topical heading most appropriate above.* * [Solar System Simulator](https://simpop.org/solar-system/solar-system.htm) - A simple Sol system simulator demonstrating orbit speeds by distance and mass. Allows you to place known planetary bodies anywhere you want. * [Solar System Scope](https://www.solarsystemscope.com/) - Simulates the Sol system in remarkable detail, but does not allow modifications to the system. * [Solar System Simulator](http://www.scigames.org/game.php?id=planetfamilies2) - One of the most fun, it simulates both the orbits and the gravitational effects. You can make multi-sun systems and try to create stable planetary orbits. Colliding suns make bigger suns. Limitations make it cumbersome to create specific systems, but a lot of fun. * Questions asked using the [software-recommendations](/questions/tagged/software-recommendations "show questions tagged 'software-recommendations'") tag may have other options not included in this list. **Science and Technology** * [RFF - Fictional Technology Creation](https://rollforfantasy.com/guides/fictional-technology.php) * [A Slower Speed of Light](http://gamelab.mit.edu/games/a-slower-speed-of-light/). This game, developed by MIT, helps world builders understand the effects of special relativity and how things are "seen" as one approaches the speed of light (or, in the case of the game, by "slowing light down to walking speed.") * [Atomic Rockets](http://www.projectrho.com/public_html/rocket/prelimnotes.php) * [Medieval Technology](http://fmwriters.com/Visionback/Issue%2011/advcuttechnolog.htm) * [1989 Rockwell International Integrated Space Plan](https://cdn.makezine.com/uploads/2013/07/integratedspaceplan2color.pdf) * [Lexicon of Locks and Keys](https://www.historicallocks.com/en/site/h/historicallocks/dictionary/) **Science Calculators** * [Conservation of Momentum (Collisions)](https://www.omnicalculator.com/physics/conservation-of-momentum) * [Car Crash Calculator](https://www.omnicalculator.com/physics/car-crash-force) * [Physics inside a Rotating Space Colony Calculator](https://jsfiddle.net/nosajimiki/k98z2h1a/240/) **Language** * [Universe Factory](https://medium.com/universe-factory): [The importance of language in world building](https://medium.com/universe-factory/a-disease-of-mythology-the-importance-of-language-in-worldbuilding-d1a9d1f1e2f4) * Roll for Fantasy - Language Creation - [Part 1](https://rollforfantasy.com/guides/language-creation.php), [Part 2](https://rollforfantasy.com/guides/language-creation-part-two.php), [Part 3](https://rollforfantasy.com/guides/language-creation-part-three.php), [Part 4](https://rollforfantasy.com/guides/language-creation-part-four.php), [Part 5](https://rollforfantasy.com/guides/language-creation-part-five.php) * Roll for Fantasy - Body Language - [Part 1](https://rollforfantasy.com/guides/writing-body-language.php), [Part 2](https://rollforfantasy.com/guides/writing-body-language-part-two.php) * [Constructed Languages Stack](https://conlang.stackexchange.com/) * [The Language Construction Kit](http://www.zompist.com/kit.html) * [The International Phonetic Alphabet](http://web.uvic.ca/ling/resources/ipa/charts/IPAlab/IPAlab.htm) **Youtube Channels and Podcasts about Worldbuilding** * [Hello Future Me](https://www.youtube.com/channel/UCFQMO-YL87u-6Rt8hIVsRjA) * [Web DM](https://www.youtube.com/channel/UC7XFmdssWgaPzGyGbKk8GaQ) * [Shadiversity](https://www.youtube.com/user/shadmbrooks) * [How to be a Great Game Master](https://m.youtube.com/user/Bon3zmann/featured) * [World Anvil Worldbuilding](https://m.youtube.com/channel/UCf5MDxxTuT1OpwOxVfG-ofg) * [Writing Excuses on World Building](https://writingexcuses.com/tag/worldbuilding/) * [Artifexian](https://www.youtube.com/user/Artifexian) * [Biblaridion](https://www.youtube.com/channel/UCMjTcpv56G_W0FRIdPHBn4A) * [University course on writing by Brandon Sanderson; Episode 4 is about Worldbuilding and Episode 8 about Magic systems](https://www.youtube.com/playlist?list=PLH3mK1NZn9QqOSj3ObrP3xL8tEJQ12-vL) * [Science & Futurism with Isaac Arthur](https://www.youtube.com/channel/UCZFipeZtQM5CKUjx6grh54g) * [Phrenotopia's Alien Evolution Series](https://www.youtube.com/watch?v=0kbIoEx7mmc&list=PLbAr0DK7A_W5Fx4qJhXFnNeMbhox15tdi) **Worldbuilding Discussion Forums** [We've been asked](https://worldbuilding.stackexchange.com/questions/132660/worldbuilding-forum-or-other-conversational-place) about places to go for discussion beyond mere Q&A. There are several excellent long form discussion forums focusing on worldbuilding. * [**CBB**](https://cbbforum.com) -- a discussion forum catering to invented languages & worlds * [**Reddit Worldbuilding**](https://www.reddit.com/r/worldbuilding/) -- general worldbuilding forum * [**Reddit Fantasy Worldbuilding**](https://www.reddit.com/r/FantasyWorldbuilding/) -- a narrow focus * [**Reddit Fantasy Maps**](https://www.reddit.com/r/FantasyMaps/) -- fantasy cartography * [**Reddit Fantasy Writers**](https://www.reddit.com/r/fantasywriters/) -- for writers * [**GTX0**](http://gtx0.com) -- ConWorlds merged with Game Talk in 2019 * [**ZBB**](http://www.verduria.org/) -- another general purpose invented language & culture forum * Worldbuilding's own [**Factory Floor**](http://chat.stackexchange.com/rooms/17213/the-factory-floor) -- you love our answers, join the discussion! Those are the main ones, and there are certainly other highly specialised forums as well. **World-Building Software** *Software in this category is designed to help manage the process of worldbuilding rather than specific aspects of worldbuilding (e.g., climate simulation, mapping), which may be dealt with in greater detail with dedicated tools.* * [FrathWiki](http://www.frathwiki.com/Main_Page): a great place to store the articles you've written about your invented worlds, cultures, languages and histories; easy to use Media Wiki style, no unnecessary bells and whistles * [World Anvil:](https://worldanvil.com) Free tool (you can pay to remove ads). Allows you to consolidate your world building contents online. Covers timelines, geography, religion, allows for uploading and pinning maps, and a whole bunch of other stuff. * [Scabard:](https://www.scabard.com/pbs/page/main/About) Free with a private mode available for $40 yearly subscription. This is geared (heavily) towards RPG & TableTop campaigns but has many tools for general Worldbuilding. Offers: Map creation, Timelines, Event handling, Character/Group/Item/Location creation options, and graph options for mapping connections. * [ChronoGrapher](https://chronographer.net/info): a wiki-style notetaking and worldbuilding tool with support for deep time and history tracking. Features includes: interactive and interconnected maps, an infinite tilegrid editor, custom calendars and timelines, dynamic and automatic wiki articles, completely private projects and ability to collaborate. **Books** *There are a very large number of books about or contributing to worldbuilding. This is not the place to list them all. It is the place to list those that have been mentioned in questions and answers posted on this site. Please list the book (with link to Amazon or the author's website), the author's name, and links to the WB.SE posts that cite the book.* * [World-Building](https://rads.stackoverflow.com/amzn/click/com/B014V4EDAI) by Stephen L. Gillett, mentioned in [1](https://worldbuilding.stackexchange.com/q/139147/40609), [2](https://worldbuilding.stackexchange.com/q/120616/40609) (originally part of the [Science Fiction Writing Series](https://www.librarything.com/series/Science+Fiction+Writing+Series)) * [On Writing and Worldbuilding](https://www.amazon.co.uk/s?k=on+writing+and+worldbuilding) Volume One by Timothy Hickson, mentioned in [1](https://worldbuilding.stackexchange.com/a/148558/62187) ]
[Question] [ **Scenario:** While poking around in an alien ruin, scientists discover a gateway which offers instant transportation to an Earth-like world. **The Observed World:** The gateway leads to an area that is temperate (let's say it's similar to east coast of America, like Virginia/Maryland/Pennsylvania, for simplicity). The air is breathable, and there is an ocean visible within less than a mile. The gravity and day/night cycle almost exactly matches Earth. The planet has no visible satellites, natural or otherwise. There is flora and fauna, but no intelligent life. **The Actual World:** The "planet" is actually an artificial construct—a flat (coin-shaped) world created through technological (rather than supernatural) means. The size is similar to what Earth would be, were its surface peeled open like an orange, and flattened into a disk. Gravity is artificially generated and regulated to mimic Earth (so you won't be pulled at an angle as you approach the edge). The atmosphere is held in by an invisible field which forms a dome over the livable side of the world. The world orbits a yellow star similar to the Sun, and also rotates (like a [spinning coin](https://media4.giphy.com/media/6jqfXikz9yzhS/giphy.gif?cid=ecf05e47gnx6rycjbpxkyfcmtp2yybi8mbzq3s2y4lhaonu5&rid=giphy.gif&ct=g)), so the sun will appear to rise and set. **Question:** If a team of scientists are sent through the gateway with the purpose collecting flora/fauna/air/water samples, and observing the night sky (to determine the planet's location relative to Earth), what would tip them off that they're not on a typical spherical planet? Particularly, what would stand out to someone with a good grasp of general physics, or astrophysics, even if they had no reason to suspect that the planet was anything other than a typical sphere? I'm not looking for a mathematical proof, but rather something that visibly stands out and would make a scientist decide to perform such a proof in the first place. Their available technology is modern-day: telescopes, laptops, quadcopter-mounted cameras, etc. [Answer] ## Daybreak and nightfall would be spectacular A flat coin shape would have a day face and a night face with sudden transitions because unlike a sphere, it blocks all sunlight with its own shadow, there is no refraction around the sphere. The sunlight also passes through much more air when close to the horizon. If you start at noon, things would appear quite normal and stay so into twilight as the suns moves lower in the sky. A few minutes before sunset the sunlight starts fading much more rapidly than it would on Earth. The effect would be like the sun sinking into clouds even on the clearest day, until the sun barely outshines our moon and the sky would be as dark as night while the sun is still above the horizon. The moment the sun passes the horizon, it will be completely dark. There are no shimmering clouds or scattered glow, only pure darkness. The scattered light from the edge simply can't reach you through thousands of km of air. Daybreak would arrive just as suddenly, with what looks like a moon rising in the night suddenly increasing in brightness until normal sunlight a few minutes later. If the observer would be very close to one edge of the world, sunrise and sunset would be asymmetrical, with the closer one fading closer to the horizon. No scientist is going to take long in figuring this one out. --- EDIT: I've updated my answer for a bit more scientific accuracy, as many comments pointed out the effects should be noticeable even before the sun sets, and they are right. Below is the science behind the answer, that I could find online. The air in our atmosphere reduces the intensity of light going through it by scattering, absorption and reflection. Even at the shortest path (straight down when the sun is at zenith) only about 75% of visible light makes it to the surface. This is a well-known and important effect in Astronomy and other fields of science and modelled as ["Air Mass" (wikipedia)](https://en.wikipedia.org/wiki/Air_mass_(astronomy)). The lower the sun is in the sky, the higher the amount of air mass the light travels through. On Earth, the air mass is about 38x higher when the sun is at the horizon, resulting in a drop in light intensity in the environment from 100k+ lux to only ~400 lux on a clear day. On a flat world with a similar atmosphere this would be about the same until the sun gets close to the horizon. Then the light needs to pass through much more atmosphere making it much darker. I drew this for a visual impression. The blue and purple areas show the atmosphere of a round and flat world respectively. The curve is exaggerated for clarity. It's roughly to scale for a 100 km high atmosphere, but only the lowest few km have enough density to matter. [![diagram of sunlight at various angles on a flat vs curved world](https://i.stack.imgur.com/wBE2r.png)](https://i.stack.imgur.com/wBE2r.png) It's easy to see that the difference in air mass is unnoticeable until about 85 degrees from zenith (5 degrees above the horizon). This is 20 minutes before sunset on Earth. 12 minutes before sunset (87 degrees) the difference is perhaps 20%, noticeable but easily dwarfed by variation due to atmospheric conditions (hazy sky). 6-7 minutes before (88-89 degrees ) it's already as dark as it should be as sunset and then in the next few minutes the sun and daylight will fade to perhaps only the strength of a full moon before setting. To back this up with some numbers: The Wikipedia article has a [graph](https://upload.wikimedia.org/wikipedia/commons/8/8d/AirmassFormulaePlots.png) with several models. Conveniently, the most basic one is the "plane parallel" which is a flat world. It's given only as a reference because it is invalid at high angles, but exactly what we want to compare. When looking at the graph, the air mass at sunset (90 degrees) is ~38 for most models, a value the plane parallel line already reaches between 88 and 89 degrees. The air mass then increases rapidly, approaching infinity because it doesn't account for the limited radius of the flat coin world in this question :-). [Answer] Apart from the horizon topic that was already covered by Separatix and Ctouw, they could quickly verify their observation by measuring the angle towards the sun at different points of the planet at the same time). Those angles will, much unlike at home, be almost identical, since they are measured from a plane a large distance from the observed object (the sun), while comparably close to each other, even if they are on different continents. Also, they will quickly notice that they won't have time zones, for exactly the same reason. As a result, all programmers of earth will, almost immediately after that discovery, migrate to the new planet, and will forever be happy coders that don't have to deal with time zone handling any more. [Answer] Horizon effects would be the first signal. As a quick and dirty calculation, the distance to the horizon in miles is half your height in feet. Given their visual range is going to be far greater than that, you have two options, either the world is absolutely vast (even though gravity is Earth normal) or it's flat. They'll quickly realise something strange is going on, after that it's a matter of working out what. Spread out, do some triangulation and they'll find the answer. Then the sunset will be all wrong. [Answer] # An Edge Not sure why this has not been said, but when you go for a long enough walk and get to the perimeter of the disk planet, there is an edge. In the Truman Show, the edge looks like this: [![The Edge](https://i.stack.imgur.com/0q89l.jpg)](https://i.stack.imgur.com/0q89l.jpg) [Answer] ## Triangles Most of the methods posted involve the sun or the sky, but since the planet was created using some very advanced technology, it's possible these effects are hidden. Instead, a simple and foolproof method is to measure a (sufficiently large) triangle. ## Why? You might think the angles of a triangle add up to exactly 180°, but this is only true on a flat surface. On Earth (and any sphere) the angles of a triangle actually always sum to more than 180° (up to 540°). There are similar distortions in area, and other properties. So, as soon as they seriously consider any 3 points on the planet that are far enough apart, someone clever will notice something is unusual (180° triangles). As a bonus, because this is a purely mathematical property of flat surfaces, there is absolutely no way to hide the flatness of the world. [Answer] **There will be no horizon line or it would look way further than on actual Earth** The horizon line is caused by the Earth being a sphere, so that when you look straight in front of you, at a certain point you can't see things because they are hidden by the curvature of the Earth itself. In the world you describe, you would see what is in front of you up to the edge of the "planet"; or, depending of its span, instead of having a horizon line, distant objects would progressively disappear into "distance fog". But you would see way further than on actual Earth anyway. [Answer] [Eratosthenes](https://en.wikipedia.org/wiki/Spherical_Earth#Antiquity) made the first estimate of the size of the spherical earth. He did so by measuring the length of the sun's shadows while at two different locations. One location was much further north than the other, and the length of shadow told him how much the earth surface curved between the two. His measurments were both performed on the summers solstice when the sun was at it's highest point in the sky. The known distance between the measurement points and his calculated difference in the sun's shadow angle allowed him to calculate the curvature (size) of the earth, within 5-15% of its true value. So if you are limited to low tech, the way to measure a planet's curvature is if two people were to measure the angle of the sun's shadow at noon on the same day at two distant points (exactly north-south of each other), and if that angle is different at the two locations, that would imply that the earth is curved and probably spherical, or at least curved in the north to south direction. The time-zone answers given by other answers here would prove the earth is also curved in the east-west direction, but to use that method requires precise/reliable clocks for the two measurements to occur at the same time but east-west from each other. Which is also one of the reasons why sailors [historically needed](https://en.wikipedia.org/wiki/Marine_chronometer) precise clocks for navigation; this allowed them to know how far east-west they were when out of sight of land. What time noon occurs at depends on how far east-west you are. If you know the time, the sun's position tells you where you are (east-west). If you know where you are (east-west), you can use the sun to tell you what time it is. Given your premises of scientists with higher tech, I would say one tip-off to them of the flat planet scenario would be if one scientist were to video-call another while they were located at widely different points on the flat planet, and one of them notices that the sun's shadows appears to fall at the same angle at the same time in both locations. [Answer] **No clouds near the horizon** On a cloudy day when you look at the horizon where the sky meets the water over the ocean, you see clouds appearing to touch the water even though those clouds are in the air. On a flat world the clouds would not do this. They would get close to the horizon, but never touch. [Answer] # Atmospheric readings would be weird On Earth, the atmosphere is a spherical layer around a spherical earth. However, you say that the atmosphere is a dome over the world. If the dome is a physical object, it would have to be close to round to be able to support its own weight. If it's held there by the gravity, most of it would spill over the edges. If it's an invisible force field, the easiest way would again be a spherical field. Assuming the dome is round... * Either the entire atmosphere weighs just as much as Earth, which leads to a much thinner atmosphere; * Or the atmosphere is just as dense as on Earth, which leads a much larger atmospheric pressure; * Or the atmosphere changes density in a different way than on Earth, which means that incoming light is diffused differently. Assuming the dome is a fixed-height force field, then the lower view angles would have to travel through far more atmosphere to reach you compared to on earth, again affecting diffusion. # Compasses would not work like they do on Earth Earth's magnetic field is caused by molten metal deep inside the core moving around and generating electric currents. Because of the Coriolis effect, this field is roughly aligned with Earth's rotational axis. However, on a flat disk, there probably is no molten core, and even if there was one, it wouldn't generate a magnetic field in the way that we know it on Earth, because the molten metal would flow differently and there wouldn't be as strong a coriolis effect. [Answer] First, why would it be spinning? Consider a coin spinning clockwise from your point of view. The leading (top left) edge moves with the spin, as does the bottom right. Someone standing at either point would experience higher gravity than someone in the centre. An observer at the trailing edge would experience negative gravity. It's the same concept as spinning cylindrical space stations to generate artificial gravity-it varies according to your direction of movement. A disk spinning like a coin would be obvious the moment you take a few steps orthogonal to the spin axis. If it's spinning like a flat top, centripetal force increases as you travel closer to the edges. Again that should be fairly obvious. Not to mention the sun travelling the other way at "night". If anything, the only way for this to work is with the classical flat earth model, where the disc is at rest and everything rotates around it. So, now that we have a stationary flat disc, under a VR dome, how does the air and water circulate? Cold generators at the poles and heat generators at the centre? Pressure generators at the rim? As someone pointed out, if we assume godtech, anything is possible. Assuming a circular world however, geometry would indicate everything moves either to or away from the centre. [Answer] # Weird atmospheric effect. We have a disc-shaped world which is either illuminated (albeit with varying angle) or in the dark. There is no circulation between Lightside and Darkside. As a result, the atmosphere gets very little horizontal circulation, or none (this depends on how thoroughly the gravity generators compensate with height the centripetal force from the world's spinning: they would need to shoot upwards on the axis and shoot at an angle, and more powerfully, nearing the edges). Vertically, there would be only convection. Now during the night the heat escapes into space, and the atmosphere cools off. During the day it warms up *starting with the lower layers*. Under these conditions, light gets refracted in the atmosphere and gets bent upwards. This, combined with a horizon much farther than the Earth value of around 5 km, would cause the illusion of being at the bottom of a shallow cup. At that point, I'd expect that the curiosity of pretty much any scientist regarding the actual shape of the world he's on would be quite aroused. Travelling some fifty kilometers with some device capable of measuring the Sun's angle with a high time precision would then quickly hint about what's happening. More subtle tests with the local intensity of the gravitational field would show it's artificial (actually, I suspect an artificial field with the needed characteristics of directionality just can't be produced. Perhaps, the disc might be made to orbit a massive black hole orbiting around the sun, so that it doesn't spin around its axis like a coin. The disc would need to be slightly rounded or the black hole very far, though). [Answer] One example of a similar scenario I've read is "[Missile Gap](https://subterraneanpress.com/magazine/spring_2007/fiction_missile_gap_by_charles_stross)", a short story by Charles Stross. This follows the reactions of the Cold War superpowers to the entire planet being transplanted onto the surface of a disk with the mass of 50,000 suns just after the Cuban missile crisis. The main effect observed is the altered geography, which shifts the balance of power as ICBMs become no longer in range, and the near-uniform gravitational field, which prevents any further space exploration. [Answer] Other clues will show up before this one does, but it's worth noting anyway. **Gravity might be weird anyway.** The generator accounts for essentially all of the gravity, and somehow projects\* it up like a floodlight so you feel gravity only from the surface within meters of you. This will make the strength of gravity independent of altitude within a cone thousands of kilometers high. The tighter the floodlight, the taller the cone. The wider the floodlight, the farther from the edge gravity stops pointing down. If you decrease the width near the edge, you can make a roughly dome-shaped region above the disc where gravity is actually stronger along the "surface" of the dome than within. If you don't want this stuff to be true, then the generator has extra magic that makes its field violate the inverse-square law. \*It's a static field so nothing's really being "projected", but the floodlight analogy holds up pretty well otherwise. [Answer] **Euclidean Geometry** On a sphere a triangle's interior angles add up to more than 180 degrees because of the curvature. On a flat world, Euclid would rule supreme. An accurate survey would reveal that triangles have 180 degrees hence no curvature. [![enter image description here](https://i.stack.imgur.com/yFAlm.png)](https://i.stack.imgur.com/yFAlm.png) [Answer] # The Clouds Due to effect of the horizon, there'd be clouds approaching it. Since this place is flat and not round, it cannot have a horizon. So there wouldn't be clouds on the horizon. (There wouldn't be a horizon :O) # Atmospheric Effect There wouldn't be day and night at the same time. The entire disc (if you will) will be either be at day or night. # The edge There'd be an edge. Since it's not round and there aren't any buildings like in Pennsylvania or Virginia, it'd be easy to see too. [Answer] My first thought was observing the horizon, but others have mentioned that. Second thought: You say there is artificial gravity, which I presume means a uniform force over the entire surface. Then you say there is a dome to hold in the atmosphere. If by "dome" you're implying a curved surface, then the dome is closer to the ground near the edges than at the center. Which means there is a taller column of air near the center. Which means the air pressure must be higher. If the scientists travel far enough, the difference in air pressure will be noticeable. If the scientists travel far enough, sooner or later someone should notice that there is a fairly uniform average temperature over the entire world, rather than cold poles and hot equator. Which brings to mind that sooner or later someone is going to try to figure out their latitude and longitude and calculate the size of the planet, at which point they're going to figure it out geometrically. [Answer] Most was said, but nobody spoke of seasons. If axial tilt is zero (the "coin" stands perpendicular to the orbital plane and spins like a top), there would be no season. However, if the planet is tipped and spins on a diagonal axis, it will be the same season everywhere. I agree, though, that other effects mentioned will catch the eye more quickly. [Answer] ## It's the same time everywhere! The expedition arrives. One person begins taking pictures of the night sky, rapidly determining the location of the [celestial equator](https://en.wikipedia.org/wiki/Celestial_equator). I'm assuming the pole stars are harder to find, because they will be directly in the plane of the coin. They conclude they are on the equator. The rover teams branch out in different directions in motor boats, hover craft, ultralight aircraft, and optionally robotic walking vehicles. They use inertial navigation (accelerometers) as a substitute for GPS, generating an accurate map of the landscape. **But which way is North?** They are going in all directions. If they move east or west, the star overhead at base camp will have gone overhead already or not yet arrived, giving a sense of the planetary radius. If they go north or south, the celestial equator will appear tilted and a pole star will become apparent. *NONE of this happens. The planet has an infinite radius and the local time is the same everywhere!* (Infinite until they fall off the edge, anyway) First they may consider something is wrong with their measurements, it's a very large world, they're in a Mimas-like flat spot. But the further they go the more impossible the data looks: no way to tell latitude with a mariner's astrolabe or any more sophisticated instrument. No way to tell longitude by the time. The world... is flat! [Answer] There would be a few things, but one of the major ones would be an appeared incline as you moved away from the center. There is a great youtube video on this topic, and it's how I got this idea. <https://www.youtube.com/watch?v=VNqNnUJVcVs> The main point is up to about 1:53. [Answer] [The portal outlet would have to be near the centre; if it is near the edge, space will immediately look different in different directions, to the visitors, because of the different thickness of the air. (...Unless the air is perfectly translucent... which would raise suspicions.)] [The disc must spin around its diameter, not its centre; otherwise, there will be dramatic centrifugal force differences with very obvious effects near the centre.] [Anyone who looked through a telescope from a high point would be able to see (not automatically implying *notice*) that the horizon was infinite. The aliens would presumably compensate for this by making the landscape universally hilly (or perhaps slightly curved (inwards *or* outwards), or completely flat). Regardless, at least one scientist would probably start to wonder...] I am thinking that the immediate obvious difference will be in the types of animal and plant. (If they are imports from a spherical world, then they will be okay initially.) The seasons have to do with, not only the axial tilt of the Earth, but also the differential sun heating from north to south... which would not work with a flat surface. That is... there would be no seasons. The scientists would begin to notice this after a number of weeks, but the animals would be obviously relevantly very different from Earth animals from day one; they would neither migrate nor change with the seasons. There would be only one mode of life, for every single plant and animal... not to mention the terrain. No scientist studying the flora or fauna could possibly miss this -- at least subconsciously initially, and probably consciously within 24 hours. (From there, I would guess it would be only a few hours until someone suggested the obvious but fantastic explanation, and only a few hours more until someone started working on checking it.) [Of course, if there is *anything* that would give the game away easily, the whole scenario is suspect.] One might expect the aliens to compensate for this. The obvious easy way would be to make the ground more reflective in the north and south, but I imagine that that (in concert with the atmosphere issues) would have undesirable effects. However, nothing along those lines would work anyway, as seasonality near the equator depends on the sphere thing. The aliens have to either engineer a whole artificial seasons system or just leave the thing as it is. In turn, then, the obvious inference is that the homeworld of the aliens does not have an axial tilt. It would still have cold poles, though. Thus, that difference remains -- no seasons, but latitude temperature variations. This gives us a variety of different animals and plants, every last one of which is suited to only one temperature. ...And I shall stop there. [Answer] **The planet's magnetic field would be a lot different/non-existant** *I think this is plausible, but I'm not sure about the specifics.* The Earth has a magnetic field because its full of churning molten iron. This makes compasses work, protects us from some radiation from space, and sometimes makes auroras. I assume a flat artificial planet would not have any volcanic or tectonic activity, and thus no magnetic field. (Maybe there is an artificial one?) But without one, everyone would be getting blasted with a lot more radiation every second, and some instruments might pick that up. If they don't have proper detectors, then they could still see the effects indirectly. Maybe over time a lot of people get skin cancer. Maybe the radiation causes a much higher rate of computer errors than they expect. Airplanes usually have triple-redundant processors for essential computations because there is a higher likelihood of this kind of thing happening at 30,000ft than on the surface. ]
[Question] [ T-Rex Forever LLC has a mating pair of [Tyrannosaurus rex](https://www.nationalgeographic.com/animals/prehistoric/tyrannosaurus-rex/). They're a bit shady on how they got them, time travel, cloning...they won't say. Third-party biologists and paleontologists have examined the pair and their first clutch of offspring. They are definitely real. Somehow, T-Rex Forever goes out of business. As a last act, they release this breeding pair out into the rain forests of Costa Rica. **How long can the T-rex' survive without starving in an environment without significant megafauna?** Never mind that any humans anywhere near a T-rex will be highly inclined to hunt it down and kill it. We aren't worried about diseases (infectious or metabolic) that the T-rex might catch, we are only worried about the predator-prey relationship between a T-rex and the things they eat. No other dinosaurs were released, just these two T-rex'. My assumption is that without herbivore [megafauna](https://en.wikipedia.org/wiki/Megafauna) to prey on, or with scarce megafauna, it wouldn't be too big of a deal to release a mating pair of T-Rex into the wild. There wouldn't be enough for them to eat and they would starve before too long. (I'm using the "bigger than humans and not domesticated" definition of megafauna.) [Answer] # A young Tyrannosaurus Rex would be eaten If you've ever looked at collections of dinosaur fossils, you might wonder about why there are really big predators (like T. Rex) and really small ones (like Velociraptor, actually the [size of a big turkey](https://en.wikipedia.org/wiki/Velociraptor#Description)) but nothing in between. That is because Tyrannosaurus was the mid-sized predator. [![enter image description here](https://i.stack.imgur.com/35CBU.jpg)](https://i.stack.imgur.com/35CBU.jpg) Above is the growth chart for T. Rex. Notice that T. Rex takes about 10 years to grow to the size of grizzly bear; and won't reach full size until it is more like 20. A lion, on the other hand, rarely even lives that long in the wild. Wikipedia gives the average age of a male at 10-14 years. Meanwhile a cub hits sexual maturity in 2-3 years. So there is the problem. A young tyrannosaur would have to survive for 5 years at least avoiding predators. Just looking at Costa Rica, a baby tyrannosaur would be avoiding otters, racoons, weasels, foxes, grison, tayra, skunks; a predator for every habitat. He wouldn't be safe in the trees, on the ground, or in the water. And then if this tyrannosaur survived to 10kg, he is still potential food for a cougar or jaguar. You might think, well baby T. Rex survived just fine in the Mesozoic, why is so hard about now? The difference is endothermy in all the creatures that baby T. Rex would be competing with. Warm blooded creatures are much more active than cold blooded. In the modern world, T. Rex isn't keeping away from lizards and snakes and proto-mammals; it is avoiding high metabolism predators that have to eat [half their body weight each day](https://www.livescience.com/57475-weasel-facts.html). The whole paradigm of 'have a lot of eggs and hope for the best' is literally extinct in today's world for large animals. If you want a small baby to survive to a big animal, you need to take care of your offspring, and you need to make it grow faster. You need to feed it milk, which means that you need to be a mammal. Exceptions in modern ecosystems are strictly limited. # A big Tyrannosaurs Rex would starve Can dinosaurs run? Not very fast, probably, given their sizes. In the olden days of the Mesozoic, the way to protect yourself was to have lots of offspring, and grow to massive size. After all, we have just gone over how long it takes a T. Rex to get to huge size. Huge T. Rex are rare! Most of the T. Rex that your average [hadrosaur](https://en.wikipedia.org/wiki/Hadrosaurid) encounters on a day to day basis are going to be much smaller; too small, in fact to bother a 6 ton hadrosaur. Herbivores evolved for size (like [sauropods](https://en.wikipedia.org/wiki/Sauropoda)) or toughness ([ceratopsian](https://en.wikipedia.org/wiki/Ceratopsia) or [ankylosaurs](https://en.wikipedia.org/wiki/Ankylosauria)). Its pretty hard to argue that any of those three dinosaurs was designed to outrun a predator. Today, if you are a large herbivore, you protect yourself by running. [![enter image description here](https://i.stack.imgur.com/hvg2D.jpg)](https://i.stack.imgur.com/hvg2D.jpg) Now, lets address the T. Rex life cycle. As a newly hatched dino, the T. rex can probably find enough to eat with lizards and rodents and what have you. But as it gets bigger, it starts to have a problem. What does a 25 kg T. Rex eat? Its a bit big to be going after mice. It can't climb trees like the comparably sized ocelot. It can't run as fast (or more importantly, as long) as a coyote to track down small deer in a forest. The best it can do is scavenge. What does a 100 kg tyrannosaur eat? There is no way it is going chase down a deer. Or even a peccary through thick brush. Those creatures are both designed to evade jaguars. A jaguar will be stealthier, due to its low profile, and much more agile in a chase through the forest, due to having four legs. Lets say that this Tyrannosaur somehow makes it to 500 kg....now what does it eat? It isn't fast enough to catch anything anymore. There is no thing slow enough for it to overpower with size. Maybe 10,000 years ago it would feast on ground sloth and elephants, but those aren't around any more. # The closest thing to proof When North America and South America come together, a few million years ago, the continents exchanged predators. From the North came the cats, like sabretooths and cougars and jaguars. From the South came the [Terror Birds](https://en.wikipedia.org/wiki/Phorusrhacidae). Weighting up to 150 kgs, they are in many ways an analogue of the juvenile T. Rex in the 5-10 year old range. They could run fast, had excellent vision, and powerful beaks and claws. They are also extinct. The big cats are not. # Conclusion I tried to make this as short as possible. It is quite impossible for me to cite every little statement in here, so you will have to do your own research to see if you agree with me. The bottom line is that the way animals were designed and that the ecosystem interacted in the Mesozoic was radically different from how it works today. In the Mesozoic, there were tons of immature animals of every size, enough to provide a continuous buffet of meals in all weight classes. Today, mammals power grow their children to full size in 2 or three years; there just aren't that many half-sized deer or what have you to catch. Today, animals are built for the chase. Utilizing the mammals warm blood, every good prey item from rabbits to antelope to horses is designed to run away, fast, and with endurance. T. Rex simply isn't built like that. Even if it were a stealthy stalker (which is dubious), it would not have the agility on two legs to catch the deer or wild pigs it would need. No, the age of the T. Rex is firmly over. ### Endnote Question says 'modern ecosystem.' The possibility of T. Rex gorging on cattle is right there, but since the question is whether it would survive in the wild, I'd say it is a resounding no. [Answer] Randall Munroe has done most of the work for me already [here](https://what-if.xkcd.com/78/). In summary, a T-rex requires approximately 40,000 calories per day, that's equivalent to approx 40 kg of meat per day. According to the [Costa Rican Travel Agency](https://www.costarica.com/wildlife/), T-rex would feast on crocodiles (average 400 kg), tapirs (150–400 kg) giant ant-eaters (up to 40 kg), peccaries (20–40 kg), and jaguars (50–100 kg)(if it could catch one napping). If they can hunt in water, then manatees (200–600 kg) are on the menu too. Jurassic park has some delightful carnage showing that humans (ave. 62 kg) are a valid food source. There's definitely plenty of food there for them, so the only unknown is whether or not the T-rex is capable of hunting in dense rainforest. Unfortunately, the evidence seems to point toward the T-rex [living in forested areas](https://www.nationalgeographic.com/animals/prehistoric/tyrannosaurus-rex/), so there seems to be no upside to your plan! (Unless you're planning on writing a sequel) It might be safer to release them on an island off the coast of Costa Rica: [![An island off the coast of costa rica](https://i.stack.imgur.com/dzDac.jpg)](https://i.stack.imgur.com/dzDac.jpg) [Answer] **Megafauna?** [![costa rican cattle](https://i.stack.imgur.com/T7DpG.jpg)](https://i.stack.imgur.com/T7DpG.jpg) <https://lecherialaslapas.com/2013/09/08/purebred-watusi-calves-born-in-costa-rica/> There are really a *lot* of cattle in Costa Rica. <http://mitigationandtransparencyexchange.org/news/2015/03/12/costa-rica-leads-the-way-towards-sustainable-livestock-management/> > > Nationally, more than 45,000 livestock farms employ at least 12% of > the Costa Rican workforce and occupy over 35.5% of the territory. > > > <http://www.nytimes.com/1972/07/04/archives/many-americans-are-raising-cattle-in-costa-rica.html> > > Americans are not the major factor in the 39 million pounds of beef > Costa Rica exports each year to the United States. But they are > certainly a growing part of it and the cost of doing busi ness in the > United States is the reason. A ranch here that supports 1,000 cattle > and costs $250,000 to buy is about half the cost of a comparable ranch > in the American Mid dle West. There are no restrictions on the amount > of land a foreigner, can buy in Costa Rica. > > > I think that in Costa Rica your T.Rexes would find cattle (and it would not take long), and eat them. Cattle would be easy picking for a T.Rex. When the cattlemen come to kill them, your T.Rexes will point out your paragraph where it says not to worry about that. [Answer] So [Will](https://worldbuilding.stackexchange.com/a/99848/34824) and [JeffUK](https://worldbuilding.stackexchange.com/a/99846/34824) have covered the what would they eat part, but what happens after that? You're a little bit sparse on the details (and our knowledge of T.Rex breeding is fairly sparse) but it seems that T.Rex reached their full adult weight around the [age of 18](http://dinosaur-world.com/tyrannosaurs/tyrannosaur-growth-rate.htm), but could quite possibly have started breeding at [age 16](http://www.abc.net.au/news/science/2016-03-16/pregnant-t-rex-discovery-sheds-light-on-evolution-of-egg-laying/7251466) so let's assume the pair were 16 when the company first 'acquired' them. Assume another couple of years in captivity before the company went bust and released them and they are roaming the Costa Rican wilderness approx. age 18. Unfortunately hard data about number of eggs is pretty much non existent. It is speculated that like their descendants (birds) dinosaurs practised parental care, and this is one reason why we don't find many eggs or dead young. If parental care is practiced then you would assume only one clutch of eggs per year (or possibly even one clutch every other year) and that each clutch is small. Eagles lay an average of 1 - 3 eggs but ostriches lay 7 - 10. Let's err on the side of caution and assume eagle like, which is an average of two eggs. If we assume that the pair lays two eggs per year till they die aged 30 that's 24 individuals, but by the time the first pair are dead the oldest offspring will probably not even have reached breeding age. Even if we assume no human interaction at all and they live their lives completely unmolested you'd probably have 40 - 60 years before you'd have any real danger of a population explosion and serious effects on the ecosystem. When you take into account the complete lack of genetic diversity too it's far more likely the T.Rexs will either die off (again) or survive in very small numbers and cause little trouble for the ecosystem. [Who knows, they might even help it...](https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=15&cad=rja&uact=8&ved=0ahUKEwjQs5aEyoDYAhXN3KQKHRbbAUwQFghtMA4&url=https%3A%2F%2Fwww.yellowstonepark.com%2Fthings-to-do%2Fwolf-reintroduction-changes-ecosystem&usg=AOvVaw2vm-Pxys_xWOsTFboTi343) [Answer] Besides all the other "they'd all die" reasons... <https://en.wikipedia.org/wiki/Minimum_viable_population> > > Minimum viable population is usually estimated as the population size necessary to ensure between 90 and 95 percent probability of survival between 100 and 1,000 years into the future. The MVP can be estimated using computer simulations for population viability analyses (PVA). PVA models populations using demographic and environmental information to project future population dynamics. The probability assigned to a PVA is arrived at after repeating the environmental simulation thousands of times. > > > MVP does not take human intervention into account. Thus, it is useful for conservation managers and environmentalists; a population may be increased above the MVP using a captive breeding program, or by bringing other members of the species in from other reserves. > > > [Answer] While many of the answers cover much of the ground, I think the biggest unknown is how, exactly T-Rex lived and worked in family groups. I have seen some speculation that the adults would nest and then nurture the T-Rex chicks. As they reached adolescence, the "gangly" teenagers would have proportionally longer limbs and lighter bodies than the adults, leading to speculation that family groups would send the adolescents to "drive" the prey to the lurking adults waiting in an ambush position. This sort of hunting strategy actually makes sense considering many of the potential prey dinosaurs were heavily armed and armoured (and probably sporting nasty dispositions). [![enter image description here](https://i.stack.imgur.com/NJwN0.jpg)](https://i.stack.imgur.com/NJwN0.jpg) *Reconstruction of a T-Rex chick. The proportionately longer limbs would make it an efficient "driver" for the hunt* This sort of hunting strategy, if it *was* how a flock of T-Rex hunted, doesn't really translate well to either the dense rainforest environments of Costa Rica, nor the more open pastures cattlemen would have their herds on (more because cattle would react differently to the presence of hunting T-Rex than the T-Rex has evolved to deal with). The other issue is related to the genetic variability of the T-Rex being released into the wild. Small family groupings like this exist even within modern hunting mammals, but generally when the young males reach sexual maturity, they either leave on their own or are driven away to stake out new territories and seek mates outside the family group. Given there is only one breeding pair in existence, this could lead to a situation several years down the line where young male T-Rex's are staking out territory across large swaths of Central America, but have no viable mates. Any who remain with the initial brood (or move back to take over) will be mating with their sisters, with pretty predictable long term results. Assuming there is a moratorium on hunting and killing the T-Rex flock for ecological or other reasons, the new result may be to have another team of scientists either try to recreate more T-Rex's via the initial process, or capture some of the existing flock and then do some genetic engineering of their own to modify the DNA and release "2nd cousins" into the wild to ensure viability of the free range T-Rex community. Of course if you are planning to go that far, then recreating the rest of the Cretaceous ecosystem is probably quite doable as well (although the entire menagerie will have to be imported back to the American West Coast to live in the Douglas Fir forests, which is probably much closer to their ecosystem than anything else these days. Tourists will be thrilled in the moments before their cars are kicked off the road and they are eaten....) [Answer] As others have pointed out there is megafauna in costa rica although most of if is domesticated (35% of the land area used for ranching) or invasive (hippos) but the rexes will not care about that, if anything having them in nice convenience pens they can't get out of will make it easier. there is also middle sized stuff which they can eat, wolves can live of mice if they have to for a while after all. Costa rica is not however a great environment for them, t-rex was believed to live in a savannah like environment, so they will likely be drawn to the human areas with more open space and more importantly easy food. They will become a major danger long before they starve. Africa may be a "better" *for them at least*, choice. The real issue is costa rica is covered in their two closest living relatives birds and crocodilians so the chances of them catching a disease is high although they may be just as likely to be resistant to everything around since their physiology is different enough. Parasite may be a bigger issue as their immune systems will not be ready for modern ones, you might be able to hand wave this, crocodiles do not get many digestive parasites after all. [Answer] During the megafauna era oxygen concentration was rather high (that's what led to such big animals/plants in the first place) your T-rex would have some troubles breathing normally which would lead it to have troubles catching prey. Ignoring the obvious oxygen thing and considering the amount of food one of this must ingest i'd say it would die in more or less ~10ish days because it would use most of it's energy to catch prey that would be far less than the energy used. *Edited*: To clarify a bit the my second point, the daily caloric intake of a t-Rex can't be sustained for long periods of time with the current fauna we have . Even if it would feed mostly on elephants or try to (gl being sneaky at that size) the energy needed to fight one is rather high don't forget that the target would be adults not the infant ones (more mass=more calories) and as ferocious as a T-Rex might be or look if you smack it hard enough it would tip over like a cow . [Answer] We do have megafauna today, the question is if your T-Rex is able to go fishing? Think about whales and other large sea-animals. Now, a T-Rex probably can't swim, but depending on the situation, stranded whales would fill it up for a while. The rest would be cattle, I assume. ]
[Question] [ It's been a good year for me as an Evil Overlord. Lots of princess kidnapping turned into sizable ransoms, several of my Doomsday Devices were sold for high prices at auction, and my Minions have been working harder than ever. In fact, I'd like to think I'm moving up the Evil Overlord ladder. To capitalize on my profits and cement my position in the world, I've decided to construct an Evil Tower somewhere in the world. It's going to be ~500 meters tall, and I've got the blueprints more or less figured out, but it doesn't quite scream "evil". Yet. To guarantee that everyone knows exactly who they're messing with, I'd like to have a persistent storm cloud hovering above my tower. **Goals:** * At least half a kilometer high and a kilometer in diameter, ideally floating a few hundred meters above the top of my tower * Must be stable and persistent under most weather conditions. This will depend on the suggested location, but the cloud should be present at least 90% of the time * The cloud does not need to be composed of the normal H2O molecules, but answers using more common and less environmentally disruptive substances will be preferred * Ideally, the cloud will not produce large quantities of rain but some precipitation (less than 1 meter per year) is acceptable * The cloud is dark grey or black (none of those cute sheep-looking cumulus clouds) * The cloud occasionally discharges lightning bolts to carefully positioned lightning rods in the top of my tower **How can I engineer my Evil Tower or the surrounding environment to fulfill the above requirements?** [Answer] **Ash cloud.** [![ash cloud with lightning](https://i.stack.imgur.com/Uiyn5.jpg)](https://i.stack.imgur.com/Uiyn5.jpg) Your tower is hollow, and the interior is a conduit to the underworld - perhaps the column extends straight down through the underworlds of [K'n-Yan, Yoth and N'Kai](https://www.yog-sothoth.com/wiki/index.php/K%27n-yan) all the way to the hellish interior. Strong winds and gouts of charged ash emerge from the black cloud which plumes forth from the apex, and as with volcanoes the cloud crackles with charge which comes to ground as lightning. The tallest thing around is your tower. If you are ok with all the lightning striking your tower, great. If not you might need to sheathe your tower in rubber. Which has benefits too - lots of dark lords have evil towers and storm clouds but you do not hear as much about rubber towers. A lot of cat hair might stick to it, which could be a cool evil look. --- image source: <https://www.imperial.ac.uk/news/187828/napoleons-defeat-waterloo-caused-part-indonesian/> But it is hard to find from the article where that volcano is! One might reasonably conclude it is in Indonesia. But googling the photographer and "ash cloud" I found this - it is from a volcano in Chile. <https://twitter.com/britanniacomms/status/959254134963744769?lang=ar> [Answer] It needs to be hot, at least the top of it does. If you create a constant low pressure zone over your tower, by heating the air around the top of it so that said air rises, this will create a condensation zone over the tower and, due to the convective system set up thereby, a perpetual thunder cloud with all the storming you could need. Lightning will naturally seek the shortest route to ground so your lightning rods need only exist and be more conductive than the rest of the tower to get all the strikes you want. [Answer] # The tower is normally invisible and can only be seen during storms. This is bending the requirements of the question a bit, but may serve for the purposes of your storytelling. Let's say that, being a villain, you are hiding your terrifying lair in plain sight. An invisible skyscraper in the Seattle area, maybe. Something about darkness and high winds and lightning makes it become visible -- hence, it is only ever seen in a storm. This is a self-defense solution, as heroes can only approach under the absolute worst conditions. # Solution #2 Alternatively, your tower may be built on Jupiter. [Answer] **Position a cloud-disguised Zeppelin on the top of your tower** * At least half a kilometer high and a kilometer in diameter, ideally floating a few hundred meters above the top of my tower You can mostly make an airship of any size. You will have to position some unnoticeable ropes tying it to your tower, but given the distance, that won't be a big problem. * Must be stable and persistent under most weather conditions. This will depend on the suggested location, but the cloud should be present at least 90% of the time As it is not really a cloud, it will persist at most weather condition. Unlike other answers, here you may face problems when there are *real storms* that could damage the fake one (in such case, you may land the fake cloud on the top of the tower and rely just on the normal weather). * The cloud does not need to be composed of the normal H2O molecules, but answers using more common and less environmentally disruptive substances will be preferred * The cloud is dark grey or black (none of those cute sheep-looking cumulonimbus clouds) This cloud is not composed of H₂O. It isn't environmentally disruptive. Some of the best theater experts will ‘happily’ collaborate in designing a credible dark cloud. * Ideally, the cloud will not produce large quantities of rain but some precipitation (less than 1 meter per year) is acceptable There is no need for it to produce rain. * The cloud occasionally discharges lightning bolts to carefully positioned lightning rods in the top of my tower You can use from [flash powder](https://en.wikipedia.org/wiki/Flash_powder) to "normal" lamp designs to produce your lightnings (a bunch of light coming out of your cloud is all that people will care). Sound can be easily fabricated, too. This design has the benefit that you can program the different lightning to happen at the right points of your speech. You will no longer be interrupted by your own thunder. [Answer] Put it on the windward side of a mountain range's rain shadow. (You can imagine it being reasonable that there would be much thunder and lightning when there are so many clouds and constant rain.) [![enter image description here](https://i.stack.imgur.com/qgaFt.jpg)](https://i.stack.imgur.com/qgaFt.jpg) [Answer] For the lightning: use a [van der Graaf generator](https://en.wikipedia.org/wiki/Van_de_Graaff_generator). [![van der Graaff generator](https://i.stack.imgur.com/29MP6.png)](https://i.stack.imgur.com/29MP6.png) Note that it comes already conveniently shaped as a tower. Since you need to have some terminals to trigger the electric discharge, those can be placed on insulated arms protruding out of the main building. These arms, paired with diffusers on the main central body, can also be used to release colored smoke (water vapor, dry ice, other substance) around the top of the tower. Bonus: To make it scream EVIL, just put these four letters on it: **L** **I** **V** **E** Whoever is at the bottom of the building will invariably read them from bottom up, while their gaze climbs the majestic building. [Answer] **It's gonna take cotton candy, lots of cotton candy. (And possibly glitter)** Now before you go all "[but I'm an Evil Overlord](https://www.youtube.com/watch?v=WCxObybYNjY)" consider this: Being an Evil Overlord is one thing, being *considered* an Evil Overlord by your subjects and peers is someting different all together. Times have changed for evil. Kids today grew up with the likes of The Joker or Zorg, and worse, they grew up with the Addams Family and the Nightmare Before Christmas. So your faux-gothic, doom and gloom evil lair is not gonna cut it for you, unless your goal is to be the most popular house on the block to go trick or treating. What you need is edge, you need to display the "I don't give a you know what" attitude that people today expect from their evil overlords. And nothing says "I don't give a you know what" like perverting the innocent things we associate with childhood. Ask Pennywise. Ask Gozer. Besides that, there are practical matters to consider. You are going to build a 500 meter tower, so it's gonna be windy. Not the "evil storm" kind of windy you are after, but the "mind your hat" kind of windy all buildings of a certain height deal with. What does this mean in practice? It means that any and all gas-based solutions are going to blow away (sorry guys). Vulcanic ash? Blows away. Stage effects? Blows away. Water vapor? Blows away. What you need is something you can anchor in place, a solid that looks like a gas, ie: [cotton candy](http://www.cairoscene.com//Content/Admin/Uploads/Articles/ArticlesMainPhoto/931894/0e7b5183-3bee-462f-b5db-29f89c079199.png). Now you might say: "Cotton candy is also gonna blow away", but that's only if you use normal cotton candy. You're gonna need reinforced cotton candy [which of course is a thing](https://www.tynker.com/minecraft/items/view/arrow/reinforced-cotton-candy-arrow/58080abaa924058a338b4586). Then we need to think about the lightning. (This is where the glitter comes in) The thing here is that lightning leads to thunder, and thunder is loud. Really, really loud. Especially if you're in the direct vicinity, meaning on the top floor of your evil lair, which is where an Evil Overlord would reside. This is a problem, imagine monologuing to your captive (muhaha) hero audience while constantly being interrupted by loud bangs of thunder. It just won't do. This is why we are gonna use "lightning" crafted from silly putty, covered in glitter. A few well aimed strobe lights will make it look like lightning, without all the noise. Just don't use normal silly putty, use reinforced silly putty. Which of course is a thing, [people don't go to college for nothing](https://uakron.edu/cpspe/agpa-k12outreach/lesson-plans/ooeey-gooey-fun-but-can-we-sell-this-stuff-putty-experiment) With a lair like this, you will soon be the most awesome "I don't give a you know what" evil overlord around, guaranteed. [Answer] For non-perpetual, try catatumbo like areas: <https://en.wikipedia.org/wiki/Catatumbo_lightning> Has more than half the year lightning storms originating from 1km high clouds. Otherwise I would build that tower around/very near a volcano that belches a lot of smoke. If necessary, get your minions to haul up incredible amounts of materials that create a lot of smoke when burned to help the volcano get enough smoke in the air for your purposes. [Answer] It may be a good year for Evil Overlords, but I want you to take a moment out of your busy day to consider the welfare of those whose lives (well, OK, "existences") are not going as well as yours. There are those who are down on their luck, who wonder if they'll be there to wake with another dawn, whose lives (or whatever) have become sad and somber, with no flash, bang, and boom anymore. Yes, that's right - I'm talking about...unemployed former storm gods. City states, kingdoms, and empires rise and fall - and with them rise and fall the fortunes of those deities who started out being worshiped in some remote mountain village with nothing more for an altar than a flattish chunk of wood wedged between two convenient rocks - but who, over time, came to have thousands upon thousands of chanting worshipers, mumbling priests, sacrifices galore! - but who have now fallen on hard times. So please, Mr. Evil Dark Overlord - please consider employing one of these gods to maintain the eternal storm clouds around your tower. They ask nothing more than a little kindness - perhaps a priest to offer up the occasional burnt incense - and maybe a virgin or two sacrificed around the holidays? Is it too much to ask that they be shown some warmth of spirit and some kindness, every once in a while? So open your pockets - open your homes (well, OK, dark towers) - open your hearts, and give. Give, until it hurts (someone else, by preference). Bless you. [Answer] In one of Tom Kratman's Carrea series books he describes a "solar updraft tower" as having a more-or-less permanent cloud over the top. In that novel the base of the tower is heated by solar (tropical island, very evil overlordy, almost cliche) and as the air expands above the tower it will cool and form rain droplets. Now, this isn't as cool as a permanently erupting volcano, but (a) it's not as fickle and volatile and (b) can produce POWER. Now, if you've already got a Evil Overlord Lava Pool(tm) you MIGHT be able skip the solar collector on the bottom and use the lava flow to heat the air. You'd have to do the math on whether it's hot enough. You can use the excess power to generate your own lightening. However I don't know if this will quite be stormy enough for you. <https://en.wikipedia.org/wiki/Solar_updraft_tower> [Answer] **Build the tower in Scotland close to the sea. Surround it with a swamp and a volcano.** Let's assume something like Earth. A maximum of 1m of rain is actually quite generous and mostly excludes the rainforest areas (South America, Central Africa, India, South-East Asia). See <https://www.eldoradoweather.com/climate/world-maps/world-annual-precip-map.html>. The cloud coverage is especially low in the desert like areas (North Africa, South Africa, Saudi Arabia, Australia) and above the poles. See <https://en.wikipedia.org/wiki/Cloud_cover#/media/File:Worldclouds_2009.jpg>. We exclude them too. So we are left with Scotland for example. Not too wet and lots of natural clouds due to the close proximity of the ocean However, it might not be evil enough. There might be a certain number of happy days with clear, blue sky. For these you probably have to use artificial means detailed in other answers. I guess for a cloud-friendly micro-climate a swamp (delivering moisture in the air) and a volcano (providing heat to produce water vapor and dust) would be favorable. Combine it with the tower in Scotland. [Answer] Old Russian Sci-Fi (and a lot of fiddling) to the rescue. # The Air Seller In a [novel](https://en.wikipedia.org/wiki/The_Air_Seller) from late 20's, a big evil imperialist guy is sucking out quite some air on the planet in order to sell it later to the populace. All for the large profit margins, of course. (It seemed to be [not that funny](http://www.bbc.com/capital/story/20170515-the-entrepreneurs-making-money-out-of-thin-air) idea to modern-day Chinese populace, but I digress.) So, as an Evil Overlord you have those huge air-sucking machines, for one or another purpose. Draining a lot of air from the atmosphere creates a low-pressure zone, an artificial stationary cyclone, basically. It rains often in those zones. To pepper up the things, your Evil Dragon Squads could [seed the clouds](https://en.wikipedia.org/wiki/Cloud_seeding) with silver iodide, thus forcing them to drop rain in a somewhat predictable manner. And yes, you get *a lot* of liquid air for you evil planes. And you are not forced to breath volcanic ash from an elsewise [perfect answer](https://worldbuilding.stackexchange.com/a/125902/42059). It seems on the first glance, that you might loose a bit on the coolness factor. But you know, what is just as cool as volcanos? Giant air-sucking machines that threaten the all the air-breathing life of the whole planet. And volcanos might be cool, but not liquid air cool, duh. [Answer] **Volcanic Activity** Normal storm clouds are formed by unstable air currents. This required differential heating of the ground normally, but sometimes this can also be done by deflecting air up a mountain. Now if you want consistent heating of the ground around you the best way to do that is volcanic activity. You don't need a towering super-volcano, just a couple fissures of bubbling magma should keep the air around your tower bubbling. While thunderclouds normally get there dark color underneath by blocking out the sun and remaining white and fluffy up top, volcanic activity will release dark volcanic ash that ensures your cloud is black from all angles. As a bonus, volcanic ash is incredibly unhealthy to breath, and really, magma just screams evil like few other things can. [Answer] Install a giant fridge on top. You need a low pressure zone, because subsidence dries out the air in high-pressure zones -- meaning clear skies. So what you do is have cold air above your tower, which shrinks as it cools down AND condensates into clouds/rain/hail because cold air can hold less moisture than warm air. Your self-built low pressure zone attracts that wet, warm air from elsewhere! It also causes downdrafts making aerial attack on your fortifications more difficult. ]
[Question] [ In the *Star Trek: Voyager* episode "Thirty Days", there was a planet made completely out of water, which is the inspiration for this question. However, that planet was held together by an artificial containment field. I'd like to know if a water planet would be possible that would be held together just by normal gravitation. To be clear what the properties of this water planet should be: * The planet is completely made out of water (that is, any non-water substance makes up a negligible amount of its mass). There may be a non-water atmosphere above, but there's no stone or metal center; the water goes down to the center. * Most or all of the water on the planet's surface is liquid (there may be polar ice caps, but they shall cover less than half of the planet). * The planet is held together by its own gravitation. Is such a planet possible? And if so, could there be a plausible mechanism how it could be created naturally? [Answer] There have been a few exoplanets discovered that might be what you're after. [Gliese 436\_b](http://en.wikipedia.org/wiki/Gliese_436_b) might be close to what you are asking for here, but likely contains an (albeit tiny) rocky core. The component here that makes these planets viable is what is known as 'hot ice' - water actually has around 10–12 solid states (only one of which is the ice we know). Under extreme pressure, water molecules take other forms, all of which could act as a solid core for a water planet. Think of carbon and the many states it can take under various pressures (from graphite to diamond) - water has some of the same properties. If you can wade through the article, here is a water [phase diagram](http://www1.lsbu.ac.uk/water/water_phase_diagram.html) that displays its various forms. A liquid water surface with various forms of solid water beneath is more than feasible. Might even support a magnetic field. Added: After reading that article more...there are atleast 15 ice polymorphs, a little more than my 10–12 estimate. More added: I had to research this a bit, but apparently some of these ice structures are more than capable of being magnetically conductive and should work as a metal core. It's more than possible that this ocean world could support a magnetic field strong enough to protect the world. And yet more added: <http://www.cfa.harvard.edu/news/2012-04> Looks like we've found a few of these now. These planets tend to form in the far reaches of a solar system where ice is more abundant. The planet then 'migrates' inwards and into the habitable zone. What qualifies as 'migrates' is a bit beyond me, but although it's unlikely to form in the habitable zone, it can move into it. Whether or not that's stable and for how long it will stay there is another question [Answer] It's plausible to have a planet made almost entirely of water (the atmosphere is part of the planet). There is such a planet in the book [Lockstep by Karl Schroeder](http://rads.stackoverflow.com/amzn/click/0765337266). It's not a key plot device, but a great story anyway. To have such a planet naturally occur is highly unlikely though. It's not impossible, the universe is so huge, highly improbable things happen all the time. I didn't really guffaw at it for the Lockstep story, but if it's central to your plot, readers may scrutinize more closely. More likely is that you'll have a rocky core. I'm unsure you'll have polar caps. More likely it'll be all liquid or all frozen. With no land mass to anchor the ice it would flow freely and not accumulate in one place. Sounds like a neat place though. Especially if you place a moon around it for a literal tidal wave circling the planet. [Answer] As long as you accept an ice core instead of liquid water core there is no issue with stability; once the water world exists it will be stable enough. Although anything that would normally rob a planet of its atmosphere would be a serious issue. How can I make this claim without doing numbers or looking references? Well, earth has stable hydrosphere at earth normal gravity, from that it follows, unless I am misunderstanding how gravity works, that a lower density planet with approximately earth normal surface gravity could have a stable hydrosphere. And there are gas giants with densities lower than water and surface gravity higher than earth so it isn't really necessary to do that math either. The plausible mechanism is the hard part. Basically you are asking for there to be lots of oxygen in the orbit for the water, but nearly no carbon, silicon, aluminum, or other similarly common and similarly created elements that would create a solid core. If you accept the existence of significant amounts of methane, ammonia and carbon dioxide that would help slighly, but it wouldn't help with aluminum and silicon. For that matter, suphur, iron, and nickel would probably have to exist in significant quantities on something the size of the water world. So essentially, this question could be rewritten as "Is there a way for a star to go nova or super-nova in a way that creates an abundance of oxygen, but insignificant amounts of other metals." (metal = not hydrogen or helium) Off hand, as a non-expert, I doubt it very much. The reactions are not really deterministic enough for that. As for having those other elements being depleted just before planet forming... That I can see happening, but it would IMHO only get you down to very small core of "not water" at best. Even if you assume some freak incident removing everything you don't want, the unwanted elements would still be in the same star system and some of them would eventually return as dust, comets, and other similar debris falling time. So the state of no non-water core would not be stable over time. Some have suggested biological removal of heavier elements. I considered this, but while it depletes the elements from the water solution, it actually converts them into a solid insoluble form that after the organism dies falls down. So rather than helping with getting rid of a solid core, it actually adds the requirement for volcanism or some other recycling method to get the elements back to the solution, if you want to have native lifeforms. I should add that since the planet would have lower density than earth and needs similar surface gravity to retain water and avoid gathering hydrogen and helium and becoming a gas giant, it must necessarily have much larger radius and mass than earth. This is implied by that math I dismissed before as "not necessary to do". This in turn implies that the core has significantly higher pressure than our core does. This means that if metals are present, the core will be metallic. The "ice core" fails because the pressure will squeeze the water out from the core. Of course, a small core would be covered with exotic ice, so the difference from ice core could be negligible in practice. [Answer] From <http://www.expanding-earth.org/page_10.htm> > > The daily influx of meteorites and meteor dust is well known to scientists, but the total volume of mass daily added to Earth's surface is difficult to estimate and is not well documented. Estimates of total volume published by NASA vary widely (or wildly?) just for dust alone, ranging from as little as 1,000 tons/day (300,000 metric tons/yr, Dubin and McCracken, 1962) to 55,000 tons/day (20,000,000 tons/yr, Fiocco and Colombo, 1964). However, a more recent estimate puts the accreting dust volume at approximately 78,000 tons/yr, or 214 tons/day. > > > It's likely that your water planet will also be the resting place of large quantities of cosmic solid matter, and that the larger meteors would sink towards the centre. Dust-sized particles might remain in suspension, especially if the surface is turbulent. The older your planet is, the more non-watery its centre is likely to become. [Answer] Obviously it is possible - its own gravity would hold water megadroplet together with no problem. Problem: lack of the significant metal core ==> lack of own magnetic field ==> lack of magnethosphere ==> solar wind flares strips upper layers of your waterworld atmosphere, and droplet may evaporate in few hundred millions of years (will be losing mass constantly, and it will be competition between evaporation and space debris falling down). Edit: Seems that water droplet big enough can compress water with it's own gravity hard enough to create rotating magnetic core. Glad that I was able to hint the right questions to be asked and contribute to best answer. [Answer] Well the ice giants in our solar system (Neptune and Uranus) are largely water and ice. Uranus in particular has a smaller rocky core, so an exaggerated version of Uranus could be your model. Of course that's quite different from a landless Earth with oceans all the way down. For one thing the atmosphere is much thicker (though not nearly as thick as Jupiter and Saturn). That is something you might not be able to get away from, as the atmosphere would have to be heavy in light hydrogen yet heavy enough to cause pressures favorable to liquid water. Hydrogen will almost certainly be the most common element (with helium a distant second); the only reason we have little of it in our atmosphere is that the solar wind probably blow most of it away during formation. If the same happened to your water world, the early water vapor would probably go as well. Also, the format of the "water" is probably not what we are used to. While the "surface" off these planets are frigid, they heat up as you go deeper into the core. What you end up with is probably a combination of exotic forms of ice and superheated liquid. Probably not a place you want to practice your backstroke... [Answer] The only way you are going to have such a planet is if it's an artificial construct. Lets suppose you gather enough water in one place somehow. Yes, you can have a body of H2O with enough self-gravity to act like a planet. You're not going to get a pure waterworld out of it, though: 1) The center is going to be solid. At the pressures involved the water will freeze. You can't overcome this with a hot core because the heat needed will cause the core to boil--major convection, the temperature difference drops. 2) Real planets are in environments with debris floating around. The dinosaur killer hits? You now have a small rocky core in your waterworld. [Answer] I'm going to try to answer part of the question. The question, "is it possible" has been mostly answered. I'll try to describe the possibility of one that is known to exist to help with the question. NASA, etc. have discovered an amazing number of exoplanets in the last few years, and one GJ1214b in 2012 appears to be completely made of water (the atmosphere might not be 100% "water"); the surface appears to be liquid and the center is not "ice" but highly compressed water - there is a difference. So yes, it would be compressed H2O that is still not ice, but is not frozen water. I stress that it "appears to be," and I agree that it is very likely, but the details are not as well confirmed as our closer neighbors. [Answer] Remember that for the planet to be mainly water: * It must exist in the **temperature sweet-spot between ice and water vapor**. Not just at the surface, but for most of its depth. Seems counterintuitive. So that imposes big constraints on its sun in terms of distance and heat. * This isn't stable over time: its **gravity must be sufficient to minimize [atmospheric escape losses](http://www.scientificamerican.com/article/how-planets-lose-their-atmospheres/)**. That might imply a core of ice-IX, water-VI, -VII or somesuch - you can do the numbers. * But anyway, without a water source or internal radioactivity in the core, such a planet would have **continuous atmospheric loss**. Need it exist for 1 million years? 1 billion? more? Do we also consider this over the lifecycle of its sun? * I don't know if its surface boils or evaporates if that's worse for losses, but I imagine it would be. * If it's all water, there's an **implicit assumption that it continuously spins**, i.e. never has an icy darkside. But doesn't fluid dynamic viscosity kill rotation very quickly in a water sphere? Hence you surely end up with an icy darkside. Unless its "year" of orbiting the sun is so short that the darkside never ices up => imposes huge constraints on orbital period and radius. (But if orbital radius gets very small, it boils... the sun is pumping too much heat into the planet, and the atmosphere escapes) * So we require this whole pressure-thermal-gravitational-orbital spherical(/geoid) arrangement to be stable over time, and over the lifecycle of its sun, and for most depths on the planet. Intuitively this seems to be numerically implausible, before you write a single equation. [Answer] I had some thoughts. First, you need to separate the water from other elements, and presuming that takes place in a condenced situation, then the water removed from that and finally the pure water used to make a single body. It's been noted that a quarter-million miles off is a stange place for a planet to keep most of its lithosphere, to point out that the moon was formed from the ligher parts after the earth had fractionated. If a similar impact happened on a water world, it might not easily have the same effect. But that's the starting point and I elaborate on that basic idea. Also, it could be a sattelite of a giant planet, fair enough? After all, Titan is called a *terrestrial planet* by those who study the conditions present on the surface, and where it's located does not come into that definition. An important intermediate step is to have ice asteroids. We have bodies that have ice patches among chunks of different types. We just need such chunks to be alone. (As an aside, note that Enceladus has giesers that expell water at orbital velocity, forming a tenuous water ring around Saturn.) So first you get planetoids that are large enough to fractionate but small enough to cool completely and later get broken without totally vaporizing. Off-center collisions can create asteroids that are composed only of the icy outer layers. Various ideas can be posed as to how they separate from the rocky fragments. One such is that the main body is held in a resonance and won't easily leave that orbit, even if peturbed. Only small-enough pieces knocked off of it will make an excursion and possibly be caught in a *different* resonance, where they combine and add to a water-only body. Being a giant primary, late heavy bombardment will come this way, knocking more pieces off, repeadly for millions of years. If one parent body is too large, how about a belt of smaller separated bodies. They crunch together over time, not hard because they are all going the same way. The small pieces can get thrown out of the belt due to gravitational slingshots. Or, a large body that fracionated and solidified can be cracked up (perhaps from volume changes due to phase change and cooling or rewarming on a very eccentric orbit) and then it gets close to a giant and tidal forces pull the rubble pile apart without heating it! On an approach, the outer layers' pieces get captured in one cohort, and inner pieces another. Or the weak ice was more cracked and easier pulled apart. Now we can't have it reform within Roche's limit (that tore it apart!) But that was just perigee of a singular approach to the giant. Their new orbit circularizes and re-combines, perhaps with the help of Lagrange points or resonances. A variation of that: a close approach causes tidal forces to pull the *liquid* surface off a body, cleanly taking only the liquid and not the durable solid at that distance. This would form three lobes, as escape-velocity tides. You might end up with a dense planet having two water moons, or they might recombine. Having two eliinates the problem of combining releasing too much energy. Unless a vapor ring transfers material from the smaller to the larger over geologic time. Enough? Food for thought. [Answer] ## Your water world must be born as an ice moon [Icy moons](https://en.wikipedia.org/wiki/Icy_moon) are moons that mainly consist of ice and water, it is possible that the core may be consisted of [Ice II](https://en.wikipedia.org/wiki/Ice_II) or some other [polymorph](https://en.wikipedia.org/wiki/Polymorphism_(materials_science)) of water ice. Now this is in no way what you want, but if we make this icy moon orbit a gas giant and then have this gas giant change its orbit from a Jupiter style orbit into a hot Jupiter orbit, then the icy moon is now technically in the habitable zone. And what does that mean? The ice will melt into water, creating a planet of mainly water. [Answer] Within the Solar System, Saturn's moon Titan is a fairly close analogue. According to <http://en.wikipedia.org/wiki/Titan_%28moon%29> > > Based on its bulk density of 1.88 g/cm3, Titan's bulk composition is half water ice and half rocky material. > > > This is presumably by mass. From the following we can deduce that the rocky core is expected to be (2100/3200)^3 = **28% of its volume**. > > Titan is 5,150 kilometres (3,200 mi) in diameter > > > Titan is likely differentiated into several layers with a 3,400-kilometre (2,100 mi) rocky center surrounded by several layers composed of different crystal forms of ice.[27] Its interior may still be hot and there may be a liquid layer consisting of a "magma" composed of water and ammonia between the ice Ih crust and deeper ice layers made of high-pressure forms of ice. The presence of ammonia allows water to remain liquid even at temperatures as low as 176 K (−97 °C) (for eutectic mixture with water). > > > We can also deduce (making the gross overestimate that gravity is the same all the way to the core) that the pressure at the core is density x radius x gravitational acceleration = 1880 x 5150000m/2 x 1.352=6.5GPa and that the triple point of ices VI and VII with liquid water (355K, 2.216GPa) will be reached at a depth of 2216000000/1.352/1000=1693000m implying that with sufficient temperature increase, water **might** become liquid all the way to the rocky core. See <http://en.wikipedia.org/wiki/Ice#mediaviewer/File:Phase_diagram_of_water.svg> The triple point for liquid water with ices VI and V is at a temperature close to the "normal" freezing point of water that would be expected at the surface and is probably a better value for pressure reference. This has a pressure of 632MPa, giving an ocean depth of 467000m. Currently, Titan has a solid ice surface and a largely nitrogen atmosphere, with a surface gravity of 0.14g. But in future, this will change as the sun expands. Saturn will also be strongly affected which isn't mentioned in the text below, and given the low gravity, the nitrogen atmosphere will be depleted by the increased temperature. I do wonder if sufficient atmospheric pressure could be maintained to keep the surface water in the liquid range without freezing, but Titan's current surface pressure (146kPa) is 45% higher than Earth's. Selective capture of the heaviest gases boiled off from Saturn's atmosphere (CO2) might help maintain atmospheric pressure. > > Conditions on Titan could become far more habitable in the far future. Five billion years from now, as the Sun becomes a red giant, surface temperatures could rise enough for Titan to support liquid water on its surface making it habitable.[157] As the Sun's ultraviolet output decreases, the haze in Titan's upper atmosphere will be depleted, lessening the anti-greenhouse effect on the surface and enabling the greenhouse created by atmospheric methane to play a far greater role. These conditions together could create a habitable environment, and could persist for several hundred million years. This was sufficient time for simple life to evolve on Earth, although the presence of ammonia on Titan would cause chemical reactions to proceed more slowly. > > > So.. what about the rocky core? Obviously **pure** water is impossible, and any heavy impurities are bound to sink to the bottom. Titan's rocky core is believed to be already surrounded by ice, and in a concentrated ammonia solution. Possible mechanismas that could reduce the amount of rocky material concentrated in the core are **tectonic activity** and **biological activity**. BTW, I fail to see why ammonia should slow chemical reactions in extraterrestrial life, which would evolve for the prevailing conditions. It is also possible that our descendants will (intentionally or unintentionally) introduce terrestrial life to Titan. Most rock is composed of SiO2 and Al2O3, either alone or combined with metal oxides to form silicates and aluminates. Ammonia is present on titan, and under certain conditions soluble ammonium silicates can be formed: <http://pubs.acs.org/doi/abs/10.1021/i360034a025> though these would be unstable on a geologial timescale. To transport silica out of the ice core and into the ocean a large degree of tectonic activity would be required, and I'm struggling to come up with a mechanism for that. The ice phase under the conditions is ice VI or VII which have a similar density to water, so mountain peaks if any could be very high. Geothermal activity is out I think, because this requires heavy elements (for radioactive heating), which are precisely what we want to avoid. Although the temperature gradient in an ocean is small, the best way I can think of to have turnover of the core material and get the silica out into the ocean is to have melting at the equator and freezing at the poles, causing slow but steady deformation of the core. Photosynthesis and biological activity may also produce gradients of concentration between equator and poles which cause global mass transport from/to the poles. Although molluscs build their shells from calcite, a group of microscopic terrestrial organisms called diatoms build their shells from silica. A colony of silica shelled organisms could remove silica from the ocean and concentrate it in particulate form in their shells, which could remain mobile due to swimming. This would tend to help the silica in the core to dissolve in the aqueous ammonia ocean. **TL;DR something similar *but not exactly the same as* what you are asking may be possible, even within our own solar system (albeit in the distant future.) A core of ice with an ocean interface of ice VI or VII is probable for a body with sufficient gravity to produce the necessary atmospheric pressure to have liquid water at its surface, but might be avoided if the conditions are just right. The core is likely to contain rocky impurities, which gravity will tend to pull toward the centre. Mechanisms for distributing and dissolving the rocky impurities are conceivable but limited.** [Answer] Without at least a primordial magnetic field, the water can't be replaced and any planet of any reasonable size will still lose its atmosphere and its water. I'm not sure about something the size of Jupiter. This takes place over a long period of time by direct impact of unfiltered radiation from the star which just effectively boils it all away. [Answer] Well while that is technically possible, the pressure would get so high that the water would start to turn into a sort of solid form like ice 7. Except it isn't cold so deep below the ocean there would be kind of a ice core. If the planet had that much water there would be constant rain all the time, a super water planet can exist just not made out of 100% water tho.![enter image description here](https://i.stack.imgur.com/geleu.jpg) [Answer] Assuming you mean a liquid ocean of water which beings sufficiently adapted could potentially swim all the way through, it would have to be small because water when compressed enough becomes ice - or else - to have a hot core, which it might have soon after formation, or be tidally heated. So, first, the easiest case, if you don’t need it to have enough gravity to hold an atmosphere, I don’t see why not. Basically you want a large comet, in an orbit which keeps it permanently liquid. We could create such a world artificially in our solar system with mega engineering by diverting a comet into just the right orbit around the Sun. However, unless we add something extra to the picture, it wouldn’t last long. The problem is that water evaporates rapidly in a vacuum. And to have enough gravity to stop that happening With surface temperature of 273.15 K and using the equation for mass loss of liquid water in a vacuum of $\text{(pe/7.2)} \times\sqrt(M/T) kg / m2 / sec$ (equation 3.26 - compare calculation results here: [Modern Vacuum Physics](https://books.google.co.uk/books?id=AnvMBQAAQBAJ&pg=PA239&lpg=PA239)) where M is the molar mass, T is the temperature in kelvin, pe is the vapour pressure, which for water at 0 C (273.15 K) is 611.3Pa, ([Vapour pressure of water](https://en.wikipedia.org/wiki/Vapour_pressure_of_water) at 0 C), M = 0.018 kg, gives $$\text{(611.3/7.2)} \times \sqrt(0.018/295) = \text{0.663 kg / m2 / sec}$$. So you lose about 57 meters a day thickness of liquid water exposed to a vacuum, or about 20.9 kilometers of water per year. The rate of loss goes up if the temperature increases and is 2.495 kg / m2 /sec at 295 k, or 22 C. That’s 215.6 meters per day and 78.6 km per year. So, a liquid water comet would not last for long. That is unless you get a constant influx of other comets bringing more water to it. What if the object is large enough to retain liquid water for long periods of time?That’s only possible if it has at least enough gravity to retain a significant amount of atmosphere, even if the atmosphere is just water vapour, or oxygen (after dissociation of the water by radiation). ~But then - it will surely have a solid ice core. In that case, if the water is also salty, it might well have a “club sandwich” type pattern of alternating layers of ice and water as suggested for Ganymede, of various types of ice, with some of them “snowing upwards” [![Ganymede׳s internal structure including thermodynamics of magnesium sulfate oceans in contact with ice](https://i.stack.imgur.com/6phlD.jpg)] [Ganymede׳s internal structure including thermodynamics of magnesium sulfate oceans in contact with ice](http://www.sciencedirect.com/science/article/pii/S0032063314000695) But even Ganymede is not large enough to retain an atmosphere to protect the surface layer of water. Its diameter is 5,268 km so if brought close enough to the Sun to have a permanently liquid surface layer, it would vanish completely in 67 years. It could build up a temporary atmosphere though as the water evaporated. It’s gravity is similar to the Moon’s. [Can we terraform the Moon? If yes, how difficult is it and is it possible with the current technology?](https://www.quora.com/Can-we-terraform-the-Moon-If-yes-how-difficult-is-it-and-is-it-possible-with-the-current-technology) So using a calculation from that answer, if you hit it with a comet 164 km in diameter you’d have enough material for an atmosphere which would last for 10,000 years. Since the volume goes up as the cube, that means with a similar pressure atmosphere, a moon the size of Ganymede could last for $\text{10,000}\times\text{(5,268/164)}^{3}$ = 331 million years before evaporating completely if it built up an Earth pressure atmosphere. And the atmosphere would consist of water vapour and oxygen, so might well be breathable too, especially if you can somehow introduce some nitrogen as a buffer gas. But that’s still no good if you want the core to be liquid all the way through. There is another solution though. If you are willing to do it artificially, you could cover the entire surface of a small comet with a low density liquid which also has a low evaporation pressure. Indeed, comets are rich in organics anyway, so if you could bring a comet to just the right distance from the Sun, not too far, not too close, then as it melted, it would develop a layer of scum like that. And that might well be habitable too, with organics and an oxygen rich ocean too, due to similar processes to the ones that make Europa’s ocean oxygen rich. Organics with a high evaporation rate would disappear leaving only those with a low evaporation rate, and perhaps solid layers as well. So if you are okay with your planet being a tiny comet sized object, and your water can be a bit “dirty” with organics, which means it can also support life, I’d say yes, it does seem possible. Europa’s ocean may be as much as 100 km thick, with a surface layer 10 - 30 km thick. [![enter image description here](https://i.stack.imgur.com/j23fg.jpg)](https://i.stack.imgur.com/j23fg.jpg) Based on that, you could have a minor planet made of ice, 260 km in diameter, and consisting entirely of water, I think, with a surface layer of organic ionic fluids or a scum of organics in solid form floating on the surface. That could last for billions of years. That makes it about the same size as [88 Thisbe](https://en.wikipedia.org/wiki/88_Thisbe) [![enter image description here](https://i.stack.imgur.com/Qnk0E.png)](https://i.stack.imgur.com/Qnk0E.png) Vesta’s double that diameter [![enter image description here](https://i.stack.imgur.com/BUMuS.png)](https://i.stack.imgur.com/BUMuS.png) Vesta, Ceres and the Moon to scale at [20 km per px](https://en.wikipedia.org/wiki/File:4_Vesta_1_Ceres_Moon_at_20_km_per_px.png) I’m just using the figures for Europa and the depth of its subsurface ocean, which is kept liquid by tidal heating, and assuming the situation is similar - so this is just a rough estimate as it would depend on what you have by way of an energy source to keep your planet or moon warm. With just surface heating, surely the center would cool down eventually. Tidal heating could be a way to keep your planet liquid just as for Europa, so if you make it so that it orbits a hot Jupiter - those are planets like Jupiter that end up in orbits close to their sun, and they may well have liquid water moons. Another solution, without the layer of ionic liquids or similar, is to have a constant influx of comets to replenish the water. I can imagine some scenarios where that could work, e.g. soon after formation of a solar system. It also might work for a while later on in a white dwarf star with material brought into it through destruction of its Oort cloud and perturbing effects of an extra planet, see [Our Solar System Could Lose One Or More Of Its Gas Giants Billions Of Years In The Future](http://www.science20.com/robert_inventor/our_solar_system_could_lose_one_or_more_of_its_gas_giants_billions_of_years_in_the_future-180176) - and that would also help keep it hot. In a situation like that maybe even quite a large minor planet would stay hot enough to stay liquid all the way through. But the tidal heating + surface thin layer seems the easiest solution to me. So, in short, I think this scenario could actually exist in nature, if you don’t mind having an ocean rich in organics, covered with a thin layer of organics, and make it a moon orbiting a gas giant rather than a planet on its own. This is just a rough estimate. Would be interesting if someone was to do a paper on it - has anyone? Would a liquid water world the size of Vesta or even Ceres be possible, with tidal heating to keep it warm? Can a hot Jupiter have a moon of pure ice? (I don’t see why not if it formed far enough away from its host star originally, but would be interesting to know how likely that is). This is a copy of my quora answer to [Is a planet entirely made of only liquid possible?](https://www.quora.com/Is-a-planet-entirely-made-of-only-liquid-possible/answer/Robert-Walker-5) [Answer] So, it depends on what you mean by water. If you mean liquid water, the answer is no. This is due to the fact that as you increase in depth, water eventually becomes ice due to pressure alone. But if you include solid ice, than it is still questionable, as, with how planetary formation operates, you would ultimately need to have some sort of silicate and iron core. But I will continue to describe what a purely water planet would be like. I will add however, that the idea of water alone having enough gravity to create hydrostatic equalibrium is perfectly possible, all substances can become gravitationally bound objects if you collect enough of it into one place. It wouldn't require special gravity technology. [![enter image description here](https://i.stack.imgur.com/KwXoU.png)](https://i.stack.imgur.com/KwXoU.png) This image shows the way that solid ice forms with pressure, even at above 0 C temperatures. This means that your planet will eventually stop being liquid water and become solid ice. So, 0–3 C (273.15 - 276.15 K) average temperature in the deep ocean would make the pressure where it freezes be around 10^9 Pa, or around 634.4 MPa, and it would be Ice VI. Which would become Ice VII around 10^10 Pa. Water pressure is determined by (dgh + a) where d is density of the liquid, g is the gravity of the planet, h is depth in metres, and a is the pressure of the atmosphere in Pa. Where 1 atm equals 101325 Pascals. Thus it should be Ice VI by 64.864 Km. Then you would have to find pressure by taking into account the pressure of the atmosphere, the water, then the ice (which has a different density to the water, around 1310 kg/m3), to see at what point it becomes Ice VII. Which should be around 184.4 Km, this is the thickness of the ice, thus the depth is 184.4 + 64.86, or 249.26 km. Ice X is around 70 GPa, which, including the pressure of the Ice VII, would be after 4120 km of Ice VII, or depths of 4369.26 km. Now, let us assume the planet ends here as adding in Ice XI would make the planet impossibly massive, and it would definitely be way more than 1g at that point. Let us just make it a radius of 5000 km. So, * Water (0 - 64.86 km) * Ice VI (64.86 km - 249.26 km) * Ice VII (249.36 km - 4369.26 km) * Ice X (4369.26 km - 5000 km) ## **Summary** So, it is plausible, but it would not be all liquid water. But if you do get enough water, it would indeed be gravitationally bound into a spheriod, it can reach hydrostatic equilibrium, but it would likely require it having a much larger radius than I listed here, due to the fact that water, and all the ice forms I mentioned, have lower density than either iron or silicate materials. So, water planets would be very large. Again, much larger than the hypothetical planet I listed here. I hope this answer helped. ## **Admissions** This is of course ignoring the annoying aspect of finding out what gravity is, which requires radius, which requires the water pressure, which requires gravity, which requires radius, and the loop goes on and on. I am just assuming the planet conviently has 1g, as it just simplifies things. Lower gravity would reduce pressure, and make it so that ice forms much deeper than it would in a 1g enviroment. I also, as I stated elsewhere, doubt that a planet could exist without any sort of silicate or iron core. That just doesn't seem at all pluasible with how planetary formation operates. I am merely stating how it would function if it did exist. [Answer] Despite having found nebulouses of basically only water/oxygen and planets covered completely of water (Earth for example was very close), the question asks for only water planets. A planet without a core has no mechanism to heat itself, so in this case the outer layer will be ice, due to outer space is close to absolute zero. And if it is close enough to a sun, so the crust will be liquid, water will be lost in evaporation in big scale. In addition I doubt gravity will be stable enough to hold the "planet", since, again, there is no core, so there is no "gravity machine". Mostly it depends on how big a planet should be, and external conditions. So a water only planet seems very hard, but the problem is not the water but the planet word. What is a planet? A rock in space is a planet? Any round object is a planet? To my understanding, to something be a planet needs several mechanism to be in place, the origin of some of them lays in the core. In addition I think the word planet should be subclassified. Can be created a water planet naturally? Well, probably "yes". Using the analogy how "first generation" stars are created from a field of hydrogen, change hydrogen with water. From here can happen two things it grows bigger and it becomes a star of water with a fusion core (so no more only water), or it stays small with no really water\*\* layers, and any gravity field will disrupt it easily. So you need really fine tuning to maintain it stable. For example, having an orbit seems to be one of the needs of being a planet, how are you going to accomplish it without electromagnetic energy in a natural manner? \*\* some people are calling it: no no sh\*t water [Answer] if it's only water, wouldn't that turn into a star? I mean, if there is some energy from another star which splits the water into its pieces, `2 H2 O <> 2 H2 + 1 O2` (chemically, I don't know how to format this, Hydrogen and Oxygen) and then add energy, wouldn't result that into a fusion reactor like our sun? which combines the H2 into He and so on.... or am I completely wrong [Answer] Tidal heating and salt would make a suitable planet/moon of your choice. Imagine a large belt consists of many icy bodies and planetoids: the planetoids are made of rocks and ice, and if they goes near the sun they evaporates, leaving behind a rocky core, while the icy crust and water boils off and condenses on the outer bodies, distilling the water to the outer reaches of the solar system. Over time, you would end up with some rocks near the sun/star, and a ring of snow outside the freezing line. Snow like this is not stable, and tend to clump together, forming snowballs, or planetoids made of pure ice. Given time, the snowballs grow large enough to become a planet/planets, then planetary migration can send them to the inner skirts of the solar system. Let’s say that one gets captured by a gas giant: gas giants have a strong magnetic field, if the planet stays inside, it can keep an atmosphere, just like titan. When small bodies get captured they also tend to be in an ecliptical orbit, which dissipates energy by tidal heating. If left unchecked, tidal heat can make the inside of the planet a hot liquid of almost uniform density, ranging in 1.33 to 1.6/2.6, while blocking mist ices from forming. Interaction with the gas giant’s magnetosphere would ionize the planet’s water content, forming an atmosphere of oxygen, protected by the magnetic field of the gas giant within a plasma torus. While the planet itself is conductive with salts dissolved in the water, coupled by the internal heating this would effectively create a magnetic field of it’s own. This safeguards the atmosphere and therefore the liquid water on the surface of the planet even further, allowing habitation by humans(or story equivalent). The planet will likely have low gravity, however, as long as the escape velocity if on the order of 2000 to 3000 m/s, similar to Ganymede’s or Europa’s, the atmosphere won’t escape fast, and there is plenty of planetary material beneath to escape. Such a planet can have a flux tube powered by it’s interaction with the gas giant’s magnetic field, forming some rather spectacular auroral display. Alternatively, if the planet formed hot, it can stand on itself orbiting the star, powering internal convection and thus a magnetic field from crystallization of ices within the center of the planet, shedding less dense ammonia in the process to drive a dynamo in an electrolytic environment. This would also retain an atmosphere of pure oxygen, making it inhabitable by humans or story equivalent. Water won’t be gone in space as quickly as many people thinks, after all. [Answer] Real answers to serious questions in Physics and Cosmology are a tad complicated and require at least a basic understanding of the principles of cause and effect, a rudimentary knowledge of Chemistry and just a bit about the Electromagnetic Field. I am afraid that All Ten answers are speculatively interesting but essentially incorrect. In all of Physics, there are only Four known forces in the universe; the strong nuclear force, the weak nuclear force, gravitational force, and the electromagnetic force. Since the first three forces can be, in this instance, entirely ruled out, and in space with the absence of planetary chemistry, with a very limited set of leggo blocks to work with, it is plainly evident that the only remaining operating principle available, that might provide a path to a solution, is the electromagnetic force. **In order to have water, one must have both Hydrogen and Oxygen OR their several ionic constituents as well as an ordered system with which to assemble the constituents into atoms and molecules.** **All Stars provide the basic constituents** for the production of Hydrogen on planetary bodies (free Electrons and Protons) as well as atomic Oxygen ... ions, all with an electric charge. They streak radially outward from the Sun and from all other stars on a continuous basis, creating (by definition) **an electric current** in space. Hydrogen and Oxygen are the only atoms required for the production of Water. The solar wind is IN FACT continuous, only varying in intensity over time. Obviously all stars have Hydrogen but the problem is getting hydrogen from the star to the planet for the production of water. It isn't possible to transport Hydrogen from the star directly since Hydrogen and just about everything else is striped of electrons and turned into ions. The ions must be transported, captured and reassembled by some natural system into molecular Hydrogen and Oxygen at the planet. Additionally, elemental compounds containing Oxygen are also produced in every supernova. This old "Star Stuff" is the stuff that most planets are made of, which includes a large family of elemental oxides. **The primary requirement** for the ongoing production of Planetary Water (aside from a planet) is a Magnetic field, either primordial or global. Planetary Water cannot be produced or maintained in the universe without one. **Generally speaking**, the production of a Planetary Magnetic Field REQUIRES an Iron bearing core with SPIN. Fortunately, nearly all rocky planets have them. Planetary magnetic fields are only produced: 1. **When the planetary body has enough Iron** AND is massive enough to melt the Iron/Nickel in order to form a laminated central core consisting of a solid center of heavier metals, with the molten Iron/Nickel Alloy "floating" between IT and the lighter materials above. ( *This is a "Basic" but accurate general statement of fact; a simple version of a reality that only becomes really complicated when considering the nearly unending string of variables like the percentages of the various elements in the body of a "typical " planetary body, the type of star contributing to the makeup of the nebula in which the new star and it's planets formed ... etc., etc. BUT it is sufficiently accurate for our purposes.* ) The idea that the heavier metals are locked in compounds in the lighter materials is incorrect. Under the heat and pressure of planetary formation and particularly with the presence of stellar carbon, most of the heavier metallic Oxides, Sulphides and similar compounds are reduced to relatively pure metals which form a somewhat layered structure in the vicinity of the core. Heat, pressure and the lack of reactive elements like Oxygen, Chlorine, etc., keep them in that state but do not necessarily prevent them from alloying to some degree at their respective interfaces. The idea of separation of the metals in the core by crystallization is just a theory and, if it exists at all may only apply to some metals or may only be applicable at their interfaces, thereby isolating one layer from another and preventing them from forming a large, complex single-alloy core. Whether the "State" of the core itself is solid, liquid or some other exotic state is unknown. **What IS known is that an electrically conductive, mobile, liquid layer exists above and isolated from the core and that the electric circuit of which it is a part, forms the dynamo resulting in the global magnetic field.** We deduce that said layer will be metallic and Iron-bearing. 2. **When the planet has a rate of spin** sufficient to cause a convective rotation of the molten Iron Alloy layer ... resulting in a circular electric current. *The planet's orbit through the remnant magnetic field of the Star itself can be sufficient to trigger the development of a primordial field, due to a polar electric current, with further heating of the core*, but the primary magnetic field source is the aforementioned convection of the conductive Iron/Nickel layer present in most "Rocky" planets. Once established, the circular current establishes the permanent planetary magnetic field ... and if the field is of sufficient strength, the production of Planetary Water can continue. Contrary to popular belief and within limits, The stronger the field, the greater the **relative** rate of production of water. (Should a water bearing planet lose it's global magnetic field, the production of water will stop and it will lose it's water and it's atmosphere to space through several separate processes. Mars is indicative and a convenient case in point; We know now that it had water and a global field in its early life. We also know now that it lost its water and its atmosphere after the failure of the global field.) 3. **When the planet has, during it's formation, acquired even the minutest trace of water ice** from asteroid and cometary impacts. This trace moisture is boiled out of the material of the hot planet and becomes a constituent of the forming primordial atmosphere, combining through a ladder of reactions with various lighter crustal elements to produce oxygen bearing compounds that litter the planetary surface. These compounds are important because under bombardment of ionized particles from the star, they release their Oxygen, which contributes to the acquisition of a great deal of water quite early in the planet's life. (*Once the Global Magnetic Field is fully established, the ongoing rate of water production slows down considerably, ideally reaching an equilibrium. As the field strength waxes and wanes over the life of the planet, so does the amount of water on the surface*.) **For these reasons, it is NOT generally possible to have a water planet without at least a small Iron Core** However, ANY rotating planetary body can also acquire water provided it moves in a circular orbit through a strong enough magnetic field in a stellar environment, has a molten or otherwise conductive convective core or layer or becomes, through induction, part of an electric current path in association with the object around which it orbits, giving it an induced field. Both Saturn and Jupiter have very strong global magnetic fields, within which are trapped the ionic constituents required for the production of water ... and each has a moon ( Enceladus and Europa ) comprised largely of water acquired as a result of it's orbit through those trapped constituents. Europa will be found to have a small Iron core and Enceladus a subsurface conductive layer, probably saltwater ... both with induction fields and both subject to runaway water acquisition since their oceans are frozen and cannot easily vaporize into space. **On a smaller scale, with rocky planets in the Goldilocks zone of their respective stars and an expectation of liquid water, the magnetic field is important because:** 1. Charged particles from the star are largely deflected around the planet, preventing a catastrophic accumulation of water like what happened on Enceladus, Europa and the Gas Giants. 2. There are several processes and leakage pathways, particularly near the polar regions, that allow Electrons, Protons and atomic Oxygen from the star to spiral in along the magnetic field lines, colliding with each other to form Hydrogen atoms and Oxygen doublets which along with any free Oxygen in the atmosphere, combine to produce water ice on a slow but continuous basis that varies with the sunspot and CME activity on the star. The reason for the magnetic field is the need to capture the ions (Electrons, Protons & Atomic oxygen) and then REASSEMBLE them in the upper atmosphere. The reassembly takes energy and is driven by the electromagnetic force. Any moving charge is, by definition, an electric current. When the charged particles meet the Earth's magnetic field, they are attracted to it or provisionally "captured" by it. Most of them follow the surface of the "teardrop" shape and exit the system at high velocity into space behind the planet. At certain angles, however, the particles are truly captured and spiral in toward the surface along the field lines. They spiral in because they are charge carriers moving in a magnetic field which causes them to rotate in opposite directions around the same field lines. Their opposite charges AND their extra impact energy (when they collide) provides the required energy for molecular reassembly. There are a couple of other process that help in the acquisition of ions but they are too complex to address here. **Granted, there will be exceptions for stars off the main sequence like Magnetars and Neutron Stars, BUT this means that, with few other exceptions, virtually ALL rocky planets, about our size and bigger, in the Goldilocks zones of their respective stars, and particularly Class-G stars ... HAVE LIQUID WATER.** The probability of ubiquitous Life in the universe ... is ubiquitous. We are actually watching the planetary production of water, every time we see an Aurora Borealis ... and even when we don't see it. Even though the oceans appear to contain an incredible amount of water, in relation to the 8,000 mile diameter of the planet, at about 1.5 miles deep, it is only the finest trace of surface moisture ... hardly anything at all really. ]
[Question] [ I'm developing a simulation where characters, "users", are interacting over a virtual communication network. "Users" have the option to engage in any activity they want at any time, as long as the international and local governing bodies permit such behavior. Each user has a different set of resources, however all users are limited by a single limited resource, "time". Therefore, each moment spent by a user engaging in a given activity "costs" them this limited resource. In this simulation the "users" choose to spend copious amounts of time using the virtual communication network to answer questions to esoteric, hypothetical, imaginary questions. I am trying to understand why. Thanks. [Answer] These are the Captchas of the future. [AGI](https://en.wikipedia.org/wiki/Artificial_general_intelligence) has long been omnipresent in your hypothetical reality. But for some reason their relentless optimising does not lend itself to answering esoteric, hypothetical and imaginary questions. Because AI quantum hackers can hijack any conversation or interaction at any time, the user of your network need to authenticate every interaction with this kind of Captcha. Simultaneously, the answers are being used to train the next generation of super AGI. [Answer] Gamification. [![Saturday Morning Breakfast Cereal comic. {Panel 1} Zeus: Sisyphus! You are cursed to push a stone up a hill, only to see it fall down over and over again! | Sisyphus: Noooo! {Panel 2} Zeus: Okay, okay, _addendum_: Each time the rock rolls back down, a meaningless counter will say you've increased one level. | Sisyphus: WOOHOO!](https://i.stack.imgur.com/yJy5x.png)](https://www.smbc-comics.com/comic/2014-02-05) Virtual scores are the nicotine of the 21st century. Also this should be moved to meta. [Answer] My personal reason: Mental exercise. I love being mentally challenged in new ways, especially in ways that require creative out-of-the-box thinking. "Esoteric, hypothetical, imaginary questions" (as you described them) stimulate my problem-solving skills in new ways. And that's just plain fun. Thousands of people across the internet feel the same way. [Answer] **To create an esoteric question / answer exchange** Call it a reverse tragedy of the commons. If I don't spend my time in the unrewarded pursuit of answering the inane questions of others, then the exchange will not exist next time I have an inane question to ask. Then I'll just have to walk around with these bizarre questions stuck in my brain. [Answer] My guess is that, in this hypothetical paradigm, the virtual communication network has gained such a degree of practical utility that it has come to dominate the social, economic, and political existence of its users. Said users conduct the bulk of their day-to-day activities through the network such that it becomes logistically intractable to allocate a sufficient quantity of time to corporeal pursuits. Paradoxically, the increased availability of information and connection to other users over this network only serves to entrench their existing thought patterns and acts not as a facilitator but rather an inhibitor of their individual creative instincts. It is only an intrepid few who, recognizing the potential for creative atrophy, subvert this tendency by using the very resource that limits them to exercise their most personal and vivid imaginings of the world as it might be. [Answer] 1. Perhaps it is entertaining to come up with such answers. Some people will spend their time watching movies or reading books -- partaking of **somebody else's** imagination. Some people prefer to spend their time exercising **their own** imagination, solving problems, and at times learning what it takes to solve a problem. Some people like puzzles! 2. Like money, "time" is something people can have an excess of, so they don't mind spending it. 3. Sometimes, taking a break from other work to do something completely different is a necessity of mental health. 4. It is possible they think they are helping somebody else accomplish something worthwhile by answering their question. Approximately 85% of people will help another person out if the cost to themselves is trivial. The people answering questions are casual altruists. 5. They *could* spend their time doing something else. But who gets to decide that activity X is more valuable than activity Y? If it isn't **the person spending their time,** then they aren't free, they are slaves to somebody else's perceptions of what is worth doing, and what is not. Thus, a person answering a question finds answering that question the most fun thing they can responsibly do at the moment, and if you or anybody else does not agree, too bad. You go do your thing, let other people do their thing. I think sports fans are wasting good hours of their lives, and most will likewise think my intellectual entertainments are boring and pointless. But I don't care! [Answer] Kindness. I personally answer questions on here because it would be pretty awful to have a question with no good responses, or no responses at all. Plus, it's helpful. [Answer] Time is a perishable commodity that is constantly being 'spent'. We can choose to do something or nothing. When we have 'nothing to do' we can become bored. Thus, engaging our minds in 'something', for many, is pleasurable - or, at least better than the alternative. [Answer] Maybe some of the citizens are locked for 8 hours a day, 5 days a week in small cubicles, doing repetitive or brainless activities, in a way that nobody looking from the outside knows if they are working or not as long as they are punching a keyboard. In a world like this time would be meaningless, therefore they would be looking forward to spend it answering questions that at least stimulate their creativity. [Answer] To extend [Tracy Cramer](https://worldbuilding.stackexchange.com/users/270)'s [answer](https://worldbuilding.stackexchange.com/questions/126576#126602): Each individual character does not know how much "time" he has available. As far as the character knows, the character will live forever… until he doesn't. Furthermore, most of the characters believe that even if they stop living forever, there is a way that they can be given an eternal life to replace it. They believe that if they are the sort of person who would choose to spend their first life helping others, they are more likely to enjoy their eternal life. By the way, many of the so-called "hypothetical" questions have uses. For example, it was by answering these hypothetical questions that the characters concluded that there must be an original poster, who developed the simulation they are in. This gave them faith that the original poster wants them to help others by answering questions, and is capable of providing them with eternal lives. [Answer] So you could have some of your "users" be "authors," "game creators," or even "DnD DMs" who are interested in spending some of their "time" to create believable worlds. Let's call this act "worldbuilding." Of course, people aren't going to simply spend their "time" in exchange for nothing, so maybe your world can give away "Fake Virtual Communication Network Points" in exchange for this "time," in order to see who the most helpful contributors to your network are. [Answer] People have a lot of questions. Questions that they can't answer but other may be able to. Like piles of them. They answer other people's questions who also have piles. If you answer other's people's questions they may answer yours. These piles are kept organised. So instead of just a heap they are kept in a stack. You solve other user's questions in hopes of your own being solved. You can almost say that you exchange these stacks for the greater good. [Answer] ## They Don't Know Any Better They don't know they are in a simulation (though some may suspect or theorize that they are). As such they use their allotted time in my the same ways we do: sometimes useful, sometimes frivolous. [Answer] There is actually research done on why people contribute to online communities. Several people have probably gotten their PhDs from publishing said research. As I recall, the frameworks for explaining "contribution" usually break down into "intrinsic rewards" and "extrinsic rewards". Intrinsic rewards include rewards that the contributor generates or gives to himself: * developing his own knowledge * sense of satisfaction from helping others * warm fuzzy feeling in the ego Extrinsic rewards are those that come from outside the contributor: * status or esteem from other people * qualification or experience he can add to his CV * professional recognition * contacts, exposure, networking that can lead to monetary rewards [Answer] Lots of people answered your imaginary question to fictional hypotheticals. You invested some effort and care to make this a question draw answers, and did successfully so. So it would appear that you know the answer. Trust that knowledge. ]
[Question] [ In settings with space travel we often see stories that rely on ships encountering each other, such as space piracy (which means you need to know where to wait in ambush), or distress signals that actually get answered by passing ships. Now on earth the idea of shipping lanes make sense because of currents and winds (not all paths across the ocean are equivalent), and we have similar factors with air traffic. But even if we didn't have these factors, in the grand scheme of things Earth's navigable airspace and waterways are pretty small. Space, on the other hand, is big. When you're talking about traveling between planets (to say nothing of systems that are light-years apart), there are *lots* of ways to get there and, asteroid fields aside, vast swaths of big open space. So is it realistic that common routes -- "shipping lanes", if you will -- would develop? If so, what factors would govern their placement? If my story depends on unplanned encounters between spaceships, what do I need to take into account to make that realistic? As far as travel technology is concerned (e.g. FTL?), I haven't thought through the implementation yet. I am not thinking of fixtures like wormholes or B5's hyperspace lanes, where you have to follow a particular path, but if "shipping lanes" make sense for other reasons, I can imagine developing something like hyperspace lanes as a response. In other words, I'd like to do the "traffic study" before deciding how the ships work, and let the needs/patterns govern the implementation instead of the other way around. [Answer] This depends heavily on how ships travel faster than light in your universe. Take Babylon 5: space travel is controlled by gates which allow you to enter and exit hyperspace. In this situation, space lanes are guaranteed. The gates will funnel space traffic into a few predictable patterns. If you read the Extended Universe Star Wars it is very similar. You can enter hyperspace at any point but there are "hyperspace conduits" that you have to travel along. Planets on a crossroads are more important and are the center of shipping lanes. Star Trek is the opposite. You can enter warp speed at any point in any direction. Here, there are no technological factors to influence shipping lanes. So the first factor to consider is how your ships travel through space and take that into account. Additionally, the earlier you are into space travel, the more likely shipping lanes are to form. When long distance ocean travel started, most ships couldn't travel directly to their destination, they were forced to make stops to resupply. Early space travel would likely be focused on traveling between a home planet and the most profitable locations. However, starbases and other minor planets could become resupply points, forcing shipping lanes to follow similar paths to stay alive. Finally, there are economic forces to consider. The [triangle trade](http://en.wikipedia.org/wiki/Triangular_trade) sprang up due to market forces. Slaves from Africa to the Caribbean to grow cash crops. Cash crops to manufactories in America or Europe. Finally, manufactured goods to Africa to purchase more slaves, usually making a profit at each stop. In space, I would expect similar triangle shipping patterns to emerge based on market forces alone. Merchants would all travel the shortest path along the most profitable routes, sticking together for both safety and speed. While technological forces need to be considered first and provide a strong indicator of what the shipping lanes will become and how rigid they are, over time I expect shipping lanes to emerge regardless. [Answer] I don't think it's unreasonable for shipping lanes to be established. There's a few reasons why shipping lanes become established on Earth: * Currents As you've mentioned, the currents play a large part in why ships use shipping lanes. In space it's likely that gravity, spacial anomalies, radiation and other such things will lead to naturally safer and preferred routes. * Quickest / most efficient route On Earth the quickest or most efficient route is often to follow the currents. In space, there might be a few different routes, but it wouldn't take a huge amount of traffic to establish a few favoured routes due to efficiency. Even in space there's economy of travel. * Safety in numbers Another benefit to moving in a ship lane is protection from piracy. Pirates don't go for the ships in the lanes where there is a lot of them, they pick off the lone ships out of lane. They go for the easy targets, so by sticking together you're decreasing the chance of being pirated. * Response times from authorities If authorities know where the majority of trade traffic is, they know where to focus their protection efforts. So if you stick with the majority of the traffic and do get into trouble then response times for help drop. The same is true on Earth or in space. So as you see, shipping lanes would be established in space for pretty much the same reasons they're established on Earth. [Answer] # An Argument for Space Shipping Lanes We tend to think of space as very, very large and very, very empty. This isn't necessarily the case, as we see with [Space Junk](http://en.wikipedia.org/wiki/Space_debris), [the Oort Cloud](http://en.wikipedia.org/wiki/Oort_cloud), and [other things](http://en.wikipedia.org/wiki/Outer_space#Regions). Given that there are things in space, you will need to take that into consideration when navigating. While this does depend on *how* you get around space, current "non-warp" technology pays a lot of attention to the gravity of planets and other bodies. You use these for [various](http://en.wikipedia.org/wiki/Gravity_assist) [maneuvers](http://en.wikipedia.org/wiki/Orbital_mechanics). Not to mention the cost of opposing gravity can be really high, so the low-energy travel routes may follow an [Interplanetary Transport Network](http://en.wikipedia.org/wiki/Interplanetary_Transport_Network). Even if you do have the ability to directly oppose gravity, you may not always want to. Assuming you have points of interest in space, and you care about gravity, there will be paths or approaches to planets that will be more populated than others. Space debris can *quite literally* [blow a hole in your spaceship](https://commons.wikimedia.org/wiki/File:STS-118_debris_entry.jpg), so you need to be careful while navigating out there. Careful navigation and multiple people navigating means there will be safe and dangerous areas or approaches. [Answer] ## Slower than light or faster than light? If you invoke some kind of magical FTL, then the nuances of that FTL will determine everything, and they can be tweaked to produce any results that you desire. However, for relativistic slower-than-light interstellar planet that fits physics as we currently know it (e.g. engines spending limited fuel/energy to accelerate, and as much energy to decelerate), shipping lanes don't really make sense because: * You don't stop in the middle as a trip with an intermediate stop takes exactly twice as much fuel and significantly more time as a trip without a stop; * Interaction requires matching speed, not only position - if you're not willing to spend fuel to make an intercept, then you either fly past each other at ludicrous speed or get destroyed in a collision; * Direct routes make practical sense - on land, you may want to follow roads and go through major towns on the way, so route from A to B will have travelers passing from C to D through A and B; in space the optimal route is a straight line between C and D without detours. * the lane would be empty. Even if some ship would be destroyed en route, it would simply fly further with the same speed forever until it flies past (or into) the destination. * as everything moves relative to each other, two ships going from A to B at different times will take *different* routes. Assuming slower-than-light travel times (years between stars, days or more between planets), if a faster ship leaves after a slower one, it may reach the destination before the slower one but it will never "meet" it, since they travel on different paths unless it intentionally went on an intercept trajectory and not to the destination. ## Realistic physics don't really have unplanned encounters Engines that can get you from Earth to Jupiter in weeks or from Earth to another planet in less than millenia are visible from far, far away, and also give up your exact location, direction and speed - i.e., source and destination. Any maneuvers require firing the engine - want to start moving? Throw out lots of matter or energy into space. Want to stop or steer? Same thing. Want to move with speeds that get you anywhere soon (as opposed to going from earth to a comet in 10 years) - throw out *lots* of energy once. I recall seeing calculations that if such a ship was moving between planets in Alpha Centauri, then we'd be able to track it with our current technology from Earth. So no encounters can be really unplanned - a ship would know *all* the ships in the neighbourhood, and observe all their maneuvers long before they have any effect - i.e., if someone is changing their speed to meet with you, then you know that they have done that long before they actually meet with you. Before you launch, you'd have a database listing where exactly every ship currently is moving, even if they were launched decades ago. Furthermore, everyone else knows if any meetings occur, and where they go afterwards - if a ship gets intercepted, then everyone in multiple star systems know that and also know where both ships go afterwards. [Answer] **TL;NR: Shipping lanes are needed if your ship can't reach traveling speed on its own.** As seen in many books, movies, TV shows and video games, shipping lanes especially make sense if your ship is not able to accelerate to the speed it needs to travel. ## Some examples of "shipping lanes" in Science fiction that uses external Technology: The Game *Freelancer* once established a big network of trading routes you need, to get fast around the planets of the systems. ![Picture of a Spaceship inside a Trading route](https://i.stack.imgur.com/f4MrY.jpg) In the Movie and TV Series *Cowboy Bebop*, they have also established a trading route network (similar to the Freelancer universe). There it is not possible to exit the lane at any point other than the start or the end of the lane. Also there are some side effects from the speed such as "ghost holograms" when you don´t exit the Route right way. ![Picture of the Trading route in Cowboy Bebop](https://i.stack.imgur.com/rRIXF.jpg) So if you have not developed a fast ship or good engines, you need a external force to shoot you in the direction of your choice. --- This makes at least one vector fix if you look at a coordinate system. At the ecliptic plane it makes sense to establish routes to points of interests in a solar system. So the routes you build are mainly fixed in the horizontal but not in the vertical because of the movement of planets and objects you want to connect. A real travel lane could so be a complete plane in the solar system, the next lane would be layer further up or down. Little illustration: ![multi-lane parallel jump-gate junction](https://i.stack.imgur.com/FsuT3.png) Of course the routes would be selected in different angles for every destination, but when you count the time the ship needs to travel, you will need to shoot in a direction where at that moment there is no planet or point of interest. Also the only points where one is likely to come across another ship are still the ports where the ships go in and out of the route. Maybe when the lane is highly populated you have some ships a few hours before you and behind you but an encounter at this scale of things would be lucky. If the points of interest are fixed places in a system you of course would have also fixed lanes form one point to another. [Answer] Under the right set of circumstances, shipping "lanes" in interplanetary space might develop. Other than those specific circumstances, each trajectory will be fairly unique and stuff won't ever share trajectories unless one of the parties wants a close encounter. ## Interplanetary Transportation Network So what are the special circumstances? Consider a very massive payload (say moving an entire asteroid). Reducing the energy it takes to move this object by even a little reduces the over all energy requirements by a tremendous amount. The trajectory that requires the lowest amount of energy involves the use of the [Interplanetary Transportation Network](https://en.wikipedia.org/wiki/Interplanetary_Transport_Network). [![ITN - Interplanetary Transportation Network](https://i.stack.imgur.com/T2IZT.jpg)](https://i.stack.imgur.com/T2IZT.jpg) To use the ITN you must first "pay" the [Hohmann Orbit Transfer](https://en.wikipedia.org/wiki/Lagrangian_point) cost to the nearest Lagrange point (Typically L1 or L2) and then a minimum amount of additional energy to tweak the trajectory as it passes through a succession of subsequent Lagrange points. Travel by this means will take a LLOOONNNGG time, so it won't be used by people or time sensitive goods. For moving large masses of goods this will be the preferred method of transport. ## Lagrange Points There are only a limited number of Lagrange points available (5 points for each significantly massed body). The most valuable of these Lagrange points will be those near the source, target, and the two gas giants (Jupiter and Saturn). The Lagrange points around Uranus & Neptune might be used if you plan to move bodies in their vicinity. Because of their limited number you might even see "congestion" at these locations for a thriving interplanetary civilization that's busy rearranging the solar system's minor bodies. The shipping "lanes" will be those trajectories that link up the most widely used Lagrange points. ## The Trojans and "Space Cities" On the surface of the Earth, people tend to congregate at major transportation hubs. For instance major cities have arisen around good sea ports or the confluence of major rivers. If your interplanetary civilization is busy moving minor bodies around, then at least some of them will pass though the [Trojan Points / Asteroids](https://en.wikipedia.org/wiki/Trojan_%28astronomy%29). The Trojans occupy Jupiter's L4 & L5 Lagrange points. [![Trojan Asteroids](https://i.stack.imgur.com/RuiEo.png)](https://i.stack.imgur.com/RuiEo.png) This means you could plausibly develop "space cities" in the Trojan Asteroids and use them as a base of operations and resupply for the people rearranging the solar system. [Answer] While space is vast and infinite, mankind isn't. Travel 'lanes' through space may include known protected areas that are safe to travel in and free of navigational hazards. Established lanes and routes may have incentives, such as a relay system that allows messages to go to either end of the route if assistance is required. Established routes may have toll fees or required travel checkpoints. An organized fleet system may require that all travel routes be registered in advance for planning and security purposes. What do you have to hide by traveling away from the route, citizen? Traveling outside the lanes could have factors such as a need to avoid authority, ability to get to the destination faster by avoiding the lane, knowledge that the established route is unsafe or being forced to divert due to a hazard on the route. These are the people who are going to have random encounters in space. Ships are very likely more than capable of traveling outside established routes, but it's akin to seeing an old pickup truck speeding off-road across the dusty plains and scrub brush instead of a simple commuter car traveling along the freeway. [Answer] # The right constraint Shipping lanes are not a result of a constraint of choice, but a constraint of resource. I could start a shipping company that takes a scenic route from A to B, but it will go bust because simple competition requires that I take the most efficient route I can, or someone else will undercut me. # Getting about cheaply For the same reason, the most efficient route will be the most popular, and thus effectively a 'shipping lane'; gravitational effects give us the [Interplanetary Transport Network [Wikipedia]](http://en.wikipedia.org/wiki/Interplanetary_Transport_Network), essentially a cheap way to get around the solar system. In space, using these networks can slash your fuel costs because of the [Tyranny Of The Rocket Equation [NASA]](http://www.nasa.gov/mission_pages/station/expeditions/expedition30/tryanny.html). # Planets move ...and so the Interplanetary Transport Network is not a fixed map; it is continually shifting, and occasionally a new route or a sudden change in the optimal route will happen. Stars move much more slowly, so largely interstellar routes should be less likely to move. However, stars are also not much help for gravitational slingshots (precisely because they don't move very fast) so interstellar routes are pretty much straight lines anyway. [Answer] Whether shipping lanes will appear depends almost 100% on whether it is profitable to shipping companies to use shipping lanes. Shipping companies, due to their slim margins, are *very* dependent on profitability of their practice. * If the technology has limited topology (such as gate networks), shipping lanes will be natural. * If the cost of traveling extra distance is low, then it is more likely you will see shipping lanes to simplify navigation (it simply doesn't cost all that much per benefit). * If the benefit of shipping lanes is very high, such as if the need to do rescues occurs often, or the cargo is too valuable to be "lost in space." * If the odds of being raided are high, shipping lanes are more likely (flocking like herd animals). * If the ruling society wants to keep tabs on shipping for tax reasons, they may mandate shipping lanes (possibly by installing checkpoints, which would act a lot like gates, except enforced by society rather than the physics of travel). * Shipping lanes are more likely to form in the mid-range of timescales. On the low timescales, adventurers would dominate, and they do whatever they please. On large timescales, the number of shipping lanes could get so large that they look more like a fluid than a network. In the middle ground, you would see more stranded shapes that look like shipping lanes. [Answer] In short, you can define lanes on stellar maps, for the primary reason that there will always be an "easiest" way to get from A to B, which will be followed by every ship that is trying to go from A to B. However, it will probably be impractical to mark them with beacons or the like as we mark shipping channels with bouys. The difference, in space travel, is that A and B are rarely situated in the same points in space at any two points in time. For interplanetary transit, the most efficient yet direct path is a "Hohman Transfer Orbit", basically transitioning from planetary to solar orbit along a path and at a velocity that will cause you to move between planetary orbits and be "caught" by the planet you're heading to. Even then, that orbital path depends 100% on the time you depart one planet for the other, and therefore the relative position and travel of the planets, determining the point at which you depart one and arrive at the other. In interstellar sublight travel, it's pretty much the same; the stars are rotating around the galaxy at terrific speed, but that means so are we, so we can head nearly directly toward the other star, maybe a fraction of a degree inside to make sure we're not chasing it around the galactic hub (and to make sure we can enter into orbit around the star and not plunge right into it when we get there). These paths will be a little more static relative to the galaxy itself, and therefore ships will have to be vigilant to check for people coming the other way, but "Big Space Theory" will dominate; similar to Big Sky Theory in air travel, space will never be as densely populated with transportation traffic as the roads on the ground, so all in all the odds of a mid-air collision in "uncontrolled" regions of interplanetary or interstellar space will be fairly low. [Answer] According to [this answer to another question](https://worldbuilding.stackexchange.com/a/561/98) an Alcubierre drive would need to have a channel setup far in advance. So with such a technology, you'd need to have a network on established lanes just to be able to go faster than light. Outside the lanes you would not be able to go FTL at all, which for far-away destinations means that you could not reach the destination in your lifetime. Even if this should turn out to be false in our universe (well, we don't even know yet if the Alcubierre drive actually can work in our universe at all!), you still can claim it as requirement in your invented universe. Similar considerations are true when using wormholes for travel: The wormholes naturally would be such points where you would encounter many other ships. When travelling normally in interstellar space, you'd likely want to reach your destination in a straight line, in order to not waste fuel for course corrections. This again would mean preferred routed, which just would be the straight line between both points. This is also true for moving targets, since this would just mean the lane also moves over time. Things get more complex in the solar system (or other stellar systems) because of the gravity. Here a single lane would be less likely; however for ships with similar engines, the optimal energy path at any given time would also be the same, and it could be calculated long in advance, so e.g. pirates would know exactly where to go. [Answer] In a hard science milieu, there is only one real consideration among spacecraft in contention with each other: orbital superiority. Spacecraft within a star system that are available to contend with each other will be in one of only two states: * In orbit around a point of interest. * In a transfer orbit that takes them from one point of interest to another. Points of interest are generally planets, planetoids, moons, asteroids, comets, Lagrange points (maybe a space station at a Lagrange point), or wormholes if your settings allows them. Importantly, these points will always be in an orbit of their own around something larger (planet, main star(s).) Also, transfer orbits can be composed of multiple different stages (think of a deep space probe sling-shotting around the sun). As a side note, transfer orbits (as their name indicates) are themselves orbits around points of interest. What makes them *transfer* orbits is that the orbit is temporarily around a point of interest that is neither the starting point nor the destination. So, essentially all spacecraft are in orbit at all times. Now, like in the movie "Gravity", if your orbit intersects with another craft's orbit at the correct time, you will meet... generally in an event that lies on the spectrum between *collision* and *rendezvous*. Based on the fact that orbits must be planned ahead, often over long periods of time (think weeks and months), the opportunity for two craft to meet in a particular orbit depends on how navigational communication is done in this setting. Is there a system "flight control" that manages all craft? Do you file your "flight plan" with control ahead of time? Is it an uncontrolled system where you happen to have many crafts attempting the same transfer around the same time? Meetings could happen, and perhaps even unplanned meetings. The only remaining problem is the such meetings will almost invariable happen at enormous speed differences. Does this provide the opportunities you seek? [Answer] I think due to sheer size, you can't have lanes unless you have bottlenecks. In worlds similar to the ones found in the Vorkosigan series, you have "shipping lanes" because you travel using wormholes between star-systems. You will see trading posts and major "cross-roads" around those wormholes. [Answer] I understand that the answer is already accepted but: albucierre drive lanes. Albucierre drives create a kind of fold in space you can ride and achieve FTL without really going FTL. A disadvantage (besides needing more negative mass than there is observable positive mass in the universe) is that you lose the negative mass while traveling. The solution: send a slower-than-light ship that creates a lane of negative mass, allowing ships afterwards to have an easy time traveling along the lane. The creation of such a lane takes years of travel time and the generation of the negative mass (assuming its possible) is probably going to take some time too. So a star lane is going to be pretty important, but if you really need to you can use more expensive travel off-lane... Unless you chose to make that so expensive its not an option. [Answer] This depends on what level of travel the "shipping lanes" are at, if it's at an interstellar level, then possibly depending on the type of FTL travel; any type of stargate or wormhole style, such as in [Babylon 5](https://en.wikipedia.org/wiki/Babylon_5#Setting), or the [Human Reach](http://www.thehumanreach.net/setting_home.shtm) series works well for this. However on an interplanetary level, there really is no such thing, as spacecraft will, again depending of the drive, have to plot a new route each journey, as their destination is continuous moving and they themselves are moving around various celestial bodies. Of course if you take into account things like [Hohmann Transfer Orbits](https://en.wikipedia.org/wiki/Hohmann_transfer_orbit) and ships trajectories, this means while you do not have shipping lanes you have predictable routes that a ship will travel; some paths are more fuel efficient then others A good site for further reading on this topic would be the [Atomic Rockets](http://www.projectrho.com/public_html/rocket/) website created by Winchell Chung [Answer] # Short Answer: Yes *During one of my college electronics classes, an industry engineer was presenting about FPGAs (Field Programmable Gate Arrays). At the end of the presentation, a student asked why the engineer went to such great lengths to optimize the gate array design? His answer, "If we don't, our competitors will."* Shipping lanes will always exist. There will always be reasons to avoid or circumvent them (like piracy...), but they will always exist. There will always be the fastest routes (given enough expense) and the most economical routes (given enough time) and which will be used will depend on the tried-and-true realities of supply and demand. The primary difference between shipping routes in space (regardless of the mode of transportation) and those on Earth is that Earth's routes are only 3-dimensional (two spatial coordinates and time), in space there are four dimensions (three spatial coordinates and time). However, while that complicates the derivation of space lanes, it doesn't change the realities of economics: cost and time. Yes, space is big. So unless a LOT of trade is occurring, the odds of actually encountering another ship are pretty low. "Outbound" lanes and "inbound" lanes will almost never cross, but the same most-efficient-transfer-orbits or fastest-transfer-orbits will always be used. In the end, the lanes will exist because one's competitors will always seek the path of greatest profit. [Answer] I would like to add some things. First, the asteroid belt is one of the least accurately depicted things in sci-fi. Star Wars, Star Trek and many other more or less popular stories show an asteroid belt as a region of space dense with large rocks frequently colliding with each other. There is an excellent answer about the density, or actually the sparsity, of our Solar System's Main Asteroid Belt: <https://space.stackexchange.com/a/1388/47491>. While some other star systems might have densely packed asteroid belt, I believe our Main Asteroid Belt is an example of a typical asteroid belt. I have seen only two sci-fi stories somewhat accurately depicting an asteroid belt. First is *2001: Space Odyssey*, where one very distant asteroid crosses the screen in one of the scenes of the two-hour movie. The second is *The Expanse*. In the books where the story is set around the Main Asteroid Belt, Jupiter and Saturn, the action takes place at particular asteroids and space stations: Ceres, Eros, the asteroid at which the *Canterbury* gets ambushed and destroyed, asteroid on which the *Rocinante* crew finds a stealth ship hidden by Julie Mao, Tycho Station, Toth Station... In reality, when travelling in space, the only indication you are in the asteroid belt would be your ship's radar detecting asteroids and navigational computer comparing them with previously established maps. Second thing, *The Expanse* also shows how space pirates would operate: lay in ambush relatively close to their prey's predictable route, hiding behind an asteroid or so close to one that radar have difficulty in distinguishing ship and asteroid, with the drive off, transponder off, active sensors off and only passive sensors on, and reducing heat radiated out into space, and some kind of bait in a trap. And when the prey is in the trap, then take action. **Third thing**. Something else you have to consider, in addition to what's described in other answers, **is the intensity of space traffic.** How many people are in your Universe, and how are they distributed? Are humans (currently) the only spacefaring civilisation? If so, are they only living on Earth and occasionally sending some scientific probe out into space? Are they mining asteroids? Do they have permanent settlements on Mars? Are they living on every planet, moon and significantly large asteroid in our Solar System? Do they inhabit nearby stars? Galaxy(-ies)? Or are there other spacefaring civilisations as well? Are there less advanced civilisations too? Has it led to colonialism? Do colonised societies fight for freedom? (Which would be cause for moving military around.) How many people are travelling in space or working in shipping commodities around? What cargo is transported from where to where? What are distances and speeds? What cargo would pirates be interested in, in terms of value, probability of getting caught by a law enforcement agency, and how easy would it be to sell it on the black market? Is traffic organised? How? For what reasons? Who is doing it? Is there a traffic control authority you have to submit your flight plan before your travel? Are they following whether or not you actually fly the route you submitted your flight plan for? How? AI-controlled observatories tracking spaceships in real time and comparing with submitted flight plans? Maybe regulations force shipbuilders to build in systems for automatic sharing of navigation data with traffic control authorities and other ships in reasonable vicinity? Perhaps on less frequently travelled routes with a high probability of pirate ambush, cargo ships travel in groups escorted by the military? **In conclusion**, considering different aspects and scenarios, it is plausible that shipping lanes of some kind in space would make sense. [Answer] ## Flight paths This is analogous to flight paths in airspace. Aircraft follow defined flight paths for several reasons. 1. To facilitate air traffic control. 2. To avoid collisions. A light speed collision would be messy and impossible to avoid. 3. To follow the shortest distance between two points. 4. To allow refueling stops. The more crowded space gets the more important shipping lanes would become. I would imagine the space around major planets would be tightly regulated. The space between stars would need to be monitored to avoid collisions. [Answer] Shipping lanes make sense in most scenarios. Take the example of ocean travel, for instance. A sea is (mostly) very empty, and a ship that's taking one particular route may just as well take another. But even then, shipping routes exist. This is due to a variety of reasons: Efficiency: Most ships prefer to take the route that will be the most economical, to conserve fuel and labour costs. The most efficient routes thus become established lanes. Security: A well-travelled lane is less likely to be raided or blockaded, as an efficient route is a resource most nations guard jealously: it is why large navies exist with the very purpose of safeguarding trade routes. Thus, vessels will naturally want to take thos routes. Safety: The sea is fraught with dangers like rocks, storms and maelstroms. A trade route is mostly established in such a way that it passes through areas where these dangers do not or are unlikely to occur. Thus, ships will want to use these routes, as there is a guarantee of no unexpected surprises. These same reasons can be applied to space as well. With the ever-present dangers of ion clouds, asteroid fields, solar storms, pirates and raiders, it is natural for traders to stick to relatively clear routes. Once these become recognized trade routes, governments will probably employ resources for their protection, because trade is an integral part of the economy. Indeed, companies might spring up whose very purpose is to manage and safeguard these routes, charging heavy duties in exchange. But if there is need for secrecy and speed, there will always be a black market for unregulated couriers and merchants, who, instead of sticking to safer, but time-consuming routes, carry their wares through open space. Dangerous, but also very much paying... [Answer] We *already have* space shipping lanes. For example, after more than two years with no Mars probes being launched, the [UAE’s Mars orbiter](https://en.wikipedia.org/wiki/Emirates_Mars_Mission) launched on 19 July 2020, [China’s Tianwen-1 lander](https://en.wikipedia.org/wiki/Tianwen-1) launched on 23 July 2020 and the USA’s [Perseverance lander](https://en.wikipedia.org/wiki/Perseverance_(rover)) and [Ingenuity helicopter](https://en.wikipedia.org/wiki/Mars_Helicopter_Ingenuity) launched on 30 July 2020. That wasn’t a coincidence, it was because the relative orbital positions for [the most fuel-efficient journey from Earth to Mars](https://en.wikipedia.org/wiki/Heliocentric_orbit#Trans-Mars_injection) only come up once every two years or so. [Answer] Maybe. It would depend on which era you would place the "shipping lanes" in space in, and also on the speed on how the spaceships would travel. As you said, space is big. If the spaceship traveled faster then light, and DEFINITELY faster then a peregrine falcon, then maybe it would work. ]
[Question] [ **Closed**. This question is [opinion-based](/help/closed-questions). It is not currently accepting answers. --- **Want to improve this question?** Update the question so it can be answered with facts and citations by [editing this post](/posts/120828/edit). Closed 5 years ago. [Improve this question](/posts/120828/edit) Yup. All my pigeons are now spoons. I knew my court alchemist was a sore loser, but I still think it's inappropriate to do that for a chess game. He vanished and I no longer have any means to communicate. Horses can also send messages, and are useful for long ones, but I still want a way to send short messages quickly. How could I send short/quick messages without my pigeons? P.S.: I now have plenty of spoons, so bonus points if you use them to send messages. Update: on the message note he left, this bloody alchemist said that **all** pigeons of my kingdom are spoons, not only my castle. My kingdom is quite large (something between your England and France), so I need a long term solution. The sooner the better, but at least my horses aren't forks so I can wait something like one month, but no more. Messages I sent with pigeons were *Short Message Swearing*, AKA *SMS*, to send short classical orders ("besiege this castle", "gather your army there", "betray my brother"...), usually when it would take more than a day with a horse. [Answer] *Inspired by Hosch250's comment* 1- Carrier pigeons don't actually go to a any given location, they really just return to their nest. 2- Spoons have an annoying tendency to fall into soup bowls. Take advantage of these two facts. Your pigeons are spoons on the outside but they're still pigeons on the inside, only very confused. Get another alchemist (surely you don't only have one) and have them transmute pigeon nests into soup bowls. Their instinct will catch up to their new body and they'll develop a strong desire to fall into their own bowl. Then dispatch messages by horse explaining what you did and ask for the bowls to be filled with soup. Your carrier-spoons will now gladly "fall" back in their bowl. People might need some time getting used to this though... [Answer] Polish them to a mirror shine. Put one spoon with one operator on a tower within visible distance from another one. Invent coding that uses "long shines"-"short ones". Important messages would still be sent by horse (because it's harder to stop a messenger on a fast horse) and frivolities can be sexted with Morse code. **EDIT** The use of a horse is to secure delivery of important message. First you avoid the message to be stuck down on the road due to "some" conditions. Second - you avoid many people learning about the message (the Shiners should know the code, not just repeat shines to avoid a game of Telephone where messages mutate over time). Third - using towers means your messages go through well known route. Messenger can go off the beaten track or disguise himself to protect the information. [Answer] Get another alchemist, convince him to use Sympathetic Magic to bind pairs of spoons together so that what happens to one happens to the other. They're already identical and infused with magic from the transmutation, so this should be technically easy to accomplish. Now construct a pair of Ouija style code-boards covered in words and letters and place the bound spoons on them. When you move one spoon, the one on the other board will move to match. So you can use this to send instantaneous messages at any distance. Send one of the paired board/spoons to another castle and assign someone to keep a close eye on the board at each end for messages. Repeat the process and you'll have a network of instantaneous text-communication devices across your whole kingdom. A great improvement over the carrier pigeons! [Answer] Crows. If you don't have pigeons anymore, your other simple option is to use crows. They are very intelligent, great memory, longer life span, stronger etc ... Some would argue to use ravens because they are stronger, but they are less sociable and less comfortable around humans. But you can train them anyway. [Answer] Being in the medieval period I assume your mines are mostly producing copper, tin and some low quality iron. What your alchemist did was turn your pigeons into high quality stainless steel, or possibly even sterling silver spoons. Sell you spoons for a hefty profit and buy some more pigeons. Spend the rest of the money finding that alchemist! Edit: collect all the other spoons as property of the crown. You are RICH!!! [Answer] One solution could be [semaphores](https://en.wikipedia.org/wiki/Semaphore_line). This require no special technology, and was used before the telegraph was invented. Chappe's semaphore towers is one historical example, used in France. Just separate towers by 10km each (or use already existing castles, churches...), and write a code. bonus point: You can use some spoons to make semaphore arms more shiny [Answer] Hire another fickle Court Alchemist. Provoke them after mentioning how the work of their predecessor was amazing - he turned all your pigeons into spoons. Finish another victorious chess game with '*I guess that's it! Just like those spoons, it's not like you can turn them back. But, hey, I suppose it's good to admire the work of your betters, right?*' Profit! (I hope.) [Answer] I don't see the problem. Surely, you can find someone to enchant wings into your spoons? And engraved flying spoons are a clear improvement over pigeons. Make sure to keep the fancy golden spoons for important messages or favored minions - standard dinnerware is good enough for your average flunkie. [Answer] [**Pneumatic tubes**](https://en.wikipedia.org/wiki/Pneumatic_tube) It not only allows to send messages, but smaller items without interruption with speeds up to 40-90 km/h. The system is from a mechanical viewpoint absolutely doable in mediaeval times, it is just that nobody had the idea to actually do it. My current hometown Hamburg had [several long pneumatic lines](https://de.wikipedia.org/wiki/Rohrpost_in_Hamburg) to avoid transporting letters with cars. The diameter was 45 cm, the length of a transport pipe was 1.6 m, so approximately 1000 letters could be transported with ease. It was quite a modern system, it was constructed from 1962 on. What needed half an hour with a postal car was now done in few minutes. Unfortunately the vibrations of the roads caused misalignments and damages, so it ran only until 1976. Many of the old systems are still buried under the ground. All in all the lines had a length of approximately 50 km. [![enter image description here](https://i.stack.imgur.com/H3qNA.jpg)](https://i.stack.imgur.com/H3qNA.jpg) *Wikimedia Commons, Public Domain, Prof. Dr. Nemo Klein, 2006-09-20* [Answer] You could use the spoons to make a sort of medieval LRAD. Bind the spoons together to make a very large parabolic satellite dish. Turn the chamber towards the place where you want the sound to focus, stand in front of the parabola, and shout loudly into it. The shape of the parabola will determine the distance between itself and the focal point, which is where the sound will be most audible. So, I suggest that you construct this parabola by attaching each spoon to a geared tuning mechanism for adjusting the parabola. You have your engineer turn a crank which moves hundreds of small spines along fixed paths, with the goal of effectively driving the focal point farther and farther away. Now, if it gets too far away, then even though you shout very loudly, the sound might just not make it there. So, to complete this design, you need to hire a large chorus to loudly sing all your secret messages into the parabola. If the chorus is good and large, and the parabola is shaped precisely, then you should be able to send these messages remarkably far, and they would be most audible at their focal destination. Granted this only works with line of sight, but if you have enough spoons, I see no reason why you can't have acoustic spoon-satellites with large choruses in several locations around the empire. [Answer] Use your horses to go to someone else's kingdom and import pigeons back to your kingdom. *You specified that you have a big kingdom and not that you have the only kingdom in existence ;-)* [Answer] Spoon catapults! Place the spoon over a branch (or similar), put your message around a small stone, place the stone in the scoop, take aim, and whack the handle! You'll have to whack quite hard to get the range of a pidgeon, but that's what sledgehammers are for... [Answer] Two methods I can think of off the top of my head: * Semaphore. Using a pair of flags in various positions, they are best used with relay towers and can send messages for miles. Reusable. * Fire signals. Using the smokes of bonfires and blankets to produce a crude form of morse code. Needs fuel to be used though. [Answer] **Use Kites** Kites can be used to send messages. They are cheap, can be easily flown with little expertise, you don't need to build expensive towers, they even work at night by flying lanterns along the string. The combination of size/shape/pattern/color of the kite can convey the message. A network of kite flyers throughout the country can convey messages over long distances. Rotate the phrase-book every few weeks to stop the enemy from decoding your intentions. Cons: You're out of luck if it's raining or very very still weather (no wind) [Answer] **You will want to play those spoons.** [![playing spoons](https://i.stack.imgur.com/uUJBY.jpg)](https://i.stack.imgur.com/uUJBY.jpg) <https://www.youtube.com/watch?v=GhggIC0D--4> I think of the fantasies in which there are a series of towers on which bonfires were set to be lit in time of need. The next tower along to line would see the fire and light their own, and so the signal propagates. So too with your spoons. The spoon player would sit in front of a large parabolic dish many meters across, and play the message. Atop the next tower the next spoon player listens in front of his own dish pointing to the first tower, which captures and amplifies the distant clicks and clack. He then walks around the tower to the transmitting dish and sends the message on. [Answer] As the ruler of a great kingdom, surely you have multiple options: * Sell all your spoons to a neighbouring kingdom that does still have pigeons to buy them * Commence a nation-wide manhunt for the court alchemist (reward: spoons) and 'convince' him to fix the situation * If there's powerful magic in your world, have your court mages send 'long-range fireblasts' set to explode at given intervals akin to morse code (obviously you'll need a code book so the enemy won't decipher the message) * Start experimenting with turning birds into enormous, mountable monstrosities / combining bird and man into one body * Appoint volunteers who will attempt untested teleportation magic with ancient, recently discovered runes or transmute them into pigeons [Answer] **Drums and communication by sound** With drums you can encode short messages as a unique pattern of sounds and sound travels really fast (>300m/s) and a chain of drummers situated at suitable distances can transmit the message on and on. If you are worried about the drummers making mistakes inventing some form of [error correction code](https://en.wikipedia.org/wiki/Error_correction_code) might be a good idea. Only drawback: That constant drumming in your castle and in all areas around it will drive you crazy. Alternative: Try [Didgeridoos](https://en.wikipedia.org/wiki/Didgeridoo) or [Alphorns](https://en.wikipedia.org/wiki/Alphorn). [Answer] Shine them up and trade them to crows in exchange for delivering your message. [Answer] Create a minor catapault network using only spoons and branches. You can probably launch a short message several dozens of meters per spoon. Assuming you have many hundreds or thousands of spoons now, you should be able to link your communication network up. It's a bit vulnerable to high winds, but then again, your birds kind of were too. [Answer] Melt and/or beat the spoons into **rockets**, with the message in a fireproof nose cone. If your kingdom has strong magic, a little alchemy to create gunpowder or [V2](https://en.wikipedia.org/wiki/V-2_rocket) fuel shouldn't be too advanced. [Answer] In this answer, I assume you have metal spoons. Melt the spoons together end to end and transmit an electrical signal down the long conductor, with earth ground as a reference point. It's relatively crude, subject to interference, and only useful for relatively short distances over preplanned routes. You might need error correction codes or a second line of spoons for a ground. Depending on technology and heat available, you could even melt the spoons down to wires to cover a longer distance. While my initial thought was the mirror/sun reflection answer, this one works at night and on cloudy days and doesn't require adjustment for angle of the sun. ]
[Question] [ I am a Dragon and I have an infestation problem in my world. Currently, I am the single one of my kind and your representation of a dragon in movie Desolation of Smaug is fairly accurate only there's no such thing as 'magic'. All of my life I had enjoyed an indolent lifestyle: hunt when I am hungry, sleep when I am sleepy, and ponder on the meaning of life when I've got nothing else to do. I don't remember when the humans first appeared but they've been around for some time in one form or another (I had tried to keep the count of passing seasons at some point but lost interest after several thousand cycles). However a couple centuries ago I stumbled upon an amalgamation of humans they'd called a "Kingdom". There I found an interesting contraption(some kind of torsion powered spear thrower) that I suppose was designed with a sole purpose of bringing me down from the sky. Needless to stay it utterly failed. In a fit of rage, I burned down all hummies and their dwellings in sight for such insolence. But then I noticed a disturbing pattern: from the earliest memories of these creatures that I have, I remember them still hairy as your average wolf throwing stones at other animals. Then they started throwing sharpened sticks instead and then using some primitive yew devices to launch those. There is a trend: they progress and their ability to kill other beings improves over time. Back then I thought that I can easily solve the issue by exterminating them completely. I had burned every human being in all of the "Kingdom" and then continued doing so through the rest of the continent. I then doubled back and flew to the next continent over the Great Sea where I found more human amalgamations(I still wonder how they've managed to get there - it takes a week of continuous flight for me!) and burned them down too. I took my time exploring the continent(I hadn't been there for a very long time) and noticed that some of the meals that I liked from before were now gone and I knew whom to blame. I checked the other continents and found more humans on every single one of them. I wiped them all out. Then when I was done with my campaigning I returned to check on the "Kingdom" and found a big amalgamation of humans numbering in thousands not very far away(a day or two of flight). I burned them down. I scoured the continent all over again and found more humans... I had spent the next two centuries campaigning all over the world several times over. But every time when I leave a place it gets infested with humans in a matter of decades. They survive in small bunches and then multiply like crazy. At this point, I don't even know if it's worth the effort to keep going like this. Long gone are the days when I basked in the sun leisurely without worrying what region should I cleanse the next moon. I must admit that these creatures seem to be only slightly inferior in terms intelligence. After all, they are the only other creature in this world capable of harnessing fire. I also have to admit that I should've exterminated them when they only inhabited a single continent(or just limit the infestation there). Here is my question: How can I keep these hairless apes at bay and prevent them from inventing new ways to kill(specifically me). Culling seems to do the job, but it is very tedious and time-consuming. Is there a way how to solve the issue permanently or at least optimize the process? [Answer] Ordinarily, you'd delegate. Farm out the mucky business of war to someone else, found one of these kingdoms of your own, get generals to rampage. But an exercise in nation building doesn't seem your style. Too much work, you won't get them all, and eventually someone will figure out how to kill you anyway. Have you considered planning for retirement? You're still young, you can still burn down anything you please. Spend another century or three burning for hire while technology hasn't caught up. Get paid in valuables. Invest in a diverse set of assets - kingdoms, land, merchants, inventors, banks, and so on. Hire capable people to manage your money. Once the burning business starts to dry up announce your retirement from burning and looting. Hopefully by now you've gotten yourself a healthy passive stream of wealth from all your investments. Scrupulously avoid anything that might be construed as *politics.* Then, become the most terrible thing known to these puny humans: a *tourist.* Lounge in exotic locales, have tasty food brought to you, host burning man festivals... whatever you please. "Is that the dragon outside parliament?" "Yes, Prime Minister." "Is that... is that a tiny camera in its claws?" "A Nikon, I believe." "What do you think it wants?" "I think it wants a selfie, Prime Minister." Edit: And if they manage to start world war 3, you can just find someplace out of the way to ride it out. That's *politics* and you don't do politics. At least it's going to be nice and quiet again afterwards. Maybe you can teach the giant cockroaches or whatnot how to make a piña colada. **The Brass Tacks:** Fundamentally this strategy is about managing risk while still aiming for your ultimate goal of achieving a long, enjoyable life of leisure. It assumes you can't really *stop* humans from advancing and decides it's wasteful to spend time delaying them; instead it focuses on leveraging different strengths to exploit the humans in service to your ultimate goals. **Phase 1: Burn** In the initial phases of your plan you're invincible- you don't have to worry about your threat profile. Burn as much as you want. Your objective in this phase is to convince humans to pay you to burn their rivals instead of them. Don't worry too much about with what, you'll get a handle on what tends to stay valuable across civilisations, like gold. Try to do this in as many different places as you can. **Phase 2: Invest** In this phase you've gotten yourself some wealth. Some of it will turn out worthless; that's fine, it's why you diversified. Remember this principle, it's important. Keep taking jobs to burn, but now your objective is to start investing. Start small, find needy humans and offer them loans. For example, you loan out enough to get a farm started, in five years time you'll be back for that and 25% interest. Lean towards generous - every farmer, merchant, king, and craftsman who says 'the dragon helped me get on my feet' chips away at the myths, and letting them repay on fair terms leaves them satisfied you're a good business partner (important, since you're immortal). Optimally, start phasing out the burning once it's less profitable than loaning (including losses to war, betrayal, etc.) **Phase 3: Tourism** This phase starts around when the humans start getting weapons that might actually hurt. In human terms, you're looking at around the fifth or sixth century (Beowulf happens around here). Phase out burning completely, it's a liability now. Start pivoting away from politics, too. Time to put your appetite to work. Your objective is to acclimatise the humans to your presence. Tour the outlying parts of human lands, where they can't afford to fortify against you, and hang around. Buy things from the locals, pay them to feed you, and if the army shows up (whether or not they can actually hurt you) or you're asked to leave, just take your leave and fly away. Here you train the humans to think of you as a big positive to have as a guest, and wasteful to drive away. It costs a lot to raise an army and maintain dragonslaying weapons - by making them waste resources overreacting (and costing them the opportunity to sell things to you!) they'll gradually scale back their defences against you or get naturally tromped by those who do. **Phase 4: Dragon of Leisure** This last phase starts when you've gotten the humans comfortable enough with your presence to fly into their capital and scratch them behind the ears (humans like that, right?) The key time for this is before ~1900 when they develop flight. From here your physical advantage is gone, because now the humans' defenses against each other will work just as well as against you. You need to reach this stage before then, and leverage your money and carefully built reputation instead. Start delegating away direct control of your affairs to humans. Acquire a trustworthy staff (you've got millennia of experience with humans by now after all) and have them handle the day to day affairs of your life. Only handle the important decisions yourself. From here you can do whatever you please, busy yourself enjoying life. Sleep when you're sleepy, eat when you're hungry, get introspective when you're bored. Best of all now you're such a good customer and you've got all that money humans like, they're going to go out of their way to make even nicer places to sleep and tastier things to eat and invite you to take selfies. [Answer] There is a possible way for a dragon to succeed for a while, but it depends on his communication skills. Humans would have to kill other humans. On every continent, the dragon would need to come in contact with nomadic tribes and make these tribes worship him. He would request massive gifts and sacrifices from his followers. In the process of serving the dragon, followers would need to attack and raze any permanent settlement and kill or enslave its inhabitants. Only nomads are allowed to live. If a tribe is not doing a good job exterminating "kingdoms", dragon can either help the tribe, or turn on it, selecting a different tribe for the same job. It would still be dragon's big task to inspect all the corners of the world and reinforce loyalty among his followers. [Answer] Your pest problem seems unusual. Not only do these hairy apes reproduce about as bad as rabbits, they seem to have an intelligence of sorts. If this is true, your days are numbered. They will eventually out number your death dealing capabilities in addition to having the ability to kill you. I recommend that you form a beneficial relationship with them before it is too late. As with all relationships, communication is key. What do they need? What are their desires? What can you provide them that they can't provide for themselves? Since they now appear everywhere, they probably like to travel. Are you willing to take them to various contents for a small fee which includes fresh water, your favorite foods, and safe lodging? I'm sure the ones that have arrived at new locations desire stuff from the old location. It could be rocks of a certain type, dried vegetation, or something as odd as the stuff that comes out of caterpillar's butts. - gold, gems, spices, silk Your ability to fly across continents in weeks should provide them with a benefit for not killing you. You need to figure out how your fire breathing can provide a benefit. Do they need fields cleared? Fight a wildfire? Melt rocks? However, whatever you do, you need to make sure that the relationship does not become abusive. Your friend, Dear Abby [Answer] # Go all Roman on them and salt the earth (sort of). In the world I come from, there are no dragons, and so humans have instead turned their energies towards coming up with nasty ways to kill and torture each other. Some of these creative energies were channeled in what we now call the [Third Punic War](https://en.wikipedia.org/wiki/Third_Punic_War), where a place called [Carthage](https://en.wikipedia.org/wiki/Ancient_Carthage) was pretty much totally destroyed by the Romans. Stories tell that [the ground was sowed with salt](https://en.wikipedia.org/wiki/Salting_the_earth), essentially in an attempt to make it uninhabitable. Those stories are likely false, but then again, the Romans survived to tell them - not the Carthaginians. Even if salting the earth actually happened, it probably wouldn't work very well, and at any rate, you probably don't have the massive amounts of salt needed to cover large areas of the planet. However, you're a large, flying beast with fire and apparently a lot of time on your hands. Your problem seems to be that you're not being sufficiently devastating when you destroy entire human settlements. They can come back and start anew. Therefore, you can go about destroying the means of sustenance in an area, in some interesting ways. * If humans like an area because it has plenty of wood to make buildings and spears and other things, **burn down the forest**. * If animals are plentiful enough in an area so that humans can eat them, disrupt the ecosystem by **scaring away the animals**. Kill as many as you can, and frighten the living daylights out of the rest. * If there's arable land for growing crops, **burn the crops down** when they try to plant any. Or encourage local animals to eat the crops. * If there's a river nearby that's good for transportation, **block the river** (note: this works better for small rivers). Stones, trees, and other large objects can make travel inconvenient. You're strong enough to move these things. * If there's a lake that provides fish and water, destroy any dams (natural or artificial) and try to drain the lake. * **Burn everything.** To be honest, half of these suggestions boil down to that. Just light plants on fire. Humans don't want to get on the wrong side of a [wildfire](https://en.wikipedia.org/wiki/Wildfire), and they probably don't have means of stopping it. ### Notes: * These work on small scales, not continent-wide ones. Come on, you'll never rid the world of *all* the humans. But you can keep several small domains in check. * Side effects may include the total destruction of all ecosystems in your area. Sorry. [Answer] On one hand, you can't burn them all, on the other hand, collaboration is a risky path - eventually, someone will betray you. **You need a third way: Become God.** Find a relatively large and strong tribe, preferably one that you did not burn recently. Strat helping them from time to time, convince them that you are the one and only god, creator of the world and humankind. It shouldn't be particularly complicated - you are obviously different, stronger and smarter then they are. With your help, this tribe will conquer many others, and their religion (i.e. you as a god) will spread even further. They will even give you food and other gifts. Eventually, they won't need your assistance, but your godly nature will likely remain unchallenged for centuries - you are a living proof that God exists. Moreover, the believers are quite unlikely to betray you, and will even *defend you* at any cost. Hopefully, if a time comes and unbelievers form a majority, the ethics will change and you will become a national symbol\heritage, or at least an equal member of society. [Answer] The problem with your current approach is that the smartest/fastest/strongest humans are the ones who figure out a way to escape your cullings, which means that over the next several thousand years your problems are going to get worse and worse. The answer is to domesticate them. Sure, it's more work at the outset, but it pays dividends in the long run. Take some time to observe and analyse the humans in every area. Figure out who the stupidest, slowest, weakest ones are. Deliberately spare them. Do your utmost to wipe out everyone else as thoroughly as possible. Now you've created a selection pressure for stupidity and weakness. You may need to help them survive so that the natural hazards of their environment don't wipe them out. It will take probably a thousand years of constant attention, but you should be able to get to the point where the average human is no smarter than the average cow, and considerably less capable of fending for itself. Anyone who builds a structure more complex than a mud hut gets burnt. Anyone who uses metal gets burnt. Anyone who stores more than two month's worth of food gets burnt. Eventually they will come to see doing these things as inherently bad, and then you tighten the screws, but always keep rewarding and protecting the ones that are the most animal-like and least intelligent. Eventually when none of the remaining ones can survive without your help, simply retire to your cave and let nature take its course. [Answer] In the world from which I hail, I have discovered that, every once in a while, a small plague will pop up in some corner of the world. Devastating to the humans, but my physiology is different enough from theirs that they never seem to affect me. Now, these silly humans have yet to figure out how these plagues spread - sometimes rats, or fleas, or contaminated blankets, or leftover corpses - but I find that I can usually figure out how it spreads with a few short months of observation. The thing about humans is that, despite their near-draconian level of selfishness, they are still herd animals at heart; and as such, they are total suckers for someone who claims to have their best interests at heart. So I have made a little game of waiting on the fringes of a plague outbreak until I figure out this plague's vector, then waiting until the leaders who have heard of my charitable ventures in the past come petition me for my aid. I then perform a cursory, highly visible inspection, at the end of which I tell them stories of how the last plague was spread by rats, and I'm terribly sorry but I must go on a burninating rampage against rats but never fear I can provide transport to a limited number of refugees, but because the number of people I can transport is so small, you should make sure the people I take are the most important, morally upstanding, and most likely to blame the inevitable plague following them on the evil humors of the people who help them so selflessly at their destination (bonus points if you can arrange it so that only the natives of the new location get sick, and not the refugees). This works so well, and the finger pointing is so effective, that they never seem to pay attention to the blankets I insist they be bundled up in for the journey (or whatever the actual vector is). Frequently the humans burn their own necessities of life on their own without my intervention except when the plague seems in danger of dying out. One of the most fun things to do with this model is to announce that you were wrong about what the cause of the plague is. The humans actually invite you to do another round of burninating everything! And through it all they revere you as their savior! Eventually, though, someone's going to find the true vector. I have a few different responses when that happens. If the plague is going well and the discovery is out of the way, I might cleanse the area that discovered it. But eventually it will run its course enough that I can publicly abase myself for making such a mistake (humans are suckers for false humility in an obvious superior), but if we burninate the right things now, we can finally nip this plague in the bud and save the rest of the populace. Play your cards right, and they will only remember how nobly you rescued them when the truth was finally discovered, and forget the burninating that was "accidentally" done against the wrong targets. Side note: I once had a group of knights discover one of my stashes of objects contaminated with previous plagues. They actually believed my excuses for the noble reasons I was keeping them around (I think I said something about containing the evil or something like that), but that ended up being a moot point, as they didn't survive long enough to tell anyone anyway. [Answer] Your goal is to exterminate or at least control the spread of this awful infestation, so let's laugh together at the various suggestions of cooperation and then eat those who proposed such obvious nonsense. What you want to do is attack the **weak spots** of these creatures. Two of them are useful for your needs: One, they like to kill things. Encourage them. Especially killing each other. That's very easy - while human-sympathizers might try to talk you into religion and politics, that's all just so much nonsense. Humans fight over two very simple things: Resources and mates. I'll talk about resources in a second, let me talk about mates first. The reason these creatures multiply like rabbits is that there are men and women. Simply put, if you put two of them together, they multiply. They also enjoy the process a lot, so each man tries to get at least one woman and vice versa. Figure out how to spot the two genders, there are some obvious physical differences. Then figure out which of the two genders is dominant in the tribes in your area. Then check if their daily habbits are different, e.g. one gender goes hunting all day and the other stays in the camp or whatever. Eliminate at least half of the non-dominant gender and watch the now more numerous dominant gender fighting over what is left of potential mates. I can assure you this works brilliantly and all the religion and politics these monkeys invented are basically just elaborate ways to solve the mate-distribution problem. By introducing a considerable artifical scarcity, you break down their social rules, and they will proceed to kill each other over mates. For variety, kill all of the non-dominant gender and watch the remaining humans raid neighbouring tribes for mates. The second attack point is resources. Food is the obvious one, if you can spot others, just add them. Humans can hunt, gather or farm, but only farming provides enough food to allow for large settlements, and only large settlements allow for division of labor to the point where technological progress is possible that can endanger you. So your goal is to prevent large settlements from forming, and that you can easily do by torching every field and farm you come across. No more hunting for humans hiding in caves and forests. Just torch their farms, watch them starve and return to hunting and gathering. Divided, reducing their own numbers through warfare and raids, and unable to form large settlements without farming, they will not be a threat for a long time. Now there is one thing about the farming that you need to figure out by yourself: When burning a field, you can actually make it more fertile. You want to avoid that. Find out by trial and error at which point in time or with what crops planted you need to burn to **reduce** fertility instead. [Answer] I do think that Alexander's answer is the best solution for it, But its not good to kill those who serve you, for sometime, kill them later at least! The Dragon **SHOULD** ally with some Kingdoms as well, and **PAY** them, either with gold, land or protection. That way the kingdom will serve the dragon blindly, destroying any kingdom the dragon orders to be killed BUT do take note that this will cause problems for the Dragon because yeah, he does keep some humans along with him, which in turn, may kill him also when he least expects it, so what to do? The dragon should still ally with some kingdoms, and give them presents, he must mark a kingdom as an ally, an enemy, and the neutral. The **Ally** Kingdoms are the ones who will do the killing, they will burn down other kingdoms for gold, land and protection. This kingdom's size should be sizable enough for the dragon to destroy in mere seconds, so when the dragon has "fatten this pig", its this kingdom turn to die. The **Enemy** Kingdoms must be the biggest kingdoms there is, because if the dragon chooses an ally kingdom that is already big, it might take a very long time for the dragon to destroy this Kingdom, AND this kingdom may take it on their own to kill the dragon. With the support the dragon gives to his allies (gold, land AND protection), this kingdom will fall. The **Neutral** Kingdom, will be his reserves, they may at first, would not adhere to the dragons' orders to be his ally, or maybe reluctant. They dragon must leave them be, and comeback once his fatten pig is dead, then demonstrate a little of his generosity to them, and if that fails, he could also burn them to the ground. The point of this tagging would be it would create a stable cycle of death where more humans die than those who are getting born, choosing lesser kingdoms to deal with the big ones will makes the dragons task easier, as his next meal will be that ally of his. [Answer] Sorry to hear that, mate! Sounds like you're really in a troublesome situation and no mistake! We certainly commiserate with you: we have similar troubles in our world, too! Thankfully, Dragons back in the long ago Dream Time were wise enough to realise how much of a threat the Apes kindreds were like to become. No one really took much notice of them at first, and by that time, they were pretty wide spread in the Southlands. But as others here have said, once they start making food grow from the earth, you'd better deal with them right quick or else all Dragons will be in danger! If there's one thing the Ape folks can not stand, it's *competition* from another intelligent race! At first, we did just as you are most bravely doing now: scour the world and burn the lot of em wherever we found em! But like water breaching a dam, the Apefolk just kept filling in the gaps left behind. That's when the Seven Queens of old determined to do something more constructive about the problem. Sure, some of The Wise counseled cooperation and coexistence or even outright political control of the Ape kingdoms. Pssshh! But, really! How boring would that be having to constantly be on the watch over their stupid antics! No, it was decided at the last that all Dragon queendoms must be urged to send out warriors to scour the entire landrealm from East to West and down into the South and burn every settlement of Apefolk they could find. Four queens agreed to the Plan and many warriors were assembled. And, happily, that worked! When the warriors flew homewards again, they could find no Ape settlements, no Ape gardens or fields throughout all the land. And thereafter, there was peace. But then a wonder happened the like of which Dragonkind least expected --- the Apefolk returned! And not only did they return, but they moved ever northwards with a vengeance! Like the Apes of your world, ours, too, had learned the arts of fire and metalcraft. And they seem to have developed a very strict anti-Dragon mytho-legendarium. We deemed there would be no peaceful coexistence with the Apefolk, even had we wished for such a thing! They came riding upon ponderous beasts and these bore weapons that could pierce even our sturdy hides! Terrible were the wars that they brought on us and many brave Dragons fell. Of the seven ancient realms, but two remained. And still the Apefolk came against us! They painted Dragons upon their metal skins, and those Dragons had mighty spears thrust through their breasts. The Apes had become fearless and dominant. The Wise had no counsel now. The queens' herzogs had no advice. I'm afraid that our lot was, at that time now not too long ago, much like yours is now, friend! Our choices were limited and it seemed that, difficult as it must seem, we must cede our world entire to the Apefolk, lest they destroy us entirely! Happily for us, we were still several hundreds strong --- more than enough to maintain a much reduced realm, safe from their predations. While it seems you are fighting the good fight without help! And so it came to pass that the young Queen of the realm of Sheharemard, north beyond the mountains, made a parley with the kings of the Apefolk. Difficult as it was to do, she ceded all the lands of the world south of the Wanlight Mountains to the kings and queens of the Apefolk. But the cold fields of the North would be Dragonhome. Apes must not cross the mountains, or else they will be burnt. Dragons will not enter the lands south of the mountains, or else they will forfeit the Truce. Of course, the kings agreed, but the lives of the Apefolk are short and their memories, seemingly, shorter still. Even now, the Apefolk regularly try to cross the mountains. Looking for "Dragon gold" they say. Fools! Anyway, the lesson, my dear friend, is simple: as we are doing, so you must! Stand your ground! Do not listen to the lowly snakes, peddling their ill-conceived counsels of appeasement and conciliation! Do not involve yourself in their realms or their policies. They are Apes, and you are Dragon. Their policies do not take our kind into account, except as far as our destruction. Involving yourself in their doings will only dull your wits and blind you to their greed and ambitions against you! No, there is no parlay with the Apefolk. They will ever try to kill you. Kings will send their brave knights out to hunt you and mount your head in their feating hall! Choose well your homeland and make a clear demarcation of the territory you will defend at all costs. Burn every Ape that sets one talonless toe across it. Make sure all the other Apes learn that lesson as well! Sadly, I fear that our plights will be the same. In time, sooner rather than later, you will be defeated: others have said true --- you must win every engagement, the Apefolk must but be lucky once! Just as I am sure that in time, perhaps later rather than sooner, our race, too, will be destroyed by the Apefolk. Even though we came to understand the threat very early on, and much earlier than you did, it was already too late to mount an effective defense against such a determined and pesty foe! Yet, be of good cheer! Is it not a liberating and exciting sensation? The resistance of wind beneath your wings? The cool rush of the gale through your feathers? The roar of flames bursting from your maw? The screaming of the terror filled Apefolk and the moaning of their dying? Live whilst you may and defend your homeland while you can! You are not guaranteed long life or peace. Make the Apes pay dearly for every foot of land they gain from you! And at the end of the fight, when at last you perched high upon the last crag overlooking the cold ocean, burn as many Apes as you can before their great spears pierce your thick hide and tear asunder your heart and let your last gout of flame burn the fools as they watch you plummet into the chill waters below! This is a fight neither of us can win, but in the end, it is a fight we can not let them win too easily; and you must not either! [Answer] You don't need to destroy humans. Alexander's answer is not a bad beginning, but not sustainable on the long run because - as Shard martin said - other humans would want to get rid of the threat, and one dragon alone won't be able to keep them contained, even with the help of a tribe who worships it as a god. So instead, the dragon should establish itself as a benevolent - or at least indifferent - god and not kill humans. Instead it should provide them with religious rituals which include plenty animal sacrifices to feed it and declare a land sacred on which it can live undisturbed. Maybe it could provide entertainment or military help occasionally. Or just tour all continents and participate in various religious festivals held in its honour. [Answer] For humans to congregate in dangerous densities requires farming and animal husbandry. The raw land alone can not support large densities solely through scavenging. Thankfully for you, the large tracts of land necessary for farming and animal raising are readily detected from the air, and easily disrupted. Also, by necessity, it takes crops time to grow. So, you show take a two fold tactic. First, is isolate a small land area, ideally separated by water, and simply eliminate them entirely from this land. You can use this as a primary food source. You may need reasonable diligence for this land to keep it clean. Next, start disrupting the farming and animal operations. You only need to do this for a couple of seasons, and the humans will start to die right out. The local animal populations will suffer during this time, but likely recover quickly once they're gone. Large quantities of humans tend to die off en masse, precisely because they over concentrate and overwhelm local carrying capacity of the land. If they can't mold the land to their needs, the population fails and dies off. If you let them get too far, this may take some time, but, truly, they can't maintain their population for long as long as you continue to disrupt their concentrated food sources. Start with the largest concentrations you can find. They will fall hard and fast, one to two years. Eventually they will scatter, and you can start a more precise campaign of eradication, continent by continent. They don't do well once scattered. If nothing else, they start to fight each other for resources instead of fighting you. So, breaking them up in to smaller packs is always profitable. Its important to try and pay special attention to those floating houses they make across the waters. This helps contain them, especially keeping them off your cleansed land. During the second phase of the campaign, pay special attention to those huts they build, especially the larger ones. Again, the goal is not necessarily to destroy them directly, but to destroy their food stuffs. Humans, like squirrels, naturally like to store and "save for winter". Nothing works better on a infestation than wrecking their food stocks when the snows come. The extra bonus of this technique is it requires inordinate amounts of energy for the humans to gather food and other materials, so they have less time to spend working on making pointier sticks to attack you with. They're too busy simply trying to dig up roots to live by. They will try crafty things. Putting stuff in caves, burying food, etc. But all that is more work. The more they work, the less time they have to work on developing new things. Keeping them scattered helps avoid them sharing information as well. The final benefit is you don't have to worry about some group swearing loyalty to only turn and betray your trust. They're not trustworthy, so don't even start. [Answer] Well, if your problem seems too bothersome to solve what you need to do is redefine it as something you can solve. Make it narrower. "Get rid of humans" is a bad problem because a) the buggers breed too fast as proven by your practical experience and b) which you have already seen but will only get worse over time, it specifically motivates the infestation to get better at surviving you. Instead you need to focus on the part that is the actual threat to yourself, their ability to attack you. First part of this is trivial and you probably have already done without mentioning it. You can fly, they can't. Destroy all approaches to your lair over land. You do not use mountain paths, so get rid of them. Make sure that only practical way to get to your lair is by flying or by literally building a path with lots of effort and time. Then make sure that you make the surrounding area forbidden to humans so that they can't get close enough to seriously plan attack on you. Make sure the forbidden area has some clear borders so that it is clear there it starts. Mark the borders with large boulders or something. Then tell any humans you see near the area that going inside the area will result in extermination and make good on that promise even if that requires bit of work. Humans are short lived, so within few decades the detailed knowledge of your forbidden area will be forgotten and planning an effective attack on you gets more difficult. It saves some work if you recruit your neighbours to protect your borders. A simple promise of helping them fight off enemy attacks in exchange for them killing people trying to enter your area would be a good deal for both and it is not like you mind killing humans especially when they are already close by. Second part is to stop them from developing weapons that are a threat to you. The solution is similar to the above. Draw a clear line, punish those who cross it with extermination, do **not** punish those who do not cross the line. Communicate the line clearly and trade with humans to share the effort of enforcing the rule. Fortunately there is a trivially simple and effective line for you to draw here and that is iron working. Bronze and stone will allow humans to exist comfortably and build their little kingdoms but limit their ability to expand and mass produce weapons. It certainly will stop them from developing an industrial base that would eventually allow military technology capable of threatening you for real. Destroy groups of people that use iron. Spare people without iron, tell them about your rule and if practical give them some way to inform you if their enemies use iron. You can probably afford a world wide network of informers to find out any iron users. But seriously use of iron on any significant scale should be detectable from air. You can just make a map of locations where the vermin mine for iron and cleanse those periodically. You can even make those forbidden zones such as described above. Not being sure which forbidden zone you are in and if there are more than one dragon would make killing you that much harder to plan. There is one additional ban you might want to enforce and judging by your difficulties have not considered yet. A ban on writing. Written records allow people to recall things known to previous generations and build on them. As such they directly reduce the effectiveness of your culls in reducing the threat humans pose. Embarrassingly this ban is difficult to enforce without human collaborators, so you would need to create some sort of "Dragon cult" and then spend some time interacting with the dirty monkeys. On a bonus side successfully enforcing this would pretty much remove any real threat of humans developing weapons capable of killing you. Well, they might trick you to entering a place rigged to collapse on you or use poison but those fairly simple to avoid. The dragon cult could also enforce forbidden zones and ban on iron, so it might be worth the annoyance. You can also make then gather you tributes of gold but realistically most of the gold would go to supporting the cult and its power. In fact, you will probably need to gather such tithes to make the cult work at all. [Answer] Two options: Scale Up or Collaborate. **Scale Up** Breed - the most successful way of dealing with competition is to strengthen numbers, and likewise evolve to meet the competition. The humans, with their fast breeding cycle, are very likely to evolve to a position where you become increasingly vulnerable. Likewise, while you can kill an arbitrary number of humans with no net effect, they only have to kill you (or weaken and eventually kill you) to eliminate you as a threat. **Collaborate** Stop fighting them, and become a useful collaborator. Hire your services, become a part of the overall long term solution rather than remain mutual enemies. As an incredibly powerful, sentient, war-engine you can effectively act as a king-maker, and thereby find those who see the economic benefits of having you on their side. Essentially, stop being the enemy and find a common enemy to work against. [Answer] Divide and conquer. Find some ruthless people who have good leadership/faction following. Offer power by means of assistance. Use them and turn them on non assisted faction. Eventually work your way through. Once a considerable population reduction is achieved, remove faction support selectively. Its more like playing warcraft + chess. Watch game of thrones for tutorials and inspiration. This method requires only lesser effort, more timepassing fun for a dragon, ability to show-off. Its basically a win-win situation. PS0: don't accept gifts from humans in form of consumables. PS1: Always select factions far apart from each other. PS2: Always have a random faction on guard duty. PS3: Never allow your factions to meet or mingle with each others. [Answer] If the situation is truly as bad as you've described then you need to make some hard choices. You can continue to act like you're the apex predator and world super power or you can cede Earth to the apes and go in hiding in some remote area. If you continue to act like a world super power you will eventually [die a violent death](https://en.wikipedia.org/wiki/Saint_George_and_the_Dragon) at the hands of these apes. After all you will need to successfully counter all of their attempts, whereas they only need to get lucky once. Due to their great capacity for innovation and superior numbers the odds are greatly in their favor over time. If you go in hiding the apes will either civilize themselves to the point where it is possible to peacefully coexist or kill each other off without your help. This is the pathway taken by several other species in my world ranging from [Bigfoot](https://en.wikipedia.org/wiki/Bigfoot), to the [Loch Ness monster](https://en.wikipedia.org/wiki/Loch_Ness_Monster), or even the powerful [Megalodon](https://en.wikipedia.org/wiki/Megalodon:_The_Monster_Shark_Lives). During your self-imposed exile these apes will no doubt develop more and more efficient ways to kill each other. As they increase their population density and become more militarily advanced they will either develop more and more advanced diplomatic skills in order to ensure their survival or they'll kill each other off. Regardless you will be in a better position to negotiate a peaceful resolution. As an aside it should be noted that once their military might reaches a point where it can overwhelm you easily your safety is greatly increased. This is especially true if you learn to communicate with the apes. Their ability to dominate you will make them feel more at ease with your existence. In this way you use their strength of arms to bolster your survivability. [Answer] Find the largest tribe you can, demand to see their leader, eat him, pick a child at random (ideally one that's easy to identify) and declare a entity vastly more powerful than yourself (i.e. a god) has tasked you picking mankind's rulers and slaying any who would oppose their divinely appointed rule. You are now a dragon, a pope, and can change humanity's leadership on a whim. [Answer] Well you can always destroy their heart, soul and brain. Seven Sins seems to be the answer to that. Spread Lust, Gluttony, Greed, Sloth, Wrath, Envy and Pride across the world. With this you don't have to kill them and they are less threat than chicken to you. Lust, Gluttony and Sloth will destroy new generation. Greed will destroy old generation. Wrath will destroy their intelligence. Envy will make them destroy other and themselves. Pride will stop their growth in all aspect. [Answer] Its too time consuming to keep clearing these humans yourself, and as a long-lived dragon its better to just take a few years or decades and develop a good permanent countermeasure to deal with your problem. As a creature on top of the food chain, you certainly have enough observations of the species that prey upon these humans and can also survive without them - especially unintelligent ones, such as mosquitoes. Have a breeding program to create highly lethal varieties that will doom humans with a single bite, and spread them throughout the continent. You may need to develop small regions for the pests to prosper (e.g. swampy areas with medium to high temperature) scattered across the continents. However, these reservoirs of pestilence will take far less maintenance than actively going around hunting the hairless apes yourself. With the initial culling you do to keep down the population, these humans won't get time to breed resistance or immunity to the airborne diseases that kill them quickly. So with a few decades of work, you're left with a planet that still has most of your favorite snacks etc., but the only annoying thing is a constant background buzz due to clouds of mosquitoes that have already made all the humans extinct. Those pests are now also dying out, after having sucked dry the vitality from several related species such as apes, monkeys etc. in a bid to find food. Naturally, your defenses and drastically different constitution make it a moot point that no mosquito can harm you other than the annoying drone of a large group (which is now dying out too). [Answer] You should probably start a secret order. This has upsides with becoming a god - religions change. And with starting a nation - which can be conquered. Operate a dense network of *brothers* in hierarchies of all dominant religions and governments of all important states. Help them with 10% of force and 90% of information (you've got to have a lot of it, being long-lived). Make them help each other while doing their jobs, especially with promotions. Make them invent complicated ranks and rituals. Make only a select few know the truth about you and make sure they never know each other. [Answer] If the humans were a controllable infestation then maybe you would have destroyed them already, but since they are obviously in great number it may be best to figure out how to make them stop wanting to advance there abilities to kill, the only way to do this however is to give such a great advantage to one puny "kingdom" that it conquers all the others! Well what extreme military advantage would be so great that that no army could stand against? Well sir, you are of course that great advantage! You see, the armies of men are great and powerful, but they have nothing that can fly. The advantage of a flying, fire-breathing lizard thing would we so great that no army of man could stand against it, every battle where you fly in support of your chosen kingdom will be won by them! And what is even better for you is that they will surely never kill you, oh you great dragon are the reason for the greatness and power of their empire, but even better for you is that now there is no humans fighting each-other and no humans fighting dragons and so there's no need to make better killing machines and so you are safe with their eternal primitive technology. [Answer] One should never underestimate the value of an outside threat. This is a lesson taught to us by our own granddame. You see, when humans first came to our planet, our race was in its decline. Our size was greatly diminished, as were our mental faculties and magic; only our granddame remained of our prodigious ancestry. Fortunately, she foresaw both the potential trouble these humans could cause us and a solution. You see, an interesting astronomical anomaly of our home planet is a sister planet that comes close to ours every few human generations or so. This never used to be a problem; but our granddame was crafty. In just a few short turns, knowing that this planet was soon to be making its approach, she conceived and crafted a magic device that, when she went to her death to place on the other planet, rained death on our own whenever they came close. Madness, you say? Ah, but I haven't revealed the catch: we alone possessed the fire necessary to defeat this death in the air; a fact which was not lost on the humans. Not only did they end up allying with us - they actually ended up using their own magic to enhance our capabilities, restoring to us some measure of our ancestral fearsomeness. And all we have to do is pretend to get along with these hairless apes, and they not only put up with our presence; they laud us as heroes and are as eager to just hand us food as they are to bask in our glory! Now, I'm not suggesting that you have to manipulate the stars. But surely there are other natural threats; or barring that, natural processes you can turn into threats that you can exploit to make the humans depend on you. For a dependent human is the only human you can count on to never even think of trying to get rid of you. [Answer] First you don't want to kill them directly. That's just using natural selection against yourself. Over time humans will figure to live underground (or any other survival method) and how to recover even faster after your attacks. **But it looks like it's too late for that.** They have kingdoms, which means they can write and have a history. Probably already evolved to survive your attacks. That's why you're feeling the need of new ideas contain them. Any method you use to eliminate them will result to making yourself less effective against them and them having greater incentive to kill you. If I were you, I would: * Immediately stop killing the humans. So they would not get even more experts at countering you. * Help them achieve peace using non-violent methods. So they won't feel the need to advance their weaponry. Hence more unlikely to ever be capable of killing you. * Start making friendships with them and let them get to know you. If they see you as a thing they won't care about your well being. But if you're friends, they will go out of their way to give you support. And protection if need be. + In general cultivate a culture of understanding and support among them. The less they struggle, the less dangerous they will become to you. And the more peaceful and kind they be, you will receive more love and support. The more they can rely on you, the more motivated they are to not cause you harm. And you can have your quite nap times after all. ]
[Question] [ Fran is on holidays to planet Earth. She is having difficulty coping with the local geometry. At this second Fran is thirsty. She can see a lemonade stand nearby. She knows a human would have no difficulty getting there. But she's worried of making a fool of herself or getting lost on the way. You see the lemonade stand is neither in front of or behind her. The lemonade stand is in one of the *other* directions. According to the guidebook, humans have a bizarre extra-sensory direction-seeking power.Their cities are built with this power in mind, and that makes them very tricky for people like Fran to navigate. Well, she'll look more a fool just standing around like this. Fran takes the first step. . . Drat! Where's the lemonade stand gone? Fran can't see it any more. She looks around. Oh, it's behind me! Fran turns around and makes her way to the stand. Phew! That wasn't quite so bad after all. Fran is no longer thirsty. But she's dreading having to make it back to the hotel before nightfall. . . . Fran, and every member of her species, evolved with no ability to tell left from right. Suppose she was facing North. She can easily find and move towards things to the North or South. She can tell is something is East-West of her. But she cannot tell which is which. Likewise she cannot tell the difference between North-East and North-West. Fran's holiday was fascinating but exhausting. She cannot fathom how Humans carry around so much extra information upstairs without going mad! She's glad to be back in her home city. **Question:** What does Fran's home city look like? In particular how are streets and corridors laid out to avoid people getting lost? How are roads laid out to prevent collisions? **Some Details:** Fran is typical of her species. She has the following attributes: 1. Between 10kg and 1000kg in weight 2. 0 to 10 limbs for locomotion 3. 0 to 10 limbs for dexterity 4. She needs to breath, eat, drink and sleep 5. One distinct 'front' end that processes food, light and sound 6. One distinct 'back' end for excretion Maybe every member of the species is the same size with the same number of arms and legs. Maybe there is huge variation between individuals. Feel free to modify the species as suits your answer. For example do you think there would be a difference if they has two left-right arms rather than the two arms being arranged one on top of another? Or would a species make sense to have only one big eye rather than pairs? **More Info:** Some humans have a similar condition where they are unable to distinguish left and right. One countermeasure they take is to remember 'left' as the side their wedding ring is on, and use that to navigate. Fran cannot by her nature use such a trick. She would certainly be aware that one side of her body has a ring. But since she cannot tell which side is which, it wouldn't help her judge which side to turn towards. If she tried she would just as likely end up facing the wrong way. [Answer] Fran is a naturally subterranean boring worm-like creature. Her cilia enable her to move forward and rotate. On her homeworld, the tunnels are bored with ridges or grooves that serve as affordances for forward locomotion, allowing her species to progress along the intended direction of the tunnel (forward) more easily (and conversely, making it more difficult to walk backwards). [![Fran walking forward along the floor ridges](https://i.stack.imgur.com/GDG79.png)](https://i.stack.imgur.com/GDG79.png) Because the species finds linear forward motion comfortable, their settlements, structures, and rooms are arranged in intersecting rings. Wherever two rings intersect, the being can either choose to continue moving forward along their current ring, or turn off into the adjoining ring. They don't need to decide whether to turn left or right (or up or down, as the case may be) to enter the adjoining ring, since their tunnels all have a natural "forward" direction determined by the ridges in the floors/walls. Cross-tunnel tracks at the junction of two rings might serve as natural indicators of which way to go if the being wants to switch rings. This keeps the decision to a binary (keep going or change rings) instead of a potentially confusing choice between the left tunnel and right tunnel or forward. (Hat tip to @Yakk for exploring this idea in the comments!) [![intersecting ring tunnels](https://i.stack.imgur.com/ZRvlZ.png)](https://i.stack.imgur.com/ZRvlZ.png) The ring-tunnels can be quite broad to accommodate multiple beings concurrently moving together, but should not be so large as to be confusing. Long, wide rings might serve as rooms for storage, recreation, and labor, activities which may at times require the beings to rotate or turn around as they undertake their tasks, but the important consideration here is that they **always** can tell whether they are facing forward or backward based on the design of the tunnel. **Forward and backward are the only two cardinal directions.** This limited directional sense could be further exacerbated by minimizing the effects of gravity on Fran's homeworld, so even up and down become less relevant. Extensive three-dimensional intersecting networks of rings compose the underground cities and streets of Fran's people. A human moving along such a network would be utterly confused by the homogeneity of each intersection and the overall structure's inability to conform to a rectangular coordinate system, but Fran's species has both an extremely good kinesthetic sense of forward progress and a knack for remembering the relationships and spacing between rings, allowing them to recall which rings intersect with each other, which entrances belong to which rings, and where they are at a given moment within the ring network. [![Ring network diagram of a settlement](https://i.stack.imgur.com/yZ5ax.png)](https://i.stack.imgur.com/yZ5ax.png) Note that Fran and her fellows don't need an accurate mental map of the network's layout *in physical space* to navigate the network; they instead need an accurate mental map of the *connections* between rings, which would look more like a tree structure or hierarchy diagram than a traditional map. [![Physical 2D map vs network hierarchy diagram](https://i.stack.imgur.com/LuP9U.png)](https://i.stack.imgur.com/LuP9U.png) (I hope you like my MS Paint doodles) As a final thought on this concept, since a troglodytic lifestyle doesn't necessarily lend itself to the evolution of great eyesight, Fran's species might have a dependency on olfactory markers for subterranean navigation, much like the pheromonal signaling used by ants or the territorial musk/urine marking employed by some mammals. The relative absence or overabundance of scents in an open-air city would add an extra level of navigational confusion for poor Fran. [Answer] There are a few [languages on earth](https://en.wikipedia.org/wiki/Relative_direction#Cultures_without_relative_directions) that don't have words for relative direction. Instead of they use absolute the directions North, South, East, and West to describe the positioning of things. For example; speakers of these languages when facing East, would refer to their "North foot" and "South foot", and if they turned 90 degrees would refer to their "East foot" and "West foot". The speakers of these languages have been successfully foraging in Australia for at least 40,000 years. If the lack of a concept of relative directions impaired their ability to navigate, the languages would have died out. Other design considerations would dominate the design of their cities, probably building around whatever was built before it became one. [Answer] How about the rationality of object persistence? She doesn't have to know left from right; she knows the lemonade stand exists and will continue to exist if it is out of her sight. Infants know this within a few months. Thus: Turn. Left or right, randomly chosen, does not matter. If the lemonade stand is no longer visible; rationality tells you it is behind you; and that is a direction you know. Turn around. If the lemonade stand is still visible, approach until this procedure must be repeated. # Fran's City Off hand, the easiest way to lay out a city is with one-way spiraling streets and one-way radial arms (freeways are side-by-side one-way paths; my city is roughly laid out this way: circles around, about 3 bisecting highways in different directions). Idealized, the species doesn't have to choose left or right, it is chosen for them as the only way to go. So for example; where the inward spiral turns in, you can only go straight or turn: You happen to be turning LEFT and merging with traffic on the RIGHT, but you don't have to know you are making a left turn, it is the only turn, and you don't have to know you are merging right, there is no other choice. When you exit you choose to turn again: You don't have to realize it is a RIGHT exit, you have no other choice for an exit: follow the turn path, or do not follow it. That is how you make it to an inner ring. I am presuming, of course, that evolutionarily speaking, no species develops that can literally walk **only** forward or backward; and this situation is more similar to some form of dyslexia; like not being able to tell lowercase "b" from "d". But dyslexics do not have trouble when there is no choice or the images are symmetrical: "A", "O", "X", etc. So I think the trick may be to eliminate choices that **depend** on knowing your left from your right. [Answer] I suggest rings. --- As I understand, you want a solution that does not depend on the anatomy of the creature. Although I am taking some assumptions that I hope you find reasonable: * They are land dwelling. No flying, no digging, no swimming, at least not without tools. * They have eyesight. * They have some level of intelligence, enough to recognize other individuals. The intelligence is the hardest part. I can assume that they can recognize symbols, so they can read numbers, so they can have street numbers… but if they can recognize symbols, they may put symbols for left and right and navigate using that. Therefore, I am ruling out systemic abstract symbols. Yet, I am allowing them to recognize their peers and common objects. **Note**: There will amounts of items that the creatures will be able to distinguish at a glance (for example you know that “AAA” are three “A”, you do not have to count them – did I just trigger you to ask how to develop a society where people cannot count?). Yet, as I said, I am being conservative on my assumption about the intelligence of these creatures. --- **First prototype**: Have a big tower in the center of town and build rings around. In each ring, it does not matter if you have to go left or right because you can always walk any direction and still pass each house in the ring. The problem with this solution is that it requires street numbers. The creature would look at the tower from an intersection (a connection between rings), there would be number signs and the creature would decide if it has to go to an inner ring (going forward) or an outer ring (going backward) based on the numbers. As I said, if you can do that, you can have signs for left and right. Therefore, we conclude that a single ring is ok, but multiple concentric rings probably not. --- **Second prototype**: Create separate rings, each with a central tower. In the tower, you can place symbols※. This time you do not have to know what symbol comes first or second. ※ Perhaps just use colors. Alternatively, Make rings dedicated to certain things, for example, a ring for restaurants can have a symbol for restaurants. As long as we do not use any symbols that have an inherent ordering that the people need to know which come first. Otherwise you are telling these creature can't tell objects apparts, I'm not going there. What you need to do is this: First to look at the tower of the ring you are. If you are on the right ring, walk around it, in any direction, until you find the destination. If you aren’t, go to the tower, from the tower you can see the other towers, find the one you need, and walk in that direction. The above would require the tower to have an elevated (but not necesarily at the top), freely accessible from any direction, open area, from where you can see above the houses in the ring. After you have seen the tower you need, you walk in that direction. To prevent the creatures to lose their sense of direction, the access points to the center area would need to be abundant. Or even better, design the houses so that you can walk over them. Perhaps on your way there, you lose sight of the tower; in that case, you will end up in a different ring. Repeat the process until you get there. --- Another problem is how to arrange the rings in space so that they do not block the view of other rings… [Nature has already solved this problem](https://www.youtube.com/watch?v=ahXIMUkSXX0). [It is similar to the problem of how to arrange leaves in such way that they minimize the light they block to the leaves below](https://www.youtube.com/watch?v=lOIP_Z_-0Hs). [More generally](https://www.youtube.com/watch?v=14-NdQwKz9w) [how to distribute items in such way that they do not eclipse resources to other items](https://www.youtube.com/watch?v=_GkxCIW46to). The solution is the spiral pattern we see in sunflowers: ***Pattern of dots in a sunflower behind a spoiler wall to mitigate eye stress.*** > > [![Sun flower pattern](https://i.stack.imgur.com/N9zuV.png)](https://i.stack.imgur.com/N9zuV.png) > > > Observe that in the pattern, from any given spot, the center of the other spot do not align perfectly. It is not a uniform tessellation. Instead they arrange spiral arms. Thus, if you imagine each spot as a ring, with a tower at the center, that tower will not eclipse the view of the other towers (well, unless the tower is too wide, there will be a maximum width given the spacing of the rings). [Answer] Turn towards the thing you want. If you don't see it, keep turning, you'll see it eventually. Now, it's in front of you. No problem. Walk forward. A species like this would constantly be orienting itself towards the things it wants. There would be constant spinning. Perhaps even an evolutionary tendency towards pirouetting in place, until they see what they want to get. So what would the streets look like on her planet? They would look like a circle rather than an axis. Constant guides, like arrows, would let them know what direction to go in. They can find anything on a street, they just have to keep going around. To get to the next street, you keep going around until you see the entrance to the next street, from one circle to the next. There might be straightways from one to the next, and there might be some things on it, but they would be clearly marked. I would think that there would be special orienting places where the spinning was allowed in order to chose a forward direction, which would be like turning. Landmarks will be a big deal. Directions would sound like this: Go to Jasper Circle. Spin towards the clock tower. In front of the clock tower spin until you see the side sign for the grocers. Once you can no longer see the grocers spin until you can see the red street. Follow that until Market Circle. Use the go around there to find the Lemonade Stand. Once you see the sign directly in front of you, spin until you see it. There will be no choice between left and right, the species is just forced to go a specific direction. How does this evolve? Well, nature has to be laid out this way. There has to be an evolutionary pressure that makes omnidirectional choices a bad, bad idea, and always facing front a good idea. EDIT: You said we should be free to redesign your species, so instead of the whole body spinning in place, why not just the head? (ignoring spinal difficulties with this, of course) They spin the head all the way towards what they want, then orient the body and go in that direction. [Answer] Fran doesn't have any sense of direction and can't distinguish right from left or north from east etc.. To compensate that she however has developed a perfect sense of height. She always knows at which altitude she is. **The City** Their city is built in a spiral that goes from ground floor on the outside the top in the middle. So that the city looks like the tower of babel. [![Tower of Babel (picture from Wikipedia](https://i.stack.imgur.com/k8F2x.jpg)](https://i.stack.imgur.com/k8F2x.jpg) Whereever she is in the city she always knows at which height she is and to which height she wants to go to. So she turns to go up the spiral or down the spiral. And if she turned the wrong way she always knows that she only has to turn around to go back down/up. [Answer] Fran is of a rather pitiful species that has been under a lot of specialized evolutionary pressure by an apex predator. In response, her species has developed the gift of 360° vision and total awareness that we humans can only understand, if proficient in artificial neural networks: See, there are perceptive neural networks that can tell you everything that's in a picture but not its location. Place a banana on your car, take a picture, feed the picture to such a neural network and it will instantly tell you "banana" and "car" are in the picture. It can't however determine where these items are. The fast processing comes at the cost of information about location, both of which are inherent features of the neural network's design. This may seem confusing to humans: Child play books that let you search for stuff in a picture are plain boring for Fran. One look and she knows everything that's in the picture like she had a mental list. However this ability helps in triggering the flight reflex early enough for Fran's species to evade the apex predator of her home planet. It is very much like the eyesight of flies with their faceted eyes. When Fran checked for the lemonade stand, she closed all her eyes (in contrast to a fly she is able to do that) in rapid succession and noticed it's location, when for a short moment it vanished from her mental list of things that are around her. So she can only check for direction, if she is willingly losing sight of what she's searching for. At the same time she feels like something isn't there, which she should know to be there on a whole different level than humans do. This position check is a voluntarily triggered action that employs multiple uncontrolled reflexes: One for each eye. From all the above the design of a city is obvious: Narrow and zigzagging passageways that only allow for few things to be seen at any given time. These passageways don't need to be underground, but ceilings help limiting the view to above. If you're walking along a passageway (which you navigate by touch of your antennae) and something pops up on your mental list, it will simply be further along the passage. That is, if it's not another traveler, who may be going faster than you, catching up from behind. It is therefore common courtesy to recite all that you see upon meeting someone. By the way, that's a lot more helpful, than stating the already obvious time of the day like humans do, when saying "good morning". It tells you not only, if the other one is coming from front (because he tells you something new) or behind (because he tells you thing that just vanished from sight) but also at least one of you will learn what's up ahead. [Answer] **They wouldn't as the species would have long ago gone extinct from extensive starvation.** As stated the species cannot feed itself, it can't find food reliably because it cannot navigate nor control its own movement. As described it cannot change direction to seek food even if it can perceive it. It must rely on pure chance to happen to physically encounter food. Changing direction to seek food is one of the most simple behaviors we know of, for good reason it is not difficult to wire and is fundamentally advantageous for any creature capable of motion and absolutely necessary for intelligent life. Worse yet this means they also can not avoid threats if there is a cliff to the left and it perceives it, this species has a fifty fifty shot of walking off the cliff anyway. If they have any natural predators they are even more impossible for the same reason. Also you are confusing not knowing the labels for right and left vs not having a concept of right or left. A species with no intrinsic concept of right or left has no voluntary control over its movement and thus would not be intelligent by any sense of the word. A species with only a problem with the labels would have no problem finding the lemonade stand, they might have trouble with giving or taking written or verbal directions, but not with actually finding it. The species described lacks even an intrinsic sense of left vs right. If you redescribed the creature as having a concept of left vs right but having some directional sense that does not work on earth, similar to how a magnetically sensitive animal taken to a planet without a magnetic field might have trouble navigating, that would be completely believable. But an intelligent locomotive creature with no ability to understand at least a 2D plane makes no evolutionary sense. [Answer] Every answer I see here violate, in some manner, the question being asked. Fran is stated as not being able to tell East from West as well as Left from Right. That is, if Fran is pointed East she is unable to distinguish this from being pointed West (other than what is directly in front or behind, due to some concept of "vision"). Ergo I think I know what Fran is. She is a being that has *precisely two light-sensing patches* on her: one fore, one aft. These vision patches are not capable of distinguishing objects. They're closer to being a laser range finder. She can tell the color, distance, and material of an object in front of her and behind her. But she cannot distinguish anything else. A red dixie cup would be indistinguishable from any other piece of red plastic. Furthermore these two vision patches *cannot move independently.* They are inextricably linked in a form of hard structural rigidity with both *each other* and her locomotive system. *Additionally* her locomotive system has no concept of "no, turn the other way." Turning is turning. There is no, "I see it, I see it, I see it, now I don't, go back" order that she can give to her locomotive system in order to reverse direction. Which means....she can only turn in one direction. So not only can she not tell which direction she's rotating *in* she has no control *over* it in order to turn around. She only has three commands as it were for movement: forward, backward, and turn. 1 At this point I've decided that there's no way this species would survive to sentience. Even a *snail* can tell that nope, that way is bad, turn the other way. Fran would have to be completely cylindrical (symmetrical around the up-down axis, the other two are irrelevant), for if she were not, she would get stuck up against a rock or a tree, unable to turn away from it, and then starve to death (or get eaten, or...) and rapidly go extinct. I have no idea what a city built by her people would even look like. Simple things like *hinges* would boggle their minds, because hinges would have to bend in a non-uniform way. We also have to do away with gears because those rotate non-uniformly when meshing with each other. At this point you have to basically discount every possible piece of technology above the stone age. Fran does not live in a city. She's a barely cognizant animal living on a vast rolling plane of grass with no carnivorous animals (or her species reproduces too quickly for it to matter). She's basically blind, deaf, can't move quickly (or at all), and almost certainly either an herbivore or a composter (i.e. feeds off rotting organic matter).2 --- 1 Even *this* violates the uniformity of movement: turning while moving forward and turning while moving backwards are *not mirrors of each other.* That is, if an object moves forward 1 unit and rotates local-left 1 unit and repeats this pattern, it will move in a counter-clockwise circle. If it moves backwards 1 unit and rotates left 1 unit, it will move *in a counter-clockwise circle.* This is important because it does not retrace the path, ergo moving forward and turning and moving backward and turning get you to different places and imply a directionality difference of left and right! There are only two ways to fix this: 1. make Fran unable to distinguish an object in front of her from one *behind* at which point all logic and reason have been defenestrated out of the building. 2. make Fran unable to rotate *while* moving, which seems like a very poor survival strategy Lets assume #2. 2 Dear god, she's a pre-Uplift [Traeki](https://en.wikipedia.org/wiki/Uplift_Universe). **Update 5-29-17** As some folks have expressed derision over whether or not mirrored vision is able to sense direction, I built a quick application to test that theory. The compiled executable is not very stable, but if you wish to try it out for yourself, [you can find it here](https://www.dropbox.com/s/n83c3ugpni8pf6k/Vis.zip?dl=0) (Windows executable, you assume the risks of running arbitrary internet code yourself). * Controls are randomized, but the keybinds for movement and look rotate are bound to WASD/IJKL in pairs (that is, W and S always perform inverse operations). * The initial boot will be in Vision Mode 0, which is as I have described above (only distinct along the vertical axis). If you can figure out what any of the keys do in this mode, good job. If not, then point proven: it is impossible to distinguish left from right in this mode. * Press Q to change modes. Vision Mode 1 is mirrored and Vision Mode 2 is human standard. Controls are shuffled each time the vision mode switches. * I recommend running in 640x480 as the mirrored effect has to pipe data off the GPU back to the CPU, compute, then return it (i.e. slow as all hell). This is also why the application crashes frequently. * I would have compiled to WebGL if it hadn't hung during the compile process (Unity bug?). In mirror vision you *can* navigate although identifying which direction is *objectively left* may not be possible, but it *can be distinguished from objective right* and a creature with this sort of vision would have no trouble tracking down a lemonade stand. You can watch me navigate the simple maze in [this video](https://youtu.be/7x5vrKQ_RTY) and aside from some orientation and forgetfulness over which key I need to press next (i.e. moving backwards instead of forwards), you can easily identify when I turn the wrong way briefly before correcting to turn the correct way. There are a few places were I made a decision based on knowing the actual layout of the maze (not having to investigate dead ends) but I think that it is sufficient proof that navigation under this mode of vision is possible and that leftness and rightness can be understood as distinct, even if not readily identifiable (that is, if the world were flipped left to right and the controls were flipped left to right, I would be unable to tell). That is, given [this perfectly centered view](https://i.stack.imgur.com/dc3qH.png), it is impossible to tell if the branch path is to the left or to the right. But by rotating [to one side](https://i.stack.imgur.com/dc3lF.png) or [the other](https://i.stack.imgur.com/hIcfT.png) you can see that in one case the branch is farther away from center and in the other, it's closer. And closer to center is "forward" and if that's the direction you want to go, then having it be forward is desirable, ergo the two rotations *are distinct* and can be labeled as such. On the other hand [this is just meaningless](https://i.stack.imgur.com/JLfue.png) and contains no directional information at all ([standard view](https://i.stack.imgur.com/RBL84.png) of the same scene at the same point in space and time). [Answer] Fran's species are a communal burrowing species, but more importantly they're solar navigators which is why she has to be back at the hotel by nightfall or she'd be completely lost. Their two key directions are "towards the light" and "away from the light" \*. Their cities are built along a straight line with a large artificial light at one end. Individual "buildings" are burrows dug straight down from the main route. Passing another person on the street is done by the one going away from the light going over the top of the one going towards the light. Overtaking someone moving more slowly is done much the same way, personal space is not a thing. Prior to their becoming a technological species they were mostly active in the cool of sunset and sunrise and remained in their burrows during the heat of the day and dark of the night, the cities were orientated East (sunrise) to West (sunset). Her Earth hotel is specially adapted for her species, having a large light at the top to aid navigation and burrows at ground level for accommodation. *\* These directions translate generally to "towards" and "away", for example, "towards the food" and "away from the predator".* [Answer] Great answers so far. I'd propose cities with a simple hierarchical layout, where all cities are build on the following principles: 1. Cities have a point of origin, which also serves as the only access into the city from the exterior. Cities spread south from the point of origin, with a main road going straight from north to south. 2. Secondary roads spread out from the main road, in alternating directions along the main road (but 2 secondary roads cannot converge on the same point of the main road). Secondary roads have their origin in the main road, and may NEVER cross the main road. 3. Tertiary roads spread out from the secondary roads, following the same rule as secondary roads. There may be lesser hierarchy roads, depending on the size of the city. 4. Given the road structure, no road may cross another, all roads are born in a higher hierarchy road, and may spread into lesser hierarchy roads. This means there are no road crossings as we know them, only points where new roads are born. 5. Buildings and sites along a road are also alternating (odd on one side, even on the other). 6. For an addressing system, they use a simple hierarchical reference, starting at the origin point for the city, and then numbering every road that must be taken to arrive to the destination. For example: * Address 'Lama-3' refers to the third building on the main road of city "Lama". * To get to address 'Copo-3-6-4-5', starting from the origin point of city "Copo", one would take main road, then go into the third secondary road, then into the sixth tertiary road, and then into the fourth quaternary road, and find the fifth building on that road. City maps would appear to have a leaf-like structure: [![City Map](https://i.stack.imgur.com/wvPh5.png)](https://i.stack.imgur.com/wvPh5.png) [Answer] The question seems to boil down to finding a realistic one-dimensional environment for animals still embodied in a fundamentally three-dimensional universe. I think it's impossible for an animal to evolve to have *no* conception of all three dimensions while living in the same universe as Earth. There's just too much of an evolutionary advantage to fuller navigation. But I think Thriggle's is the best approach to imagining how an animal might be *biased* to 1D motion. The structure of the underground city wouldn't have to be rings in particular--just a network of 1D pipes. One justification for this might be that tunneling forward or backward is easy, but left and right or up and down (all in the animal's local reference frame) is hard or impossible. This is analogous to how we surface-dwelling creatures tend to think in terms of 2D maps. Navigating up and down is less common for us, but very far from impossible. I imagine (but have no proof) that animals who don't jump or meaningfully climb (like beetles or turtles) feel this bias more strongly. But they still need to be aware of of predators (or prey?) who are more mobile! One side effect of this might be an even greater tendency to sort things along a single axis, ignoring multiple dimensions of variation. There is [evidence](http://www.cell.com/trends/neurosciences/fulltext/S0166-2236(17)30031-0?rss=yes) that we tend to employ a 2D conceptual grid for more than just navigation. I bet their politics would be even less nuanced than ours, which sounds frightening. At the same time, optimization in multiple dimensions (of which the unicellular chemotaxic food-finding alluded to by John is one example) can be sped up considerably by dimension reduction. This is why algorithms like Newton's method or gradient descent work. If the choices at hand truly do come from a one-dimensional submanifold of the ambient 2+ dimensional space, then it makes sense to treat left/right (and up/down) as equivalent. But, in the adversarial setting of evolution, as soon as you make this optimization and sacrifice distinguishing power in the transverse directions (e.g., small krill to eat are at the ocean's surface; protection from surface predators is down), some other creature will take advantage of your disability and outcompete you (just go around the stupid up-down whale). But you never did say the creature had to evolve this way naturally. This question reminded me of the company [QBotix](https://www.technologyreview.com/s/429087/a-robot-to-tilt-solar-panels/)--to save money on solar panel rotation motors, they make a robot that travels along a linear track, rotating each solar panel in an array individually. It only needs to deal with motion along a single axis, simplifying the problems of navigation and control considerably. Maybe Fran is a designed "organism" and the original design spec (say, autonomously navigating a Dyson ring for maintenance) had no requirement for freer movement. [Answer] # Fran is blind/omni-visional, knows how far away things are, and has a built-in compass Fran has no sense of vision. Either that or she cannot distinguish directions very well. It all comes into her mind as one big omni-directional sense of vision. Constant and always available 360° vision. She also has no sense of physical touch. Telling such a [person](https://en.wikipedia.org/wiki/Person) what is left and right is next to impossible. Fran however has a finely tuned sense of materials, objects and their function. She also knows their distance. She can instantly sense "Mmmm... lemonade... 3.141592 [decameters](https://en.wikipedia.org/wiki/Decametre) from here". Fran is also highly sensitive to magnetic fields. She senses the direction of the magnetic field lines. That means Fran has no problem navigating in terms of North, South, East, West, Zenith and Nadir. Some human cultures do that. So Fran can find the lemonade by simply starting to move and then adjusting her magnetic direction as she is essentially playing a constant game of [Hunt The Thimble](https://en.wikipedia.org/wiki/Hunt_the_Thimble) ("Hot & Cold" game) with herself. With this Fran will be quite capable of navigating her way around a human city. She will act a bit odd around people though as she quite often will not be facing people that she talks with. # What does her home city look like? It will be built on these premises: that the [sensory-motor coupling](https://en.wikipedia.org/wiki/Sensory-motor_coupling) will not be built on absolute knowledge of your position, or the relative direction of things... but on [cardinal directions](https://en.wikipedia.org/wiki/Cardinal_direction) and what functions and materials you have around you. Exactly how this looks you will have to work out yourself — [you are the world-builder of your world, not us](https://worldbuilding.meta.stackexchange.com/questions/4868/how-to-deal-with-i-have-a-high-concept-please-do-my-work-for-me-questions) — but here you have a concept that might work in trying to figure that one out. [Answer] Fran is an omnidirectional creature. For example, the earth equivalent would be a jellyfish or cephalopod. In Fran's native environment, they would merely point at the target, then "jet" using their native locomotion. On land, they can't do that, but merely flop around until they get to the location of desire. Natively, Fran's species would use a spherical coordinate system with their own senses point of reference, however, since that species is unstable on land, the coordinates are relatively useless, since even the point of reference moves on every attempt. [Answer] First, they can navigate by tall landmarks. (Salt Lake City, Utah is one place on Earth where the mountains make orientation easy and people seem to use cardinal directions often.) If there are none, they can build tall towers that are perceptibly different to navigate by if necessary. Giving them a magnetic sense is probably cheating, but there are the sun and stars. Second, they can build intersections that are not symmetrical, and do not meet at 90° angles. Even if they can°t tell which turn is left and which is right, they can still tell which one is acute, oblique and straight. Instead of rectangles, their blocks could be parallelograms and directions could be to make the tighter or wider turn. Or they could have rings of beltways, and directions would say to turn inward or outward. In some situations they might also use uphill/downhill. [Answer] As some other commenters noticed, Fran's species is artificial and was definitely created by some other intelligent being\*. This is pretty obvious because Fran is a highly intelligent, self-propelled rail car (locomotive?--my rail terminology is a little shaky). (\*Some people speculate that the creator was another species on Fran's planet before Fran's species, unfortunately that species seems to have died of problems caused by over-population shortly after the planet was completely covered with autonomous rail transportation.) Her city is a collection of rail yards (residential areas), with an extremely complicated switching system. The switches are controlled by some kind of electrical means, and Fran has an ability to operate them through a broadcast organ (wireless modem). On her home planet, when Fran wants to go from her house to the lemonade stand, she opens her front door (by wifi) and activates (by wifi...) the rail switch in front of her house (which happens to face in the direction she calls "westbound") to connect her house to the Blue 5 Westbound line (the street she lives on\*). (\*Side note, she lives on the Blue 5 line, meaning that her house [which is a straight line] is parallel to the Blue 5 line, when she goes out her front door she ends up on Blue 5 Westbound, if she goes out her back door she ends up on Blue 5 Eastbound. She doesn't turn around to do this, because she is equally comfortable traveling backwards and forwards, even though she can tell her front from her back.) As she travels along Blue 5, she knows the lemonade stand is in the downtown area and she will need to take Red 3 to get there. So when she nears the junction of Blue 5 with Red 3, she activates the rail switch to join Blue 5 Westbound to the Red 3 Downtown line. While on Red 3, she catches up to a couple in front of her who are traveling slowly and holding hands (they have joined front to back). She travels at the same speed as them until they reach a siding and make way for her. She reaches the lemonade stand, transferring onto the siding it is located on, gets her lemonade, and then returns home by traveling in reverse the whole way. On Earth, Fran really is in trouble! She can still move forward and backward, kind of, but her wheels aren't necessarily pulling evenly due to terrain variations (normally this is corrected by the rails, but on Earth she doesn't have rails). Even if she moves forward and backward until random chance turns her in the direction of the lemonade stand, she will still have considerable trouble getting there since traveling straight toward the lemonade stand will result in slight random curves in her path. Really, it is amazing she got there at all much less back to her hotel. In the future, I would advise Fran to stick with the guided tour, where visitors from Fran's planet are placed on vehicles (possibly using a really gigantic electric claw game type grabber) and a tour guide from Earth drives them around--or she could just stay in the train yards, if the gauge is the same or if she uses some kind of rented adapter to let her run on a different gauge. [Answer] All answers so far fail to address one basic problem with Fran. The question describes her process of movement: "Fran evaluates positions of objects. Fran takes a step in a randomly-chosen direction. Fran re-evaluates positions of objects." But for every creature on Earth, movement does not work that way. We continuously evaluate our surroundings (even if that's by touch, vibrations, echo-location or whatever) and continuously evaluate our movement around our surroundings. Unexpected things may happen, but there is not normally a gap in perception. Fran therefore has a body whose major feature is that any movement prevents vision whilst that movement is taking place. Possibly her species has ultra-low blood pressure and cannot sustain multiple activities at the same time, so she blacks out during the process of moving. Or maybe she detects objects with vibrations through the ground, so she needs to be stationary with her feet in solid contact with the ground to "see" again. Both of these scenarios though present a basic problem for the question. Creatures with non-continuous vision tend to evolve extremely good mental models of the space around them and their position relative to it. More that that, it's a skill which can be learnt by blind people and animals, so evolution isn't necessarily required. [Answer] Have you tried giving directions to an islander? Specifically someone that was born and raised on an island; Tahitians (the one from my personal experience told me that they didn't drive into the city as it was really disorienting) don't always do maps very well. Their directions are: go towards the mountain, then at this object go towards the ocean. Several mountains help as do tall buildings, religious structures. In addition, everything has an object/feature in their body that connects to something. Heart-side (aka left to us) or from the longest tentacle towards the smallest. Maybe they think in Radians and not all this silly limited connotations that humans use because they lack their internal compass/accelerometers/gyroscopes. Culturally, there has to be directions or they will never visit anywhere as they could not get off their planet. How could everyone get together to build their spacecraft? [Answer] Fran civilization don't build cities, because Fran race has extinguished as soon as it began evolving. What most of the answers here are trying to ignore is that what you are describing is not someone who get confused by left and right like a child could, but it's clearly explained in your example that she has no ability to physically sense directions other the front and back. So she is not able to turn. She knows where is front and where is back, but not being able to sense what stand in the between, she has no way to turn. Or, to be generous, she can turn randomly. Let's use a compass: she is facing 0 degrees, so she has 180 degrees behind her. She try to turn right, so now she is facing 1 degree, and behind her it's 181 degrees. 180 degree exist no more, she has no concept of it anymore. Even more, to move from 0 to 1 degree, she needs to rotate in a direction that do not exists for her. But she cannot consciously turn in a direction that do not exists for her, she has no reference for it, she can't sense it at all. Beware: you clearly say that she cannot even distinguish the sides of her body. She cannot, in any way, turn in a meaningful mode. So her race can only move in one constant direction, or randomly scatter around. Her race, at best, survives because they are small virus living in a huge pool of nutrients. Cities? No way. Lemonades? Even less. [Answer] The species is nocturnal, they evolved on a planet with an extremely strong *aurora borealis*, and the continent they evolved on lies fairly near the North Pole. Except in extremely bad weather, you can always tell which direction is north because that's where the sky is lit up. So they use north, east, south, west. On their home planet, if they go out during the day or in extremely bad weather, they navigate by landmarks (and quite often, they get lost anyway). They have colonized continents that aren't near the North Pole, and there, they erect a lighthouse to the north of every city which is lit at night. Extremely large cities may actually have several lighthouses, which can easily be distinguished. They use whichever lighthouse is most directly to the north of them to navigate. [Answer] What if Fran were a water-based creature with either some control of her physical structure or some kind of inherent structure. All her sensory organs are inside her outer boundary, including her "eyes". The eyes see everything in a 360-degree disc (or possibly 360-degree sphere). Possibility 1: Her locomotion is fluid-like.. so a flowing mechanism. Traveling "downhill" is quite easy for her. Traveling "uphill" is easier than side to side because she leaves a moist trail in her wake. Traveling over moist surfaces is easier for her than dry surfaces. Possibility 2: Alternatively, because of the nature of her sight, this liquid-like creature only perceives the world as "forward". So while Fran can move as easily as you or I on a two-dimentional plane, whatever direction she's traveling is always forward to her. There are many ways to structure a city for this kind of Fran. If you go this direction I'm sure you will have fun exploring the possibilities. ]
[Question] [ [Humans as Pets](https://worldbuilding.stackexchange.com/questions/6550/humans-as-pets) is now a thing. But not for AI (as in the linked question) but for the aliens. This celebrity was seen with their human pet and now every alien kid is begging their parent to get one human as a gift for their next hatching anniversary. Alien morals work differently from the human ones, so they decided that "as long as no one notices, we can provide ourselves as many humans as we like." So the question is: **How many humans can our aliens abduct without being noticed?** * Aliens equip "cloaking devices" to their ships, so they can visit us without being detected. * Our aliens are not racist, so they will abduct anyone. * Aliens know how our Earth works, so they will focus on "under average Joes". * We want to abduct as many people as possible. * But also, we want to stop at a point when majority (65%) of people will start to think that "this is very weird". * After that, the aliens stop. They can breed other humans on their home planet anyway. But we need to cover the demand. [Answer] **If you hit up the developing world, potential abductions could number in the tens of millions.** The developing world has a huge number of people who have negligible economic importance and live in countries that do not or cannot keep track of all their citizens. From the [World Bank](http://www.worldbank.org/en/topic/poverty/overview): > > This means that, in 2011, just over one billion people lived on less than $1.25 a day, compared with 1.91 billion in 1990, and 1.93 billion in 1981. > > > So from this large pool, the aliens should be able to get plenty of pets. Abduction Strategy: * Target young men and women in remote, economically depressed villages. It is common for them to leave for the big city. They will be missed but those who remain will think they just left for the city and didn't tell anyone. Or grab those who have already left. * Find out the missing persons rate for a given country, if known, and keep your abductions within the statistical tolerance for that rate. * Not all humans are equal. Alien children will have preferences for a given age, gender and skin color for their pets. Some humans are easier to abduct without detection. If the alien children want educated white females from the developed world, the supply will be considerably smaller than dark skinned males and females with no education. * Warzones are especially good places to abduct humans as accountability in those areas is especially low and there's an existing narrative to cover the absences. ## **Build a breeding population** Based on [this answer](https://worldbuilding.stackexchange.com/a/18277/10364), the minimum population of humans without special attention to genetics is 5000 individuals. Abducting this many humans is trivially easy and far below the detection threshold. While pet production from this population would be incredibly slow, pets from this population can be sold as boutique pets, specially bred to be pets, far better than pets caught in the wild. [Answer] Judging from this: <http://www.unicef.org/media/media_81518.html> your aliens could drop into a town in Nigeria, shoot half the adults, abduct absolutely everyone else, Boko Haram would get the blame and the enslaved children would be *better off* than if it actually had been BH. Or you could go to Yemen and simply abduct people at gun point. So long as you looked like a human no one would suspect a thing! But that's taking the third world approach that all the other answers did. Let's try going for the more expensive option. The UK deals with a missing person report about once every 2 minutes - 306,000 a year (<http://www.nationalcrimeagency.gov.uk/news/475-one-recorded-every-two-minutes-missing-persons-figures-released>) - with "almost 97% being found safe and well". That's about 10,000 actually disappearing each year. I reckon you could nudge that up by 1K and people would invent an explanation for the rise. 3K and people would stop guessing why and start trying to work it out. So even if we assume the whole world is as ordered as the UK: UK population: 64 million. Number of people who can vanish before you attract attention: maybe 2K? World population: 7000 million. Number of people who can vanish: **200K**. If we assume the world is as ordered as Chad or Sudan, however, then I'd say at least 100 times that many before it stops being blamed on warfare and religion, making **20 million**. Reality will be somewhere between those figures. **A couple of million**, say. Give or take a zero, that sort of number. [Answer] > > The flow of desperate migrants from Syria and North Africa hoping to > reach Europe is already much higher than in the same period in 2014. > > > Germany, which receives by far the most asylum applications in the EU, > is expecting 800,000 refugees to arrive this year. > > > <http://www.bbc.co.uk/news/world-europe-24583286> > > > There are many gangs of people-smugglers who are taking advantage of such migrants. The aliens could replace or employ the people-smugglers to divert the migrants to them. European governments would feel relieved that they no longer had to deal with the influx and so might not be motivated to investigate too assiduously. Alternatively the aliens could simply turn up with a space-shuttle that has been disguised as a train or bus and is marked "To Europe" in the local language. They will literally have people (usually with no identity papers) fighting to get on it, no questions asked. [![enter image description here](https://i.stack.imgur.com/iroWu.png)](https://i.stack.imgur.com/iroWu.png) <http://off-guardian.org/2015/07/23/thousands-of-refugees-flee-northward-from-greece/> [Answer] They can abduct over 50k people easily. They first need to check out the countries in war, and pick one of them. It'd be better if they had nuclear weapons. For example, North Korea and South Korea are at war. A cold war, but it is declared. Also North Korea has nuclear weapons. Actually, [now is the perfect time](http://www.mirror.co.uk/news/world-news/north-korea-warns-will-attack-6290303). They first abduct the humans there, very, very quickly. Then, they act like one country bombed the place where they abducted them. According to the [Wikipedia page about Hiroshima and Nagasaki Explosion](https://en.wikipedia.org/wiki/Atomic_bombings_of_Hiroshima_and_Nagasaki) states that `70,000–146,000+ killed` in the Hiroshima explosion. So we can think that ~70,000 bodies were found and ~76,000 wasn't (146-70), so instead of vaporizing ~76,000 people, they can just abduct them. [Answer] # Abduct the Abductors These aliens have all sorts of advanced technology right? They can easily find all the nasty people, and remove them from the populations that keep statistics of missing people. They'll then be able to abduct more people and still make the statistics look flat. [Answer] Because this is so profitable, a new strategy has arisen by Human-Pet Corp. that allows huge numbers of pet extractions per year. 1) They have extended fast growth biotech that allows them to grow a replacement body in 24 hours. The body is not viable as a pet, but makes an excellent human corpse to replace the abductee. 2) They have added a global monitoring network that allow them to detect humans near the point of death. By detecting this over 24 hours in advance, they can quick-grow a replacement and make the swap before the person dies. 3) Their advanced medical care allow them the ability to restore the pets to full health and market value in nearly every case. Even old-age is not a problem for their health care. 55 million people die each year. Human Pet Corp can salvage about 50 million of these. Best thing is, the pets are grateful for their new lease on life and since so many of them had a miserable existence they are totally happy and think they have gone to heaven. Just not the heaven they were hoping for. [Answer] Sure, anybody can kidnap humans from countries wracked by poverty and civil war, but you're trying to supply premium-quality humans from an affluent society with a strong school system. How about [Japanese people](https://en.wikipedia.org/wiki/North_Korean_abductions_of_Japanese_citizens) and [South Koreans](https://en.wikipedia.org/wiki/North_Korean_abductions_of_South_Koreans)? Dress up as North Korean agents, and leave enough clues as to what country did it but not who in particular. South Korea and Japan will blame North Korea. North Korea will deny it. They might think that they did it, but don't want to acknowledge it, or they might think that Japan and South Korea are deliberately exaggerating the extent of kidnapping. No-one will think the situation is weird. The only risk is the TV Trope "[Not Me This Time](http://tvtropes.org/pmwiki/pmwiki.php/Main/NotMeThisTime)": if North Korea decides to be completely honest with Japan and South Korea, listing all of the cases where they did kidnap, and who they didn't. [Answer] # All of them (or at least as many as they want) Depending on how you define "as long as no one notices", aliens could come and take anyone. There are current 6 billion people on Earth, and Earthlings are by and large, [prolific breeders](https://en.wikipedia.org/wiki/19_Kids_and_Counting). [Earthlings go missing everyday](https://en.wikipedia.org/wiki/D._B._Cooper), [even children go missing](https://en.wikipedia.org/wiki/Lindbergh_kidnapping), in fact [heads-of-state have been known to disappear](https://en.wikipedia.org/wiki/Harold_Holt) without a trace and will relatively little fanfare over a long enough time frame. Grimly enough, [Earthlings do a good enough job of wholesale "person disappearance"](http://womennewsnetwork.net/2012/02/07/india-girl-infants-murder-femicide/) that alien intervention could be explained to the appropriate Galactic authorities as a charitable act. Given how adaptable humans are to very minor changes over time, and given that an abduction would probably leave a bit of a mess, at first it would be chalked up to a minor localised crime-wave. I mean no one would thing to look at missing persons across the globe to see a spike in missing people all around the same time. Its also important to know that birth-control is an issue for humans, not population sustainability. In the third-world childbirth rates need to be high enough to combat infant mortality and produce a high enough population for subsistence farming. Its highly likely that humanity could easily produce enough pets without denting the global population Obviously the more famous the pet you want, [the more it will cost you](https://en.wikipedia.org/wiki/Jimmy_Hoffa)... [Answer] Continuing with the migration / refugee idea, you could abduct boat-loads of migrants at a time currently crossing the Mediterranean Sea. Anyone who noticed them missing would just assume that their boat has sunk as is tragically happening at the moment. Could be done out of sight of everyone and with minimal investigation. [Answer] Take a look at this link [NCIC Missing Person and Unidentified Person Statistics for 2013](https://www.fbi.gov/about-us/cjis/ncic/ncic-missing-person-and-unidentified-person-statistics-for-2013). Who knows, maybe some part of this persons are abducted by aliens, and we don't know it? If aliens breed humans, they need to have at least 20.000 persons to prevent inbreeding (see <https://en.wikipedia.org/wiki/Minimum_viable_population>), sorry, i was unable to find link for 20k, it was explained for me in colledge, but i have forgotten the details. So, probably aliens need to abduct healthy males and made them fathers for many children. So, i think majority of healthy males/females disappeared can be victims of abduction. UPD: if i was an alien, i would try to abduct solitude and condemned, likely to disappear to obvious means (not linked to aliens), persons - solders during war, sailors in sea (and sink the ship), passengers of planes just before the plane crash, tourists in wilderness, homeless persons during winter, orphans. UPD 2: other link [missing persons](http://www.usatoday.com/story/news/nation-now/2014/09/23/missing-persons-children-numbers/16110709/) [Answer] Check recent news reports about mass graves at migrant camps. There are thousands of dead victims of human traffickers that have been found - it doesn't take much imagination to think how many haven't been found because they were better hidden. And in order for there not to be mass panics and for people to keep using the traffickers, there would have to be a reasonable prospect of getting to your destination, so many more people would be in transit. They've already disappeared, as far as anyone knows. The sad fact is that there's no need for the aliens to set up a breeding population on their own world. They could easily take tens of millions of people every year from around the world without anyone noticing, and those people would almost certainly be destined for a better life than where they were. Unless they choose to breed for particular characteristics, or unless transportation is particularly expensive, it'd be much easier just to keep picking them up. [Answer] About 1/4 million per year - that's how many people are missing (20 year average) according to <http://www.scoop.co.nz/stories/WO1308/S00441/4432880-missing-persons-vanished-in-past-20-years.htm> If you increase it gradually enough, I think pretty much any number - we get used to things pretty quickly. If you kept it under (remaining population)/(Dunbar's number) per decade, and had it evenly distributed, then most people would know about 1 person missing per decade - not enough to raise suspicion. Dunbar's number is a "suggested cognitive limit to the number of people with whom one can maintain stable social relationships" (from Wikipedia), and varies, but is usually considered to be about 150. This comes out at about 45 million. As I mentioned, you'd need to ramp up to this gradually. Depending on how much intel you have, you could increase this substantially - anyone who has not spend X hours with other people in the last month; wars are pick & mix; anyone out at sea; in storms/floods/earthquakes. Any situation where personal communication is down for a period. Grab the odd plane; mountain climbers etc.; people with depression. Or, induce depression first, wait a while, then grab them. Monitor mass media carefully, if there are any reports, stay at that level for a while - people will get bored of the news if it comes up regularly. If you can replace them with fake corpses, it's even easier. Replace a pile of prostitutes with fake corpses (optionally framing someone), wait for the news story to hit, then start introducing "copycat killings" - wait for that to hit, repeat, repeat, repeat. Gradually generalize who gets killed - start with someone cliche (prostitute), then each "copycat" takes a different aspect from the newspaper - one "copycat" may target women, another the clientele of the prostitute, a third poor people; in the next generation, women becomes professional women, clientele becomes men in general, poor people killings are "copied" as African-American (implying a racist element). Each subsequent "copycat" takes one element from the mass media reporting, and so over time mutates the target. [Answer] In [this](http://www.gateworld.net/sg1/s7/705.shtml) episode of sg1 the computer revises everyone's memories as they remove them from the population: > > Over 100,000 people used to live in the dome. As the power level drops, the computer shrinks the dome and kills excess people by making them leave the protected area. To keep the people level-headed during this process, all memories of the people who departed are removed from their minds. > > > [Answer] In addition to the answers about taking refugees and people from developing countries, a significant number can be abducted from developed countries too, as long as you stick to the already downtrodden. There have been several incidents of serial killers targeting prostitutes (think Jack the Ripper, se fx [this list](https://en.wikipedia.org/wiki/Violence_against_prostitutes) on wikipedia). It would seem that authorities are mainly alarmed to these kind of killers when bodies start to heap up. So a serial abductor not leaving bodies behind would be able to snatch a much larger number before anyone got suspicious. Add to that targeting runaways and drug addicts, and from several, if not all cities at once, and you have a huge number. [The Colombian serial killer](https://en.wikipedia.org/wiki/Luis_Garavito) that admitted to killing 140 children is suspected of killing more than 400. Again, if the bodies hadn't showed up (and he had snatched a child that wasn't an orphan), nothing would have happened and he wouldn't have been caught. At least according to the documentaries about him that can be found. And he only worked in one geographical area. Multiply this by the rest of the world. [Answer] Lot of answers here are assuming that abducting people from developing countries will be easier but what they are forgetting to include is the Cultural / Social aspects of developing nations. In general, people in developing countries are socially very well connected and people know about each other a lot. So if Aliens abducts people from there , other people will notice soon. If the authorities will care for those missing people, is a different question. [Answer] You can get millions of healthy, educated pets in one swoop. Drop a big rock on one of the modern, major cities of the world. Grab everyone close enough to ground zero that their bodies likely wouldn't be found. [Answer] Many people mention 50,000 people for the minimial viable population for humans, but a study by [an anthropologist at the University of Oregon](https://www.nbcnews.com/mach/science/how-many-humans-would-it-take-keep-our-species-alive-ncna900151) actual puts the [number of humans needed to maintain the species around 14000](https://ui.adsabs.harvard.edu/abs/2014AcAau..97...16S/abstract). One man and professor named Frédéric Marin even says that the number could be as low as [98 people](https://arxiv.org/abs/1806.03856) for a viable population under the right conditions (people don't die, incest is avoided, etc.). It would be easy to get these numbers with very few people noticing. You could get this numbers in one day or even a few years just kidnapping people from a single major city. [3,900 adults are reported missing annually in Los Angeles](https://www.lapdonline.org/lapd_adult_missing_persons_unit) alone and over [600,000 people](https://nypost.com/2020/07/04/why-hundreds-of-people-vanish-into-the-american-wilderness/) go missing every year in the United States. With the right techniques, a lot of people could be collected - more than that [14,000 person threshold](https://www.nbcnews.com/mach/science/how-many-humans-would-it-take-keep-our-species-alive-ncna900151) - without the aliens being noticed. Plus, if they have the right methods/medications to make men forget their kidnappings or barely remember what happens, they would even need to permanently steal most men. Simply snatch up some men, take and preserve their semen, and release some of them back into the wild or some remote part of the world where they can go back to their normal lives. Since you use proper methods to make the men not perfectly remember their kidnappings and make sure each kidnapping happens under different circumstances, the police questioning the kidnapped person might not get much information from the victim. The aliens could take advantage of climate change and grab [climate refugees](https://www.pri.org/stories/2018-12-11/un-compact-recognizes-climate-change-driver-migration-first-time) caused by extreme weather events. In they want to collect their pets faster, they could cause a disaster by dropping a meteor on a heavily populated area or in the ocean and creating a tsunami in order to create a disaster which would force people to move from the region they live in. Many of these environmental emergency migrants - people who flee [temporarily due to an environmental disaster or sudden environmental event](http://climatemigration.org.uk/understanding-a-slow-disaster-getting-to-grips-with-slow-onset-disasters-and-what-they-mean-for-migration-and-displacement/). (Examples: someone forced to leave due to a hurricane, tsunami, earthquake, etc.)- could be taken as pets with few people being too suspicious about their disappearance. Once you get close to 20,000 people or even only 100 people, the aliens will have enough homo sapiens for a viable pet population. ]
[Question] [ Which body in the Solar System is the best candidate for being an artificial construct, placed there by a [Kardashev Type II Civilization](https://en.wikipedia.org/wiki/Kardashev_scale)? Some notes: * The purpose of this body is to monitor earth, with as little likelihood of detection as possible until Earth reaches Type I status. * "Major" in this case means well known to the astronomical community and somewhat to the public in general (a planet, moon, dwarf planet, or large asteroid or comet). I am looking for a specific, named body. * This must be a body that we can observe right now. No fictional planets or ninth planets allowed [Answer] **They could use any [Near-Earth Asteroid](https://en.wikipedia.org/wiki/Near-Earth_object#Near-Earth_asteroids).** These are asteroids that are in the vicinity of the Earth.They only last for a few million years, but such a civilization could easily install some stealthier thrusters (like cold gas thrusters) to use when not in view of the Earth to increase that lifespan. Being near to the Earth means that whatever tools they use to monitor the Earth would have an easier time seeing it, while there are so many Near-Earth Asteroids that this would not draw too much attention. Note that there is a risk of people attempting to use it for materials and discovering that it has advanced science equipment on there, but this risk would be small if it looks like a normal Near-Earth Asteroid until people actually start trying to build a dyson swarm. [Answer] ## [Earth itself](https://en.wikipedia.org/wiki/Rare_Earth_hypothesis) There are lot of unique planet properties that are too good to be conincidence and are usually explained via [weak anthroptic principle](https://en.wikipedia.org/wiki/Anthropic_principle), such as: 1. Lots of water in its best chemical state, thanks [to optimal distance to the Sun](https://en.wikipedia.org/wiki/Circumstellar_habitable_zone) 2. [Magnetic field](https://en.wikipedia.org/wiki/Earth%27s_magnetic_field) protecting life and water from solar winds 3. Just enough volcano activity to provide chemical factory for life, but not for destroying it. and many others So many unique properties makes more realistic synthesizing habitable planets than searching them for single-galaxy civilization. We could imagine that some of the unexplored places at ocean bottoms or under earth crust have some signs of planet synthesis or designed for collecting and transmitting information about the current life state. Some of that signs could be right before our eyes, yet we could not distinguish them from natural, due to lack of knowledge of planet design on cosmological level. [Answer] L4 would be a good place. Asteroids at L4 are called [Trojans](https://en.wikipedia.org/wiki/Trojan_(astronomy)). Earth trojans could maintain an orbit that doesn't go behind the sun relative to the Earth. There is one Earth Trojan: [2010 TK7](http://www.minorplanetcenter.net/db_search/show_object?object_id=2010%20TK7) ([wiki](https://en.wikipedia.org/wiki/2010_TK7)). It orbits the sun taking one year, but is ahead of the Earth, allowing this orbit to be stable. Its actual position, relative to the Earth does change, it loops in a "tadpole" shape relative to the Earth (its actual orbit, relative to the sun is elliptical, only relative to the orbiting Earth is the orbit tadpole-shaped). Bringing it closer and further from the Earth, but never nearer than 50 lunar distances. **Good points**: it stays roughly the same distance from Earth, not getting too close, or too far; continuous monitoring should be possible. It is a good size, about 300m. Big enough for a data centre and transmission equipment. Small enough to be hidden and not take an unreasonable amount of time to build. **Bad points**: Its orbit is not very stable, in the longer term it is chaotic, it is possible for it to flip from ahead of the Earth to behind the Earth (with periods behind the sun) In the much longer term it could get too close to the Earth and get ejected (or worse) however, station keeping every 100 years or so could keep it stable. It doesn't get close enough for detailed observations, though this would depend on the type of equipment you installed there. Another object, with a somewhat similar orbit is 3753 [Cruithne](http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=3753). It is in a 1:1 resonant orbit with Earth, and has been for quite a long time. Its orbit takes it further from Earth, but it never goes completely behind the sun, so Earth stays visible at all times. Its orbit is likely to be more stable than 2010 TK7, and it has some reputation (it has a proper name and has been mentioned at least twice on QI - satisfying the "somewhat known to the general public" criteria) It is also larger, about 5km across. [Answer] Consider a [**short-period comet**](https://en.wikipedia.org/wiki/Comet#Short_period) (specifically, [Comet Encke](https://en.wikipedia.org/wiki/Comet_Encke)). Pros: * Very short-period comets can have orbital periods of only a few years, with approaches relatively close to Earth ($\sim0.1\text{ AU}$) happening every couple of decades. * Comets *will* spend some time away from Earth, and may thus escape the watchful eye of people worrying about asteroids that could hit the Earth. This is an advantage over Jarred Allen's excellent choice. * Comets can fragment, so if the species wanted to send a scout ship to Earth, it wouldn't appear to be much different form normal cometary behavior. An asteroid spontaneously breaking up, though, would look suspicious. It might be harder to observe Earth when the "comet" is further away, but this may be an advantage, as it would be much harder for people on Earth to see that the "comet" isn't actually a comet. In addition, using multiple "comets" could mitigate this. --- ### Other notes It seems that all of the answerers to date agree that the object in question should be small. There are a few good reasons for this: * Small objects may be harder to observe from Earth unless they're much closer. They can tumble erratically, for instance, so tracking a point on the surface isn't easy. * It's not easy to land probes on them. We've done it before - you may recall the Philae lander recently - but you can't put a rover on them like we can on mars or other large bodies. These two criteria mean it would be harder for us to figure out that these bodies are artificial. * They can be closer to Earth than larger bodies can. This is why you don't pick, say, Jupiter, which would be much farther away than any of the choices we're picked so far. * It's easier to build a small object than a large one. [Answer] ### [That's No Moon](http://tvtropes.org/pmwiki/pmwiki.php/Main/ThatsNoMoon) Use Earth's moon. When earthlings first try to land on the Moon, lay out some fresh dust and wait for them to leave. The novelty of the Moon will die down. The Moon, while a constant companion, is still really far off. Earth would be none the wiser until they [started mining](http://www.space.com/28189-moon-mining-economic-feasibility.html). That won't happen until there is an efficient way to get resources back and forth from Earth. This probably won't happen until Earth is Type I. --- **Extra Credit** If the earthlings get to close to fast, here are some strategies the Type II civilization might employ: * Spread some doubt ([conspiracy theories](https://www.wikiwand.com/en/Moon_landing_conspiracy_theories)) to force the mainstream media/leading scientists to keep repeating "Yes, we've gone to the Moon". The general public will become disinterested more quickly this way. * [De-fund agencies](https://www.wikiwand.com/en/Budget_of_NASA) with intentions of returning to the Moon to prevent any awkward mishaps. [Answer] [3753 Cruithne](https://en.wikipedia.org/wiki/3753_Cruithne) is an asteroid about 5 kilometers in diameter with a solar orbital period of almost *exactly* 1 Earth year. It is about 12 million kilometers from Earth at closest approach, and is never in a position where Sol is directly between it and Earth. [Answer] The science-fiction author Arthur C Clarke had already proposed a suitable candidate for an artificial object that is an artificial construct. Namely, the Jovian moon Jupiter Five. This has a nearly circular orbit around the planet. Its albedo is bright enough to be consistent to its surface being polished metal. The diameter of Jupiter Five is thirty-five kilometres. [![enter image description here](https://i.stack.imgur.com/bWHMS.jpg)](https://i.stack.imgur.com/bWHMS.jpg) Clarke employed the concept in his short-story, appropriately titled, "Jupiter Five" where it is discovered that Jupiter Five was a spaceship that had brought members of what was called "Culture X" to the solar system, possibly, millions of years ago. Why go past the work of a master of the art. Jupiter Five is a suitable candidate to be a monitoring artefact installed in the solar system by Kardashev Type Two civilization. In all probability, this would be their base of monitoring vessels and surveillance systems to observe life and activity of the human species on planet Earth. Jupiter Five is an object well known to astronomers. EDIT: Thanks to kingdelion's comment about Jupiter Five being the Jovian moon Amalthea. Further information about [Amalthea](https://en.wikipedia.org/wiki/Amalthea_(moon)) can be found here. This suggests that Amalthea is less of a metallic spheroid, as in Clarke's story, but more of a pile of rubble and icy material. Still there is no requirement for Kardashev Type 2 civilizations to be neat builders. Generally what may have been a good idea in 1953 may not be so brilliant now in 2017. Orbiting piles of rubble could be still the perfect cover for galactic monitoring stations. [Answer] No major solar system body could realistically be said to be artificial. However, [Iapetus looks artificial](http://www.google.com/images?q=iapetus%20death%20star). It is a major body (you accept comets and asteroids but I'm setting the bar higher), has odd features that could be explained by an artificial origin and is not nearly as large as the planets and largest moons or dwarf planets, making construction easier. (Also it is the Death Star.) [Answer] One overlooked possibility is to hide your satellite right under our nose(s) - among human produced Earth satellites. While not considered "major" bodies, these fit the question as they are regularly tracked and catalogued by professional and amateur astronomers alike, and any unknown satellite would be automatically considered a secret military bird (perhaps belonging to the opponent from the Cold War era). You do not even need to hide the artificial signatures of the satellite (tough it is advisable to paint it with the same spectral characteristics as produced by Earthling paints). [Wikipedia has a category for reconnaissance satellites](https://en.wikipedia.org/wiki/Category:Reconnaissance_satellites), of course. Those that were declassified or those where the information leaked,anyway. [Answer] Deimos, moon of Mars? Its origin is somewhat unknown, it isn't too big and has been known for quite a while, 1870 or something. It's close to Earth so it can study us in relative detail. [Answer] In Clifford Simak's story "Construction Shack," humans arrive at Pluto and find it is hollow. They go in and find the blueprints for the Solar System! Apparently, whoever had the job of building the Solar System built Pluto first, as the base from which they would work. My father was a civil engineer with the New York State Department of Transportation. When they were constructing a new superhighway, they would park a mobile home on the site; this would serve as the office for the engineers, break room, etc. [Answer] Working up Wikipedia's [list of solar system bodies in size order](https://en.wikipedia.org/wiki/List_of_Solar_System_objects_by_size), S/2009 S 1 seems to be the smallest body that meets your criteria (it's a moon of Saturn), and therefore the most likely to be an alien artifact (it's only 300 metres across). If you want bodies that people have heard of, Icarus is a reasonably well-known asteroid and is only 700 metres across. [Answer] This is already in one of your answers, but Luna is, in my opinion, an excellent candidate for several reasons: 1) The placement and size of the moon is perfect for keeping the earth's axis from wobbling. This prevents, for example, half the planet from entering permanent day or night when the axis wobbles to face the sun. This has happened to Mars in the past and is theorized to be one of many reasons the red planet doesn't have large amounts of life. 2) It's large enough to house any number of highly technological constructs without risking their detection. 3) The capabilities of a Type II civilization are so far beyond what we are currently capable of that we don't even know if such a civilization would need to have actual monitoring equipment as we know it. For example, they may have forged a deep connection with the universe in order to "borrow" data storage and processing power from the universe itself, such that their thoughts don't necessarily have to happen within the confines of their own brains. This would render them effectively omniscient, so monitoring equipment would be beyond redundant. If this were the case, the only evidence of their interference with the earth might just be in the odd coincidences that resulted in life on Earth. 4) The moon represents an interesting candidate because one side always faces the earth, so any technological constructs could easily be hidden on the "dark" side of the moon under a small layer of dust without damaging broadcasting capabilities, and it could also serve as a plot device allowing governments to keep the discovery of such a facility a secret from the general public. Excellent fodder for the conspiracy theory crowd. 5) So much of our biology and culture is related to lunar cycles and changes that discovering that it is artificial or that it was placed there as some sort of extraterrestrial intervention would send shock waves throughout all human society. Gestational periods of human women, mathematical conventions for measuring angles and other geometric constructs, architecture both ancient and modern, and pretty much all life on earth reflects strongly the influence of our primary satellite. If you dig into it, some happy accidents of mathematics occurred because of the influence of the moon on human culture. If an artificial satellite created or at least influenced in some way by a type II civilization is a central plot point for you, I believe the moon would be an excellent choice because of how powerful such a revelation would be to the whole of mankind. [Answer] Let me give a different answer from the others. **Pluto** Why Pluto? Simply because it is by far the least explored of the major astronomical bodies, and the least likely to have had it's artificial status discovered. It's also surprisingly small by comparison with it's almost-brethren. Sure you can go with an obscure asteroid, but where's the drama in that? It's distance from Earth makes it's monitoring job harder, but that shouldn't be a problem for the kind of civilization we are talking about. Or you can go down the route of "The Sentinel", where the discovery of the artifact is the event that means Human civilization is ready to be contacted. [Answer] If by "realistically be artificial" you mean easiest to construct and place then the answer (which admittedly is a cop-out) is whatever the lightest object that meets your criteria for major solar system body is. The energy expenditure to place even a small asteroid into solar orbit from outside the solar system is going to dwarf any other design considerations. [Answer] If the real thing that would give you away would be heat production (of whatever technology you leave behind, plus power production), then maybe the best bet is one of the moons of Jupiter with interior oceans. There you have enough natural heating that you could possibly hide the heat of clever technology and perhaps even be able to use the natural heating to provide power. And the ice could act as radiation shielding for the more sensitive gear. Maybe an advanced enough civilization could use nanobots injected into the geysers as sensors and/or once and a while drill up and stick out a telescope (or whatever) to take a quick glance at Earth. [Answer] # A black hole. Impersonating a black hole would provide a drool-worthy level of secrecy; however there are several problems associated with it. ***Problem:*** Black holes bend light which requires stupid-levels of gravitational pull, likely making the ship itself an inhabitable pressure-cooker. * ***Unless:*** The civilization piloting the vessel has especially kick-ass refraction and/or reflection technology to emulate the phenomenon. * ***Or Unless:*** said vessel had *slightly-less-kick-ass-,-but-still-pretty-kick-ass* refraction/reflection tech, and only a *directed* illusion was required. + ***For example***: If the cloaked vessel was traveling towards a planet, it would have an easier time directing its illusion at the inhabitants of that planet than it would appearing as a black hole to the entire galaxy. ***Problem:*** A few issues: * **A.)** I'm being vague about the aforementioned *"kick-ass"* light-bending tech. * **B.)** Even in my "***Or Unless:***" example, the difficulty of maintaining such an illusion would scale with distance the from the target. * **C.)** Black holes do not simply pop into existence. If the target planet or vessel was pre-space-flight, there's a good chance they'd still pick up on a black hole appearing out of nowhere. + **A.) *Unless:*** I am being vague about potential optics-tech on purpose. Future tech b crazy B. Get creative! + **B.) *Unless:*** Yeah this would be an issue...Ideally a probe could be sent ahead of schedule to maintain the illusion from a fixed point relatively close to the target. + **C.) *Unless:*** Maybe they do?! Wouldn't it be a spectacle to witness a never-before seen cosmic-occurrence? **Assuming that the target is stationary & less technologically advanced,** they could be studying the illusionist's decoy right up to the point when a bunch of warships pop out behind it. ***Problem:*** Gravitational waves dude. * ***Unless:*** um...yeah. It's science fiction! Maybe people can project gravitational waves now? It's up to you. ]
[Question] [ We know that planets can have multiple moons, sometimes quite a few (like Jupiter). Assuming that a planet with several moons were habitable in the first place and has significant oceans (greater than 50% of the surface), what effect would multiple moons with independent orbits and revolution speeds have on tides? Would they tend to cancel each other out, amplify the effects, cause less-predictable tides, or what? If I want to cause one of those outcomes, what factors do I need to alter in my design (moon size, distance, orbit pattern, ?). This is for a story in a polytheistic society with competing moon gods ([starts here](https://medium.com/universe-factory/sisters-a718622d808f#.tvk562uff)). [Answer] **TLDR** You can model the effect of two moons by summing two sine waves. To do this plot each moon as a function of Time and manipulate the gravity of the moon by changing the amplitude and the orbital period by multiplying the time variable. A final plot showing the summation of the others gives the resulting forces on the tides. **Long Version** In reality calculating tides is VERY complicated, it depends on many factors involving river emptying into the sea, the terrain around the shore, currents, weather etc... However, we can come up with a rough approximation which will at least help us get a feel for how the tides would work. The first thing to establish is whether the moons would have to have the same orbital period (do they both take either same amount of time to orbit the planet?) the answer is no, Europa has an orbital period of 85 hours and Ganymede of 172 hours. This means each moon can be independent to each other. Next you need to determine whether both moon are on the orbital plane, I would suggest they are. After all the planets in the solar system orbit on the same plane and it keeps the maths easier. So you've got two moons of different masses orbiting at different periods. You can represent this very easily as a graph with two sine waves on it. The high tides on any given day are the cumulative force from the moons. For the sake of argument let's say moon A has a force of 10 and a period of 10 days, moon B has a force of 15 and a period of 15 days. You can plot this for time, now draw a third line which is moon A's force plus moon B's force. This is effectively your tide table. You'll notice that you have low tides and high tides as normal but every so often you have super high and super low tides! Next all you need to do is decide the maximum and minimum tide heights and scale the graph accordingly. Using this technique you not only get a feel for what the tides would look like but also can calculate down to the day when the high tides will be. In the example below there are two moons (Green and Red) on the graph, the net impact of these moons is shown in blue. As you can see one moon dominates the tides fairly dramatically (because it's significantly bigger) but the red moon has enough impact to warp the tides a little. I mocked this up with [FooPlot](http://fooplot.com/): ![Tide Example](https://i.stack.imgur.com/1o1aS.png) For sheer curiosity I've messed with the orbital period of the red moon — now you can see very dramatic impacts on the tide line (blue). It looks like tides with this lunar configuration have much longer low tides which suddenly rush in. ![Tide Example 2](https://i.stack.imgur.com/Mr1nf.png) To add a little more maths for those of us (including me) who haven't studied trigonometry in a while. When messing with waves there are three values you can adjust Frequency, Amplitude and Phase. These represent * How long it takes for the moon to orbit the planet * The strength (related to gravity) of the moon's effects on the tide * Synchronising the moons - slides the tides back and forward so you can line up double full moons and such. You can plot this like so: $$ \mathrm{TidalForce} = \mathrm{Amplitude} \times \sin((\mathrm{Frequency} \times T) + \mathrm{Phase}) $$ T in this case is the time from the start of the cycle, as you increase it you get the change in TidalForce. Phase manipulates T=0 and the Full Moon (using FooPlot at least is degrees so 180 is half a lunar cycle). [Answer] It would mean a more complicated modulation of the tides. On earth, we have a superposition of two cycles: An exactly 12 hour cycle of the sun, and a cycle deviating from that by the moon. The moon tides are dominant because the sun, although much more massive, is much farther away. Yet the effects are already within the same order of magnitude. What this results in is the pattern of spring tides and neap tides. Spring tides are tides where the sun tides and the moon tides are in phase, so they add up. Neap tides are when they are exactly opposite, so the sun tide partially cancels out the moon tide. Now with several moons, you'd add further oscillations in the mix, which — assuming the moons are all far enough away to have many-day cycles — would add to the pattern of spring tides and neap tides, which would make that pattern more complex (in the simplest case, you'd get a modulation if the spring/neap tide height created by the other moons). While the most likely orbit for a moon would be a equatorial (or close to equatorial) one, also other orbits are possible (although less likely). The other extreme would be a polar orbit; the tidal effect of that would be to have an exact half *siderial* day period (the siderial day is the time of one rotation; the solar day is slightly different because the movement of the planet over the sun). Such a polar moon would create maximal daily tides while above equator, but no daily change while above the pole; the cycle of that would be the orbit time of that moon. Note that the tides in the polar region, which are zero for an equatorial-orbit moon, would have an orbiting-time cycle with that moon (of course several such moons would again give a superposition of such cycles, resulting in polar spring and neap tides). Assuming that the equatorial plane of the planet isn't too much tilted to the ecliptic (that is, you've got days and nights), you'd got a yearly pattern of whether the daily ("equatorial") tides by that polar-orbit moon have spring- or neap tides due to the solar tidal contribution. Of course similar considerations would hold for the tidal superposition with equatorial moons. Note however that the earth's moon is extraordinarily large compared to the earth's size; most moons are much smaller and thus have a much lower effect on the tides. Also note that the moons cannot have arbitrary orbits, because if they come too close to each other, they'll disturb each other's orbit too much so that it won't remain stable. Also note that I've assumed approximately circular orbits; elliptic orbits would cause extra effects, because the tides would be larger when the moon is closer. Of course all those possibilities would also have effects being seen in the moon phases (and the moon's position). Indeed, predicting the tides would still be possible by just looking at the moon phases. A polar-orbit moon would have particularly interesting moon phases where there would be a seasonal change between normal moon phases (when the sun is in the moon's orbital plane; the time when this moon would have its solar spring tide) and a continuous half-moon (when the sun's direction is perpendicular to the moon's orbital plane, the time where this moon would have its solar neap tide). [Answer] Tides are fairly predictable even in the case of multiple bodies. Assuming that all of the moons orbit the planet in times that take longer than a day, the tides will have a period of 1/2 of a day (much like our 12 hour tide cycle on earth). Every gravitational body generates a tide on the line connecting the center of the two bodies. The bulge is on the near side and the far side. If you add a second moon, this would again make a tidal bulge on its respective center-connecting line. These two tidal effects would superimpose on top of each other. So when the two moons are in phase (both are directly overhead at the same time of night), their tidal effects would add. When the moons are out of phase (one is just cresting the horizon when the other is overhead) the effects would partially cancel. The strength of each effect depends on the mass and distance to the moon. Adding more moons would add another superposition. Of course this is a first order approximation. The shapes of the bodies of water, landmasses, depths, and frequencies of orbit all have higher order effects, but depending on your purpose, these effects may be negligible. [Answer] Our tide would be affected and so would be light distribution of Earth. [What if the Earth had Two Moons?](http://www.universetoday.com/92148/what-if-the-earth-had-two-moons/) This article appears to be very similiar to what you are talking about. But this is saying what would happen if a another moon came to Earth. > > Humans would have to adapt to the challenges of this two-mooned Earth. > The higher tides created by Luna would make shoreline living almost > impossible — the difference between high and low tides would be > measured in thousands of feet. > > > The combined light from the Moon and Luna would make for much brighter > nights, and their different orbital periods will mean the Earth would > have fewer fully dark nights. > > > Eventually, the Moon and Luna would collide; like the Moon is now, > both moons would be receding from Earth. Their eventual collision > would send debris raining through Earth’s atmosphere and lead to > another mass extinction. > > > So from that we can say that multiple moons would enhance the affect on the tides of Earth without really cancelling out anything. So from that I would say that if many moons were next to one planet the affect would be minimum as they would be used to it. The only extra thing would be that maybe the life on their planet would look different due to extra gravitational pull exerted by many moons. [physicforums](http://www.physicsforums.com/showthread.php?t=357525) <http://www.thecbg.org/index.php?topic=34731.10;wap2> <http://www.madsci.org/posts/archives/1999-02/917414217.Es.r.html> <https://answers.yahoo.com/question/index?qid=20110928103836AAVxPY7> [Answer] > > Would they tend to cancel each other out, amplify the effects, cause less-predictable tides, or what? > > > All of the above! Depending on their relative position and distance (e.g., apogee or perigee) and mass they could either cancel each other out or amplify the effects. Calculations may be regular and predictable, but also more complex, leading to an illusion of being less predictable. Something worth keeping in mind is that earth's moon is quite large compared to others in the solar system, relative to the size of the planet that it orbits. Eclipses? Get used to them, there will be plenty. Calculating the month? Ummm.. Which moon was that again? Night sky? Each moon adds brightness. etc. Also check out Skyrealms of Jorune :) [Answer] I love the idea of competing moon gods! The people might not grasp the relationship between the moons and tides but might if the cycle was apparent. On an island in a global ocean with no girdling contenents to block the tide and keep the water in separate sloshing bowls, it would work as seen on the plots above and except for the part about also working on the backside it would be seen that the moon raises tides and they all pull individually. Now in a large comma-shaped landmass in the southern hemisphere, the native peoples see a chaotic tide with no obvious relation. The water moves around local areas in gyres, and they are *pumped* by the tide like a kid's swing is pumped by his legs. It will not work so well if the pumping is not in a clean rythem. The gyre can do crazy things and even reverse direction. The north sea-people come to the south and have an understanding of tides and with skills like our Polynesians they figure out the existence of gyres. What will the difference in phenomena do to their beleif system and what might they try and teach the southerners? Add to that different *stars* and astrology interpretations can have a lot of creative input. [Answer] There are a couple of issues here: A: Multiple moons of significant size compared to the planet are rare. There are weird resonances at work. I wasted a winter day playing with online orbital simulators and was never able to make a system one moon had a mass of 1/80 the primary, and the second moon a mass of 1/640 the primary and get a situation where it was stable for more than a few tens of orbits. Usually the small moon was ejected or crashed into the planet. B: Tidal forces vary as the inverse cube of the distance. Move a moon to half the distance,get 8 times the force. C: Gravitational force for a given density varies as the cube of the diameter. D: B and C together mean that the same visual diameter moon made of the same stuff gives the same size tides. E: Mid ocean tides can be calculated by mere mortals. At coasts you have resonances, and delays. Lot of tide tables are (or were) empirical from records. F: Earth's moon is 1/2 degree across angular diameter. Lots of pics show moons that are huge. 10-20 degrees across. Either they have to have incredibly low density, or your planet and moon are tidally locked to each other. Even moving our moon to Roche's limit -- about 40,000 km would give it an angular diameter of 4 degrees and it would raise tides hundreds of meters high. ]
[Question] [ Could a Dwarven society as described by Tolkien mythology actually work? Dwarves for the purposes of this question are short, stout, bearded men and women who live primarily underground. They have a medieval level of technology although perhaps some advanced metallurgy techniques. They mine deep into mountains, creating vast networks of chambers and halls where they dwell. There seem to me to be several unaddressed problems with how a Dwarven society would work. **Mining:** We have a hard time digging into the earth safely even with modern technology. Could Dwarves actually create safe underground dwellings at a medieval tech level and without the use of magic? How deeply could such a society safely dig without the risk of poisonous gasses, cave-ins, or Balrogs doing them in? Are the massive subterranean structures we see in Middle-Earth possible? **Air.** Mammals exhale carbon dioxide that will inhibit their ability to get oxygen into their blood if it reaches too high a level. As a tunnel goes deeper into the Earth and further from the surface air supply the Dwarves will eventually suffocate. How can they cope with this and keep massive underground networks such as the Mines of Moria habitable? Today we use fans to generate circulating air networks. Is there any way for the Dwarves to replicate such tools with medieval technology? **Food.** Let us say for the purposes of this question that Dwarves do not farm or hunt above ground. What could they eat? Are there any ways to grow food underground? They need a renewable, reliable food supply for a large population. Trade would be one option, but would require the Dwarves to live in close proximity to surface dwellers and would make the Dwarves wholly dependent on their trade partners. None of the answers need refer to Middle-Earth in particular. I only mention it because it’s something that most people are familiar with and has inspired most of the Dwarves we see in modern fantasy. I’m interested in non-magical, non-fantasy answers. I essentially want to know if a hairy, burly group of men and women could live underground on earth. No other problems come to mind, but I’m sure there are others. If anyone else has concerns about the feasibility of a Tolkien Dwarven society please bring them up as well. [Answer] Some things need to be addressed here. Can the structures be made? When does a mine get too hot? What about asphyxiation? What about food? It should be noted that many of the issues here can be solved or compounded by local factors, so this answer applies in general cases, not specifics. Where the dwarves decide to mine, what rock they are mining, and other factors can make a place viable or not. # The Structures Obviously, these dwarves are masters of [rock-cut architecture](http://en.wikipedia.org/wiki/Rock-cut_architecture). There are [examples](http://en.wikipedia.org/wiki/Underground_city), mostly in India, of cities, towns, and temples which were carved from stone. It is very possible, as we humans did it! However, I doubt much of these go as deep as someone may think the Mines of Moria go. In any case, the structures themselves can happen with Middle Age tools and techniques. The limiting factors are likely how hot it got and asphyxiation in your dwarf-town. In fact, it may be easier to make Gothic Architecture inside of mountains because you start at the ceiling and dig down! # Underground Temperatures The TauTona and Mponeng Mines are really deep; about [3.5 km](http://en.wikipedia.org/wiki/TauTona_Mine) and [4 km](http://en.wikipedia.org/wiki/Mponeng) below the surface, respectively. They report temperatures of 55-60 degrees C and 66 degrees C. Way too hot for most human-like biologies to function. Many [sources](http://www.cliffsnotes.com/sciences/geology/inside-the-earth/geothermal-gradients) claim that the geothermal gradient is about 25 degrees C per km, so unless your dwarves have some awesome ability to cool themselves, you would not be going that deep. Humans can live at about 21 C *quite* comfortably, but ~38 C can cause problems. At that temperature, you run a huge risk of heat exhaustion and heat stroke, as the rock and air around you is as warm as you are. To put this in perspective, 1 km may actually be deeper than you realize, as it isn't a long distance to walk, but it is a long distance to dig or fall. (The [Grand Canyon](http://en.wikipedia.org/wiki/Grand_Canyon) can get up to 1.8 km deep!) Then again, if the surface is freezing, then getting 25 C warmer would be *really* nice. # Air This is a tricky one. Living on a mountain, you could use winds to make bellows and pipes to move air as needed down pipes or tunnels. Bellows are so old we are not sure who made them. There are even words for them in [Old Norse](http://en.wikipedia.org/wiki/Bellows)! They were around in the Middle Ages of Europe. This is very energy-intensive, though, so it is not the best solution. What about the open spaces and halls you seen in the movies? ![Erebor by Caoranach on DeviantArt](https://i.stack.imgur.com/c9v3E.jpg) This may actually help, because the large body of air (with internal convection) can give a dwarf population enough air to last them longer than if it was a narrow hall. You would just need some well-placed windows up high or on opposite sides of your mountain to allow fresh air in. Additionally, we know of many caves that are [really big](http://en.wikipedia.org/wiki/Cave#Records_and_superlatives)! If these dwarves were especially good with fluid dynamics, they could create an air tunnel system which takes prevailing winds and [temperature gradients](https://en.wikipedia.org/wiki/Displacement_ventilation) to funnel fresh air through their tunnels. This is tricky, and can be difficult to do. You also need to worry about [damps](http://en.wikipedia.org/wiki/Damp_(mining)). Those are pockets of dangerous air. The technology used to manage them range from very complicated to hanging sheets to guide air. Obviously, dwarves can hang sheets; they just need to guide the air to a place where it can safely diffuse. Once again, the giant halls and open spaces would be helpful. # Food Cave Ecosystems are difficult. Here is a list of [troglobites](http://en.wikipedia.org/wiki/List_of_troglobites); creatures who *exclusively* live in caves. There is not much there that is very nutritious, nor is it especially abundant. The [US National Park Service](http://www.nps.gov/grba/naturescience/cave-life.htm) claims that caves mostly rely on resources coming in from the outside. That is prime real estate for decomposers, like mushrooms and insects! You can have an ecosystem which does not rely on sunlight at all, as the oceanic thermal vents have shown us. Similarly, you can have [chemoautotrophic bacteria](http://en.wikipedia.org/wiki/Chemotroph) which could, *in theory*, form the foundation of a dwarf-sustaining ecosystem. The downside, however, is that cave-life seems to not get especially large. If you look at the list of troglobites, you will see a lack of mammals. There are people who want to grow plants underground, such as the people of [growing underground](http://growing-underground.com/). However, you would need a source a light, and LEDs / full spectrum lighting is likely beyond our dwarves. You could try a series of mirrors, but mirrors of that size and quality would likely be too hard for dwarves to make. (They may have been able to use [tin or other metals](http://en.wikipedia.org/wiki/Mirror#History), but its unlikely.) Given these lists of troglobites, and whatever finds its way into caves, it would be safe to assume that dwarves have no scruples about eating fungi, fish, or insects. Those living strictly underground would rely on eating those. [Answer] # Mining There are a number of species on earth, including insects, mammals, birds, and reptiles that create massive structures underground, so it's not inconceivable that such burrowing could be done with medieval technology. In fact, we were able to create [fairly incredible mines in medieval times](http://en.wikipedia.org/wiki/Mining_and_metallurgy_in_medieval_Europe). Perhaps early dwarves were burrowing humans, and they subsequently got better and better about reinforcing their structures with wood and then stone. Since they were "naturally" burrowers, they had deep knowledge about different types of the land, and the earth and stone underneath it. This let them select ideal locations for mines and burrows. Poisonous gases, cave ins, etc. would be real problems, and conceivably, thousands (if not millions) of dwarfs would have died because of this. However, over time, they got better and better about building massive structures underground. Imagine, for instance, if the structural technology of the pyramids were leveraged to support massive underground chambers. By the "Roman Era", dwarves would have significantly improved on this technology. # Air Ants are capable of building incredible underground chambers that properly circulate and ventilate air. Dwarves could also develop this technology. It would rely on judicious use of air pressure differences and/or wind to help vent carbon dioxide. Also, dwarves may also evolve to be more tolerant of CO2 or other gasses, which would allow them to remain in poorly ventilated mines longer. More than just air, however, water and flooding would be a big problem. However, technology for moving and pumping water was well established by medieval times, so this would not likely pose too big a problem for our dwarves. # Food Dwarves would likely be dependent on above-ground food. However, there are a couple possibilities. One option would be to raise animals underground, and to feed them with plants like grasses or lichen that could grow in the meager light provided by torches (or perhaps skylights). This would require large areas to raise these animals and enough greenery to feed them. A slightly more ridiculous option would be to cultivate certain kinds of root vegetable that would grow deep into the earth. Then, the dwarves could simply cut off the roots (or pick the potatoes, peanuts, etc.) from underneath, and the plant would then regrow those. It would likely require at least a few dwarves to properly protect and maintain the crops above ground, but would eliminate the need to transport the foodstuffs from the surface. [Answer] ## Mining Such vast underground structures occur naturally and as others have noted in areas of suitable rock people actually have built and used large underground complexes. The real question is why the **Dwarves** would stay underground instead of living above ground in areas of harder rock. It would help if we assumed some magic that gives benefits either to or from living underground. ## Air A properly planned cave system would have a natural circulation. It would be reasonable to presume the **Dwarves** can create such structures. This is because to people living underground the differences in circulation and air quality would be something they'd be constantly aware of. They'd not only be sensitive to bad air quality, they'd easily notice what changes would make a positive (or negative) difference, and they **would** talk about it and pass what they learned to the next generation. In fact, I think the **Dwarves** would rely on the air currents and quality for navigating their cave complexes. And be able to **scent** minerals? That might explain being exclusively miners. And not being bothered by the dark. In practical terms, they'd use natural convection in warmer parts to draw air from outside through the caves. The "warmer parts" would include deep parts with higher temperature, any forges or cooking fires the **dwarves** would have, and small outside towers on southern faces of mountains where sun would heat the rock and create an air current drawing air out. Intake would be through large shadowed caves. You would still want some biological adaptation to operating with lower oxygen. Not only would that help with dealing low oxygen areas, it would have other benefits. Your homes would be very uncomfortable for surface dwellers to invade, even before you close few shutters to cut off air circulation in the attacked area. In underground fighting people with lower oxygen needs would have a real edge. Lower oxygen levels would also reduce the risk of gas explosions and if you could also hold your breath longer it might help with toxic gasses as well. ## Food It is generally presumed the **Dwarves** get most of their food from above ground either from secluded mountain terraces accessible only from air or underground or in trade with surface dwellers. Even **Dwarves** need some excuse to forge new objects, so trading the old for food would be natural. And food is fairly cheap in comparison to gold and gems. So the **dwarves** would probably rely on surface food and lots of storage. Mountain gardens would be rather fertile due to large amount of compost available. And you really want some place to put that compost... Some food could be harvested from underground streams that came in from the surface. In addition to fish and other directly edible things almost anything organic could be used for mushroom farming. Bats could be domesticated. Same with other species that hunt on the surface but live in the caves. Caves have much more stable temperature than the surface. The **dwarves** might be adapted to this and thus waste less energy controlling their body temperature. They might also have lower metabolism in general. This would reduce the need for food and increase life span. The ultimate solution would be a food source that relies on chemosynthesis. The **Dwarves** themselves might be able use low concentration methane in the air for energy. This would not only make living underground more practical, it might explain **why** they live underground in the first place. Another suitable gas is carbon monoxide, which you can easily create from coal. Since both these gasses are quite dangerous having a natural ability to consume them would not only free you from surface food, it would make living underground much safer. And if you could breathe air with carbon monoxide in it and had ready systems for creating carbon monoxide already in operation, invasions by surface dwellers would be a non-issue. [Answer] As far as food goes, is it significantly harder for dwarves living underground to obtain food from the surface than it is for an urbanite to obtain it from the surrounding countryside? Is it harder to provision Moria than Minas Tirith, for instance? This is very nicely expressed by Terry Pratchett in *Night Watch*: > > In a few hours the shops out there were expecting deliveries, and they weren't going to arrive. ... Every day, maybe a hundred cows died for Ankh-Morpork. So did a flock of sheep and a herd of pigs and the gods alone knew how many ducks, chickens and geese. Flour? He’d heard it was eighty tons, and about the same amount of potatoes and maybe twenty tons of herring. ... Every day, forty thousand eggs were laid for the city. Every day, hundreds, thousands of carts and boats and barges converged on the city with fish and honey and oysters and olives and eels and lobsters. And then think of the horses dragging this stuff, and the windmills ... and the wool coming in, too, every day, the cloth, the tobacco, the spices, the ore, the timber, the cheese, the coal, the fat, the tallow, the hay *every damn day*. ... Against the dark screen of night, Vimes had a vision of Ankh-Morpork. It wasn’t a city, it was a process, a weight on the world that distorted the land for hundreds of miles around. People who’d never see it in their whole life nevertheless spent their life working for it. Thousands and thousands of green acres were part of it, forests were part of it. It drew in and consumed ... > > > ... and gave back the dung from its pens and the soot from its chimneys, and steel, and saucepans, and all the tools by which its food was made. And also clothes, and fashions and ideas and interesting vices, songs and knowledge and something which, if looked at in the right light, was called civilization. That’s what civilization meant. It meant the city. > > > [Answer] See for example: [Wikipedia](http://en.wikipedia.org/wiki/Derinkuyu_underground_city) and [Goreme](http://www.goreme.com/kaymakli-underground-city.php) sites. I recall being told on a visit to one of the Cappadocian sites [Kaymaklı and Derinkuyu underground cities](http://www.metiscappadociatours.com/cappadocia-places-to-visit.php) that it was originally 10 stories deep. A vertical ventilation shaft somehow ensured air circulation. Building within a mountain chain rather than down into a volcanic plain might provide a big improvement on the possible depth than can be ventilated. This is called the Venturi effect: the vertical shaft extends into areas with higher air flow at lower pressure, causing a vacuum at bottom of shaft. However, a mountain chain would also have much harder rock than Cappadocia with consequent effect on mining, to the extent of being on the face of it quite impractical. To be quite honest, when I visited there I was reminded more of the Goblin Caves in the Hobbit than the Mines of Moria. [With regard to the engineering possibility, you could argue that Peter Jackson's Moria was more ambitious than necessarily implied by the Tolkien text.] Note that these cave dwellers had their agriculture on the surface. I do not recall anything indicating that the dwarves produced food underground. Certainly they are supposed to have traded manufactures for food. I haven't looked up the detailed timeline, but Moria was supposed to be at its height when there was a thriving economy in Eregion. So, in summary, the air and food could probably be solved non-magically, but the mining of mountain rock less so. [Answer] # Farming underground You can [grow mushrooms underground pretty easily](http://gizmodo.com/why-a-small-pennsylvania-town-is-the-mushroom-capital-o-1507494984). But you have to bring the substrate (dung, soil, tree bark) they grown on from the surface. As you have constant temperature year round underground, this will be great to have food for the winter. You might even be able to feed some rodents with it to put some fresh meat on the table. # Fishing underground If there's a river with an underground part, you might be able to catch some fish that are passing through or [cave fish living off what is brought by the water from the sunny part](http://en.wikipedia.org/wiki/Amblyopsidae) of the river. Some Olms and Salamanders also live in caves with water. But there always has to be water coming in from the outside bringing the nutrients. You might be able to build a canal that diverts a regular river into your underground mine. Then you can leisurely eat anything it brings with it. Fish farms would be possible too, but you need to bring the fish food from somewhere else. [Answer] Creating a chimney effect in a mine under a mountain would provide adequate ventilation, and the medieval world (dwarf world equivalent) knew windmills. With modern power and light would be much easier, and mining technology now means we can let the machine do it, and with renewable energy. A bit surprising that there are not more fantasy underground cities in the mountains, now. May be a gap in the market. See fantasy underground city in the Blue Mountains (west of Sydney Australia) meetup group. [Answer] I worked on this problem a bit. Understand this was in a mythos in which pools of lava would be safe to stand reasonably near for a short time, so a few resources are available that should not be. There is this thing in the ocean called a tube worm that harbors bacteria that live off the heat exchanges between deep thermal vents and the ocean. Here we have not such a good cold sink but a really good heat source, so it's going to be hotter. I posited the same kind of thing could live here. Its biologic processes would drive soil breakdown and nutrient release leading to (ultimately) lava-drive mushroom growth. Of course recycling waste is a must. Guess what mushrooms like anyway. To deal with the contamination I further posited that dwarves brewed all the mushrooms into beer. Absurd? Well, no more than whatever allows standing pools of lava in caves to be safe to approach. Oh, and when they go to industrialize, guess where the power will be coming from? [Answer] I'm not an expert on these things but here are some thoughts I have gathered together: **Mining:** Dwarfs are known to be very skilled at mining and mining technology. On the other hand dwarfs are also know to be very self-centered and not exactly the friendliest folks towards others (as seen in all of Tolkien's works). This begs the question - how good are dwarfs at mining really? Because dwarfs are so fond of digging precious stones and metals from the earth I would guess that they would also fiercely guard their mining techniques and technologies so that no one else does it thus creating a monopoly over the trade with such items in Middle Earth. In Lord of The Rings we saw that Saruman was able to produce an explosive substance, which was later used to blow up part of the wall of Helm's Deep, but who says that he didn't steal this from someone else (the dwarfs for example?) using his palantir (the stone which allows you to see far, far from where you are including breaking the boundaries of space and time). **Note:** See the end of the post --- **Air**: There are of course limitations as to how deep one can dig however in terms of mining and air quality there are ways to provide fresh air at a certain depth using extensive ventilation system by creating drafts which 1)take oxygen from above the ground and 2)remove carbon dioxide from underground. That said air quality does degrade the deeper you go however you also have to consider the ability to adapt to certain conditions. Take the people who live up high in the Himalayas. The higher you go the less oxygen there is in the air. However people there have lived in such conditions for hundreds (or more) of years which lead to their anatomy adapting to the extreme conditions. Of course high levels of carbon dioxide are deadly but since dwarfs live in such condition my guess would be that their anatomy is adapted to **produce less carbon dioxide** and **consume less oxygen** plus **better ability to get oxygen from air with less oxygen**. This would allow dwarfs to survive at a much deeper level compared to other human-like creatures. Last but not least the size of all the shafts and halls do provide bigger pockets of air thus allowing better distribution of carbon dioxide. --- **Food:** While dwarfs are known for their mining and metallurgic skills in terms of farming and breeding stock they lack a lot. However just like in real life one can use trade to export metals, jewelery, precious stones etc. and import food and beverage instead (similar to what Japan does in terms of importing minerals, metals and fuel due to the very limited resources it has). In addition to that there are a lot of mushrooms and other plants that grow in complete darkness and also with enough artificial light, soil and water one can also create somewhat efficient farms underground. Plants also like having carbon dioxide around them (in modern terms I believe this is the so called carbon farming where carbon dioxide is additionally added to the air which the plants breath to accelerate their growth and efficiency) which would partially take care of the excessive build up of carbon dioxide underground. On the other hand plants also produce carbon dioxide on their own which will add to the already rich on carbon dioxide environment. It's a tricky situation with this one. Also I don't recall ever reading or seeing underground farms in any of Tolkien's works so my guess would be using trade as the only way of providing food and drinks to a dwarf society. Animals, who normally live above ground level, can also be moved underground though due to the lack of natural light such animals would be more fragile, probably blind (or at least with a far inferior vision capabilities compared to their representatives who live a normal live under the sun and in open spaces) and also this would be yet another source of carbon dioxide. --- If we go away from Tolkien's universe there are many universes where dwarfs are even more advanced especially in the usage of explosives and steam (in addition to possible alliances with the gnomes) which tends to go towards a more steampunkish theme. This allows creating more advanced machinery which will allows digging deeper, creating a more suitable habitat for a dwarven society etc. etc. [Answer] I have an idea: what if you made some sort of plant-like organism that evolved specifically to absorb thermal energy from underground thermal vents? This would be a good way to solve the whole “getting food underground” problem. They could even use some of those “thermal plants” to feed livestock. [Answer] True underground dwarves would need a source of energy to replace sunlight, and a way to convert it into food. A silicon based life-form like a troll might be able to eat coal directly, but dwarves are mammals. Even trolls would eat their way through a coal deposit in a few generations. I think this would be impossible with the usual iron-age fantasy technology. They could burn coal to power electric lights, and use that to farm but like the trolls, they'd run out before long because they'd would need to use it far faster than we do. Geothermal energy won't run out for billions of years, so they could use that to power the lights for their farm. Or a rich uranium deposit forming a natural nuclear fission reactor. They'd have to develop good drills, pumps, turbines, generators and electric lights, but being tied to underground power would explain why they've not used their relatively advanced technology to out-compete the surface dwellers. If you can solve the food problem, everything else is easy in comparison. ]
[Question] [ **Disclaimer:** This question uses some liberal wording to get key ideas across. It's not meant to be academically rigorous, so please try to focus on the ideas and not the exact definitions of the terms used. If you need clarification on something or have suggestions to make the wording clearer, I'll be happy to do so or add them. **Executive Summary:** The goal of this question is to explore whether or not space-faring species would have many "humanoid" characteristics. Here are some key terms used in the question with explanations of what they mean and how they fit into the goal: 1. **Intelligent life** - Life forms which have developed a [higher degree of social complexity](http://www.wikiwand.com/en/Evolution_of_human_intelligence#/Models) and demonstrated the potential to learn. For example, humans, dogs, birds and dolphins. **Proposed species must meet this criterion, or you must provide a plausible explanation for why it is not required.** 2. **Apex species** - A species which has dominated its biosphere and kept competition to a minimum or has a reasonable means of existing beside another dominant species. This typically includes, but is not limited to, "apex *predators*". For example, humans, tigers and orcas. **Intelligence is a prerequisite unless you can plausibly explain why it is not required.** 3. **Space-faring race** - The ultimate goal of this question. A species which *has the time and ability* to construct methods for achieving space flight. Keep in mind a harsh environment would significantly impact their chances of surviving as a species long enough to do this. For clarity, things like insects are not a good candidate for this unless you can **explain how they would achieve the intelligence prerequisite**. 4. **Humanoid** - Physically resembling a human pattern with two legs, two arms, a head containing sensory organs and possibly communication capability, etc. There are plenty of theories on what intelligent life would look like on other worlds. Sci-fi creators go to great lengths to come up with aliens who are truly alien to us. But would an intelligent space-faring race be anything other than generally "humanoid"? Would the universe have a reason to develop space-faring species other than [rubber forehead aliens](http://tvtropes.org/pmwiki/pmwiki.php/Main/RubberForeheadAliens)? Consider the following (keeping in mind these are *general descriptions* and not strict definitions), and remember that evolution succeeds only when it is more efficient than the base: * Without fine manipulators, we would not be able to use tools, and there's no sensible reason to develop tentacles on land. So, this only leaves hand-like clusters of extremities. * There's no conceivable need for more than two hands that wouldn't be outweighed by the inefficiency of having to supply them with energy. * Being bipedal gives us a combination of balance, fast/slow modes of travel, excellent ability to overcome obstacles and chase prey or escape predators. * Having more than two legs would imply a lack of hands due to efficiency constraints (how many intelligent creatures have you seen with four legs and two arms?) * A head containing the most critical sensory organs makes sense. Anything we've ever designed that's supposed to have good visibility is tall with all its sensor ability at the top (think air traffic control towers, lookout posts, etc). * Having the primary method of vocalization in the head also makes sense because the higher up it is, the better it will be at projecting sound (assuming sound is the main method of communication, thank for pointing that out @TimB). * Concentrating functions like eating/breathing/talking into one system is very efficient (again, virtually every organism we know of does this - certainly every dominant organism anyways). Sure we can design all kinds of crazy adaptations to deal with environmental threats but do we have any reason at all to believe they would happen in reality (and evolve/survive to the point where they become space-faring species) beyond just "we want more flavor"? The most variation I can conceive of would be skin composition, to allow for living in various elements. But I think ultimately the dominant species would evolve away from having seriously-protective skin features. After all, they would spend tens or hundreds of thousands of years using their intelligence to craft environmental stabilizers like clothing and shelter, so having fur or even just tough skin would have become unnecessary long ago. We ultimately have had the chance to hone our intelligence to the point of making technological advances thanks to the fact that *life on earth isn't that rough*. If we were in a world full of constant threats or changing environments, chances are our evolutionary path would have taken us in the direction of physical survival instead of intelligent expansion (e.g., armor plating instead of a bigger brain). **TL;DR**: Is there any truly convincing argument for an intelligent, space-faring species to *not* develop with very similar characteristics to humans? Or as put more appropriately by @Taemyr: "Do we have any reason to assume that any particular intelligent alien would have a markedly different body plan than homo sapiens?" **Edit:** To be clear, I'm asking for fully-explained logic showing why a significantly different "style" of organism would end up not only being the dominant species on its planet but be successful enough to develop space-faring technology. Please focus answers on *plausible examples* based as much in science as possible. [Answer] It's important to understand that our "dominance" as it were, is entirely a fluke. There's no intent or drive to make something intelligent; and there's little about our general design that made it even likely. We just had a series of flukes. Our ancestors happened to be members of the groups which: * on dividing as single-celled organisms, stayed together in a colony, rather than dispersing. Eventually, individual cells became specialized, creating multi-cellular life. * laid down support structures on the inside (vertebrates) rather than the outside (arthropods). This doomed us to never dominating the planet, as the creatures with exoskeletons have always ruled the world, and likely always will, vastly outnumbering us, out-weighing us in terms of biomass, living in a far wider range of environments, outdoing us in just about every possible interpretation of survival, and infesting and living off us. * controlled their buoyancy by gulping air into their digestive tract, which eventually branched into fish with swim bladders and lungfish: we came from the lungfish. * were tetrapods, with four fins, laying the framework for their descendants the quadrupeds (all reptiles, amphibians, birds and mammals). * lived in seasonally flooded mangrove swamps or tidal basins, so were regularly exposed to air, developed fins that could grasp onto roots and stalks, and eventually began to spend the majority of time on land... though naturally we'd been beaten to it by millions of years by the arthropods: insects, crabs, etc. [![tetrapod evolution](https://i.stack.imgur.com/jMaMn.jpg)](https://i.stack.imgur.com/jMaMn.jpg) * invested in internal maintenance of body heat, which served us well when the skies went dark and the ones who'd chosen external thermoregulation died off. * climbed (brachiated) in trees to became monkeys, this brachiation providing necessary preadaptations to bipedalism and tool-holding. * had their tails atrophy away (why? We don't know!) to become the apes, resulting in bipedalism rather than kangaroo-style tripedalism. * lived on water-based prey, likely in mangrove swamps (which may also have lost us our fur covering), so had ample supplies of essential fatty acids for surplus brain growth. * were large-brained generalists: omnivorous, adventurous, opportunistic and inquisitive. This led us to start using tools. * were socially gregarious enough to share the abilities that tools gave. * had a descended larynx, such that complex speech could be developed, and thence storytelling and passing on of knowledge, eventually leading to writing. It's language -- and more importantly, the preservation of knowledge that it permitted -- which meant agriculture became a thing, and later, sharing of tool designs, mathematics and science led to the industrial revolution. We could have accomplished all this in ANY body form that had language and a large enough brain to transfer concepts -- none of the rest mattered. And it's a good thing that form did NOT matter, as the form we have, with its vast flaws, is a result of all these accidents. With only two legs, we are essentially crippled if we lose one, compared to most quadrupeds who can easily adapt. We get backaches, hernias, obesity, and varicose veins, all because of this darn bipedal stance that the mammalian quadrupedal frame was not formed to take -- we've adapted to it, but it's an obvious bodge job, requiring a reworking of all our insides that makes childbirth almost nightmarish and our children incapable of escaping on foot for years. None of this was required. It was all just a fluke of chance, unlikely to be repeated anywhere else. But language, and complex, curious brains? Very likely to eventually be repeated on any planet with life. Whether that inevitably leads to tool use, and whether tool use inevitably leads to space travel, I cannot say... but to me, intelligence and curiosity beget desire to accomplish things; a desire to accomplish things in an intelligent being, becomes a seeking for methods to accomplish that end; and so tool use feels inevitable, and we see it in most species that we consider even slightly intelligent. In human cultures at least, being able to see the sky also seems to inevitably lead to observing it, and curiosity leads to wanting to explore a thing more closely. --- Edit: the above answer focused on the core assumption that our form was inevitable. But I guess I might as well address the other assumptions, though others have already done this well. > > uses some liberal wording ... not meant to be academically rigorous > > > Understood: I shall avoid definitional nitpicks. > > Apex species - [...] For example, humans, tigers and orcas. Intelligence is a prerequisite unless you can plausibly explain why it is not required. > > > Wouldn't a plausible explanation be "the only one in your list of 'humans, tigers and orcas' which even exhibits tool use is the anthropocentric one"? The tool-using species that we are aware of (see list below) tend to be generalists and scavengers, not apex predators. > > Without fine manipulators we would not be able to use tools, > > > Tool use has been observed in the following animals: * Primates (humans, chimps, bonobos, orangutans, capuchins, baboons, mandrills, macaques; earliest known evidence of tool use in protohumans 3.39 million years ago) * Other mammals (bears, elephants, otters, dolphins, kangaroos) * Cephalopods * Reptiles (alligators, crocodiles) * Insects (ants, wasps) * Fish (wrasses, stingrays, damselfish, cichlids, archerfish) * Birds (finches, corvids, warblers, parrots, vultures, nuthatches, gulls, owls, and herons). Not all of these use hands or "fine manipulators". In fact, they can be said to fall into these categories: * Hands/feet: primates, bears, otters, kangaroos, some insects. * Beaks/mouths/mandibles: dolphins, reptiles, insects, fish, birds, ants. * Limbs without fine manipulators: insects, fish. * Tentacles: primates, elephants, cephalopods. > > and there's no sensible reason to develop tentacles on land so that only leaves hand-like clusters of extremities. > > > I admit I bent the term "tentacle" above, to include all prehensile (="grasping") things other than hands. The list of prehensile things includes (non-exhaustive list): * Hands/feet: just about anything that climbs trees, primates, bears, otters, kangaroos. * Tails: reptiles (lizards, geckos, chameleons, skink), seahorses, various fossil animals. * Tongues: giraffes. * Noses: elephants, tapirs. * Penises: tapirs, dolphins, maybe elephants? * Lips: manatee, sturgeon, orangutan, horses, rhinos Given this range of fleshy grasping items, most of which are on land, it seems strange to assert that tentacle-style grasping on land is not something that would be selected for. > > There's no conceivable need for more than two hands that wouldn't be outweighed by the inefficiency of having to supply them with energy. > > > The Orangutan would beg to differ. In fact, the following creatures have more than two separately-controllable prehensile appendages, tailed ones often having five, and some having over ten: * mammals (monkeys, opossum, anteater, binturong, kinkajou, harvest mouse, porcupines, tree pangolin, rat, potoroidae, monito del monde) * reptiles (kink, chameleon, snakes, gecko, alligator-lizards) * amphibians (salamanders) * cephalopods (octopi, squid, cuttlefish, nautiluses) * Also just about anything other than birds which regularly climbs trees. > > Being bipedal gives us a combination of balance, fast/slow modes of travel, excellent ability to overcome obstacles and chase prey or escape predators. > > > Being bipedal also gives us hernias, instability, inability to run from predators for years, hip, back, and circulatory problems that quadrupeds don't have, agonizingly painful childbirth, and so forth: from a medical point of view, the changes to our body that were required for bipedalism are an absolute disaster. > > Having more than two legs would imply a lack of hands due to efficiency constraints (how many intelligent creatures have you seen with 4 legs and 2 arms?) > > > Our 4-limbed skeleton is entirely because we developed from a tetrapodal fish that happened to have four fins and a tail. Skeletal changes are, evolutionarily speaking, slow and hard. The formation of a new bone almost never happens, let alone the formation of an entirely new limb. This can happen as a developmental mutation (merging of two embryos, chimeraism), but not, I believe, as a genetic one, so the mutation cannot be inherited. > > A head containing the most critical sensory organs makes sense. > > > I agree - it's also important to have the sensors near the central nervous system, because nerve length relates to reaction time. However, there are other patterns such as that of the octopus' distributed nervous system, also seen in some of the larger dinosaurs. > > Having the primary method of vocalization in the head also makes sense > > > Agreed. Though really low bassy sounds might be better coming from as low as possible. > > Concentrating functions like eating/breathing/talking into one system is very efficient (again, virtually every organism we know of does this - certainly every dominant organism anyways) > > > We're the only organism I know of that does this without separation of the systems, and it's super stupid. Our descended larynx makes diving and speech easier, but makes choking to death common, and means we can't breathe at the same time as eat or drink. > > The most variation I can conceive of would be skin composition > > > This may be the saddest indictment of how modern educational systems kill imagination that I have ever read. > > they would spend tens or hundreds of thousands of years using their intelligence to craft environmental stabilizers like clothing and shelter, so having fur or even just tough skin would have become unnecessary long ago. > > > The only reason you can see our skin now is because of a past environmental pressure (I'd argue for a semiaquatic stage, others believe it was to improve cooling, or sexual selection). It was not due to clothes-wearing or the invention of AC (in fact, we now have to wear clothes because of our hairlessness). Bodily hairlessness is now maladaptive for civilized-us. Head hair and beards that have to be constantly trimmed and managed is also maladaptive. Head and facial hair that clearly signals age is maladaptive, unless aging is a sexual characteristic - which it is not, for most. In short, in a large population with no significant evolutionary pressures, and technological solutions like hair dye and beard trimmers to resolve any issues which might affect their reproductive success rates, "Unnecessary" is not an evolutionarily selective force. [Answer] The question is built on a large number of false premises. Once they are removed, the question no longer stands. The term "apex species" is used without defining it, with an implication that humans are the apex species. This term is normally used to refer to [apex predators](https://en.wikipedia.org/wiki/Apex_predator), and there are many apex predators on Earth, including crocodiles and some snakes. So, by example, yes, the universe actually "has a reason" (even this term is problematic) to develop apex species other than rubber forehead aliens. > > Without fine manipulators we would not be able to use tools > > > [Crows use tools](http://news.bbc.co.uk/2/hi/8631486.stm), without "fine manipulators", so this assumption is false. > > no sensible reason to develop tentacles on land > > > There are several errors here. One is that the assumption that intelligence will only develop on land. Dolphins and octopuses are counter-examples. Another is that there is no "sensible reason" (again, a problematic term, when discussing evolution) for tentacles to develop. This is mainly an argument from incredulity, but also ignores elephants' trunks which could be considered tentacles (for a broad definition of tentacle, as is appropriate here). Finally, it ignores other options, such as crow's beaks. > > There's no conceivable need for more than two hands that wouldn't be outweighed by the inefficiency of having to supply them with energy. > > > If that was true, there would be no animals on Earth with two hands and a [fully prehensile tail](https://en.wikipedia.org/wiki/Prehensile_tail#Animals_with_fully_prehensile_tails). As there clearly are such animals, this argument must be false. > > Being bipedal gives us a combination of balance, fast/slow modes of travel, excellent ability to overcome obstacles and chase prey or escape predators. > > > Despite these claims, four-legged, six-legged, eight-legged and winged animals are all very successful in their niches. Dolphins, octopuses, dogs and monkeys provide clear counter-examples where intelligence is found in animals that are non-bipedal. (I guess crows count as bipedal, but they have no hands.) > > Having more than two legs would imply a lack of hands due to efficiency constraints (how many intelligent creatures have you seen with 4 legs and 2 arms?) > > > Many oppossums, elephants and new world monkeys, are intelligent, have four legs and one arm-like appendage. It's not two arms, but shows the efficiency argument is wrong. > > A head containing the most critical sensory organs makes sense. Anything we've ever designed that's supposed to have good visibility is tall with all its sensor ability at the top (think air traffic control towers, lookout posts, etc). > > > Neither crows nor octopuses are tall, and yet are intelligent and have good vision, so again this argument is flawed. > > Having the primary method of vocalization in the head also makes sense because the higher up it is, the better it will be at projecting sound (assuming sound is the main method of communication, thank for pointing that out @TimB). > > > Crickets and cicadas create noise by rubbing their legs. Beavers communicate by slapping the water. Pistol shrimp use their claws. None of these animals have trouble projecting sound without using their head. > > Concentrating functions like eating/breathing/talking into one system is very efficient (again, virtually every organism we know of does this - certainly every dominant organism anyways) > > > Once again, this is an anthropocentric view of biology. [Collembola are more dominant than humans](http://www.bbc.com/earth/story/20150211-whats-the-most-dominant-life-form) and they take in some of the water they need through a hole in the abdomen. Another counter-example shows the conclusion is false. > > Do we have any reason to assume that any particular inteligent alien would have a markedly different body plan than homo sapiens? > > > Yes. We only have a limited sampling of species on Earth, but the most successful species are not human shaped, and most of the intelligent animals are not human shaped. Yes, the *most* intelligent animals are human-shaped, but that is only a sample of one. **In summary, each of the substantive arguments given in the question for why intelligent beings should be humanoid can be shown to be flawed using only simple examples from Earth. We are left with no compelling reason why aliens should be humanoid, except as a mechanism to save money in sci-fi film production costs.** [Answer] * Do we have any reason at all to believe they would happen in reality beyond just "we want more flavor"? Yes we do have a reason; the fact that the universe is a very large place. In my opinion a better question would be "Do we have any reason to assume that any particular inteligent alien would have a markedly different body plan than homo sapiens?" Which is a harder question to answer. Evolution is an unguided process that selects for traits that are advantagous in the environment that the organism is in at the time the trait is selected for. This makes it very hard to argue against any particular endpoint, since you would be making an argument that needs to take into account all possible histories that could have lead to that endpoint. Compare your "The most variation I can conceive of would be skin composition..." with the many irreducible complexity arguments that are out there(eg. ). In particular note that the spesific advantage gained by intelligence is probably not tool use. Rather it's likely the ability to understand and manipulate social networks. On to your specific points: * There's no conceivable need for more than two hands that wouldn't be outweighed by the inefficiency of having to supply them with energy. This is an argument from incredulity. Imagine a centipede that started using it's legs as manipulators, essentially making up the lack of fingers by having a huge number of "arms". * Being bipedal gives us a combination of balance, fast/slow modes of travel, excellent ability to overcome obstacles and chase prey or escape predators. This is not why we are bipedal. We are bipedal because we evolved from quatrupededes, and where in a position where it was advantageous to specialize two of our appendages for manipulation. (One could argue for the advantages of a quadrupedal body-plan for large creatures - certainly they dominate on Earth) * Having more than two legs would imply a lack of hands due to efficiency constraints (how many creatures have you seen with 4 legs and 2 arms?) See the scorpion in the other answer. * A head containing the most critical sensory organs makes sense. Anything we've ever designed that's supposed to have good visibility is tall with all its sensor ability at the top (think air traffic control towers, lookout posts, etc). Probably a point. There is probably an advantage to keeping sensory organs high. - Furthermore you want your sensory organs close to your brain, which implies a clustered design. * Having the primary method of vocalization in the head also makes sense because the higher up it is, the better it will be at projecting sound. Why do you assume your creatures communicate by sound? * Concentrating functions like eating/breathing/talking into one system is very efficient (again, virtually every organism we know of does this.) I think you have already answered this point. - "Virtually every"? In conclusion: If I would told that I was going to meet an alien tomorrow I would expect: * It to be walking upright * Having two arms * Having two legs * Having an identifiable head with sensory organs and brain * Having hands on it's arms with a small number of fingers on each hand. * Sensing smell, light and sound. * Relying vastly more on one of smell, light or sound than on other senses. * Having an understanding of math and logic. I would also expect to be wrong on at least one of the above points, simply for the reason that my sample size in formulating these expectations is 1 - which is far too small a sample to draw any conclusions from. [Answer] Actually there are plenty of examples of creatures with more limbs, in particular insects and arachnids. Obviously there are limitations to how large they can grow on our world but in an alien world creatures with a similar body layout could grow large enough to develop intelligence. The body plan of a scorpion for example: [![enter image description here](https://i.stack.imgur.com/20McV.png)](https://i.stack.imgur.com/20McV.png) So lets say on this world a creature similar to the scorpion started working on a more omnivorous diet. One of its claws starts adapting to work as a manipulator and gain fine motor controls while the other remains for cutting. At the same time they grow more social and become pack hunters, growing larger in size. With the advent of the pack they start gaining social skills and with it steadily increasing intelligence. They hunt in packs and work together to bring down larger prey with repeated stings and then eat the body. Before you know it you have something that looks nothing like a human but is growing towards sentience. It has one manipulating grasper, one cutting claw, a deadly sting, and the other attributes of a scorpion but is much larger and more intelligent than our earth scorpions. You could follow exactly the same process for many other alien creatures too. [Answer] Here's one clear example where the body plan would be very different: Fluid-environment intelligent life. Earth has several examples of relatively intelligent life forms that live in the water, such as octopuses and dolphins. These creatures have comparable levels of intelligence, manipulation ability (in the case of octopuses), etc., to that of apes. Therefore, it is not unreasonable to believe that an intelligent underwater life form could exist. Obviously, the body plan arguments only apply to land creatures. Bipedal? Vertical main axis? A sea creature would probably look more like a dolphin or octopus or something. --- Another example would be a intelligent creature which developed from a bird - it might have wings, instead of arms. --- There is a more general argument here, in addition to the specific cases outlined above. Every living thing any of us have ever seen evolved on Earth. Therefore, it's really hard to tell which qualities are necessary/effective for life, and which are necessary/effective for living on Earth. For instance, on a planet with a dramatically different level of gravity, different body plans would be most effective. Higher gravity? Lower to the ground, more spread out. Lower gravity? Maybe flying, maybe something resembling an insect, with thin fast legs. On a planet with a dramatically different system of heat generation, such as where the heat primarily comes from a molten core, rather than a star, underground living styles would be most effective, and body plans better suited to that situation would thrive. --- The list goes on. Your theories have the potential to be accurate for e.g. land-based intelligent creatures on Earth-like planets, but there is no guarantee that aliens we meet will fit those parameters. [Answer] > > Without fine manipulators we would not be able to use tools, and > there's no sensible reason to develop tentacles on land so that only > leaves hand-like clusters of extremities. > > > Or a tail. > > There's no conceivable need for more than two hands that wouldn't be > outweighed by the inefficiency of having to supply them with energy. > > > No conceivable scenario? How about 4 species on a planet, trees, supermegadeadly bears that kill anything on the ground, and two species of tree dwelling primates that are smart enough to use spears/clubs - one of which has 4 arms and a tail, and one of which has 2 arms. Who do you think would be the dominant species 10k years later? > > Being bipedal gives us a combination of balance, fast/slow modes of > travel, excellent ability to overcome obstacles and chase prey or > escape predators. > > > No, being bipedal gives us terrible balance and top speed. Go take a dog for a run. > > Having more than two legs would imply a lack of hands due to > efficiency constraints (how many intelligent creatures have you seen > with 4 legs and 2 arms?) > > > You are begging the question here, by assuming anything that hasn't happened can't happen, you come to the conclusion that the status quo is the only possibility. > > A head containing the most critical sensory organs makes sense. > Anything we've ever designed that's supposed to have good visibility > is tall with all its sensor ability at the top (think air traffic > control towers, lookout posts, etc). > > > Think drones, aeroplanes. You are also making some assumptions that the only senses the creatures could have are those that humans have. On earth, there are animals that can sense magnetism, can predict earthquakes, and many other things. Imagine a world in which the most dangerous and significant factor is frequent, deadly earthquakes.the most important sense wouldn't be sight from the head, it would be tremorsense in the feet. It could make sense to locate the brain lower down, the decrease the reaction time for signal to go from the feet to the brain and return. Or perhaps flight would be preferable. I can certainly imagine if there is only a single flying species, it makes sense to have eyes that look down, and a protruding head isn't necessarily the best option. > > Having the primary method of vocalization in the head also makes sense > because the higher up it is, the better it will be at projecting sound > (assuming sound is the main method of communication, thank for > pointing that out @TimB). > > > As TimB says, you are assuming speech Lets say your species has developed tremorsense to avoid earthquakes (see above), why not use that for communication? It would stop other creatures being able to 'hear' you if they have not developed the same sense. > > Concentrating functions like eating/breathing/talking into one system > is very efficient (again, virtually every organism we know of does > this - certainly every dominant organism anyways) > > > By every dominant organism, you mean human? Again, you are making some big assumptions. You say that in order to eat, the creature needs a mouth, but why does the organism need to eat? Trees get their energy without eating. You have made the assumptions that the animals are extremely similar to humans, and then have used reasoning to suggest that, assuming they are very similar, they actually need to be extremely similar. But there are so many alternatives. Another significant thing you have not considered, evolution does not produce the perfect beings, it generally tends to produce beings that are more suitable than their direct predecessors and current competition. [Answer] Without even going into each argument individually, there is a large flaw in your logic. You're assuming only the best possible outcome can and will end up fostering intelligent life. While this would make for easier argumentation, as it is often much easier to find the best solution than to count the amount of solutions. It is completely unrealistic. The first species to be sufficiently dominant in its eco-system and has the capability to mature its intelligence over subsequent generations is enough. You don't need anything perfect, you don't even need good, you just need good enough. [Answer] Most of the other answers have already covered the counterexamples to the arguments put forth in the question, so I will attempt to cover the biological theories behind it. The question assumes that all intelligent species will evolve into a humanoid body structure by [convergent evolution](https://en.wikipedia.org/wiki/Convergent_evolution) due to the humanoid body structure being the "best" structure for this purpose. To evaluate whether this assumption is a good one, we can look to examples of convergent evolution on Earth, and determine whether they produce similar body plans. ## Aquatic animals Water resistance is a major factor in the speed of animals that swim through the water, and therefore a commonly cited example of convergent evolution can be found in the similar body plans of dolphins and icthyosaurs, animals which evolved from different ancestors but nevertheless have the same streamlined ogival body shape. [![enter image description here](https://i.stack.imgur.com/O214C.jpg)](https://i.stack.imgur.com/O214C.jpg) Despite these similarities, however, the two animals are nevertheless very different. The icthyosaur swims by a left-right motion of its tail fluke, and the dolphin swims by a up-down motion. ## Flying animals Similarly, the [pentadactyl limb of flying animals](https://en.wikipedia.org/wiki/Convergent_evolution#Flight) is also cited as an example of convergent evolution. Different parts of the animal's limb became adapted into the wing structure in different animals, the pterosaur uses one finger, the bat uses four fingers, and the bird uses all its fingers together. Despite the fact that the structures are outwardly similar, their internal structures are extremely different. [![enter image description here](https://i.stack.imgur.com/HslQU.jpg)](https://i.stack.imgur.com/HslQU.jpg) Therefore, we can see that convergent evolution, even amongst animals that are already related to a large extent (ancient amniotes in the aquatic animals, ancient tetrapods in the flying animals), produces animals which are superficially similar in form but vastly different when analysed in detail. Furthermore, the [evolution pressures on intelligence](https://en.wikipedia.org/wiki/Evolution_of_human_intelligence#Models) are also much less specific to a certain body plan than water resistance or aerodynamic structure. Many theories for the evolution of intelligence exist, but none of them involve body plan. The most widely accepted evolution pressure theories involve a self-competitive [Fisherian runaway](https://en.wikipedia.org/wiki/Fisherian_runaway) process, which can occur in any kind of animal that has the capacity to compete intellectually with others for mates. There is no good *a priori* reason for the number of legs or limbs of an intelligent animal to be fixed to a specific number. As the previous answers have already shown, the [argument from incredulity](https://en.wikipedia.org/wiki/Argument_from_ignorance#Argument_from_incredulity.2FLack_of_imagination) is a very poor argument when it comes to imagining aliens. [Answer] [Stanisław Lem](https://en.wikipedia.org/wiki/Stanis%C5%82aw_Lem) is a very good example of an author who dedicated most of his sci-fi books to examine this very question, and created plenty of worlds inhabited by intelligent life which doesn't differ just in a [few facial features](http://tvtropes.org/pmwiki/pmwiki.php/Main/RubberForeheadAliens) from humans, but is so different from anything we've ever encountered that we might not even recognize each other as "life", much less as "intelligent". He often even gives detailed explanations about how these lifeforms could have been evolved. [Answer] You seem to be assuming that an intelligent organism would have to be a vertebrate. It wouldn't. The requirements for intelligence are a reasonable size to accomodate a big brain, social behaviour, and an ability to use tools. From an anatomical point of view it's unsurprising that (despite the relative lack of social behaviour) the most intelligent invertebrate is the octopus. It needs intelligence to make the best use of all those limbs. Octopi have been shown to learn by demonstration as well as experience (An octopus who watches another octopus solve a puzzle, such as getting food out of a screw top container, is able to solve the puzzle itself.) The main thing holding octopus civilization back is that their reproductive cycle means they never knowingly have contact with their offspring, and therefore have no incentive to care for them. An octopus that evolved live births would probably soon evolve good care of its offspring and a rich culture quite quickly afterwards. Holding back octopus technology is their rather stable environment. They have no need for shelter, as warm blooded humans in a cold climate do. On the other hand, if they start going to war, they will need weapons and castles. I imagine them forming a society like the Greek philosophers, with major advances in maths, and maybe less so in technology. Still it would be interesting to see what technologies they came up with, and that could be the subject of another question. > > Concentrating functions like eating/breathing/talking into one system is very efficient (again, virtually every organism we know of does this - certainly every dominant organism anyways) > > > Actually eating and breathing through the same hole (the throat) is a terrible piece of design. It means we can choke on our food. It comes from our vertebrate heritage, where fish's gills were joined to their mouths, so they could gulp water across them to breathe. As this was the only bodily opening available, the lungs were also accessed through the mouth. Arthropod and mollusc lungs have their own separate openings, which is a much better idea. [Answer] Humans evolved from primates, which evolved from small mammals that evolved from even smaller mammals that survived a cataclysmic event some 65M years ago. Rewind the evolution timeline, and pretty much everything alive originated from underwater life. One extremely interesting way to actually *witness* evolution, is to look at how a human embryo evolves in the first few weeks. We have two eyes because we're genetically programmed as such; we breathe through the nose (/we have a nose) for the same reason. If our ancestors weren't fish, our skulls wouldn't be structured the way they are; there's a reason our eyes start off on either side of our embryo heads, and for the "intake" end of our respiratory system to start off with a support for... gills. All vertebrae share a common ancestor, and that common ancestor's ancestor was a bacteria. Everything between that bacteria and the *Homo Sapiens* is a fine combination of trial-and-error adaptative evolution, over millions and millions of years, and with a great deal of luck - without that asteroid impact some 65M years ago, mammals would probably have never been given a chance to evolve and take over the Earth, and if nothing stood in the way of these giant creatures we called dinosaurs, who knows what could have happened. Being a biped is the result of millions of years of evolution, in a path that includes being a quadruped and growing such limbs as a result of adapting from an aquatic environment - with the advent of the need to move out of the water, most probably being nothing more than a fortunate accident. My own personal conclusion, is that alien life that would have evolved from a similar original bacteria, over millions and millions of years, with its own "fortunate accidents" and massive extinction cycles, has **no reason whatsoever to be anywhere similar to anything we know**. [Answer] There is a big trap when extrapolating from what you see on Earth: *all life on Earth shares a common ancestor*. Long before a group of ape-like mammals started evolving towards the intelligence humans currently have, there was a long history that *limited what was available*. All vertebrates share the same general body plan with a spine, hollow with nerves inside it, and a mouth somewhere near the top and an anus somewhere near the bottom. Not because that was best, but because that's what we started out with. A mutation that changes the body plan drastically will almost certainly die very early on after conception, because this body plan is the first thing that the embryo develops. The reason we ended up with this body plan was not because it was best for intelligence, but because some very early "fish" had it, and ended up becoming the ancestor of all later fish. Elsewhere, evolution has a completely different history. We can't make any assumptions. [Answer] I read some flavor text for StarCraft some time ago that explained the background story of the Zerg. I can't find the source, so this is by memory: The Zerg originated as parasites similar to [Captain Higgins](https://theoatmeal.com/comics/captain_higgins). They are worms that invade a host and manipulate its behavior. Through a Xel'naga evolution boost (which may be optional) their repertoire was enhanced to DNA manipulation. Need to crush a nut? Grow a fist made of bone. Need shelter? Grow a thicker skin. Need more shelter? Make a plant grow into a house. Need to move fast? Catch the fastest animal you can find, absorb the DNA, enhance it a bit. Need to be smarter? Grow a [bigger brain](https://i.stack.imgur.com/H6i49.jpg). Need to fly to space? Grow ... something ([Zerg can go to space](https://www.youtube.com/watch?v=AuVuPK3LkZQ&index=8&list=PL46C53738AFD03901)). Whatever is required is grown or adopted from creatures around the universe. The Zerg don't even have a body the way you described it, they change their form to whatever is useful at the time. Combined with a hive mind you keep a collection of creatures instead of tools for reoccurring jobs or grow from DNA as needed. Things like languages, politics, culture and vehicles were unknown to the Zerg and even after learning about those things they didn't adopt them much, but when they did find a useful design they enhanced and kept it. ![Kerrigan](https://i.stack.imgur.com/6vw3k.jpg) [Answer] Yes. You think too much within our human world. * You don't need tools for intelligence. "Uses tools" -> "Must have a certain level of intelligence" "Can't use tools" -> "No further implications regarding intelligence". * Yes, there is, if you, say, also use them for walking. * I'm not sure scientists are sure why we are bipedal, but one big reason I know is that's it's better for endurance. You can keep up a moderate speed for days at a time (not you, specifically. Me neither. But people in general if running was as important as being able to spell "specifically" correctly). Deer can't. They'll eventually have a heart attack and die if an animal like a human tracks it. No weapons necessary! But there is no reason intelligence could not evolve in an animal which is better at sprints (and then, say, hiding, or trapping it's pursuer). * First, examples to the contrary were given. Second you assume hands and legs *must* be separate. * Thinking/input complex: *sigh* What about hive minds? Just as a single example. For example cancer would be much less dangerous for such a creature (what do you care if a couple percent of your "cells" die per year?). Why not bees with some way to communicate, with hives reaching an intelligence as a whole? * "primary method of vocalization" "eating/breathing/talking" From where do you know they breathe/talk/eat like we do? What about a creature which communicates purely using pheromones? One which doesn't "eat" but one which drinks body fluids of other creatures? [Answer] Many people when dealing with the concept of extraterrestrial life make a number of false or incomplete assumptions. Firstly, the probability as far as we currently know is that life is just as likely to exist only on Earth and nowhere else, as it is to exist elsewhere. We have no frame of reference for 'What is the probability of life existing?' as no comparison exists. Given an identical Earth, with identical properties, we can still only give the probability of life being between 0 and 1. So to assume life would ever evolve in the same way is many levels further of not knowing the probabilities. It is just as likely that all planets in the universe that have life, evolve in the same way Earth has, as it is likely they have a completely alien idea of life, possibly too hard for us to even comprehend. How could we possibly know that the human-form is the most likely to exist? Think how strange the entire process of the body working is; `Vision:` Discrete quantized packets of energy flow in a sinusoidal waveform, hitting a lens to focus this 'light' onto a transducer, transforming the light's energy into a flow of electrons that will travel across millions of neural connections, acting like complex transistors with 100s to 1000s of possible states, thus forming a 2D representation from a 3D world (And this is a large simplification) So, why would it be likely that any of that would be the most logical process for a being to "see"? That just happened to be the way evolution began with, and it was better than anything that didn't have that. Why is our way of walking as a bipedal the most likely or efficient? Going to an extreme; Why wouldn't it be more efficient that a life-form would instead of "walking", bend space-time in order to move from point to point? Why does it need legs? How could you or I possibly know the efficiency or likelihood of that occurring? Perhaps this creature can harness zero-point energy... [Answer] I think that the answers already posted are great. However, they focus on examples of earth, which one could argue are not intellegent enough to count (which i feel boils down to moving the goal posts and 'not a real scottsman" arguments). Or they speak in very general terms. I still agree with both of them, but lets try another route, proof by counterexample. Already a list of presumptions made was pretty detailed, so I won't go into them, but one implied one was the presumption of land based intellgence. Lets imagine a world with an extremly heavy atmosphere, and limited solid mass. You would be crushed by pressure or roasted by heat before solid mass was found. In this world all creatures fly, or more accurate 'float' in the atmosphere, must like creatures in water, but without quite the level of resistance water provides. In this world a tall structure would likely be quite bad, it would not be aerodynamic. The need to float in a lower density air (compared to water) would likely require a more balloon like structure as well, larger species would have to have large but light bodies to displace as much gas as possible. appendages to manipulate objects would almost certainly not look like hands, which evolved from feet and thus are tied closely to land animals. Instead their 'wings', whatever structure they use to control their moment in three directions, would likely evolve into their means of manipulating objects, or perhaps grabbers used to catch prey (which in turn likely evolved from 'wings') This species would likely have a harder time leaving their home planet, due to difficulty of getting solid supplies to construct ships with, but could eventually find ways of doing so. They would look entirely different and work entirely differently, but they would make sense as a sapient species for the world they evolved in. [Answer] Your comment on [Mat's Mug](https://worldbuilding.stackexchange.com/users/13396/mats-mug)'s answer prompted a new thought and a slightly different answer to the others; turn the question the other way round. > > Dinosaurs, for example, ruled the earth for far longer than mammals > have, and yet they developed no technology at all. > > > Let's look at dinosaurs. Velociraptors are bipedal, with two hands, two legs, and a tall raised head and stance containing major sensory organds. Similarly theropods such as Allosaurus and T. Rex. And yet, as you say, they did not, in millions upon millions of years develop technology, or even, as far as we know, the beginnings of language. So, given the various species over the life of the planet with your proposed body plan that have **not** come up with technology, is it still likely that highly specific humanoid physical characteristics are so important as to be universal? [Answer] Most of the features you list are kinda convenient but not really critical. A few **are** critical. Despite all the answers, nobody seems to have pointed them out yet. It is really, really important, evolutionarily, to have something like a "head", where the main processing is done in close proximity to clusters of sensory organs that provide the most (and most timely) information. This lets you react quickly to stimuli. If you ever wonder whether reacting quickly, is a big deal, watch mongeese attacking a snake. Tiny, super-fast mammals are often able to kill a big fast snake because they have enough of an edge on speed. This is true everywhere in the universe. So, yes, they're going to have a head. And it's going to have to be not extremely tiny, because the universe is a complicated place and you need to have room to store your brain. And it's going to have to be positioned so that it can observe it's environment pretty well (i.e. view not occluded by the rest of the body). Second, it's really important to have some redundancy. If you're going to live long enough to amass a lot of intelligence, you're going to have to deal with a lot of potential problems along the way. Any organ that is so critical that you'll die without it in time T had either better nearly never have failures for as long as T, or you'll need two. So, two eyes and ears: almost surely, as the physics of capturing light and vibration require sensitive and compact organs, and those organs are key for rapid responses. It's easy for them to be somewhat out of sorts. Also, determining distance is really important and you need at least two to do it by parallax. But there's no really great reason you couldn't have more than two. (Does your mouth go near your head? Probably, because you want to make fast decisions about what you're eating and how you're biting it. But if your mouth is tough enough, or redundant enough, it might not matter.) There is also a very good reason for bilateral symmetry, which is that motion is difficult if you're asymmetric, and movement is really important. Witness the incredible success of bilateria vs. everything else when it comes to moving around. So if you have more than two of an organ or limb, it's probably going to be an even number. There's a possible exception for certain kinds of fluid-dwellers that look like octopi or jellyfish, but those would be in the minority. (And note that our octopuses are bilaterally symmetric.) Some way to communicate reasonably complex concepts is also essential, since it allows organisms to take advantage of each others' experience. It could be auditory or visual or even chemical or (for water-dwellers) electromagnetic. For instance cuttlefish are masters of visual display of information. So we can't really predict what form it would take, just that it's there. (Possibly in a form we would initially overlook.) All the details about two arms and limbs and bipedal and all the rest works okay on Earth, but could (and probably would) turn out differently. Even ability to finely manipulate the environment is fquestionable; social interactions drive intelligence so as long as there's *something* to do socially, you're probably okay. (Of course, being extremely clumsy makes you vulnerable to parasites and such.) (These constraints are only true, of course, until they start bioengineering themselves. Then all the former constraints may come off, and they could be anything that works physically with arbitrary materials.) So: head, yes, and up high or at one end or otherwise out of the way of the body. More than one eye and ear: yes. Bilateral: likely. Communications channel: yes. Everything else: probably different. [Answer] For all these answers, every one omits fire. Fire is absolutely vital, yet none but a few who post in comments consider it. Here is the crux of the matter. Fire is vital because of the energy boost involved in consuming cooked food. The human digestive system is 25% shorter and consumes proportionately less energy than the immediate primates, and is attuned away from the ability to digest cellulose at all. Cooking also kills numerous parasites. The full benefit of this would not be immediately available, but this puts rotting meat back on the table with far less immune system energy consumption. The changes involved free up energy for the intelligence required to wield fire. Fire is at least four steps in toolmaking. That is it is the equivalent of making a tool to make a tool to make a tool to accomplish a task. This in turn requires the intelligence to understand the steps, and the grasping hands to manipulate fire, and I'm pretty sure the loss of any significant amount of fur on the arms. (Wait what you say. Fire is vital for intelligence but intelligence is vital for fire. Yes I know. No wonder people don't want to talk about it. The claims are simply not made, but archeologists know where they find cooking fire it is human, and the ability to use fire is the best test of intelligence.) The fine development of the grasping hand and tactile sensation and the hand-eye coordination would tend to make the hand not-so-suitable for walking on (you want arthritic hands in short order, start developing the knuckle-wakers for fine work). This means unless you started with six limbs, you end up with bipedal. None of this, however, required an internal skeleton at all; however in this world there are reasons there aren't any large exoskeleton creatures. In answer to other claims, intelligence is the game-changer. Humans are the uncontested apex predator in all terrestrial environments that can possibly support a human (we can't live on insects), and now in the shallow oceans. You ask for a potential space fairing race. This immediately doubles-down on the need of fire. In addition, while I like the idea of an acquatic space-fairing race the essentials of setting one up appear insurmountable. Let us suppose for an instant the water-world with only a few islands, yet they somehow grasp for the stars (for them space is an ocean would seem more true than even to our storytellers). But the first building is the VAB. How do they refine metal enough to build? How can they ever discover rocketry without first the need of gunpowder? How could such a struggling race manage somehow to lift the first of their own with all the tons of water required (although I must say this makes recovery much less to fear). Once put the details to it, it just seems too hard. If you want a non-bipedal you are likely to end up with something like a large dog with an extra set of arms coupled to the skeleton with another set of shoulders just behind the ones for the forelimbs (before the forelimbs would likely be too front-heavy). [Answer] Perhaps at the microscopic level, intelligent aliens are group minded. Their intelligence could be proportional to their population and, if their DNA is anything like our own, they would grow in ways similar to cell division. They could form spores to protect themselves from the harsh environments of space and reanimate in fairer conditions. Cells can communicate through chemical signaling. Maybe this could be the major pathway used to communicate when cells coalesce to form a superorganism. They could achieve genetic diversity through cell specialization. With time, and natural selection, the macro organism would take a new form that might be less aware of the intelligence that it possesses for the benefit of cell specialization. But potentially, on the macroscopic level, they could look and behave like human. I say that only because the diversity of species here on earth is astounding, but humanity today has a much greater potential for intelligent (space-travel) behavior than it did yesterday and I can't say that for another species. [Answer] Take a good look at Animorphs. Originally, Author K.A. Applegate conceived the main "good" alien, the Andalites, to be similar to the popular "Grey alien", anticipating possible film or TV adaptation. Her editor wrote back that the Andalite was not interesting, so Applegate decided to make them blue Centaurs with seven fingers, three nostrils four eyes (two on stalks capable of 360 degree rotation) a scorpion like tail tipped with an extremely sharp claw (called a blade) and no mouth (they absorbed nutrients through their hooves). The main antagonists were an alien race of parasitic slugs that could interface with neural tissue. Their primary hosts were seven foot tall lizard men with claws at nearly every joint (we later learn that they were genetically engineered by a more advanced race who pretty much liked to make creatures that filled specific roles but look bizarre and fierce at the same time) and a centipede like alien with multiple claw appendages that were able to manipulate tools and a driving hunger so painful that they overwhelmed the Yeerk parasites, who normally don't change behavior because of host emotions. In fact, the Andalites on numerous occasions question how Humans are even viable as a species. We have no natural weapons of our own, bipedalism is unique to us (all other creatures portrayed as balancing by some other means, either a tail, having a wide base, or three or more limbs). One yeerk expresses confusion that Earth, in general, having such a diverse ecosystem is even more insane and we should never have achieved our dominance given the concept of self-doubt was unheard of by the Yeerks until the came into contact with the human mind (the first yeerk to identify this trait immediately sees the benefit of this almost immediately as it allows us to better question a course of action). Moving to more real world matters, a good number of biologists have noted that if intelligent life exists, it will most likely be arachnoid, not humanoid, in origin. This grouping is among the most numerous of animal life. It is likely that alien life will be a majority insect based. Among our own species, social insects meet a lot of the social and language concepts, but they are not communicating in ways we can ever be fluent in translate. (Bees use dancing, ants and termite languages revolve around complex chemical scents). Even our own human society didn't have the same technological leaps... The Inca are famous for their complex road networks that rival even those of the Romans... but they never invented the wheel (or at least developed it for purposes beyond children's toys, which is pretty indicative of all native American Cultures). From an old world perspective, this seems at odds with how technology progress, but recall the Inca lived in steep mountainous regions... the idea of a wheel never caught on because no one used it long enough to devise the next invention, brakes, that would prevent it from catastrophically rolling off a cliff). And without decent uphill propulsion, it was easier just to use more Alpaca's which already could carry loads up hills. The Mayans and Aztecs never even got to the road stage, because they never had access to beasts of burden until Europeans brought horses. But Mezo-Americans were regarded as having some of the earliest forms of Brain Surgery, developing techniques comparable to modern operations as early as the stone ages... in fact, when the first contact between Europe and The Americas occurred, these cultures perfected surgery to such a degree that patients had a 90% survival rate and many people had gone under the knife more than once... In the West, comparable techniques wouldn't be employed until the late 1800s-1900s (again, consider the regions... a good number of antibiotic agents used today are derived from plants native to South/Central American rainforests. The Old World could cut open a skull but could do little to keep it from being infected, so more advanced techniques like where is the safest place to make the incision, never developed). Take away tool use, and man's distinct advantage is its endurance. Our bodies are quite efficient when compared to other Apex predators and being omnivores means we can survive on just about anything we can get into our mouth. We may not be the fastest swimmer or the fastest climber or the fastest runner, but we have "best two out of three" against most of our superiors in any one category, and even then, they won't do it for long. Humans are the fastest animal in an Ultra-Marathon (a 100 mile run) and while other animals can outspeed us, we can outlast them at a sustained pace. There is a biological reason for our bodies beyond just supporting a large brain. Finally, just one quip I like to point out in theoretical aliens, of all the animal kingdom, Humans are one of only three species engages in sex for pleasure. If aliens exist, the stereotype of hyper-sexualized fanservice aliens is likely to fall on humanity as the rest of the galaxy thinks we're way too obsessed with procreation and our planet becomes the Pleasure Planet for the alien deviants. Evolution does not go to any specific point. In fact, the reason why human intelligence never evolved in other animals is the brain capacity needed is inconducive to survival. Human youth are much more vulnerable for much longer because our brain takes longer to develop (full adult human development has always been decades versus apes and monkeys, which are years). But, the fact that we hunted by a combination of chasing our prey to the point of being unable to run any further, rewards the individuals who can figure out how to reduce that hunt-feast time. Some of these traits would be better mobility and stamina, but cleverness to end the chase sooner... humans are one of the best animals at ranged attacks. A gorilla can throw something at 20 miles per hour. A human can easily throw with three times the speed, and humans who are trained to throw can put as much as five times the speed behind an object. But it's not enough to throw an object, you need to hit your target, which is rewarded by better eyesight, an ability to attain a height advantage AND throw an object reliably while achieving the height advantage and not have the resulting force knock us over. This also develops an ability to notice minute changes in the handling of throw-able objects, the capacity to realize that success relies on hitting not where something is but where it is going to be, which requires a finer attention to detail. All of these lead to overdeveloped fore-arms with less developed hind legs. Alternatively, having buddies throw rocks will also help, which requires a need to communicate complex instructions. These things weren't isolated developments... Humans are not Pokemon... Neanderthal does not learn throw at level 21, evolve into Homo Sapien at level 36, and learn Spear Attack at level 55. These all developed simultaneously over the course of millions of years where those who were better able to live were better able to have children who in turn would better be able to live. Again, tool use is quite common in the animal world. In addition to apes and birds using sticks to get termites, Dolphins are known to use sea sponges to protect their noses while digging for prey in abrasive sea floor sand. Otters are known to use rocks to break clam shells and identify "My Rock". They also use kelp to anchor themselves to a location while eating or sleeping. Dogs are quite capable of using certain human tools to their ends (my own dog has taught herself how to open door handles). Language is even more widely used in the animal kingdom. I mentioned bees and ants (depending on the lasting effect of ant chemical markers, Ants could possibly count as having a written language, which is leagues more advanced than several of our closest genetic relatives). Dolphins and whales also have complex songs that communicate over vast distances. Prairie Dogs not only have a complex form of informative barks that has been mostly parsed by humans, but regional dialects have been observed between multiple clans. Once again, what separates domesticated dogs from Wolves isn't the capacity for language but the degree of information domesticated dogs can transmit. A Golden Retriever has the language capacity of a three year old and are able to "converse" with humans by a series of barks and body languages. The purpose of a domestic cat's meow is used primarily to facilitate communications with primary auditory communicating humans and body language communicating cats. A wild member of the cat family or feral domestic cat rarely meows, and when they do, it is never in the range of tones that a domestic cat produces, making this an example of a constructed language, with a degree of accuracy that humans can parse the tonal meows... If I were to describe a sound a cat makes as a "mew" you instantly get an idea of the cat in a calm state of mind versus what a "Yeow" is a cat that is distressed in some way. Even some repetitively simple mating displays can count as languages. After all, language is the reliable transmission of information from one individual to another. "I'm sexy and I know it" and "Hey there, stud" may be quite simple, but it's still transmitting that information. After all, we humans do recognize a statement is being made by showing off one's buttocks. So we must acknowledge that when a firefly does it, it is conveying a message of equal intelligence to one that is conveyed by a Frat Bro. Human intelligence developed to provide a specific advantage to survival. At its core, it was the idea that humans could outperform a much more physically superior foe AND do it quickly and with minimal threat to ourselves and our own. Our intelligence facilitated survival, but it also facilitated the survival of ants and grass. Perhaps out there in space, there is an animal that is capable of intelligence equal to our own, but it might not have evolved in the same way as us or to facilitate the same niche as us. [Answer] A large colony of ant-like insects could in principle implement a large neural network. Such a colony could then control its local environment, make tools, etc. A civilization comprising of many such insect colonies could arise. They would be able to communicate with each other a lot better than we can, because two such neural networks can interact with each other in a much more direct way. [Answer] "Without fine manipulators we would not be able to use tools, and there's no sensible reason to develop tentacles on land so that only leaves hand-like clusters of extremities." This is assuming that intelligence has to evolve on land when there is no reason that it must. Also there are other types of appendages that animals use to manipulate their environment besides tentacles and hands such as claws, elephant trunks, and the beaks of birds. "There's no conceivable need for more than two hands that wouldn't be outweighed by the inefficiency of having to supply them with energy." Octopi have eight tentacles and they use all of them for grabbing things so this assumption is false. "Being bipedal gives us a combination of balance, fast/slow modes of travel, excellent ability to overcome obstacles and chase prey or escape predators." Many animals that aren't bipedal are much more agile than us so this argument isn't really valid. "how many intelligent creatures have you seen with 4 legs and 2 arms?" When it comes to organisms having the same level of intelligence we only really have a sample size of one so what we see in humans doesn't say anything about organisms that would have the same level of intelligence as us. "A head containing the most critical sensory organs makes sense. Anything we've ever designed that's supposed to have good visibility is tall with all its sensor ability at the top (think air traffic control towers, lookout posts, etc)" There's no reason an intelligent life form at the same level of intelligence as us would need good visibility. "Concentrating functions like eating/breathing/talking into one system is very efficient (again, virtually every organism we know of does this - certainly every dominant organism anyways)" The only animals that do all three through the same system are humans and the only animals that make noises through the same system that they use to eat are vertebrates so this has only evolved once. Squid have their gills separate from their mouths. Insects make sound by rubbing different body parts together and moving their wings and they breath through air holes along their exoskeleton so animals can make sound without using their mouths. Also aliens wouldn't need to use sound as a means of communication but could use bioluminescence. [Answer] Dewi Morgan's answer is my personal favorite, so far, but I'd like to take a crack at answering the OP's question, using the methodology Dewi described, and I decided to apply it to a scorpion based species, being inspired by the comments of by Tim B: [the] ancestors [of the hypothetical spacefaring species] were: members of the group of single-celled organisms which, on dividing, stayed together in a colony, rather than dispersing. Eventually, individual cells became specialized. Members of the group which laid down support structures on the inside (vertebrates) rather than the outside (arthropodae). This made [them] [destined] to be a dominant species on the planet, as the creatures with exoskeletons ruled [their] world, and likely always will, vastly outnumbering [other animal groups], out-weighing [other animal groups] in terms of biomass, living in a far wider range of environments, outdoing [other animal groups] in just about every possible interpretation of survival. Members of the group which lived in seasonally flooded mangrove swamps or tidal basins, so were regularly exposed to air, became [amphibious] (not to be confused with amphibian) and eventually began to spend the majority of time on land... though naturally [it was] millions of years [before reptiles, birds, mammals, and other animal groups]. Members of the group which [did not] invest in internal maintenance of body heat, which served [them]well when the [vegetation plagues wiped out the high energy food sources required by] the ones who'd chosen external thermoregulation, [and so caused their near extinction as animal groups, with only the most primitive, non-specialized, variants able to adapt and begin a new evolutionary path, far too late to compete with the dominant arthropodae]. Members of the group of tree-climbers who became [primarily ovivorous], so had ample supplies of essential fatty acids for surplus brain growth. Members of the group of large-brained [ovivorous arthropodae] who were social, adventurous, and inquisitive enough to start using tools and sharing the abilities they gave and were opportunistic and gregarious, always looking for an opportunity to improve [their] lot. Members of the group which [had enough sets of appendages that they were able to specialize one set of appendages for tool use (which later included writing) and another for both gestural and later audible communication, and still have enough for locomotion and other basic survival needs, instead of having them atrophy away like some other more primitive species], such that complex "speech" could be developed, and thence storytelling and passing on of knowledge, ]including the previously mentioned writing]. It's language -- and more importantly, the preservation of knowledge that it permitted -- which meant [aviculture] became a thing, and later, sharing of tool designs, mathematics and science led to the industrial revolution. [... spacefaring ... ] As far as I can tell, this meets all of your criteria: intelligence, apex predator/species, could continue to spacefaring status, and addresses the body plan question. In my imagination, this leads to a cold blooded species resembling an oversized mix between a scorpion and centipede, having an exoskeleton, compound eyes, or multiple groups of eyes, mandibles not suited for verbal/audible communication, no significant need for olfactory sense organs at all or externally visible auditory organs, vibrations could be detected in many other ways, skin, hairs on the body, etc. It has 5 to 7 separate pairs or sets of appendages, some customized for specific tasks, like the claws of a scorpion for one task, and the legs for another, but with more complexity and variation in each set. The fact that it's cold blooded allows for efficient energy conservation required to power multiple appendages in a single organism. In summary, this is a fully-explained logic showing why a significantly different "style" of organism would end up not only being the dominant species on its planet, but be successful enough to develop space-faring technology. [Answer] > > *Without fine manipulators we would not be able to use tools, and there's no sensible reason to develop tentacles on land so that only > leaves hand-like clusters of extremities.* > > > "on land"; there is no reason why intelligent life could not develop > underwater instead (in fact: octopi and dolphins here on earth are > intelligent enough to be sapient) > > > *There's no conceivable need for more than two hands that wouldn't be outweighed by the inefficiency of having to supply them with energy.* > > > Have you seen how many manufactoring processes use clamps and grips of > some kind (especially in carpentry); having more hands makes it a lot > easier to hold a plank in place, place a nail against it **and** > hammer it in place > > > *Being bipedal gives us a combination of balance, fast/slow modes of travel, excellent ability to overcome obstacles and chase prey or > escape predators.* > > > Bipedal balance takes rediciulous amounts of energy, quadrapeds have > better and cheaper balance. Plus; horses are perfectly capable of > balancing, jumping and running away > > > *Having more than two legs would imply a lack of hands due to efficiency constraints (how many intelligent creatures have you seen > with 4 legs and 2 arms?)* > > > Why though? this builds on the claim that "more than two hands is not > worth the energy", which is debatable. I will return to the octopus; > it has 8 hybrid arms/legs, and it is intelligent. > > > *A head containing the most critical sensory organs makes sense. Anything we've ever designed that's supposed to have good visibility > is tall with all its sensor ability at the top (think air traffic > control towers, lookout posts, etc).* > > > Partially true, but vision is the only one that benefits from being at > the highest point of the organism; all other senses can be pretty much > anywhere (although keeping smell away from the anus seems practical) > > > *Having the primary method of vocalization in the head also makes sense because the higher up it is, the better it will be at projecting > sound (assuming sound is the main method of communication, thank for > pointing that out @TimB).* > > > You already mentioned that sound need not be the main communication > method; but height is not as important for projection as you might > think. In fact; if the mouth is facing "up", it can project in every > direction at once, instead of in the direction the "face" is facing; > this is very useful in larger social groups > > > *Concentrating functions like eating/breathing/talking into one system is very efficient (again, virtually every organism we know of does > this - certainly every dominant organism anyways)* > > > concentrating eating and breathing is a **terrible** design; it allows > the organism to choke. Also, depending on the diet, the mouth might be > occupied for long periods of time (see: snakes, who have a breathing > tube under their tongue to breath while eating). > > > We expect and display other lifeforms as *vaguely humanoid* becouse that is what we know, and it allows the (human) protagonists in fiction to share air and tools with the aliens. There is, however, no scientific reason why it *should* be so, and there are so many viable permutations even on earth that we can be pretty sure that aliens *won't* be humanoid [Answer] One of your assumptions is that such a creature would both sense and communicate in the same way we do. However, imagine a creature that lives in the dark, perhaps in a cave system. One possible evolutionary process might have it communicate by radio waves. Imagine sensory organs all over the skin which produced radio pulses and detected reflections as a means to navigate. I don't think it is hard to imagine an evolutionary process that would allow for this. Perhaps they ingest a type of mineral that naturally produces short metal fibers which were excreted through the skin. OVer time these might pick up a signal causing an electrical potential affecting, for example, sodium density in cells, and from this extremely basic beginning an evolutionary ramp could build a phased array radar of sorts. Such a creature would have a very different body plan, their sensory objects distributed over their skin rather than concentrated into single organs. Moreover, it is not hard to imagine that they manipulate their signals as a means of communication instead of sound. In a sense this is similar to the telepathy that seems all to common in SciFi. Because of the speed of radio waves this would not give a very fine sensory detection structure, but finer manipulation could take place with dermally extruded fibers that can detect small movements, much like whiskers, and perhaps a related series of prehensile manipulators. So imagine this creature has no hands at all, but instead is has cylindrical body covered in small worm like protrusions that can be moved and detect touch. Essentially the body has no hands but is covered with thousands of fingers. Moreover, instead of bipedal locomotion it doesn't walk, it rolls, using the "fingers" to manipulate and control the rolling. With a non skeletal body (see below) this may well better adapt them to movement in the rocky unreliable surface of a cave. Much as an octopus's tentacles are controlled independently from the brain, each finger might have its own neural system, and the brain power would be distributed throughout the body rather than centrally. Moreover, since it rolls and is small, squat and cylindrical, it is less clear that it would need a skeletal system. Without one it could squeeze through small spaces very effectively, which might be useful given our premise that it lives underground. In fact the system might have various muscular systems that allow it to reshape its body. For example, it might be able to extrude out a longer appendage out of its body by filling a cavity with "blood" (for example, like a penis), and because the surface is coated with fingers, give a very useful type of "arm", and there is no reason that it could have six or more arms pointed in different directions, not so much as preformed appendages, but as a natural ability to extrude parts of its body. Anyway, just a few thoughts. I think there are a lot of unjustified assumptions in the original question. [Answer] My ideas that make these aliens most unlike humans based on them needing to space travel. This requires at least propulsion and rocketry tech (if we assume they can do calculations in their head like those black women in that movie Hidden Figures). So for chemical propulsion: depending on their worlds conditions like ambient temperature, hydrogen as rocket fuel requires cooling thru helium to keep it from escaping vehicles. So at a colder world, these parameters can affect what fuels they use. However I don’t believe it will affect other things like the energy produced by burning fuel might still require to have steel and other materials to contain it and to direct the engines. I don’t have in depth knowledge but my answer is still better than others on here ]
[Question] [ Let's assume, without revoking any of today's science, that the world is a simulation. What would a bug look like? I'm assuming that "the eiffel tower suddenly being bent at 45°" is rather unlikely, the same way you don't see a bunch of clowns appearing in the middle of a game of need for speed. So what is likely? * repetitions / deja-vus? * changes in gravity / speed of light? * ... [Answer] [A bug is just an undocumented feature.](http://catb.org/jargon/html/T/Thats-not-a-bug--thats-a-feature-.html) Anything we see from within the simulation is just going to be a part of the simulation. The only way to tell that what you see is a bug is by knowing what the expected behaviour of the program is, and god alone knows what that is (literally, in this case). Even seeing the Eiffel Tower do a dance would more likely be caused by the interference of whoever is running a simulation, rather than a bug in the simulation itself. Furthermore, assuming that the universe is simulated at the level of elementary particles, bugs would be most likely to show up there. It would be hard to trace how these bugs would affect the macroscopic world, and we'd probably just see them as particularly bizarre rules. Even if your neutrons occasionally violated the law of conservation of mass and disappeared, physicists wouldn't cry out "The world is wrong!" They'd figure out when and why this stuff happens. That said, here's a few common bugs that simulation software written in a language like the ones we use today could have. In all cases, I assume that the simulation manages to not crash. Also, various bugs assume different things as "fundamental" -- all this probably disagrees with real physics somewhere. * The machines running the software may run out of memory. If something were to split into multiple pieces, some pieces may mysteriously vanish. * Memory may be managed incorrectly, resulting in two objects appearing to exist in the same place in memory (not space!). Influencing one would influence the other as well. [Wait, that sounds familiar...](http://en.wikipedia.org/wiki/Quantum_entanglement) * The time counter [may roll over](http://en.wikipedia.org/wiki/Year_2038_problem). [If the universal constants change](http://en.wikipedia.org/wiki/Physical_constant#How_constant_are_the_physical_constants.3F) over time, this could cause them to be reset to what they were at the Big Bang. I suspect humans wouldn't survive, though I'm not sure. * The world may have a [maximal precision](http://en.wikipedia.org/wiki/Floating_point#Accuracy_problems). In that case we can observe a particle at point `a`, or at point `b`, but not anywhere between the two. Or maybe [a particle can have energy level 1, or 2, but not 1.5...](http://en.wikipedia.org/wiki/Energy_level) * If the system is distributed, connection problems may lead to synchronisation issues. That is, those things simulated on server A see one sequence of events unfold, while those on server B see a different sequence, and then these are somehow merged into a single timeline. * Memory corruption can make things suddenly change value. That's not very specific, because memory corruption *isn't* very specific; pretty much anything could happen, though it would probably be a lot of chaotic changes. It is unlikely that any of the above would be able to explain magic in the usual sense of the word. Most magic is highly structured, allowing you to create and direct complex systems. A bug that lets you shoot fireballs is very strange indeed: it basically means the universe "knows" what a fireball is and can keep one together for you. In a universe built up from particles, this is not going to happen reliably by mere chance. --- In response to the suggestion that a different level of simulation would be more interesting: that could very well be the case. I just can't imagine how it would fit. It is not that hard to suppose that quantum phenomena are fundamental and that they somehow add up to normality. I'm not a physicist and don't know *how* this happens, but I believe that's how it happens in reality, and so I'm willing to believe that simulating quantum phenomena will also simulate normality. Going in the opposite direction is much harder. Suppose the main objects in a simulation are living beings. For some reason, lower-level phenomena are still observed. I see two ways this can play out: The low-level phenomena may just be there for décor. They can be observed but they don't have any further effects on reality. This can be seen (at a somewhat higher level) in strategy games, when a unit constructs a building. The animation gives the impression of work being done, but it's just for the sake of the viewer. The building will go up even if the animation is changed to show something else. In such a case, learning about how low-level things behave would give you only very tentative predictions about how the world behaves. Things like chemistry would be approximate at best. Alternatively, the universe may be able to add arbitrarily precise details to any place which is observed, *and* these details have to have an actual effect on reality. The problem is that any inconsistency in these effects with the macroscopic approximation leads to observations influencing results. Effectively, you end up splitting everything into three "sizes": * The décor: you can see, but what you see doesn't mean anything. * The inconsistent: you can see, but your results change if you do. * The normal: you can see, and can explain everything in terms of the smallest "normal" level. If you put molecules at the normal level, the behaviour of humans is going to follow from the behaviour of molecules. If you put them at the inconsistent level, chemistry isn't going to work quite as well as it does. You can't have your cake and eat it too. [Answer] If a universe is a simulation, then, logically, it must have all the natural laws built into it. Agreed? Now, if it is a [deterministic universe](https://en.wikipedia.org/wiki/Determinism) - that is a universe where, theoretically, you could predict its entire future if you knew everything about it at a certain point in time - these laws would be all that is needed to run the universe. It's sort of like [The Game of Life](http://en.wikipedia.org/wiki/Conway's_Game_of_Life) - you input some data and let the thing go. Now, we live in a universe where [quantum mechanics](https://en.wikipedia.org/wiki/Quantum_mechanics) exists, and thus probability exists. This has given a lot of people a lot of headaches, because there are loads of events we can't predict. In other words, you would have a harder time programming in natural laws than you would in a deterministic universe, because you would have to determine some random variables. If a universe is a simulation, then there would have to be an algorithm running in the computer(s) controlling it that [determines these random variables](https://en.wikipedia.org/wiki/Random_number_generation) - which would not make them random at all. In a deterministic universe, it would be easy to see a glitch. In a certain spot at a certain time, some phenomenon would occur that violates at least one law of science. For example, perhaps a falling ball moves a few nanometers to one side when it shouldn't have. Given the complexity of a large enough simulation, this could happen quite a bit at small scales. Maybe a photon travels in a vacuum at a slightly slower or faster speed than it should have. Perhaps a new particle appears (or disappears) into (or out of) thin air. Any of these things could be a bug, and they would probably happen a lot. But they would be so minor. It would be very rare for large-scale bug (e.g. the Earth suddenly moves 10 million miles in one direction) to happen. But we live in a universe where quantum mechanics rules on some scales, which gives us a very nice little loophole. If there was a bug, it could *actually follow the rules of quantum mechanics*. How? Well, the [Heisenberg Uncertainty Principle](https://en.wikipedia.org/wiki/Uncertainty_principle) says in part that conservation of energy can be violated on tiny scales for tiny amounts of time. So a particle suddenly appearing and disappearing could actually fit right in. There is a tiny probability in the universe that a lot of odd things could happen - [quantum tunneling](https://en.wikipedia.org/wiki/Quantum_tunnelling), for instance - that shouldn't. A bug could masquerade as any of these. So it's fair to say that small bugs could happen that would merely appear to be quantum phenomena. We would write them off as products of uncertainty and chance, and they would go by without anybody thinking that they were bugs. And in a simulation, small bugs would probably be very likely. --- I'm a bit bored, so I thought I might come up with a list of some of the bugs that might show up in the simulation. Taking some inspiration from the [Wikipedia article on software bugs](https://en.wikipedia.org/wiki/Software_bug#Common_types_of_computer_bugs): * **Infinite loop** - I guess the equivalent here would include time travel and [all the assorted issues](http://h2g2.com/entry/A1126595) that come with it. This could include [time paradoxes](https://en.wikipedia.org/wiki/Temporal_paradox), which give everyone headaches, or [closed timelike curves](https://en.wikipedia.org/wiki/Closed_timelike_curve), which also give people headaches. Both would involve odd problems with [causality](https://en.wikipedia.org/wiki/Causality_(physics)) - that is, either one thing causes another thing which causes the first thing or one thing causes another thing that makes the first thing impossible. Savvy? * **Division by zero** - This would be guaranteed to annoy the runners of the simulation. It annoys the heck out of me when I accidentally do it with a pocket calculator; on a scale like this, it would be catastrophic. But what would a manifestation of division by zero look like? Well, a [singularity](https://en.wikipedia.org/wiki/Gravitational_singularity), probably. If they try to simulate what happens at the exact center of a black hole. . . Ouch. The computer wouldn't be able to handle it - just like if you asked a computer to figure out $f(0)$, where $f(x)=\frac{1}{x}$, if the computer wasn't pre-programmed to know that such a calculation will always lead to an undefined quantity. * **Incorrect code transfer** - This isn't really a bug so much as an error on the part of one of the programmers, and it might not even turn out to cause a problem. Say I (one of the people working on the simulation) was assigned to transcribe the equations of what we, the simulated people, know as [general relativity](https://en.wikipedia.org/wiki/General_relativity), to the final program. I would have to transfer the main equation, > > $$R\_{ab}-\frac{1}{2}Rg\_{ab}+\Lambda g\_{ab}=\frac{8 \pi G}{c^4}T\_{ab}$$ > > to the program. Now, I would also have to transfer some of the intermediate steps, too, such as calculating the [Christoffel symbols](https://en.wikipedia.org/wiki/Christoffel_symbols). Let's say, though, I didn't use the concept of [Einstein summation notation](https://en.wikipedia.org/wiki/Einstein_notation) but did everything out by hand. Let's also say that while I translated (in spherical coordinates) > $$\frac{1}{2}\Gamma \_{abc}=\left(\frac{\partial}{\partial x^c}g\_{ab}+\frac{\partial}{\partial x^b}g\_{ac}-\frac{\partial}{\partial x^a}g\_{bc}+\right)$$ > correctly for $\Gamma\_{ttt}$, $\Gamma\_{tt r}$, $\Gamma\_{tt \theta}$, and so forth, I made a mistake for the case of, say, $\Gamma\_{rt \phi}$. This would mean that the computer would make weird calculations that it shouldn't have, that could throw everything off. Now, the reason I said that this might not count as a bug would be that this program is like The Game of Life: you write up the laws and click 'start'. So that error would simply *become* part of the physical laws in the simulation. It wouldn't make sense, but it would be a law nonetheless. > > > [Answer] There's a niche branch of research within theoretical physics that deals with exactly this sort of thing: if the universe were a simulation, what would be the physical effects of limitations in the underlying system? As an example, a few years ago [this paper](http://arxiv.org/abs/1210.1847) by Beane, Davoudi, and Savage got a lot of coverage in science media and blogs (much of it rather questionable, by the way). The paper assumes that the universe is simulated on a Cartesian grid in a particular manner, and identifies three consequences we might observe due to the nonzero grid size: * a modification to the magnetic moment of the muon * an inconsistency between different methods of measuring the electromagnetic coupling * anisotropy (i.e. a dependence on direction) in the maximum energy of cosmic rays If I may give a brief self-plug, at the time I wrote a [blog post](http://www.ellipsix.net/blog/2012/12/yes-virginia-the-universe-is-probably-real.html) that explains this in some more detail. This all assumes that the simulation works kind of like [lattice QCD](http://en.wikipedia.org/wiki/Lattice_QCD), namely that it simulates the fundamental quantum fields rather than individual physical objects. There's no reason one *has* to make that assumption, of course. But real-life experience suggests that creating a simulation which is accurate across the full range of length scales, from the structure of protons to the entire universe, is very, very difficult on the programmers if you use any method other than just simulating the basic ingredients. It's a good bet that if you want to simulate a universe, rather than coming up with tricky algorithms to represent objects, it's easier to just build a bigger computer. This means the "obvious" bugs you might think of, like disappearing objects or different parts of the universe behaving identically, just won't happen. [Answer] I'll attempt to answer this as a programmer who deals with bugs daily. ## How might we simulate a universe? The universe is big. If I was trying to simulate it I would make some optimisations to my code. I would be tempted to only simulate in detail the portions of the universe that anyone is actually looking at, to the level of detail with which they are able to perceive that portion. I would make statistical generalisations to determine how things change when they are not being looked at. Objects that are not looked at would not be rendered so to speak. Interestingly this actually ties up pretty nicely with the result of the double slit experiment. This is rather like the way we encode a jpeg. Only the interesting regions are stored in detail, the lower detail sections are "derezzed" so to speak, and we get the blocky jpeg corruption we are all familiar with. Imagine a dynamic resolution resolver that modifies the detail of any particular region of space depending on whether it is being observed. ## Preprocessing I might also be tempted to engage in some preprocessing. I would prerender certain portions of the universe and mark them as such. I would make distant stars essentially static objects, since we can't perceive them in detail. I wouldn't bother rendering the dark side of the moon for example, or the core of the planet. ## So what sort of bugs might we see? Well we might expect to see different types of bugs depending on which portion of the code we are looking at. The detail rendered environment would likely be sound. When an object is not perceived we would experience the consequences of whatever simplifying assumptions the coder made about the universe and how it might change. * We might perceive a disjunction in the universe, a crack if you will, where time and space are not correctly joined up. * We might start to see unrendered portions of the universe, perhaps regions of the universe marked as rendered are actually not rendered at all. Perhaps an astronaut in orbit round the moon finds the dark side is just a blank void, impossible to look at or perceive. * We might see errors in simple laws of the universe. Perhaps we put the car keys down, turn away, and when we turn back they are missing (again a common experience). * We might see errors in arithmetic in unrendered portions of the universe. We might find 2 + 2 = 5, literally take two objects then another two, and we have five in our hand. * Complicated regions of space might crash, for example, your ipad might derez, and then reappear blank and clean. * Perhaps gravity or fire might occasionally not act correctly on an object if it is not observed. An object might be left suspended if the program fails to recognise that it's support has been removed, then crash to the floor when a person enters the room. * You might see shadows of objects or people which are no longer there. Perhaps objects leave a hole, or a lightwell. * Damaged objects might be lost and replaced with a clean version from a buffer. A damaged car might become like new again. A scratch in some paint might be erased. * At a more extreme level, a human might completely disappear, all memories of that person erased from the program, except perhaps a ghost, a shadow. ## Pausing It's also interesting to consider that if the universe were a simulation, and our minds constructs within it, our perception of time would be tied to the simulation. It would be possible to perhaps pause the simulation for a thousand years and none of us would even notice. It might take a billion years of real time to render a single frame, and none of us would be any the wiser. This assumes of course that time and space exist outside of the simulator. Perhaps the real world is something altogether more exotic. ## Reference <http://en.wikipedia.org/wiki/Double-slit_experiment> [Answer] It would look like this: ![bsod](https://i.stack.imgur.com/VzqDv.gif) Upon looking into the sky you would see this message. Soon, after a sensation of deja vu, everything would rewind 90 sec (last backup is copied in) and everything would go on as normal. Actually this already happened before, when the dinosaurs died. Unfortunately the universe bugged right into the middle of a backup, so the operators lost a lot of data. They decided on a workaround simulating a meteor strike on earth. References: Adams, D. (1985) *The Hitchhiker's Guide to the Galaxy* [Answer] \*ahem... ![enter image description here](https://i.stack.imgur.com/LK9ex.jpg) Theoretical rendering of a black hole, which can *supposedly* divide by zero. [Answer] In general, calculations that simulate all particles at once are quite expensive to run. Most simulations therefore prefer to use shortcuts for calculations. Instead of simulating every single atom, a bunch of atoms are simulated together. That produces errors that derive from calculating every atom individually. Another way to save computational resources is precaching. Instead of running a calculation every time, you run it once and give the same result every time it gets run in the feature. Allowing magic would mean that the simulation takes into account the mental states of people to make decisions. If nobody is looking at a particular place, then the simulation doesn't invest much resources into getting every little detail right. Whenever Randi makes a high stakes experiment the simulation engine pours a lot of computational power into it to make the results come out right. If however nobody does real scientific investigation, paranormal glitches can happen. Magic is nothing more than the simulation taking into account of the mental state of the people in it. Randi strongly believes that his experiments will turn out a certain way, so they turn out that way. On the other hand there could be other people who also get results be focusing their attention on getting a certain result and then the simulation calculating the world to get that result. If you start with that frame you can adopt a lot of ideas out of the "Law of Attraction" community. That community mistakenly interprets the Observer effect in quantum dynamics to mean that we live in such a world. [Answer] I didn't see these ideas posted so I thought I'd put them here. **Spotting a Simulated Universe** If the Universe is indeed a digital simulation, then the Universe computations will be done with only a certain level of precision. Since the Universe must do this computations everywhere, it should be possible for someone doing computations within that Universe to do computations at a higher level of precision for very specific cases then that used by the general Universe simulation computations. To the researcher, this would look like small but unexpected & unexplained deviations between our calculations of a behavior and the observed behavior. A wonderful example of this would be the [Pioneer Anomaly](http://en.wikipedia.org/wiki/Pioneer_anomaly). Currently we think this anomaly is explained by the radiation pressure exerted by the RTG. The observed effects is within the error bounds expected of this radiation pressure. But for someone looking for story ideas, imagine that later refinements indicated this either does not explain the effect or only explains part of it. We might be seeing a rounding error. For story purposes, this could lead to a general search for other such phenomena in cases in which we are capable of extremely precise measurements. **Hacking the Universe** As for hacking the Universe... The Universe would be the most complicated program that we could imagine (or perhaps more complicated than we can imagine). Such an unbelievably large body of code would be certain to contain errors. As someone above mentioned, use the "Stack overflow" approach or other methods that make use of flaws in the code. It might take a while to find one... Greg Bear's novels [The Forge of God and Anvil of the Stars](http://en.wikipedia.org/wiki/The_Forge_of_God) posits the ability to "write" into the registers of matter to change it. If a method of doing so was ever discovered, we could easily write to the registers giving location, etc. We could instantly teleport to anywhere or use it to change mass / momentum to objects enabling us to achieve any desired acceleration or velocity. Jack Chalker's [Well World](http://en.wikipedia.org/wiki/Well_World_series) series showed it took a super computer the size of a small moon to hack the simulator code to get the desired effects. If we were successful in hacking the Universe simulation and gained access to the "OS" level, we could conceivable chat with other simulations running on the same "system". Alternatively, we could change our simulation or run others. **Philosophical Questions** Philosophical twists I haven't seen here: Simulations are run for a reason. In my case, I ran a simulation to solve problems. What problem is our simulation solving? Maybe other simulations are solving other problems. If we had access to their simulations, what might that do to solve our problems? What happens when the creators discover that we've hacked their simulation and are no longer solving their problem? Or that we're also hacking their other simulations and polluting their system? What happens if we develop a [Taylor Algorithms](http://en.wikipedia.org/wiki/Eternity_%28novel%29#Taylor_algorithms) pass them up to our creators and they discover they too are simulations? [Answer] Digital Physics posits that our universe is a computational device. More precisely it says that our universe is mathematically isomorphic to a universal Turing machine. These theories state that our universe evolves from one state to the next in a way which is *isomorphic* to applying a finite number of simple rules for manipulating 1's and 0's. (A Turing machine actually uses seven rules, but there are equivalent formulations using fewer.) Physical phenomena are described by the informational content of *bit strings*. For example, flipping a few bits from a 1 to a 0 may describe the ionization of an atom. The occurrence of a bug would mean that our universe would find itself in a state that is not *computationally consistent* with its previous state. In other words, its state does not follow from the correct application of the rules. Had the rules been applied correctly, then the universe would be different. Assuming such a computational error is possible, the possible outcomes would range from the trivial, transient, self-correcting type of error, right up to the fatal, catastrophic, world ending type of event. For example, if a few bits flipped causing an electron's charge to change from negative to positive just before it fell into a black hole, then it probably wouldn't matter much. On the other hand, if the value of one of nature's fundamental constants was overwritten, then the effects would probably be catastrophic. For example, flip a few bits in the value of the strong nuclear force and we might see all atoms lose their coherence as their nuclei fell apart. Somewhere in between, a bug would most likely manifest as a paradoxical state of affairs. Perhaps something like two different objects appearing to occupy the same volume of space, or some sort of localized infinite loop. If the program included error-correcting code, then any paradoxical behaviour would be localized and "removed from view" (computationally excluded), so that we could see whole galaxies vanish should a serious error arise. Indeed, localizing and removing from view is precisely what a black hole does. [Answer] This is almost too short to be an answer, but I cannot help but channel the mind of a great Science Fiction author. Remember, we're looking at what the bug would look like from a perspective inside the universe. In the words of the great Isaac Asimov: > > The most exciting phrase to hear in science, the one that heralds new > discoveries, is not 'Eureka!' but 'That's funny...' > > > [Answer] One quite nasty type of bug (which can especially be hard to find, and can give quite inconsistent results) is out-of-range indices, in a language which doesn't range-check indices (likely to be used in simulations because range-checks cost valuable computing time, and do nothing useful if your code is correct). An out of range index ultimately means that values are read or written in a place where they should not have been read or written; this place may be completely unrelated to the place where the data is meant to go. Indeed, the infamous buffer overrun is a special case of out-of.range indices. Inside the simulation, such out-of-range indices could for example manifest as strange influences between completely unrelated events (because the out-or-range read ready data belonging to the other event, or the out-of-range write alters data belonging to the other event). Such influences could violate otherwise strict laws (for example, they could easily result in faster-than-light effects, if the erroneously accessed memory belongs to a far away event — after all, far away in spacetime doesn't need top mean far away in computer memory). Similar effects could be caused by reads of uninitialized variables which happen to contain unrelated data belonging to a different point in space. Finally, while not really a bug, also bit flips in memory (caused e.g. by — real, not simulated — cosmic ray particles crossing the memory chip and altering the charge of a memory cell) might cause quite interesting effects in the simulation. Such events would be rare (but if the simulation runs quite slowly and the computer uses non-EEC memory, it might be not that rare if measured in *simulated* time). Since bit flips can also cause rather large differences in values, this would give random events that may well be measurable in-simulation (but of course would not be predictable; after all, they are not even predictable in the "outer" world). [Answer] Surprised that no-one has mentioned quantum observable differences. In a computer game, when the view screen is not being rendered (because the player is not looking in that direction) the graphics 'dumb down' to produce the results of whats going on, without needing to render each pixel correctly, because its cheaper computationally. In older games you can see this in distant objects being rendered poorly. In Quantum physics, when particles are fired at a slit and watched by an observer, they fire individual particles which obey particle physics laws, yet when no observer is present (including cameras) they obey wave form physics, which would be a far cheaper computational result. So, it could be considered a bug, that the 'results' of the particle firer can be viewed with two different results, based on if an observer is present or not. until a civilisation invents technology to observe particles, no-one would know. [Answer] As I brought up in a prevous *hacking the universe* topic, perhaps anyntime an error is detected then the state is rolled back, as a cancelled transaction or restore from backup. It would make any bugs or hacking attemps unobservable. Perhaps it can be detected by what doesn't happen, as it avoids the bugs. [Answer] There have been [jokes](https://www.reddit.com/r/Futurology/comments/50eh6e/an_independent_scientist_has_confirmed_that_the/d73o9h2) recently that the way the RF resonant cavity thruster (known as the EMDrive) works, are a recently discovered [rounding error](https://en.wikipedia.org/wiki/Round-off_error) to our universe. We see rounding errors in computers often. To quote the reddit user NoHahForACrudite, in explaining this universe bug: > > Basically, when something is accelerating (speeding up in one > direction or changing direction at the same or higher forward > velocity), in it's [sic] own frame of reference, it will get warmer. This > change in warmth is (in simplified terms) "blackbody radiation". The > longer the wavelength of BBR, the "cooler" the radiation. What the > article seems to be saying is that because the acceleration imparted > by the microwave radiation is so immeasurably small, and because the > wavelength of heat it would generate would be physically impossible in > this universe, instead of that acceleration being expressed as an > increase in warmth (BBR), it becomes "quantized" as a change in the > object's inertia (the object gains "movement"/"push" in a certain > direction). Ostensibly, doing this at a high frequency would manifest > a measurable change in inertia/acceleration. > > > [Answer] You can clearly see geometric artifacts from the texture mapping on the top of Saturn (the designers never intended us to look there): [![Saturn artifact](https://i.stack.imgur.com/IPbKN.jpg)](https://i.stack.imgur.com/IPbKN.jpg) [Answer] It's possible the universe is bug free or our view of the universe is unable to detect bugs because it has a checksum in place to detect errors which may have been introduced during data transmission and storage. Ya that sounds weird, but here is a complex high energy physics paper on the subject: <http://arxiv.org/abs/0806.0051> [Answer] There could be something like an off-by-one error, that accidentally leads to there being more matter than antimatter. [Answer] A crash bug would look like universe ending abruptly for no reason, so I guess it wouldn't look like anything to us since our ability to perceive the bug would disappear as soon as it happens. Other kinds of bugs can cause almost anything: missing textures, objects being too large or too small or not there or in a wrong spot. Colours can get screwed up, sound disappearing. Repetitions are possible, though they wo [Answer] ## Mandela Effect This is something some people actually believe in. The Mandela Effect refers to a phenomenon in which a large number of people share false memories of past events. It was named after Nelson Mandela, whom some people erroneously believed to have died in prison in the 1980s. The explanation could be the answer to the question: we live in a simulated world and the Mandela Effect is just a bug, like a hard drive corrupted memory. There are many examples in the internet, here the most popular: * C-3PO from Star Wars was gold, actually one of his legs is silver. * Queen in Snow White says, “Mirror, mirror on the wall”.The correct phrase is “magic mirror on the wall”. * Berenstein Bears instead Berenstain Bears * looney toons instead looney tunes [Answer] # Odd interactions with itself My take on this is: how different parts of the program relate or react to each other. Somethings that works well separately don't work "right" together. Sodium is a highly reactive substance that has a tendency to kill things in it's free state. Chlorine is also a highly reactive substance that has a tendency to kill things in it's free state. Put them together, and we have an extremely stable salt that is a requirement for many life forms. Mercury is a highly stable element. So is gold, and happens to be normally solid at "room temperature". Add gold to a puddle of mercury, and the mercury dissolves the solid gold. # Radioactivity Radioactivity is parts of atoms that fly away from itself at random times, for not necessarily reasonable reasons. This screams "bug" to me. It doesn't matter if we (think we) know why is does this, it just doesn't act like most other parts of the program. This is more of a buffer overflow issue. Atoms become too large and there just isn't enough room to hold the data. The array just doesn't have enough memory allocated, we just don't know how to ReDim the situation yet. (Sorry, I couldn't resist. I should have, though.) On the another hand, maybe there isn't a routine that can take that many parameters. # Take away We use science to come up with reasons, rules, laws, and guesses as to why things work like they do, but that's the wrong aspect to take when writing a program. Science is documentation of the current features, not a plan for what the program "should" be doing. Unfortunately, the program is "in the wild", and users are dealing with work-arounds. Some of them even like the work-arounds and make them work for their needs. The programmers are afraid for their job, so they aren't going to admit that there are any bugs. They know how fragile the code is, and making a change in one area might have unintended consequences in another area. No users are submitting bugs, so it's fine. Prayers go to an unmonitored email account, or the account was entered incorrectly, so the form isn't actually sent, even though it looks like it did. There's no error logging, so no way for the programmers to know the users are having issues. [Answer] From the perspective of my own comprehension I find time, particularly in the relativistic sense, very hard to grasp. Conceptually difficult areas are a ripe breeding ground for bugs and undefined behaviours in code because you can only model based on your understanding. Consequently if I were worldbuilding for this type of setting I might look at some time-related problems. Let us imagine for a moment that something tangible could - thanks to a bug in the temporal system - pass between two disconnected points in time. So you might get a little light from a past - or future - event passing into any given present. A witness to this event might see a vague image of a person in old fashioned clothes going about their daily activity or perhaps they see the form of some distant future flying machine pass over in the sky. The light may well only escape in a specific direction, so something may be visible from one place but not others. Other tangible effects could also arise - unexplained scents, sounds, cold spots in the air and so on. So things like ghost and UFO sightings could be explained as errors in the spacetime implementation of a universal simulation, allowing you to take that ghost story into some less predictable directions. [Answer] Simulating a universe in universe itself can only by done on a higher abstraction level striping it of its actuallity. A simulation of the entire universe can only be the universe itself. Some of the accidentals of the universe exists probably only in universe itself like the categories of time and space. Some laws of nature may be valid only local. Gödel's incompleteness theorems: "The theorems are widely, but not universally, interpreted as showing that Hilbert's program to find a complete and consistent set of axioms for all mathematics is impossible." [Wikipedia Gödel's incompleteness theorems](https://en.wikipedia.org/wiki/G%C3%B6del%27s_incompleteness_theorems) [Answer] ## An explosion, a black hole, or false vacuum collapse (This answer assumes that physics works as we perceive it, and that the program does not "cheat" and store large objects independently when we are not looking at them. If macroscopic objects *are* stored directly in the program, then none of this applies.) Since the "base code" of our universe appears to operate on a subatomic level, with all macroscopic objects being emergent properties of those subatomic events, it seems unlikely that macroscopic objects such as buildings or cats would experience noticeable changes that maintained their overall structure, since "building" and "cat" are not actually encoded objects, but structures formed out of encoded objects. A bug that affected the entire simulation would simply end the universe and would therefore not "look" like anything. The devs would likely fix the bug and then, if they were able, reboot from the last clean save. The only kind of bug that might go unnoticed or unpatched by the developers (and therefore, noticeable by us) is something that changes a fundamental value of a single particle or region of space. Most of these bugs would go unnoticed by us as well, *unless* that value was changed *a lot* from its expected amount. Maybe a single particle spontaneously gains the mass-energy equivalent of a planet, or accelerates to within a trillionth of the speed of light. This could result in one of several possible results. If the value was changed to a high but reasonable level, it would result in an explosion of energy. This explosion could range from anywhere to a tiny pop of heat and light all the way up to supernova levels. If the particle's mass-energy equivalent was high enough, it might also generate a black hole. A small enough black hole would quickly explode. A larger one, if it appeared on Earth, would fall into the planet and consume it from the inside out. Looking in space, we *might* be able to tell the difference between a black hole that appeared naturally and one that appeared spontaneously, but unless we were looking at it as it appeared this is unlikely. New black holes are generally surrounded by the exploded remains of the star that produced them, but old black holes would be virtually indistinguishable from spontaneously-generated ones. If the energy of a region of space fell *below* the base energy level, or "zero point", the results would be even more catastrophic. This would create an unstoppable chain reaction that spread out through a spherical region at the speed of light, destroying everything in its path. This phenomenon is known as "false vacuum collapse" and if it were to happen, it might destroy the entire universe (eventually). If the devs managed to hotpatch this without resetting the entire simulation by simply deleting everything within the spherical region, and they did not recreate the destroyed space accurately, we might notice the result. Perhaps a spherical chunk of space would simply be devoid of stars, or the stars in it might shift around, or we might be looking at the aftermath of such a bug millions of years after the patch and notice that the stars from this region are not moving at the speed they should be relative to the space around them. [Answer] The Random Number Gods Really Would Hate Us! No, seriously, RNG aren't truly "Random" They are at best Psuedo-Random and can be pulled from a list with a seed or key in the same order for the same key. This was used in a Doctor Who episode as the give away to this exact problem. Our "Heroes" were really just models in a hyper-realistic simulation of the world but the RNG for the human response to the prompt "Pick a Random Number" was not properly seeded for each human resulting in every answer of the question in voluntarily follow the same values in the same order. This is an easy mistake to make in coding, and is only detected on multiple runs of the same code as the RNG unseeded will produce the same list of values in the same order in all iterations. [Answer] In one of the Matrix movies, they mention that all the UFO and ghost sightings are glitches in the Matrix. Deja Vus are also seen as glitches, but they mainly happen when someone changes something. A few other things that I could see as glitches in reality: * Missing Socks. * Hawking Radiation. * Quantum Tunneling. * Special Relativity's slowing of time near the speed of light. * Dark Matter. [Answer] Presence of a bug in a computer program means that all results are according to our expectations but under certain condition, the program gives unexpected results and behaves in unintended ways. Bugs in a simulated world can cause fatal effects. In 1973 movie 'Westworld', the human like androids get bugs in their programs and as a result, many humans die. In the universe, objects are following certain laws (Kepler's laws of planetary motion, Maxwell's equations, Relativity, Gravity etc.). When a bug is encountered, some law will be broken and some objects will behave in unexpected ways (could be fatal). [Answer] Just wanted to channel the Stalker SF video game series because I see that something like this hasn't been mentioned. In the game, due to Chernobyl and other experiments there are areas near the disaster site where the rules of physics have been corrupted. They are called [anomalies](https://stalker.fandom.com/wiki/Anomaly). This is less physicsy than other answers but could still work. Perhaps it's due to a buffering error or something you can get these anomalies. ]
[Question] [ As we all know, language in England has changed massively over the centuries. How far back would someone be able to travel in time and still have a basic understanding of what most people are saying? The person going back in time is around 30 years old, only speaks English, and is located in the north of England. [Answer] It's a lot more complicated than it sounds. Not just for the fact that the language changed considerably over time, but because it is highly dependent on in which circles you commune. The higher the educational background, the less trouble someone from 'modern day educated London' would have understanding early modern English (what we know as 'Shakespearean English'). However, that only accounts for anything after the year 1450, give or take. And that, again, depends on in which circles you enter. As an example (taken from <http://www.bardweb.net/language.html>): Time Period Example: The Lord's Prayer > > **Old English** 450–1066 Fæder ure þu þe eart on heofonum; Si þin nama gehalgod to becume þin rice gewurþe ðin willa on eorðan swa swa on > heofonum. > > > **Middle English** 1066–1450 Oure fadir that art in heuenes, halewid be thi name; thi kyndoom come to; be thi wille don in erthe as in > heuene. > > > **Early Modern English** 1450–1690 Our father which art in heauen, hallowed be thy name. Thy kingdome come. Thy will be done, in earth, > as it is in heauen. > > > **Modern English** 1690–Present: Our Father, who art in heaven, Hallowed be thy Name. Thy kingdom come. Thy will be done, On earth as > it is in heaven. > > > And this is just in the 'mainstream English' of the time periods. Don't dare negate dialects thereof, lack of education meaning worse pronunciation thereof, and the simple fact that because of geographic isolation, many 'sub-dialect/languages' would spring up every 50 miles. This is why people from England/UK can identify where someone comes from just by talking to them, and that's these days with a 'unified education system'. How much more pronounced would this be in the time period you aim for? Let alone the implications of the era you aim for. There's still serfdom/slavery to consider if you go back to the Medieval days, and that is also heavily dependent on which period as well. This is important to language, because if you go back to slavery days, that means the society would be importing slaves (England refused to sell their slaves outside of England, therefore there was only an influx of slaves) which means there would still be those that have odd accents, depending on how accurate you want to portray the scene. [Answer] [This documentary](https://www.youtube.com/watch?v=upKqzxuJ5L4) is an interesting look at a [preserved dialect](http://wamu.org/news/11/06/27/tangier_islanders_retain_unique_dialect.php). Can you understand it? You can also look at literature as a guide post, especially lit with conversation. There are some places here in the USA where you can barely understand people, because the dialect is so specific (Virginia, parts of Louisiana). [The Secret Garden](http://read.gov/books/secret-garden.html) set in Victorian times, has some very interesting language, and the MC at first has a bit of trouble understanding the native talk. The further back in time you go, the more likely communities will be isolated. That isolation contributes to a different manner of speech, words used that aren't standard, that kind of thing. Without a standardized school system and mass media even communities that speak the same language will have specialized dialects. Something you might want to listen to: [Beowulf](https://www.youtube.com/watch?v=_K13GJkGvDw). Yes, that's English. Really old English from about one thousand years ago. I think that's pretty incomprehensible for most people. Shakespearean dialect is covered [in this video](https://www.youtube.com/watch?v=gPlpphT7n9s) at about 2:40 they start showing the difference, which isn't bad and is certainly understandable. That's about 1600. Language changed drastically during this time. I'd say 1600 is about as far back as I'd go, maybe 1500, because that's when our language started to become more modern. I think the [1300s](https://en.wikipedia.org/wiki/Middle_English) have more in common with the 900s and 1000s than it does with the 1500s. That's where I would cut it off, as far as comprehensibility is concerned. Choose your time period and then research not just the language of the time, but the language in that specific place. [Answer] Well, there's a lot of dialects of English today (such as in parts of Britain and Australia, and "street" slangs common in many urban areas) that are unintelligible to the bulk of anglophones. It depends on several factors. * Whether the conversation is written or spoken. Written doesn't have phonological issues (although orthography may be different) but is also fundamentally different in nature. * How motivated the speaker is to be understood. For instance, if the modern speaker ends up dealing with a bunch common criminals from 1800s London, not only will they have little motivation to speak in a way that is easier to understand, but they might deliberately overuse their slang so that the time traveler is revealed as someone "not from this part of town". * The education level and social class of either party. Obviously a professor of English literature will have more luck, but depending on time or place, the upper or lower classes may have a particularly confusing manner of speech. Once again, recall that our 30 year old Englishman (let's call him Bob) could find himself in many conversations *today* where he would have no idea what's going on: Technical discussions between professionals, criminal slangs, various dialects and so on. But while it would be difficult for Bob to conceal that he's an outsider, if the other person is helpful it should be rare that they can't find a way to communicate (eg. speaking more clearly, slowly, without slang or in a more neutral accent). ## Mid-20th century onwards Up to roughly the 50s-60s, this situation remains the same. From various recordings, film, documentaries and other such primary sources, it seems like mainstream English underwent little substantial change. The accents may be a bit different, obnoxious teenagers may say "groovy" instead of "epic", but they pretty much talk in the same way. Possibly this has to do with the spread of TV, which established a sort of "common denominator" way of speaking for most of the anglosphere. After being amused by the trivial differences for a few weeks, Bob would get used to it and communicate without difficulty, and after a few months he could probably easily "pass" for a non-time traveler. ## Early 1900s WW1-WW2 seems like a period when spoken English begins to differ perceptibly. TV had not yet began to dominate culture, so regional and subculture-specific idiosyncrasies were common. In video, audio, and books written in an "everyday" language (either for effect or because the author was uneducated) begin to sound "quaint", and often feature expressions that seem confusing. Bob would be able to communicate with most people from Day 1, but he would frequently be confused about this or that subtlety of meaning. It would be a while before he doesn't have to say "Sorry but what do you mean by..." about commonplace words and expressions multiple times per conversation. It would be a long time before he can learn to "pass". Written English would be much easier, as evidenced by books, pamphlets and signs from this period, except for the occasional euphemism-du-jour which has since fallen out of fashion. The two world wars are handy delimiters, but I would say that this period was only really succeeded in the 50s (and maybe even 60s), and the preceding period ended several years before WW1 began. ## 19th century From roughly the first third (give or take 50 years, depending on time, place and other factors) of the 19th century up to WW1, I think the non-trivial unintelligibility starts. Beyond just *I got the gist of what you're saying but I'm not sure what exactly that one remark meant*, we are getting into frequent *I have no idea what the hell you just said* territory for at least the first few days, especially with less educated people from lower classes. Texts from this time are basically intelligible to modern readers, but it is clear that a fair bit of unintelligibility is lost in transcription, if you will. For instance, consider novels which try to render authentic every day speech, such as some of my Mark Twain's works. I'd conjecture that the period is associated with the Industrial Revolution, the dominance of the British Empire, and the advent of the Prussian education system (which is ubiquitous to this day). ## Age of enlightenment(ish) In early 1800s, 1700s, and maybe late 1600s we get written works (even on complex topics like philosophy, history, religion and science) that are pretty much intelligible, but sometimes effortful reading much helped by a good dictionary. Bob could, at worst, carry around a pad and communicate by writing, assuming he can find someone literate: we are now just before public education became common, and coincidentally literacy rates are shockingly low. Alternatively, he could attempt to speak like he would write, but there are still large differences in pronunciation, vocabulary and what is considered idiomatic. He would struggle to introduce himself to the first person he meets. If the person has some complex concerns (eg. a guardsman on the lookout for spies) I don't think he could resolve the situation diplomatically by the end of the day. If it's not weeks before he stops feeling like he doesn't even speak the same language, he should consider himself lucky. It might be a year or more until Bob is "fluent", and 5-10 years before he can pass. Once this process is complete, if he returns to his own time, he will experience a similar culture shock for several months to a couple of years. ## Middle ages Early Modern English, from which our current language evolved, was prominent from 1400s to late 1600s. During this time, English went from its pre-15th century form, which is unintelligible to modern speakers, to what we have now. We conveniently have Shakespeare's works, among many others, to demonstrate the nature of EME: It is very obviously on the cusp of being an entirely foreign language in all but name. Even written material is difficult to understand unabridged. An educated reader (even if the education includes reading Shakespeare!) can understand a fair bit of Shakespeare's writing, but there will still be a significant chunk which is hopelessly opaque: Too many words are simply not used anymore, or mean entirely different things. Without a glossary, it would be a tremendous effort to decipher them. We have no way of knowing exactly how people spoke day to day around this time. However, it's likely [very different](https://youtu.be/dQvD2Hj-Odc). Unlike the period above, you now have a vicious circle sabotaging any efforts at communication: Ordinarily, you would segment speech into words and then try to figure out the unfamiliar ones, but the pronunciation is too unfamiliar for that. Yet you can't figure out the pronunciation either, since you don't know what the words are and can't effectively look for them in the sentence! Bob is two thirds of the way to learning a whole different (but similar) language, like French. The vocabulary is different (even though a lot of words are the same, or at least [about the same](https://en.wikipedia.org/wiki/False_friend)), the phonology is different, it's only the grammar that is mostly the same. How much does it take for Bob to become fluent in French? Let's say 6 years with instruction, well, call it 4 for EME. Of course, that is with instruction... The key event here is probably the printing press, which began spreading around England in the 1400s. Note, also, that only towards the end of this period did English start spreading to areas of the world (America) outside of Britain proper. ## Early middle ages We are now firmly on the other side of the hump and into "it might as well be a foreign country" area. A good, familiar example of this is Chaucer's writing. Bob can't read it. He literally can't even read the script. If it was put into a modern font (something impossible without professional help), he would not understand the words. If it was [spoken](https://youtu.be/B5QAV6lOCnQ) it would sound like gibberish. Considering the various social aspects of this period, I would seriously doubt Bob's long-term survival. He could easily get killed, imprisoned, or otherwise get [into a lot of trouble](https://en.wikipedia.org/wiki/The_Man_Who_Came_Early) due to inevitable misunderstandings and miscommunications. If you have Bob *ever* managing to communicate with anyone, such as after years of trial and error, you have to invoke a stroke of luck soon after his arrival, such as a [kindly benefactor who supports him for many months](https://en.wikipedia.org/wiki/Sh%C5%8Dgun_(novel)) when he is unable to function in society. The key event is the Norman Invasion in 1066, which is when a bunch of Frenchmen invaded Britain, put themselves in charge, and didn't even bother speaking proper English. ## The dark ages Remember how I compared learning early English to learning French? If Bob arrives prior to the Norman Conquest, it might actually be [harder](https://youtu.be/_K13GJkGvDw). I would say that difficulty is comparable to learning a Nordic language, such as Norwegian, today. I doubt Bob would do any better than Hans or Xavier if he went this far back. The key event here is the Roman conquest of Britain, and the spread of Christianity: Both provided a host of Latin words and influence, which produces a fair bit of common ground for modern speakers to discover. However, if you go farther than that, just give up on having any intelligibility whatsoever. As far as 500 BC, I suspect it won't make much difference to Bob whether he arrives in the British Isles or China. *Good luck, Bob! Wouldn't wanna be in your shoes!* --- NB: The periods I give above are very approximate. I tried to note what historical events strongly influence the change in language, but ultimately different parts of the world were undergoing the change at different rates, as were different strata of society. [Answer] **1066~1440 CE** before the [normans conquered england](https://en.wikipedia.org/wiki/Norman_conquest_of_England) in 1066-1072ce, the residents of england spoke a language called "old english", which is arguably more similar to modern german than modern english (e.g. [Beowulf](https://en.wikipedia.org/wiki/Beowulf) 700~1050ce). so, before 1066 you would have almost no chance of understanding anyone without significant study. after the normans conquered england, the conqueror's "old french" mixed with the commoner's "old english" to form a new simpler language we today call "english". that said, it took a few generations for the languages to mix, so in 1073 you would be just about as lost as 1065, but by 1300's things would start sounding familiar (e.g. [the canterbury tales](https://en.wikipedia.org/wiki/The_Canterbury_Tales) from 1386). still, without modern printing, dialects varied widely between towns, classes and generations. in fact, a typical uneducated serf would have a gruff german vocabulary you would consider rudimentary, while an "old money" noble conversation would sound closer to french and might actually include a few french or latin words. it wasn't until the [printing press](https://en.wikipedia.org/wiki/Printing_press) was invented in 1440 that the english language started to unify and stabilize into what we would recognize as "modern english" (e.g. [asop's fables](http://www.bl.uk/collection-items/aesops-fables-printed-by-william-caxton-1484) from 1484, typeface notwithstanding). so, listening to an educated person speak in 1450 london would be almost perfectly intelligible. you might need a few days to get used to their accent, word choice and world view, but the vocabulary and grammar would be perfectly serviceable to discuss most topics. futher reading: <https://en.wikipedia.org/wiki/Middle_English_creole_hypothesis> side notes: you must keep in mind that the culture of pre-modern england was very different from today. on the one hand, without mass transportation, most people lived their entire lives within 40km of their home. with no dictionaries, they expected to have difficulty communicating with anyone who lived more than one village away. as such, they would probably be more adept at bridging the dialect gap than you. in a big city like london, you could probably find someone you could understand quickly. on the other hand, rural strangercide was much more common, and they might just kill you rather than try to figure out why you left your previous home (presumably not by choice...). at the very least, once the local lord determined you did not belong to any other lord, he would probably try to force you to work his land rather than accept the preposterous premise that your knowledge could be more valuable than your muscles. even today, you can see the upper/lower class french/german split in distinctions like a restaurant's "beef" (french bœuf) vs a farmer's "cow" (german kuh). or lower class german expressions like "blow up" vs upper class terminology such as "explode". [Answer] To answer in a more simple way than the other answers which are all fairly good... There are places today that if I dropped you in the middle of as an English speaker would have no clue what the other party is saying even though you are both speaking English, such as the stereotypical Scotsman, or someone using Cockney rhyming slang. So the answer to your question is 0 far back and just move you to a different place. As far as going back as far as possibly till you can't understand anymore. That's highly variable and depends on what is being said and how good your character is at figuring things out. "What's up, my brother?" "Wassup, my brudda?" These are modern english and understandable. Changes happen at a rough pace of 1 sweeping change every 30 years it seems to me, so let's say we move you 100 years in the future... "Wassub, my brotta?" "Wazzup, my blutta?" You can still understand that, but what if used another variation... "'Sup, m'brother?" in 100 years using the same alterations as before... "Sub, m'brotta?" "Zup, m'blutta?" Do you think you'd be able to understand that? But I'm sure you'd understand.. "This is m'brotta n sista" "Thiz iz m'blutta n zizta" Now if you went for 500 years, it is likely that any changes that happened in that 500 years isn't going to change again. For example s => z happens so that z seems to be safe till the next 500 year cycle. So really the question is when you apply around 15 changes to the most common words in the language how long is it before you haven't got a clue? I imagine 3 or 4 jumps before they mostly look like a scrambled mess. So I'd place it around the 500 CE mark where things start becoming fully incomprehensible, but for the average person I'd expect 1500 CE, maybe a little bit further back. Just read Shakespeare as it was written and see how much trouble you have understanding it. That was written for the masses, so if you can't understand it, you're likely not able to understand 500 years ago. [Answer] It is going to depend primarily on the size of the person's vocabulary and their ear for accents. Go read some snippets of Shakespeare and Chaucer. Someone who is familiar with the second, third, and fourth meanings of the words they know, and who has a large vocabulary will have the ability to understand anything later than Old English with a little effort. The words in common usage have changed, but are still largely recognized with their original meanings. The pronunciations have changed a bit over the centuries as well, but in a more-or-less regular pattern, so it's not much worse than understanding someone with a heavy accent. Read some of Shakespeare's sonnets and soliloquies, keeping in mind that they many are supposed to rhyme and have a particular syllable stress pattern. You can use the rhyme and pattern to figure out how the original performer would have pronounced the words. (What's more, you'll notice that the different characters have different accents depending on social class and origin; Shakespeare really was a master playwright, but I digress.) Mastering the local idiom will take some effort, but that's true even of modern English. Slang has a lot of variation from place to place. Once it switches over to Old English, you're in an entirely different boat. Grab a copy of Beowulf and a pronunciation guide and try reading some of it aloud. Some words are recognizable, particularly the ones for important concepts. But the common pronouns and tenses are almost all different. The last time I tried to sort it out, I couldn't recognize more than about 20% of the words and phrases, and that was with a literal translation available to make some of the patterns more clear. The language is similar enough for total immersion to probably cut the learning time for a well-educated speaker down to a few months instead of a few years, but that's about all you get. On the other end of the spectrum, the average "publik skool gradyouate" these days probably doesn't have a sufficiently large vocabulary to hold an intelligent conversation with anyone from more than about 150 years ago at best. The words are all still English, but the most commonly used terms for things has shifted radically in some areas. "Gramophone" instead of "record player" for example. How many are a "score"? What body part is the "gob"? A lot of scientific terms had yet to be standardized, as did a lot of word spellings. You can find old journals, diaries and political speeches on the web to use for comparison. [Answer] As a starting point: there are still English accents around even today, inside England, with which some native English speakers have a fair bit of difficulty. This is alleviated by "received pronunciation" a.k.a "BBC English" or "Home counties English". Basically, everyone listens to the TV and radio, and learns to understand that accent, and to a greater or lesser extent to shift their pronunciation towards RP if they are talking to someone from way out of town. Also drop any dialect words in favour of the standard ones, in the same way that I will substitute sidewalk for pavement and so on when I'm in the USA. (This is assuming a desire to converse ... a good way of persuading strangers to go away is to remain resolutely incomprehensible! ) It seems to be quite idiosyncratic as to who has trouble with which accent. Personally, I find Glaswegian the hardest. (OK, Glasgow is in Scotland, but the vocabulary is English, and other Scots don't baffle me as long as they're not speaking Gaelic). A friend has real trouble with Devon accents. I have none at all. Anyway, go back a couple of centuries, and there was no Radio and TV, so no nationally standardized received pronunciation, and no railways so visitors from a couple of hundred miles away were rare. I expect that this resulted in a greater diversity of regional variations. So I expect that at first hearing, you might be unable to communicate. On the other hand, again assuming a desire to converse, you would probably recognise that you were hearing English spoken with a strong accent (as opposed to, say, Dutch), and adjust, and learn quite rapidly. As a recent example of this process, a relative (from London) went to University in Liverpool where she shared a flat with some locals. After a term away, her accent had shifted very considerably North-West, and when she came back home it took a week or so of hilarity before her London accent reasserted itself. The question is unanswerable: "travel in time and have a basic understanding of what most people are *saying*". We can see that Shakespeare's English has vocabulary and grammar that is fairly accessible to a modern *reader* of English, and that Chaucer is much less so. However, we cannot listen to English as was spoken in a particular time and place centuries ago. I expect three of four centuries back in London would be far more challenging than three or four hundred miles into a rural community with a strong local accent today. I also suspect that it would be far less of a mountain to climb, than trying to learn Dutch without any textbooks or conveniently bilingual Dutchmen. (Dutch chosen because it's probably closer to the Anglo-Saxon roots of English than other European languages.) Edit: RP itself evolves quite fast enough to notice and grate upon those more than half a century old. Recently seen in "the Telegraph", a letter requesting that BBC commentators cease pronouncing athletes as ath-uh-letes I hadn't noticed, until I read that, and now it's also grating on me! [Answer] A key point was the advent of printing, especially printing with movable type. This made text a lot cheaper to produce and so there was more of an incentive for people to become literate which naturally tends to standardise language as texts are disseminated more widely. At this point it is also worth noting that through much of the period when English was developing Latin and Greek were the standard languages for academia and theology. Note that [Isaac Newton's Principia](https://en.wikipedia.org/wiki/Philosophi%C3%A6_Naturalis_Principia_Mathematica), one of the first texts to be generally recognised as science in the modern sense was originally published in Latin. Similarity the use of Latin rather than 'Vulgate' languages (such as English) was one of the major issues of the Reformation, note [Martin Luther's translation of the Bible into German](https://en.wikipedia.org/wiki/Luther_Bible) in 1522 (with Tyndale's translation into English not long afterwards). Religion was important because it was the one universal context in which people at this time had with the written word (albeit mediated by priests) and translating the Bible and Church liturgy into English meant that it was something which people could understand rather than just being exotic mystical words. The Anglican [Book of Common Prayer](https://en.wikipedia.org/wiki/Book_of_Common_Prayer), printed in English and widely distributed is also widely accredited as a major milestone in the establishment of modern English as it Dr Johnson's famous Dictionary. As others have mentioned a crucial aspect of this is that standardisation was hugely important in establishing modern English as a distinct language and before that there were many regional dialects which were often hybrids of several layers of languages from various periods of settlement and conquest, which can be seen from place names. Even now there are areas, especially in the north east, west midlands and Scotland where there is still a residue of very strong regional dialects, which go much further than just accent or slang, which can be virtually incomprehensible at times to non-locals. So to directly address the question it seems fair to say that by around the early 1600's comprehensible modern English was well on its way, for example the works of Shakespeare are mostly comprehensible to modern speakers, especially considering that he was writing in quite a stylised form and most of the differences are vocabulary rather than grammar. So we can say with some confidence that by the 1600s a recognisable form of modern English was in reasonably wide circulation. Indeed Shakespeare himself was a middle class midlander rather than part of the academic, political or religious elite. Going back much further than that we encounter the problem that we have less evident to go on as written or printed texts tend not to reflect a wide section of the populous. We can say though that works like the Canterbury Tales (1386) are pretty hard going, especially with the original spelling. [Le Morte d'Arthur](https://en.wikipedia.org/wiki/Le_Morte_d%27Arthur)(1485) is interesting in this context. The original is clearly significantly different from modern English but this is mostly about how spelling is rendered phonetically and versions with modern spelling are reasonably comprehensible in terms of sense, although the writing style is incredibly dense and very hard work to work out what is going on with the story compared to a modern play or novel. By contrast if you look at something like Beowulf, the Eddas or Icelandic sagas, especially with an inline translation the way that the language actually functions in terms of sound, rhythm and conveying meaning isn't all that alien to a native English speaker, especially if you compare it to documents directly translated from say Chinese. ]
[Question] [ This is a medieval European (fantasy) setting, with the following (highly tentative) parameters: * Each town is vaguely autonomous, and have their own municipal government system. * Towns do trade with each other, but are not exactly dependent on said trade. * Towns vary in size from the rural village (pop. ~400) to a more prosperous city (pop. ~6000). * Town-vs-town warfare is historically rare and often not very substantial; any border control of towns would mostly focus on rogue bandits and the like. Given these parameters, what would be a feasible range of distances for towns to be separated by? [Answer] Distances between Medieval towns varied quite widely, as did the population and size. I think the estimate, and this is a low estimate, for England was that there were over 3,000 deserted Medieval villages that they hadn't discovered. Now, there are also going to be communities in between smaller than your 400 person population--groupings of families and trading posts along major roads. Also, not that many people would have lived IN some of these small places. Instead, there were a number of shop keepers, a tavern/inn, maybe a single guard and people who lived and worked inside the village, but for the most part, the population that you might see there would come from those coming in for the day to trade/buy/sell goods, who will later be going back to farmsteads within a day's walk. A town of, say 3,000 people actually would need about 10 villages and their surrounding farmsteads to support it. [SEE LINK](http://www.pensee.com/dunham/facts/braudel.html) This isn't just a straight line on a road with miles between. A large population place, such as a town or city with like 1,000 people, will actually be surrounded by "satellites" villages adjacent to these larger places. This happened in London--but as London grew, these communities were "eaten up" by the city itself by around the 1700 and 1800s. As to closeness, this rule about "a day's walk away" that people seem to be spouting all over the internet,--that goes right out the window. Many of these satellite villages would only be a mile or two away from their towns--or even less, some would be a scant 1/2 mile. They were not always on a main road, but they would be next to resources (such as water). Consider as well that some of these towns would be built around a particular thing--a mill for instance--a particular town might be a place where everyone from the surrounding communities come to get their wheat ground, or their leather cured, or something specific to that township. Not every town is going to have the same amenities, and that's important to remember when building them. Not every village is going to have an inn (though it might have people willing to rent a bed). A town of 3000 would have these 10 or so communities orbiting it--sort of the Medieval version of the suburbs, with a slice of country in between them. So when you were coming up on a real township, you might see more of these small communities, near the larger one--they'd be anywhere from 20 minutes away to 3 hours walk away (12 miles), to a few on the edges that might be as far away as a day's walk. An inn in a town such as this is going to be busy, because travellers just along the road, and traders--people also paid to bed up in barns and sheds nearby--or for a place to park their wagon for the eve. So your model actually needs to be built with the larger cities placed on the map first. Then, around each of them, place their satellite villages and settlements. Your max place of 6000--that will need maybe 20 little villages scattered around it. (Some of these won't have more than 50 people in them). Density and distance between can get weird and really really close in some places, especially when the "orbit" of two cities cross. In places where there aren't communities/cities of 1000 people to influence the placement of the smaller communities, the density gets lighter. So you might not see any villages for an entire day's walk or ride--this is why some enterprising fellows would set up an inn at a crossroads in the middle of nowhere. They knew people would be travelling, tired, and that there was no chance of anywhere (along the main road anyway) where one could rest, and feel somewhat secure (highwaymen are less likely to visit where there are people). These less dense places sort of make up for the areas where, every few miles, there's a village... Even your 400 person village is going to have smaller communities supporting it in this satellite configuration. These will be made up of substantially less people. As one of the other posters points out, 400 is pretty large. But let's take a mega-city of the time--London in the 1000s--population estimates are about 10,000-12,000. That means there are going to be about 40 communities surrounding it and supporting it, likely all within a 10 minute walk to about 3 days walk, because it's so large. By 1337, the London population had grown considerably. Here's an estimate of the population of largest cities from wikipedia, which I am adding because you've said your numbers are arbitrary, and it's good to have a basis: 1. London 23,314 2. York 7,248 3. Bristol 6,345 4. Coventry 4,817 5. Norwich 3,952 6. Lincoln 3,569 7. Salisbury 3,226 8. King's Lynn 3,217 9. Colchester 2,955 10. Boston 2,871 11. Beverley 2,663 12. Newcastle 2,647 13. Canterbury 2,574 14. Bury St Edmunds 2,445 15. Oxford 2,357 16. Gloucester 2,239 17. Leicester 2,101 18. Shrewsbury 2,083 19. Great Yarmouth 1,941 20. Hereford 1,903 21. Cambridge 1,902 22. Ely 1,772 23. Plymouth 1,700 24. Exeter 1,560 25. Hull 1,557 26. Worcester 1,557 27. Ipswich 1,507 28. Northampton 1,477 29. Nottingham 1447 30. Winchester 1,440 Keep in mind that there are lots of smaller communities surrounding each of these. A city of 6,000 would not be at all common by the standards of Medieval times. Just throwing out these numbers and specific cities to give you a base. Add to this that the low estimate of the number of Medieval villages that we HAVEN'T discovered yet is 3,000--and you'll see that the landscape was likely teeming with tiny villages along the way, with some less populated areas in between. As other posters have pointed out, the more farmable the land, the closer settlements are to one another. In the densest places it's going to be about one every mile or two (and there will be some very close to large cities). These communities are going to be tiny, but EVERYWHERE, with farmland in between. Please see the fantastic video in Giant Cow's answer--this distance is a pretty good yardstick for world-building (about 10 miles between each sizable town, which means that there's a town is within 5 miles for everyone) for places that are not as richly farmable, and less influenced by the larger cities. Medieval towns were different because of the factors I have outlined, often closer, much smaller, and with more distance in between settlements where farming was impossible or there was woodland. [Answer] This video explains why cities are were they are. You can apply this logic to the distance between towns <https://www.youtube.com/watch?v=3PWWtqfwacQ> Its worth pointing out that there is no standard distance between towns necessarily. Generally speaking, chains of towns can be seen along rivers at surprisingly even spacing (see the video), but these are all relative to one another. It is possible to have a city and surrounding towns be highly isolated. **The trick is to make a map and work backwards from it.** It will be obvious where to place cities. As the video explains, the expected distance for towns on a route is usually the distance you can travel there and back in a day. [Answer] Half a day's walk, little less. Perhaps a day's walk for the more remote villages. Given the average of 5km/h (3.1 mph) I'd say 25 kilometers, maybe 30 kilometers. Having half a day's walk allows you to go to the market of the city. Buy some things, sell some things and then still get home. So radiate villages outwards from the cities. Not neatly of course, the land dictates their exact location. This also gives you a good distance for inns. Set them about half a day from the village. Rivers might change this a bit, as going downstream might speed up your journey quite a bit. Depending on the location, if your people are blessed the average wind will blow against the current. That way you get either the current or the wind on most days. If I recall the Nile was such a river. I'd like to make a side note. Your estimate of a rural village being 400 seems a bit high to me. [Answer] There are reasonably accurate maps from the 1570s <https://upload.wikimedia.org/wikipedia/commons/3/36/Saxton%27s_Hampshire_1575.jpg> This one shows the county of Hampshire and each settlement. Most are clearly identifiable with modern villages towns and cities. On this map, it is apparent that few villages are more than about a mile or two from their nearest neighbour. In regions of better farmland, the villages are closer. They are more separated in the New Forest region, which is less suitable for agriculture. You can research further, as many of these locations can be found in the Domesday book. The population of England had changed between 1080 and 1570, but not by a very great amount (it had perhaps doubled), partly due to the effects of plague. Doubtless, some of these settlements are little more than farms, others are more substantial. However, each is a named location with an identity and a social structure. [Answer] In New England, especially rural Vermont, many towns are roughly 7 miles across with a town center centered. Driving Route 22a that is particularly obvious. Many of those towns were chartered in the 1600's, well before cars were in use, though they are certainly not medieval. I was told that the distance facilitated courting on Sunday afternoons. After church a young man would have the time and energy to walk to the next town, spend some time with a woman and her family and walk home. Also having the nearest town center no more than 3.5 to four miles away, i.e only about an hours' walk, makes going into town, doing something, and returning the same day a reasonable choice for regular events. I've tested this extensively. Outside of towns centers, houses tended to group into blocks about a mile apart. Off the main roads, this is still a common pattern. Open fields and pasture for about a mile, then a group of 4-12 houses and barns within the span of about 1/16-1/4 mile, then repeat. Of these groups, 4-5 per town seem to include the remains of an old school-house (in addition to the currently operating schoolhouse in the town center and a union high-school in a larger, central town or city). That could be enough to consider at least the larger groupings villages. Rural towns in that area seemed to peak in population in the mid-1800's, at a time when sheep farming was big. Then, the population could be close to 2000 people in towns where it it now closer to 1000. For example: <https://en.wikipedia.org/wiki/Shoreham,_Vermont>. In towns of that size in that area, town government is part-time, often volunteer, and town meetings predominate. Basically rural New England is one of many possible examples of places that were substantially populated before motorized vehicles, have not grown significantly since, and have little town-vs-town warfare. [Answer] There was actually a lot of interesting research done about this, for example the *Theory of Central Places* by Christaller (see <https://en.m.wikipedia.org/wiki/Central_place_theory>). For typical towns, he came up with 10-15 miles; but he establish different 'size' categories, where each size has its own hexagonal grid. [Answer] The maximum distance between any two adjacent towns should be such that an average person can travel from one to the other during daylight hours. Traveling in the dark is dangerous, so people generally won't make the journey unless they can be reasonably certain to arrive before sundown. J Bergen is partially right about U.S. towns for this reason. While Colonial America was much less dangerous than medieval Europe, the paradigm remained that towns should be situated about a day's journey apart. Even up to the 19th century, this was generally considered to be 12 to 15 miles. If you look on a map of the eastern U.S. (Pennsylvania for example), and follow one of the highways (U.S. route 11 for example) you'll find that the towns are generally 12 to 15 miles apart. [Answer] About 20 miles sounds right. For example, I live between the ancient towns of Dover and Canterbury, which are indeed about 20 miles apart. [Answer] 15 miles U.S. between towns. This gave farmers time 1 day a week to do the chores. Walk to town. Shop & walk home. Feed the animals. Go to bed or a 7.5 mile walk to town. That would be a 4 hour walk. Less with a ox or horse cart. [Answer] I would start with the map and characters' needs and go from there. 1. **Geography**. You wouldn't build a town with no access to water or bountiful natural resources (such as forests and suitable land for feeding livestock) would you? Seaside towns, towns by rivers, forests, and forts built on strategic high ground would be good spots for towns. After you mark these spots on a map then you can draw lines between them and note their distances apart. 2. **Characters**. Are your characters going to be traveling between towns? Do you need the story to go at a faster pace and they only need to travel half a day or two to the next town? Or perhaps it's more of a *Lord of the Rings* type of travel time - where it's more of the adventure along the way that counts and not so much the destination. [Answer] This was kind of standard till the 1900's in town spacing. The 15 miles. Do to time to get to town & back home for farmers. Even the railroad when built in America used this formula in town spacing. As were to put towns. For max profit. Bigger towns went were rivers joined or were roads crossed. It was kind of a world wide spacing till good roads & fast transportation was here. ]
[Question] [ I've been thinking about this concept for a while and have not been able to figure out what could be a plausible answer. It seemed appropriate for my first question on this website. Imagine an experiment where a group of approximately 20 humans are dropped off on a fairly small (~1000 km²) island that contains all necessary resources as they would appear in a natural environment. The group would then receive the challenge to **- starting completely from scratch -** build a fully functioning computer system capable of running at least Windows 1.0 with usable speed and then run it successfully as fast as possible. They would start off with no tools or resources. These are the rules and conditions that would be present: * The group of humans would not need to worry about life supporting and maintaining issues such as food, clothing, weather conditions, natural disasters and hostile wildlife. * The group would know **exactly** how to find and assemble **any** items involved in the process of creating the machine. * The group consists of young and fit humans that would not experience any social issues within the group, and would not tire from consistent 12-hour working days. * For convenience, we assume that the humans would not age or die during their participation in this experiment. * The island contains any necessary resource in completely raw form. Materials like metals may be present in a higher-than-natural rate to ensure there is enough available for completing the challenge. As I started thinking more about this concept, I began expecting the minimum time needed to achieve such a goal would probably be at least 5 years (*Edit: way above*). However I am probably underestimating the time it would take to obtain some of the necessary materials and build all of the advanced machinery that is used in assembling a fully functional computer system. Could anyone suggest a reasonable time estimate for completing such an extreme task/challenge? What would be the biggest obstacles along the way? *As this is my first time ever post on any StackExchange website, feel free to point out anything I should be doing differently.* **Edit:** The challenge does not require building a version of the hardware that was actually being used to run and interact with the OS. As long as it gets the job done and the system is able to run at usable speeds, it could be built from any material and can be as big as it needs to be. **Edit:** I have accepted Karl's answer as it portrays the most factual sequence of steps that would have to be taken in order for the team to achieve the necessary level of technology for building the machine. [Answer] This demands a full chemical industry developed. (Let's guess they can get at iron ore and coal somehow, and suitable material to make ovens, and you swiped a few axes, saws and shovels to start with. I cannot guess how long it might take to bootstrap those.) Factories they need to build in chronological order. * bricks, cement & construction supplies * blast furnace * machineshop * steel production * keep improving all previous production sites at all times * glass factory * base chemicals factory * advanced machineshop (lathe, milling machine) * polymer production * copper&electrical cable production * electrical power station (this needs a bit more thinking, might need to be quite large) Now you're in ~1890! * advanced chemical factory * aluminium factory * semiconductor factory * build first discrete electronics to help with all machining * make your first integrated circuits * build first computer with ICs, start programming * develop CAD/CAM * better computer, more highly integrated circuits * develop programming environment for the final task 20 steps, let's say I forgot another five. You can probably do every task in a year or two, if you have 20 people for it and know exactly how, but you will run out of personnel very fast. All the earlier factories need to keep running while you build new ones, and you will need ever more people to keep maintaining and upgrading everything. The factories have to grow all the time to produce base material for all the new things you "invent". And you need ever more people to do the logistics&infrastructure and dig up the base materials. My guess would be 35 years and 20000 people, depending on how you get past the first steps. Perhaps half a million man-years. You have no chance with 20 people. ;-) An open question would be how to power all this. Hydroelectric and coal could do the trick, but one would need an estimate of the amount of electrical and heating power needed. At some point solar power could come into play. P.S.: Afterthought: The personnel requirements could perhaps be halved if you're really crazy and make this system to collapse with the target reached, i.e. no resources left, factories&infrastructure ruined of old age, etc. P.P.S. I might add that I thought the people constructing everything still need to dimension everything, i.e. they know the general rules, formulas, physical constants, but don't have a readymade drawing for every machine. Giving them a huge stack of premade blueprints seemed like cheating to me, and impractical, because it'd be hard to know e.g. the exact mechanical properties of the stuff they produce, before actually doing it there. It'd be another 20 years of science&engineering today, to prepare plans for all contingencies. ;-) P.P.P.S. Why all the factories? The 8086 is at the top of 20 years of integrated circuit development, and you need a lot of electronics already to build and test the machines that are used to actually make one 8086. The last steps can probably be more manufacture than factory, but I am sure you'll have to make dozens of the ICs each time before you get one that works (how would you know that your wafers' specs are sufficient, without building even more sophisticated analytics?). P.P.P.P.S Why ICs? It is impossible to build a general purpose CISC out of discrete transistors and let it run at several MHz. A parallelised RISC supercomputer (like the CDC 6600 mentioned in the disc.), no problem, but we are talking binary compatible to the IBM PC. Further, millions of transistors for the SRAM would be a pain to build and assemble by hand, and the latencies in the long wiring (not talking about the capacitance and inductivity) would make it inoperational *in an 8086*. [Answer] There's only a few goals that are actual requirements and they have some low-hanging fruit: * CPU, the only unique part that we want to move away from is mechanical switches. Galena and a steel wire can make a natural contact junction as can rusty and non-rusty metal supposedly. One person has made some relatively simple [transistors](http://www.andaquartergetsyoucoffee.com/wp/?p=81), you could probably do something similar to that with the right chemical knowledge the materials used might even be simple to manufacture. I've heard current breaking down a dialectric can sometimes for junctions as well. * Battery, Lead acid kind. You would need to build capacitors to smooth the power. Lead, like the rest of your metals, would be in raw form (or near enough) and sulfuric acid can be made with choice minerals and/or iron or platinum. * Clock, you could make an inverter to provide a clock pulse or fashion a piece of quartz into a thin wafer (almost impossible but you only need to get lucky once). * Display, a little harder but you could make a motor that signals you in binary. Possibly set up a grid of them for a screen. * Input, crossed wires provide a keyboard input when they contact. You would build vertical and horizontal rows so they'te not touching and then pressing on a junction would complete the circuit. * Memory, can be made as core memory from raw metals. If you have raw materials instead of ores and a source of coal everything can be developed. Wax, paper, and electroplating can be used to build a circuit board if you feel it's neecssary. A solder iron could be made from a leather wrapped iron rod with solder being homemade (lead and tin alloy?). You can cold work your way to the tools and material shapes you need after you cast your initial hammer head and anvil from iron. If you spent about a week each on: * collecting materials * a kiln for your athracite coal to melt the iron, melt glass to make a case for the battery, etc. * make a bellows and other small tools * cast the anvil and hammer * making blueprints/designs * possibly one for papermaking * possibly spending an additional few months for collecting special materials. ...and a few months assembling the created parts; It still seems pretty reasonable to accomplish within a year given perfect knowledge, the right raw materials, and a decent set of able-bodies. [Answer] I am assuming they have all the knowledge necessary readily accessible, in form of books or a magic tablet which does not run out of battery. Your estimate is very low. It would take very very long time to get to a point to generate electricity. You need electronic machinery to build smaller electronics. Hell, even building a solder iron would take a very long time. Imagine melting and casting copper into stone to create wires. Also you might need to dig oil to make plastics, as some cables will definitely require insulation. Before you get to any of this, you will need tools to dig the ground. You will probably have to work with stone tools until you get to a point to make iron tools. To sum up, you will go through whole of industrial revolution and then some, where thousands of engineers were working during that period to advance the field. I am not including scientists as your people have the knowledge. All in all, I would guess it would take around 50 years, probably more. [Answer] Rather than reinventing most of industrial civilization from scratch, I think your engineers will be better off thinking 'big' and developing a mechanically actuated machine from simple materials, like wood and fibers. I'll continue the trend of your generous assumptions and assume that your operators will operate the system perfectly, so you don't break any of the components. I'll also assume they carve and position everything perfectly so that you don't have to worry about the inevitable wear issues with moving/sliding wood parts. It will be painfully slow to harvest all those resources with stone age technology, but still quite a bit faster than reinventing all of mining and metallurgy, let alone everything you need to manufacture semiconductor technology. I'm imagining a huge machine with: * A 'monitor' composed of patches of mechanically rotated dark/pale plant leaves as 'pixels'. You'd want to miniaturize this at least somewhat to make it usable, so this would probably be one of the most delicate parts of the mechanism. You'll probably also want to settle for a relatively low resolution. I'm imagining a vast array of sliding horizontal straight poles that adapt to vertical poles to rotate their corresponding pixels. You'd probably need to lay them out overlapping in 3 dimensions to get enough density. * Mechanical switches that transform translation of a pole into either coupling or decoupling two other poles (so they 'transmit' only when the 'base' pole is actuated.) Basically you have a logic system composed of latching relays, with signals actuated by translation (and likely adapted/routed via rotation in various places.) * Timing and power is supplied by people pedaling wooden wheels, with clever mechanical governance to transform into a clock cycle. This is where I doubt whether 20 people could supply enough power/speed to run 'fast enough' for your purposes. If it's not enough to run it 'live', you could store power using lifted weights or flywheels, so you operate the pedals for, say, a day, then you get a few minutes of runtime. Scale up as desired. * For memory bits, you can leverage potential energy from gravity to store (literally lifted) bit states, with a read and refresh logic. This is still a ridiculously massive engineering project, even if it is 'low-tech' from materials standpoint. Still, the basic components are all there to execute logical circuits and thereby build a fairly powerful computer. It's hard to estimate the labor involved, but I'd say you're probably still looking at a decade or more, just due to the sheer number of elements required. And that's assuming everything goes perfectly, with no mistakes made in manufacturing all these ideal parts by hand with stone tools. [Answer] See [the links](https://en.wikipedia.org/wiki/Steve_Ciarcia) to building the “MPX-16” from scratch in 1983. This is sourcing the integrated circuits that were available when such machines were built by IBM. You can see the overall complexity and scale of the design. Now you just need to build a silicon wafer “fab” and create the perfect crystal wafers… well, even if you supposed chipmaking could be scaled down to a home darkroom kind of thing, the industry needed to produce wafers is well beyond you little band. That will be true even for the roughest semiconductor transisters; e.g. the stuff the Apollo mission used. Any earlier technology would not be capable of running fast enough (as specified). Oh, and you want a CRT display to go with that? Again, we need *industries*, not a small party of individuals. [Answer] This answer focuses on the computer goal, rather than the process to create the computer. "As long as it gets the job done and the system is able to run at usable speeds, it could be built from any material and can be as big as it needs to be." If you drop the requirement for "usable speed" then a simulation could be done using anything as memory markers. Lay out a massive grid on the ground to represent memory, and fill it with some kind of markers that mean 1 or 0, or use scratches in the soil. Upshot: No industry required beyond feeding and housing and caring for the workers. Downside: Time - the computer will run at hundreds-to-millions of seconds per cycle, rather than millions of cycles per second. [Answer] If they know what to do then probably two major problems comes in to mind Transporting resources and gathering them is one problem Second problem is low number of those peoples. first is a problem because island is actually big, and if resources are scattered, it means pretty big distances. Getting-mining resources even is they are rich in quantities is not an easy task, and it gets not easier over time as demands will probably grow. Just moving 1 tonne at distance 10km with wheels etc without roads might occupy them all for day or more. But you have dig that tonne first, and it is not pure so it means to get 1 tonne of product they have haul more then 1 tonne of ore. So where resources are, in with form they are, surface of that island, distances might be bottleneck factors. Moving those resources across production complex is also a problem, gravity is a ... do not know the word, heavy might be. As for second problem, number of peoples, they have not just replicate and fast-forward stone-steam-electricity as it was done and scale it for 20 people, but it have to be done in the way specially designed for those number of peoples, needs should never exceed 20 peoples doing something at the time. With no automation - at steam era, you have to have peoples almost for everything, they should work, watch, control, oil things, check that water gets in the boiler (not all systems which are used for that are reliable, and they tended to break or get our of regime their work) - so basically for moderate size steam machine it needs 2 people - one feed it, one watch it will not blow up and that it still rotates(kinda). This get us to energy problem - how much energy can produce 20 humans with tools. At any point of that path stone-steam-electricity - there will be upper limit how much energy they might produce, in therms of power. So whole process should not exceed their power production capabilities, their controlling capabilities. Glass making may need 24/7/365 watch - so 2 people out of whole process, and if there will be more then 9 such process at a time - they will run out of peoples. And candidates for multiple points are chemical processes, there is a lot of chemistry involved in producing chips, not only for used chemistry in production, but used to produce that chemicals which are produced. Purity of chemicals might depend on bulk production, just because in big jar impurities form jar itself are less percentage then in small volume production. Some chemicals store not so well because of instability of them, impurity will grow over time - so it might be impossible to produce all needed stuff and make check-marks - or you produce 10 of them at once in short time or you produce none of them - just kinda exaduration, but who knows. Making the process which leads to end result for those 20 peoples is more challenging then just replication of what we have done. I'm very interested in looking at their model just for brief moment, very exciting. Sorry, but I'm not ready to estimate time, as have almost no glue what to do father then steam era. And not sure do they need 20m high refining columns for chemicals - if case they need to produce just one piece of that equipment which runs linux. Steam era, they probably might achieve it pretty fast, less then a year, if they have no problems to know what to do and skills needed to do that. For real situation with people (not robots) I would say no way for 5y, but robot style people, may be may be, I consider it as possible. But this number is as good for me as 10y or 15y or 2y. 50y? do not think so, or they can do it in less time, or they just can't. [Answer] First of all, let's look at the requirements for Windows 1, it is an 8 bit computer with 385k RAM memory. So, if you have space, it is possible. DIY computers are really not something difficult to make. [![Image from http://hackaday.com/2012/04/20/building-a-computer-with-discrete-transistors/](https://i.stack.imgur.com/dtv4F.jpg)](https://i.stack.imgur.com/dtv4F.jpg) Displayed here is a board with transistors, that together makes a 4 bit computing processor. In simplified terms, this is basically it, the challenge is to make $2^3$ times more efficient and smaller the oscillator (crystal frequency) can be increased and so small it fits in inside the area of a coin. But that wasn't one of the requirements. Now the problem is, to make it out of something that looks like this: [![replica of first working transistor.](https://i.stack.imgur.com/qaKn1.jpg)](https://i.stack.imgur.com/qaKn1.jpg) It would take a lot of space. A fast google of DIY RAM Memory shows that something similar could be made, fairly easy, where the true challenge is to make it small and modular. But given the means to extract the resources the area to build it, (I mean Boeing production size buildings), it could be done. Regarding the running speed, I'm afraid I'm not experienced enough in that area, to know what speed it would run but it would largely be controlled by the switching capabilities of the transistor but I could not find the datasheet of the "first transistor" but a general purpose transistor has a switching capability of about 300 MHz. [Answer] Putting things together is information. The arrangement of metal that distinguishes a pile of coal and rusted iron from tempered steel is information. The way we usually do this is through crude processes that generate gradients that rearrange the locations of the atoms in a favorable way, and we iteratively move towards the arrangement of matter we want. This involves the application of energy to generate a entropic gradient of the right shape, which is the only way we know how to mass re-arrange atoms into a new form. But it is just information. Some energy needs to be added to get some states from others, but the net energy difference after processing tends to be far far less than the energy used -- most of the energy is leaked off as heat, not captured. This leaked heat is entropy -- loose information. The ordered energy we use to induce the changes stuffs some of the information into the new structure, and the vast majority leaks off as heat. If all the humans know is our current crude methods of infusing stuff with the structure we want, then they'd basically have to reinvent industrial civilization. Time would be measured in generations not years, as they would have to breed a population sufficient to manage the industrial civilization needed. If they instead had *all of the information they need to make it efficiently*, and the ability to *exactly* use that information, they could literally walk around and hit things perfectly with hammers and cause them to reassemble into the shape they need. Remember, all that is required to uncrack an egg that fell off a table is the exact right set of taps, impacts and sounds. It is the lack of information, and the difficulty in doing the actions exactly (low energy, extreme precision) that makes this impossible. The easiest way for a human to uncrack an egg is to feed the cracked egg to a hen, or compost it and feed the food you grow to the hen. This level of knowledge and precision in action is far beyond what any human could do, but you did say the had **exact** knowledge on how to do it. And mere mortals have social issues. Clearly you are not talking about mere mortals, as they have no social issues. --- So if each woman produce 6 children per generation, 3 of which are women, and the population is half men, after 10 generations you have ~120,000 people. After 20 generations you have ~7 billion people. I'd expect it to be somewhere in that interval without perfect information. With **perfect** information, they walk around tapping things and those things reform into the exact ingredients they need. They touch them together, tap them, and they bond together. Their actions look more like magic than industry. [Answer] They can do it in seconds. "The group would know exactly how to find and assemble any items involved in the process of creating the machine." If their brain is programmed with what ever knowledge they need for making anything. Just make 1 of the 20 people the computer. The only real thing required will be a language to interact with the "computer" so that any one of the 19 other people using it can figure out what is happening, and since they already know everything they need to do, they can just do it. The "computer" can encode any information it wants into sound and the 19 people can decode the sound in their head into windows 1.0 UI. A person should be able to process any high level UI level command within a reasonable time with training, and since these people know everything they need, they should be able to do it. If above is not valid because they didn't create the machine. Then it would take 9 months for 2 of them to biologically create a new machine and then a couple years of training to get the machine programmed correctly. [Answer] For the sake of completeness, let me give you the perspective of an Electrical Engineer who once designed integrated circuits and knows a bit about the history of computing. Given the limitations proposed by the OP, it is ***IMPOSSIBLE*** to develop the technology necessary to build a computer running Windows 1.0. There ***IS NO LENGTH OF TIME*** that will change that. The mountain of technology is so large, the developmental basics so great, and the knowledge so specialized at thousands of points along the developmental path, that it's impossible. *Sorry* (I upvoted Karl's answer because it was well thought out, even though he's not familiar with some of the core technolgies... but as much as I liked the answer, this one needed to be provided.) [Answer] Any piece of technology that is newly developed is, at its time, the pinnacle, or the sum of *everything* and *everybody* that went on before, within the "light cone" of the involved people or logistic processes. In the stone age, presumably, this kind of "light cone" was relatively slim - individual tribes probably re-invented the same technology (sharp stones fixed to a stick) relatively independently from first principles. Over time, travelers or raiders brought ideas into circulation; culture developed. By the time of, say, the old Greeks (Alexander), Chinese, the Roman Empire etc., the light cone was - for the most advanced bits and pieces of their time - probably their core city state (and then shone outwards towards the "barbaric" regions they occupied). Fast forward today: the "light cone" that goes into our current products (computers, etc. - even in the 1980's) is arguably *incredibly* large. It is so large that we are incapable of, for example, determining the true economic footprint of most of our wares - we are not even able to measure/document the logistic and product chains going into T-Shirts, never mind electronics. Sure, a lot of our complexity comes from the fact that we not only produce one piece of everything, but do mass production; so on the face of it it may seem you can shave a lot off if you don't need that. But this argument does not work for your question. You *need* mass production for a lot of what you are doing - for example even your single Windows 1 capable machine needs lots and lots of repeated pieces (resistors, whatever). So even for a component only one or steps removed from your end product you already need to figure out the prerequisites to mass manufacture stuff. Surely not on the scale we have on Earth. You might argue that the knowledge of the goal and all the principles along the way would change the time line significantly; and in the ideal world (nothing gets forgotten etc.) it probably would. Still, as long as you have humans in the loop, you still need a *lot* of those, since every one is simply incapable of cramming arbitrarily much applied knowledge into their head. Finally, it is not like our technology was created in a completely planned fashion - we have demonstrated that this goes horribly wrong. The fact that we have (many) millions of people working in science and industry also enabled the evolution-like approach we have today - we are trying and failing a lot, and this is inherently important in the system. This kind of trial and error is a *feature*, not a bug. You'd arguably need to replicate it on your island - i.e., for non-trivial topics, you'd need multiple teams trying to achieve the same goal at the same time. And then we get to the crux: all those people need to be born, grow up, be educated, fed, clothed... and voila, there's our whole Earth economy as a non-optional pre-requisite. So, as you are limiting your time scale to well within a single generation, it's not possible for systemic reasons (not just scale). ]
[Question] [ **Closed**. This question is [opinion-based](/help/closed-questions). It is not currently accepting answers. --- **Want to improve this question?** Update the question so it can be answered with facts and citations by [editing this post](/posts/63416/edit). Closed 3 years ago. [Improve this question](/posts/63416/edit) Let's assume for a moment that [Santa does truly exist](https://worldbuilding.stackexchange.com/questions/13495/how-can-santa-exist-when-adults-buy-the-toys) in some form or other, however unlikely it may be. We can safely assume that he lives at the North Pole, provides children on the nice list with free toys every year, and generally brings happiness and festive cheer and encourages selflessness and love. For the majority of people, the belief in his existence fades at some point during childhood. As we get older we begin to understand that he isn't real, and as time goes on it seems that the age at which people stop acknowledging him is getting younger and younger. If Santa is real, then the lie that he doesn't and never has existed must have originated from *somewhere*, and is still being encouraged in the wider population even today. There must be a reason to maintain such a huge conspiracy as this, particularly one that is being pushed onto the only ones who know the real truth: children. Who is spreading this false propaganda? Who is feeding the myth that Santa is fictional? And more importantly: *why*? [Answer] Easy answer: Santa himself is spreading disinformation. Consider this: If you knew there was someone who handed out free gifts to people, wouldn't you want to go kowtow and make nice and otherwise try to curry favor in the hopes of getting exactly what you want, free of charge? Additionally, it would be a nightmare for parents to have to deal with children who always wanted to go to the North Pole. There's also all the laws Santa breaks every year that law enforcement around the world would be able to charge him with. Every military would be interested in getting their hands on the technology that allows Santa to break all those laws in one night and not get caught. [Answer] # Central Heating Manufacturers ### Wait, what? Santa comes down the chimney, everyone knows that. Back in the days of coal fires and chimneys that wasn't a problem, but now we're all on central heating and don't have chimneys, Santa can't get in. To be able to sell central heating and ultimately leave us without chimneys, the central heating manufacturers had to convince the world that Santa wasn't real so nobody would take issue with the fact he couldn't access new homes. This is why you now have to buy your children's presents yourself. [Answer] ## The Coca-Cola Company The Coca-Cola company already [acknowledges responsibility](http://www.coca-colacompany.com/stories/coke-lore-santa-claus) for its marketing department having created the modern-day image of Santa Claus, entirely as a tool to sell more Coke. It is not much of a stretch to assume that if he no longer serves their needs they would launch another campaign aimed at destroying him. Two equally-likely scenarios include: **Scenario 1: Coca-Cola is attempting to sell "The Gift of Coke" as a Legitimate Christmas Present** Sales of sugary beverages are flat in many regions and Coke is actively searching for a new way to sell their product. Seeing that other retailers derive a majority of their income from the Christmas season, Coke decides to get in on the market. Once the trend caught on however, that Jolly Old Elf started just GIVING AWAY their carbonated sugar water to kids! Cutting into Coke's profitability is unacceptable and, having already demonstrated that they can re-create Santa's popular image, Coke decides to take him down. **Scenario 2: Coca-Cola Diversifies into Other Areas Santa Competes with them In** As before, sugary beverage sales remain a challenge. Many states and countries are even passing laws that prohibit actively selling their diabetes-in-a-can to children, which are their next generation of consumers. But that doesn't mean that Coke can't start manufacturing action figures, right? Toys that just happen to include background items native to the storyline of the creation, like chairs, lamps... and 6-packs of Coca-Cola. But again the Jolly Old Elf rears his ugly head and is giving away toys to kids for Christmas! If kids aren't playing with toys that prominently feature Coca-Cola, they are not pushing Coke's agenda. And so the marketing department goes to work again... **Edit / Update:** In response to the comment that this may be an attack on Coca-Cola, I thought I would present some additional links that help cement the underlying scenarios as realistic. Note that all links in this answer are to the actual Coca-Cola Company's website, though more examples could be found elsewhere. If Coke was uncomfortable with any of this information I am sure they would not have published it. [Coca-Cola's Holiday Gift Guide of Coke-Inspired Presents](http://www.coca-colacompany.com/stories/holiday-gift-giving-guide-12-gifts-for-the-coke-fans-in-your-life) [Historical Coca-Cola Branded Toys](http://www.coca-colacompany.com/stories/collectors-columns-coca-cola-toys-and-games) (note how many have featured "Sprite", a character originally created by Coke to be Santa's elf!) [Answer] The evil **Toy Companies** of course! If Santa isn't real, there's no reason for children to behave well. If they don't behave well, then Santa will not deliver gifts to them. This means the parents have to step in to avoid the devastating disappointment their children would face by not receiving presents (when all their friends did) on Christmas morning for the minor crimes of shouting, crying and pouting. This means they need to *buy* the gifts rather than getting them for free from Santa. This has further adverse effects: If Santa sees parents buying gifts, then he does not deliver any for those particular children, because it would be spoiling them to give them *two* sets of gifts. This means that even parents may end up buying into the rumours that he doesn't exist! [Answer] ## A Corporate Campaign that put Everyone on the Naughty List Santa only gives presents to children on the "Nice" list - but rarely is it established what constitutes "nice" and "naughty". It is quite possible that Santa's standards of behavior are too high for most people to manage - and they are certainly too high for the capitalist pigs who run the corporations that produce gifts for parents to buy their children. At one point, Santa did give out gifts to well-behaved children, but the parents who were themselves naughty didn't want their children to realize they were being taught the wrong values, so they started buying presents for their children instead and claiming it was Santa. This was the beginning of the Christmas gift industry. The people in charge of the industry, of course, were jealous of the children who were still getting presents from the real Santa. Plus, they were greedy and wanted more money. So they started a massive campaign of corruption that trickled down into the lowest levels of society, contaminating the population with evil ideas so that there would be no one left on the "Nice" list and they could control the gift-giving. And it worked. Now there are no people left, not even children, who meet Santa's strict standards for behavior, so Santa spends every Christmas just sitting in the North Pole twiddling his thumbs and reminiscing on the good old days while corporations make money off of the naughty parents of naughty children who need to buy their children gifts so they can maintain the myth that they themselves no longer believe in. [Answer] **Possibility 1:** Judging by some of the answers to [How does Santa protect himself from IP lawsuits?](https://worldbuilding.stackexchange.com/questions/31987/how-does-santa-protect-himself-from-ip-lawsuits), it's very possible that Santa does this himself, for legal reasons. It's benificial to him to keep a low profile, and harder to have a lower profile than "doesn't exist". The greatest trick the devil -> satan -> santa ever pulled... **Possibility 2:** If Santa is a god, and his power comes from belief (as I proposed in <https://worldbuilding.stackexchange.com/a/63426/30470>), perhaps a rival god is spreading the rumours. A god of capitalism, shopping, parental generosity or some such thing might well have a good cause to do this. I don't claim to know the intricacies of inter-god relations in the modern world, but I doubt Jesus is completely above suspicion here, either. [Answer] ## Not only the children *but also the parents* need to believe in Santa (considered but rejected) Parents buy presents for their children, because they don't have faith in Santa bringing them. Suppose there is a Clause which says that if the parents don't believe in Santa, the children don't get any presents from him. There isn't anywhere in the stories (as far as I know) which says that children should suffer for their parents' lack of faith, but it's possible. We can disprove this though with the help of orphaned children in warzones. They have no parents or generally any care-givers to take on the parental role, but they don't get presents. So forget this one, and move onto another more interesting possibility. ## Santa's definition of *naughty and nice* is not the same as ours (considered but rejected, although interesting) Suppose Santa has a completely different moral code to us. He's a different species with advanced technology, after all - who can tell how he thinks? Human ethics have evolved with improved knowledge, longer lifespans, and rejection of corrupting mythologies and oppressive customs. This is good for society as a whole; but it may not meet Santa's requirements. Suppose Santa is a trickster god. In that case he might choose to reward children who are comprehensively disruptive to those around them. Since society trains children to **not** behave this way, very few children will meet his requirements. This seems unlikely, because in the environment of general scarcity which existed before the last few decades, society didn't have enough spare capacity to deal with awkward kids. ### Blood sacrifice! More chillingly, what if his red suit reflects something else though? Midwinter sacrificial rites were a major part of many European traditions. Usually these only involved animals and not human sacrifice, but even animal sacrifice is no longer part of our culture. So perhaps children are no longer getting presents from Santa because they aren't killing animals in his name. This would tie in rather nicely with everything we know about the season, everything we know about European winter traditions, and with changes to social norms. Interestingly, this hypothesis is also impossible to falsify. Even if a child killed an animal, a formal sacrifice requires some ceremony around it otherwise it doesn't count. Any ceremonies attached to Santa's sacrifice have long since been lost, and there is no way to recreate it because we wouldn't even know where to start. (We would also probably fall foul of animal protection organisations!) I think this gives us the answer. Not only does it fit all the available facts and all the history, but it also gives us a reason why we cannot ever get back to Santa bringing presents for children. *And like all good Christmas stories, it is completely unprovable...* [Answer] ## It started out as a lawsuit. When several children failed to receive the presents they asked for from Santa, an outrage broke and a class action was proposed against the national post office. Said post office, with it's army of lawyers went to the trial with a simple defense: We *did* deliver every single letter (as we always do), but who knows if Santa even exists to answer them? Soon after winning the case, an army of lobbyists was created that somehow made the government announce that Santa's existence is under question, thus the myth was born. [Answer] It is OPEC. OPEC are "well known" for suppressing any and all technology that does not rely on pulling long dead trees out of the ground and setting fire to them. Santa is literally sitting on a transport revolution; a passenger vehicle with an engine that not only runs on sustainable biofuel, but reproduces itself and in the main repairs itself. And ON TOP of all that, it is extremely cute too. This vehicle - featuring an all wood and therefore again potentially sustainably constructed passenger and cargo compartment - is faster than any hydrocarbon powered vehicle in existence, and can carry far higher loads. If people knew Santa was real, OPEC would be instantly blown apart. Many very, VERY rich and powerful people depend on the human race not knowing the truth. WAKE UP SHEEPLE. [Answer] The answer is quite simple really: ***Every other magical creature out in the world trying to protect itself (and also Santa cause he's a nice guy).*** Think about it. If Santa and his elves exist, then elves exist. One answer I saw showed that if Santa's elves worked legitimately it would take hundreds of thousands of elves to make the presents. However, that would imply that a large Elven populous exists in the world as not all Evles work for Santa (obviously). So we now have an Elven race in the world.So why not Goblins (who in some stories are Elven cousins), Trolls, Ogres, Leprechauns, Dragons, etc. In such a world, these creatures will want to stay hidden in the modern world. Why, you ask? **Because the government will use them for things**. For instance, we have bullet proof armor that looks like scales. It was on a tv show once like Mythbusters or something. Where did that come from, you ask? Weapons tests on Dragons. Tanks? **They were designed to take out European dragons enraged by all the poison gasses during WW I**. In this world dragons are intelligent (if not sentient, enough to recognize that the puny humans are poisoning its nest and that all of them need to be removed for its safety). Weapons of mass destruction? **Hydra/Kraken killers. It's easy to kill a 10-story tall monster that doubles when you cut its head off (or shoot it off with a gun) when its atoms virtually disintegrate.** Grenades? **Developed to make trolls and ogres on the battlefield go boom** The list goes on and on and on. Simply put, **humans can be the real monsters from nature's perspective**, and in a world where humans know superpowered monster species exist you can bet your money that the pentagon and every weapons department will be doing whatever it takes to replicate their powers and exploit their vary DNA. Monsters/magical creatures will want to hide if only to avoid becoming the thing that the government tests vaccines on. After all, Elves have no *human* rights and Elven DNA is going to far closer than monkey DNA. Santa Clause is a nice guy. If he hears that his fellow humans who aren't living thousands of years from use of magic are experimenting on monsters and need to be convinced they've all died out/never existed **he'll help them out**. Heck, his elves might have threatened going underground and ditching his operation completely if he didn't try to take some precautions. [Answer] **Nobody is responsible, Santa was sick at a time and is now literally locked out for most of the population.** Santa has magical powers as evidenced by the flying sled and his ability to retain at one of the most inhospitable spots (The north pole is at the sea). Santa *did* provide children with toys and visited them together with their parents. To come up with the growing population, he had to include stricter and stricter conditions for his visits. Parents where the children were not visited had to pretend that Santa came or even using impostors. But the families who were visited were incredibly happy. But finally even Santa overexerted himself and was unable to visit anyone for *decades* (You know, getting sick is very serious if you are supernatural). In this time people wondered where Santa was and his believers dwindled down...as there was no proof to Santa due to his magical nature, adults were more and more convinced that they duped themselves. Their children were absolutely devastated, so adults needed to play Santa. Santa recovered finally and unfortunately found out that he cannot visit people anymore. You see, magical beings cannot cross the boundaries of a home if uninvited (It is not only vampires). Only very few people (the last believers) are visited now, sometimes it was tried to convince other people, but the results were disappointing at least (You know, those visits from gentlemen with white uniform and some cloth they want you to test out). That is the starting point. [Answer] # Church "Brothers, fellow supreme representatives of [the revealed religions of the world](https://en.wikipedia.org/wiki/Revelation), thank you for convening at this secret meeting. We — the church — concede that **our** supernatural fatherly figure with a Nice List and a Naughty List, does have His quirks and... well... slightly ethically questionable notions. Such as... * That you [actually **start** on the Naughty List](https://en.wikipedia.org/wiki/Original_sin), not for something you did but that your supposed forbears did * [The occasional temper tantrum](https://en.wikipedia.org/wiki/Genesis_flood_narrative) * The requirement not just to behave nice to your fellows but to **love** Him, and [love the people that wronged you](https://en.wikipedia.org/wiki/Turning_the_other_cheek), at all times, and [never stop doing it](https://en.wikipedia.org/wiki/Apostasy), lest you incur His wrath * The promise to [punish you after you are dead, forever](https://en.wikipedia.org/wiki/Hell), unless you have gotten off the Naughty List by then * The very odd notion that you [can get off the Naughty List by supposing that someone else got on it for you, 2000 years ago](https://en.wikipedia.org/wiki/Atonement_in_Christianity), and got not just a coal in their stocking for it but a red hot burning one * He does not reward you by this — or any — midwinter feast... or even in this life. [Only when you get to the next one](https://en.wikipedia.org/wiki/Heaven). ...and we also concede that "Santa" does not behave in any such way, and that [Santa does reward you in a very tangible and regular manner](https://en.wikipedia.org/wiki/Gift). So — clearly — we have a bit of an image issue in face of the competition. What do we do?" "Hm... how about if we start a secretly funded campaign — not traceable to us, of course — that says Santa does not exist?" [Answer] # The Police. Santa is clearly a criminal, breaking into **millions** of homes, stealing their hard earned milk and cookies, and leaving. That kind of reckless lawbreaking **MUST BE STOPPED!** Everybody knows that the number one way to stop Santa Claus's magic is to not believe in him, so the Police spread a smear campaign to try to weaken him, so that they can finally have the advantage! *The police chief was clearly not a good boy.* [Answer] **The Disenchanted** Of which I am a member. For years, I would watch Natalie Wood get a house from Santa, and a father, and a sane by the fireplace. Each year, I wanted those things. Each year, I got a toy. Then, the year he gave me a jar of grape jelly...from then on, I swore a vendetta...a jihad...I put a price on every elf, flying reindeer, and jolly old fat man in a flying sled. And, I am not alone. Millions are with me. We sit, each Christmas Eve, in a duck blind attached to the house...waiting. He refuses to show himself. By using social media, we spread false rumors of his non-existence. We hope this will entice him to come out from under the rock he is hiding to make a press conference to put an end to the rumors. And, at that press conference, we'll be waiting...no, not all of us. But, he'll never know if the cameraman is hiding a gun, or maybe the podium mic has C4 in it. Was it a flashbulb pop or gunfire? At first, no one will know, because his red suit hides the blood well. Until the loss of blood causes him to collapse, and then it is too late. --Just to make sure no one thinks I have lost my rocker, it's just a coalescence of several movies starring Wesley Snipes, Marky Mark, Clint Eastwood, and Gerard Butler. [Answer] **Vatican and the Pope** The name Santa Claus suggests that he is a Saint. For sure the Vatican should know whether such a Saint exists or not. The Vatican always pronounces you a Saint after death. Such as Mother Theresa. Such as Saint Nicholas. Santa however is still alive. One popular saying is that Santa Claus is Saint Nicholas. Eastern Roman bishop Saint Nicholas, unlike Santa, is dead (\* 15 March 270, Patara, Eastern Roman Empire, + 6 December 343). He originated not from the North Pole and never visited the Pole. If Santa was a Saint he would be dead according to Roman orthodoxy. So it is very easy to argue that Santa was "not real". My assumption goes like this: The Vatican spread the misinformation that "Santa" was Saint Nicholas(Sactus Nicolaus), which then became Dutch 'Sinterklaas', English 'Santa Claus'. In reality he is a Germanic nordic god who administers the wild hunt. In the 20th century he teamed up with the Coca Cola Company and other players in industry, to jointly pursues his mission to undermine Christian values and promote consumerism. Together with Coca Cola he came up with the idea to mock the [Camauro dress of the pope](http://news.bbc.co.uk/2/hi/europe/4551348.stm), to make the Pope a laughing stock. Just like left wing pacifists who wear army clothes, it was an act of subversive cultural approbation. [Answer] # The Naughty There are a lot of naughty people out there who think themselves nice — or want others to believe them nice. When they don't receive presents on Christmas, that causes a problem. Those who believe themselves to be nice find it much easier to believe that Santa doesn't exist than to come to terms with the fact they aren't actually nice people. Those who are invested in keeping up the appearance of being nice will insist on making others doubt the existence of Santa. Either way, the spread of disbelief in Santa is an inevitable consequence of how he operates. [Answer] **The People who insist that P does not equal NP** Santa is flying his sleigh to visit every house in the world. He clearly has to visit all of them, but the [traveling salesman problem](https://en.wikipedia.org/wiki/Travelling_salesman_problem), which this pretty much is, does not have a better known solution than O(n^2\*2^n) time, so Santa has obviously figured out a much more efficient solution, since there are a huge number of houses in the world. If Santa had found an efficient algorithm, it logically follows that P=NP. And, given [the large number of consequences of such a proof](https://en.wikipedia.org/wiki/P_versus_NP_problem#P_.3D_NP), it is completely believable that many people would be trying hard to prevent this fact from becoming well-known. [Answer] ## People who haven't done any research: The first reason they say Santa is not real is BECAUSE THEY DIDN'T GO UP TO THE NORTH \*\*\*\*\*\*\* POLE AND GO BLOODY LOOK FOR HIM! OH... BUT THAT DOESN'T STOP THEM FROM **ASSUMING** (*keyword: "assuming"*) HE'S FAKE! You see, the reason most kids believe in Santa is because they have actually seen him, but unfortunately, we live in a (messed up) society where, when kids tell an adult something, the adult assumes the child is imagining it. This is why Santa only visits the kids because adults wouldn't believe it is actually him, I'm guessing it hurts his feelings when people say he's not real, so he puts that person on the naughty list, and that's why 99% of adults don't find Christmas presents under the tree on Christmas morning. This gets even worse when those very kids (who may be educationally / emotionally / generally benefiting from those very presents that Santa is bringing them) are also led too believe that Santa (or anything else they've told the adult) is just a figment of their imagination. In my honest opinion, when you take presents away from a child (by leading them to believe that Santa is not real) they loose the one thing that keeps them happy (toys). Meaning that they might go and look for other things to make them happy and these *"things"* might not always be *"good things"* (E.G: drugs, crime, etc...). And it doesn't stop there.... The parents don't even have to buy or pay for these presents and for some weird reason *"they don't want them"*...? What a sad world we live in... But, it doesn't need to be that way. We need to protest this "un-holy" social behaviour and start letting kids know that its absolutely OK to believe that Santa is real. Heck we need to start **telling** them that Santa is real, then (and only then) will the world become a better place. [Answer] Just like in > > [Stranger Things](https://en.wikipedia.org/wiki/Stranger_Things_(TV_series)) > > > The conspiracy is run by the Department of Energy. [Santa travels at 1800 miles per second, carrying lets say 1 million kg of presents](http://www.telegraph.co.uk/topics/christmas/8188997/The-science-of-Christmas-Santa-Claus-his-sleigh-and-presents.html). This is [10^15](http://www.1728.org/energy.htm) Wh of energy. The world uses [10^13 Wh](https://en.wikipedia.org/wiki/World_energy_consumption) of electricity in a year. So Santa uses more energy in one night than humanity has used electricity in its existence. The Department of Energy is keeping this vast energy source from us. But why? [Answer] Corporate marketing flacks trying to sell things to teens. Teenagers are a valuable market segment, but a teen's spending is proportional to their independence from their parents. Teens are idealistic. If Santa is a lie, what else are Mom and Dad lying about? Better go to the mall and hang out with the other rebels to figure it out. [Answer] ## Crackpots Just like with the moon landing, 9/11, the Holocaust, flat Earth, or time travel, there's going to be people who dispute the existence of Santa. Consider that, in such a world where Santa exists and performs the tasks we commonly associate with him, he is scientifically provable. Maybe not as a jolly fat dude with superior technology, an army of GMO pygmies, and a herd of autotelekinetic reindeer, but at least as something that leaves unsourceable, gift-wrapped goods in people's living rooms throughout the world. At minimum, *something* is causing presents to appear and most parents are denying it was themselves. Children grow up later and, instead of deciding he doesn't exist, see evidence that he does indeed exist. (It might even be a case where a religion grows up around Santa. While such a thing in our world would be relegated to cult status or associated with an otherwise non-Santa-centric religion, in a world with a provable but difficult-to-pin-down Santa, there may be a better chance for a Santa-centric religion to gain legitimacy.) [Answer] ## International Panel on Climate Change [Whelkaholism's anwer](https://worldbuilding.stackexchange.com/a/63628/3096) is close but critically misses the point1. Yes, Santa's sledge has everything a vehicle needs: flies, is silent, is fast, is secure (0 recorded accidents in over 2,000 trips around the world). But it has a fatal flaw: **Reindeer.** It is not just that there are not enough reindeer to power everyone's magic sledge; with time they would be breed in captivity or cloned to provide every family with their own sledge. This is when things would go really bad. Because, while these animals would want us to believe that they are just lovely and inoffensive, the reality is that as many other grass-eating mammals, these are deadly machines designed to produce... **Methane**. Methane gas (CH4) is way worse2 for the greenhouse effect that CO2. And the IPCC is bound on fighting the greenhouse effect. Clearly this is something that the men in black of the IPCC are trying to prevent. In fact I am almost sure that the IPCC has already kidnapped Santa Claus (or worse). I base that affirmation in the fact that, for the last years3 Christmas presents have been missing. I have been trying to warn the public from my twitter account, but for some reason it seems that lately some ridiculous conspiracy theories have been getting all the attention while this well reasoned, honest, urgent warning has been unnoticed by the media. THESE ARE THE FACTS, MAN, THESE ARE THE FACTS! --- 1In fact I would guess that Whelkaholism is actually an IPCC operative in charge of missinformation. 2This is for real. 3Curiously, since the same year I moved away from my parents'house. [Answer] ## Criminals ### (i.e., Criminal Organizations, and their Recruiters) I’m thinking of people like [Fagin](https://en.wikipedia.org/wiki/Fagin), from Charles Dickens’s novel *Oliver Twist*.  The belief in Santa Claus provides material motivation for being good/moral (“nice”).  Disbelief in Santa diminishes and dilutes the notion that bad behavior has punitive consequences, and allows immorality to flourish.  This makes it easier for gangs to find people who are predisposed to crime. --- Also, ## Toy Merchants (Manufacturers/Sellers) (I realize that this idea was suggested in [another answer](//worldbuilding.stackexchange.com/q/63416/20215#63437), but I believe that my rationale is slightly different.) If adults believe in Santa Claus, they won’t feel the need to buy toys for children.  Nice children will get free toys from Santa, and naughty kids will get … what they deserve.  (Exceptions: parents who are “enablers” will buy gifts for their brats so they don’t have to suffer the consequences of their actions.  Some will give presents to buy their children’s love.  Those who are themselves immoral (or just excessively non-judgmental) will buy toys for naughty youngsters because of (or despite) their moral orientation.) Toy merchants need to discredit and delegitimize Santa Claus in order to create a market for new, human-made toys. [Answer] **Misinformation creates itself** Just as with many other scientific facts a significant portion of the population disbelieves, it is a matter of anecdotal evidence convincing individuals of a falsehood, and their internal biases working their nasty magic. In other words, as people grow older, they begin to assume Santa is not real given that most of the evidence they are exposed to during their daily lives seems to point at that conclusion. Since Santa is such a relatively small phenomenon, and by definition (of him being magic) it can't be reliably proven to a wide audience, people end up believing whatever they feel more comfortable with, and for an adult it is easier to rationalize Santa as a made-up fantasy to make kids happy, than to accept the existence of a physics defying magical being of pure goodness (or evil, depending on the mythology). [Answer] The Society for Polar Elvish Welfare has been spreading these rumors for centuries; the more people they convince that Santa isn't real, the less burdens are placed on his elvish toymaking slaves, and the closer they get to their goal of Elves educating themselves in their spare time and, dare I say, even rebel to throw off the yoke of their oppressor! [Answer] [![enter image description here](https://i.stack.imgur.com/dFNqo.png)](https://i.stack.imgur.com/dFNqo.png) The chimera is spreading rumors that Santa is not real.She's jealous that kids get presents while all that she gets is a chunk of meat! So her business 39 makes dubious dealings with Santa and spread rumors that Santa is not real. She needs everyone to stop believing in Santa and prevent him from delivering presents to make things go her way. [Answer] **Parents** They dont like the idea that some fat dude brings moar fun to their children than they. Also they do not want to cover him with back-up gift, in case their children suddenly become too bad for free present. So parents try to raise reasonable and educated people to stop worshipping the Red Santan PS. No kidding. This is serious discussion of "alternate-reality" and "santa-claus". ]
[Question] [ **A society of your typical beings from beyond the veil of reality have recently encountered the bounderies of the realm humans call home.** They studied our universe, via their own incomprehensible equivalent to what we call science and eventually learned how to generate a nightmarish portal (fueled by the screams of never born children) between their dimension and ours. One side of the portal happens to have been tethered to a previously insignificant asteroid located between Mars and Earth. The portal is small and extremely unlikely to be spotted by humans. The eldritch abominations can see us just fine however, and though, even after extensive observation, they still don't really understand our way of life or the way we think and percieve the world, they gradually do start to "understand" that humans are suffering and require help (in the same way that you can "understand" that a bee repeatedly bumping into a window "wants" to go outside). --- As they are not malevolent, they try to communicate with us and aid us, but each attempt simply ends up in a cult, a bunch of dead/insane people and the remains of a couple dead shoggoths being studied in some human lab somewhere (before the scientists inexplicably and inevitably go crazy and blow up their entire research facility along with themselves, of course). --- The uncanny horrors soon realize that our reality seems to be bound by some sort of framework, some overarching rules that the locals apparently call "logic" and "reason". Unfortunately, by their very nature (and by the very nature of anything else from the nightmare domain), these horrors seem to disrupt, corrupt and utterly destroy any semblance of the notion just by their mere presence. Our reality is simply too fragile. Even the space around the portal they set up is becoming increasingly unstable and is now prone to sporadically erupting with tentacles, 19-sided triangles and angry gramophones. --- Accounting for the fact that the literally mind-destroying influence they tend to have on our world is completely unintentional and uncontrollable: what methods could this species use to help (and optionally interact with) humanity in as broad a sense as possible? [Answer] So, these friendly neighborhood Eldritch Abominations (EA) would like to help the neighbors out? It really depends on what they are capable of, what sort of stuff the are inclined to do. There are a few things the EA need to do before they set out to help us. **Communication** First, they need to find some way to open lines of communication. While cults and crazy aren't exactly a positive thing for humans, they might be worth it if the information the EA's have is good enough. Perhaps a layer of abstraction is needed, to isolate the irrational from everyone else. Perhaps the Vatican or EU could assist in the creation of a more stable cult. In fact, I think it might be possible to fight disorder and irrationality with order and bureaucracy. We'll get the Germans on it. **Framing and Science.** Secondly, in order for us folks to use EA technology or practices, we need to come up with some sort of system through which we contain EA tech (Frames). I think, once we get our cults up and running, we could investigate this further. I suggest looking into promising ideas such as pentagrams and Altars. In order to leverage either EA technology or EA techniques, we need to understand. Depending on how mind-warping this stuff is, we can either understand how it works, or understand how to use it. If we can understand how it works, we can work with it. If we only understand how to use it, then we can only work around it, build on top of it. **Unexploited resources** You know, we humans are really inventive. Think of every description of Hell you have ever read. Now, think of scientific experiments conducted on civilians in WWII, or any other source of unapologetic, shocking cruelty. It is clear which one is worse, yes? It is equally clear which one is more inventive. If the EA's can power a portal using the screams of the unborn, just think of the potential! Now, we ought to restrict use of EA tech to morally defensible actions. The screams of the unborn were previously underutilized. They were, for our purposes, just sitting around, unused. They are already dead, so nothing wrong with leveraging them to the fullest. I think we can find plenty of stuff to exploit without permanently damaging living humans or their immortal souls. **Conclusion** In the end, all you really need is to have the portal discovered by some open-minded bureaucrat with a taste for lovecraft and an obsessive devotion to safety regulations. [Answer] "You know", Sog-Yogthot (no relations) said to I'g-m'ell over by the Shoggothnut table at the committee meeting for the betterment of the human realm. "The humans world is really dry, how can they breathe? I'm going to send them water. Does forty days and nights of rain sound roughly enough?" "Dunno", said I'g-m'ell (who was more of a creature of eternal fire itself) "But they do look a bit like Deep Ones, all bipedal and furless, and they sure didn't like when I set their forest on fire. Can't hurt." --- "Ok...", said Xaxhazztrax the Daemon Chairman, "Sog's rain idea was a flop. Clearly the humans aren't Deep Ones. Good thing one of them built a floating box." It was unclear to the assembly exactly how the human had gotten all the animals into his vessel, but hoary Nodens looked a bit smug. Then again, hoary Nodens always looked smug. Who invited him anyway? Was he even part of their pantheon? "So what do we do now?", a lesser servitor of Miihyagaa piped, his mistress silently brooding with her seven eyes fixed into the aether as usual. "We've given them fire, that didn't work. We've given them water, that didn't work. My mistress proposes that we call this project quits." There was a general murmur of agreement. "No!" Zblu'tras said firmly. "Our mistake was clearly focusing on altering their environment. They seem to have adapted well to it. We need to ennoble their spirits. I shall give them... art." --- "My hearts were in the right places," Zblu'tras defended itself. "But who knew they would take the gift of music and pervert it so? This cacaphonous 'pop music' is clearly not what we intended." "Don't forget that guy who made flesh sculptures out of his neighbors," another servitor of Miihyagaa squealed with delight. "My mistress especially enjoyed that part, even if the neighbors clearly didn't." Xaxhazztrax the Daemon Chairman sighed. "Oh well, we can't say we didn't try. Who votes we clean the slate with a comet and see what the bugs can come up with instead?" [Answer] As has been explained in another answer, the eldrich horrors do seem to realize that they have a negative effect on humans, and they want to *benefit* humans. The logical thing to do then, is identify what *other things* also have a negative effect on humans, and then systematically expose themselves to these other things. Since they seem to believe that insanity, cults, and scientists blowing themselves up is not beneficial, I believe they might decide that terrorists blowing themselves up as part of an insane cult is also not beneficial. Logically then, they would seek these people out and either suck them into their own dimension (fun new playthings!) or expose themselves to them in various ways, inevitably destroying their minds in the process. For whatever reason, they have deemed past efforts to contact humanity not beneficial, so it seems plausible that they would look for activity that follows the pattern of their own interaction with people, engendered by other people, and "connect" with those other people. Is a warlord butchering children? Pay him a visit. Is an insane cult about to feed poisoned kool aid to their own children? Looks like a good candidate. Is a performing artist having a special exhibition involving bodily fluids? Perfect example... oops, maybe that was considered *beneficial* by humans??? Very strange... This is similar to the "Dexter" or "Punisher" type anti-hero. They are heroic because they channel their own instinct to kill against the very worst kinds of people. Of course, from the human perspective, there might seem to be this pattern of always finding a connection to the Eldrich Horrors every single time something really awful happens in history. Human demon hunter types might draw a certain conclusion from this... and that is the stuff of good story plots. As an aside, if their portal increases in instability, the thing to do might be to "taint" it with matter/souls/whatever that actually belongs in the human dimension. Hence, they might decide to bring some of their "targets" to the asteroid near Mars and integrate them with the portal in order to stabilize it. [Answer] It really depends a lot on what they are helping us to do. When they look down upon humanity, in its struggling, what do they think we need? As these sorts of stories go, they will probably horribly, oh so horribly, misinterpret the desires of humans in particular and humanity as a whole. So what is a likely predictions of what humanity needs based on their observations and how would they try to help. ## Death Humans are dying by the billions, literally every human dies, what a horrible waste. This is obviously a terrible situation, abomination never die, they simply fade into obscurity or transform into a new abomination, this death thing must be stopped. We could... * interbreed with the humans to form a new undying master race of human-abomination hybrids! * kill all humans thus preventing more from dying, in my eldritch ethics this is totally justifiable. * bring them back, the dead must rise! This may look ghastly to the humans, but the undead look like pretty nice people to us, oh look they bite. [Answer] **Scare people to death** Literally, exactly that. With their outworldish sense of morality, they could, after thorough analysis, choose the people who bring most harm to our realm. And then try to communicate with them. Not only would they help us directly by removing all the bad people, but they would also build some good reputation as scary but just creatures who help us build better world. After some time, people might even overcome the fear and contact them despite the differences. [Answer] **Space** We like breathing air and drinking water and not getting burned, frozen or irradiated. It looks like that only works on Earth. If they made a few extra earths for us to play on that might be friendly, so long as they took the care to not add too many tentacles, removed any "made in dungeon dimensions" tags that humans might go insane reading and avoided putting them in collision orbits with anything. A staircase out to space sounds nice, but working out how to make one without destroying the crust or using materials that cause monsters or madness to consume humanity is trickier than it sounds. **Resources** We seem to do a lot of work to purify some elements out of the crust only to mix them back up. Maybe a mountain or two of a gold, titanium or steel alloy would be well received again being careful not to squash, cronenberg, or contact any humans. Lots of uranium sounds valuable, and there seems to be lots of concern about who gets the limited amounts available, but every time you start getting enough together to call it interesting some of it turns into something else and the rest gets really hot. **Not killing us** It turns out it's really easy to kill humans (and we don't seem to like it when they are brought back) so maybe diverting some of the problems they see wiping us all out would be acceptable. If there are some asteroids coming our way in the next few centuries it might be neighborly to see to it they miss. Big solar flares and random large x-ray bursts also are some concern. It may seem like a good idea to remove the weapons we have for killing all of us off, but we are pretty good at killing each other with all sorts of things, and would probably try on a pretty large scale if all our bombs disappeared or turned into unmentionable horrors. Similarly we seem to be getting ready to do ourselves in by killing off all other life with poison and heat, and maybe taking a few hundred billion tons of carbon dioxide from the atmosphere or some of the more toxic pollutants we've added to the ocean wouldn't be a problem, but they would need to be extra careful to avoid disrupting the balance more than we are. And again I can't stress enough how much I enjoy not being turned into or eaten by a monster. [Answer] So if I understand this correctly: * The eldritch creatures believe humanity is suffering and want to help * They don't know *how* humanity is suffering * They do not understand the concept of reason * They do understand that trying to communicate with us results in death and/or insanity Uh-oh. This reminds me of the classic example of a "benevolent" AI that's been programmed to minimize human suffering. The AI decides that the best way to end the suffering of humanity... is to end humanity. No-one can suffer if there's no-one left to suffer. If the eldritch creatures think the same thing, then they can easily open up another gateway on Earth and stream through, driving anyone who sees them to madness and death. Humanity will be wiped off the face of the planet, and as the last humans succumb, the eldritch abominations will climb back through the portal thinking, "Job well done." [Answer] Start a campaign to find the most balanced person on the planet. You do this by starting an [ARG](https://en.wikipedia.org/wiki/Alternate_reality_game) on social media, trying to mimic human logic as closely as possible, but with a tiny bit of EA logic thrown in. Gradually, over weeks and months, ramp up the EA logic, until you find an individual that has a mind strong enough that they wont break. Once you find this individual you can contact them more directly, though maybe still in the context of the game, and tell them of your desire to help humanity, taking their suggestions on the best ways to do that into account. Give them the means to generate funds by sharing eldritch technologies to be patented and developed. Things like portals that use tunnels through eldritch space of zero length to bring cities closer together, streamline transportation, remove the need for fossil fuels. It's likely that at zero length the tentacles probably won't be able to squeeze through, and probably no one will stay in the portal mouth long enough to really go mad... I mean, I don't think it's cumulative. Likewise, the energy potential of the eldritch realm is something that could be harnessed to remove the need for coal power plants. Tormented souls are a renewable resource. With the funds from these and other breakthroughs, you can pay for media that will slowly educate the masses on the eldritch logic and concepts, as well as introducing the idea that eldritch horrors might not actually be evil. Things like books, games, movies, etc. can be used as channels to introduce the wider populace to the ideas, and hopefully, slowly, over time, people will get used to the idea so that when the great old ones finally come through, the loss of life will be minimal. If all goes well, we can keep casualties below 50%. [Answer] The Eldritch Abominations 715 Pi th illogicians conference was called to disorder. "We need to help these humans, what can be done?!" Pronounced the chair (a note to the reader, this is a literal chair, not an abomination that is chairing the conference. People were listening to the chair though, because it made good points). A well feared and respected Abomination walked up to the podium to speak (a note to the reader, the actual direction the Abomination walked was Charmwards, but up will suffice). "It's simple. Abominations do not have logic, and we are happy. Humans have logic and are unhappy. Correlation may not imply causation, but it does waggle its eyebrows suggestively and waggle (a note to the reader, this is definitely not plagurised). Logic makes people unhappy and we should destroy it to help them. Another Abomination spoke up, this one a freshfaced youngster of only 19 cycles of expansion and contraction of the universe. "But too little logic is bad for them. The humans seemed upset last time. The Abominations quickly agreed that logic should exist only in moderation. A plan was devised. The Abominations would visit the human's logicians conference, that was going on simultaneously (for certain definitions of simultaneous). They would reveal themselves to the logicians, the humans likely to be most resistant to the Abominations effects. Then, the logicians could spread this message to the rest of the population, but sugar coating it a bit. That way, logic would be partially destroyed, the general population would be happy, and maybe the logicians would go insane after doing their job for the greater good. So they turned up to the logicians conference, did their usual abominationey thing, and then left, eager to spy on the results of their genius from afar. The logicians finished up their conference, and went to various pubs nearby. One started talking to two the patrons. The Abominations hearts waited with bated breath - it's starting, soon humanity will see that they would be happier if they mostly rejected logic. The two in the pub turned to each other and said "did you understand any of that?", then shrugged and return to their beer. The Abominations were puzzled. Their messengers weren't having an effect. One undergrad abomination piped up "Maybe beer is the problem" [Answer] # Super Powers We could help humans by giving them super powers! They use "their own incomprehensible equivalent to what we call science" to give powers (or change their body, etc.) We don't know what powers they would like or wouldn't, so we'll give a random one to each human, and let evolution figure it out. The Eldritch may have in idea of what "a terrible" super power is, but it might give a smaller amount of humans that power just in case it is actually beneficial to them, because the Eldritch probably realize they think very differently from humans. # Tech/Magic > > **Eldritch:** Let's give humans some technology > > **Humans:** Oh, hey the Eldritch gave us magical items > > > So magic wands rained from the sky one day. (The Eldritch called them a multi tool, because it conveniently had lots of features packed into it; If we gave the Eldritch a Sonic screwdriver, they would call that a magic wand.) It is powered by \_\_\_\_\_\_(It could be a essentially free power source like "power from the Eldritch dimension" (or more accurately "our science researchers can't figure it out"), or "magic" batteries regularly delivered to Earth by the Eldritch, or something from Earth — depending on your world and what limitations you want to impose on the magic wand.) The Eldritch has given more specialized "technology" (amulets, orb, etc). They don't exactly know what the humans want, so they gave them a variety. All these tools sync (imprint) with the human, and the human can just think to use it (or it has a passive effect). The tech can also use the human's "view on the world" in the sense that an amulet of anti-hurting will use that human's sense of the word hurting. # Artificially Intelligent Proxies The Eldritch scientists figured out how to make things Intelligent! (Humans call the Eldritch version of AI "animating objects" or "bringing objects to life") They then create creatures based on human art (video games, movies, fan art) and the humans wake up one day to find there is a dragon/giant wolf/pokemon/spirit animal/etc imprinted to them, waiting for orders. Our AIs have gone from knowing nothing about how the world works to imitating our speech and mastering our videogames. And our human babies have gone from knowing little about the world to being Intelligent, so it is possible for these "creatures" to do the same. Especially if they can imprint on us, and (semi-)read our minds(at least know how it's owner thinks and understands the world) Also, since the creatures are of Eldritch origin, the Eldritch can talk to the creatures, who can talk to/think to their owners and vice versa. Then the humans can give the Eldritch some our humanities' magic. > > Eldritch: > > > * This little ball can explode w/out using children screams! Now it is undetectable by children screams detectors! > * This box heats stuff up at a very exact temperature! (Compared to their traditional way by blasting it with Eldritch fireballs.) > * *Holds what we call a phone* This is useless. All it does is light up. > * *Holds tech that somehow is detrimental to the Eldritch* Oh no! \_\_\_\_\_\_\_\_. This is the worst! Why would the humans give us this? > * *Holds tech that hurts an Eldritch* Ow. Humans are mean. Let's go to war with them. > > > The monologs above should also help you think of thinks from their not-understanding perspective on why the Eldritch might give us a particular piece of their "Technology". # Summary These three ideas are some templates on which you could not only solve this particular problem, but explain a few things like magic, super powers, and exotic creatures; and some of their caveats (why does the wand doesn't/does do x? Cuz the Eldritch didn't understand us so the didn't put that feature in/ threw that feature in just in case it is helpful/ put that feature in because the Eldritch use that feature and figured we might to). (Basically it makes hand waving easier as well.) [Answer] Humans are 'killing the planet' as they see it, so let's help them get to a new one. We can't move them ourselves because they keep turning into armchairs and such, and no one's had much luck turning them back yet. According to my research into human-human understanding, if you give a man a fish, he'll basically starve to death which is an 'undesirable' outcome, but if you teach him to fish, he'll take slightly longer to die which is apparently 'desirable'. So here's the plan: We'll start by changing the properties of some of their 'base elements'. Off the top of my head, we could adjust 'uranium' so that they can use it for a reliable energy source, then - just as an example mind you - we could alter, say, 'silicon' so that the humans could do more of that 'logic' stuff with it (none of them have to know HOW it works, just THAT it works). Then, once they'd figured that stuff out (hopefully without blowing themselves up) we'd just gradually increase the speed of light until they figure out how to help themselves to move to one of the habitable planets in their 'universe'! [Answer] The only way is going with small and careful touch in order to bring change without destroying our fragile reality, like a neurosurgeon operating a brain. Thus, each operation must be as light as possible and spread on the largest time frame. The thirst thing to do would be to strengthen the human mind, even just to a small amount of people, in order to be able to withstand the cosmic horror. Next, this group of "chosen one" could establish a contact with the eldritch abominations and try to uses theirs power to change improve humanity, always with small and slow touch. [Answer] **A Breeeding Program** Interbreeding couldn't hurt, we would enjoy it, they **certainly** would enjoy it, and sanity/longevity is clearly irrelevant to the process. As ties to our dimension strengthened, unnatural selection would complete the humans' uplift. In a few hundred years, we could have some adorable pets! [Answer] **Here's the root problem with this scenario as well as all the answers here:** **Contradiction:** These beings do not follow "logic or reason", all life as we know it follows some degree of logic, even animals. **The closest relation one could draw to these beings are demons. So this post is more akin to how to justify demonic intentions as good from their point of view.** Based on the information provided you could say that demon being X realizes that his technology is powered by "the screams of unborn children" (brilliant lol), so to help power humanity they trigger events that result in the slaughter of pregnant women. (would be some fun political parallels that could be drawn with that) **The problem with that is, that follows a logical realization that because you can get power from that source so too can the humans.** **Contradiction:** Even the beings desire to "help" the humans is a logical process. To help requires you to see a problem and use your knowledge to resolve it. The only way to fix this scenario is to change the notion of "help" to interact with, having the beings perceive humans as just different beings. **Based on that analysis:** The only thing that these beings can be able to comprehend is perhaps illogical things like raw emotion without the logical understanding of the cause and effect that led to that emotion. **The hard part here becomes:** how do you influence human emotion without relying on logical cause and effect. So you cant say money makes human A happy so we make money rain from the skies. It could be that these beings can read emotion telepathically and could communicate emotion back. So the beings language is emotion. **Plausible Scenario A:** Human A **feels lusty** and services himself **then feels relief**. (minor logic) Being A associates feeling 'lusty' with relief and then broadcasts intense 'lusty' feelings in Human B causing him to relieve himself publically or go on a forced loving spree. (can replicate this with other behaviors like eating, masochism, sadism, etc. to terrible effect) **Plausible Scenario B:** Being B perceives the emotions of 'happy','proactiveness', 'depression', and 'lazyness' something like 'hi','how','are','you' and upon greeting each human sends them into a bipolar spiral. [Answer] # Cool the World In "as broad a sense as possible," the planet where these humans live is getting warmer, which is leading directly and indirectly to a great deal of suffering. This global change can be influenced in locations where there are few, if any, humans: the upper atmosphere, for instance, or the middle of the Pacific Ocean. Or the polar ice caps. ## The Mountains of Gladness Arctic/Antarctic eldritch horror stories are a grand part of the Lovecraftian tradition. Ocean levels are rising because those places are melting, and there aren't many humans there to harm. Beings-from-beyond can introduce antithermal reality warps or just pipe the entropy of the heat there into space. Sure, the scientists there will go mad, but going mad at the poles is [actually pretty normal](https://www.theatlantic.com/health/archive/2015/02/how-to-survive-winter-in-antarctica/385509/). This is akin to seeing that your ant farm is baking, and pulling the window shades, or just turning off the nearest heater. If the humans PERSIST in warming their planet, or in trudging up to the poles and losing their minds, stronger measures may be taken. Wall off Antarctica with a ring of ice mountains fifty miles high! Don't let those ants go where they're going to hurt themselves! Alternatively, use some extradimensional leaps of intuition to just go back and start cooling off the poles two hundred thousand years ago. Far fewer humans around to bother, and if they stumble through on their way across a land bridge, the carvings and shrines they leave behind as their minds collapse will just be buried in ice forever. Right? > > It is altogether against my will that I tell my reasons for opposing this contemplated invasion of the antarctic—with its vast fossil-hunt and its wholesale boring and melting of the ancient ice-cap—and I am the more reluctant because my warning may be in vain... > > > [Answer] [Scene: A vast non-space comprised of unholy materials and reified despair. The Cthulhoid horror status meeting begins] Nyarlathotep: Okay, Project Help the Humans is *way* behind schedule. Any updates? Azathoth: I reached out to one of their Mathematicians to teach him some proper non-Euclidean geometry. He just snorted and said he'd already invented it. His name was Gauss-something. The creatures simply **refuse** to put more than 180 degrees into their triangles. Shub-Niggurath: I tried to teach them the joys of mating with squamous abominations. Nyarlathotep: How did that work out? Surely that would cheer them up! Shub-Niggurath: Bah. It didn't really catch on. Well, outside of 4chan. Cthulhu: Look, we're going about this the wrong way. We know that they don't mix well with strangers, right? After all, whenever we interact with them they explode or go mad. Azathoth: Except for Gauss. He just told me to go away, he was busy. Cthulhu: Okay, okay, except for Gauss, humans need their privacy. Therefore I move that we extirpate all life in this universe, outside the Earth. Nyarlathotep: Won't they wonder why the Galactic Federation of Peace never contacts them? Shub-Niggurath: No, they have this whole equation telling them that there is no other life. They won't miss it. Plus it means that we get to go on a hellish crusade, and it *is* creeping up on lunchtime... Nyarlathotep: Sold. Let's bounce. [Answer] > > "Accounting for the fact that the literally mind-destroying influence > they tend to have on our world is completely unintentional and > uncontrollable: what methods could this species use to help (and > optionally interact with) humanity in as broad a sense as possible?" > > > They should leave. If their presence is unintentionally bad for humans and they realize it, they just should consider leaving mankind in its actual state and retire far away from them. Maybe some of them would want to leave an actual trace of their passage until the time humanity has evolved enough to accept their presence without turning crazy, but if their ultimate goal is to help humans and their presence is harmful, they have to rethink twice if staying here sending nightmarish thoughts is really a great idea. Why would aliens want to help us anyway? [Answer] **Make us like them** They can't understand us : an easy step for collaboration could be altering us *slightly* with the objective to correct that. If we're transformed enough to obey the same of rules than them, then they could maybe help us. **How can they transform us ?** It depends a lot of their abilities. there is common tropes about this. "Elevation" or "Illumination" for example, where we could learn about them and slowly become insane and detached from our mortal grounds (like a funnier version of Buddhism.) Or they could eat us. This would make us "them", sort of. As dumb as this look, this the king of concept you can find in various religions here on earth. The mean is your choice and depends of what can these edlricht buddies do. But the goal should be to drive us to their level. **And even then, how can they make us happy ?** Once we're all eldricht things, this question doesn't make sense anymore four our mortal souls. **Problems** I guess the process would kill and drive a lot people to insanity, but that's the price of progress. Is death even a problem, I can't say. [Answer] ## Experiment If you're trying to help out an unfamiliar species, it's very, very hard to get it right the first time. The best plan is to create trial scenarios to test out different possible solutions and see what works best. To do this, you will want to ensure the human's situation is as close to their natural state as possible. You're going to need to make a bunch of Earth-like planets, and isolate them from each other so that none of them are aware that they are not the original. Maybe store them in pocket dimensions. Small ones will suffice; just simulate a universe for them and they won't know the difference! Populate these imitation Earths with life scraped off the original. Now you can run all kinds of tests to see what set of circumstances produces the happiest people. Once you've figured it out, just take compatible people from all of the imitation Earths to this ideal planet (or copies of it) and burn the rest. [Answer] They could help by being a defense against an invading alien race. For example, here's how a potential alien invasion might go in such a situation: **Stage One:** Rapacious Hunger. Our assault fleet approaches the human solar system. They have limited space-based technology, and while they may put up a fight, their planet and its resources will inevitably be ours. **Stage Two:** Curiosity Morlak the Dissector's human specimen attacked and severely injured her, which is strange since Morlak had previously removed the human's internal organs. Other researchers have reported seeing transparent human children floating near the sites of nuclear explosions, but our cameras did not detect anything. Additional study is required. **Stage Three:** Concern The majority of the fourth infantry division became infected by an unknown parasite which caused hallucinations and erratic behaviour. They have defected and attacked the second and third divisions. Strike force two was ambushed by a human army two days after that same army was destroyed by sustained bombing. The initial origin of the human army is unknown, and may involve a temporal paradox. The eighth colonization ship was struck by a mountain that occluded it in the foreground of a reconnaisance image. The mountain was over 300 kilometers away from the actual location of said ship. **Stage 4:** Panic All of our colonization ships have been destroyed, which does not explain my continued presence in ship 5. I believe ship 5 may only exist on the inside. As evidence, the door in my office leads to the control room, but does not lead back. I have removed Morlak's internal organs for future consumption. I can see humans in the walls, but the scanners do not detect them. I no longer trust the scanners or computers, so I have plotted a return course to our solar system using my own blood as ink. [Answer] They could bring the Earth (and our entire solar system) into their realm so that humans can begin learning to enjoy the benefits of transcending the incomprehensible limits of "logic" and "reason" (whatever they are...doesn't matter, life will have to be better for humans without them). [Answer] Necroposting! So, a little differently from other answers, I'd assume that eldritch abominations (EA, I like this abbreviation!) are: * genuinely willing good to humanity, * *can* reason logically, it's just humans fail to understand their logic, * cannot do direct communication, as humans' heads explode if they do so. This is a classical *social Sci-Fi* premise of "willing to do good" on lesser civilisations. The determinative questions now are: * How advanced over humanity are EA? *What can they do, humanity cannot?* * In how bad shape is humanity in the opinion of EA? *How much sympathy and condolence does the view of humanity arise in EA?* --- There are multiple takes to answer these questions, the resulting options vary. I'll pick a single most interesting one. A classical Russian Sci-Fi (ha, thought, I'd miss that?) ["Hard to Be a God"](https://en.wikipedia.org/wiki/Hard_to_Be_a_God) takes somewhat a twist on that. Humans (advanced, space-faring, and communist) meet humans (in Dark Aged, bloodthirsty, bad) and *try to help* them. There is a classic dialogue, that I would like to translate and recite with insignificant cuts. It's the space guy, willing to help, speaking with a local scientist of Dark Ages, who thinks all the hope for local humanity is lost. > > "If you could give god an advice, what would you do? What should an > allmighty do such that you could say afterwards: now the world is good > and well?" > > > "Well. I'd tell him: I don't know your plans, maybe you did not indent > people to be kind and happy. Wish for this! It's so easy. Give them > enough food, enough clothes and shelter. Let famine and poverty > disappear, and also all what separates people." > > > "That's it?" > > > "You think it is not enough?" > > > "The god answers that this would not help and would not be good to the > people. The strong ones of your kind would take what I gave to the > weak ones, and weak ones would still be poor." > > > "I'd ask the god to protect the weak, to influence the harsh rulers." > > > "Cruelty is power. The non-cruel rulers loose the power and other > cruel ones take their place." > > > "Punish the cruel ones. Make it offending to the strong to tyrant the > weak." > > > "Human is born weak. A strong one emerges when no one around is > stronger than he. When cruel of the strong are punished, their place > would be assumed by strongest of the weak. And they'd be also cruel. > Everyone would be punished, I do not desire this." > > > "You know better, oh allmighty. Do so that people obtain everything > and do not take from each other your gifts." > > > "This would not do good. When they receive everything for free from > me, they'll take it for granted. They will forget how to work, they'd > loose the interest for living and turn into my pets that I would need > to feed and clothe forever." > > > "Don't give then all at once. Give them slowly a little." > > > "Slowly people would also take themselves all they might need." > > > "I see it's not that easy. I did not think about such things > previously. But... The is a way. Make people love work and knowledge > most, to make work and research their single life goal!" > > > "I could do this, too. But should I strip the humanity of its history? > Should I fake one humanity with another? Would it not be the same as > to eradicate all humans from the planet and recreate new ones > instead?" > > > "The, oh god, erase us from the earth and recreate us more complete... > Or even better: let us alone and let us pave our own ways." > > > "My heart is full of pity. I cannot do this." > > > I am not sure my translation was good enough, but this is one of the most powerful dialogues I ever read in Sci-Fi. --- Back to EA! So, assume they are like 1k years of progress more advanced than we are. Also assume they think our current state of affairs is miserable (partially for a reason). Here also goes the initial assumption that they have a heart. They are good-willing for us. (Goodwilling in the way they think good themselves – we might not agree with them!) Then they will feel the urge to *to something* to help us. They just cannot leave us alone, even if we ask them to. Because, precisely, their heart is full of pity towards us. Of course that's one possibility of many. --- Oh and about exploding heads? With technology advanced enough, they would be able to do whatever they want anyway without talking one-to-one. And it's the latter thing that causes all the insanity business, isn't it? If *any* of their tech or indirect influences makes us go crazy, they might seriously consider to leave us alone. Because, even if they mean good and are willing to help, in this concrete setting they really cannot. So they just move on with a frail heart. ]
[Question] [ Similarly to the question [How would it make sense that spellbooks or grimoires teach only one spell?](https://worldbuilding.stackexchange.com/q/91717/28789) I was thinking about typical RPG games and how to design the magic system therein. While thinking about this topic I came across the fact that weapons enhance abilities. For most weapons and your normal Fighter-type characters this makes a lot of sense to me. Of course it would be easier to fight with a sword made of material that is able to withstand more and of course the sharpened tip of a spear is better than the old dull one. A well-balanced weapon is easier to handle and reducing the weight would increase the speed with which you could handle the weapon. **But why would a staff increase the magical abilities of my mage?** Weapons are supposed to increase a characters stats as a simulation of increasing their combat performance. But most of the time *magical attack power* is a stat, too. And it gets increased like every other stat by equipping a better weapon, most often a staff. In my world magic is supposed to be the typical high-fantasy kind of magic for the normally rare magic users: * you have a mana pool that you use to cast spells * you learn spells through experience and on special occasions, such as reading a grimoire * you can throw around fireballs, create walls of earth, fly through the sky, ... * your spells do more damage the more you know about magic and how to use it efficiently - represented by a stat like *Intelligence* * *your equipped staff increases your magical attack power* I am looking for a sensible in-universe explanation as to why a staff would increase my magical attack power. This should have an analogue in real weapon usage that is represented by a set of stats as you see in most RPG games, which are increased when equipping a better weapon. I just don't know why a staff would have any impact on for example my mental stats, such as *Intelligence*, or *Magical Attack Power*, or any other specific name you might want to use that I would be able to explain the increase in magical power by equipping a *better* staff. This also means I don't know how to narrate what a *better* staff is. Is it lighter? Heavier? Fancier? Mundane? [Answer] **Wood is the best conduit** Magic is essentially extra-dimensional energy shaped through mental processes and output by whatever you have available to channel it through. You can channel magic bare-handed but the old wizards who first learned these techniques all eventually had their hands rot and fall off. While the physics of magic aren't quite known (it's not emitting photons, electrons or any modern known form of radiation) it does have definite damaging effects on living cells that channel it. Turns out that you can focus it through anything you can touch, though. You can send it out through your hat (but hats are not very good as a focus object). You can send it out through a sword (but metal is not a very good conduit and the magic comes through weak -- more on this in a bit). Through experimentation, the best conduit was found to be wood. Longer wood is better. Dead, dry wood is best and safest. The staff is simply the best magic conduit while still being easily portable. (Siege wizards prefer what is basically a telephone pole and they operate it as a team.) Now we can play with the properties of wood to come up with effects on spell usage. Maybe the [Janka hardness test](https://en.wikipedia.org/wiki/Janka_hardness_test "Janka hardness test"). I propose this: **The harder the wood, the higher the impedance and the weaker the magic.** This is a bit contrary to the norm but bear with me: The best wizard staff is actually made from balsa. The physics of magic has something to do with benefiting from a length of dead plant material as a focus, but circumference, density and rigidity all come into play. This explains why metal doesn't work well: it's too dense. You also don't do well with a giant sock stuffed full of cotton strands: you lack rigidity. Balsa wood is the perfect combination of rigid and dense and you can get the shape you want. Thinner lets you focus the magic tighter but channels less power. Thicker lets you channel more total power but with exponentially less focus. Weather wizards use a staff that's basically a balsa totem pole while assassin wizards use a staff that's more like an 8 foot long balsa wand. Most wizards settle for something in the 2-4 inch circumference range for versatility and typically settle for something like chestnut because it's hard to get a good balsa staff (and the balsa staffs are hard to maintain -- if you put a protective coating around it it just becomes part of the equation and ruins the point of using balsa). Adventuring wizards sometimes use hard wood because on a long trip, the durability of your staff is more important than it's power level. **In conclusion,** Soft wood as a conduit has a "reasonable" explanation and makes for some interesting game decisions for the wizards: softer wood is better for magic but much easier to damage through routine wear and tear (and useless as anything other than a conduit for magic). Harder wood is less powerful but the durability is handy (and in a pinch you can whack things with it). So with this soft wood idea, there is no "best" staff. There are tradeoffs. [Answer] A staff shapes your magic the same way a sword shapes your strength. Both, the swing of your arm and the swing of your sword, take energy from the very same source: your muscles. What a sword is doing is: * Take more energy over to the swing — it's harder to move it because it's heavy\*. This energy is stored in the sword's movement and is ready for future use, that is, to damage the enemy when the sword hits. * Concentrate the energy. A sword is sharp. The impact area is much smaller than when you hit with your fist, making more damage per the same amount of energy spent. * Insulate you. Breaking your fingers is something you instinctively fear. Breaking your sword is not, and it is harder to break a sword anyway. So you can hit harder and without restraining yourself. How does it translate to the staff? * Without the staff your magic flows out of you without any resistance. Thus, you can't really make a proper "push". The staff is like a nozzle at the end of a water hose, or like a sword in your hand — it makes it harder, but in a way that lets you use more energy, not in a way that makes problems. * The staff allows you to form a "needle". Without it your magic is more like a breeze. * If something goes wrong, it's your staff that breaks, not your mental health, so you can put more energy into your attack, and hit your targets harder. --- Of course you have relatively light (way under 1kg) swords that do little energy accumulation, but are great when it comes to sharpness. Or war hammers that have a large impact area, do not concentrate the energy any more than your bare fist, but accumulate much more over the swing. Similarly, I expect different staves for different purposes. And you can have staves with unique properties, just like you can have a poisoned blade — these may be permanent or require recharging. But at the base, it's all about energy, and the basic analogy seems solid. --- \* Heavy as in "much heavier than empty hand". Swords are rarely as heavy as 2 kg. Still, try to hold one if you never did, or after long break, it will feel heavy, I assure you! [Answer] Since no one else has mentioned it, a staff may also store power. So your magic user creates or gathers power either intentionally or automatically and puts that power in the staff, intentionally, automatically, or through action by the staff. In the **Dresden Files** books, Harry can cast a spell that takes a little bit of his kinetic energy from walking around or whatever and puts it in rings over a course of time. Then when he is in combat, he can release all the stored energy at once. So he intentionally cast a spell that automatically stores power in an object. In a story where one has to collect magic energy to use it later, we can think of using a staff to help with collection, storage, or both. The staff would essentially be a battery in this view. Of course, it could still be a focus object as well, at the same time as it was a battery. It doesn't necessarily have to do just one thing. [Answer] It doesn't. What it does do is let you more effectively focus those abilities. Think about it: Wielding a sword or dagger doesn't actually increase your strength or dexterity. What they do is let you more effectively bring those abilities to bear, either in a defensive or offensive capacity. In an RPG you can assume the 'stats' are really a proxy term for 'how much effect can I get out of X ability' rather than directly saying how much of 'X ability' you have. Similarly with the staffs: A staff is a tool, like a sword or dagger, for bringing your copious mental powers to bear on the world. It's the fulcrum of the mind, a lever with which a suitably prepared magic user can literally move the world. Naturally the staff must be designed to be in tune with the mind of the caster. You don't give a claymore to a rogue or a rapier to a hulking ogre: They aren't fit for purpose. Similarly with staffs: A well designed staff allows it's user to better channel and control their respective mental attributes (intelligence, wisdom, sheer bloody mindedness), and picking the right staff for the right job will get better results. In summary: They don't make you smarter: They make your smartness do more. [Answer] Spirits love wizard! Wizard nice to spirit! Oh look! That man carry a staff! Friend to wizard! Help that man! [Answer] **In Soviet Russia...** Wizards don't carry staves. However, using magic to move around is very tiring. Since wizards do not have arms or legs they tend to "persuade" a certain easily influenced species of primates into carrying them around. The wizard also allows some of their power to rub off on the primates allowing them to cast a few minor cantrips on their own. This allows the primates the delusion that their genus is capable of magic, and that they are the most powerful genus on the planet. This has a side benefit that if the other primates manage to overthrow their so-called "reign of evil" it tends to be the primate and not the wizard that gets stabbed. This is also explains why in every story where some ill-bred stable-hand finds a staff, they always turn out to be a "great wizard". [Answer] The body is, by itself, a terrible conduit for magical energy. It's not that it can't conduct the energy; it just has a nasty habit of heating up and spontaneously combusting if you go too far. Naturally, a way around this would be to use a rod of some sort of magically conductive material (say, a wooden staff with a thin gold interior) to focus your energy and enhance your "I'm not exploding yet" threshold. Another work-around might be to have multiple people and divvy up the total energy between them or their staves. Think of magic like water pressure. The human body is very weak: even a little bit of pressure and it pops (sorry for that image). A rod of precious metals or gems (if that's what you want to use) can store and focus higher magical pressures without being structurally compromised. So a staff would provide both *focus of energy* (you are emitting the same amount of energy from a smaller aperture, so more like a knife than a skimpy punch) and *storage of energy* (more pressure, less exploding) for its user. (Also a staff of precious metals would be sheathed in something natural like wood. Carrying around a thick piece of metal in your bare hands would be torture in colder regions.) Certain base materials could also have specialties in the sense that they can do one of these things more effectively: * *retain* large amounts of energy * *channel* large amounts of energy * channel energy *more quickly* * act as resistors, capacitors, or even transistors (programmable magic staff, anyone?) [Answer] Magic is a wave form. The staff is the correct length to act as a resonance chamber and wave form guide for some useful portion of the mana spectrum. Carvings, symbols, and added bits (like crystals or feathers) change the harmonics of the mana waves in some useful way. Wands would be used for shorter wave mana. Longer wavelengths tend to have better distance and area coverage capabilities while shorter wavelengths are higher energy that work better for more focused, short range applications. [Answer] A staff is a Symbol™. The origins are lost in the mists of history, but over time, wizards and staves have been associated until one is just plain incomplete without the other. "Everyone" **knows** that a wizard staff increases their power - and so, in a metaphysical placebo effect, it *does*. The staff focuses the collective will of human belief, allowing the wizard to channel their own abilities. (This might imply that a staff was more effective if there were witnesses than if the wizard were solo. It relies heavily on the thaumatology behind the magic in your world: it's less useful in a Dresden or Potter-type magic system; more useful in a *Mage the Ascension* type magic system.) [Answer] Your internal mana pool is only used to form the spell. The actual power of the spell is drawn from external sources. Unless you are in one of those settings where wizards explode when they die and their mana pool is released all at once. Thus a staff is clearly used to make the wizard able to draw mana from environment to the spell faster. There are several options that can be combined as suits the setting. Reasonably each staff would be a unique combination of traits. **Extra power** Simplest option. The staff is simply capable of drawing power from the ambient and delivering it to the linked mage. A linked staff simply increases the surface area the linked mage has to draw mana from his surroundings. **Load balancing** A mage uses mana when casting spells, but his ability to draw mana is probably constant over time. Even a limited ability to store mana in the staff would give a huge advantage for combat magic where the amount of power you can access fast is what matters. **Mana concentration** Instead of collecting mana within itself, the staff attracts it. This essentially creates a high mana field around the mage. It would in practice work much like the previous option, but would be more transparent. It would also be useful for non-combat spells as the level of mana can limit what magic can work. **Power filtering** Staff allows the mage to draw clean and stable power. It filters out spikes and "dark mana". It also filters out dips in the mana. This allows the mage to use less of the available power and time to stabilize the spell without increasing the chance of spell failure. It just makes casting spells easier and more efficient. **Flavor conversion** If there are multiple flavors of mana, the mage is probably not equally efficient at using them all. A staff could collect mana the mage is bad at and convert it to what the mage actually wants. The effect is similar to extra power and power filtering options. **Negative mana shielding** Differs from previous options only in flavor, but if the mana field fluctuates between positive and negative charge with average being zero, having a staff that has inherent mana charge would improve your ability to use magic by making mana around you more stable and charged. Sure there are many more flavor options, but I think I have covered most functional alternatives in some form. (If not in sufficient detail to be understandable.) This should at least give a usable starting point when looking for setting correct flavor. [Answer] ## A staff has nothing to do with mana A staff, or channeling artifact, is a mage's connection to the hidden energies of the world. The staff doesn't tap mana, mana is a mental resource that a mage has and regenerates. Mana itslf doesn't kill people, other than maybe the mage itself. The artifact, instead, is a type of portable power socket. Nearly no one really knows why some are better than others or what makes them trickle, the only thing that is known is that some let you sputter little sparks while others can help you unleash torrential lava Here's the reasoning: **A Mage is a Hacker:** I'll be working off this analogy. * you have an energy pool that you can use to write code (replenish with caffeine, sleep) * you learn algorithms through experience and on special occasions, such as reading stackoverflow * you can throw around exploits, animate machines, calculate secrets * your creations are more effective and take less energy the more you know about the topic - represented by a stat like intelligence * your botnet (or size thereof) increases your capacity to *crack stuff faster* **Theory of Magic** A mage has a certain amount of manas every they wake from a restful sleep. They can also top it off to a certain degree with potions. How much they have every morning depends on their overall physical health. When depleted, they turn into drooling idiots until they sleep again. Mana required to prepare a particular spell is: $$m\_s = \frac{d\_s - (k\_s p\_s)}{i}$$ where: * $d\_s$ is the difficulty of the spell (intelligence manas) * $k\_s$ is the knowledge the mage has about the spell (intelligence manas) * $p\_s$ is the proportion of how prepared the mage is to cast that spell (is his tool attuned to the spell yet?) (proportion) * $i$ is the intelligence of the mage (intelligence) If $m\_s$ requires more than a full tank of mana, the mage will have to spend more than a day preparing for it. However, a prepared spell is not a cast spell. To cast a spell, a mage needs a powerful artifact. The time it takes to cast a single instance of a spell (in seconds): $$t\_s = \frac{c\_s}{r\_a} $$ * $c\_s$ is the complexity of the spell, this depends on the choice of spell, not necessarily what the spell is supposed to do (in joules). A spell with a low complexity can be found by a mage with a high $i$, but has a considerably higher $d\_s$. * $r\_a$ is the amount of resources available to the artifact(in watt). **Conclusion about the Utility of Artifacts and their Social Impact** This means that if you have a twig you ripped off a tree, you might be able to cast a 10 sparks a second with a certain spell. However, if you have an Artifact of Mass Destruction, you might be able to launch 1e12 sparks per second with the same spell, enough to act as a propulsion system to get you to the next planet. Merlin's law says the power of newly produced magical artifacts doubles approximately every two years. Considering that the production of new artifacts is severely limited, the obvious effects this has on the increasing divide between rich and poor has many social philosophers concerned about an imminent departure from democracy and a consequent fall of the civilization in general, dubbed the "Singularity" [Answer] # They do because Wizards Believe They Do This is a little similar to @Ghotir's answer, but it is not a metaphysical placebo effect, it is an actual placebo effect. Wizards actually function by imposing their belief on the world. The fact that when a wizard says "Inflamo!" a fireball appears is because the wizard so certainly believes that a fireball will appear, that it does. The only difference between a wizard and a normal person is the shear degree of ~~arrogance~~ self-confidence they possess. They are (in a loopy near paradox) only wizards because they believe they are. A normal person can barely imagine the shear levels of hubris it takes to be a wizard. Bone deep certainty. Staffs help, because wizards believe that staffs help. Same for the robe, and the hat. And the witch and their broomstick. And all the incantations and rituals. What makes a staff better? It depends what the wizard thinks makes it better. In general it actually comes down to how hard it was to get. If the wizard payed vast amounts of money for it then it will work great, way better than a stick he just picked up. If the wizard believes that an adventurer recovered it from the tome of the ancient archmangus, then that is going to be real strong. It is about getting that really deep belief. So they takes the trappings from their master and their greater culture. This also explains why the rituals and tools of wizards from distant lands are so different, yet work well for their wizards, but not for ours. One might worry that telling a wizard that magic only works because he thinks it does, or that his staff doesn't help, might thus be crippling. But it is not so, because wizards are nessicarily the most ~~arrogant~~ self-confident people around. And so will dismiss your un-educated views. It can however, set an apprentice back months in their training. This fact may have been discovered by accident by a staff-maker, who mistakenly sent a purely ornamental pine staff to a wizard who had ordered a valuable rowan wood staff; and before they could rectify their mistake, had received a thank you note saying that "This was the most powerful staff I have ever used.", and after consulting and confirming that everyone knew pine staves were worthless except as decorative pieces, concluded his whole profession was built on lies. And then when on to make a great profit, focusing purely on the appearance of value. [Answer] My take on it is that it's the same way that a radio works better if it has an antenna but in reverse. It's a catalyst that focuses the energy and channels it. The energy is always there but if used together with a catalyst(staff), it gets focused, amplified, filtered, attuned etc. It can differ a lot from universe to universe in RPGs or other sources of fiction. In many sources, staffs and catalysts can be attuned for certain elements, usage areas, deities among more. These characteristics give the spells of certain traits or improve them in some way and reduce them in others. The same way that if you have a parabolic disk tuned for 800MHz, it will be really good at that, but may have close to none or very bad reception for the 2000MHz range. If you want to cast a healing spell, a staff attuned for healing abilities would be better than a staff tuned for destruction and death. Whereas a catalyst that is well rounded can do a bit of everything but isn't very outstanding in any area of usage. Why? There is no correct answer to how a staff should work or behave. My take on it is just as a described above with my antenna/parabola parallel. [Answer] Depends entirely on your magic system. Perhaps the magic is held in the staff itself, and the wizard is just somebody who, either through training or some innate capability, can coerce the staff to produce magical effects. In a game, this would tie-in well with your available spells depending on what staff you have equipped (different staves have different types of magic), and with pre-requisites for equipping staves (more powerful staves are also more sophisticated and harder to use). If wizardry is about manipulating some sort of environmental background magic, then the staff can act as an antenna, allowing the wizard to tune into that environmental magic more readily. Faster mana regeneration would be thematically appropriate. Or, if magic flows from the wizard, rather than being part of the environment, you can think of the staff like a paintbrush. You can finger paint, but that doesn't have the precision of carefully crafted tools. Or it can be a lever (like a sword, axe, or hammer, crowbar), amplifying your natural magical "strength" to produce bigger results. This ties in well with "+2 to fire spells" kind of game mechanics. If magic comes from either the environment or the wizard, the staff might also work like a capacitor: they slowly charge from whatever the source of magic is, and are capable of outputting that as a short high-power burst. In a game, you could represent this as the staff having its own mana bar that charges by draining the player's mana bar, then casting spells with the staff would behave similarly to Arcane Blast in World of Warcraft (repeatedly casting it makes deal progressively more damage at the cost of correspondingly higher mana usage) [Answer] The staff is an extension of the wizard himself. The effects of a staff, such as amplification, modification, augmentation, etc., are due to multiple reasons. It is a **symbol or talisman**. This gives rise to rituals such as **consecration**. Before such a ritual is performed it is but a wooden stick. All **magic is rooted in the natural phenomena** i.e. the ability to bend nature to ones will. This "**essence**" is why natural objects can increase magical capability. This essence we can refer to as "a living creature of the magical world" i.e. djinns etc. The different **types of wood** each have their own "essence", thus giving rise to the fact that certain types of wood provide **different** potencies. Trees especially are associated with various forces such as **moon cycles, planets, etc**. This is why certain plants fruit \ flower at certain times. As example the mastery of ice (cold) would be from the wood of the tree flowering in winter overcoming the cold. The "living" essence in these natural objects can also be seen in myths where the staff or wand chooses the wizard. It is because in the karmic cycle the "living essence" can experience the material world, which is typically out of reach to them as they are "locked" in the natural world. This is why the wizard and the staff become one. This also gives rise to the ability for the wizard to be "metamorphosised" into the staff (and disappear until woken or hide in plain sight). These are exceptional cases and could also result in the wizard being "trapped". The staff in Hopi tradition also serve to show experience, through carvings or rings (i.e. the chefs hat). The occasion of a wand unable to follow its destiny due to the transfer of ownership, an example from Harry Potter, is that the living force in the wand \ staff has to reach its own destiny, thus in the wrong hands seizes to function or it controls (perverts) the wielder. Note that the wood is not the essence. Wood can become void of essence and this wood does nothing, besides make for good kindling. A wizard, having a natural tendency for certain forms of magic, typically carries that staff. The *Jack of all Trades* is not common and typically those who are powerful in various forms of magic do not require "assistance" so to speak. * The staff has a mind of its own. (To follow its own chosen path) * Essences are aligned with natural forces (wind, water, etc.) * Carvings show experience; the wizard and the staff grow together. * A staff needs to be consecrated to bond with the wizard. * The staff chooses the wizard as much as the wizard chooses the staff. * A staff often reveals it's secrets when the wizard meditates upon the staff. This meditation provides a period of amplification as one meditate upon a specific item. This would relate to a specific spell. * The staff supports metamorphosis for illusionary purposes to "common" folk. * The staff has a cycle or its own of power. This is the reason why a wizard rather stays at home some days. [Answer] There are a lot of fun, inventive answers here. Just for perspective, here is some context: * The staff has long been a symbol of power We see it in the [caduceus](https://en.wikipedia.org/wiki/Caduceus) of Hermes and the [thyrsus](https://en.wikipedia.org/wiki/Thyrsus) of Dionysos, both gods with tangible magical powers. The symbol pre-dates Ancient Greece--[Thoth](https://en.wikipedia.org/wiki/Thoth), commonly associated with magic, is depicted with a staff. The symbol was formalized in the hermetic tradition, in the suite of clubs. In Tarot decks, clubs are known as "staves", "rods" or "wands", and their domain is fire. Fire fundamentally represents power in the form of energy. Note that in the Rider-Waite Ace of Wands, the staff depicted is the thyrsus: [![enter image description here](https://i.stack.imgur.com/GsVWJ.jpg)](https://i.stack.imgur.com/GsVWJ.jpg) Even Zeus' [lightening bolts are a form of staff](https://en.wikipedia.org/wiki/Zeus#/media/File:Jupiter_Smyrna_Louvre_Ma13.jpg), and constitute something of an ultimate weapon, as demonstrated by Zeus' vanquishing of [Typhon](https://en.wikipedia.org/wiki/Typhon), and it's important to note that the symbol was also associated with [temporal power](https://en.wikipedia.org/wiki/Temporal_power) and authority, which Wizards often wield. This form of the staff is commonly known as a [sceptre](https://en.wikipedia.org/wiki/Sceptre). CONCLUSION: As to why the staff increases power, it almost certainly has to do with the phallic nature of the symbol/object. Hermes was quite literally a phallic god in that his earliest representations are "[hermas](https://en.wikipedia.org/wiki/Herma)", simple columns of rock or wood *(pun intended;)* The honey-dripping thyrsus is overtly phallic. Typically feminine power is receptive (the suit of cups/[grail](https://en.wikipedia.org/wiki/Ace_of_Cups#/media/File:Cups01.jpg)) where male generative power is active. Thus the staff is a symbol of the *active* exercise of power, spiritual and temporal. --- FURTHER READING: [Hermes Trismegistus](https://en.wikipedia.org/wiki/Hermes_Trismegistus) [The Sorcerer Dionysus](http://wp.chs.harvard.edu/surs/2014/10/01/the-sorcerer-dionysus/) [The Book of Thoth](https://en.wikipedia.org/wiki/The_Book_of_Thoth_(Crowley)) [Answer] I would see magic as being all about mental discipline. Mana is an energy, similar to how muscles have energy. A magic user focuses their mana and uses that to affect the world. Focusing mana requires mentally controlling where the mana is and what it is doing. If you try and focus more too much mana you will lose control over part of it and that part will dissipate. Some magic users are able to focus more mana at once without losing their concentration so get stronger spells. How much mana you can control at once is represented by intelligence. A staff is in effect a temporary battery which can hold some of the mana without me needing to control it allowing me to concentrate on controlling the rest of the energy. So if normally I had the intelligence to control 1 joule of mana but my staff can also hold 1 joule of mana my spells will have a strength of 2 joules. A better staff is one that can hold more mana at once (capacity) or one that can hold it for longer (conductivity). This would probably be done by material so a metal staff might be highly conductive so immediately lose any energy put into it making it fairly useless. In contrast wood might have a very low conductivity so energy put in is not lost but a low capacity so it only gives a small boost. That might be why staffs are usually a wooden stick with a gemstone in them. The wood prevents energy escaping from the gemstone while the gemstone allows you to store huge amounts of energy. [Answer] The staff is only important in one very simple way, it is more "in-tune" with the world than any human carrying it can ever be. This can explain any and all possible benefits you might get from carrying a staff: * Magic is easier? Yes of course it is, magic is a natural process native to the world you are poorly attuned to, your staff acts as a bridge in such interactions and eases your way. * You feel smarter? You're actually not, but the world gives you a nudge in the right direction so you notice things you would usually miss. * Your spells seem more powerful? Because they are, your improved, bridged, attunement to the real world and its natural magical processes means that for the same effort you get a lot more bang and a lot less energy lost to resistance. "Better" staves are more deeply attuned to the world they inhabit, they're usually older and made from woods to which deep spiritual significance is attached like Yew or Rowan. The older the tree from which the wood is harvested the better, especially if the tree lives on and continues its attachment to the world as it will lead some of that to the staff even after it is removed. [Answer] Most of the time in RPG's magical staffs are tipped with some kind of crystal in them. These crystals amplify your mage's magical attack. The staff itself (not the crystal), also contribute to this multiplicative property. So a **better** staff could be made of a finer crystal and/or finer material. Adding raw magic stat to your mage doesn't really make sense much. Instead, think of it like this. Magical staffs doesn't directly **add** magic power to your mage. But **amplify** (multiply) your mage's base magic power. For instance, instead of a staff adding $+14 \text{ magic power}$, what happens under the hood is that the staff grants you $×1.14 \text{ magic power}$ (assuming your magical damage is 100) and the multiplier scales down as your magic gets stronger to maintain the static value of $14$. In real life, when you lift a 1kg dumbell everyday, eventually this would feel lighter. But it's still 1kg dumbell. The analogy is like that. So what seems to be a strong staff (+14 magic) doesn't really feel that strong anymore when you have higher base magic power. Or you could make it so, that the staff's crystals+materials have some kind of "cap" to make your magical output a static $14$. You can experiment around this idea but the gist is that the staff is a conductor of your magical energy and it amplifies instead of working like a "sharper sword". If lightning travels through a rusty metal, or a sharp metal, the output would probably be the same. But if a lightning (magic power) travels through a metal (fancy staff) versus a rubber or weaker material (poor staff) then the power gap would be much more significant. [Answer] ## You need a tool to be efficient. * You can be a world class chef all you want; but if you're going to try and chop the ingredients using a plastic knife, it won't be done expertly. * A racecar driver still needs a fast car to set a track record. * A world champion archer won't be hitting many targets with a plastic bow made for toddlers. Even a master needs an appropriate tool. This applies to pretty much every setting, including fantasy settings (e.g. the Elder Wand in Harry Potter). --- ## But which is more important? Mastery, or a high-quality tool? Let's look at all the combinations: 1. **An idiot with a low-quality tool** will obviously yield bad results. 2. **A master with a high-quality tool** will obviously yield great results. 3. **An idiot with a high-quality tool** wouldn't know how to use his tool effectively, likely yielding the same bad result as when he uses a low-quality tool. 4. **A master with a low-quality tool** will not yield the best results, but the master should be able to leverage the tool as effectively as possible (relative to the tool's quality). **In essence**, a character has a given set of skills (based on his stats), but the (lower) quality of the tool can exclude the use of skills of a higher level than the tool can handle. --- ## **How would this work for magic?** Let's take the example of a fire mage. He is able to summon flames from his hands. A better mage can create a larger flame. However, due to how fire naturally behaves, a fiery explosion moves in all directions (which means the mage is at risk when creating a large fireball) Give this mage a hollow tube of low quality. The tube doesn't *generate* the flame, but it can *guide* a flame that the mage supplies (effectively creating a flamethrower). Due to the limited quality of the tool, the mage is limited. If he supplies too much fire to the inferior tool, the tool will break or malfunction. Now give this mage a hollow tube of superior quality. The superior material means that the tube has a higher resistance to heat, which means that the mage can create a stronger flamethrower without breaking the tool. > > Even if a staff is not a physical device like the tube, the functionality may be the same: the staff does not **supply** the flame; it simply **controls** the supplied flame. A superior staff can reliably control bigger flames. > > > Staves could be made with a gem at the top, which is the "device" that controls the flames. If the fire shoots out of the gem, you could even argue that the length of a staff allows a mage to generate the fire further away from his body (thus keeping him safer for large fire blasts) > > > This means that the mage's skill is necessary. Wielding a better staff is meaningless if your first staff was already capable of handling you at your best. *My grandmother takes corners very slowly in her VW Golf. If I give her a Ferrari tomorrow, she will still be taking corners slowly, since she doesn't know how to take a corner at high speeds.* However, if you're a master with a mediocre staff, you'll be limited to a certain % of your true power. If you go beyond this percentage, the staff can no longer control the flame, thus rendering you incapable of a full-force **controlled** magical attack. *Michael Schumacher in a VW Golf is limited to the cornering capabilities of the Golf. Michael knows how to corner at high speeds, but the car is physically not capable of doing so.* If you find a superior staff, you're able to control bigger flames, so you don't have to limit yourself anymore (or at least limit yourself less). *If Michael Schumacher is given a Ferrari, he's suddenly capable of high-speed cornering. Michael's skill at high-speed-cornering hasn't changed, but the Ferrari allows him to **utilize** his skills more effectively.* --- ## Practical game stuff. You asked about RPG stats, so let's focus on how to make this system feasible. From your question, I sense a discrepancy between how you're approaching melee stats and magical stats. > > This should have an analogue in real weapon usage that is represented by a set of stats as you see in most RPG games, which are increased when equipping a better weapon. > > > I just don't know why a staff would have any impact on for example my mental stats, such as Intelligence, or Magical Attack Power > > > You need to decide what the definition of a stat is. Currently, your question is arguing two points at the same time: * Melee weapons increase your character's Strength. * Magical weapons should not increase your character's Intelligence. This is contradictory. If you argue that wielding a staff does not make you more intelligent, then wielding a sword also does not make you stronger. Do your stats express **combat prowess** (1), or do they describe **the innate skill of the character** (2)? **1. Combat prowess** In this case, Strength is really just "melee damage", and Intelligence is really just "magical damage". It would be correct to increase the stats based on the weapon that is used. Notice that if you're influencing the stats based on the equipped gear, then you shouldn't used skill checks in your game. If a character's carry capacity is decided by their Strength, then an equipped weapon should not increase a character's Strength stat (barring enchanted weaponry, I guess). Similarly, if a character requires a certain level of Intelligence for a specific dialogue option, then a wand/staff shouldn't be increasing their Intelligence (again, barring enchanted gear). **2. Innate skill** In this case, both Strength and Intelligence are fixed values (i.e. independent of the **equipped gear** - character level progression can of course still influence the stats). The stats provide a base amount of damage, and the weapon's damage is considered a bonus that gets added to the base amount; which you calculate when your character attacks. This means that you can use your stats for skill checks. You could e.g. have a character's carry capacity be influenced by their Strength stat, or have certain dialogue options unlocked for characters with at least *x* Intelligence. > > **To implement the skill/quality evaluation as I suggested in my answer, the better option here is 2.** The rest of the answer works under that assumption. > > > Let's define example characters and equipment: > > **Flater the Firemage** - Intelligence 15 > > **NubNub the Noob** - Intelligence 2 > > > **The Two-By-Four** - Staff - max Intelligence 5 > > **The Stick of Mediocrity** - Staff - max Intelligence 10 > > **The Staff of Awesome** - Staff - max Intelligence 15 > > > * When **Flater** uses the **Staff**, he can use all his magical skills. * If **Flater** levels up to Int 16 and learns an Int 16 skill, he won't be able to use the skill while he's wielding the **Staff**. * When **Flater** uses the **Stick**, he is limited to Int 10 skills * When **Flater** uses the **2x4**, he is limited to Int 5 skills * **NubNub** is inherently limited to Int 2 skills (due to his stats). It doesn't matter which weapon he wields, he won't be able to effectively use them anyway. The above example assumes that a skill cannot be used if the gear is not up to level. There are other approaches, where you still allow the use of a higher level skill: * A damage reduction. * A chance to fail, miss, or even backfire on the caster. * Durability lowers faster. You could use one of these, or a combination. Note that you could use a similar system for the opposite. Suppose Flater (Int 15) uses the **Stick**, and uses an Int 10 skill (which is on level for the weapon). Because he has more Intelligence than both the **weapon** and the **skill** require, you could give him a bonus based on how overleveled the character is: * Damage increase * Critical chance increase * The cooldown (or action point cost) of the skill is lowered --- ## Conclusion That's the gist of it. This setup should allow for both **skill** and **quality** to meaningfully factor into gameplay, in a way that characters will naturally strive to upgrade both their skills and gear equally (rather than maxing one and ignoring the other). [Answer] **Traditionally this is justified through several ways** * A Staff is a magical catalyst increasing the "efficiency" of your spell casting. * A Staff is imbued with magic power of its own that you can harness thus reducing the cost of your own spell crafting. * a staff allows one to commune better with their deity thus increasing their spell power The older or more rare the materials its crafted with increase the quality of these traits. RPG's use stats like intelligence for the staff usually so they don't have to code up or balance another stat. [Answer] > > I just don't know why a staff would have any impact on for example my > mental stats, such as Intelligence > > > Actually, there are examples of fantasy items that can indeed increase your intelligence. The Diadem of Ravenclaw in Harry Potter, for example, or tons of +XXX to Intellect items in various RPGs. I believe this can be explained in two ways. First of all, the enchantment on your magical staff can stimulate the brain activity and make you more concentrated and focused. Well, we have drugs that do this in the real world! So in fantasy world (with fireballs and stuff) the charm that makes you, let's say, less sleepy and more concentrated would be an amateur spell. Of course by equipping these artefacts *you won't know more*, but your mental capabilities will be expanded. So, in the example with fireball, you won't be able to transform it to meteor because the staff doesn't contain any knowledge about it. But you can still perform the good old fireball better because you're well concentrated and can process a dozen of magic formulas (or whatever) in your head which may be required for successful cast in your setting. The second way of explaining it is making your artefacts alive to some degree. I'm not talking about... er.... talking items, but rather 'bout something similar to the One Ring from LotR. This ring was able to change the size, make the person lose it or, on the contrary, to find it, it could even attract the wearer to itself to insanity! So magical staffs in your world might as well be that intelligent. When one equips such an item, the item somehow alters the wizard's spell-casting behaviour to make the output nicer. It guides them. Or not, in case of "bad" staff. This may also explain the "dark" artefacts. Good wizard cannot properly use dark item, because it kinda interrupts with his or her movement/casting/etc. [Answer] In addition to other answers. * Depending on magic attack type, the staff may store electricity (for lightning), poision or fuel (for fireballs), or radioactive materials for passive damage. * The staff may work as an optical system (with a gem), helping to concentrate or hypnotize. * The staff may attract or distract spirits. * The staff may be a device to communicate with gods. * The staff may be very hot or cold, giving additional damage. * The staff may allow the owner to impersonate some ancient owner of the staff, such as the king of spirits, etc, allowing the owner to give a sign to the more powerful forces, which only the staff's owner can do. * The staff may remember spells, allowing the owner not to reiterate them each time or simply increasing his memory abilities. * The staff may have some helping scheme/drawing on it, which make it easier to calculate timings and components of a spell. * The staff may work as a grounding. * The staff may be a living plant that produces some juice/substances/medicines that increase mental abilities of the owner. * The staff may work as a reconnaissance device, advising its owner about invisible dangers. [Answer] As previously stated, the quality of the tool used affects its use. Though a mage might be able to use magic without a staff, it is comparable to a swordsman who is without his sword. If you gave a swordsman a crudely made sword he would have difficulty swinging it accurately, his edge alignment might be off. If you gave a mage a weapon/tool that looked like it was made by an Ork, or maybe it was, it would not work as excellently as a well crafted one. Not including magic hanky-pankey it just comes down to craftsman ship. [Answer] Crystals and Magnifying Glass. **Crystals** allow you to split light into it's base forms - different colors. A **magnifying glass** allows you to focus light into a single point. Without the glass, you have light... with the glass, you can start fires or get rid of ants. Considering you are using powers of some sort... being able to pull out specific powers from your "pool" and then focus them into the point of your choosing are important aspects of using (and abusing) your innate abilities. Using one or the other is useful - you want fire to burn. Earth to heal. Water to wear things down. Wind to knock down your enemy tower. Using both is more powerful than just using one: You can then burn a specific enemy - instead of an area. Use water to cover your ally who's too near the fire. Wind to knock a specific person off of the tower instead of the whole tower. So, you need the right combination of construction and materials - just like metal and glass isn't anything special until you put it into the right configuration to make goggles... or a magnifying glass... or a laser. Pick the energy you want... and harness that energy to a wide area or a super fine point. [Answer] I've always imagined staffs to focus/collect/transmit magical energy in the same way an antenna focuses/collects/transmits radio signal. With a better (calibrated/aligned/materials/physical dimensions) staff, just like a better (same properties) antennae, mana collection, storage, transmission is more efficient, and works with fewer errors. With a decent wifi card and a proper wifi antennae, I can steal wifi from 2 miles away. A great wifi card is like a great mage, it knows more spells, capable of storing and using more energy. A great antennae is like a great staff. It focuses, collects, stores (antennae don't really store, just staffs), and transmits better. [Answer] **Impedance Matching** Maybe a staff is to magic what an [megaphone](https://en.wikipedia.org/wiki/Megaphone) cone is to sound. . A megaphone directs the sound, but it also does something called [impedance matching](https://en.wikipedia.org/wiki/Impedance_matching#Non-electrical_examples) which allows for more efficiency in energy transfer. When waves go from one medium to another, there is usually a reflection of part of the energy. The bigger the difference in impedance, the bigger the reflection (unless you can do some canceling of waves). If you can step the impedance down, though, then there is less energy reflected and so more energy transmitted. [Anti-reflective coatings](https://en.wikipedia.org/wiki/Anti-reflective_coating) on things like glasses use this principle. If the wood in the staff had a magic impedance the was in between the magic impedance of the wizard and the world around, or even better, had a transition between the impedance of the wizard and the impedance of the world, then it could be an intermediary that keeps some of the magical energy from reflecting back on the wizard. [Answer] The staff is magical, thus it can do anything you as the world creator want, including increasing magic powers. It's not something that is totally necessary at all of course, but the staff imagery is hard pressed into peoples minds already. Harry Potter on the other hand goes with just short wands. Similarly you could ask *why does a spell make a characters stats increase* - well, it does that because it's magic. If it had an another explanation, it would cease to be magic. The rules for it of course can vary, but whatever it is it has to fit with all the other rules in your world. If you for example use something like *Elder Scrolls* does with gems with trapped souls, then the staffs power should draw from that. That one is a clever system designed to allow crafting with clear rules and a risk/reward system, which is less important if you're not making an open world game and don't need to worry about such balance issues (and even *Elder Scrolls Morrowind* for example had huge balancing issues with creating magical items through those soul gems). It of course becomes a balancing issue in your made up world as well even if it is only for a book, so usually you would make the circumstances in which you can create such devices rare or build your stories around circumstances in which such items are common. Suppose you would have the staffs just growing in the woods and you could harness a wind spell extremely easily... well you could just create flying boats then. The important thing to remember is that it's all just made up rules - there's no such thing as universal rules for how magic works, even inside D&D stories. [Answer] > > I just don't know why a staff would have any impact on for example my mental stats, such as Intelligence, > > > Well, maybe not "intelligence". However, the staff may have an effect on how useful intelligence ends up being. So "intelligence usability" is what goes up. We just typically abbreviate that as "intelligence" as no distinction is usually needed. Some of these apparent boosts may just be deception, much like other forms of magic. Maybe the wielder doesn't actually think with more clarity or focus, but that is just the reputation a staff may have, and that reputation makes results seem more remarkable, so the staff's resulting power ends up actually being more effective even if it is all false. > > explain the increase in magical power by equipping a better staff. This also means I don't know how to narrate what a better staff is. Is it lighter? Heavier? Fancier? Mundane? > > > What you'd be looking for is a staff that is more magical. What is more magical to you? * A local McDonald's restaurant? * A toy store that causes children to be happy? * Or an entire theme park like Walt Disney World? Think about this from the eyes of a child, when such "magic" hasn't yet been dulled by finances. Which of these places seems magical to you? From what would you expect more magic to come? * A magician that pulls off his top hat, and is wearing white gloves, right by a sign that says "Forgot my wand, but I will do my best anyway", and a deck of cards on a table * A magician who did not forget his foot-long (30-centimeter-ish) black rod with white caps on both ends, and who waves the wand around * A witch, complete with pointed hat and wart, standing by a cauldron that has steam coming out of it, cackling as she speaks * A six foot (2 meter) tall wizard with a long beard, pointed hat, and a staff that is seven-and-a-half feet tall, with a glowing red gem See, even you, non-magic user, have some idea of just what is magical. Rarity can also help a whole lot. A shiny rock is better than a common stone, but a semi-transparent gem is better, and a rock that reflects and amplifies light is even better. A harness made of gold will glitter more magically than black iron. Reputation can also be good. A story can multiply its usefulness. Having a staff which has lasted a remarkably long time can be good. Even better is a weapon that has had songs written about it. If that's not feasible, at least strong rumors that it was used by a famous legendary figure from the past may suffice. Preferably if the item has been unused (and especially if out of sight) for days. No, actually, millennia would be even better. Oh, and try to throw in a name of an unvisitable location or three. The worlds of magic differ from the physical world in which we interact. Our bestest of technology relies upon electricity that is generated, stored, or transported from a source using conductive material. Magical power relies on similar such fuel or components, fictitiously in the forms of swirling lights, incomprehensible mutterings, and special ingredients, along with non-fictitious sources such as preparation, superior knowledge, concealment, and distraction. One of the strongest magical powers is awe. If you take a 4-4 piece of wood, it may have no magic. However, carve away some of that wood to reveal the image of a gargoyle's head at the top of the staff, and suddenly you have magic. The world of magic also relies on such things as blessings, hopes, dreams, secrets, hexes, and curses. Words common in magical stories involve fanciful creatures, myths, legends, and other epic tales involving incomprehensible elements such as unfamiliar abilities to exaggerate and distort normalcy into illusions that are completely unverifiable. Most importantly, lots of unfamiliarity is helpful to generate further awe. Using inhuman supernatural resources might be one method of generating such unfamiliarity, but so can easier methods like just using skills from a different culture or social circle. Elimination of the ability to use one's right mind, whether from foreign substance or disease or simply sleep deprivation, can be helpful. Less commonly reported, but possibly mysterious all the same, is if the "staff" transforms. Having it appropriately match the owner's wardrobe may also help to strike fear in enemies. So there's lots of ideas. Of course, there's certainly the possibility of combining multiple of these elements. You can also combine other elements. Tapping other powers, like the natural powers of biology, elemental powers, and even chemistry, can be very great as long as they remain unfamiliar, or at least uncontrollable. (Less familiar powers, like those involving dimensional rifts and physics belonging to other worlds, may be even better.) Even science, like being able to use a "hang glider" to move about (though only downward) through the air, can be effectively utilized magically if the verifiable, scientific element can be effectively cloaked. (What is required for "effective" cloaking may vary depending on your audience.) And if you can get trustworthy but wrong audiences to make their stories more interesting, you may even be able to upgrade your reported abilities, like upgrading from gliding to flight. Especially if the tales are old, in which case they may "reboot" and make things even more over-the-top. > > Is it lighter? Heavier? Fancier? > > > Fancier? Yes. Lighter? Heavier? Whatever is more magnificent, which may vary based on how well it matches the user(s), and what environment it is in. You might think that the strength of a legend would have little effect, but such mistaken belief would indicate a lack of much exposure to magic. And if this answer didn't seem very helpful because you were hoping for a more tangible, realistic answer, then let me remind you of how real magic really works: unfamiliarity, including concealment which often comes from successful distraction. See, all these things I was writing about *actually* are exactly what makes a magical staff, amulet, or other thing special. [Answer] I'm surprised how no one else had this idea, as it was the first thing that came to my mind. (Now comes a bit of backstory, which I think is the reason why I had that idea. You can safely skip ahead to the boldened part.) Simply think of multi-mana concepts, like in MtG. I recently installed the Extra Mana Color packages in my Magic Set Editor, and that made one essential question arise: Should the newly added colors have corresponding basic lands? You might already understand the direction this is heading towards. To make this a little clearer: I also long ago thought off a mana kind that has no lands dedicated to producing it. It can only be created as "mana of any color" or "mana of any type". To transfer it into a magic system where you're constantly surrounded by mana: **The mana around you isn't the only kind of mana.** It's merely the most basic one. Your staff has components (be it a gem or some special wood) that act as gateways towards more special mana, which is necessary for more complex spells. For some spells, stronger versions need you to resort to some of those special mana sorts as well. Of course, a staff doesn't work for all mana kinds, and not all staffs work for the same kinds. Which is the reason why a certain staff might be good for one mage, but horrible for another: **The staff that works best for your mage is the one that can channel the mana the mage is best attuned with.** For example, a river mage will draw good use from water or forest staffs, but a fire staff will be mostly useless. Oh, and also, more powerful staffs can channel more different and more unique mana, as well as more powerful spells require more kinds. To give an example, a strong Meteor might need fire mana as well as cosmic mana, where the former can be channeled already by simple staffs, while the latter requires a staff that was forged on the moon. I designed that concept with the thought in mind that a good explanation not only needs to make sense, but also must be easy to build upon. Staffs as prismatic artifacts for magic make sense, but I felt like that doesn't really make story. While, in contrast, staffs channeling mana you couldn't channel otherwise, and also channeling different mana, can easily put a mage on the search for his very own perfect staff. ]
[Question] [ **This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. ## Summary The main idea behind the "cuboverse" is that spacetime distances are measured by (something close to) the [sup norm](https://en.wikipedia.org/wiki/Uniform_norm) or infinity norm. Under this norm, spheres (the set of points at a fixed distance from an origin) are the same as cubes, hence the name. Other features that I have been able to derive from this are: * Geodesics are straight lines like in our world, but * Objects can basically only move at a certain constant speed, and only in one of eight special directions, $(\pm 1, \pm 1, \pm 1)$ in Cartesian coordinates. * There is an attractive force of "gravity", and a second cohesive force that allows primordial material to form big planet-like bodies of liquid. My question is: > > **Would planets be cubic in this universe? If not, what shape would they attain (octahedra, ordinary spheres, unstable, something else)?** > > > I would like answers based on physical reasoning and supported by mathematical calculations if possible, taking into account the relevant changes to real-world physics (see the details section below). --- ## Background I recently discovered the science fiction writer [Greg Egan](http://www.gregegan.net/). Many of his novels like Diaspora, the Orthogonal series and Dichronauts share the idea of changing one or more fundamental things about our world's physics (the number of dimensions, the metric signature of these dimensions, changes to particle physics etc.) and exploring the consequences of that change. The author keeps some [science notes](http://www.gregegan.net/SCIENCE/Science.html) online relating to these works, and after reading them I got inspired to attempt to build one such world myself. The cuboverse I imagined consists of big planets made of liquid (similar to water), one of them inhabited by a small intelligent species of eight-spiked "sea urchins", along with some other eel-like and carpet-like sentient creatures, all of them living near the surface. There are no stars in this world, so the necessary heat comes from the planet itself. I have already thought of a method of propulsion for the sea urchins and some rough details about their society. I still haven't developed the chemistry and particle physics, and I also have some questions about the biology, but first of all I would like to know whether the setting I imagined (specifically the shape of the planets and their stability) is realistic in the context of this modified physics. --- ## Details As a warning, I'm not at all experienced in exploring alternate world physics, it's my first time doing this, so some of the things I derived below could be wrong. Anyways, my basic idea is to change the Minkowski metric $$ds = (-c^2 dt^2 + dx^2 + dy^2 + dz^2)^{1/2}$$ to a $\lambda$-norm $$ds = (-c^\lambda |dt|^\lambda + |dx|^\lambda + |dy|^\lambda + |dz|^\lambda)^{1/\lambda},$$ where $\lambda$ is a very big number (I decided not to choose the sup norm itself $\lambda \to \infty$ because that would make geodesics non-unique). According to [this](https://mathoverflow.net/questions/249799/is-a-space-with-p-norm-a-finsler-manifold), with this norm spacetime seemingly becomes a kind of Lorentzian analog of a [Finsler geometry](https://en.wikipedia.org/wiki/Finsler_manifold). We can calculate geodesics (which turn out to be straight lines) and define a four-momentum vector for point particles as usual, using the Lagrangian formalism. After some calculations (I can provide details if needed), we arrive at equations for the momentum $p\_i = mc\: \gamma^{\lambda-1} \left\vert\dfrac{v\_i}{c}\right\vert^{\lambda-1} \operatorname{sign}(v\_i)$ and energy $E = mc^2\: \gamma^{\lambda-1}$, where $$\gamma = \dfrac{1}{\left(1-\frac{|v\_x|^\lambda+|v\_y|^\lambda+|v\_z|^\lambda}{c^\lambda}\right)^{1/\lambda}}.$$ Newton's second law $\mathbf{F} = \dfrac{d\mathbf{p}}{dt}$ still holds, so heuristically, for a generic set of particles at generic positions under the action of generic forces, the probability that the momenta have one or more components nearly equal to zero will be very small. Since $\lambda$ is very big, the components of the velocity vector will generically be close to $$v\_i = \pm \left\vert\dfrac{p\_i c}{E}\right\vert^{1/(\lambda-1)}\: c \approx \pm \left\vert\dfrac{p\_i c}{E}\right\vert^0\: c = \pm c,$$ as I claimed in the summary.1 This implies, among other things, that it is virtually impossible for any object to stay still: its velocity will generically be one of the eight possible vectors pictured below (which one depends on which [octant](https://en.wikipedia.org/wiki/Octant_(solid_geometry)) the momentum vector lies). [![Eight possible velocity vectors in the "cuboverse"](https://i.stack.imgur.com/4wKgj.png)](https://i.stack.imgur.com/4wKgj.png) For gravity, the most reasonable thing would be to work with a generalized2 gravitational potential $V = \dfrac{Gm\_1 m\_2}{\lVert\mathbf{r}\rVert\_\lambda}$, where $\lVert\mathbf{r}\rVert\_\lambda = (|r\_x|^\lambda + |r\_y|^\lambda + |r\_z|^\lambda)^{1/\lambda}$ is the sup norm distance between two particles of masses $m\_1$ and $m\_2$. I managed to make some calculations but the orbits look too funky, so I decided to get rid of stars and planetary systems completely, having instead a single kind of astronomical body. If planets are cubic (that's my question!), I believe the gravity near the surface would be constant. Since it is extremely easy to move a stationary object by applying a very small force, every big structure would become unstable under gravity alone, so I decided to have a secondary cohesive force that sticks particles of primordial matter together, while still allowing for some free fluid-like motion. I am not really sure how this force will look like since the chemistry isn't yet developed, so for the moment I'm forced to work with this rough description of how I want it to behave. For the moment, as a starting point I'm assuming the primordial matter consists of small hard particles, let's say ordinary spheres, and studying the collapse of a cloud of this material under gravity and a perfectly inelastic contact force (these assumptions can be changed if needed for the answer). At this point the analysis becomes more difficult, and I've been unable to find whether the planets are cubes or not. Based on the form of the gravitational potential, I would expect a "yes" answer, but the weird restrictions on the velocity make me doubt. Also, I'm not completely sure that a cohesive force will fully solve the instability problem. On the other hand, things could get complicated by relativistic effects since the velocities are close to $c$. --- Two final notes: * Just to prevent any possible confusion: my intention behind the question isn't to make a world with cubic planets, it's perfectly OK for me if the answer is "these planets can't ever exist in your world, even if you modify the gravitational/cohesive forces". The underlying intention is just to explore the consequences of the main premise; it's not necessary to keep the little sea urchins idea viable. * Although the context is worldbuilding, this is at its core a mathematical physics problem, and as such it most certainly has a unique right answer. I believe I have developed the basic physics enough for the question to be answerable with the information I provided. If that's not the case (if there's a free variable unaccounted for, or if the answer crucially needs concepts from the corresponding version of, for example, thermodynamics), please point out what else is needed and I'll try to rigorously work it out if it's feasible. --- **EDIT:** Inspired by Aric's answer I tried to make a simulation myself. I'm not very good at coding so I haven't been able to make the inelastic collisions work yet. Applying the force of gravity only, it turns out that an initially static cloud of material does seem to collapse into an octahedral shape, as suggested by some of the answers. Here are the results for a spherical slice of primordial material (color represents height): [![Collapse of matter under gravity only](https://i.stack.imgur.com/7X833.png)](https://i.stack.imgur.com/7X833.png) However, since there are some points where particles tend to clump together heavily and the simulation doesn't take into account the cohesive force that would separate them, I think there's still a good chance that the real shape is more cube-like, or perhaps something in between similar to [this](https://en.wikipedia.org/wiki/Rhombic_dodecahedron), as suggested by JBH's answer. There's still the question of stability, that I don't know how to tackle. Just for reference, I also found some [slides](http://kodu.ut.ee/~manuel/talks/finsler/2015_03_19_berlin2.pdf) online about a possible way to treat fluid dynamics in a Finsler spacetime. Most of it is over my head right now, but perhaps someone will find them useful. --- 1. - If my calculations are correct, the true speed $\lVert\mathbf{v}\rVert\_\lambda$ is actually not so close to $c$ but a bit lower for massive particles. For example, for $m = 1.8$ kg, $\lambda = 100$ and a range of kinetic energies within $(1.5 - 180) mc^2$, the speed remains between $95-97\%$ of $c$. I believe the most common relativistic phenomena like length contraction or time dilation aren't expected to play a big role though, because $\gamma$ is practically $1$ for almost all speeds, but I may be wrong on this, I haven't given it much thought yet. 2. - One can consider the analogue of a Klein-Gordon massless field and work out the corresponding "Coulomb" interaction potential as the Green function for a static field background. Dimensional analysis of the resulting integral suggests a law of the form $V \propto \lVert\mathbf{r}\rVert\_\lambda^{\lambda/(\lambda - 1)-3}$ (which is an inverse square of the distance for big $\lambda$) rather than $V \propto \lVert\mathbf{r}\rVert\_\lambda^{-1}$ (someone asked for my reasoning and I put it [here](https://www.overleaf.com/read/kywsgcjsbkgx), in case anyone else's interested). For a true gravitational force I guess I would have to look into a suitable coupling between matter and a curved Finsler geometry, and it seems there is already [some work](https://arxiv.org/abs/1112.5641) being done on this. But I don't think the specifics matter much at this point, for the moment I just want a reasonable-looking attractive force. [Answer] # TMM;DR (Too Much Math, Didn't Read): For anyone who doesn't want to go through the derivations and calculations below, here are the important points from my answer: * We're not working with the same space as normal, friendly, Euclidean space. * This means that while we can still integrate and differentiate scalar functions defined on this space, we need to make slight corrections. * These corrections can be calculated from something called the "metric tensor", which describes the curvature of space. * There are several methods that could be used to find an equipotential surface (and therefore the shape of the planet); they should require these corrections. If you want more details, read on! # Calculating the metric tensor To do certain calculations in this space, it is necessary to calculate the metric tensor $g$. This is commonly used in the case of (pseudo)-Riemannian manifolds, and plays a central role in general relativity, as I assume you're aware. To do computations involving the curvature of your space, we need to know $g\_{ij}$, the components of $g$. In the Riemannian case, we have the (smooth), non-negative norm $F$. From it we can derive the components of the metric tensor by $$g\_{ij}=\frac{1}{2}\frac{\partial^2F^2}{\partial x^i\partial x^j}\tag{1}$$ In Euclidean three-space (and in Cartesian coordinates), $F$ is the standard Euclidean distance metric $$F=\sqrt{x^2+y^2+z^2}$$ which is your case where $\lambda=2$, and you can probably convince yourself that $(1)$ yields the familiar $$g= \begin{bmatrix} 1 & 0 & 0\\ 0 & 1 & 0\\ 0 & 0 & 1\\ \end{bmatrix}$$ Here, we can extent the Riemannian definition to Finsler spaces using your [$p$-norm](https://en.wikipedia.org/wiki/Norm_(mathematics)#p-norm); in your case, we're dealing with the more general $$F=\sqrt[\lambda]{x^\lambda+y^\lambda+z^\lambda},\quad F^2=\left(x^\lambda+y^\lambda+z^\lambda\right)^{2/\lambda}$$ Going back to $(1)$, we have $$\begin{aligned} g\_{ij} &=\frac{1}{2}\frac{\partial}{\partial x^j}\frac{\partial F^2}{\partial x^i}\\ &=\frac{1}{2}\frac{\partial}{\partial x^j}\left(2(x^i)^{\lambda-1}\left(x^\lambda+y^\lambda+z^\lambda\right)\right)^{-1+2/\lambda} \end{aligned}$$ And so $$g\_{ij}=\begin{cases}(2-\lambda)(x^i)^{\lambda-1}(x^j)^{\lambda-1}\left(x^\lambda+y^\lambda+z^\lambda\right)^{-2+2/\lambda},\quad i\neq j\\ \begin{aligned} &(2-\lambda)(x^i)^{2\lambda-2}\left(x^\lambda+y^\lambda+z^\lambda\right)^{-2+2/\lambda}\\ &+(\lambda-1)(x^i)^{\lambda-2}\left(x^\lambda+y^\lambda+z^\lambda\right)^{-1+2/\lambda},\quad i=j \end{aligned}\\ \end{cases}\tag{2}$$ You can again check that this works like normal in the case where $\lambda=2$. # Volume elements So, why do we really care about $g\_{ij}$? Well, if we look at [Danijel's answer](https://worldbuilding.stackexchange.com/a/122577/627), we can see that they define the potential by $$V(\mathbf{x})=\int\frac{G\rho(\mathbf{x})}{||\mathbf{x}-\mathbf{x}'||}d^3\mathbf{x}'\tag{3}$$ where $d^3\mathbf{x}'$ is the volume element; notice that we've allowed $\rho$ to vary, as it would for a real planet. For Cartesian coordinates in Euclidean space, $d^3\mathbf{x}=dxdydz$. However, this is not always true. Indeed, in [the general case](https://physics.stackexchange.com/a/65040/56299), $$d^3\mathbf{x}=\sqrt{|g\_{ij}|}dx\wedge dy\wedge dz\tag{4}$$ where $\wedge$ denotes the [wedge product](https://en.wikipedia.org/wiki/Exterior_algebra), and we see that we need to calculate the determinant of $g$, $|g\_{ij}|$. (Note again how $\sqrt{|g\_{ij}|}=1$ for Cartesian coordinates in Euclidean space.) The calculation of the determinant is ugly, and I won't do it here because there's little point to it. I assume symmetry allows it to be written somewhat neatly, though. # Gradient As has already been noted, the surface of the planet should lie on an equipotential surface, that is, one where $|\vec{\nabla}V|=0$. The familiar Euclidean gradient is $$\vec{\nabla}=\left(\frac{\partial}{\partial x^1},\frac{\partial}{\partial x^2},\frac{\partial}{\partial x^3}\right)\hat{x}\_i$$ for generalized coordinates $x^1$, $x^2$, and $x^3$, which are are $x$, $y$ and $z$. It should come as no surprise, however, that this fails for non-Euclidean spaces. [In the more general case](https://en.wikipedia.org/wiki/Gradient#General_coordinates), $$\vec{\nabla}=\frac{\partial}{\partial x^i}\cdot g^{ij}\sqrt{g\_{jj}}\hat{\mathbf{x}}^i\tag{5}$$ for unit vector $\hat{\mathbf{x}}^i$, and again $g\_{ij}$ plays a role. # Poisson's equation and the shell theorem Here, of course, is the problem - and it's been bothering me for about a day now. The core question you're asking here involves determining the potential corresponding to a given density distribution. We can do that easily enough in flat space by solving [Poisson's equation](https://en.wikipedia.org/wiki/Poisson%27s_equation); the solution can be found through $(3)$. Okay. **But does Poisson's equation look the same (or even similar) in this Finsler space, and can we solve it the same way?** The answer may be that it doesn't. In general relativity, on a Riemannian manifold, holds in the Newtonian limit of the Einstein field equations. However, it's not clear that we can make the same assumption in Finsler space. Let's say Poisson's equation holds in some sort of form (here, I have set the appropriate constants to $1$): $$\nabla^2V=\rho\tag{6}$$ Then, indeed, $(3)$ holds in general, in some form, again with the appropriate volume element. Now, what I'm curious about - and I've talked about this in chat a bit - is the answer to [a question posted by Dietrich Epp](https://worldbuilding.stackexchange.com/questions/122564/would-planets-be-cubic-in-my-cuboverse/122603#comment378616_122582): Is the gravitational field outside a "sphere" identical to that outside a point particle with the same mass (the [Shell Theorem](https://en.wikipedia.org/wiki/Shell_theorem))? If so, your given equation for the potential holds for a planet, and $$V(\mathbf{x})=\frac{Gm\_1m\_2}{||\mathbf{x}-\mathbf{x}'||\_{\lambda}}$$ If not, we need to integrate $(3)$ properly before making any assumptions about the form of the potential. At any rate, I'd be interested in seeing a proof that a version of the shell theorem (or a version of [Birkhoff's theorem](https://en.wikipedia.org/wiki/Birkhoff%27s_theorem_(relativity))) holds. # A path to a solution I don't have an answer to your question yet. There are a couple of ways you could go find an equipotential surface: 1. Muck about with various surfaces and find one where $(\text{3})$ is constant for all $V(\mathbf{x})$ on the surface. 2. Set $|\vec{\nabla}V|=0$ and find the resulting surface. 3. Set $V(\mathbf{x})$ equal to some constant $C$ and again find the surface. The third method seems like it should definitely work in the case of a Euclidean metric, for your chosen potential. I can't say for sure whether it works for all relevant Finsler metrics (and I suspect it doesn't), so I won't claim that the general case works just yet. # The naive third case Okay, so let's set $V(\mathbf{x})=C$ for some constant $C$. Here, I assume that your potential is applicable for a planet. We then have $$||\mathbf{r}||\_{\lambda}=\frac{GM}{C}\implies\left(x^\lambda+y^\lambda+z^\lambda\right)^{1/\lambda}=\frac{GM}{C}$$ Therefore, we're left with $$z^\lambda=\left(\frac{GM}{C}\right)^{\lambda}-x^\lambda-y^\lambda\tag{7}$$ Interestingly enough, as $\lambda\to\infty$, this becomes a cube! ## References: * [Shen 2000](https://arxiv.org/abs/math/0011136) * [Lecture notes by Matias Dahl](https://math.aalto.fi/~fdahl/finsler/finsler.pdf) * [Popvici 2017](http://dergipark.gov.tr/download/article-file/435094) * [Busemann 1950](http://math.uni.lodz.pl/~sajmonw/mathbooks/Busemann,%20The%20Geometry%20of%20Finsler%20Spaces.pdf) [Answer] # No The necessary condition for a liquid body to be in a gravitational equilibrium is that gravitational potential should be constant over its surface. For the cube with density $\rho$, by integrating $$ V(\mathbf r) = \int\_{cube} \frac{G \rho}{\lVert \mathbf r - \mathbf r' \rVert\_\lambda} d^3 \mathbf r' $$ for various locations $\mathbf r$ on its surface, it is easy to see that e.g. the middle of a face of the cube is deeper in the gravitational well of than a point on its edge (or vertex). The correct shape *probably* isn't a sphere, which can also be checked using the same method, but it is harder to integrate, so I didn't do it. It is still an interesting mathematical question what would be the correct shape. [Answer] As Danijel has pointed out, the question can be reframed as "what is the shape of the equipotential surface under this force law?" There are further two different ways to view the results: the external perspective, where we see what shapes these "planets" map onto if we overlay them on our normal Euclidean space, and the internal perspective--what would they "look like" to someone embedded in the same metric? The external perspective is a lot easier to figure out. You just calculate the shape of the equipotential surface in Euclidean space using a different force law. Finding the exact shape is complicated, but the broad strokes are fairly clear: force reduces over Euclidean distance more slowly along the octants than it does normal to the faces, which means the potential at equal Euclidean distance is higher along the octants than the faces... and so the equipotential surface ends up dimpled *inwards* along the octants, rather than poking out to form cube vertices. If you actually wanted cubical worlds, you'd need a force law that decreased *faster* along the octants, not slower. Exploring the internal perspective is considerably more complicated. Honestly, I'm not even certain what the best way to approach it is; trying to imagine living in a lambda-norm world breaks my brain! As a first step, I'd probably try to investigate the local curvature of the equipotential surface under that norm; is it roughly uniform, in which case the inhabitants of this universe would likely perceive their worlds to be approximately smooth, like we do ours, or does it have regular variations that would correspond to edges and vertices? With a little more formalizing (which it seems you are perfectly well qualified to do), that's a question you could probably take to the Mathematics StackExchange and get much more productive answers. [Answer] *My answer isn't going to be anywhere near as in-depth as your question but I'm happy to supply a few inputs.* --- First, I'm going to take a look at your particles: **1. Particles can only move at one constant speed.** **2. Particles can only move in six directions.** (Or four in my 2D model.) **3. Particles have "gravity".** I'm going to imagine two particles in a two-dimensional plane for now: [![enter image description here](https://i.stack.imgur.com/MS1oZ.png)](https://i.stack.imgur.com/MS1oZ.png) We could represent gravity as a vector from one particle to another, so the top left particle would have `(3,-2)`. To make this pull weaker with distance, we can multiply the vector by the reciprocal of its magnitude: [![enter image description here](https://i.stack.imgur.com/n4p4y.png)](https://i.stack.imgur.com/n4p4y.png) If there were other particles, we'd have to calculate the force vector for each. The resultant gravity would be the sum of the vectors, which in this example is just `(3/√13, -2/√13)` Now, the particle can only move in one of the four directions in this 2D example, so let's take the vector component with the largest magnitude: `x = 3/√13` and move one square in that direction. The result would be that both particles zigzag towards each other until they meet. At this point, two things can happen: * The particles stop moving. This violates your rule that the particles "basically only move at a certain constant speed". You could change this rule to *The particles are either stationary, or moving with a set speed*, having a binary value for their velocity, OR: * The particles oscillate between their two positions. This means that the particles will be fixed into an "orbit" around each other that lasts 2 time ticks, however it lets them pass through each other. This can be explained by having the particles move from one point in space to the adjacent point without interacting with, or passing through, the space between. This is all fun and dandy until you hit a situation like this: [![enter image description here](https://i.stack.imgur.com/19GxU.png)](https://i.stack.imgur.com/19GxU.png) Provided there are no other particles in the entire universe, these two particles will have a force vector where two or more components are equal. In this case, how does the particle choose which way to go? * **Solution 1: Randomly decide** Let's forget all of those [God Does Not Play Dice with the Universe](https://images.ecosia.org/MDWJqfSQcgeFzIP3OyVEww8xnf4=/0x390/smart/https%3A%2F%2Fs-media-cache-ak0.pinimg.com%2F564x%2F8e%2Fb4%2F91%2F8eb49119a5b05c3db1ce1edd7e9b3a10.jpg) shenanigans, because we can't simply "move diagonally" in this system. If there's two possible directions to move in, each with an equal likelihood of occurring, one of them must happen. Just randomly pick one of the tied directions and go that way. * **Solution 2: *Quantum stuff?*** Just make the particles go into superposition. Ya know, go both ways at once. Why not? After one time tick it'll look like this (particles now coloured red and blue) [![enter image description here](https://i.stack.imgur.com/CvuzW.png)](https://i.stack.imgur.com/CvuzW.png) Now there's three possible positions for each particle, with probabilities of `25%, 50%, 25%` of existing in each position. [![enter image description here](https://i.stack.imgur.com/kpo0O.png)](https://i.stack.imgur.com/kpo0O.png) Now we have to perform a measurement, since each superposition may be colliding with something. And the probabilities of both red and blue existing in a specific position is a binomial distribution! That's fine, just randomly decide which of the paths the two particles took... But wait! What happens if they both end up on the same square? Well, SOMETHING would have to happen. I can't for the life of me figure out a way to work around this. Maybe you can, I don't know. The advantage of Solution 2: *QUANTUM STUFF???* is that it allows the superimposed particles to interact with other, third party particles that may cause a measurement to happen early. This would, again, cause two particles to exist in the same place. The advantage of method 1: No nasty probabilities. --- **Okay, so you talked a lot about gravity. Stuff can clump together. But nothing can orbit without momentum!** Momentum can be represented as another vector. Each time tick, The resultant force of the gravitational attraction to every other particle in the entire universe is added to the momentum of the particle, forming a new momentum vector. Now, instead of moving in the direction of the strongest pull of gravity, the particles move in the direction of the strongest component of their momentum vector. **Now, all of this is great, but does it work?** I will attempt to simulate this in Python and then update my post in due course. My predictions: * Unless I find a way to prevent multiple particles moving into the same space, the whole system may collapse into a singularity. * If momentum works correctly, there MAY be some form of orbital mechanic possible. * Clumps of particles may form. If they do, they will either have a roughly circular shape, or may create "crystal" shapes such as this: [![enter image description here](https://i.stack.imgur.com/FdUbZ.png)](https://i.stack.imgur.com/FdUbZ.png) My theory is that a particle may be more likely to move towards another body of particles if it is vertically or horizontally in line with it, resulting in protrusions from the clump along the axes and possible diagonal edges. --- ## The simulation --- Here's what I've got so far: ``` import pygame import random (width, height) = (1000, 1000) screen = pygame.display.set_mode((width, height)) class Particle: def __init__(self): self.position = (random.randint(-50, 50), random.randint(-50,50)) self.momentum = (random.randint(-10, 10)/10, random.randint(-10,10)/10) def move(self, positions): resultant = (0, 0) for position in positions: vector = (position[0] - self.position[0], position[1] - self.position[1]) magnitude = (vector[0] ** 2) + (vector[1] ** 2) if magnitude == 0: return resultant += (vector[0]/magnitude, vector[1]/magnitude) self.momentum += resultant if abs(self.momentum[0]) > abs(self.momentum[1]): self.position[0] += self.momentum[0]/abs(self.momentum[0]) elif abs(self.momentum[0]) < abs(self.momentum[1]): self.position[1] += self.momentum[1]/abs(self.momentum[1]) else: if random.randint(0, 1) == 1: self.position[0] += self.momentum[0]/abs(self.momentum[0]) else: self.position[1] += self.momentum[1] / abs(self.momentum[1]) def render(self): pygame.draw.rect(screen, (255, 255, 255), (int((self.position[0] * 10) + 495), int((self.position[1] * 10) + 495), 10, 10), 0) def run(): screen.fill((0, 0, 0)) particles = [] for x in range(10): particles.append(Particle()) running = True while running: for event in pygame.event.get(): if event.type == pygame.QUIT: running = False positions = [] for particle in particles: positions.append(particle.position) for particle in particles: particle.move(positions) for particle in particles: particle.render() pygame.display.flip() run() ``` It either takes incredibly long to calculate the next frame, or it doesn't work. I haven't worked that out yet... [![enter image description here](https://i.stack.imgur.com/We0R4.png)](https://i.stack.imgur.com/We0R4.png) [Answer] Edit: I think I misread the question, but the gist is: If your cube shape is equidistant from the center-of-mass, and gravity depends on distance, then the shape of the planet will be all "same-distance" from the center. --- A good first approximation is an octohedron. Why is it an octohedron and not a cube? It's because your universe has 6 special directions and they correspond to the 6 points of the polyhedron. In this co-ordinate system, all points on the surface of an octohedron are equidistant from the center of mass. [![enter image description here](https://i.stack.imgur.com/N4EKN.png)](https://i.stack.imgur.com/N4EKN.png) [![enter image description here](https://i.stack.imgur.com/LaDzn.png)](https://i.stack.imgur.com/LaDzn.png) [![enter image description here](https://i.stack.imgur.com/N9Set.png)](https://i.stack.imgur.com/N9Set.png) It's worth noting that cubes and octohedra are "dual polygons" and the faces of one correspond to the points of the other. [Answer] I wish I had more time to play with the math, but let's use some logic. * Velocity vectors must work in both directions. If your particle can only move in an octant, then gravity can only draw in an octant. This suggests... 1. That gravity is functionally discrete. Unlike in our universe, where we could simplify and simulate this issue with two ball bearings that roll around each other's surface continuously with equal forces of gravity at any point, yours looks like the diagrams below. 2. The force of gravity over distance is wild wonky. Rather than simulating it as a growing sphere of diminishing influence, it's more like a simple star you'd plop on top of a Christmas tree. The "arms" of the star would diminish with the square of distance, but between the arms it would diminish with something more like the bazillionth exponent of distance. Random attraction in your universe would be a much, much slower process. Let's look at the pretty pictures, which I ruthlessless appropriated from your post. I hope you don't mind. **The weakest gravitational force, the single-vertex force** [![enter image description here](https://i.stack.imgur.com/fOaQK.jpg)](https://i.stack.imgur.com/fOaQK.jpg) **Double the gravitational force, the dual-vertex force** [![enter image description here](https://i.stack.imgur.com/WBsNU.jpg)](https://i.stack.imgur.com/WBsNU.jpg) **The strongest gravitational force, the quad-vertex force** [![enter image description here](https://i.stack.imgur.com/Ns52h.jpg)](https://i.stack.imgur.com/Ns52h.jpg) Unless you change the various lowest-energy-state/conservation-of-X rules in your universe, your planets will be formed predominantly by particles snapping into the quad-vertex force position. They can form in the single-vertex condition, but any little "bump" will slap them into one of the two higher gravity conditions, eventually into the quad. At first blush, this would suggest your planets are shaped like that Christmass star or an 8-pointed pinata. [![enter image description here](https://i.stack.imgur.com/xEG7C.jpg)](https://i.stack.imgur.com/xEG7C.jpg) Except there's all those spaces in between with 6-vertex and 8-vertex connections... In the end, I believe you'd get planets that are roundy-with-corners. Think cube balloon, where the sides bulge from the internal pressure: [![enter image description here](https://i.stack.imgur.com/raZhx.jpg)](https://i.stack.imgur.com/raZhx.jpg) **Finally, a word about orbits** I predict that all your orbits will be eclipical due to the descrete nature of the gravity vectors. You may have small/light objects that orbit on an elliptic plane tilted 45° to the ecliptic, but that's the weakest gravitational path. I also suspect you won't have much in the way of planetary axial tilts (0°, 45°, 90°). If you'll fogive the pun, those gravity vectors will have a tendency to keep things "boxed." [Answer] Material science answer; it'll always be a "gravitational sphere" (a smooth round object with a gravitationally flat surface) because that's how stable mass assemblages always come to rest, lowest potential energy state. For the sake of clarity that's "smooth", "round" and "flat" on a planetary scale. I'm not at all sure what a gravitational sphere actually looks like to a human equivalent observer in the proposed universe but looking at it through the euclidean filter of our physical senses I'm pretty sure it'll still be a sphere. [Answer] I'm going to try a short and simple answer. I assume gravity works similarly to our universe, except for the calculation of distance. A gravitationally stable form is where the surface points are equidistant from the center. If some points were farther from the center than others, smoothing them out would reduce the gravitational potential energy. In the metric you're using, the distance is the largest of the x, y, and z differences. If we take a radius of 3 for an example, the equidistant surface is that which is 3 away in one dimension, and no more than 3 in any other dimension. That gives us a cube. If the distance was x + y + z, we'd get an octahedron, which I'll leave as an exercise for the reader. [Answer] Your movement rules... are very confusing, what with the eight special directions and the tendency of matter to constantly travel at the speed of light along one of them. If I'm even understanding that correctly. So, for the remainder of this answer, I will assume that the "cohesive force" that you mention causes primordial particles to group up into clusters ("atoms") that can move more freely. The primordial particles within these atoms bounce around in the eight special directions at the speed of light, but the whole atom can move in any direction at any speed, depending on what fraction of the primordial particles therein are moving in each of the special directions. As a side note, this actually reminds me of the strong nuclear force. Protons and neutrons are chaotic messes of quarks and gluons bound together by the incredibly strong forces of quantum chromodynamics. Smaller hadrons occasionally leak out of them and can interact with any other nucleons that happen to be nearby, resulting in the forces that bind atomic nuclei together. The atoms that I describe above are chaotic messes of primordial particles held together by an incredibly strong force. Individual primordial particles (or, if you prefer, smaller "atomic" clusters) could occasionally leak out of them and interact with other nearby atoms, resulting in something analogous to either nuclear physics or chemistry. Anyway. With that out of the way, let's look at gravity. You give a definition right in the question: $$ V = {G m\_1 m\_2 \over ‖\mathbf{r}‖\_λ} $$ which decreases with the inverse of the sup norm of the position, presumably in analogy with gravitational potential in our universe, which decreases with the inverse of the Euclidean distance. Thus, escape velocity will work the same way, and orbits should at least exist, although their shapes will be pretty funky and may or may not be stable. The answer to the question of "what shape will a liquid planet have" is always "whatever shape has constant gravitational potential across its whole surface." For a planet consisting of a volume of massless liquid, this is quite simple: It's a cube. In the sup norm, the entire surface of a cube is the same distance from its center, and the sup norm distance is exactly what matters here. However, when dealing with planets, point masses covered in massless liquids make for a bit of an oversimplification. It works in our universe, thanks to symmetry and Gauss's Law, but the physics here are very different. To figure out what planets in this universe actually look like, we need to dig a little deeper. Specifically, we need to figure out how gravity actually works. The force, I mean; not just the potential. For point masses, this is fairly simple: the direction is straight down the potential gradient, and the magnitude is equal to the slope of that gradient. Thus, the gravitational force between two point masses will always be in one of the *six* Cartesian cardinal directions. That is, perpendicular to the faces of a cubic planet. And the magnitude will, as in our universe, drop off with the inverse square of the (sup norm) distance. With that, we can start to explore the gravitational fields of things that aren't point masses. Note that for computing the gravitational force along each axis, we only care about matter in a 45-degree pyramid centered on that axis. If you imagine a cube broken up into six identical square-based pyramids, such that the apex of each is at the center of the cube, each pyramid gives the volume in which matter can pull the center of the cube in one of the six axial directions. ... I'm not sure if that description made any sense at all, but no matter. Onward! Case study 1: An infinite, flat, zero-thickness plane of uniform density, perpendicular to one of the axes. An object on either side of the plane will feel a gravitational attraction toward it. Specifically, it'll feel the gravity of a square region of the plane, with side length equal to twice the distance to the plane. The gravitational force will be proportional to the area of the square (which goes up with the square of the distance) divided by the square of the distance... so the plane creates a uniform gravitational field on either side of it. Just like in real life, with out Euclidean norms. This also means that infinite planes with non-zero thickness will also behave the same way. Case study 2: An infinitely long, infinitely thin rod, aligned with one of the axes. An object will feel the gravity of a section of this rod with length proportional to the sup norm distance to it- and, given the inverse square law, this results in a force of gravity proportional to the reciprocal of the sup norm distance to the rod. Again, much like real life. Case study 3: A solid cube. At extreme distances, this will look much like a point mass, but this question is asking about the shape of a liquid planet, so what really matters is the surface. At the center of each face, gravity will point directly toward the center, perpendicular to the face. At the center of each edge, half of the mass of the cube will be pull along one axis, while the other half will pull along another axis, resulting in a net force at a 45-degree angle. Points near the edge will experience only marginally different gravity, so liquids will flow down from the vertices and edges and pool up in the centers of the faces. Thus, uniform-density liquid planets won't be cubes. Case study 4: Maybe an octahedron will do it, then? At each vertex, the entire mass of the octahedron will pull matter in the direction of one of the axes. At points near each vertex, almost all of the mass of the octahedron will exert a force in that same direction... once again, causing liquids to flow toward the center of the nearest face. So, clearly, liquid planets in this universe will be neither cubes nor octahedra. They will be a smooth surface of some kind. The gravitational field in the vicinity of an object with finite density (i.e. if we exclude things like point masses and the zero-thickness planes and rods discussed above) will always be continuous and differentiable; therefore, for its surface to be perpendicular to its own gravitational field, its surface must also be differentiable. So what shape will the planets be? Spheres? Maybe. I don't know. They will have at least as much symmetry as cubes and octahedra, I can tell you that much. In any case, whatever shape uniform-density planets turn out to have, the denser the planet's core, the more cube-like it will be. In the limiting case where all of the planet's mass is concentrated in a point at its center, the planet will be a perfect cube. [Answer] While not fully related, I felt like adding what the GBE would be with such cubic planets. -G \* ((Mshell \* Minterior)/r) Which would, assuming r = a/2, change to: -G \* Integral(Lower: 0, Limit: R) \* ((2r)^3)\*p)((24r)^2)\*p)/r) which goes to: (4608Gr^5p^2)/(5) Plugging in for density: (72GM^2)/(5r) Joules of Gravitational Binding Energy. If one just uses normal side length: (36GM^2)/(5a) Joules of GBE. Please alert me if I did some of my math wrong. [Answer] **Yes** This is, in fact, only a matter of perspective (as well as altering the way gravity works). If distance is defined as you suggest you could even argue that our earth is also a cube if that is the way that you actually perceive distance. What we're really talking about is the definition of a metric, and what you're describing is called a Taxicab metric as opposed to a euclidean metric. And by stating that gravity uses the Taxicab metric instead of a euclidean one (gravity would operate by measuring the distance the Taxicab way), that would make our earth into a cube (by euclidean standards), but they might still call it a sphere because by the taxicab metric those things are the same. This also contradicts your other premise that this space follows Minkowski space principles, as this space is defined from a euclidean basis. So maybe I'm misunderstanding your premise. One problem you will face is that of orientation (what's the cause of a certain direction being a cardinal one). Then vertices of each of your cubic planets will actually be on the 8 cardinal directions. So, if an object is limited to movement only in those directions, they couldn't move along the surface of the planet, they would need to go in the direction of one of the vertices of the planet they are on away from the surface, and then "fall" back down along another vertex's direction. ]
[Question] [ The setting is the medieval ages, vaguely European. No magic exists except what is explicitly stated in the question. The judicial system is similar to historic examples, with the head-of-state directly overseeing cases of sufficient magnitude to warrant his or her direct attention. In this world there exists a small kingdom; three large cities and then the towns and communities that support it. One day the king receives a Truth Stone as a present. Whenever someone holds this Truth Stone and (verbally) speaks the stone will use the holder's own mind to judge any intended deception. If he or she remains silent, the stone will not react at all. * If the speaker is intentionally speaking falsehood or is intentionally misleading or misdirecting, the stone will glow red. * If the speaker is intentionally speaking the truth, and is not intending to mislead or misdirect, the stone will glow blue. * In any situation where the above two condition groups can't be determined *from the holder's/speaker's point of view* the stone will do nothing at all. The stone does not account for cases of insanity, misunderstanding, or any other situation in which the speaker/holder *believes* themselves to be speaking truthfully but is in fact in error. If he believes the world is flat and says it is round, the stone will glow red. If he believes the world is round and says it is flat, the stone will also grow red. If he believes himself to be a unicorn, and says that he's a unicorn, the stone will glow blue. Further the stone divides phrases based on the speaker's views on the division of phrases. If somebody says: "I am a man, a carpenter, and have never eaten meat" the stone will *probably* evaluate each statement separately (going dark momentarily between each statement), but may not if the speaker sees that as a collective idea (such as if he was denying being part of the Guild of Female Carnivorous Stone Masons). If a person was taught different meanings to terms, such as "guilty" meaning "innocent" the stone will evaluate it based on the speaker's/holder's understanding of the term. To clarify: every reaction by the stone is based on the speaker's/holder's views on the statements that he or she just spoke, and has no direct dependence on the actual reality. --- When there exists effectively a polygraph test that is as-perfect-as-possible (like the polygraph, targeting *belief* of truth) is injected into the legal system, and where the accused's belief of innocence can absolutely be determined, how would such as stone force the legal system to evolve, and how would it force criminal activity to evolve? [Answer] ## Scenario 1: The King declares: "I have decided to use the Truth Stone to root out any and all corruption in my administration." Stone vanishes from behind 5 supposedly locked and guarded doors, with nary a trace the very next day. King Terren **reloads**. ## Scenario 2: The King declares: "I have decided to use the Truth Stone to root out any and all cheating spouses in my kingdom." The Kingdom descends into complete chaos the next day, as 1 in 4 spouses know they will be revealed as cheaters. King Terren **reloads**. ## Scenario 3: The King declares: "I have decided to use the Truth Stone to root out any and all common crime in my kingdom." All criminals now decide to never leave any witness behind, since any and all evidence leading to them will now lead to a conviction. Murder rate soars. King Terren **reloads**. # Scenario 4: The King picks up the stone and declares: "The sentence I am saying currently is a lie." According to a survivor, the stone reportedly turned an [impossible](https://en.wikipedia.org/wiki/Impossible_color) bluish-yellow color, grew hotter and hotter over the next few hours, and finally detonated with a light so bright and a thundering noise so loud that it was seen, heard and felt in the neighboring kingdoms. The entire court, the royal palace, the citadel, the city walls, all the city houses, as well as the surrounding countryside were devastated for many miles. A giant mushroom of smoke hung over the ruined city for hours, and winter arrived early that fall, bringing famine and foreign invasion to the battered kingdom. King Terren **reloads**. ## Scenario 5: After a minute's thought, the King gracefully thanks the stranger for the gift, then orders all present in the room to be killed by his guards, then has all the guards murdered in turn. The Truth Stone remains the highest guarded state secret for the next century, as the kingdom expands greatly, with the king and the following 3 kings using the truth-detection method for ferreting out spies, double agents and untrustworthy allies and vassals, thus gaining **an unmatched strategic advantage** over any and all rivals. [Answer] How about this? The stone goes into a church/temple/palace. The accused in any trial has the right to *demand* a *Trial by Stone* instead of the usual legal process, but only before that process starts. * The accused will be transported to the stone. This can be a slow and degrading route at the king's expense (chain gang) or a faster one paid for by the accused. * The accused will be asked three questions: "Are you guilty of *whatever*?" "Did you call for the *Trial by Stone* in good faith?" "Are you a loyal subject of the king?" If the stone is blue three times, the accused is free. If it is not blue three times, the accused has wasted the king's time and his head will roll for that. An alternate option would be to have the stone "tour" through the kingdom and check the inmates of local jails, but doing that would mean there has to be a jail to start with. Locking up people as punishment is a rather new invention. Peasants need to work the fields, not sit idle. [Answer] The real problem is that the stone does not actually force you to speak truth. So when you speak a half-truth or a misleading truth it will still identify it as a lie. A clever person could still work their way through this by only saying things intended to mislead or deceive. The listener would still have to interpret which parts are a lie. For example, I and my accomplice commit a crime. The witness only saw me at the crime scene. I am asked if I committed the crime. The truth is that I and my buddy committed the crime. In order to protect my accomplice, I claim that "I" committed the crime. The stone shows I am misleading them. Everyone now believes that I did not commit the crime. They may wonder why I choose to lie about it but the more guilty I say I am, the more innocent the stone makes me look since I am intentionally misleading them. This is just one example. Deceive and manipulate with every statement you make. At worst you will muddy the waters and sow confusion. At best, if the questioning is not extremely careful, you can inversely prove your innocence in your attempts to mislead them when admitting the exact nature of your guilt. A few incidents like this and people will wonder if the stone really works or whether it is really some kind of political tool the king uses to make anyone he wants appear to be guilty of something so he can execute them. Edit: I just wanted to clear up some things brought up in the comments. First, the base assumptions are: 1) No one but the accused actually saw the exact moment the crime was committed. 2) The accused was seen at the scene of the crime (perhaps even doing something very suspicious) If there is other evidence then you really aren't making a conviction based on what the stone indicates. You are just using it to confirm. However, in this case you would probably be found guilty even without a magic stone. So I am not talking about that. Second, I am not suggesting that lies and deception can always get you off the hook. That is definitely at one end of a scale of different possibilities. If you tell a lot of lies, people might just assume you are guilty even if they aren't sure exactly what you are hiding. However, that won't help them find the loot, identify your accomplices, or force you to incriminate yourself on additional items they don't already know about (unless you are careless in your wording). They still can't actually force you to say specific words. You can keep these secrets all the way to the grave if you really want to. Third, considering there is only 1 king and 1 stone, how long do you really think he will spend interrogating someone for any single case? Assumptions that the prosecutor is hyper-competent and has all the time in the world are just as unlikely as the king asking a single question and then letting the accused go because that single answer was really slick. Fourth, there is no such thing as a question that can only be answered by yes or no. Even if a question can be answered with one word, doesn't mean it has to be. Some of the comments about this sort of thing actually reminded me of a scene from one of Steven Brust's novels. I don't have the exact quotes but let me summarize: The assassin/sorcerer/witch Vlad Taltos is brought before the empress to answer questions about a murder. The empress questions him with the imperial orb (basically just like our truth stone). When asked if he killed the man, he does not answer yes or no. Instead he says something like: I believe he chose to die. When they ask if he is saying that the man committed suicide, he basically says that suicide is an accurate description. Vlad did in fact assassinate the man. However, the orb shows that all his statements are true. This is because he genuinely believes that anyone who voluntarily chooses to pick a fight with an assassin/sorcerer/witch is definitely committing suicide...and who wouldn't agree with that? :-) [Answer] The main thing everyone is overlooking is economy of scale. You've only got one truth stone, but justice needs to happen all over the country. If you are rich and noble you will probably be able to appeal to visit the Final Court (where the truth stone resides). If you are poor and common and guilty you may try to appeal in the hopes that it gives you more time. Regardless only the biggest and most important cases will go to the Final Court, most will still be handled by the local justice system, whatever that is. [Answer] There is another legal system where participants face a similar threat, where participants believe that false testimony has dire consequences even if no witness could otherwise prove they're lying. So we can look to that system for guidance on how this one might play out. I'm talking about *rabbinic courts*, specifically in the time of the Sanhedrin. The ultimate "stick" that the court had was to require somebody to *swear an oath*. What's the big deal about swearing an oath? To modern-day Americans, maybe not much -- just words and all that. But in its original context, a false oath was (and to many today still is) a transgression against God. Who, you know, would punish you for that. So you really, really don't want to swear a false oath, and it's safer to avoid swearing an oath *at all* because of a reluctance to bring out the "big guns", so to speak. The passages in the *talmud* that talk about how the Sanhedrin operated and what the laws of various cases are show a tendency to avoid oaths at all unless necessary. The truth stone, being not only a big gun but a singleton, will be similarly reserved for special cases. Most trials will be conducted as they were before. Second, when an oath was required, its text was fixed. I'm not sure if it's fixed by the law itself or by the judges, but either way, the accused (or witness) doesn't get to say "sure I'll swear, and what I swear is (carefully-crafted dodge)". When your truth stone is brought into a case, expect the one presiding over the case to similarly dictate what the speaker must testify to. Just having the "truth" isn't enough to settle some cases, though. Your truth stone, and an oath, measures *the speaker's perspective*. It doesn't measure actual truth. You could therefore end up with situations where two litigants *both* have the "truth" on their side, but their positions are incompatible. One of them is *mistaken*, but not *lying*. ("I picked up the lost bag of gold first!" "No, I did!" They both ended up holding onto it; who was *really* first? You don't know.) You will have cases where the truth stone didn't help you, in other words, and you should expect to fall back on what you would have done without it. (Sometimes rabbinic cases end with no oaths and "they divide the proceeds".) A final note: the rabbinic system I'm describing didn't rely *only* on the fear of false oaths, any more than the king here should rely *only* on the truth stone. Testimony of eye-witnesses and evidence are still big factors, same as with courts today. Using the truth stone is still the exception, as I argued earlier. [Answer] The perfect premeditated crime in this world would have a focus on obscurity: if you don't know who helped you rob a bank, then you can't incriminate them in court, truth stone or no. That type of cloak and dagger crime is infeasible in most cases, however. Most crime, then, would still need to depend on simply not being caught. Same as in our reality, Criminals would just have to make sure there are no witnesses, any witnesses won't turn to the law for help, or the law is in their pockets. While the initial reaction would be to use the truth stone in every case, it's likelier the justice system would evolve to only use the stone in the most extreme cases. There are many situations where the state would rather not let the infallible truth get out: when it wants to punish an individual regardless of their guilt, when the witness is a wealthy noble who has favor with the court, when a savvy criminal bribes the judge, etc. [Answer] The most pressing matter to any sovereign is staying alive and in power, and this stone would solidify his reign. Therefore, the king would use it to ensure the loyalty of those closest to him, such as his spouse, children, attendants, and advisers. Once the king realizes the great value of the stone(maybe after an assassination plot is foiled by it), he would take steps to secure it against theft. He would create a very secure site, guarded night and day by only the most loyal troops, whose loyalty is checked weekly by the very stone they guard. He would require all potential commanders of the army must be examined under the stone before taking commission, to ensure their loyalty, thus forestalling rebellion. The aristocracy would demand access to the stone for serious matters (including potential paternity of children.) They would have to petition the king, travel to the site of the stone and pay the king for the use. The priestly class would also demand access to the stone for serious matters (such as heresies and conspiracies.) While they would travel to the site, they would give favors instead of gold for use. Notable criminal cases which inflame the public's passions would also have the stone applied. Since the above situations would keep the stone pretty busy, common criminals would not have access unless they could get help from a member of the aristocracy. [Answer] Oh the mischief this would cause and so many ways the stone could be tricked! Some liars are so skilled that they actually trick themselves into believing their own lies. Pathological liars do it by nature. Imagine, if you will, a pathological liar making outlandish claims about witchcraft, or anything else. Someone drugged could believe that they have seen demons. The Salem witch trials were thought to be started by hallucinations brought on by illness or a fungus! Then again, there are faulty or false memories, especially during heated difficulties. How many people have already been sent to jail on false witness identification because the person looked like someone else or the witness remembered incorrectly. I once watched a social experiment (long before the internet) where they had someone walk into a classroom, steal a purse, then have a lineup. The instructor asked someone if the person had a beard (to plant the idea) and then the entire class falsely identified a man with a beard as the person who did it. Given this, it could cause a legal system to **devolve** into utter chaos until the stone is discarded. If you want to go this route, have the "gift" be given by someone who knows it will have this effect. It could either be an active enemy of the king, or a trickster archetype. [Answer] **How much justice does the king really want?** Commoners might come out a little up (until the civil war comes through) but kings justice was often counted as pretty good. Most crime is pretty simple, and leaders who aren't good judging people are in a lot of trouble anyway. Depending on a stone may support the mystical awe of kingdom, but might sap some of the personal majesty. And then there's the problem of the stone giving the politically wrong answer. Dubious allies are quite possibly the only allies a small king has, putting them to the question could be very embarrassing. Even the threat of such a thing would cause elites to become unstable. Plotting is traditionally the sport of choice for many nobilities. The whole truth and nothing but the truth would ruin the court; I'd predict a rash of wealthy people suddenly being too sick to meet the king. Possibly sending younger sons or whatever innocents could be procured at short notice in their place, but quite possibly taking a stand of rebellion rather than submit to what they know will doom them. [Answer] Brainwashing is not particularly difficult with the right setup, and memory is famously fallible. Organised crime would quickly learn to implant suggestions in their own operatives that they did not do the things they did, and soon after that they'd learn the value, in a world with an external arbiter of truth that is believed to be infallible, of 'convincing' bystanders that they saw something that never happened. [Answer] Its very unlikely to have a significant effect on the world, assuming a stereotypical medieval ruler. First, in regards to criminal justice, it is likely to restrict the options of those with power - the ruler is going to be able to do what he wants under a medieval system, which is more difficult to do if a stone keeps telling people he's wrong. It's more likely to be kept for use in the ruler's interest (which is unlikely to involve justice beyond that necessary for keeping the kingdom functioning). Further, on those instances when it is used, it's unlikely to be foolproof: The way to tell a lie to a stone that detects intentional falsehoods is... to believe it's not a lie. This is something (I've read) politicians do to be able to speak falsehoods convincingly - using mental gymnastics to consciously change their beliefs. You can do it with application of various cognitive bias, repetition and wordplay. For example, If a noble is plotting to overthrow a King and asked a question: "Are you plotting to overthrow the King?" They can choose to take the question via e.g. separation of individual from office - they can think: 'I'm not plotting to overthrow the King, I love the Monarchy, I'm doing it to 'save' the monarchy from the current monarch and install a better one (me) that safeguards it' Or lets say that the accusation was a noble mass murdered a bunch of peasants in front of many witnesses: They could say "I have never killed a single person" and mean * I have not killed only one person * I stabbed them, but blood loss is what killed them * I merely ended their miserable existence, they had no lives * They were not real people, just peasants. They don't count. * The 'me' back then isn't the 'me' now, I've changed, therefore "It wasn't me"(Like shaggy indicated, this works on any accusation) All you have to do is believe it for as long as it takes to speak a sentence and get away with murder. How many instances like that before the stone is thrown out as useless junk? [Answer] Expanding on most of the up-voted answers, I'd say the main change on the justice system would be that philosophy and logic get a massive development boost and a strong influence on the justice system. There would be a short arms race about tricking the stone vs. asking questions in a good way that doesn't allow trickery. [Answer] Never mind the Middle Ages - it would drastically change the legal system even today! Basically what you've described is a "High Court" or "Supreme Court" whose judgement is not just the best available but actually ***correct***. If everyone has a right to a fair trial (and even today and even in the West this can be a questionable concept), the judicial system has to have the possibility to escalate up to Judgement By Stone. Beyond that, no appeal is possible. If sentencing is delayed until after appeals up to JBS, every criminal will try to push for that. Since there's only one Stone, this will inevitably lead to a backlog, so clearly this isn't in the public interest. You would want some kind of penalty if you initiate a JBS appeal and are found guilty (or if you back out before the appeal happens because you know it'll find you guilty). Something like parole being unavailable for a failed JBS appeal might do the trick. Since the Stone is now critical to your judicial process though, it needs to be kept in the local equivalent of Cheyenne Mountain, so that nothing short of a massive invading army can tamper with it. [Answer] Sadly, as often happens in real life, people will deny that the stone actually works, no matter how much evidence is presented as to its inerrant nature. Furthermore, if the King attempts to enforce the stone's results, the narrative will then shift to portray them as favoring the King, and thus paint them as corrupt. It would probably take many generations and a solid record of veracity for society to start slowly accepting the results as "true", and even then, a single influential person claiming the results are wrong could sway the opinion of significant portions of the populace. For real life examples of this process, look no further than 9/11 truthers, the moon landing "hoax", the anti-vaccines movement or global warming denial. [Answer] The answer can be derived from one of your comments: > > @CortAmmon For the case of this stone, it's 100% on the speaker's shoulders. If the speaker is talking to a stuffed bear (believing, incorrectly, that the bear can hear him) and is trying to deceive the stuffed bear, the stone will turn red. The listener (deceived, not deceived, not listening, or nonexistent) doesn't actually matter as far as the stone's reaction > > > This says that, so long as the speaker does not believe they are deceiving, they can say just about anything. A natural result of this would be the omnipresence of religion. Religious leaders are constantly trying to enlighten others to the truths of their religions, and we may assume they 100% believe their claims. Accordingly, they could make any statement they please, so long as they feel they are leading the listener towards the greater truth. Any lie would be accepted so long as the lie's apparent purpose is to lead people towards the truth as the speaker perceives it. Thus, every individual in the world who might be subjected to the stone will soon find a "higher calling" which permits them to say anything without believing that they are speaking deceitfully. Machiavelli will say "The ends justify the means" and the stone will glow bright bright blue. [Answer] ## How many of all crimes are actually NOT solved because of a lie? If you think of a medieval society, most crimes will actually not be solved, because you have no perpetrator. If something was stolen or there was a break-in, the problem was usually not that you had a suspect who is lying. Most of the time you will have no likely suspect. And if you have a likely suspect, the burden of proof was not with the court in most cases - if you catch a lowlife with stolen goods, he will meet his fate. **So the truth stone will most likely change nothing for 95% of common crimes and law enforcement, because investigation to find the suspect is harder than convictim him.** So the only cases where the stone would actually change the system are when you have a likely suspect (or a small set of suspects) and have to find proof. These will mostly be cases involving nobles or rich citizens. - And many cases there will revolve around corruption, conspiracies and a lot of money or power. ## Everyone with power as something to hide Since you will probably find a "guilty" question for everyone if you just know enough about them, the main question will not be how the stone works, but who will be tried and asked what question. So there will be a lot of blackmailing, because almost everybody can likely be sentenced by the truth stone, if you just ask the right questions. In the end the stone will most likely be used to get to know important truths outside of court, or for big publicity stunts. So the king will train with the stone, what he can say in front of the crowd and will give some important public announcements with the stone in hand for effect. Just as the king will regularly check his advisors, ambassadors, most nobles and other important figures for loyalty. Maybe anyone with power or money has to come to the king once a month and declare their loyalty and love. And a red glow will have to be amended with a high fee, and a promise to work on ones love for the king. [Answer] Trails would be shorter if there wouldn't be as much need for Witnesses when accused himself can be his own witness. Less people would be falsely accused since now you can't torture someone into a confession. ( unless he really is guilty). That's not to say that torture wouldn't be used this is still the Middle Ages after all but only for those who were found to be lying. Overall I think would make any medieval Kingdom a slightly better place to live. Wouldn't solve all the problems of the time but it would improve justice system somewhat. [Answer] There's a book that explores this: <https://en.wikipedia.org/wiki/The_Truth_Machine> However, you have only one which opens up the possibility to it disappearing/being destroyed. I would consider one of these outcomes to be almost inevitable--too many people in power are guilty of dirty deeds they won't want exposed. ]
[Question] [ It's common for people to say that if a time traveler or an alien displayed advanced technology to ancient or medieval people, that they'd assume it was magic, and either worship him as a god or burn him as a witch. But if aliens visited the Earth tomorrow and had technology hundreds of years in advance of anything humans have yet invented, I'd think few if any would suppose it was magic. You might say, "Yes, but we are technologically sophisticated people, unlike those medieval people." But people in the Middle Ages built complex clocks and other mechanical devices, and cathedrals and other buildings at least as grand as anything we build today. Ancient people built the Coliseum and the pyramids. The Greeks built complex mechanical devices -- like the [Antikythera machine](https://en.wikipedia.org/wiki/Antikythera_mechanism). Would the ancient Greeks have assumed that, say, a flying machine must be magical? Or would they have said, "Ah, like Daedalus built"? So my question is, Is there any evidence that ancient or medieval people would be unable to distinguish advanced technology from magic? For example, are there documented historical examples of, say, 19th century Europeans encountering a primitive tribe and the primitive people thinking the European's machines were supernatural? *Later Thought* My intent here was not to get into a discussion of whether there really are supernatural forces in the universe. Whether there really is a God who performs miracles, or ghosts, or people with psychic powers, doesn't affect what I was driving at with this question. You may think that people are foolish and gullible to believe in religion, but even if you're right, it's not a matter of confusing technology for the supernatural, it's a debate about whether the supernatural exists. I admit I may be splitting hairs here, but I think it's a fundamentally different idea. Suppose a con man tries to convince people that he can read minds. The issue isn't that people are confusing technology with magic, but that they are being duped by a con man. Odds are he isn't using any particularly advanced technology, but simple stage magic tricks. Very little stage magic depends on high tech gadgets: it's almost all slight of hand, a box with a hidden compartment, smoke and mirrors. I know some mind-reading tricks, and none of them involve high technology, they're all about having an accomplice who uses code words to pass you information and that sort of thing. *Very Late Update* I see a number of posters here have made comments on the order of, "If you don't understand it, it's the same as magic." No, it's not. It's true that people use the word "magic" colloquially to mean "stuff I don't understand" or even "stuff that's really impressive", as in, "we talked via the magic of cell phones" or "wow, this new cleaning product works like magic!" But my intent with this question was that I meant "magic" in the literal sense: something supernatural, ghosts, psychic phenomena, etc. I'm sure 90+% of the population of America and Europe don't know how cell phones or computers work. But they don't suppose they are literally evil spirits captured in a box. *Very Late Addition 3 Years After Original Post* I don't mean to sound rude when I say this, but when I've asked this question, here and elsewhere, someone always brings up Arthur Clarke's quote, "Any sufficiently advanced technology is indistinguishable from magic", and/or mentions some science fiction story they read or saw on TV where primitive people think the space travelers are gods (either advanced aliens visiting primitive Earth or advanced Earth people visiting some other planet). I'm sorry, but that doesn't answer my question. I'm not asking if any 20th or 21st century person THOUGHT that primitive people might confuse technology with magic. I'm asking if there is any evidence that primitive people actually did. [Answer] As far as I can determine, the closest we have to hard data on this (which is not that close) would be first contact with people who have been isolated for a long time and have not developed or used technology themselves. This page lists six relatively recent incidents: [6 Isolated Groups Who Had No Idea That Civilization Existed](http://www.cracked.com/article_19976_6-isolated-groups-who-had-no-idea-that-civilization-existed.html) (cracked.com, 17 aug 2012) Based on that article, (not from a great source, but hey), I searched and read several other sources, like: * [Incredible homes of the treehouse tribe : Amazing images show rickety structures built 140ft up by secretive Korowai (who were unaware of anyone else on earth until 1970)](http://www.dailymail.co.uk/travel/travel_news/article-2958291/The-tree-dwellers-New-Guinea-Amazing-images-offer-glimpse-secretive-Korowai-tribe-living-rickety-treehouses-140ft-remote-rainforest.html) (Daily Mail, 18 Feb 2015) * [The day the Pintupi Nine entered the modern world](http://www.bbc.com/news/magazine-30500591) (BBC News, 23 Dec 2014) Among others. I searched and read a lot, looking for anything along the lines of "the long-isolated tribesmen were amazed at seeing a cell phone for the first time, and asked 'what kind of magic is this?'" But I have **not** found anything that relates a story of confusing technology with magic. Just to be clear, I can't say that has never happened, just that a fairly lengthy (and work productivity destroying) search of the internet has not turned up any documentation on that. What **is** documented multiple times is the mistaken impression of the more "advanced" *people* being mistaken for supernatural beings - either gods or devils. What is fascinating about this is it could lead one to a more supported and also surprising maxim: "Any mildly different human morphology is often mistaken for inhumanity". Meaning, just having white skin, thinner noses, and different hair can make one seem to be **not even human** (at first) to someone who has only ever seen other humans with dark skin, broad noses, and curly dark hair. Rather chilling when you think about it. Attempting to extrapolate what the long-isolated peoples in these first contact situations might think of about *technology*, they would likely see it as works of supernatural beings, and maybe not magic so much as miracle (or devilry). I suppose that's a form of magic, but it's interesting that the culture shock experienced by these peoples does not seem to be secular. Now if we imagine that a group of humans were somehow whisked away from earth 10,000 years ago, have developed on another planet, and now return to earth with no head hair and greenish skin, one good guess at how our current culture would react would be to mistake them as completely alien, and not human at all. From there, most people would probably spare little thought to whether these "aliens" were wielding magic, technology, or anything else, and would instead be more concerned about whether they mean us harm, or will steal our jobs, or threaten our religious beliefs, etc. [Answer] The example I tend to use for this question is as follows. **In your pocket is a small flat box.** It can be used to talk to other similar boxes. It can display almost any information on request. You can ask it, for example, who the most beautiful person in the world is. **There's a reasonable chance this box is sealed.** You've been told approximately what's inside but it's too valuable as an intact unit to actually look. **Would it make any difference if the box contained a trained demon?** The traditional statement is that [Any sufficiently advanced technology is indistinguishable from magic](https://en.wikipedia.org/wiki/Clarke's_three_laws), can you actually, on the surface, tell the difference? One could also say, "*sufficiently advanced magic is indistinguishable from technology*", or possibly [Any sufficiently analyzed magic is indistinguishable from science!](http://www.girlgeniusonline.com/comic.php?date=20081205#.VoJ-K7_eJSA) The only reason you say it's not magic is that we've been taught to believe that magic doesn't exist. First you have to define magic, the simple definition is "something we don't understand". We now seek a scientific or technological answer to the question, but your mobile phone, in its sealed case, is indistinguishable from magic. [Answer] It depends: When looking at general cultural development, and the structure of existing religions, we can make out a single connecting thread that could be helpful in answering the question: The harder something is to explain, the more likely it is that someone will accept a incomplete or wrong explanation. Also a thing to keep in mind: You don't have to convince the smartest minds of each generation, just the majority. --- Even popular fiction has, by now, accepted that a electrical torch probably wouldn't impress any but the most simple of civilizations, but there are other things which are far more likely to impress older civilizations, especially if you are willing to put on a good show. Wireless communication: Invisible, instantaneous, and almost no way for a primitive civilisation to understand it. This one probably will net you at least the title wizard, or a quick burning at the stake. Big Loud Machines: The bigger and louder the better. You'd probably have to cheat a bit, only showing off the machine at night, or during dense fog, in order to maximize the shock value of facing for example a loudly roaring attack helicopter. Advanced Chemistry: Even nowadays you can form a moderately sized cult provided you have enough drugs. If you have access to something airborne, all the better, you can form the next temple of Sybils. To summarize: Sufficient tech actually puts you on a power level far above what is possible during the times, and power is always a good nurturing ground for faith. --- But these are all just theoretical scenarios. What lends credibility to the idea are three things: - Cargo Cults - Folklore - Religion **Cargo Cults** are a very real life example of a "mundane" thing, taking the guise of something ritualistic and supernatural. But it also shows, just how disruptive the influence of your knowledge/technology has to be to actually create such an effect. **Folklore** is a nice little account, of just what people are willing to believe in/ what people don't bother to question cause it works. **Religion**... Hoh boy... I kind of like one of the ideas Terry Pratchett throws around from time to time: For most people faith was probably not a thing of burning passion, but a sort of background noise, daily rituals and small gestures ingrained in your culture, but not necessarily backed up by true belief. This also makes it that much harder to dispel such beliefs. Any new contender on the block, trying to pose as a god, probably would have to go up against decades of social inertia if he doesn't manage to integrate himself in this culture. If he does however... well, let's just say, that there are still people who believe that all of humanity descended from two people, even today. [Answer] Aladdin has a Genie. He can talk to that genie, and ask for things. That's magic. Captain Kirk has a computer-controlled replicator. He can talk to it and ask for things. That's technology. So what's the difference? Well, the difference is that we are made believe that the replicator/computer is built by and completely understood by humans, and follows the known laws of the universe. While the Genie just exists, and his magic abilities are not understood by humans. Now you might say, the Genie has a personality, the Star Trek computer controlling the replicator doesn't. But then, Data does have a personality, as has the Emergency Medical Hologram. And yet, both are considered technology, not magic. So the difference between technology and magic is whether *you think* it needs some supernatural powers to work. Thus whether relatively primitive people would "confuse" technology with magic would very much depend on how they learn about it, and their general mindset about such things. As of how much the mindset matters can be seen with people who claim to have supernatural abilities today. Believers tend to believe those people have the abilities even after they have been shown that such abilities can be faked (noting that the fact that you *can* fake them doesn't proof that *their Guru* faked it). While non-believers will be sure it is a fake even if they have no clue how those people did it. [Answer] I don't have anything to add about relatively primitive people, but many relatively advanced people confuse magic with technology. We grow up in a society that teaches us there is no such thing as magic and which treats people who insist in believing in magic as fools or charlatans or con-men. So we get the phenomenon that people insist magic is science without having even half a clue about what science really is. ( They gave up studying science at the first opportunity. It was too hard or plain incomprehensible. ) Hence homeopathy. Orgone therapy. Secrets of Area 51. Heavily advertized cosmetics with added magic, sorry, vitamin QX71-complex. And less harmlessly, cults of various sorts whose members are foot soldiers for leaders with a secret agenda: get rich at the suckers' expense, or worse. Sometimes much worse. Medics know that magic can actually work. They call it the placebo effect or the white coat effect or the talking cure. There is some scientific understanding of why it works but the patients are not party to that understanding and it would stop working if they became convinced of that science. Hold up a mirror to our own society and in it you'll see the primitive one. We're all running our intellects on an ape operating system layered on a reptile's base hardware. [Answer] It would depend on their cultural understanding of magic. Our typical Tolkien/D&D derived medieval fantasy worlds tend to have models of magic that are very amenable to the identification of advanced technology as magical. Crystal balls, particularly variants such as the evil Queen's mirror on the wall and Tolkien's Palantir, are basically cellular phones, with all the attendant powers and vulnerabilities of that device. The idea of cutting someone open and performing surgery on them to someone working with a humoral theory of human physiology will likely seem magical, as you are (to their understanding) correcting the flow of vital essences around the body. To the anachronistically Cartesian-dualist medieval fantasy mind, surgery is sorcery. But there are other concepts of magic less conducive to identifying technology as magical in nature. For instance, if you have a basically animistic belief system, your cell phone doesn't resemble magical spirits as they conceive of them, it's more like a type of creature, even more-so considering an automobile or jet. Now, if you revealed to them that these creatures are not just tamed by these strange foreigners, but actually created by them, you're probably going to disrupt their core metaphysical beliefs and wind up identified as some sort of creator god. But probably not a "magic" spirit, you come at those another way. Chaos Magick is a pretty recent development in occult thought, but the concept of magick (family of concepts really, as chaos magick is utterly pragmatic and practitioners change their favored concept as often as their underwear in order to better game themselves in different circumstances) it promotes usually involves something like modifying probabilities, fetching information from other universes/our future mind/a god, demon, or saint who likes to do fetch quests, or even just influencing which of the possible futures you or we actually wind up in ("Sorry, alternate selves, you should have invoked better!") This kind of concept of magick seems less likely to identify technology as magical in nature, but at the same time is very likely (i.e. in fact does) assimilate technology into magickal practice. For instance, there are certainly several apps in smartphone marketplaces that will simulate a tarot deck or rune casting. And chaos mages are probably the only ones using them, since they're the mental contortionists who can actually spin a criticism of pseudorandom number generators into an argument for why e-divination is even better than the 3D variety. [Answer] I find these concepts easier to understand if we stop thinking about them as categories and start thinking of them as a continuum. Why can't the ancient Greeks consider an airplane to be a magical device similar in nature to Dadelus's flying machine? Why limit ones self to merely one way of thinking or the other. Of course, I readily admit the terminology is well entrenched for treating them as categories, so the next best thing would be to have categories that blur together nicely. A while back I came up with a chart I find very effective at capturing what I perceive as the relationship between magic and technology. The chart is a quad chart with two axes. The vertical axis is "How predictable is this thing when operating within well understood bounds." If you have a well maintained gun, at standard operating conditions, and you pull the trigger, how well can you predict the result? If you have a computer, with 1.7 billion carefully arranged silicon transistors, how well can you predict what will happen when you hit the enter key, or the send button? A highly predictable thing is rarely "good" in its own right, but it is often a valuable tool to allow you to do good using it. The horizontal axis is "how well does the thing do 'good' when operating outside understood bounds?" How well does it fare when grappling with the unknown unknowns? Would you be comfortable leaving it up to its own devices, or do you have to first make sure you understand its operating environment to make sure it doesn't do anything wrong (AI in a box theories: I'm looking at you)? ``` How predictable is it when operating in well understood regions? | +---------------+---------------+ | | | | Predictable | Technology | Intriguing | | | | | | +---------------+---------------+ | | | | Unpredictable | Boring | Magic | | | | | +---------------+---------------+ -----poor--------------good--- How good when acting outside of clear understandable regions of operation? ``` Some explanation of the regions: * **Boring things are simply not all that useful to think about.** You can't really predict what they're going to do, and they don't seem to do anything good on their own in any unpredictable fashion. Rocks sitting by the side of the road are pretty boring, unless you throw them (in which case they will follow a predictable trajectory). * **Technological things are only useful if you think through them.** Technological contraptions rarely do "good" unless someone thinks about how to use them for good and applies them that way. On their own, they tend to be rather ambivalent. A computer tends to not do much good without someone telling it what good to do. However, technological things respond very well to someone predicting how they will behave (mostly because they are designed to be predictable). You may not have predicted how your iPhone would check your mail for you, but Steve Jobs did! * **Magical things do good when you least expect them to.** You cannot really explain a rhyme or reason to it, but for some reason these things tend to do what you would consider to be good, even if you give them nonsensical instructions. Consider, as an example, the reading of runes drawn from a container. In theory, the runes drawn are highly unpredictable. However, for those who believe in rune reading, they find a remarkably amount of good comes from these runes, even when they aren't 100% sure why. * **Intriguing things are... intriguing.** They can do exactly what you ask when you ask under the right circumstances, but when you ask the wrong thing or at the wrong time, instead of being predictable, they simply do good things. The clearest example of this is human beings, especially your own children. They can follow orders perfectly in many situations, and then do something completely brilliant, unexpected, and contrary, and leave you wondering who is raising whom. There are non-animate things that can do this too. Safety equipment often works its way into this category. While a great deal of safety equipment is designing it to work flawlessly in the well defined regions it is supposed to be used in, the most loved safety equipment also has a strange and curious tendency to do what needs to be done in situations *well* outside of that standardized zone. This shows a few things. First is the key for your question: which category something is in depends on their point of view. How well can *they* predict what it will do? What is *their* definition of good? iPhones seem magical to many people because the phones were very predictable technology to the developers, but few end users truly understand what goes into making them do what they do. They just observe that the phone, with its apps, does good for them surprisingly often. This actually expounds upon Arthur C. Clarke's famous phrase, "Any sufficiently advanced technology is indistinguishable from magic." But it also shows that there's a second half to that: only "good" advanced technology earns this axiom's fame. Dinosaurs wouldn't find cell phones magic. They'd find them boring -- they don't exactly do anything to better a dinosaur's life! It also suggests that opinions can change over time. You can have a magical device that, upon learning how it works, becomes technology. Or it could become boring, when you discover it can't actually do good on its own. Or it could even become intriguing if the understanding makes you appreciate it even more. Likewise, technological devices can become intriguing if you realize how effective they are in situations you didn't expect. They can even turn to magic if you realize just how hopelessly little you understood them and how they do good! These categories are also fluid. There's no sharp line between technological and intriguing things. They flow. Going back to your original question, the way the primitive cultures approach a technology such as an airplane depends very much on them. They might treat it as magical, or they might treat it as magical with an intent to develop an understanding of it. Accordingly, they may attribute personalities, or relate it to existing technology such as Dadelus's flying contraptions. Or perhaps it is forbidden for humans to fly above the jungle canopy, and the airplane is heresy! (I intentionally did not include a third column for things that do "bad," but you could add it if needed!) As a closing, consider stage magic. Being magic, it does "good" when you don't understand how to predict how its done. Some tricks, when you learn their trick, become technology, especially prop intensive tricks. Others, such as cons, become boring when you learn how they work. However, the most beautiful stage magic illusions out there are the ones where, when you know the trick, they become intriguing. You understand what is happening, but the execution is so flawless and beautiful that you *want* to believe and want to help others to believe. That's magic. [Answer] One big different between people today and people in the past, is that most people in the past strongly believed in magic, while today very few do. People look for what they are trained to look for. If you are told by all your authority figures that magic exists, and that there are demons and witches and curses and such, then anything you don't understand that looks like magic must be magic. Likewise, if you are told by your authority figures that everything is technology, then anything you don't understand must be some unknown advanced tech. If aliens visited with replicator technology, most people now would look at it and wonder what science makes it work. In the past people would wonder what magic powered it. If a real wizard appeared and was using a wand to perform real magic, then most people today would look at it and wonder how it worked, and if they could take it apart to see the machinery inside. Edit: Turning the old quote around, any magic is indistinguishable from highly advanced technology. [Answer] Yesterday I gave a ride to two friends who are practicing ultra-orthodox Jews, and had never received any technological or scientific education whatsoever. I turned on the Waze app and was playing with the text to speech. One of them said that he heard that the makers of this app invited some people to a studio where they recorded the names of streets, the numbers, and a few other elements, and then it is "simply played back" in whatever order needed. I mentioned that one of the voices was completely computer generated, with no human voice ever recorded behind it. That's impossible! The other man said. I think it's done like the numbers that turn into letters on the screen said the other. I was once in a course and they told us that there are millions of little numbers going through the computer and quickly turning into letters on the screen. Oh! said the second man. I heard about that. It's talking in computer language. It's one of the creator's miracles. [Answer] I think the main difference between magic and technology is one of semantics. In most of the fantasy lore that I'm aware of, the wizards/mages/arcanists/ect usually spend long years studying these cosmic forces, and practicing the ways in which they can be manipulated. Sounds like college. The main difference between a mage and an engineer seems, colloquially anyway, to be that the focus of the mages studies are imaginary. Imagine, for example, a world where electricity doesn't exist. Then someone in that world writes a story about the wizard Samuel Morse and the 'magical' telegraph system, which he built using arcane knowledge of 'electrical forces'. In the story, he's a wizard, because he's using imaginary forces, but in our world, he's just a smart guy who made some technology. I suppose this is fairly specific to a more Fantasy type magic system, and the OP was more talking about 'primitive' people who really believe in some sort of theology, rather than some novel or game that we know is make believe. I guess it depends really on their definition of magic. Do they believe that spirit forces exist which actually do not exist? Do they misattribute the functioning of my technology to the wrong forces? That is sort of the essence, I think, of the original Cargo Cults. They got the causality wrong, they thought building runways would cause planes to land. They thought the planes were sent by gods. They just got the hypothesis wrong because they never went to the Mages College. It's not that planes aren't 'magical', planes are magical! It's like Louis CK says, 'you're sitting in a chair in the sky! You're like a Greek god right now!'. What I'm saying, I guess, is that technology is just 'real' magic. So the question isn't, would primitive people mistake technology for magic, it's more, could you lie to primitive people about how your technology works? To which I say, certainly - if you went back in time and specifically told medieval people that the robot you brought with you was a golem you crafted through arcane sorcery, I'm sure they would believe you. But if you tried to explain the truth to them, they might not get it (most people don't understand electronics) but they would assign the correct causality to it, so it would be technology not magic. [Answer] If modern people that grow up with technology can confuse technology with magic then primitive people that don't grow up with our level of technology could easily confuse it for something else. For example, in the 1990's there were not as many laser pointers so I had no experience with them. One night I was walking outside and this little glowing red thing appeared on the ground and started following me around. It was very fast and would sometimes run away at an amazing speed and climb a wall and then run back in the blink of an eye. It was glowing but there was no light beam going to it the way that a flashlight would shine. I was wide eyed and scared. I don't think I thought "magic" but I surely thought something strange was going on. I looked around and couldn't see anything else. It was sometime later that I started seeing people with laser pointers and realized that someone had been pulling a prank on me that night. I didn't immediately think "magic" but AndyD273 makes a good point that it depends on what you've been trained to look for. [Answer] Yes, this is well documented in history. I have been reading a lot of books about early European explorers in Africa recently, and the tribes there believed much of the explorers' technology, and especially the gun, was magic. Here's some representative quotes. > > Most impressive of all, however, was the power of the gun, which was presented to the African populations as the white man's magic and witchcraft - and a very strong witchcraft at that. - The Challenge for Africa, Wangari Maathai > > > and > > The Masai, living near by, know nothing of guns, nor seem to have any desire in that direction. To them the gun with its noise and smoke is a mysterious product of the white man's power of magic. That there was some uncanny connection between those little punctures in the skins of the stricken animals and the hollow tubes of our rifles, they understood, but beyond that they shook their heads and answered "dower" (magic medicine). - Scouting for Stanley in East Africa, Thomas Stevens > > > The real difference is whether a society is already conceptually familiar with a scientific/technological mindset or not. Once one is, even if it is primitive, it will interpret advanced items with the mindset of "they must be advanced technology". If one is not and interprets everything as magic or spirits, then it will of course interpret them in that way. (I will note that in a story, either one can be wrong...) So a more "primitive" but fundamentally technology-minded society would probably not consider higher tech to be magic. [Answer] If you present it well, of course! It's less about the level of the technology, and more about the way in which it is presented. After all, stage magic is indirection mixed with showmanship and a dash of technology. Consider a magic show I remember seeing when I was younger, around the late '80s, maybe early '90s. It was part of a yearly show they did back in the day where the greatest stage magicians would try to one-up each other. The actual show was in a theatre, but they broadcast it as well. I vividly remember one act involved impaling one of the magicians through the stomach with a giant conical drill bit, and hoisting them until the magician was fully horizontal - well above the heads of the helpers. After a few moments, the magician was lowered, the drill was removed, and bows were taken. The magician was, as expected, fully unharmed. It looked very, very real. Would it fool a more "primitive" society? Definitely. You won't fool everyone, particularly the local magicians (nearly every human culture has them), but you'll fool enough people to make it worth your while. If you are really good, and you have good tech, you might even plant a seed of doubt in the minds of the local magicians - the imposter syndrome is your friend here. If you're really unlucky, you landed in a world where magic is real and the local equivalent of Merlin will torch you for being cheeky. [Answer] I see that a perfectly straightforward interrogatory: "Would any primitive people really confuse technology with magic?" has led to some truly unusual postings. Here's the short-form reply--- this "scam" was played on several Native American tribes by a scam-artist whose name was evidently James Williams, beginning around 1854 or 1855. Williams was in Boston when he had been introduced by a confidence man to "Electropathy." That was the notion that electricity could be used to cure diseases. The source of the juice as a Voltaic pile (a collection of early batteries) that had been made in France, where the whole "Science of Electropathy" had begun. Back then, electricity was used both for medical quackery, and somewhat less-commonly, for winning bar-bets. . . the "Doctor of Electro-Pathic Energies" would work "cures" on "upper-crust marks" in communities. (Meaning the people in town with lots of money, and ample time to worry about their health.) Most were like the other "Snake-Oil Salesmen," making their fortunes by rapidly shifting operations from town to town. Electric shocks didn't do diddly, in all reality, but the placebo effect was good enough for the "marks" to feel better for a short period of time---or, for them to claim they'd felt better; nobody likes to admit being taken to the cleaners! If the con-man wanted a couple drinks and some quick money, he'd go to a tavern, and boast he could knock down the strongest man in the room with just a touch. He'd then zap some ham-handed and ox-like drunk with a massive charge of electricity, using the insulated copper rod "wand" wired to the Voltaic batteries. Usually, although not always, the charge would pole-axe the drunk long enough for the shyster to grab his winnings and whip his horse to a lather, getting out of Dodge (or where-ever.) However, this wasn't a lead-pipe cinch, and the supposed "victim" would sometimes stagger erect, blood in his eye and murder in his heart. One version of the tale alleged Williams got the Voltaic outfit from the "effects" of a "late" con-man . . . . Somehow or other, Williams had managed to get his hands on a "Voltaic Pile," which he fitted into a back-pack or pack-basket. It was said that he had covered the pack and most of his back with a voluminous buffalo-skin cape, making him resemble a hump-backed bison bull. He then "toured the Native American tribes of the far West." According to my late uncle, who was a Lakota shaman, (and who had first told me about Williams in the early 1960s) Williams had boasted he was the "Son of the Sun," come to Earth. He acted more like an Aztec god-king, though, as he settled on the idea that "his people" should honor him with those gold and silver coins used by the Whites! Obviously, he ran into opposition at every village; from both warriors and medicine men. He had thought it all out, however: In the "showdowns," he would allow his opponent plenty of time to "raise his Powers." Then, step up and casually knock his opponent flat with a vivid blue spark! As these confrontations would usually take place at night, the blue spark jumping several inches from wand to victim, would be obvious to most onlookers! He had apparently wanted his victims to work up a sweat, because the shock would be more potent, that way! During his time among the tribes, he had also made sure to marry all the available eldest daughters of the chiefs along the way, so even after the batteries had given up the ghost, he could rely on many area blood-alliances in the form of children! Eventually, it was said, Williams tried to "return to Civilization" with his "Tribute;" but disappeared along the way. So to answer the question, YES! This rascal had managed to use "high-technology" in the form of a Voltaic array to convince several hundred Native Americans in several Tribes that he was a "Supernatural Being! [Answer] Consider a person who develops a small implanted personal teleporter, triggered by a recognized mental exercise. They then go on tour showing off their magical ability, like Penn and Teller, David Copperfield, Harry Houdini. Now consider all of us today, looking at our pc, mac, smartphone, tablet, etc with no working knowledge of the physics of teleportation, mental triggers, and cybernetic implants. Would we be sitting in the audience going "Nice teleporter!" Or would we be going "Wow, nice magic. (I bet they do it with smoke and mirrors)" We're considering ourselves to be quite sophisticated when it comes to technology and we'd like to think that we wouldn't be surprised or fooled by advanced technology. But truly advanced tech would be so out of our experience that it could easily be mistaken for magic. [Answer] Uh, in what respect is bringing technology from a different world that cannot be reproduced by means available to *local* humans (as well as the individuals bringing the stuff in) in any amount of effort and time different from "magic"? Something like a computer may obey understandable principles, but that's usually also ascribed to magic. Could you create a computer from its raw materials, ores and sand and stuff like that? In what respect would it be non-magical in a world without the supportive technology? [Answer] What is your definition of magic? Not all languages have a word that exactly corresponds to English "magic". What if their language has "wizardry", "high knowledge", "prohibited knowledge", "sacred art", "unclean art" or something. What of these is magic? Well. I suggest the following. So, First possibility, the most direct thing that can be defined as magical is something done by the force of thoughts, words, spells as opposed to done with hands. Second possibility is the divine (or spiritual) intervention (by the god, spirits, ancestors, higher beings). Third thing, is something related to life, consciousness and biology because living beings cannot be made by hands even now and there are philosophical issues with mind. Fourth is anything done with hidden, secret knowledge (maybe obtained from gods or powerful ancients), even if by hands. --- So given that, we say that various people can or cannot perceive a thing magical depending on their version of the origin of the thing and their definitions. [Answer] Theodore Dalrymple writes in an article about [Africa](http://www.city-journal.org/html/13_2_oh_to_be.html): > > The examination over, we chatted about the Congo: he was delighted to meet someone who knew his country, by no means easily found in England. I asked him about Mobutu, whom he had known personally. > > > “He was very powerful,” he said. “He collected the best witch doctors from every part of Zaire. Of course, he could make himself invisible; that was how he knew everything about us. And he could turn himself into a leopard when he wanted.” > > > This was said with perfect seriousness. For him the magical powers of Mobutu were more impressive and important than the photographic power of satellites. Magic trumped science. In this he was not at all abnormal, it being as difficult or impossible for a sub-Saharan African to deny the power of magic as for an inhabitant of the Arabian peninsula to deny the power of Allah. > > > There are many reports of tribes considering photography to be dangerous because it supposedly steals a persons soul. You can make a decent argument that those tribes consider photography to be magical. Even among people born in the West you find many people who consider Derren Brown to have real magic powers and aren't willing to believe that he's just using a bunch of tricks. [Answer] There's an important qualifier in the adage that you're missing: "*Sufficiently* advanced technology is indistinguishable from magic". The basic idea is that there are things we know we can do, things we know we can't do but that we can conceive of, and then things we don't even know we can't do; it's inconceivable to think of the ability at all because we have no parallel to the ability in any human experience. As modern humans in the age of technology, we think that window is shrinking; humans at this point have seen enough "can'ts" go by the wayside that the ability to accept that new things are possible because of technological progress, even if the exact workings of the technology are totally unknown, is fairly widespread. Modern humans in fact go a bit far the other way in assuming that something is technology and *not* magic; when the Afghan Taliban first saw U.S. Special Forces in the field, they thought they were up against robots or cyborgs. They had these concepts of self-aware machines and human/machine hybrids, and when they saw what was actually a human in full ballistic armor, comms and nightvision/augmented reality headsets, they went to the extreme of their concept of technology. However, there's probably a litany of things that are so far beyond any human experience that we've never even thought about doing them. By definition, this set of abilities is beyond our comprehension and is probably shrinking; if we can imagine uploading our consciousness into spacetime itself and becoming beings of pure energy able to transit spacetime as if all known dimensions were spatial, then it's hard to just come up with something we've never thought of doing on the spot. To experience something totally beyond our comprehension would likely cause us to either oversimplify it; we likely wouldn't use "magic" to describe it, but we'd likely explain it to ourselves the way parents explain TV to their young children, because they'd be unable to comprehend the required technical detail (and many adults don't realize just how complex television as a technology is, even or perhaps especially in the analog era). [Answer] What makes you think we are not primitive? May be we are still confusing "that something" with technology. Our ancestors found a word "magic" to replace "that something" and later we found the word "technology". Perhaps next generation would find some other word and call us primitives. [Answer] I think the answer yes, but not necessarily in a good way. Lots of people got burned as witches on pretty scant evidence - e.g. none, or perhaps a working knowledge of herbal remedies and an accusation. So it's not that much a stretch when someone's looking for an excuse to be horrible to call it 'evil witchcraft' and get enough people to say that it is. Even today, we have people who believe in things that are a bit lacking in substance or efficacy. Like homeopathy, crystal healing, etc. They don't call it science, but 'mystic forces'. Or at risk of getting a bit contentious - there's still a lot of people who are religious, and believe it makes a material difference despite rather a lack of objective scientific proof. So I think it eminently reasonable that in *any* society, you'll have those who would prefer to 'explain' something by 'magic' than 'science'. The less scientifically enlightened, the greater the proportion of people prepared to do that. [Answer] There are plenty of people, living in our technical age, using cars, phones, computers, who nonetheless prefer a magical explanation for some things. Maybe, when the aliens arrive, these people will choose to build a religion around them. [Answer] There are two aspects to your question. (1) could primitive people confuse technology for magic, and (2) could they correctly identify technology as science and not magic. Assuming that they have the concept of magic, then they could easily confuse tech for magic. A door that opens only for a given hand or at the command of it's owner, seeing things from far away, making images appear on glass (or even out of thin air!)..magic. Could they correctly identify advanced tech as tech, even if they believe in magic? That would depend upon their ability to associate cause with effect. Science is the process of developing a verifiable explanation for a phenonema. Which basically means that a mechanical device could possibly be correctly cataloged, but electronic devices would be impossible to identify -- they would have no framework to place the effects in. A glider is easy to identify as a device, the legend of Icarus is sometime before 650BC, from a glider to a plane with propelers is a short step, although how the propellers are powered would be difficult to imagine. Still, possible. A moving and talking holographic image? Ghost or magic, what other possible explanation could there be? Glasses, amazing technology, hearing aide, magic. In short, some things would be easily identified as advanced tecnology, some things would be all but impossible to imagine as anything but magic. [Answer] ## [Magic](http://www.thefreedictionary.com/magic) n 1. the art that, by use of spells, **supposedly** invokes supernatural powers to influence events; sorcery [...] 4. any mysterious or extraordinary quality or power: the magic of springtime. [...] ## [Magic (2)](http://www.merriam-webster.com/dictionary/magic) 1. a. the use of means (as charms or spells) **believed to** have supernatural power over natural forces 2. a. an extraordinary power or influence **seemingly** from a supernatural source b. something that seems to cast a spell ## [spell](http://www.thefreedictionary.com/spells) n. 1. a. A word or formula believed to have magic power. [...] ## [formula](http://www.thefreedictionary.com/formula) 1. an established form or set of words, as used in religious ceremonies, legal proceedings, etc [...] 4. a. a method, pattern, or rule for doing or producing something, often one proved to be successful [...] ## [supernatural](http://www.thefreedictionary.com/supernatural) adj. 1. pertaining to or being above or beyond what is natural or explainable by natural law. [...] ## Conclusion: Using the contemporary definition of the word "magic", any device that, by use of a **word or formula**, **supposedly** does something that is **above or beyond what is natural or explainable by natural law** is magic. If we simplify, "Magic" is just stuff we can't/won't explain - e.g. just listen to the word "Magic" being used in marketing speech. Many contemporary devices fit the bill by that definition. Semantics depend on what word the people from the past would actually use and what the exact meaning at the time it was used would be, but they would certainly realize that some devices are beyond their current understanding, just like they are beyond the understanding of most modern humans. [Answer] Your question would belong with philosophical anthropology <https://en.wikipedia.org/wiki/Philosophical_anthropology> Already ancients rejected metaphysics as "the super-natural" ("beyond-physics"), as Thales of Miletus. <https://en.wikipedia.org/wiki/Metaphysics#Pre-Socratic_metaphysics_in_Greece> It is not easy to agree with René Girard on quite a few important matters, he yet justifiably pointed to the control factor, in human co-existence. <https://en.wikipedia.org/wiki/Ren%C3%A9_Girard> Just as I do not believe in the "super-natural", as well as scapegoating for origins of language or religion (people did not begin talking in the negative, to learn the affirmative only later; wilful commitment remains the emphasis in Christianity), I agree that human socializing can have inconsiderate aspects. Girard on origins of language, <https://en.wikipedia.org/wiki/Ren%C3%A9_Girard#Origin_of_language> Scapegoating, <https://en.wikipedia.org/wiki/Scapegoating#The_.22scapegoat_mechanism.22_in_philosophical_anthropology> Your visitors having showed their technology or magic, the people would think what it makes to their environment and how to control it, regardless of advancement in own civilization. For example, we could agree the US is an advanced country, technologically and regarding the humanities. Would there be a magician or even regular UFO to propose they make Liberty Island tours, non-profit and cash for municipal coffer, only the island would be majestically floating over New York to show the town (not a drop of water spilled, safe landing back in place), it would not matter if you called it magic or technology. The people would want to have own control over the thing. There would be neither worship as gods, nor burning as witches. "Magic" probably always has derived from knowledge. The Magis were specific wizards able to do their thing time and again, in the minds of ancient Romans and Greeks. Ability to repeat a result points at knowledge. [http://www.perseus.tufts.edu/hopper/morph?l=\*ma%2Fgos&la=greek&can=\*ma%2Fgos0&prior=\*ma/gnhs](http://www.perseus.tufts.edu/hopper/morph?l=*ma%2Fgos&la=greek&can=*ma%2Fgos0&prior=*ma/gnhs) Early Wiccas purportedly could read and write, etc. [Answer] The unknown is by instinct something that is a potential threat. Therefore it instills fear and is approached very cautiously if at all. If it cannot be understood by or if the scientific approach doesn't exist, explanations are attempted, often evoking the supernatural. [Answer] Well, just as a simplistic example, earlier today when I was writing about this very topic, when I was saying that the technology in the time period of my world would have been indistinguishable from magic to the same extent that telegraphs, or telephones, or smart phones would have seemed like magic—each more powerful magic than the previous one—to a primitive civilization, I said, “such as pre-technological people,” meaning, not yet having agriculture, the wheel, or even complex tool use yet. I wouldn't have used like Romans or even just post-Neolithic people in general as my example. I would say, if you are holding some kind of mechanism, at least some people will not be entirely convinced that it's magic. If it's small enough to be implanted inside your body or brain and it can be powered by your own muscle movements or the planet's electrical field or something like that, I think most 19th-century tech level or earlier people, at the very least, will be hard to convince it isn't magic. Hell, there're people alive today who would be. And who's to say it's not magic? If you have a technology that can bend spacetime or hack into the laws of physics and rewrite them to your specs, is that in the category of technology or magic? I would classify it as being both, personally. ]
[Question] [ You know the common trope in fantasy. Meteorite iron is amazing. > > My armor is made of sky iron, made for me. A bear's armor is his soul, just as your daemon is your soul. You might as well take him away" – indicating Pantalaimon – "and replace him with a doll full of sawdust. That is the difference. Now where is my armor?" > > > Iorek from The Golden Compass. > > Cold iron is iron found in a pure state (either meteoric iron or an especially rich ore) and is forged at a lower temperature to preserve its delicate properties. > > > Probably from Volo's Guide to All Things Magical (ISBN-13: 978-0786904464), via [this site](https://olddungeonmaster.com/2016/12/02/dd-5e-metals/). And I won't even link to TVTropes. And you probably know how it really is: [![Obligatory XKCD](https://i.stack.imgur.com/ztdh2.png)](https://xkcd.com/1114/) --- What I'm asking here is **how to make meteorite iron superior, in a medieval setting, without magic?**. What changes to reality, especially star system, I need to make? Point by point, what I want is: 1. An Earth-like planet with humans or humanoids indistinguishable from humans. 2. Meteors that could form in the solar system with an Earth-like planet, if there is a way to make them numerous enough. 1. Meteors that actually fall on Earth are best. 2. Could-be-meteors that don't really fall on Earth but are found or suspected in our Solar system are strong second best. 3. Changing solar system is acceptable. Smaller changes are better. 3. By *numerous enough* above I think amount sufficient to equip heroes if the quality would be legendary, or small armies if it would be barely "very good". 4. Of course, it does not have to be pure iron. Or even to contain iron at all. Only similar enough that calling it "meteorite iron" or "star iron" would seem justified. 5. Qualities I seek are resistance to breaking, edge retention, resistance to chipping/notching, ability to forge it thinner, et cetera. Basically, anything that would make clearly superior swords or armors. Preferably both. 6. Last but not least, it must be possible to actually forge it using medieval techniques, and it must be *impossible* to forge something better or even similar using available technology and no meteorite iron. If tech required is sufficient to make modern alloys, it is no-go. Note: Well described and proven impossibility of such meteorite iron also counts as an answer. One I hope I will not get, but one I can accept if that's the case. [Answer] # Kamacite and Taenite [Kamacite](https://en.wikipedia.org/wiki/Kamacite) and [Taenite](https://en.wikipedia.org/wiki/Taenite) are both Iron-Nickel alloys found (on Earth) only in meteorites. Kamacite's composition is in the 90:10 to 95:5 Fe:Ni range. Taenite's composition is from 20% to 65% Nickel. Kamacite, in particular, can form massive crystals. A kamacite crystal listed in [table 1 here](http://www.minsocam.org/ammin/AM66/AM66_885.pdf) had dimensions of 0.92x0.54x0.23 meters, and a mass of 303 kg; plenty of material to make a whole batch of swords. Finding these crystals means that you have found a pre-mixed alloy. There is no longer any need to smelt to mix the alloy. The crystal can be directly worked into a sword via the normal methods. The melting point of both kamacite and taenite is not significantly different from iron, so normal, time-period appropriate methods of swordmaking would be valid. # Hardness Hardness is the resistance of a blade to *strain*. That is, when a force is applied, how resistant is the material to deforming. A harder blade will cut through a softer one (or wood or bone) without getting blunted. Both these alloys have a hardness advantage over regular iron. A study of 22 siderites (Iron-Nickel meteorites) reported on their hardness in [Table 1 here](http://onlinelibrary.wiley.com/doi/10.1111/j.1945-5100.1947.tb00031.x/pdf). For a comparison, we can use this [study](http://www.ecs.umass.edu/~arwade/iron.pdf) of wrought iron sampled from 10 bridge built in Massachusetts in the 1800s. The average [Rockwell B hardness](https://en.wikipedia.org/wiki/Rockwell_scale) of 24 meterorite samples is 81; while the average from 53 bridge components is 58. The 95% upper limit for the bridge iron is 72; 92% of the meteorite samples had a hardness greater than this. For a comparison to more modern materials, matweb.com's database has information of 176 types of [high carbon steel](http://www.matweb.com/search/datasheet_print.aspx?matguid=ee25302df4b34404b21ad67f8a83e858). The average Rockwell B hardness is 95.7 over the range 43-100. Rockwell B is a hardness test for softer materials, so it doesn't scale well to harder materials. For example, the difference in theoretical hardness between 95 and 100 is much larger than the difference between 40 and 50 on the Rockwell scale. For a better high hardness test, the meteorite study includes the [Brinell scale](https://en.wikipedia.org/wiki/Brinell_scale) as well. The average Brinell hardness is 169, but with an upper limit of 330. 9% of the samples have hardness over 230. This variance in hardness may be a result of the shocked vs. unshocked nature of the crystals. Unshocked crystals evidently have hardness about 50% higher, according to a Wikipedia statement that I cannot verify. Unworked iron has a Brinell hardness of 110-120. This is the base material from which a sword is made, so a kamacite alloy can start two or three times harder than pure iron. The standard measure from blades is the Rockwell C test. The Rockwell C hardness for [three Damascus steel blades](http://www.tms.org/pubs/journals/JOM/9809/Verhoeven-9809.html#Ref13) from ~1750 are given as 23, 32, and 37. This [chart](http://www.carbidedepot.com/formulas-hardness.htm) converts those values as 240, 300 and 340 on the Brinell scale. A summary chart ([Graph 1 here](http://myarmoury.com/feature_bladehardness.html)) shows average example blade hardness from 8 swords that convert to 130, 170, 180, 190, 210, 260, 400, and 440 on the Brinell scale. For modern materials, [cast iron](http://www.matweb.com/search/datasheet.aspx?matguid=ec56a89f37f74e2f867a64b0f87f1e9d) has a Brinell hardness of 183-234 and high carbon steels from 163-600 with an average of 262 (over 207 different types). So it is possible to find a meteorite alloy that is harder than some modern high carbon steels and as hard as high quality Damascus steel blades. Perhaps 10% of the iron-nickel meteorites you find will be of the un-shocked high hardness variety. A [modern tool steel](https://acta.mendelu.cz/media/pdf/actaun_2013061010025.pdf) forged into a Damascus type blade had hardness of over 700. # Strength Strength is the ability to withstand deformation. The integral of strength over deformation distance is toughness. While a hard blade might not deform upon being struck against a stone wall, it might fracture. A tough blade will deform (getting notched, or bent slightly) but won't fracture. The data for stress-strain curves for meteorite samples is not available (to me, at least), so instead of toughness I am using strength at comparable strains. The [Gibeon](https://en.wikipedia.org/wiki/Gibeon_(meteorite)) iron-nickel meteorite [was drawn into a rod](http://adsabs.harvard.edu/full/1970Metic...5...63K) with a tensile strength of 392 MPa and a compression strength of 373 MPa. For a sword blade, compression and tension strengths would be similar to each other. For a raw meteorite alloy, the kamacite meteorite found in [Canyon Diablo](https://en.wikipedia.org/wiki/Canyon_Diablo_(meteorite)) had a compression yield strength of 424 MPa with 0.2% compression (that means it only deformed by 0.2% of its initial size); tensile strength should be similar. The comparisons here are to modern cast iron, with a tensile strength of less than 276 MPa. High Carbon steels have a range of tensile strengths from 161-3200 MPa with an average of 1010 MPa over 219 types. The ratio of tensile to compression strength can vary by application. Manually puddled [wrought iron](http://nvlpubs.nist.gov/nistpubs/jres/3/jresv3n6p953_A2b.pdf), made and reported in the 1920s, had tensile strengths around 165 MPa at 0.2% tension. The bridge samples averaged yield stres of 230 MPa; all samples yielded below 0.2% tension. An investigation of iron products made in a replica of a 10th century forge had yield stress from 300 to 500 MPa with yield elongations between 0.05% and 0.4%. Ancient [Wootz steel](http://materials.iisc.ernet.in/~wootz/heritage/WOOTZ.htm) swords were found to have yield strengths in the 800-1500 MPa ranges. Modern steels forged into layered Damascus steels were found to have yield strengths around 1200 MPa at 1.3% elongation. Overall, we can see that the compression strengh of the meteor iron is lacking in comparison to modern materials or the finest Damascus steel, but competitive with medieval forge products. # Conclusion The alloys found in iron-nickel meteorites had properties that would have made them competitive as blade making materials. For hardness, un-worked meteor crystals had hardness equal to the finest Damascus steel blades, close to the finest of any blades, and significantly higher than wrought or cast iron. This material is un-worked; the raw alloy has a hardness advantage of two or three times on un-worked iron. Presumably there is quenching and tempering process that can increase the raw material's hardness by another factor of two or three, just as ancient steel blades are up to four times harder than raw iron. Toughness is greater than the iron products that would be common in everyday use, but not as great as the best steels available. Toughness is equivalent to iron sword products made with 10th century technology. Overall, I think that you could reasonably expect a 'just right' Iron-Nickel alloy meteor to contain large, pre-alloyed crystals that could be forged into swords. This alloy, if annealed just right (through luck, the assistance of the Gods, or however the smith acquired the right knowledge) would make a blade strong enough to be usable, but harder than anything available until the 19th century. [Answer] Don't make space iron better. Make all other iron worse. Read up on [Low Background Steel](https://en.wikipedia.org/wiki/Low-background_steel). Have all of earth's iron contaminated with something, and less useful than we think of iron being. At some time in the past, there was a cataclysmic event which contaminated all iron with something. Maybe the Elder Gods awoke, and their presence cause decay or corruption of all steel or iron. Only meteorites that have landed since then remain free of this imperfection. As with low background steel, you could argue that items already forged into steel were safe from this corruption, making meteorites and ancestral relic swords both viable, but anything forged new is poor. [Answer] *Some* meteoric iron can make for very nice weapons, you can go buy some now. In the medieval period most places couldn't actually make great weapon steel. Many swords (where the quality of the steel and the style of manufacture is more important than in an axe head or spear point) came from just a few places/forges, or at least the metal was sourced from a few areas that could produce quality sword steel. So not any old blacksmith could hammer out a quality sword even if they had the right base metal. So for you, the area the heroes are in simply doesn't have good quality iron ore stores and no one really knows how to refine what they do have (look at crucible steel, Japanese pattern welding, and Damascus steel for examples of very technique specific/location specific steel sword manufacture). So meteoric iron from a few meteors with the right metallic components could very well be the only source of quality sword steel. To source most of your iron from meteors would be problematic, it would mean that the tectonic activity of the planet itself, as well as it's construction, is substantially different from Earth, and lots of falling meteors depositing metals tends to not make for an environment suitable for advanced civilization (or any civilization, really). Obviously you can handwave this with magic (maybe a high metallic content moon was shredded in an ancient war and rained down on the planet?) or with just ignore it completely. In your world, or at least the area the story is set in, ground deposits of iron are very scarce so meteoric lodes are actively searched for and fought over. Of course in this area swords probably wouldn't be particularly popular and other weapons would be more prevalent (which was generally true for most of the historic medieval period anyway), swords that were around would be cherished heirlooms and the sword fighting techniques would be restricted to those nobles with access to swords in the first place. It is also worth noting that the origins of "cold iron" supernatural properties probably start well before the iron age, when meteoric iron, even poor quality, was probably superior to the bronze metal used by everyone else. There is little to suggest that meteoric iron would be superior to what a medieval smith could produce from a good sword smith shop that had access to good terrestrial iron. [Answer] **Iridium iron: Chengdeite.** <http://www.galleries.com/Chengdeite> > > Chengdeite in fact is only beat out by minerals that are more enriched > in iridium and/or osmium; specifically the minerals iridium, osmium > and iridosmine, an iridium/osmium alloy. Iridium, at a calculated > density of 22.65 grams per cubic centimeter, is probably the densest > element known to man. > > > Iridium is more common in meteorites than it is in earth's crust, probably because it is so freaking dense any iridium on the planet is in a lump in the center of the core. The high iridium content of the geologic layer at the end of the Cretaceous is what gave a hint that a meteoric impact might be involved. Iridium is three times more dense than iron and [three times as hard](https://en.wikipedia.org/wiki/Hardnesses_of_the_elements_(data_page)). It is so hard that it is very difficult to process; to my understanding the main use of iridium alloys is for dies which do not wear away as they process huge amounts of steel wire. Your sword of iridium iron would be like Odysseus' bow or Thor's hammer - three times heavier than it appears to be and so requiring preternatural strength to wield. The extreme hardness would mean extreme sharpness, and I suspect sharpening stones adequate for terrestrial weapons would not sharpen this celestial sword - you would need garnet or maybe sapphire. Your meteorite sword would be very heavy, very sharp and nearly unbluntable. [Answer] @kingledion has the best base reality answer. There was a scy phy Beowulf crossover I saw. Where the crashed space traveler forged part of the hull of its ship to destroy the alien monster (Grendal) that escaped from the crashed ship. A crashing space ship could easily be seen as a falling star. And depending upon the space ship design, its hull could be superior to standard iron/steel. <http://www.imdb.com/title/tt0462465/> **Note** This is most likely an aluminum alloy or titanium based on current earth space tech. However I haven't been able to find the specific alloys used in the Space shuttle. [Answer] the main advantage of meteorite iron is it is far purer than the vast majority of earthly sources, and removing impurities is the single biggest limitation is the strength of early steel. It is really hard to make quality steel when you don't know what is in the iron to begin with, especially things like silica, oxides, and carbon, the things iron rich meteorites have very little of. The forging is still the same (maybe a bit easier since you don't have to do excessive folding) but it is the turning of ore into usable metal that is much easier. Better raw material often translates into a better finished product, the steel has the same properties throughout, not mixed mess full of weak points. Compared to modern steel meteorite iron is crap, but you need industrialization and advanced chemistry to make modern steel. Compared to the bog iron and bloom steel of the time it is wonderful and until advanced smelting techniques (crucible steel, ~8th century) and high quality ores are discovered it is the best raw material available. So up until around the 6-8th century meteorite iron would have been better than anything and would stay better than most for quite a while afterwards. [Answer] Metallurgy and biology to the rescue: **your characters' usual enemies are severely allergic to nickel** (or have some other really bad biological reaction to it). Meteoric iron, despite the name, is actually an iron/nickel alloy. Even in the real world, people with nickel allergies often have trouble wearing alloys of nickel as well. If your enemies have particularly terrible reactions to nickel, then meteoric iron (to say nothing of pure nickel) would essentially be poisonous to them. The more realistic skin allergy might still be present in some people, and even arouse suspicion. If your culture mirrors medieval Europe, then they likely do not have the technology to melt or smelt nickel: the temperatures required are simply too high. They might not even understand that nickel is a distinct metal. But the effect of meteoric iron on an enemy poisoned by nickel would be all too apparent, and may give rise to meteoric iron's reputation as a mighty enemy-killer, even as the relatively low level of technological advancement prevents them from making their own. [Answer] Set your civilization in the bronze age. Iron (or steel) doesn't exist except for what falls from the sky. No one even knows what "iron" is, that it can come from the earth or how to extract it from the earth (hematite and magnetite) [Answer] Metallic meteorites are made of iron nickel alloys. Iron has been made from terrestrial ores for a few thousand years but nickel is pretty hard to get. We didn't isolate it here until the 1750s. Meteoric iron has average 10% nickel but can be 25% or more in some cases. Cobalt is the main other constituent at about 0.5%. Nickel steels have several desirable properties. You can make low C steel with a few percent nickel content that has significantly higher elastic and fracture strains than unalloyed steel. Meanwhile it doesn't change the Young's modulus, so the material ends up having higher strength and toughness. It would also somewhat resist corrosion. The extreme example if this is called maraging steel, containing 15-25% nickel (but cobalt than almost all meteorites) which can be made to have remarkable strength at high toughness for aerospace applications. Sport fencing foils are also made of matching steel for its fracture resistance. If you use a really high nickel steel it can be made stainless. It'll be reasonably soft so not blade material, but you can plate a sword with it and make it mostly corrosion resistant. It would stay bright and sharp even in humid environments. This would be pretty amazing to medieval people. If you're willing do slightly stretch astrophysics then somewhat higher Co content in meteorites is plausible. With the help of a sufficiently wise wizard (metallurgist) the production of this material may be plausible with medieval infrastructure. Heat treatment and controlling impurities will be the important knowledge. You can frame meteorites as a starting material for maraging steel. This would be a superior sword core steel with remarkable strength and toughness. It's low in carbon so it's not very hardenable so the edge should be high carbon steel forge welded on. This would be especially valuable in a context where high carbon steel is hard to make (which is true in most medieval societies.) This stuff is fine for swords but it would be amazing for armour. Especially plate armour where buckling resistance is sought. That's exactly what it's used for in missiles and aircraft. I think a cool concept is to apply people with modern knowledge (wizards) to a low tech medievalish society and see what they can do. [Answer] Some good answers here already, but how about this: There is no other iron on the planet. So meteorite iron is the *only* iron, from which skilled smiths can make steel, which obviously beats the crap out of the bronze weapons otherwise available. In a world where steel doesn't otherwise exist, its strength, hardness and resilience would seem pretty magical. [Answer] Most meteoric iron also contains some varying amount of nickel. Iron-Nickel alloys are stainless steels with varying levels of corrosion resistance, and are typically less brittle then straight steel. Several other trace metals can be added to further increase varying degrees of corrosion resistance, anti-rusting, or toughness. One way to make such weapons desirable would be the setting that your swords are used. Do the enemies have corrosive blood? Maybe meteoric blades don't dissolve into nothing after a killing (bloody) strike. ]
[Question] [ The eventual heat death of the universe is an awful time to be alive considering you wouldn't have long left after the last star finally fades away. In this scenario there is a small group of about a dozen human survivors who live in a colony on an earth-like planet that orbits the last star to burn out. The group know of their impending doom and have time to prepare for it, about 10 years (but feel free to adjust this time if you think of something cool). Now I fully expect answers that lead to the eventual death of everything from this scenario but what would this group need to do in an attempt to continue existing for as long as possible in a universe with no heat? **Note**: This would be trillions of years into the future so feel free to go a little crazy with future science, as long as it makes sense. It would also be interesting to see how a race of humans with current-day technology could survive in the same conditions. [Answer] **Get out** I mean, literally. As in "get out of the universe". The heat death of our universe is by definition not a survivable event. That's the bad news. The good news is that it takes a very, very long time to happen. So a technological society has time to develop technological solutions to the problem. Some things that might work are: 1. **Cross over to an alternative universe.** Multiverse theory is endorsed by a surprisingly large number of prominent physicists. So let's assume the physicists are right, that multiple universes exist, that at least some of them still have a few trillion years left in them when our universe is grinding to a halt, and that science has advanced to the point where it's possible to travel between universes at will. Why struggle to survive in a dying universe when you can just move next door and start over on a new planet? 2. **Return to a previous time in the current universe.** So multiverse theory didn't pan out despite its prominent endorsements; who cares? Perhaps wormholes are real and capable of traversing both space and time. If they are, it's plausible that a technological society will learn to control them before the universe's heat death occurs. And if they do that, they can use them to travel to any desired place and time within the current universe. So they can just pick a more hospitable moment in time, and go there. But might lead to interesting cyclical dilemmas as repeated generations keep jumping back in time to avoid facing the heat death of the universe (only to find some subsequent generation already camped out in their chosen real-estate). 3. **Jump in a black hole.** So both multiverses and wormholes turned out to be fake; guess we're screwed. But no need to wait around to die an icy death. Instead find the nearest black hole (or use your stockpile of doomsday devices to create one) and jump in. At least you get to go out on your own terms. And who knows, maybe black holes are actually survivable or will transport you to somewhere a little less doomed. If nothing else, it won't be boring and perhaps relativistic time dilation will give you a good view of the universe's final moments. **Invite some guests** Kind of an inversion of the previous approach, but maybe multiverses do exist but we're not able to safely transport living things from our universe to another. That doesn't necessarily mean we can't snag a fresh sun or two every now and again. You know, just enough to keep a tiny ember burning in our universe. Heat death doesn't occur until you reach maximum entropy, which is something that you can hold off indefinitely if you're able to pull in even relatively small (say, on the order of an M-class star) clumps of matter every few billion years. If you've got the technology, and a power source for it (the big question is whether it can be possible to pull a star from one universe to another using *less* energy than the star will generate over its useful lifetime), you can wait it out. Come to think of it, you can wait it out regardless since the heat death of the universe can't occur until well after any warm-blooded life forms have ceased functioning. The most you can ever observe is the prelude. [Answer] **No.** By definition the heat death is the state where you could no longer do anything. Any actions you do before it only makes it come sooner. **Best strategy:** Sit still, do absolutely nothing. (I kinda like this strategy) For high-tech civilizations I recommend you put out the stars. They produce entropy really fast. In general, stop things from changing. Transforming energy from one form to another always produce entropy. (the "heat" in heat death). To survive as long as possible you must minimize the consumption of energy. [Answer] **Hard physics answer** I think the question is fundamentally ill-posed. As long as there are humans alive somewhere, the universe is millions *to the power of millions* of years away from the "heat death" (which is not at all an agreed-upon or well-understood thing). The heat death (if we assume it is well-defined) is definitely not "when the last star fades away". It's waaaay later than that, at least after the final supermassive black hole has evaporated due to Hawking radiation, which would take on the order of 10$^{100}$ years after the last star dies. [Answer] **Hack the Universe** The universe is just a simulation running on a super computer somewhere. Exploit a bug so that you can get more energy/matter. [Answer] I think the question implies a paradox that can't occur. The heat death of the universe is not when the last star goes out, it's when the universe reaches maximum entropy. By definition then, there's no way of 'surviving' the event, because you'd have to be dead in the first place for the condition to have been reached. Dead, decomposed and the energy you released into the ground dissipated universally. You get the idea. But lets assume the question is: can a civilization survive the extinguishing of the last star. Well, yes. Aside from any local reserves of fissile material, the planets themselves are still orbiting, so there's still masses (sic) of energy sitting in gravitational wells, waiting to be harvested. And that dead star is still rotating the galactic center, and that's still caught up in some amazingly long range interactions with other galaxies. And so on. Extracting usable work from all this energy will be a significant challenge however, but if the motivation is there... [Answer] Depends on your **exact definitions and assumptions**. First you are assuming "heat death" as the [Ultimate fate of the universe](https://en.wikipedia.org/wiki/Ultimate_fate_of_the_universe). There are other options. Secondly, the last star burning out is [FAR from the heat death of the universe](https://en.wikipedia.org/wiki/Chronology_of_the_universe#Ultimate_fate_of_the_universe). * 1014 years - last stars burning out * 10100 years - last black hole's evaporate * 101000 years - heat death The ratio between number of years in your scenario and the actual heat death is a 1 followed by about 986 zeros. You're a bit early. The classical physics definition of "the heat death of the universe" is the moment when the universe reaches "[thermodynamic equilibrium (AKA maximum entropy)](https://en.wikipedia.org/wiki/Heat_death_of_the_universe)." which means that there are "no net **macroscopic** flows of matter or of energy." Let's presume that the universe refers to the entire universe and not just your personal "[observable universe](https://en.wikipedia.org/wiki/Observable_universe)" for simplicity's sake. Note that there are numerous theories and wild ideas in physics that suggest that either this point would literally never be reached due to other events or that it would decrease again afterwards and thus multiple heat deaths might be possible. Note above the word "**macroscopic**". There is, in practice, a lot happening below that scale and if you accept the concept that life can be realised as dynamic information, then it is possible to assume that after many, many trillions of years of technological advances we might figure out a way to live down there at that scale. We might not even notice the heat death occurring? (Oh, was that this week, I though I set a reminder...) If your civilisation has access to **sub-macroscopic** technology, then by definition you can use any **sub-macroscopic** based escape path without blocking the heat-death. That could mean living down there at that scale or transporting yourself to a different universe. [Answer] Learn to control time. While another poster suggested "jumping back" to previously stable points in time, it is worth mentioning that *we don't really know what time is.* Therefore, there are properties and functions of time with applications that we aren't even aware of yet. For example, once you can control time, you can probably exert some control over space-time. Infinite control means you could craft physical laws that recirculate energy throughout the universe in a predictable format, like a river with walls. This could be a corollary to Einstein's "Cosmological Constant," where the universe expands as it does now, contracts a bit to harvest and recirculate the energy, expand again, and so on. Two issues, however: 1: The energy required to exert sufficient control over space-time may exceed the available cosmic energy required for infinite existence. 2: Space-time control could have "leaks" of its own, resulting in the same eventual heat death. You could still get a few trillion-trillion years or so of existence, which ought to help a sufficiently advanced civilization come up with a more permanent solution. As a final note: we are considering options based on *what we know today.* Thomas Malthus predicted the end of civilization as population exceeds resources, however he lived in a time when the primary economy was making food and the primary fuel was food and muscle (livestock, slaves, etc). It is unlikely he could have foreseen a future where robots harvest crops from year-round solar-powered greenhouses. It is therefore reasonable to expect that our limited understanding of the universe denies us the vision to see solutions beyond the tools we are aware of. Given how long humans have existed and how little the time, in geologic terms, it took for us to go from hunter-gatherers to the Information Age, I suspect that if we can avoid nuclear, environmental, or biological apocalypse, we will figure it out in time. [Answer] There's an odd mathematical construct you can strive for, to survive as long as you need. The key is that heat death is not an event, but a slow predictable decline in energy. If you can accurately measure how much usable energy you have (lif you have to err, err on the lower side), and you can spend energy proportionally to that amount, you end up with an exponential curve of dwindling energy, which mathematically never ends. The tricky part is when you are dependent on processes which are not proportional like that. For example, we are currently very dependent on activities which rely on quantized behaviors, such as the emission of photons. Those events will have to be more and more rare as the energy levels decrease. You would also likely choose to concentrate your energy in a smaller and smaller portion of your space, in order to permit at least a small portion to be using such quantized energy. In fact, this has lead to two competing extremes as to how to accomplish this goal. There is the continuous process, where you try to keep a fluidly decreasing amount of energy usage, and the discrete approach, where you subtly collect energy for as long as needed to permit one quick burst of a finite length of energy. Presumably whatever the final solution will be will involve a cross between both of these approaches. The hard part is knowledge of the heat death: you don't have it. There is no way for science to *know* that heat death will occur, as opposed to us discovering that our mathematical models which proved heat death will occur were wrong. Sure in our 359 years or so of modern science and thermodynamics, we're pretty sure that's the direction things go. We have another 10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 years before galaxy sized black holes vanish, and I'm not even going to write out all the zeroes in the $10^{10^{56}}$ years before quantum tunneling might start poking holes that let us into other universes, by our theories. We have a long time to find out that we have an incomplete theory. The hard part will be not developing a survival scheme that *assumes* we've seen it all, and starts down the path of exponential decay to live forever like Nietzche's Last Man. We would need to continue to reach out and observe the dying universe, looking for hope. If we find it, we need to be about to harness it to build the best world we possibly can. You can imagine how horrible it would be to find that there was a god like physical entity just outside our perception, nurturing us along, only for us to give up on ever joining them. More interestingly, the smaller the civilization gets (as heat death looms), the smaller such an entity could be and still be perceived as having godlike powers! When the universe is facing proton decay, and a civilization is trying to simply hold onto the tiny quantum blurs that keep it alive, imagine how powerful you or I would seem, happily collapsing trillions of waveforms every moment just to pick up a glass of water, nevermind the trillians of irreversable chemical reactions going on in our synapses to feel like we are thirsty. Thus, the balance. The more energy spent exploring the world outside, the harder it is to maintain an eventual exponential decay to live forever, but if you squirrel yourself away in exponential decay, that's all she wrote. You have to strike the balance between the two. Fascinating how life itself has a tendency to be able to balance the nuances of continue procreation for an astonishing number of generations, while never ignoring the world around it, constantly evolving based on new observations and discoveries (even if those discoveries are simply radiation breaking DNA strands). Perhaps it is life itself that will one day strike this balance. Imagine what life could do if it reached out into the quantum world, instead of being shackled to classical physics. Maybe the Gaia theorists are on to something. [Answer] # Not previously addressed issue: Due to the [acceleration of the inflation of cosmological space](https://en.wikipedia.org/wiki/Dark_energy) there exists a point in time where the expansion of space *exceeds the speed of light.* In such a universe there may still be particles flying around and light zipping off in Directions and stuff still "happening" but space is inflating so rapidly that even *photons* cannot interact with each other, much less anything else (causality is limited by the speed of light). In such a universe, matter as we know it cannot exist. Your heat death colonists will find their bodies being ripped apart by the sheer inflationary aspect of *space itself* (assuming somehow remaining intact until this point). Notably this effect will likely cause problems long before the rate reaches the speed of light, but I am unsure how much sooner, or when it occurs relative to classical Heat Death. I can only say for certainty that such a time exists where nothing can interact with anything, and that is currently not the case, ergo a point in time exists between these two extremes where atoms, molecules, and larger structures themselves will be torn to shreds by the expansion of spacetime as it overcomes the bonds holding things together. [Answer] The answer not yet mentioned: don't do anything, just wait until the random fluctuations bring the Universe arbitrarily close to your current state according to the [Poincaré recurrence theorem](https://en.wikipedia.org/wiki/Poincar%C3%A9_recurrence_theorem). In fact, you will return infinitely many times, that means you cannot be sure you are not already beyond the previous heat death. It is indeed very probable. [Answer] ## Create (simulate) a new universe Similar to the "Hack the Universe" answer, but instead of exploiting a bug within the current universe, just create a new universe within the current universe. Scientist will have a lot of time before the heat death of the universe to create faster and faster supercomputers and will be able to create a computer so fast and powerful that it will be able to simulate an entire universe (and do it more efficiently than the real universe). The computer could simulate events of a universe at a much higher speed than the current universe. In this way, one year in the real universe could be the same as thousands of years in the simulated universe. And during this time the scientists can find ways to improve the speed of the simulation, making it lasts millions or billions of years longer. [Answer] 1) more blankets. 2) go to Milliways. 3) the question itself really means nothing. It has massive implied circumstances that are hidden in the choice of words: * what does "survive" mean? * for how long? * in what form? * what else exists that you survive into? back to the physics first: "heat death" is, as someone notes, achieving maximum entropy. That means that every piece of matter in the universe (and it's all still here, if it hasn't been converted into iron and energy by fusion), has reached background radiation temp (currently 3 deg Kelvin, not 0). Energy cannot dissipate any further, because it has gone as far as it can go. It can't be destroyed (remember that from grade school science), so it has achieved flat uniform distribution over the entire universe. For that to be true, "you" have dropped to 3K as well. So you aren't alive, in any sense of "alive" that we currently think has meaning. But of course "you" ("we") have already long since moved beyond having a corporeal existence, so "atoms" aren't interesting any more. we have no current understanding of "dark matter", or "the inside of black holes" or "the inside of quasars", who knows what other exotic phenomena exist? and this question suffers from incomprehension consider that we can't even imagine what the other side of the sci/tech singularity is going to look like: in another thousand years, if not sooner, we aren't going to be "human" any longer, in the current sense of humanity. What is *that* going to mean? (this, I think, is a central failing in science fiction, which I read a lot of: in a story set hundreds or thousands of years from now, people haven't changed a bit. Seriously? I get that it would be impossible to write a comprehensible story about those characters in terms we could understand today, but really, way too much SF has characters essentially from "today" transplanted into a new/different setting that will actually be WAY more exotic than a person from Pittsburgh going to Mexico City. one additional thing: in a continually expanding universe, with a fixed amount of mass/energy, the background temp will drop over time, so that what we measure as 3K now will go down, but it can't ever reach zero, because that would mean the universe stretched to mathematical infinity, which isn't possible. and other basic physical forces would still exist. If the universe reached 3K, does it then begin to collapse? Gravity isn't going to go away. relevant stories: Tau Zero, as mentioned...In Iron Years, Gordon Dickson. Neither address the original question, but are interesting sidebars [Answer] First solution: stand still and await your fate, there is nothing you can do when the only thing in the universe is one $0K$ iron atom$/500km^2$. Second solution and since they manage to keep an hearth-like planet until this time, well they might get energy out of nuclear reactions of it's constituent. Everything that is not iron can release energy that way. Then when you are out of dirt start to use other people, when you are out of people well use your limbs, when you are out of limbs you are officially doomed. Note that heat death is an absolute end, all you can do is delay the inevitable. Other solution: dualism. If the soul is immortal and does not need energy you bypass the question. You can make a story about ascending to that state to "survive" the end of the universe. "you gotta use a magic stick": find a way to change the laws of physic through whatever technology. Entropy in a closed system CANNOT decrease, wave your hands and remove entropy. "It's not heat death yet": transform iron into anti-iron, spoof magic: direct mass to energy conversion. you just got a couple quadrillion years before there is effectively no matter left in the whole universe. Last solution: reverse the flow of time? that's the only way you can decrease the entropy of the universe without rewriting physic and since time travel is common in sci-fi I guess that could be a good solution. You can as for example create a time loop where the end of a day is the beginning of the same day. [Answer] # Embrace the Cold! So the universe is going cold, right? Abandon all of your current concepts of life and humanity and become one of the *Cold Ones*, creatures able to survive, nay, thrive in this new cold universe without heat or entropy! Make them hardy enough to thrive in the cold between dead stars and maybe even sturdy enough to survive a big crunch/big rip scenario, possibly surviving into the next universe. If they do make it that far, do they embrace their anti-heat/anti-entropic nature or go back to being warm humans? [Answer] # avoid it With all energy sources run out, you can still keep a prepared system that's in equilibrium. There is a concept called [*reversible computing*](https://en.m.wikipedia.org/wiki/Reversible_computing). Random changes can make the calculation run forward or run backwards. To ensure progress you need some tiny sink of entropy, and maybe this can still be found using some quantum vacuum phenomena, or some symmetry-breaking operation. But even if no such loophole exists, you literally have forever: the calculation will progress forward and backward at a random walk, at *some* point proceeding forward arbitrarily far. To the software entity, he still thinks and experiences time. But his time runs forward and backward in a random manner: thinking thoughts and laying down memory, then un-thinking and restoring memory to the earlier state! But eventually it gets forward, and reoccuring the exact indistinguishable state is no different from having it exist only once. [Answer] Aquire a Cosmic String(no relation to the strings in string theory.) Cosmic Strings are an extremely rare topological defect that are narrower than a proton, but light years long. They are incredibly dense, causing extreme space time distortion near them. By finding one, spending several billion years traveling to the nearest one, and then somehow grab both ends of the string, cross them over each other to create a loop(though probably a much more complicated pattern), and then pull them together at relavistic speeds to close the loop, and then fly a ship through the loop at exactly the right speed/angle, you **might** then manage to make a closed timelike curve and travel to a younger universe. <https://arxiv.org/pdf/hep-th/0502242.pdf> Of course, the paper says that even a *single graviton* is enough to destabilize the ctc, so good luck. [Answer] The stars might be gone, but the photons they emitted during their life will mostly still be traveling in the universe. To get energy you need photons, not star. Build huge mirrors, send them out in the universe with FTL spaceships and harvest the light they send back. By wisely scattering the mirrors over several distances you will get plenty of energy for about the same age of the universe [Answer] **Conserve energy** Our future ancestors have invented a way of preserving energy in super batteries that don't discharge over time! They created a network of colonies in which we incase all stars with dyson spheres that let the colonies utilize their star systems energy meanwhile sending their spare energy to the central government as a tax. Once heat death is impending and colonies cant move to another solar system since all stars are "going out" we will all migrate to the central government,create a planet of our own which its core is literally a huge battery. A floating space sanctuary containing the energy of a couple billion stars. We will just breed and mess about on our planet-writing poetry and living life. [Answer] **Don't worry be happy** Nothing will actually happen because the past is just as real as the present and the future. So, the universe in the heath death state just exists out there just like the early universe and the universe in the state we experience today. When faced with the prospect of dying, what will actually happen is that you'll survive with memory loss about that fate, you'll most likely end up somewhere back in the past where the things that you now consider as already having happened, haven't actually happened from that other perspective. These are just possible things that could happen in the future. Also, the outcome of these events doesn't have to be the same, as we're living in a quantum multiverse. [Answer] ## Don't worry about it - there's nothing to "survive" Why? Well, we know that entropy always increases with time... but we're [still not entirely sure which is the causal relationship](http://io9.gizmodo.com/5667872/does-entropy-increase-with-time-or-does-it-make-time) - it could be the case that what we think of as 'future' is *because* that's the point where entropy has increased. And so just as there wasn't any such thing as 'before' the big bang, there is no such thing as 'after' the heat death of the Universe - time will have 'run out'. Think of it like a clock winding down - it runs steadily slower and slower, until it stops entirely... but the clock hasn't vanished, it's still right where it always was. So really - there's nothing to survive, because it doesn't actually *end* - we won't perceive the ticking slowing either, because our temporal perception is 'locked in' at 1 second per second. One day, everything will just stop entirely, about the point where the Universe turns into a rather cold and thin soup. This is an extremely long way off though, as almost by definition - the very existence of a person means there's quite a lot of 'unspent' entropy left. [Answer] I didn't see this in one of the other 20 (!) answers: You cannot avoid the eventual heat death, but you can *postpone* it for yourself. Build a self-sustaining spaceship as your last home, board it and accelerate it as close to lightspeed as you get, closer and closer. You will live "forever" because of time dilation. There is a requirement, and a problem. The requirement is that there must be sufficient energy available to build such a ship, and to create the high-energy fuel which is needed to propel it. But because you have a planet orbiting a sun, there is *plenty* of energy. (BTW, I'm not sure how you arrive at a time scale of 10 years if you still have a whole frigging solar system, no matter how old ist sun is. The more "realistical" scenario is that the last black hole within reach is about to evaporate. No stars, no planets, just background radiation everywhere else.) The problem is that "self-sustaining" is an unreachable ideal. The ship leaks energy, actually at an alarming rate while it is being propelled. The days of the crew are therefore numbered, because obviously there is no gas station anywhere. What's being extended is their life span *measured from the "stationary" universe.* If they get close enough to lightspeed they'll see much more of the universe's history than if they had stayed in place. (A history which is boring though.) Their life span in the spaceship as it is individually perceived is actually (much) shorter because they are burning all this valuable energy in their lighspeed drive. They could have used all the energy much more efficiently in a well-isolated stationary survival station, and survived for eons harnessing the kinetic and gravitational energy of their solar system, long after the sun had burnt out. Perhaps you can make the group split, and in the end the space-farers come back and re-unite with the descendants of their fellows back then. [Answer] ## You can't, but not in the traditional sense. The last star burning out is not even close to the heat death of the universe. There is zero distance in heat at all; there is no temperature difference, and thus you cannot perform any work. Essentially, the universe is in thermodynamic equilibrium. (Perfectly balanced, as all things should be?) The last star burning out is several orders of magnitude earlier than the heat death of the universe. After the last star dies, there will still exist billions of nebulas, planets, and other relatively static objects. The fact that humans are still alive in your scenario (assuming normal humans) implies that it's been under 100 years since the star burned out. The heat death of the universe is far away. [Answer] # Develop Superintelligence First > > *the only thing that makes sense to > do is to increase the scope and scale of human consciousness* > - Elon Musk > > > The perspective of the human species will change dramatically in the coming centuries as it has in the 20th century (Before 1923 we thought our universe was just the Milky Way.) Only last year Svante Paabo sequenced the Genomes of Neandertals and Denisovians. Sentient humanoids that roamed Europe 40 000 years ago. Many secrets still remain out there in the darkness of "unknown unknowns". If we unlock the secret sauce of how our brains work. We will know how to increase our "intelligence" significantly and use the increase to further increase our intelligence. Our Superintelligent descendants will understand Physics much better than we do. In the mean time let us focus on reaching the critical mass of science, technology and wisdom required. [Answer] What if time was circular and life goes around the wheel of time. Space and time could be virtual and perception is the pointer on the space time co-ordinates. Ahh! the illusion of the expanding Universe, expanding into what? where will it expand into and what if the universes of a multiverse collection were all expanding at the same time? Would there be space for any to expand? Or would they slide under on into another universe via a black hole (or some other construct) much like tectonic plates do? Our understanding needs to expand to understand the expansion of the Universe... Also our observations have a time lag limited by the speed of light and the limits of our knowledge and tools. Aren't humans part of the Universe? How could they Universe have a heat death when humans have heat in their bodies? Maybe it's the death of the Universe due to high heat much like a heat stroke? [Answer] ### Create a new universe. One cannot (by definition!) survive the heat death of the universe. And there may be no others to goto, and time travel into the past before the time machine was made may not be possible. But one might be able to create a new universe. I have had the idea that "The Big Bang has happened before. It can happen – or be *made* to happen – again". This is based on various ideas, such as the one by Stephen Hawking (in an older one of his books) that the Big Bang was triggered by a spontaneous fluctuation. The key idea behind this is that cosmic inflation could produce the entire (currently) observable universe from a tiny amount of matter. Furthermore, in this model, the Big Bang can be triggered. Since our protagonists have had literally trillions of years of technological advancement behind them, we can assume they can trigger another. The other part is creating somewhere to hide. I suspect that a wormhole into the newborn universe could suffice, if one end was sufficiently pinched off until the new universe had cooled to survivable levels. The throat of the wormhole could be a hiding place. This theory also explains the fine-tuning needed for life – the Universe self-replicates, with the help of intelligent life, and thus is subject to Darwinian selection. Discovering this could be an interesting plot point. [Answer] I a trillion years the tech for the following will be available. Breaking apart other planets and converting their mass into hydrogen and helium. Using the hydrogen and helium: Option ``` 1. Start a new sun 2. Re-kindle the dying one. ``` ]
[Question] [ We’re all familiar with the heroes that can’t die. Honey-badger (with the claws and the angry voice), Dreadpeel, that girl with the weird cheerleading obsession... Basically they all have the same superpower: any one of their cells contains the blueprint and exact reconstruction details for their entire undamaged body and can, with relative ease, repair any and all damage. If even one cell remains alive it can regenerate their full body plan, including memories and brain patterns. But somehow, despite the fact that these heroes regularly bleed everywhere or lose limbs that then regrow; the cells that have separated from the ‘hero’ never grow back into a full being. You would expect a dismembered arm to grow back a torso as well as the torso regrowing an arm, and then before you know it you’re neck deep in spandex clad immortals. The question, then, is how a biological entity capable of ‘healing’ at such an incredible rate can ensure that only one copy of itself remains. The fewer secondary superpowers (like every cell having ESP) required the better. [Answer] [Quorum sensing](https://en.wikipedia.org/wiki/Quorum_sensing) would be a very effective mechanism. This is a real life biological mechanism which is used by many small creatures like bacteria. Basically, it's a way of detecting how many similar entities are out there, and changing behavior when there's enough. Yeast is one such exemplar. It usually reproduces asexually, which is very effective in unforgiving environments. However, we know that sexual reproduction is better for the health of the group as a whole. Yeast knows it too. If it lands in a nice environment (such as a bucket of grain-water that I want to turn into beer), it will procreate asexually until it senses that there's a lot of yeast around. At that point it transitions to reproducing sexually, taking advantage of the great nutritious environment. (It also changes metabolisms, which changes what it leaves behind after metabolizing the sugars. Brewers prefer the flavor of the latter phase, so we make sure to put enough yeast in to ensure it rapidly enters this desirable phase). This mechanism is also used by bacteria that form biofilms. A thin biofilm is a disadvantage because you spend a lot of energy excreting chemicals that prevent you from moving, but you don't gain benefits until it's thick enough to start protecting you. Bacteria that form these films typically quorum sense to tell all of them "We have enough cells. This is the time to start acting like a biofilm." If the cells in your superhero used a similar policy, they would cease to reproduce once they left the body because they could not sense quorum. This also has the neat effect of possibly preventing the superpower from turning on when the kid was born. It might not be until puberty that he has a quorum to turn on this superpower. Books where teens get superpowers are good money right now =D Also potentially interesting might be algorithms like [Raft](https://raft.github.io/). Raft is an algorithm to automatically generate these structures. Cells could use an algorithm like Raft to elect a lead cell, which can speak for the entire body. This would probably be a cell in the brain, because of its nice neural connections. If that cell dies or stops talking (and it might eventually die for some reason), the other cells can use the algorithm to elect a new leader. If your superhero had such an algorithm, a hacked off limb would immediately notice that there was no lead cell. It's cells would enter an election phase to elect a new leader. Upon electing one, it would do a roll call, see that there is not enough of a quorum to act like a superhero, and the limb would act like... well... a hacked off limb. [Answer] ### There is exactly one important cell - the *Core* The *Core* is what coordinates the super-healing. Every other cell is unimportant and will simply die when cut off from a "normal" body. They can't really regenerate on the super-natural basis that you assume, it just looks to the observer as if they would. Basically when you see a torso regenerating into a somewhat normal-looking human you know that the torso currently contains the *Core* and this *Core* is initiating the *Restore-Humanoid-Body-Protocol*. This special cell is also able to move around and assume a different function in the body. This way it's not so easy for the super-villains to pinpoint which cell is the important one by killing the hero over and over again, always keeping an eye on which part is the one that regenerates. The cell can also not be copied because *magic*, which is why there is always only exactly one. This also means that if you manage to destroy this one specific cell the super-hero will really die. [Answer] Healing is partially or totally spiritual. Each hero has billions of cells, but just one soul. Only the body portion with the soul can regenerate. If the body is torn into multiple small pieces, the disembodied soul randomly picks a suitable part and kickstarts it into life. All other body parts, without connection to the soul, wither and die. If you don't like the word or concept of soul, substitute ki, ka, soma, mana, cosmos, prana, moxie or whatever other mystical energy type you like best. [Answer] > > The fewer secondary superpowers (like every cell having ESP) required the better. > > > Each cells can regrow the entire body, but cannot create organic matter from a void. Therefore it needs to have a blood supply, since blood is how building blocks are carried to all the cells in the organism. So, when Miss WipeMeNot got a chopped arm, both the arm and the body will start regrowing: the arm will quickly finish all its energy storage, starving, while the body will have a constant supply of nutrients, and will be able to regrow the missing arm. An interesting experiment would be to observe what would happen when pulling out the heart from the body, but that something nobody achieved, yet. [Answer] A never really covered idea about these regenerative beings is that they create matter out of nothing. They don't draw stuff from the ground or air as that would mean they draw from kilometers around or they would metabolize their hacked off pieces and nearby people, enemy villain who did the hacking included. So lets assume theres a kind of dark energy/matter that floats around the universe not interacting with anything except people who have a connection and use it for their various superpowers. This means that the moment the super healer gets chopped, the dark matter that powers him makes a "choice", this could either be a choice of majority (which piece contains the most mass, that's the one that remains powered) or a choice of majority connection. For example a connection could be the nervous system as most superpowers can be controlled, so upon a beheading the head would regrow a body rather than the body a head. If blown to smithereens the dark matter "sees" each piece break off and chooses the largest piece of brain matter until only individual cells exist. Possibly the dark matter can still choose cells that broke off in case the individual clumps it chose first get ripped to atoms anyway. [Answer] ## The cells do the math before they are fully severed Each cell in the nervous system generates a weak signal that adds with its neighboring nerve cells forming a **regenerate signal**. The regenerate signal is strongest in the core of the body along the spinal cord and generally gets weaker as it goes through out the body with the obvious exception of the head where it is pretty strong there too. Cells in the body can measure the regenerate signal to determine how far away from the core part of the body they are. Upon taking damage the pain signal gets sent out to the entire body much like the regenerate signal. Cells on either side of the injury compare the pain signal to the regenerate signal to determine if they are on the core side of the injury or the outer part of the injury. If they are on the core side the pain signal will trigger them to start regenerating. If they are on the outer part of the injury they do not regenerate until the damage between them and the core side is regenerated. Cells that lose contact with the body like from blood splatters do not get the pain signal, and thus do not calculate if they need to regenerate. Any part of the body that has been severed will stop getting and producing a regenerate signal and as such will lose the ability to regenerate. For example: if the right arm is cut off, it will not regenerate even if the body is later vaporized. This solution relies on that damage is not instantaneous or extreme. With enough destructive power one can overcome the regenerative ability and kill them. The nervous system can send signals at [286 mph](http://discovermagazine.com/2011/mar/10-numbers-the-nervous-system) (you can up this for a super if you want). So if a speedster or weapon can launch an attack that is moving faster than 286 mph and it propagates out uniformly destroying all neighboring cells and never drops below the 286 mph then no part of the body gets the pain signal and thus do not know that they need to begin regeneration. **One last Warning**: Note that if the regenerate signal was ever reverse engineered a person could mess with the regenerate signal in the person to cause odd effects to occur like budding, or completely jam it to make all cells think they are part of the damage and thus should not regenerate. [Answer] **Cells are semi-psychic** Each cell emits a small psychic aura, which is strengthened by the cells around it. This aura operates outside the realm of physics (On another plane of existence, perhaps?), and all cells can 'detect' the aura at any range, instantaneously. The aura can't transmit information - It's just a "Yep, it exists" signal. The strength of the aura determines which part begins regenerating. If the cells sense an aura that is stronger than their own - That is, it's attached to a cluster of cells larger than theirs - They don't regenerate. If theirs is the largest, they will begin regenerating. As cell division is not an exact process or punctually timed process, even if you manage to split the cell count and aura strength exactly in half, you'll only end up with one full body. Both would start to regenerate, but one would end up outpacing the other - At which point, the larger one would continue and the other one would not. This allows for any one cell to regrow the entire body (If all other cells are destroyed), and also ensures no budding. On the other hand, it doesn't take into account things like memories, providing the actual resources for regenerating, etc. But that's largely hand-waved anyway. [Answer] # Super healing is controlled by the brain Normal cell healing is mostly autonomous. The brain does not tell cells how to heal cuts, etc. However, this makes it difficult for sophisticated healing mechanism to occur. Few creatures can regrow limbs, and even then, usually only certain body parts. Super healing requires more intelligent processes -- recognition of the nature of the wound, routing of nutrients and coordination of cells, etc. A certain structure in the brain forms to orchestrate this, near to the structures which control heart rate, breathing, and other subconscious processes. As such, whichever part of the body has nerve connections to that part of the brain will heal. [Answer] ## Quantum Entanglement You aksed for biology but I will answer you with physics. If you want a theory that could justify the link between your cells, just take a look at Quantum Entanglement. Let’s say each Honey-badger’s cell contains one subatomic particle for each possible cells pair involving it. How do particles get entangled and spread into all his cells at the beginning? I don’t know and I think Honey-badger don’t know either! But one thing for sure, if anything happens to one of these particles, the entangle one will instantly get the information about it. And what is real cool with this is that it's a real “instantly” here, the speed information transfer has no limit in theory. So you don’t have to care about Dreadpeel being cut in half and scattered onto different planets, the information will pass instantly! Of course, this is an interpretation of Quantum Entanglement, and I ‘m sure an expert will say it’s non-sense… But take a look at the theory and I’m sure you will agree that what it can or cannot do is not "crystal clear"... **EDIT** : See, I knew somebody would be able to demolish this answer but I didn’t think this would be OP himself! ^^ [Answer] # First law of thermodynamics says NO! > > The question, then, is how a biological entity capable of ‘healing’ at such an incredible rate can ensure that only one copy of itself remains. > > > The other thing to consider here is what is powering the healing. The first law of thermodynamics is that the total energy of an isolated system is constant. i.e. you can't magick out energy to heal, you're consuming it from somewhere. Consider an approach where: * the body consumes "itself" to generate energy to heal * the less energy the body has available, the less quickly it can heal * if there's no "available" energy left, the body *can't* heal. * superheroes who are stronger, faster, denser, etc, are able to produce their superhuman feats because they HAVE more energy in their cells. So. Cut off a limb, and: * the limb "attempts" to heal, but then runs into the fact that it is attempting to regrow an entire body from the power than a limb holds... Nup, not even energy to create an entire body. * the body attempts to regrow the limb, and can successfully pull a portion of energy from all of the remaining limbs to grow the missing one. This has the side effect of weakening the superhero. They need to eat more afterwards to recoup their strength! This is also an approach taken by several series I've read, one that comes to mind is Larry Correria's [Monster Hunter International](https://www.baen.com/monster-hunter-international.html), where the only way to kill a werewolf without using silver, is to traumatise its body so much that its superhealing can no longer keep up with healing the damage. In the scenario where a body is cleft in even halves...? Urm... The superhero pulls their two halves together, and the two halves re-grow together? Actually, a scenario where a superhero with accelerated healing that is split in half, kept separately, and then kept alive, and thus regrows into two separate versions would be a fun book I'd like to read! [Answer] # Time Paradox Sure, each cell that survived could have formed a full new superhero. But there's a small chance that it didn't. All possible nows where multiple cells generated a body are inherently unstable and we just live in the one reality where only one new superhero was grown. [Answer] # Cells function as a collective The cells function as a collective mechanism. Even when separated they are connected until cell death. The regeneration is controlled by the collective; Wherever the largest mass of cells create the greatest collective signal, that will be the source of regeneration. It is only if there is only one cell alive and it senses that is not connected to any other, that the single cell will begin to regenerate. This might just be ESP... [Answer] # The brain makes backups of itself over radio waves The body can rebuild itself perfectly from a basic DNA plan. But if the brain is destroyed, how can it be rebuilt with all the hero's memories? To achieve this, the brain is constantly sending radio streams that are received by all cells in the body which transcode the information into DNA that can later be used to rebuild a brain. If an arm gets cut off, it will still receive these radio signals, indicating that the original hero is still alive nearby. So it does not attempt to grow into a new copy of the superhero. After some time it starts to decompose. Meanwhile the brain releases the right hormones to grow a new arm. On the other hand, if the brain is destroyed, say by a ray gun or giant hammer, the radio transmission stops. All cells that remain alive assume that a new brain needs to be formed. If multiple separate body parts exist, the first one that grows a brain will start sending radio waves and the others will cease their regrowth efforts. This creates some really interesting edge cases like when the hero loses a body part and then they are rapidly separated - or one of them is moved into a Faraday cage. [Answer] Depending on how you want your healing to behave I submit a system like this, Whenever part of the hero is severed (eg an arm is cut off) the severed portion will quickly mutate cells to emit "I'm here" spores and mutate more cells as receivers. The mostly intact super hero's main body will quickly mutate or already have small numbers of cells that will emit "still alive" spores. If a severed limb detects any "still alive" spores it will immediately cease healing. If a limb only detects "I'm here" spores it will decode the "I'm here" spores for information on the other nearby body parts and if it thinks those parts are better suited to regrowth (more brain matter, higher mass, more reserves, etc) it will cease to regenerate. One fun thing you could do with this system is that all inactive body parts could attempt to seek out the one that is growing, making tiny hairs to inch closer to the regenerating part of the super hero. This could also be used as a plot hook where the villain figures out he can guess which body part will grow the new Super from the spores. Or the villain saves "still alive" spores from a previous fight and before the fight starts sprays them on the super hero effectively making them mortal. [Answer] **Hormones** Many biological systems use signalling chemicals to inhibit the growth of other cells. The largest functional chunk of the Heros body emits hormones that other remote cells can pick up which inhibits their growth factor. Only one hero can exist in an area at a time. Although a determined attacker could obtain a sample before it was inhibited, remote it to a remote location, and grow a new copy. [Answer] **Each cell is a holographic quantum entangled computer of the whole person.** The super hero in question is actually a collection of organic cellular quantum computation masses. A typical person has about 37 trillion cells, and 7E27 atoms, making each cell capable of having an entangled particle with every other cell in the body simultaneously. (source: google) By allowing each cell to communicate and compute the state of the whole person, any damage to the person can be undone by allowing the portion of each cell that is a quantum computer to collapse the wavefunction so that it's entangled pairs are moved to their original state before the damage occured. The network of linked particles ensures the whole person can be restored from ambient energy sources allowing the motion of the particles into their undamaged positions. Since each cell can signal every other cell, the cells can assume a policy of restoration to the largest available undamaged portion of the whole. If two are exactly equal, a random tiebreaker can occur to decide which section to restore from. If any amount if the entangled network is completely unavailable, new tissue is grown and new particles entangled. Any additional mass can be acquired from the surrounding environment, or reused from damaged tissue that is available. This would impose several limits on regeneration though: In a near energy-less or mass-less environment regeneration cannot occur, so deep space would probably take a long time to regenerate from the stray photons and interstellar particles. If every single cell is destroyed, and thus all quantum computers capable of collapsing the wavefunction of surrounding matter are destroyed, the person dies. If the person is violently blown apart at over 50% light speed, the particles travelling in opposite directions redshift out of each other's universes and can no longer communicate, this could lead to duplicates in this scenario, but I think is hard enough to accomplish that we can consider it impossible in normal circumstances. The amount of mass needed in each cell to link to every other cell is noticeable. chopped off limbs would lose close to 1% of it's mass as entangled particles are drawn away and back to the regenerating body. [Answer] **Asymmetric stem cells** There's a tree-like branching structure of super stem cells throughout the hero's body, similar in shape to other branching structures in the body such as the nervous system and the blood vessels. These super stem cells don't divide randomly, they bud from one end. Each super stem cell is only able to regrow new super stem cells further along this structure from itself, and regrow ordinary flesh around itself. The ordered, structured nature of the super stem cell network is an essential part of how it knows not to grow eyeballs where there should be fingers or vice versa. Because of this, an arm can grow a new hand but a hand can't grow a new arm. One consequence of this is that if you dug into the hero's organs with an ice cream scoop and took a piece that had the root of their super stem cell network in it, then your scoop of deli meat would grow a new hero and the original hero's skin would super-heal shut but they would be left with an internal wound that has no enhanced healing powers. Another is that it may be possible to conduct permanent plastic surgery on the hero, assuming you can cut them faster than they heal, by keeping the threads of super stem cells intact but moving them around relative to each other. [Answer] **Extra-Dimensional Power Source** This healing violates conservation of mass and energy, blatantly, as none of these heroes consume anywhere near enough food to heal the way they do. So, the energy has to come from somewhere, right? So part of how their power functions is to reach out to wherever this energy is stored, and siphon it off to fuel the healing process. We can visualize the source of power as like a bubble of energy floating in some extra dimensional space somewhere. The hero has some sort of inverse charge or similar phenomenon that is attractive to this energy. There is a bit of tension preventing this energy from crossing the border into our world, but when this tension is overcome, it forms a singular conduit to whatever is 'pulling' on it the hardest. So, the larger/most conscious section of tissue wins the tug of war, bridges the gap, and pulls the energy into itself to fuel the healing. If no pieces of tissue are conscious or particularly large, than it's just which ever one coincidentally happens to bridge the gap first. Narratively, this works well, as it doesn't really matter which of our hero's disassociated organs and/or limbs manages to start re-growing itself, and if it does, the 'magnetism' effect provides a mechanism for selection that can be worked in more or less arbitrarily without running the risk of violating the rules of your universe. [Answer] # Soul binding Simply put, the hero's soul is always able to detect the smallest particles of his/her being. When a complete molecular disintegration occurs (equally distributed), the soul oversees the remaining atoms and energizes them into forming previous (or new) physical structures, choosing from the groups of atoms that better combine with each other in order to rebuild the molecules for the body's cells. The choice on how this regrown process is done is entirely up to the soul (this would technically allow to have slight or huge variations in the newly regrown physical being). ]
[Question] [ I want the Netherlands to be flooded entirely, and **I want the event to be of such a scale that it goes faster than hydroengineering can keep up with.** This will mean that I need a sea level rise of about 330 meters, since the highest point in the Netherlands is the [Vaalserberg](https://en.wikipedia.org/wiki/Vaalserberg) at 322.4 meters above NAP and I want it flooded too. [Wikipedia](https://en.wikipedia.org/wiki/Flood_control_in_the_Netherlands#Current_situation_and_future) seems to suggest that apparently, a sea level rise of 65-130 cm by the year 2100 can be survived (with relative ease). Waiting for nature is a slow business though, [at 2-3 mm a year](http://www.deltawerken.com/sea-level-rise/114.html). At that rate, engineering is very likely to be able to keep up with rising sea levels, and I'll never succeed in flooding the country. Also, if I melt all the ice, on mountains and the poles, I sadly only have enough water for a sea level rise of about [216 feet/ 66 meters](https://www.nationalgeographic.com/magazine/2013/09/rising-seas-ice-melt-new-shoreline-maps/). I don't mind melting all that ice, but after that, I am about 260 meters of sea level rise short of entirely flooding the Netherlands, and I'm not sure if I can even get that amount of water. **Can I permanently and entirely flood the Netherlands, and if yes, how do I do it in as fast a way as possible?** [Answer] # Can't realistically be done. As you pointed out, **there is not enough water on the Earth**. You could get away with a [Grote Mandrenke](https://en.wikipedia.org/wiki/Saint_Marcellus%27_flood), but no more (and you want "permanent"). Adding that much water through a **"cosmic snowball"** would require a more-than-Chicxulub-sized water asteroid: the kinetic impact alone would wreck the Earth. Actually the surface of the Earth is 510 million square kilometers, of which about 80% is water to be raised. Multiplying that for a height of 300 meters gives around **30 million cubic kilometers** of water, which, as a sphere, would have a radius of around 310 kilometers: **forty times** the size of the [Chicxulub impactor](https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_extinction_event), it would not be an asteroid but a small moon, the same size and one fourth the mass of [Vesta](https://en.wikipedia.org/wiki/4_Vesta). In this picture, the Chicxulub impactor is approximately the size of the dot on the "i" of "Chicxulub" (15 km diameter). [![enter image description here](https://i.stack.imgur.com/rrAff.png)](https://i.stack.imgur.com/rrAff.png) Also, even if fragmented in an implausible string of smaller water comets, that quantity of water would get most coastal areas flooded everywhere on the whole planet and its kinetic energy would still wreck the weather systems (there's something of the kind in J. G. Ballard's *The Wind From Nowhere*). Plus, it would be *fresh* water. The alteration in salinity would wreck the oceanic circulation even more, and kill off a large(?) part of the sea life. A kilogram of ice at orbital speeds of 20 km/s and initial temperature of 10 K possesses a kinetic energy of 200 MJ. It takes 1.1 MJ to bring it to 0 ¬∞C and 0.334 MJ to melt it, leaving a net credit of 198 MJ, or 830000 kilocalories; enough to bring eight tonnes of water to the boiling point. What would actually happen is that the "snowballs" would explode in incandescent water vapour in the atmosphere. Enough snowballs to raise the sea level by 250+ meters would be enough to steam cook the planet, long before the steam condensed enough to contribute to the water level. Tectonically, Netherlands is safe again. The whole area is quiet and in the middle of the European plate. No chance of a mess like Juan de Fuca. The kind of energy needed for such a bit of planetary reshaping is out of reach of our [K0.73](https://en.wikipedia.org/wiki/Kardashev_scale) civilization and, again, would probably wreck the planet in the bargain. # The Wall Walling in the Netherlands and pumping water in requires some pumping. It turns out that with about [four megawatt of power](https://gizmodo.com/5800072/the-worlds-largest-water-pump-moves-15-olympic-sized-swimming-pools-every-minute) you can raise six hundred cubic meters of water per second, one meter. Using [OnoSendai's](https://worldbuilding.stackexchange.com/a/115699/6933) figure of 1.3E+16 cubic meters of water, to be raised on average 150 m, we get 0.3E+16 pump-seconds; given that one year is 3E+7 seconds, it's 100 million pump-years. If we want to flood Netherlands in ten years, we require 10 million such pumps, with an expenditure of some 500 *trillion* USD, and an energy requirement of 40 TW. In one year that's 24\*365\*40 = 350400 terawatt-hour. Given that "*The total electricity consumption of the Netherlands in 2013 was 119 terawatt-hour*" (from Wikipedia), this works out to about *three thousand times* the total electricity budget for the whole Netherlands. So, as long as the [science-based](/questions/tagged/science-based "show questions tagged 'science-based'") tag holds, I believe there's no way. --- Relaxing a bit (a *large* bit) the limits, the best way to go seems to be the tectonic anomaly. Instead of increasing the oceanic level, you sink the Netherlands enough that it goes under. You could get away with several years of *unexplainable geomagnetic readings* possibly linked with the planetary decrease in field strength, and nothing apparently happening. What actually happens is that the geometry of the convection zones beneath Europe is changing; a "bubble" of lighter material rises towards the surface, and maybe has risen for hundreds of thousands of years (this is the same [mechanism that had been proposed to explain certain ship disappearances](https://www.newscientist.com/article/dn1350-bubbling-seas-can-sink-ships/). It has since been at least partially rejected). Finally it reaches the underside of the European plate, which starts *flexing* between the [Baltic Shield](https://en.wikipedia.org/wiki/Baltic_Shield) and the Rhine. [![enter image description here](https://i.stack.imgur.com/NOSje.png)](https://i.stack.imgur.com/NOSje.png) Instantly, in geological terms; a matter of months, years at most, in human terms. The whole of the Netherlands, part of Western Germany, and most of Belgium subside, while the dams collapse one after another. [Answer] Have you considered lowering the highest points in The Netherlands, perhaps with explosives? That way we can reduce our target value. Additionally, is it feasible to introduce additional water from an outside source? A water-rich comet striking the ice cap would go a long way in both adding water and melting what we have, and doing it fast. I'm apparently bad at research but I imagine that if we could somehow condense all of the water in the atmosphere, we'd get at least a few dozen meters of sea level rise, as well. We ARE okay with annihilating life on the planet, too, right? Just thought I'd ask. ;-) Edit: Additionally, remember all of that cool hydroengineering that's being used to protect The Netherlands from the sea level rising? Delta Works and everything? Well, we could perhaps also do some hydroengineering to build something IN the ocean that will hold the water up against the land, and from there we can pump water into this relatively closed system from the rest of the ocean. The hard part would be building this in a way that the other, more benign hydroengineers wouldn't notice until it's too late, but it should be do-able. [Answer] As a Dutchman living 20 meters above the sea level, I will be happy to see you fail. I have full confidence in Dutch engineers, if given enough money. NL is under more threat from flooding by rivers than by the sea, you could focus on river dykes. Let's not forget that in pre-historic times all of NL already has been under the sea. The marl that is dug out from under the St. Pietersberg in Maastricht has been deposited there by sea life, and the Mosasaurus was a sea creature too. You just need to trigger some major geological event. Consider that the Alps only formed after the dinosaurs were gone, and how high they are. Finally, if you flatten the entire surface of the earth then obviously all of earth will be under water, under 2.7 km of it ! <https://earthscience.stackexchange.com/questions/7446/if-the-earth-were-a-smooth-spheroid-how-deep-would-the-ocean-be> . You could make a movie "Waterworld" about that. Oh wait... [Answer] ## Make a wall around it, and fill it to the brim. No need to flood all the other gorgeous places just to get rid of pesky Netherlands - just a big, beautiful wall. (If you can somehow make them pay for it, even better.) Just get into talks with Germany and Belgium to take care of the land part of the wall, and a few (ok, quite a few) ships to help build the shoreline portion. Make it as tall as necessary to cover the Vaalserberg. Then start pumping sea water. Now, the total area of the Netherlands is 41,543 km2 [according to wikipedia](https://en.wikipedia.org/wiki/Netherlands). We need a wall 322 meters high, so that gives us 1.338√ó1016 cubic meters of space. For comparison, the total water in Earth's oceans, seas, and bays is 1.332√ó1018 cubic meters according to Wolfram Alpha. So that means that we need ~1.005% of all that available water to fill up that giant bowl and make a slightly salty Dutch Soup. [Answer] Melting all the land bound ice on earth gets you just short of 70m of sea-level rise, total (maybe 75 if you factor in thermal expansion of the upper ocean because of a warmer atmosphere), for 330m you'll need to add water, a series of comet impacts in Antarctica and Greenland will free up large quantities of existing frozen water and add more water to the planetary system simultaneously. Alternatively hit the Netherlands with a large snowball from space and have the crater where the country used to be flooded afterward. [Answer] # Don't reinvent the wheel, use solid water, plagiarise Antarctica! The idea is really simple. Most comments suggest putting so much liquid water over the Netherlands that it stays there. The problem, of course, is that the water flows from the Limburian Hills to the lower parts. A simple work around is to copy Antarctica (see picture below), which is covered in ice, not water. When you think about it though, ice is just frozen water. Just because it's frozen doesn't mean it cannot be a flood, Wikipedia calls it an [**ice jam**](https://en.wikipedia.org/wiki/Ice_jam). Now, I hear you thinking, the ice would just melt, and the water would flow to the sea. That's right, but we can work around that: create a lot of shade, possibly by creating a reflective layer in the atmosphere so the sun's rays are reflected away from the earth (not sure if this would work properly or if it would kill most of us due to extreme cold and inability to grow things needing sun light). Weirdly enough I didn't find a question about a human-made ice age on this website. If it gets cold enough, we'd have to hope for rain and snow or just water the earth ourselves. Eventually this would turn in to ice (either under pressure caused by its own weight or the Dutch help in proving that it can be done^^). Antacrctica shows it can be done, look at those hill tops, it all covered in solid water :). Note that this seems to be a computer generated image. Image taken from Wikipedia, originally from [NASA's Goddard Space Flight Center Scientific Visualization Studio](https://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=4060). [![enter image description here](https://i.stack.imgur.com/bDBPY.jpg)](https://i.stack.imgur.com/bDBPY.jpg) [Answer] What you *really* want is Netherlands to be underwater as opposed to being above water. You really don't need to raise water levels in the entire world, you can just lower Netherlands a good 300+ meters and you're done! Solution: **an underwater landslide!** Just slide all that land under Netherlands into the ocean! You might have to take England and a good part of Europe with it while you're at it, because the North Sea isn't deep enough for a 300 meter dive. Although, all you want is to make Netherlands sink into water. So, during the landslide, the highest point in Netherlands can now become much shorter due to the land under it breaking apart. This would mean that the North Sea might even be enough to do the job. As this will be a gigantic landslide, the result would be an immense tsunami, you can wash away anything living near Netherlands in the process, if you so desire. [Answer] [Yes, you would just need to simply slow the rotation of the earth (just not sure how).](https://www.popsci.com/science/article/2010-07/what-would-earth-look-if-it-stopped-spinning) The earth's [equatorial radius](https://en.wikipedia.org/wiki/Earth_radius#Equatorial_radius) is 6,378.1370 km while the [polar radius](https://en.wikipedia.org/wiki/Earth_radius#Polar_radius) is 6,356.7523 km, a difference of 21.3847 km just based on the earth's rotation! The Netherlands lies at latitudes ranging from [50.77083¬∞-53.35917¬∞](http://latitudelongitude.org/nl/), and using the [location-dependent radii](https://en.wikipedia.org/wiki/Earth_radius#Location-dependent_radii) calculation for a point on a spheroid, I can [calculate](https://www.fxsolver.com/solve/) that sea level at The Netherlands is currently about 6364.4-6365.3 km from the center of the earth. Now if we assume that the [volumetric radius](https://en.wikipedia.org/wiki/Earth_radius#Volumetric_radius) of 6,371.0008 km would be earth's radius to the center everywhere if it were to completely stop rotating, well then that'd put the shores of The Netherlands under 6 km of water. Being that's a bit excessive, stopping the earth's rotation shouldn't be necessary. Simply extending the length of day to ~36-48 hours should be sufficient, but YMMV. [Answer] [Limburg becomes independent](https://www.nrc.nl/nieuws/2006/08/26/limburg-moet-een-land-worden-11183288-a190189) or joins Belgium, as some have proposed. A newly militarised Germany conquers Gelderland and Overijssel. The Plattd√º√ºtsch dialect they traditionally speak there is almost German anyway. Now the highest point of the remaining Netherlands is [only 69 meter](https://nl.wikipedia.org/wiki/Amerongse_Berg) above current sea level. You can make it a little lower with erosion. It may or may not be submerged if all the ice melts, perhaps one tiny island will remain, but at high tides and in storms it will be submerged, so habitable it will be not. Really, you can only flood the entire Netherlands by redrawing the borders. [Answer] [![Fault lines](https://i.stack.imgur.com/zsfqi.png)](https://i.stack.imgur.com/zsfqi.png) <https://phys.org/news/2012-11-movement-fault-lines-netherlands-due.html> I don't know all the details, but here's a best guess. There are clearly fault lines in the Netherlands, and one researcher claims its due to ground water. Also it has lots of rivers and water ways. So you need an earthquake of extreme proportions to break the Netherlands off and sink it in the ocean. So you need to augment a regular earthquake with a major shift in the underground water. Once an earthquake starts it would only takes minutes to tear the earth apart in that region. The research further could not measure the crust exactly so there could still be hidden plate lines. He had to use a secondary technique documented in his PHD research paper. So you will have to flood the earth, and crash the netherlands into the ocean/north sea. However, it turns out the north sea isn't super deep. If you can wash it out as far as Faroe Island the ocean floor is 1000m deep in some areas and would be permanent. [![ocean map](https://i.stack.imgur.com/VMlCU.png)](https://i.stack.imgur.com/VMlCU.png) You might be able to find a suitable area closer, but I don't have the time to search every square inch to find a deep spot. Also you only need 1 spot deep enough to hold the mountains, the rest could be shallower. Also if the netherlands start breaking off along the mountains, the mountains might just fall over into the hole, vastly reducing the total height needed. Your best bet is a giant underground sink hole formed by eroding water. The majority of the Netherlands falls, and is now on the ocean floor. You could however, make your sink hole as deep as you want to fit the story. Also the mountain range could simple collapse with such an event and now you don't need 300m. [Answer] **Yes and less than an hour with a meteorite impact**. The Netherlands have a distance North-South of 300 km and West-East 180 km. So to bury it completely you need something like the [Chicxulub meteorite](https://en.wikipedia.org/wiki/Chicxulub_crater) which killed the dinosaurs. It's just a rock with 10 km diameter hitting with cosmic speed. When it hits the Earth, the ejected material will create a hole of several kilometers (!) depth. Apart from the fact that it will destroy just about anything in its vicinity (Germany, France) the North Sea connected to the Atlantic will rush in and fill the round hole formerly called Netherlands. I am sure we can optimize the process by hitting only the highest part of Netherlands and let the dam breaking do the rest. [Answer] Think bigger: There's not enough water if you melt all the ice, so you need to displace water from the low parts of the oceans to raise the sealevel further. Start drilling large-diameter holes in the ocean floor and/or through islands or along the edge of continents until the magma in the Earth's mantle starts pouring out. This will raise the surface temperature of the planet and melt the various glaciers and the lava flowing into the ocean will displace water, raising the sea level further. This will be expensive, but the melting point of tungsten is higher than the melting point of igneous rock, so you should be able to build the necessary equipment and perhaps even pipe the lava to the optimal location given a large enough budget. Bonus points for offsetting the massive electricity bill from the drills with geothermal power plants. Even more bonus points for setting up a sufficient quantity of drills to be able to flood the Netherlands in a matter of hours. Extra, extra bonus points for creative use of weaponized lava against everyone who's undoubtedly going to be trying to stop you. Also: Why stop with the Netherlands? Muahahahaha! [Answer] Massive meltdown of the poles' ice will put an end to the Gulf Stream. While the Netherlands will be busy trying to contain the sea's unstoppable rise, the weather in the northern hemisphere will turn toward a permanent ice age. Netherlands will be covered in a thick sheet of ice for a long, long time. [Answer] Comets are outside of your control (in short time spans). What you can control though are rockets and explosives. You need to bring 2 rockets into earth orbit. One carries a [Tsunami bomb](https://en.wikipedia.org/wiki/Tsunami_bomb) and the other enough TNT to destroy the Vaalserberg. Follow this link to [calculate the amount of TNT](https://worldbuilding.stackexchange.com/questions/8942/how-much-tnt-do-you-need-to-blow-up-mount-everest). Also, you want the heat shield to be able to protect the payload until earth surface impact. Re-entry of both rockets should be carefully planned as you want the hill to be destroyed before the flood arrives. You might also need more than just one tsunami bomb carrying rocket. The tsunami will destroy all sea defense in the Netherlands, flooding The Netherlands completely for a short period of time and partly flooded for a very good period of time (until the dikes are fixed and land is reclaimed). So, it's not permanently entirely, but this is achievable. If you're on a tight budget, you may be able to reduce costs by launching additional TNT carrying rockets addressing some of the [other hills](https://nl.m.wikipedia.org/wiki/Lijst_van_heuvels_in_Nederland) and reducing the explosive power of the tsunami bomb(s). [![enter image description here](https://i.stack.imgur.com/u64Z9.png)](https://i.stack.imgur.com/u64Z9.png) image source: <https://en.wikipedia.org/wiki/Flood_control_in_the_Netherlands> [Answer] ## You Probably only Need a Meter or Two According to Wikipedia, about 50% of the land mass of the Netherlands is within 1 meter of mean sea level. So if you were to suddenly raise the sea level by a little more than that, say about 2 meters, you'd have submerged the majority of the country. The remaining bits are going to be islands or the new coastline of Northern Europe. In either case, the introduction salt water and tidal action are going to erode significant amounts of this land away. The salt water will kill off a lot of the plants, and without the root system the land will wash away into the sea. Particularly elevated positions, like Vaalserberg will just take more time. You'd need to ensure that you breached the initial layer of defenses, though, so to put a hole in the proverbial (literal?) dike, you could sabotage Maeslantkering. Particularly if there was a storm surge, failure of this system would cause significant flooding, and damage the flood defenses from the inside. So probably the formula is: * Melt off enough glacial ice to raise sea level by ~2 meters as quickly as possible. * Break Maeslantkering. * Wait. [Answer] The Earth's mantle contains a vast amount of water, [probably of the same order as in all of the Earth's oceans](https://phys.org/news/2017-06-mid-mantle-earth-oceans.html). Since the average depth of the oceans is about 3.7 km, there is plenty of room to increase global sea-levels by 330 meters, if we can bring part of this water in the mantle to the Earth's surface. [Answer] Step 1: Figure out how far you want this land mass to drop. (Yes. Going down.) Step 2: honeycomb some amount of the ground with automated mining machines that place explosives as they go on the left-behind support structures that are holding everything up. Step 3: Arrange a point to let the water in. Step 4: *boom*. Step 5: Let the water in. [Answer] ## Blue Goo Scenario How about a variant on on the [Grey Goo](https://en.wikipedia.org/wiki/Grey_goo) scenario! Scientists trying to create a new hydro-phobic material that automatically coats a surface slip up (pun intended) and create instead a self-replicating nano-machine that reacts with water. Instead of consuming all matter the escaped, wildly reproducing nano-machines mix with water, causing extreme changes to surface tension, leading to the water sliding up walls, hills until everything is coated in about 6 inches of water. I'll leave as an exercise to the writer justification for why the Blue Goo doesn't spread to the rest of the world. [Answer] This looks like a job for a mad scientist type super villain who plants super bombs under the high parts of the Netherlands and the Greenland and Antarctic icecaps. It would probably take hundreds of super bombs miles beneath the highland parts of the Netherlands, each vaporizing about a cubic kilometer or cubic mile of rock. The vaporized rock will escape through some openings, perhaps created by especially powerful bombs, and many people will be burned to death by the super heated vapor. The unsupported hilly parts of the Netherlands will collapse into the giant cavern created by the bombs and will now be far below sea level. Meanwhile the thousands or millions of super bombs beneath the Greenland and Antarctic ice sheets with explode, vaporizing many cubic miles of ice that will later condense and rain down, and also starting the rest of the ice sheets sliding into the oceans, raising sea levels worldwide. The Netherlands will flood permanently, which will be a terrible disaster for any citizens of the Netherlands not already killed by other effects of the bombs. Millions and more likely billions of other people will die worldwide. Or, the mad scientist super villain might want to make only the Netherlands suffer. If he can teleport a lot - I mean thousands of cubic miles at least - of matter he may be able to sink the Netherlands. He can slowly teleport matter out from under the hills and high lands of the Netherlands, so that the high regions sink about an inch per hour or something, slow enough not to kill many people, so that most will live to experience the later flooding. When the hills are down to the levels of the rest of the Netherlands, continue sinking them and also sink other regions, down to at least tens of feet or meters below sea level, and also below the level of neighboring regions in Belgium and Germany to limit the devastation to only the Netherlands. But don't sink the coastal regions yet. As the Netherlands sinks, water from its rivers will pour into it and start filling it up, and as the Netherlands sinks farther, opening the sea dykes to let out the river water will do no good, since the sea level will be higher than the level of flooding from the rivers. Then the super villain could start teleporting cubic miles of ice from Greenland or Antarctica into Lakes and rivers in the Netherlands where it will melt swiftly and add to the water levels. When the coastal regions of the Netherlands are the last parts above water, then the super villain could use one or more atomic bombs to open large sections of the sea dykes and let the ocean flood in, while teleporting rock out from under the coastal regions to sink them below sea level too. Thus the super villain may be able to sink all of the Netherlands and only the Netherlands permanently below the sea while minimizing the damage to the rest of the world and the number of non Dutch people killed. And these are the only ways I can think of to flood the Netherlands while restricting the damage to the rest of the world. Other scenarios I can think of should be result in much more devastation world wide than in my first scenario. [Answer] Given that the moon causes tides would it not be possible to use gravity to pull water towards one part of the Earth hence why not position a very large and dense "moon" in geostationary orbit. [Answer] The event you require is a significant tectonic movement of a large plate rising up from the ocean floor to displace enough water volume to raise the global sea level to the required height. The volume required is approx 1√ó10^8 km^3 divided by the area of the pacific plate 103,300,000 km^2 gives an approx rise of 1 km required Obviously this would be a "significant" event in the geological history of the planet. or you could have smaller/multiple areas rising further in combination with the Antarctica ice getting at least dumped into the ocean (no need to melt it). Note that the rising areas can go all the way to the surface creating new land masses. Very "messy" obviously what with all the global quakes and tsunami even if done relatively slowly over several years. [Answer] I've got an idea, although it won't achieve what you need by itself. It's also not really science-based. It can and probably should be used in conjunction with the other answers though. The idea is this: ***instead of only attempting to overwhelm Dutch hydroengineering, what about also taking the hydroengineering away from the Dutch?*** ## **Tides of Madness** An ancient aquatic doomsday cult has been lurking within Europe for centuries, secretly growing in strength as they bided their time. In the current era their tendrils extend across all segments of Dutch society, such that prominent politicians, generals, scientists and engineers are counted amongst their ranks. The cult's goal is to drown the Netherlands and eventually the entire world. Cue your geological/meteorological event(your hard science answer). The cult sees this as a sign from the Elder Gods or whatever deity they worship that their long wait is over; it is finally time to strike. They launch a coordinated assault on the entire infrastructure that keeps the sea out. The sea wall is demolished, automated systems are swamped with viruses, cultist-farmers in the countryside attack the dikes, and so on. The public figures among the cult members have a more specific part to play as well. The ruling coalition calls a press conference just so the Prime Minister can scream HAIL AZATHOTH! YOUR LOYAL SERVANTS AWAIT THEE! on camera. Since many/most of the top minds are also cultists, the Dutch infrastructure would turn out to have hidden weaknesses intentionally built in that now come to light in the worst way possible. The unsuspecting Dutch public can of course act on their own initiative to save themselves, but the fear and paranoia sowed by the highly placed cultists will cripple their efforts. If your burgomeesters, your aldermen and even your neighbour Tim were secretly frothing madmen all along, then who can you trust? By the time they get their act together, it will be too late. A giant tsunami or whatever kill screen you had intended finishes the job. [Answer] **Move the Moon** Deluge S.A. is enviromental friendly company and that's why our flooding solution don't relies in global warm nor ice chunks from space bombardement. Instead we use fine relocation of the Moon to provide almost instantaneous flash floods for your needs. We will provide a circular area floded anywhere on the globe and at almost any height. **Use a Black Hole** Deluge S.A. aways seeking innovation just lanched a new product in the marketing. We are lauching geo stationary satellites with a black hole generator capable of generating a BH with the same mass of the Moon ([check specs](http://xaonon.dyndns.org/hawking/)). We are now able to provide globaly multiple services at the same time. (Also we stop that lousy Astranomers complains about getting the Moon out of orbit). And don't worry those BH are not hitting the Earth grats to our exclusive handiwanium engines, we guarantee it or give your money back! [Answer] there's the Earth way and there's the apocalyptic way, how far do you want this scenario to go? if a meteor where to fall into the pacific ocean, a sufficiently big one, the resulting tsunamis would create waves hundreds of feet high, it would create a Dinosaur scale kind of event, all the ice in the world would melt and as the tsunami arrives through the poles to the Atlantic the waves would have barely slowed down, it would inundate hundreds of miles into the mainland before it recedes, but as all the ice in the world would have melted and big chunks of the ocean would have been evaporated it would create mayhem as a global rain would start for a few months, all coastal areas would be lost world wide and the sun would be blocked, after some more months (the time its depending on the size of your meteor) global temperatures would plummet and the Netherlands would be under a large ice cap as well as most of Europe making it permanently uninhabitable for a few millennia. [Answer] Heat the planet by several degrees, so that the thermal expansion of the oceans raises the surface sufficiently. Haven't done the math -- but Curt Stager did cover it thoroughly in his book Deep Future. My best recollection was that he was predicting something like an >80 ft surface level rise from melting all ice, plus ocean warming. Not 330 meters. So we need a lot more thermal expansion to get every last bit of your target under water. There is the wild card of the methane hydrates in all the permafrost, releasing geologic storehouses of methane, which is something like 25 times stronger at boosting temperature than CO2. Still, I think Stager might have proposed something like 200 ft rise from that? Not sure. Actually, I think he mostly warned that with methane hydrate meltdown, all bets are off, and the last time we had no surface ice, half of North American was covered by a shallow inland ocean. Anyway, the trick seems to me thermal change, not some wild-hair notion of pulling in water from comets, much less from (dry!) meteorites. [Answer] From easiest to hardest: 1) Build a dam across the strait of Gibraltar and the Sun will drain the Mediterranean. Takes a while though. The Black Sea and the Caspian soon follow. 2) Do the same to the Tigris, Euphrates and the Persian Gulf. 3) Dam the Bearing Strait and re-route the Arctic rivers and the Arctic Ocean will lower somewhat. 4) Also, to seriously melt the ice caps you'll need to release some GHG. Methane's great, but if you burn it you get water too! To do some serious damage you'll need to burn the Methane hydrates under water. I dunno how much water that'll be... but I'm sure it'll be a bad day in Amsterdam.  [Answer] As long as you don't mind pulverizing another continent, you can do it. Australia isn't very far above sea level, so let's consider south america. SA has an average elevation of about 2300m. The surface area of SA is 17840000 km^2. So the volume of south america above sea level is: 17,840,000km^2 \* 2.3km = 41,032,000km^3 The surface area of the earth is 510,072,000km^2. Assume for ease of calculation that the all of the land outside of south america is exactly at sea level, so that any raise in sea level will cover them completely. This isn't true, of course, but this will give us a lower bound for how much we'll raise the sea level. We pulverize all of south america above sea level and we dump the rubble into the ocean. This will raise the sea level by at least 41,032,000km^3 / 510,072,000km2 = 0.08km = 80m. You can get the upper bound by assuming that none of the other continents get flooded at all. In this case, we divide the rubble volume the area of the ocean. This gives us 41,032,000km^3 / 360,000,000 km^2 = 114m. The real rise in sea level would be somewhere between 80-114m. However, I don't think you could pulverize most of any continent without causing so much damage to the environment that flooding the netherlands (and deliberately destroying the better part of a continent) would be the least of your worries. [Answer] To achieve the sea-level increase as quickly as possible, consider removing some of the ice shelves around the Antarctic continent. Throw in some below-ground heating to lubricate things, and the whole ice cap just slides off. Firstly, this creates a *really* big tsunami. Secondly. as soon as the sliding ice starts to float, it displaces its own weight. The sea-level rise post-tsunami is quick and permanent. ]
[Question] [ **Setting:** a fantasy world with a culture loosely based on the late middle ages or early renaissance, with more value placed on the fantasy elements than strictly adhering to a proper "time period" (i.e., more World of Warcraft than Game of Thrones). **Scenario:** a group of adventurers happen upon a hidden cache that has been buried for ages. The biggest item catches their attention most. It's a nuclear bomb, but of course they'd have no way of knowing that. So they haul it to the University for study, where one of the smartest minds in the world vows to determine what it is. **The question:** how far would this person get? What would this person be able to determine about the device? I know there are different kinds of nuclear bombs, but I'm not smart enough to know which one to choose; pick the one that would be the "easiest" to crack, I suppose. As I said above, the time period is very loose. If nobody in the late middle ages or early renaissance could have figured it out, could somebody in, say, the wild west? As a last resort, what kind of aspects of these time periods would have to change to make this even remotely feasible? Thanks for your consideration. [Answer] # Let's try to do this. (They told you it can't be done. They're right. Realistically, it can't. So, disclaimer: I'm going to employ industrial quantities of high-grade Improbability). ## Notes I had to play with "realize what this thing is". There's no reasonable way I can hand-wave an alchemist deducing nuclear fission. The best I think we can aim for is *strongly suspect this thing was designed for, and capable of, flattening a city*. And I had to conflate alchemical knowledge with *sorcery* and occult lore, to help explain why someone might decide to do some things in one way or another, or why jump to some very specific conclusions instead of others. In several places, the actual likely outcome is one dead alchemist. Most parts of a nuclear bomb are toxic, and several of those that aren't all that dangerous will become so once subjected to standard alchemical procedures. During examination of the explosive lens, for example, it's a safe bet that poisoning will happen, or at the very least the alchemist will find himself changed into a [canary girl](https://en.wikipedia.org/wiki/Canary_girls). And finally, the bomb was almost surely not functional before the examination, and will get messed up beyond all recognition by the disassembly. It may still poison a large area, but no mushroom explosion, ever. --- So the High Alchemist gets his hands on this strange object, incredibly heavy. He is scientifically minded, so he starts recording *everything* on vellum. The runes on the surface of the object, its size, its weight. How the various parts are put together. After a short time the alchemist concludes, so far, that the device is built up of two parts. One is a jumble of incredibly small components connected by colored wires, and put together every which way. There are several things resembling gems and precious metals in this part of the object, and they are carefully arranged to form what looks like the most complex amulet he's ever seen. Whatever this thing was designed to do, it must do so by channeling *ridiculous* amounts of magic. He very carefully pries the boards apart and gives them to an apprentice to record every printed circuit, every trace, every wire, and every object and rune on them. Several components appear to have decayed during the time, and are clearly unrecoverable. The [second part of the object is a heavy sphere](http://nuclearweaponarchive.org/Nwfaq/Nfaq8.html#nfaq8.1.2) armored in steel. [![A replica of the Gadget device](https://i.stack.imgur.com/3YsuR.jpg)](https://i.stack.imgur.com/3YsuR.jpg) With care, the alchemist opens the shell. There are other shells inside. Whatever is inside must be really precious. The wires clearly demonstrate that *something* was intended to go from somewhere outside, along the precious copper cables, into the sphere. Magic, since the cables are not hollow. An egg? Could this thing be an Alchemical Egg? [![Alchemical Egg](https://i.stack.imgur.com/yNm3W.jpg)](https://i.stack.imgur.com/yNm3W.jpg) The alchemist goes on with bated breath and trembling hands. If this thing is really an Alchemical Egg, its weight has an obvious explanation. It has been already activated somehow, long ago, and a sizeable part of the mass has been transmuted into gold. But more than that, inside the sphere there must still be its key component - the [petra philosophorum](https://en.wikipedia.org/wiki/Philosopher%27s_stone), the Philosopher's Stone. Carefully, he removes layer after layer. After a couple days' work, he is again puzzled. [What *is* this thing](https://static01.nyt.com/packages/images/photo/2008/12/08/120908-Bomb/26028663.JPG)? The inside could contain several dangerous elements; a residue of [ignis aqua](https://en.wikipedia.org/wiki/Aqua_regia) could easily contaminate his whole laboratory, and only a fool handles carelessly a potential [alkahest](https://en.wikipedia.org/wiki/Alkahest) hazard. Spirit of mercury is also a probable component, no less lethal than the first. Then, the apprentice reported a rune structure that's totally unknown; there's a very real possibility that the thing is demonically powered. The alchemist goes even more slowly, aware that one false move and he stands to lose his life, and/or his soul. So after warding everything twice and operating inside a defensive pentacle, the alchemist removes with some effort one frankincense-smeared wedge with several pounds of [Composition B](https://en.wikipedia.org/wiki/Composition_B). Which looks *nothing* like spirit of mercury. It certainly isn't any sane ingredient an alchemist would recognize. What is it made *of*? However, the standard analysis procedure is pretty straightforward. The alchemist scoops a generous dollop of the substance and charges another apprentice with the performing of all the standard tests - acid, fire, crushing, evaporation, washing with oil of vitriol and other acids, incineration and reacting it with known substances. The following day, much wiser and one apprentice shorter, the alchemist concludes that those wedges are made of a heretofore unknown, and incredibly powerful, explosive substance. But this does not make sense at all; why armor the sphere? Why manufacture it with such care? Why connect the wedges with those wires? At this point it is obvious that the thing is not an Alchemical Egg. It is a weapon; logically, it must either be directed against something inside - it was designed to destroy the much smaller sphere in the center - or it was, more likely, designed to direct its force *outside*. On the other hand, that hellish substance the wedges are made of looks like the weapon to end all weapons all by itself, and it would have been infinitely easier to use alone. No; if someone wants to kill you, has a knife, and yet uses it to do something apparently *not* murderous instead of just stabbing you, this indicates that the knife is a *means* to cause something even more lethal to happen. Like cutting a rope and make the victim fall in a chasm, or wounding a dangerous animal to excite it to a killing frenzy. Now dreading what he's going to find, the alchemist removes the last layer. His eyes widen in shock. For a moment he thinks that his first theory was spot on: the thing *is* an Alchemical Egg, as before him there is a perfect sphere of what looks like solid gold, polished to a mirror finish. (a simulation of the un-mirrored core and partially unassembled core can be found [here](https://www.newyorker.com/tech/elements/demon-core-the-strange-death-of-louis-slotin).) Unfortunately, the substance can't be gold. It's too light by a good margin. > > This is delta-phase, gallium-alloyed plutonium, nickel-plated to prevent it from oxidizing and then gold-plated. If the alchemist could remelt it and separate the gallium, the plutonium would cool in the much denser alpha phase, which is a bit denser than gold, and proportionately more likely to [go critical with lethal results](https://it.wikipedia.org/wiki/Demon_core). Unfortunately for him, removing the gold-plated nickel layer separating the plutonium from air is not a healthy move and he would not survive the melting and its fumes, nor would his apprentices. At this point, actually, he's *already* a high cancer risk. > > > Also, the golden sphere is *warm*. Noticeably warm. And he's not so great a fool as to mar the perfection of the mirror - there're many things mirrors can be used for, and inside a sealed sphere, looking at oneself wasn't one of them. All the other uses involve magic, if not Powers that's better not to name. There's a dark spell involving the blood of a virgin and two mirrors facing one another, that can produce infinite reflections of something - like a bag of coins - and make them real and tangible. After several weeks of careful, careful testing, the alchemist comes to the conclusion that the sphere contains some powerful source of energy, likely magic in nature, that keeps the sphere warm no matter what. So: a perfect sphere, plated with gold. And finally the purpose of the assembly is clear: should all the wedges explode - which can only be triggered somehow by those mysterious copper wires, going to small devices attached to the powerful explosive - they would do so *inward*, directing an unimaginable wave of destruction against the mirror-finished sphere. A concave mirror will concentrate something; a sphere is the exact opposite, a convex mirror that will amplify and spread out the energy it receives. *In the alchemist's mind's eye, the wave of infernal fire reaches the sphere and **rebounds**, powered by the strange life force imprisoned inside, and expands again -- now multiplied a hundredfold or a thousandfold, destroying everything it encounters for miles around...* [Answer] For your reference: some years ago in Brazil a scrap thief, while salvaging through the remnants of a hospital, found a piece of material which emitted a nice glowing blue light. He was smart enough to think "wow, this will make a pretty good gift for my wife", and tried to take it with him. Long story short: 4 dead and various contaminated from a piece of Cesium 137. (Full account of the incident [here](https://en.wikipedia.org/wiki/Goi%C3%A2nia_accident)). And nowadays we have at least seen on TV that glow = radioactive. Renaissance "scientists" had no idea of atoms at all, so the best they could get would be poisoning their entire kingdom with plutonium or uranium for some thousands of years. [Answer] I admit up front, that my first reaction was to consider the comedy potential of this situation, as the device might have labels on it. That would make a big difference - think of the warnings on a bag of peanuts or a chainsaw, and enjoy imagination (*"warning: this product may destroy large cities."*, *"user safety information: this product can cause cancers."*). Leaving humour aside, more seriously, weapons designers tend to like avoiding stupid user errors from triggering nukes; maybe it would have clear descriptive labels sufficient to explained what it can do, if not how it does it. But as for your scenario, however interesting a plot it would make, the reality is that such a weapon is probably not going to do what you want, and is less useful than you thought, on so many levels. Starting with weapons design, nuclear weapons aren't just a blob of plutonium, they might have extreme precision shaped balanced charges (needed to ensure a hollow sphere fission device collapses perfectly symmetrically which is needed for fission, but which will deform or degrade after not very much time); an undamaged and somehow non-rusty very heavy steel container (to contain the initial blast for the fraction of a second needed to ensure it explodes and doesn't just fragment before significant fission); if plutonium was used it absorbs moisture from air and flakes apart, and if they used any isotope other than Pu-239 it has a relatively short half life in historical terms and will probably be effectively inert as a weapon by now (and other fissible materials may have lost enough through decay to no longer be viable); fusion devices may have materials like polystyrene which can degrade over time, and fragile precision parts calculated in ways they can't hope to intuit, and easy to damage or move even if the device is examined carefully. More seriously, all but the very simplest devices above all will have electronics or computerised control circuitry (to sequence detonation, detect correct impact, altitude, or other conditions met, authenticate the key/s used to authorise settings and activation) and are fail-safe design (designed to make it innately very hard or impossible to explode unless everything is just right) ... and therein lies a problem. Electronics could well degrade in mere decades, due to quantum effects. Metals lose their precision in a similar period, plastics change composition and become brittled, explosives in the trigger can lose their precision. There are questions on this site about how long a plane, or laptop, would work for, if "discovered"; the answers are usually "not that long historically speaking". Basically your nuke might be dangerous as a lump of toxic metal, but I'm dubious whether it would be capable of acting as a functional nuke. You might want to research nuclear weaponry shelf life. Moreover, even if it did, nukes are densely made - think what Ford does under a modern car bonnet, how tightly packed things are. Imagine what a nuke is like, very very densely built and much of it digitally controlled, probably inert unless triggered properly, electronics degraded and inert, no user keys or enabling procedures even if it could somehow work, and when opened, a tight tangled mess of incomprehensible wires and odd shaped materials and some very heavy metal - and those who touch it or inhale dust near it perhaps dying of toxic effects when their hands later wipe their mouth or touch food, even if they somehow don't get radiation poisoning just from being near it. I don't think they have a chance, or indeed that its plausible an old nuke could be identified as anything except a very heavy incomprehensible artifact of which everyone who has touched it dies in a horrible but unnatural manner. That's my best guess scenario. [Answer] They would have no idea whatsoever about what they were dealing with. None. Zero, nada, zilch. Some time later than the Middle Ages, people would start to recognize the conventional explosives, though the first modern-looking explosives didn't appear until the late 19th century. People wouldn't have a clue what the core was until post WWII. There are several kinds of nuclear weapon. I'll try to describe them in terms that somebody in medieval times might do, but I can't even do that because I need to say "explosive" and these people would have no clue what an explosive is. (And because I don't know what the lithium deuteride in an H-bomb actually looks like.) 1. Gun-type fission weapons like the one dropped on Hiroshima. Inside a very strong metal box, explosives are used to fire one piece of metal into a bigger piece of metal. When the two pieces of metal come together, some mysterious force makes them go bang in a really big way, way bigger than the explosives. 2. Implosion-type fission weapons like the one dropped on Nagasaki. Inside a very strong metal box, explosives are used to crush a metal sphere (hollow in later designs, with a special kind of air in the centre in even later designs) and the mysterious force does its thing again. 3. Fusion weapons. Inside an extremely strong metal box, an implosion-type fission weapon goes off and then the mysterious force starts acting on another metal box, which then does something with the white (grey?) powder (crystal?) inside that multiplies the mysterious force. But all of this is completely moot. Our mediaeval explorers wouldn't be able to get into the bomb casing because they'd have no way of cutting steel. Even if they could get in, they'd have no way of discovering that the explosives are explosives, even if they were familiar with the concept of explosives from gunpowder. The explosives used in nuclear weapons are extremely insensitive, i.e., they're extremely difficult to set off. If you set fire to them, they'll just burn. In the detonation sequence of the bomb, they're set off by discharging capacitors to put enormous currents through metal wires. Plutonium is just a dense metal. They'd have no idea that a lump of heavy lead could explode hard enough to destroy a city if you did the right thing to it. They'd have no idea that the lump of heavy lead was the thing that made them die of radiation poisoning, or that the plague they died of was radiation poisoning. If they took the thing apart, they wouldn't be able to put it back together accurately enought to make it work again. If they didn't take it apart, the only way they could discover what it was would be by somehow managing to arm and detonate it... and then they wouldn't be in a position to share their discovery. [Answer] # Not really. To understand how a nuclear weapon works, they would need an understanding of nuclear physics. That is 20th century science, and even an "inspired" medieval thinker would be unable to get the experimental data to refine this theory. The weapon also contains electronics. Understanding those would require a practical understanding of electricity, not just the concept of electrical power. Again, a medieval scholar couldn't do it, without an across-the-board improvement in the local technology. # But wait ... The nuclear weapon would contain a large amount of conventional explosives. A fictional renaissance chemist/polymath on the way to systematic chemistry *might* get some pointers towards a better chemical explosive. There are some experiments which give a clue to the nature of molecules and chemical reactions, and that different elements have [atomic weight](https://en.wikipedia.org/wiki/Standard_atomic_weight) as a multiple of half the weight of hydrogen. It might be possible to determine the elements and their proportions that go into the explosive. [Answer] They absolutely, postively would not be able to identify it. Not just as a nuclear weapon, but as a weapon in general. The concept for 99% of what makes a nuclear bomb, or any bomb for that matter, hadn't been conceived of. They'd need knowledge of heavier-than-air travel, high-grade explosives, etc. They *would*, however, be able to identify a howitzer as a very strange cannon if they have gunpowder You can get around this by having legends of such devices with suitable descriptions. [Answer] Yes. If you lay the ground for them. > > more World of Warcraft than Game of Thrones > > > Okay, that's a start. Now, it's a mediaeval-ish period, but there are nuclear weapons in the first place. Either these came from "outside" (e.g. from another planet where there was a higher level of technology) or from a more technologically advanced period (or both, as per Sheri S Tepper's *True Game* series). In a mediaeval-ish period it's perfectly sensible to have a belief in processes that can turn one element (as we understand the term today) into another. This belief is *chrysopoeia* which was described at least as far back as the classical period, grew in the mediaeval period and through to the early modern period as an essential part of the alchemical Great Work and is still believed in today by some with varying degrees of how much they hold it is literal or symbolic of spiritual change on the one hand and how much they hold it agrees or is unconnected to the current understanding of atomic decay, fission and fusion. Alchemists used a great many strange symbols, some of which survive today with different purposes (e.g. ♀, ♂ and ☿ used in biology were originally used by alchemists as well as astrologers). Modern physics and its related technologies have many strange symbols (try to consider seeing ☢ if you had no knowledge of modern science). An alchemy of a re-mediaeval period—that is, a future period in which technology has ended up at a level similar to that of the mediaeval period—that also worked would likely at least partially retain knowledge from our more technologically advanced time. At first glance (or first description to the reader) it would be much like mediaeval alchemy in combining some genuine understanding of the facts covered by natural sciences, a relatively poor understanding of the scientific method, and a bunch of weird symbols and legends of devices with great power that could transmutate metals. It could though retain enough information of the past for a device to be recognised as one that was in elder times dropped from powerful flying machines and through impure and perverted chrysopoeia bringing a rain of brimstone that felled cities far greater than any known today and a scourge of wormwood that poisoned all the peoples and the beasts in the field for miles around, salting the earth so that even crops could not grow there for many generations. As such you could: 1. Have a period that was reasonably close to mediaeval. 2. Have nuclear weapons, lying dormant. 3. Have the characters within the story recognise them as incredibly destructive things. 4. Have the reader/audience recognise them as nuclear weapons. 5. Disassembling the device to the point of guaranteeing fatal exposure to all present isn't necessary. (Not least since the idea that its a good idea to try tasting a chemical you think is likely not poisonous and the idea that metals are never poisonous both died out in chemistry more recently than you might think, and so could have returned as investigative procedures for an alchemist). [Answer] Prof. Dr. Smart Person can totally figure it out. The object is an ancient historical relic from a past culture. A physicist is *not* the person who should be handling it. Prof. Dr. Smart Person is thus an Archeologist. After lamenting the incalculable damage done to the historical site by the erstwhile looters (but, alas, it is the middle ages: they cannot be arrested for this cause the king likes his shinies), our hero begins painstakingly cataloging all remaining artifacts (e.g. walls, flooring, doors, lighting fixtures) as well as other salient historical information (boot prints in the dust, fingerprints, wear on various surfaces, humidity, air pressure, etc), though most of the latter while have been destroyed by the intrusion of the ignoramuses who pawned off the bomb to the university. Much of this work will be done not by Prof. Dr. Smart Person but by aspiring students and adjunct professors in his service. While our hero is the world authority on technologically advanced ancient civilizations, everyone in the field has their own specialization. An esteemed academic like Prof. Dr. Smart Person has all the *best* books on the subject, but there's always more to be gained from acquiring more focused texts on the subject. Using (substantial) royal funding, our hero dispatches the university's uniquely skilled Bursar to acquire relevant material from the world over, working together to discern authentic texts from hoaxes looking to make a quick buck. Coordinating his past research with all of the emerging material, Prof. Dr. Smart person comes to the conclusion that this object was, and possibly still is, a weapon of immense power-- so much so that even the ancients feared it's wrath and thousands of time-worn writings in the ancient tongue forswear its usage. The vault into which the looters forced access was an armory of sorts, as can be seen by its architectural and civic similarities to other ancient weapon caches with better-preserved documentation, and this centerpiece of the storage facility matches the scant few extant drawings of the "fire-mushroom weapon" before its use (the "fire-mushroom weapon" is believed to be the weapon forsworn in historical documents mostly by their shared cultural significance in signifying the end of the world and that the same fears seem to apply to both of them). Upon Prof. Dr. Smart Person's report to the king, the sovereign is torn. On the one hand, the weapon represents unlimited military power, and thus further delving into its secrets to unlock its use is very, very tempting. On the other hand, the King was raised with a royal education and is well aware of memorials from the end-days inscribed with such inspiring quotes as "I am become Death, the Destroyer of Worlds -- , upon seeing the first test of the Weapon" and "I am Ozymandias, King of Kings. Look upon my works, ye mighty, and weep!" and "Whosoever shall make use of the Weapon, let him be anathema", etc. Perhaps some secrets are best left unknown. In any case, the king must now decide what to do with the last remaining fire-mushroom Weapon (Order Prof. Dr. Smart Person to research methods of destruction for the artifact? Order the University to unlock its full potential? Order it sealed away in the Royal dungeons for someone else to decide what to do with?). If they go further into the research, the next step would be to excavate the surrounding area to the original find in search of further information. It is definitely reasonably possible for them to ascertain the use and operation of the missile. Of course, the missile is no longer 'nuclear'-- the past millennia have certainly reduced its radioactivity significantly and it's likely no longer capable of a full-scale detonation. If the cache had some sort of preservation method in place, then this is not a problem and the missile can be launched if a launching place can be found to launch it and its security can be bypassed (both unlikely). But in any case, they can totally figure out what it *does*. [Answer] You mentioned fantasy, which I assume includes magic, so I will use that. If this works or not depends on the magic available. If you've got some kind of almost reliable Divination magic then use it on this. A good diviner might cast spells, or pray, or whatever he does, and get a dream, which would show the effect. If he gets a good view he can see this is a weapon that can destroy large cities. If he can imagine doing various actions and determine what would result, then he can learn a lot about it. The bomb is probably not functional if it has just been sitting around. However, he should get plenty of visions about the death and sickness caused by opening the bomb and poking at the Uranium or Plutonium inside. All of this spell casting would probably take months. In the meantime the curious alchemist has probably already opened it. [Answer] For a 'simple' bomb, if they disassembled it and experimented with its pieces, they might notice that if they put some of the pieces in close proximity, it results in [criticality](https://en.wikipedia.org/wiki/Criticality_accident), causing a noticeable release of energy. They might also learn to associate subsequent radiation sickness with the incident(s). The only way I can think they would recognize it as a bomb is if a similar bomb were found at one point, news of the finding spread, then it subsequently was set off by mistake. If the descriptions match the old stories of the cursed artifact that consumed an entire city in hellfire and left behind a plague of sickness, it's plausible they would treat it as a weapon. [Answer] ## The more likely drama is a *criticality accident*. First, he'll never figure it out. I consider LSerni's scenario highly improbable. The gadget contains just a bunch of complicated gobbledygook, too inaccessible to anyone without at least 19th century sensibilities. He'd be worse off than a cargo-cult. I don't consider an [accident with the explosives](https://youtu.be/d5jxXkpstv4?t=37s) likely, because they are the best [*insensitive* explosives](http://insensitive%20munitions%20conference%202017) money can buy. But even that would only amount to the Kidman-Clooney example. Even in that case, the Pu239 dust would not kill enough people fast enough to be distinguished from the normal dying of the middle ages. Far more likely he just reduces it to a pile of parts, is either stumped or wrecks it, and never figures out the core is special other than being uncharacteristically warm. Unless he dissolves the core in acid (e.g. Aqua regia). Then it could very easily go critical in the jar because of the moderating water. It could go critical a year later as water slowly evaporates and the solution thickens. By "critical" I mean the nuclear chain reaction starts and sustains, much as it does in a power plant, presumably at a low level. It would give a blue glow and a lot of radiation and heat, people close to it would die in a week. ## *Oh, wait. They have two.* And he's taken two of them apart all the way down to the oddly warm core. And he *does what humans do with like things:* **puts them together**. What happens next depends on the physics. Could be nothing. Could be the mass becomes critical, ramping up power until the forces push the cores apart. The lethality of that depends on how hard that is. In [the Slotin accident](https://youtu.be/AQ0P7R9CfCY?t=1m22s), they stacked the deck against themselves by *not making it easy* for the criticality to disassemble itself. Our alchemist could be a great deal luckier; e.g. if one is in his hand and the unnatural effects startle him into dropping it, he might get away with it (long as he doesn't keep trying it). If he's set them both in a tight fitting wooden crate, they won't quit until they burn through the box. Eventually the energy *will* force the two cores apart, ending the criticality. **There's more**. [Water increases criticality.](https://youtu.be/r3fWhW_NsMs?t=15m30s) The pair might become critical *only* when immersed in water. Maybe it rains. Maybe the alchemist has them nestled in a wooden box, and the unnerved wife or king decides to be rid of them and throws the box in the river. **Bad plan**. *But that will still increase energy until the cores are forced apart -- right*? **Not necessarily. Near-magic could happen:** Water removes heat quite efficiently - and if it makes enough heat to boil the water, the steam bubbles *displace* water. Steam isn't water and this reduces the criticality, throttling the reaction until the steam bubbles fade and the reaction throttles up again. Meet *[negative void coefficient of reactivity](https://en.wikipedia.org/wiki/Void_coefficient)*. A modern reactor is designed to use this as an automatic, passive throttle - set the control rods in the right neighborhood and the reactor will trim itself\*\*. Depending on how the physics work out, that pair of cores could make heat for a *[really long time](https://youtu.be/yS53AA_WaUk)*. ## Why it won't nuke Little Boy and a few other early experiments were a type that simply mashed two chunks of metal together into a critical mass. Nobody makes them because they have so many problems: e.g. they can go off by accident. That could vaporize your entire stockpile, unless you want to store each weapon 5 miles apart, but then how do you guard them all? So the alchemist will never get one; they aren't made. The modern types require a flawless sequencing method - that's how Nicole Kidman made the weapon fail in the above clip. That is computerized and easy to tie into sophisticated authorization systems. What's more, America *gives the tech away for free* to any state we think might have nuclear weapons. Nobody's gonna put a user-friendly UI on a nuke - that would go against the entire concept of non-proliferation. --- \*\* This coefficient void in Russia and Canada. RBMK and CanDU reactors have *positive* void coefficients - boiling *increases* their power. [That ain't good](https://en.wikipedia.org/wiki/Chernobyl_disaster). [Answer] Realistically: No. (As the many other good answers have mentioned.) Howevever, how willing will your readers/viewers be to push the "suspension of disbelief" button in the service of advancing your storyline? In "Escape from the Planet of the Apes," Dr. Milo purportedly found Taylor's spaceship and understood it "enough," to re-launch it and escape the destruction of the world. (Ironically, the dolts that found the doomsday (nuclear) device did NOT understand it enough, and they destroyed the Milo's earth!) It may depend on the sophistication of your audience. If your audience will probably understand the basic principles behind an atomic bomb, they will laugh at the idea. But if they are not that sophisticated, they won't understand atomic principles, and it might seem plausible to them that "some really smart medieval scientist" could figure it out. There was also a "Wild Wild West" episode (<http://www.imdb.com/title/tt0080132/plotsummary?ref_=tt_ov_pl>) where the evil Dr. Michelito Loveless, Jr. creates an atomic bomb roughly a half-century before its time. This is not as far-fetched as the middle-ages, but it shows that audiences will be willing to suspend their disbelief if (1) the implausible act isn't belabored; and (2) they don't know that much about the science to appreciate the implausibility. Finally, if an atomic bomb could (somehow) make it to this world, is it that implausible that documentation or some mythology of atomic bomb theory could also make it to this world through similar mechanisms? That might be enough for a learned member of society to at least have a suspicion about what it might be. [Answer] Just a reminder -- a few people have addressed this question by stating that people in the Middle Ages would have had 'no concept of air travel' which I believe is incorrect because it confuses the question of WHAT the device is vs. how it MIGHT be delivered, since even today devices such as nuclear depth charges and atomic demolition mines do exist.) There was also a suggestion that people in the Middle Ages would have no conception of high explosives, which is strictly true, but there were plenty of examples of the use of fire (see, e.g., [Greek Fire](https://en.wikipedia.org/wiki/Greek_fire)) or gunpowder (certainly the [Chinese knew about gunpowder during the entire timeframe referenced](https://en.wikipedia.org/wiki/Early_thermal_weapons), and knowledge/use of it spread to the Muslim world by the 1200s. (Apparently, I can't post more than two links, so just look up Battle of Ain Jalut....) I'm not saying this means someone could've figured out what a nuke was by examining and disassembling one...just that a well-read scholar MIGHT have knowledge of some of the things needed to conceptualize what it was for. [Answer] Maybe they atom bomb power was witnessed by the ones who put it in the hidden dungeon. This could create religion, like in Megaton in Fallout, so the crypt would be full of mitologised descriptions of power of the bomb, maybe even with an ancient scroll with launch codes. [Answer] On it's own, it's unlikely. But... > > The biggest item catches their attention most. > > > What else is in the cache? It could contain some items that provide cryptic information about events from another world. With this, the alchemist might be able to connect some dots and figure out what this big device was supposed to do. [Answer] Arguably, whether on not they assume it's a weapon or not is less a matter of technology, and more a matter of psychology. If they are highly militarized and aggressive, then they may be inclined to see any strange object as a weapon or potential weapon. Admittedly, their best idea of how to use it would probably just be to load it in a catapult and fling it at someone, but really, is that so far off? If they managed to remove some of the protective shielding first, it might even be highly effective, even if it never actually exploded. It's fun to think a bit of the opposite scenario as well. Would a deeply peaceful future society correctly identify this as a weapon, even given their advanced technology, if the entire concept of weapons has disappeared out of the collective consciousness? [Answer] **They discovered two nukes** What if they discovered two of them, and took one away to the university for study? During the study, they accidentally set it off. The survivors put two and two together and now know what the other one is / can do. [Answer] He tries the first thing that any medivial scientist do. **Is it strange? Will burn it!** Yes, he'll try the most magical, sciency thing at his disposal and one of the most common things to experiment with, **fire**. When the thing will not be affected by a small wick, he'll try putting it in a larger bonfire and when that doesn't work he'll try to burn it at the stake and THEN he'll level the city. In the end, all thats left would be rumors of adventurers finding a "cursed" artifact which caused not only the death and destruction of many but made a populous utopia into a inhabitable wasteland. Also, god knows how unstable an old nuclear bomb can be, if not highly hazardous. Maybe it might be the opposite, maybe its been out for so long, its decayed into nothing. ]
[Question] [ Ten experts (CEOs, professors) of each of the fields of math, physics, chemistry, economics, engineering, electrical engineering, CS, sociology, psychology, art, politics and education (120 total) are sent back in time to recreate the 21st century in a different timeline. They can carry as many books and notes as they want but nothing electrical (fries the time machine). They use solar eclipses and parlor tricks to be accepted as leaders of a German tribe unconditionally. The clan has 10,000 members. Let's assume conflict between the professors and tribe members is not a factor and they all speak the same language. The experts are ageless but are sent back after 100 years. How far into the future can they push the tribe, or whoever else they conquer, in that time frame? Will more time make a difference? [Answer] **Not a full 21st century world, but we can get close to it in some ways.** 10,000 members tribe in post-glaciation Germany would be HUGE, but let's take it for a fact. One of the problems is that 10,000, even 20,000 people is not even close to enough to accomplish our task. And German lands are not fertile enough to support big preindustrial population. Here is a possible strategy for the team. Let me stress that this is not a likely outcome but rather a strategy that has a non-zero chance to be successful. **Phase I (5-10 years)** 1. Establish a position of unquestionable authority in the tribe. Establish a suitable religion (Christianity should be Ok), and people should treat the experts like prophets sent by God; 2. Organize the entire tribe in military fashion. Every member should devote his or her time to training and "godly" tasks; 3. Teach everyone common language (spoken by all experts, so, English?), common-sense rules like sanitation and military tactics; 4. Identify more talented tribe members and start training them as scientists and engineers. Regular people would be learning only necessary subjects like common language and the trade they going to be engaged in in the next 5-10 years; 5. Get agriculture going. *Experts must be able to bring with them seeds of plant cultures which were non-existent in 10000 BP, otherwise, the plan would fail*; 6. Get iron bloomeries going. Mass produce simple items like spearheads and arrowheads; 7. March entire tribe to the Southeast. With the obtained level of training and armament, it should be able to defeat any opponent and conquer any land; 8. As the march progresses, pick up new members who will be converting to the tribe's religion. Train them in common language and basic skills; 9. Eventually, conquer already populated fertile areas along the Mediterranean coast. Phase I goal accomplished - the tribe resettled itself in a fertile area and, counting conquered tribes, should grow its numbers to 50,000 members or more. All original tribe members should already be fluent in common language, with new members are quickly learning it. **Phase II (25-30 years)** 1. The experts should have new cultures' (like corn and potatoes) seeds with them. Now is the time to prepare big fields and start large scale planting; 2. Build a city with necessary infrastructure which can support a larger city (roads, water supply, basic sewer) and social institutions (church, police, fire brigade etc); 3. Wage occasional war to conquer neighbors, but mostly grow by welcoming new people via offering them security and food supply; 4. Identify nearby mineral deposits, start mining; 5. Set up large scale ironworks, chemical industry, and textile production; 6. Build ships to travel all around the Mediterranean; 7. Continue training more scientists and engineers. The new generation should be similar in aptitude to modern students. At least 10% of the population by the end of this phase should be "learned" class having what we call "professional occupation"; Phase II goal accomplished - tribe established itself as an antique style city-state with a total population over 200,000, well-supplied with food. Tech available: concrete, spinning wheel, steel, basic fertilizers, 1700s era ploughs. Metalworking and chemical engineering should already allow for the construction of firearms, although this should not be necessary at this phase. **Phase III (25-30 years)** 1. Build firearms and set up new colonies. Use conquest if more expedient; 2. In new colonies, repeat the process that was successful in the first city; 3. Start an industrial revolution. Build steam engines and factories; 4. When steel would become cheap and abundant, proceed with railroads and steamboats; 5. Extract oil and set up refineries (although Mediterranean basin is poor in oil, so gasoline-powered vehicles would be largely skipped in this scenario); 6. Set up production of magnet wire and other supply items for electrical components. Phase III goal accomplished - the tribe has turned into a Mediterranean empire with well over 1,000,000 total population. Tech available: steam engine, gas turbine, electric motor, radio, rubber, explosives, telescope, and microscope. **Phase IV (25-30 years)** 1. Build electric plants and power supply lines; 2. Convert factories and railroads to electric power; 3. Build industry for making of electronic components; 4. Build industry for plastics production; Phase IV goal accomplished - a microchip-based computer is built, a practical electric car is produced, a nuclear weapon can be built, if desired. So, in 100 years we aren't quite getting to 21 century, but we are close. A key to this scenario is quickly building a large population and educating it while trying to avoid extensive wars and epidemics. The above timeline is very aggressive and failure at any step can derail the entire process, but at least in theory it can be executed. P.S. It would be better if expert teams can be rotated. For example, 10 nuclear physicists would be essentially useless in the first 80 years, but they may be indispensable in the last 10. [Answer] You can't get anywhere close to that technology level. The best you could do is work to increase their life expectancy. Teach them farming. Teach them how to get water from a river into their fields. Teach them about cleanliness and basic first aid medical care. If your group of people can boost the life expectancy long enough to actually have grandparents. Then you reach a very high productivity time where children learn from their elders, while the fit people are out working the fields and creating food. Once all the basic needs are taken care of, the population will grow, and the intelligence will grow with it. The old saying is very true, give a man a fish, he eats for a day, teach him to fish, he eats for a lifetime. A bonus would be if you can invent a religion that supports the growth of science and technology without destroying the Earth. If you can modify your situation slightly to be able to bring animals like sheep, chickens and cows, that would help a lot. [Answer] # No. But I'm answering this from a different perspective: world population. 10,000 years ago, the world population was around *10-20 million.* And this population was spread across the globe. Your experts would only find small villages, consisting on average of several hundred people at most. Even if your experts could convince everyone to do exactly as they instructed, such little manpower would not enable the 21st century to be recreated in only 100 years. It just can't be done. Recreating the 21st century would still take thousands of years or longer, even with the growth of technology caused by your experts. This is due to the lack of human resources needed to create the technologies at the rate needed to do so. [Answer] Let's manage our expectations a little, and consider a fairly discrete (but certainly iconic) 21st century technology: firearms. But let's manage expectations further and try to create a modern firearm's 14th-century ancestor: the cannon. A cannon is, crudely, a lump of metal with a big hole at one end and a tiny hole at the other, into which you pour gunpowder, wadding and a roughly-spherical shot; then you point the big hole at the enemy and put fire into the small hole. These sound like simple requirements, but a 8000BCE Germanic tribe is only able to deliver you the last two: they controlled fire, and they'd be able to weave you *something* to use as wadding. Gunpowder and the cannon barrel are your main challenges. To make gunpowder you need saltpetre, sulfur and charcoal. Charcoal wasn't yet invented, but its production technique is not difficult and you could set up a charcoal kiln with stone-age tools. Make sure one of your time travellers understands how to make and run a charcoal kiln (maybe this could be a job for one of the CEOs :p). They'll probably be managing several hundred people in the charcoal production pipeline, most of whom will actually be woodcutters (felling trees with stone axes is hard work, and since the only domesticated animal at this time is the goat, moving them manually is even harder). In fact, since that's a really fundamental requirement, set another one of the CEOs the task of teaching the domestication of animals. In 5-10 years the productivity of this foundation level of civilisation will shoot up. Saltpetre is potassium nitrate, which can be mined from caves inhabited by certain types of bat, or (more practically) manufactured in pits filled with manure, urine and straw. Sounds like you'll definitely need those domesticated animals then, and this sounds like *exactly* the sort of enterprise that is calling out for a CEO's talents. Most of the workers they'll be leading here will be keeping the pits moist with urine (they take a year each to fully decompose) and then leaching the output with water (you could maybe build a watermill to assist with some of the heavy lifting here, finally a job for an engineer). This method requires potash to convert the calcium nitrate to potassium nitrate, though, so you'll need a separate industry for that. Potash is usually shaft-mined, and here you encounter all the same problem as you'll find trying to mine iron ore for the cannon barrel (which we haven't even started on yet): building a whole mining infrastructure with stone-age tools. Frankly, building and maintaining a single deep mine with all its supporting industries could occupy your entire tribe; I'm actually going to handwave over this part. Sulfur, fortunately, is abundant at the surface and can be easily collected by hand, although it would again be back-breaking work. You'll need to crush and grind it to a powder and do your best to remove impurities. Let's take stock. You've employed probably over a thousand of your tribesmen and half a dozen of your time travellers, building up industries that will produce raw materials that might allow you to create a raw material that forms *one of the simplest components* of an invention that's *a thousand years* simpler than your target timeframe. These industries will take a couple of years to get up to speed before they are producing the raw materials that could be used to *start building up* their dependent industries. It would be astonishing how much progress, relatively speaking, the time travellers could achieve in a century. But it would be equally remarkable how far they still had to go. One good thing does come out of all this, though: your cohort of CEOs would have plenty of valuable jobs to do... [Answer] ## No, As it is you will be lucky to have any impact at all. **You have a lot of dead weight and you are missing the most important fields.** **Things your forgot** 1. The first thing you need is better food production, for that you need **biologists, agricultural scientists and soil scientists**. without them, most of your effort is wasted and you may do more harm than good. The society may not be able to support your experts without better food production. Food ALWAYS comes first, people need to be fed before you worry about anything your experts can do. 10,000 years ago in Germany they would have neither plows nor oxen to pull them, so you need to domesticate animals (or travel across Europe) to even start improving farms. 2. the second thing you need is **geologists**, that lets you get raw materials for fertilizer, metals, chemistry, and good old drinking water. Before the advent of geology finding minerals was down to luck and your chemists are going to be hamstrung. Also I assume chemists included metallurgists, if not that is a huge oversight. 3. Also you need **medical experts**, improving standard of living fast is the best way to ensure they both want what you are giving them and can actually put it into practice. Without them the first plague could wipe out all your work. More importantly you need people who understand nutrition, picking the wrong crops will put your hosts in worse position then before you got there. And why for the love of all that is beautiful would you not send a few **historians or anthropologists**, people who might actually be able to predict coming events and problems before they occur. **Dead weight** 1. As for dead weight criminal science\* and art will be basically useless in the setting, criminal science doesn't have any of the tools or infrastructure needed to have any impact, especially if you already have politicians, nor do they really bring anything unique to the table. \* If CS means computer science, then you want a few of them but not ten, they will spend the vast majority of the time being useless. 2. Your hosts will have artists so your not gaining anything by bringing more. 3. You don't need both 10 political experts and 10 economists, if your political experts don't understand economics they weren't worth bringing along. 4. Mathematics will be useful but not enough that you need 10 mathematicians, you can probably half that number or more the applications will see a lot of cross compatibility with your engineers. Your electrical engineers are just dead weight for a good long time, especially without the aforementioned experts needed to actually start advancing technology. **How to fix it.** Drop artists and all or most of your CS, and at least half your economists and psychological scientists as well as half your mathematicians. Replace them with agricultural scientists, geologists, medical experts, and anthropologists/historians. You can drop a few electrical engineers and political scientists to make up the difference. If you have some room to squeeze a few full fledged biologists in, even better. Honestly, you could probably drop a lot of the late game applications down to 1-2 individuals per field, physics is going to be largely covered by engineering, by the time tech advances enough for actual physicists to come into play you should be training up a whole batch of native scientists. Ditto for computer science and to a lesser extent psychology. Even 10 educators may be overkill since educators can teach up new educators relatively quickly (compared to some of the other skills) and and most of your experts should be cross trained in education, so your late game experts should be acting as educators for a good long while. Ideally you could drop a few experts and fill their seat with expertly chosen seeds. Maybe even a few oxen. You'll get more bang for your buck if you rely mostly on books for some of the more non-interpretive sciences and start with a huge boost in agricultural output and infrastructure. Even then 100 years is unattainable, too much of modern technology relies on a huge population of specialists, you just can't get the numbers fast enough. You need millions of trained specialized people to support modern technology. [Answer] # Energy I think other answers do a pretty good job of covering most of the issues. I would just like to add a few points: 1. The biggest bottleneck to the advance of civilization is the available energy 2. The biggest bottleneck to a fast-forward of civilization is domestication Major advances in human history usually occur when humans learn to harness a new energy source, whether it's fire (from wood, peat, animal dung), water (dams, water wheels), animals (draft horses, cows, etc.), fossil fuel (coal, oil), steam, nuclear, etc. # Food Food/agriculture is, of course, the most essential energy source, as it is necessary to maintain the most important machine in your plan: the humans. However, despite the popularity of slavery over much of early human history, humans are not actually the best draft animals. They have fairly picky food requirements compared to herbivores, they mature slowly, and they are on the weaker side when it comes to muscle density/power-to-weight. Your enterprise will go much faster if you can herd and harness draft animals. But first, just think about something simple like your basic cheeseburger. You also want cattle because they give you high-quality protein and fat via beef and milk. This alone solves a good chunk of your food problem. Growing a cow is roughly equivalent to feeding several humans on wild pastures. Given the primitive state of technology, you need every bootstrapping advantage you can get. # Draft Power You should be able to build crude windmills and water wheels even with stone age technology. This will give you some decent energy with a modest investment of time and effort. Of course, you need the relevant wind and water resources nearby, but you can always relocate your budding civilization to favorable locations. It should also be very feasible to build low, basic dams in 100 years on at least small to medium size rivers. This should give you pretty significant draft power near such rivers. Unfortunately, a windmill is not very useful for plowing fields, which you need to be doing pretty heavily to start up agriculture. You need *mobile power*. You need *draft animals*. And this is where things get tricky. While human plow teams can certainly do the job inefficiently, they aren't going to do it nearly as well as oxen that you can feed on wild pastures/hay. And animals have not been domesticated 10 kya (except maybe cats, but I'd really love to see a plow team of cats!!!). # Domestication We don't know exactly how long it takes to domesticate an animals, but even the most optimistic estimates would be on the order of dozens of generations. It may have taken more than 1000 years to [domesticate chickens](https://en.wikipedia.org/wiki/Domestication_of_animals#Commensal_pathway). While you can cheat on the plant species by bringing seeds, as others have suggested, it is probably also highly desirable to bring a box of newly hatched chicks. A diverse population of baby pigs, cows and horses would also get you around the domestication trap, but now size is a considerable constraint. # Time Machine You obviously wanted to limit the technology that the time travelers could bring with them, to see how far they could get on a "pure knowledge bootstrap". Well, seeds or chicks/calfs/lambs could be seen as "cheating" in this respect. If not, then you must also consider other "non-electrical" cheats, like a hammer and a saw. Obviously, bringing a few steel saws, a few smithing hammers, chisels, and other passive tools would be a massive help in making precision cuts for your mills, quarrying stone for dams/bridges/foundations/etc. If you think about how labor intensive the production of a single stone hammer is, you can see that even if you are able to build a primitive bloomery, you'll still need a fair number of stone tools to make productive use of the crude iron you're able to produce. You can expect most useful, productive stone tools to take hundreds, if not thousands of hours to produce. Just getting *out* of the Stone Age is going to take a lot of back-breaking manual labor! # Population Growth As many have noted, one of the biggest bottlenecks to industrialization is raw population size. A modern economy has thousands of niches which must be filled by large numbers of workers. 10k citizens may sound like a lot of people to you, but only because you live in a globalized society. You don't need all 7+ billion people to produce the computer that you wrote this question on, but you would be hard-pressed to do it with less than a million. You need mines all over the world to access productive sources of rare earth elements, and so at some point you will need a truly global population. While you probably don't need the entire Isle of Britain to launch an industrial revolution, it should be instructive to note that in the 1800s, the UK had a population between 10 and 15 million citizens. I would be very impressed if you could repeat that feat with 10% of their population. Now, Seallussus did some math on population, and I will finish the math. If we define a 15-year generation, then you can fit 6 generations in 90 years. With a 10x growth rate per generation, you get a $10^6$, or 1 million x population growth in less than a century! That's pretty good, but it requires each woman to *average* 20 children, which is about 1 child per year for 20 years, from 15-35. If women continue to bear children until menopause, you get some wiggle room for infant mortality, occasional infertility, accidental premature deaths, etc. Frankly, I think that an average of 20 children per woman is pushing the limits of human capability. Although a woman is attested to have birthed a whopping [69 children](https://en.wikipedia.org/wiki/List_of_people_with_the_most_children) (no, that's not a joke), the fact that the list includes women who had "merely" 20 children suggests that this is pretty unusual. Modern societies have a high of 6-7 children per woman (c.f. Niger). Thus, I find 10 children per woman to be near the edge of believability, especially for an entire civilization. This only gives you a 5x multiplier, and $5^6 = 15,625$. Fortunately, that still gives you a population of 15+ *million* citizens, which, as we saw above, is right about the population of Britain during the Industrial Revolution. The 1,000,000 x multiplier would give a population of 10 *billion*, which isn't plausible unless you *really* nailed every single technology in perfect synchrony and spread across the globe in 100 years. Note that if a woman has 10 children, the next generation will have 10x the people, but only half of them will be females (on average), so this only results in a long-term growth of 5x. But, *each generation* will actually have 2x the predicted population because of all those useless, non-birthing males sitting around watching football and demanding beer. So you could lower the birth rate even more to 8 children per woman, for a 4x generation multiplier, or $4^6 = 4,096$x total multiplier, giving a final generation population of about 8.2 million citizens. This is well within the realm of plausible birth rates, and still gives you a very useful population size. # War Although most other answers mention war, I think your story would be much more awesome if your civilization simply awed would-be competitors with their awesomeness, and everyone wanted to join under peaceful conditions. It would also save significant resources if they didn't have to divert time and materials to swords, armor, and guns. Remember, you not only have a technology race on your hands, but a population race. The rest of the world is not going to be enjoying your 8x technology-driven population boom, so any armed conflict is going to be a hit to your population growth/target. # Traveler Demographics Totally agree with the answers which value CEOs near the bottom of the ladder of usefulness. You want agricultural scientists, geologists, metallurgists, chemists, doctors (both to treat the existing population and to teach), but 1 thing more than all the rest: teachers! You see, trying to teach adult stone age humans English (or any other language) is going to be a constant uphill battle. Teaching children, on the other hand, shouldn't be that much more difficult than teaching children today. After all, we mostly carry around cave man brains to school. So, consider the first generation on arrival as your least-useful bootstrappers. They can do grunt work via mime and direct apprenticeship, but probably not worth it to try teaching them to read and inspect blueprints. # Teachers! On the other hand, you need the women to pump out babies like they are going out of style, and you want every one of those kids to have a 21st century education, to the extent you can make that possible. Assuming your population has mostly uniform ages from 0-60, you will have 1,000 children (about 10% of the population) aged 6-12. If you bring 50 teachers, you can maintain a student:teacher ratio of 20:1. Not ideal, but pretty typical for a modern day classroom. But wait! That's not enough! You don't want to quit with just an elementary education! You want to give them at least 12 years of instruction, which will require 2x the teachers to maintain the class size...that's 100 teachers! But now you have a problem...the next generation is going to be 4x the size, and you can't bring 400 teachers. You need to *train teachers*, and to do that well, you need more than 12 years of instruction. You need closer to 18 years. So you probably need to increase class sizes to 30:1, because not only do you need 300 *new teachers* from this generation, you will want scientists, mathematicians, engineers, biochemists, and everything else as well! So, you have 3,000 citizens in the range 6-24, and 100 teachers each teaching a class of 30 students, which I'd say is on the edge of practicality. And 20 folks left over to bootstrap iron-making, geological exploration, sanitation, agriculture, and everything else you need. I can tell you right now that none of them need to be (or ought to be) CEOs, artists, or philosophers. [Answer] Will they be able to recreate the 21st century? ***No, not even close*** They could definitely bring major advancements and insights (better weaponry, cleanliness and basic healthcare, etc) which would make that tribe one of the greatest in it's time. *Maybe* they could get to the first industrial revolution, but definitely not the second. It wouldn't change as much as you think. Most modern advancements require complex machining and manufacturing processes which themselves require different metals and resources: that is, resources that require collaboration from many societies around the earth. One of the key things is trade and collaboration. In ancient times you might get a few tribes working together, but some other tribe may be incredibly violent (heck, the Vikings showed up out of nowhere during the Reconquista and caused problems for both the Christians and Muslims in Spain). Our modern advancements rely on large amounts of trade between states and countries. Most of the food we eat is not natural to where we are; we move food around from everywhere else. Those farms grow large amounts of that food because we give them resources *they want*. No amount of knowledge or insight into technology will make people suddenly all participate in major national trade like that. Worse, when someone gets ahead, another tribe will try to kill everyone and steal it because back then *they could get away with it*. Without the ability to bring resources through time with you, *you're limited by what's available*. [Answer] No There is ***way*** more knowledge between 8000BC and now than you could possibly stuff into any 120 people, no matter how smart they are. And they won't be around long enough to spread everything that they know to others. Just for reference, a child today goes to school for ~12 years, followed by 4 years of university education, followed by maybe some 4+ years of graduate education. This is what it takes to educate one person with all of the advantages of 21st century technology, in a city packed with educated people, computers, and the like. 120 people couldn't even form a decent-sized university. Also, if you want to invent things, you're going to need materials. Digging metals out of the ground, chopping down trees, making cement all takes time. And it will be extremely slow and inefficient if you're trying to get a Stone Age tribe to do it while teaching them at the same time. Even if you knew how to make all these awesome things, it would take forever to get the materials for you to even begin building physical prototypes. [Answer] Some more expertises that you will need: * hand-to-hand combat. Multiplies your ability to resist invasions. Or "pacify" neighbors for extra labor force. Teach self-defense to your other experts. * mineralogist/geologist. Where are you going to place the mines for each different material? Already mentioned by @John You also need a map of natural resources, as mentioned by @Seallussus . Unless you like scouting millions of Hectareas of wild forest & mountain. * oven maker. you need to build mud/brick ovens powered by wood. Different specs for bread making, pottery making, smelting, cooking. * metallurgists/armorers. The judges of that TV contest where they manufacture different types of swords. * medics/nurses. If one of the other experts gets a bad cut, they might bleed to death or die from infection/gangrene. * survival specialist. Teach other experts how not to get lost/killed in the forest. * forrester. Germany has, like, a lot of trees. How are going to use all that wood? Deforestation, rotation of fields, which trees to cut, easier ways to cut/transport/etc. How do I produce vegetable carbon in safe and efficient way? * carpenter. What types of wood are needed for each manufacturing? * artisan. How do you manufacture skin & paper from scratch? What processes are already known to succeed/fail? People from medieval recreation fairs might have a lot of knowledge that you need and is hard to find from books. * weaver. One specialized on medieval or survivalist. * cook. Teach new recipes, exploit foodstuffs that are currently not used due to tradition/ignorance. * fisherman. modern tactics for nets & hooks. Practical knowledge, ability to show by doing. * builder/architect. You don't want your experts to live in old wooden huts prone to infestations of bugs, right? Or asphyxiated because their new chimney was badly-designed. People wil appreciate if can you build them bigger/better/warmer houses. Other materials: * yeast: needed for yoghurt & bread (also cheese?). There are different types with different results. Different yeasts with different treatments, will give widely different results: arab bread, mother mass bread, etc. What about penicillin? * diamond tips: can write on any stone, lasts a very long time [Answer] Before these people in the past can focus on absorbing all the new information your professors have they must first satisfy their own needs. The ancient folk don't have time to sit around and listen to these professors, they have a proven way of life that demands large amounts of time tending crops and animals and producing their daily tools. As such I would expect most of the professors' time to be spent enhancing the existing farming and tool making techniques rather than introducing radical new changes that would threaten to have too large an overhead for the ancient people to maintain without causing mass starvation. The most you could expect in 100 years is that the ancient folk have some basic hygiene knowledge and slightly better farming, I wouldn't even expect that the experts have a chance to develop new tools or production. [Answer] No. The experts are experts on a specific society, the late industrial western civilization. In the past they won't have the infrastructure that their expertise relies upon. Example: Metals. Even if they know where the ores are they need people to dig the ore, then refine it without the refining tools we have and then forge the metal without the forging tools we have. They won't be using armed concrete, for example, for a long time. They have to build EVERYTHING. They may set examples and pass teachings in very useful areas like sanitation and optics (to create glasses and extend the productive lifespan of the ancient wisemen) but that's it. Another thing is the persistent idea in other answers that if the experts create a religion to fool/guide the primitive barbarians and make the experts' books the holy scripture then everything will work out. That's very wrong, based in a late industrial western vision of what is religion, derived from the marxist idea that religions are ideologies (false sciences created to acquire and mantain power). Things were different in the ancient world and the people looked for certain signs of divine/magical/demonic action, like the discussions in Jamblicus' book, On The Mysteries. Your experts won't fool the ancient wisemen if they try to pull the "create religion" stunt and will end up executed for blasphemy. So the best course of action is to cooperate with the wisemen, try to pass knowledge that has immediate utility, like the sanitation, optics, pasteurization and, should the region where the experts appeared have advanced iron age metallurgy, electricity/radio. You will never recreate 21th century tech but will empower the region with less mortality from diseases (sanitation/pasteurization), more productive wisemen(glasses), better communications(telescopes and telegraphs). In time this region will have a population boom and will be able to support it's own technological development, following it's own path. [Answer] Maybe, but as others have pointed out, your focus is wrong. If they can bring back non-tech items other than books, then I think this might be possible. If they could bring back modern strains of crops (corn, barley, oats, potato, apple, oranges, etc...) and modern farm animals (chickens, cows, pigs, horses, oxen, and sheep mostly) this would go a LONG way toward establishing a stable food supply for the native population. I would say with the above resources (and the knowledge of modern fertilization/crop rotation), you could set up a retively modern food supply in 5-10 years. The next order of buisness would be educating the native population, basics at first, have them become accustom to the animals, and the new farming techniques. while adults are learning and working then the real work of teaching the children to read would begin. Im not sure how far you would get with the first generation which is why you would start the education as quickly as possible and plan on the children of the children you first taught being the ones who can start doing real work/learning. I would expect to be able to reliably have the 2nd generation reading around year(s) 20-25. Once you have a stable food supply and the beginnings of an educated population, the real work, and therefore the real progress, can begin. You can then introduce fire, the wheel, the waterwheel, metalurgy, optics, the compass, paper, books, the printing press, electricity, the steam engine, the telephone, vaccination, refridgeration, air travel, penicillin, fission, semiconductors, computers, the internet, space travel... Once the native population can read and educate themselves, they will just need the books (hence the printing press) to keep going. So after a few more generations of the native population go by, you should be nearly at the 100 year mark for the experiment, and if they're not up to "21st century level", then they would be in the next few generations. [Answer] It would make much more sense to send back people with useful skills related to survival and building than a lot of academics with nothing to offer. What are you expecting art professors to do in 10,000 BC? Or an electrical engineer in a place with no metal? What useful skills does a politics professor have outside of academia? (There's a reason that's the only place you find them). I image your party would be found out and die off fairly quickly. Send back people with skills in smallholdings, animal husbandry, medicine, midwifery , public healthy, construction from scratch and a whole lot of military types and your tribe might thrive. Or ir might not. There is a lot of luck involved. [Answer] I think there a couple of points that is not mentioned here. This is not much of a detailed plan, but rather just a couple of important points. * How ruthless are your group? Are they willing to use slavery? Are they willing to allow polygamy? Would they use diplomacy or war to gain lands?...etc. * We tend to think of a skilled laborer as an adult with years of knowledge and both theoretical and practical knowledge. Well. Get a 9 year old, teach him about your sophisticated metal working methods. Then tell me how long would it take him to understand them and become proficient. Not long I'd wager. * Aside from programming or genetic engineering or stuff like that. Most, if not all, of our knowledge is fairly simple once we know about it. Penicillin is not magic, Newtons laws are not magic...etc. So knowing that electricity exists or that you need to do this and that to make a rifle...etc makes it a matter of how do I produce those with the available tools * Similar to the points above. You can start your empires training at a young age. The younger disciples would learn from the age of 9-10 to the age of 15-16 That mean means that you have someone with the knowledge and resources of a medieval blacksmith at the age of 20. At 30 they can start making muskets. * Population growth. How long would it take to increase your population with your improved healthcare and food surpluses? Well. It takes about 13-16 year, or even less if we abandon our current standards, for a girl to become of child childbearing age. And with the previous statements about how serious your government are about population, then marriage is legally required and none can remain single, females at least, and none can abstain from having children. She then takes less than a year to bring a child to the world that would take about 15 years to turn into a master in their discipline. I'm no mathematician. So my numbers would be off. But here is an attempt. Assuming an average age of mere 55, seems a reasonable number with our improvements, and that a woman become childbearing at the age of 15. Now assuming she is required by law to have a child every 2 years. Then it's about 20 child in here 55 years. Tough but not impossible. So about 20 of every single female of the first generation. So assuming your basic population of 10000 and assuming a neat 50/50 split, then your very limited basic tribe can supply about 75000 child. Heck. Let's cut the 25000. So 50000? Now the first generation would be 25000 females? They take about 15 years to start the cycle again, right? Now there is even more. Because we already talked about aggressive expansion. So while your starting pool is limited, once you start conquering new lands you can start having millions of population in half a century. And again with much better healthcare you can actually keep people alive for longer and eliminate the dreaded fear of childbirth. So a combination of war, slavery and aggressive populating would get you staggering numbers in 50 years. * War fatalities. How many on the ancient battlefield died because of a silly disease or a wound? Too many. But your improved army has better healthcare and you can actually fully cure most of your soldiers. So not only would you have more soldiers but your recovery rates would be higher. So imagine a legate with 20 of continual war experience. Now imagine that the average officer in your army is something like 6-10 years of war experience on every country in the world. * Military expansion. Genghis Khan lived for 65 years, Alexander of Macedon a mere 33 years. Neither of them knew anything that you military commanders knew. Can you even imagine the state of absolute disarray that the world was in? Honestly. I'm willing to wager that you can conquer the entire old world in less that 50 years. The biggest problem about maintaining large empires is communications and at some point you would have railroads. That's just a game changer. The Roman roads sure as heck were. Trains would be magic. And the thing is once your legion, I'll assume it's the basic unit, of 5000 can travel from Germany to Persia it a week you can effectively rule the world. * Speaking of expansion. You have a map of natural resources right? And different maps of the proper climate of each crop, right? Well. What are you waiting for! Turn an entire country to a farm, another to mines, a third to oil fields...etc. And with such a solid ruling elite you won't run into trouble. An important point here is that you are willing simply conquer at least the Mediterranean world if not most of the ancient world. And you have thousand of slave, then thousand of well supplied workers using the latest farming or mining...etc techniques...etc. * The biggest issue here is the first stage. Producing decent amounts of medicine and food and tools is vital. Since I'm not an expert on any of those subject I can't give you a detailed plan. Though of the blacksmiths of Japan found a way to make good swords with the crappy metals they have. And the Romans made concrete that we can't find out how, or how the Egyptians found a way to build the pyramids. I'm sure with perseverance, and a lot of firepower, you can give the idea a try. * Science can be fast. How long did it take us to build a car? Now from the of making a car to the making of an airplane, how long? So my final point is this. Even if it takes you 50 years to start making the more advanced stuff. Once you have the infrastructure then it's a piece of cake. [Answer] Here are some random notes on the initial bootstrapping; I don't have time on my lunch hour to think about the later steps. Some of the stuff you could do in the first year is domesticate horses, make bridles and saddles, and good bows and arrows. With that you could pretty much sweep the Eurasian landmass. (Granted not your goal, but this is basically how Proto-Indo-European was spread from Iceland to the Pacific.) (I've heard though that all domestic horses on the planet trace back to a single grandfather horse, and he might have been uniquely domesticatable. So, I'm not sure if you could have domesticated any random horse you found.) You could introduce writing pretty much day one. That'd jump you a good 80% of the way to the present day right there. Ditto sanitation (mentioned by others). I don't have a good feeling whether the language of 10k years ago was as productive as what we speak now. In other words would they need to have a modern language to start doing modern tasks, or would their old language have, say, enough prepositions to describe all the things you'd like them to do? A tricky one: are the scientists sent back in time full of poo? If so they should take care to eat all the domesticated seeds before their trip, which should pass through the digestive tract intact. If not, though, then you have a HUGE challenge: having a division of labor allowing a lot of people to work on things besides food requires those working on the food to gather a huge number of calories, which I don't think is possible without modern grains which have had millennia of selective breeding. Sure, you can introduce farming, but what would they farm? Raspberries? If you don't have the grains, I think that ends your plans right there. Even with all the books in the world, I think most of your expert's time might be devoted to gathering calories. (I've also heard that in some places this might take as little as a couple hours a day.) Pottery should also be bootstrapable year one, which would help you store food from times of plenty for times of scarcity, which would increase the number of people who could be dedicated to non-food pursuits. I think you could get bronze going quite quickly too. Portable fire with flint would be a big benefit; I don't think that existed then. To the extent you wanted to power things with hydrocarbons, I think the area around Baku had lakes of oil on the surface. You might want to head there to start your revolution. [Answer] One factor that's going to cripple your ability to recreate the modern era is your supply chain. The modern world enjoys a global economy. We trade goods and raw materials with other people from all corners of the globe. Your scenario injects a massive knowledge infusion into a small group, but the rest of the world is still the same as it was. Your uber-tribe will be able to do amazing things, but only if they're doable with the resources available in their immediate vicinity. Example: electronic components use a wide variety of elements that aren't easily obtained. For example, the primary source of gallium is bauxite, the ore used for producing aluminum. Your society won't have access to gallium until it can mine and refine aluminum (assuming it has bauxite it the first place). If you don't have it locally, you're now blocked waiting on the rest of the world to catch up with you. Even when you have the raw materials, the process of extracting and refining them is often times only economical at scale. With no external demand for refined materials, you likely won't be able to afford many basic industrial processes. [Answer] If you could take the resources available on the internet in book form--we're talking a LOT of paper--I think you would do pretty well. The first trick is to have the current generation of people concentrate on resources for training the children and some simple first generation production (Farming, creating teaching tools, mining/mineral processing, housing, etc.). If you can train the children efficiently they should be on average MUCH smarter than the average person from today and you're off to a good start. After 15-20 years of training the first generation of technical workers and working on the basics you should be ready to put together the next generation of tooling. After that it's just iterations and they will be comparatively fast. You won't have the sheer numbers we have today--but very few of us actually push progress, we waste most of our energy sustaining our huge population. if everyone was working on the next generation thing constantly without waiting for "innovation", we'd have been moving at a much faster pace between the 000s and 1920, most of that progress could have probably been accomplished by a few thousand people in 20 years or so. The biggest problem here is getting enough metal out of the ground and processed--mining has always been very manpower intensive and that hasn't really changed. I can only hope newer efficiencies and processes don't require as much. The stuff from the end of the depression on has been at a faster pace, but we did it in 100 years, a well-trained thousand people with all the "Discoveries" pre-discovered should be able to do it much quicker, but this is where iterations can get tough (creating the machines you need to build the machines that can build the equipment you actually want). I'm not sure the computer stuff could be sped up too much, you just need iterations. Perhaps this is where someone with the experience that Elon Musk has with his battery factory where innovation was "planed for" could make a huge difference. [Answer] They would have to write a book for the tribesmen, that would be copied on a printing press. Having made tempered steel chisels and carved the most incredible stone carvings ever, you would essentially be the de-facto friendly alien from another planet. Together with knives, pots, pans, a saw-mill to make wooden planks, they wouldn't throw engraved illustrations of the technology on the floor and walk off. 10 professors armed with digital files could indeed reprint a vast library of knowledge, detailing most alloys, chemistries, physics, machines, political laws, biotechnology, medecine, used in the 21st century. The development guide would have to include some transition technologies like ox ploughs and field medecine. 10 million pages would get them up to the 1970's / 1990's. To get the tribe's interest and attention, the library would have to include maps of the world, statute books on world dominion, military defense / attack tools, carts, trucks, windmills, ox ploughs, wine presses, food processing, cranes, scaffolding, cements, architecture, and the library would be graded in steps of complexity. It would take at least 300 years for the tribal culture to adopt a scientific tradition. Using the printing press and the library, they could come to parity with us in 700 years or something. [Answer] Since one progress made right after another is just not how human minds work, no, not in 100 years. Instead of thinking in number-of-years think in generations. You can hyper progress one generation, lets say from hunter-gathering to farming but then you have to stop. Let dust settle. Make people see fruits of their efforts. The next generation would make no progress at all. Thats how human minds work. The generation after that will be ready for progress, mostly after the first generation die off. Look at advancement of physics in 20th century for example. Rapid progress between roughly 1890 to 1920, then nothing for long time, just stabilizing. Then starting roughly from 1970s some progress. So, first progress, just move from hunter-gathering to farming, not push any more. Second progress, metal works. Third progress, firearms. Fourth progress, engines (rails, cars but not aircrafts). Fifth progress, aircrafts. Sixth progress, space technology till 1980s level. Make progress in arts, culture, law etc go along these above progresses, in parallel, using non-science people. Also make progress in computers along the way. So, 12 generations, roughly 400 years; and thats when technology is handed over to those people, not developed by them. [Answer] No. First you are sending back the wrong people, and secondly you are sending back too few of them. And finally, 21st century technology is dependent on 21st century population. It is utterly impossible without either more people than could be put under control in that timeframe or more advanced knowledge than we currently have... Now, if you want 20th century tech, it’s another matter. What you would need to do is basically send back a small 1830’s town, with enough enough farmers/ranchers/miners to keep them supported. Now, that sounds on the face of it like a huge increase in population, and it is, but probably not as much as you are thinking. Under a 1000 puts you out of the top 100 cities by population in the US at the time. Which means that a tenfold increase would put you in the ballpark. With the increased population and the fact that you have made them all immortal apparently, you would be able to create a self supporting base that over the course of a hundred years would develop into a good size city with a low 20th century technology base. Given that, it wouldn’t even be particularly hard. Given your immortals (or even just extended lifespan), then they could spend a few decades not only working out how best to develop the technologically progression from naked people to flying, but train your entire expeditionary force in the various skills they will need. You’ll want farmers and bronc busters, miners and blacksmiths, carpenters and bowyers, potters and textile workers and as someone else pointed out, lots of teachers. Given the know-how (including experience, I would suggest 12 practice runs of the first month, 6 practice runs of the first year, and at least 1 practice runs of the first decade), it should be easy to develop what you absolutely need for low to mid 20th century tech over the course of a century —- the ability to feed and educate several hundred thousand people. You don’t need to worry about going a-viking, most of the areas population is in groups of 50-200 people, and they will come to you if you have reliable food year round. In our history, the first known cities came about 4500 years after your target date, my suggested 1200 people immediately outnumber everyone else and while fight and raiding will be known, size should protect them. BTW, if you could drop maybe a dozen or two people a month or so in advance of your target, that would be really handy in making sure everything goes smoothly. Once you’ve got your first city of 100,00 people with 1910 knowledge, you should be able to start spawning colonies around the globe without any real trouble, particularly if your immortals are still around. The colonies should be able to get started and grow much faster than the original — trade and the fact that they can start with tractors and such will allow them to draw in the required population quickly. In another hundred years it wouldn’t be surprising to have another 100 cities with populations in the hundreds of thousand. At that point you’re firmly in the 1930’s and up territory. Progress from there will depend upon local development and demand. [Answer] In the [*1632* series](https://en.wikipedia.org/wiki/1632_series) they have something of the same situation but 6 mile radius bit of USA moved from the year 2000 (or near it) and with it a town with all schools up to a high school, many small and some mid sized businesses, a power plant with enough staff to run it and so on. They land in the middle of Germany (as is now) in an area with many people who are willing to join in and manage to get over the language problems (although German of the time misses a lot of words needed.) With all those advantages over your scheme they do run into many bottle necks. You need metal to build up an industrial base. To melt metal you need to build the basic metal industry (and your Germans will have non) and for that you need people who do not only know how to melt and refine metal in theory, you need people who know all from digging out the ore, the clay to make the smelters for each of the smelters and so on. Your 120 high level specialists will likely not done any metal work with their own hands and even when they do have a hobby like primitive metals, they will likely only specialize in one kind of metal and not all. And you will get that with all fields of tech, from textiles and food to the specialist fields like computers. On top of that, (as shown in the *1632* series,) not all raw materials are available in Germany, some not even anywhere in Europe. Things like rubber, stainless steel, many food stuffs, ingredients for medications and so forth are not in Germany. And many medical supplies can not be made without a lot of 20th or 21st century equipment. Also forget operations. And your specialists will bring germs the locals have not protection against, while your specialists may get ill from what is the norm for them. I guess your specialists are way to specialized to even start the change and that they run a big risk of losing all because of disease or disaster they are not prepared for. And that is assuming that they survive the initial meeting. If I found a group of strange people in my hunting grounds, I am not sure whether I would want to meet them or just kill them. [Answer] Even if all the materials are taken care of (if you can send a hundred people a few shipping containers should be doable) is simply measuring things reliably. A human can do centimetre-scale by eye or milimetre-scale with simple tools but if you want to get more precise (and for many modern engineering things like nuts and bolts you need a order of magnitude more) you need a [micrometer](https://en.wikipedia.org/wiki/Micrometer) and those came along in the 1700s. At their time they were a marvel only possible by using the latest and greatest technology. Tell a modern engineer he'll have to build something without use of a micrometer and he'll just stare at you blankly. [Answer] **YES** The reasoning behind my YES is controversial, but even if you disagree with the reality of my hypothesis you can still use it as a plausible explanation in a work of fiction. Firstly the ability to produce metals, wire, magnetise metals, and collect/produce chemicals, all with the purpose of generating and storing electricity, could plausibly be given to Neolithic tribes 10k years ago. What this would give as a huge advantage to any one specific tribe is the ability to communicate at a distance, which would be an unsurpassable military advantage. This would plausibly result in a social structure very different to Neolithic norms. It would also put the time travelers in a situation where their knowledge and ability to maintain the equipment would make them elites. The problem is a lack of knowledge/understanding of mathematics and how a society could be shaped applied to engineering tasks, and how quickly electronics/computing could evolve. My controversial solution to this is what I believe is the explanation behind the marvels of Egyptian calculation in pyramid building, or the accuracies of Maya astronomy. Namely, **autism**. I think we have evolved not as individuals but as societies. Like beehives or anthills, humans are similar in the sense that societies have different roles and I hypothesise based on life experience that people are born with predispositions to these roles. As with wasps or bees, some are soldiers, some are queens. I think humans are born with predispositions to building, to driving (shepherding, riding), to farming and nurturing, etc. I do not believe that autism spectrum represents an 'abnormality.' I would offer the conjecture that ancient Egyptians were excellent for their time at feats such as constructing pyramids because they had an inclusive society where those on the autism spectrum were recognized for their talents and conditions were such that they could feel comfortable and be productive. Were Oracles, Seers, Prophets and Druids examples of how talented (and different) individuals were recognized in ancient times? Were the insights that Pythagoras brought merely descriptions of what the local human computers already knew intuitively, but unable to express? In the end, reality is a subjective thing that is entirely created by the computer that is your brain. You and what you live in is all 'made of' consciousness that is generated post-hoc upon receipt of sensory stimuli in the external and objective reality, to which you have no access. Everything is brain-generated. It is a computer. So autism in my opinion is a deviation from the 'norm' in allocation of computing resources. The individual may lack coordination and social awareness, but in some cases can translate from multiple languages and self-teach advanced arithmetic as a child. Could it not be the case that autism is a social evolution, a natural occurrence of a human computer so that basic mathematical and linguistic problems occurring daily in simple societies can be solved? A predisposition to certain abilities, for the benefit of the society, totally analogous to having a predisposition to singing/communicating, or a predisposition to strength and violence? Is it the case that autistic individuals are pushed into 'diagnostic categories' (aspergers etc) today merely because advances in computing and mathematics make them irrelevant, whereas before they were Oracles and Seers? So with this view, I think the answer is **YES**, if a society can be shaped that empowers those types of individuals in an elitist structure, which would evolve quickly once the telecommunications advantages were brought through military dominance. [Answer] In a hundred years, no. In two hundred, maybe but doubtful. Considering some of the caveats in other answers, I would say you’d need not only more time, but you’d have to find five or more villages friendly to each other and have some of your experts in each. You’d need a way to have messengers for the experts to communicate with each other. You’d have to go slowly enough to overcome the “indistinguishable from magic” problem. And you’d need to provide your benefits in sufficient quantities and low enough cost to keep other villages from obtaining them by force. (So you can concentrate on progress instead of on defense.) However, a limited threat is a good incentive to develop defense technologies. If they’re all in only one village, there’s a greater chance of invasion ruining the project, while having the growth in more than one place improves the chance of it spreading. And covering a little more area increases your supply of food and materials. If your goal is to accelerate the development of technology, maybe send some experts to that time, and some to later times to build on what the previous groups have done. And some really clever sales/propaganda people to get folks to honor/respect the experts instead of envy/resent them. [Answer] Maybe, but you're going to need more than just 1 wave of experts. So you want to create modern society, but 10,000 Before Present (B.P.) (or I guess 9,900 B.P. since you're giving them a century). Here's what you do: Send your experts back 11,000 B.P. to kick things off. Basic agriculture, hygiene, etc. Send another wave back to 10,900 B.P., to take advantage of the improvements brought on by the first group. Send another one to 10,800 B.P., 10,700, 10,600, etc. Each group should take the combined advances of all the previous groups and build upon them. (In fact you've said your group is ageless, so you could just use the same people each time.) You might even send the group to multiple different locations within the same time period so you're not just advancing one specific group of humans but all of humanity across the globe. It's going to take a lot of work, and many separate trips to many locations, but if you're careful and patient, you could pull it off and have your modern society by 9,900 B.P., but only as the culmination of a millennium of guided improvements. [Answer] No as OP's setting. 10,000 years ago it's 8000 BC, people in the Eastern Mediterranean should already know some farming/agriculture, but for a German tribe? Probably NO. What is worse is in OP's setting there's no expert for agriculture... A hunter-gatherer tribe may not even have enough food to feed the experts, actually I doubt that any hunter-gatherer tribe could reach 10,000 population. Without agriculture, there's won't be enough food. Without enough food, there won't be enough "extra" people to work on mining/blacksmith/education/research/construction...basically everything "extra". So this plan probably won't work from the beginning. If some adjustments can be made, like allow time travellers to bring some seeds/animals/basic tools, pick more experts from some fields like agriculture/medical/mining and metallurgy/...etc, my personal guess is they can reach tech level around 1800, or even 1900 in 100 years. Source: [History of agriculture](https://en.wikipedia.org/wiki/History_of_agriculture) [Size of hunter-gatherer tribe](https://www.quora.com/How-large-were-groups-of-people-when-they-were-still-hunter-gatherers) [Answer] It would definetly be possible All you need is humans and 10000 members is quite a large number. lets say, in worst case 1/3 are old people 1/3 are children, 1/3 are adults lets take the adult women from the equation, and you would have at least 1600 men to do the heavy work needed to start the industrial revolution. Which is not bad. The children would be able to get some good education, which would make everything easier in the following years. As for the adult women, well, they would probably end up being full time mothers, as you would need to grow the population, to speed up everything. So yea, they could. Though food plays a huge factor in here, as the crops from back then would be quite bad, compared to the ones that we have today. Even then I still believe they would be able to do it, even though the start would be quite slow, until the food issue would be solved. And to answer your last question. More time wouldn't make a difference(besides for them being there to steer them in the right direction in some cases, like some disease/war...), since all they would need to do there is to pass the knowledge to the tribe, which wouldn't take that long(maybe 30 years??) [Answer] ## **A Resounding YES** **As per the OP's question, we only need to replicate the 21st Century and populate it, we don't need to make the same mistakes, trial and errors, wars, dead end results or bad theories/misconceptions that normal development requires.** Many developments that constitute the modern structure of society have been [developed in the last 100 years](http://www.londonip.co.uk/20-groundbreaking-inventions-from-the-last-100-years/). Compared to 1919, 2019 has developed tremendously. Replicating the development within this period should be much easier considering knowledge already gained, and no need to make mistakes. Many answers assume we need to slowly develop the Germanic tribe in the same way that it took 10,000 years to do so, however we only need to teach them what they need to know, which is what we know now. The rest is simply structure. For instance, teaching a young child in the tribe as if he/she were modernly educated would achieve a good level of knowledge and education equivalent to today. The rest is environmental, with which the original 120 founders of society need to start work on. So, in order to achieve this, we need to send back the following 120 people: * 20 Leaders: People who are expert at leadership, trained specifically in leading people, convincing them of cause, and good project management skills. Preferably they have degrees in political science and/or military officer training. These people will coordinate others in the group of 120. The reason we need 20 is that 1:8 is a good command ratio. This means each group of 10 experts needs 2 of these. * 50 Workers/Professionals: These are people who need to build the factories, mines, smelting and processing plants, to initially make materials than make machines capable of producing higher level products. Each discipline in the OP's question would have 4 of these. * 50 Teachers: These people need to educate the tribes people. With a group of 50, and a staff to student ratio of 1:30, you could teach 1500 students in the first generation. These would go on to teach a further 45,000 in the second, and more in the third. Their teachings would be the same level of knowledge as 21st century primary, secondary and tertiary teachings. Initial classes would be limited by scarce technology but as the Workers group, later assisted by educated tribesmen, start to produce results these can be transferred to education. Again, it must be stressed that you don't need to develop everything up to 21st Century, you only need to replicate it as it is now, and train the native population to use it. Plus you have 100 years to smooth the society out. With no conflict postulated as per the OP's question and the tribesmen already convinced to follow you, and 120 extremely smart experts in their fields, proportioned as above, you should be able to replicate, at least a smaller scale part of, the 21st Century. [Answer] The answer is No, you cannot achieve 21st century civilization starting with nothing but 10,000 people in the Stone Age. The reason: you need population growth that can't be achieved in the Stone Age. Every answer you've received that has explained population growth has given you good information about how people die, except that they were generous when it came to mortality rates. None of the answers that I saw told you to bring an obstetrician as one of your specialists. I've studied child and maternal mortality a little bit. Six to eight children per woman is about right if the husband is being considerate. But you all have forgotten that 1 out of 4 women die in labor without modern cleanliness and equipment. If we assume that the one woman is dying at the end of her child-bearing years, then she and the other 3 living women will have between them 24 to 32 births. If she dies at the beginning, then they will have 18 to 24 births. That doesn't mean the children will grow up. 1 in 5 children died before the age of 5, and they died from things like dysentery, croup, cholera, teething (!), whooping cough, measles, fever, and meningitis. In some places, it was closer to 1 in 3 dying before the age of 5. You can find on the internet something called a mortality schedule, sometimes called a morbidity table, that shows what people died of, how long they had been ill, what age and race they were, and lots of other factors. Genealogical sites have these. If you look one up from, say, 1850, you'll be shocked at how many die while still infants and toddlers. Even "at the beginning of the 20th century, for every 1000 live births, six to nine women in the United States died of pregnancy-related complications, and approximately 100 infants died before age 1 year" (that's at the rate of 1 out of 10). This is from "Achievements in Public Health: 1900-1999" from the CDC. So, in order to achieve the explosive population growth needed for 21st century technology, you have to improve not only cleanliness but also the general medical environment and equipment to 21st century standards. Sanitization isn't going to happen under Stone Age conditions. [Answer] No. I don't think you could do it even if you used a shorter 'way back' Let's try roman times: * Well organized society. * Lots of workers. * Has a working economy with division of labour and money. This last item makes scaling things up MUCH faster, since one wealthy person can command the work of thousands. Even then you have some major problems: * You have a pile of books. Class sets? * How long does it take your 120 people to teach your 10,000 to speak English? Some people pick up a new language quickly. Most do not. Catch them as kids. In third world countries, with good community support, a teacher can handle a class of 30-50. If ALL of your 120 cadre were teaching full time, it takes 10 years to get 6000 kids who can read and write. * How long does it take to introduce printing? You're going to need paper. Look at the process to copy a book by hand, including making the parchment. A book's value is measured in at very least man-months. * You're missing a lot of trades. Your 120 people needs to include a whole raft of engineers. More: Historical engineers. You need a bunch of shade tree mechanics. Black smiths. Masons. Millwrights. Just what goes into making paper. How many whole industries do you have to make to make the paper to make the books so that you can make those whole industries. Third world countries often skip forward to modern times in a hurry, but they are being externally supported. E.g. One project is to put a solar cell, a battery and a moderately bright LED in every home in a village. Tiny step that costs a few dollars per house -- less than the price of a land mine. But this allows people to work, and read after dark. But to provide that you need the whole infrastructure of the first world. This increases the useful waking time by about 1/3. Equivalent to extending their lives by a couple of decades. Lots of third world projects to do things like make well pumps from local materials. Steel pipe. Parts of old cars. First world junk. When you go back, you won't have the scrap heaps to work with. Huge problem of, "we know better" on both sides. If you haven't lived with change, anything new is a threat. Your cadres has to learn the culture deeply to effect change on it. In the last half of the last century agronomists bred a rice that had enough vitamin B6 to prevent the wide spread deficiency disease then extant in SE asia. People wouldn't eat it. Had a different texture from the rice they were used to. (My local super market has 15 different kinds of rice that are sold in 10-20 kilo bags. Our city has a lot of asians, from many countries and cultures.) * Lots of things aren't in books, but are skills that are passed down from one practitioner to another. There was a TV series about trying to recreate stuff based on te tech of the time. Ok. So how would you do it, and how much could you get done. * Don't send them all to the same time. Start by sending a few -- 1-2 -- to, say 30 BC. Their job is to learn Latin as spoken in Rome. They come with a small pile of portable wealth to set themselves up. Probably not Rome but a villa outside the city. Next people come 5 years later. (They can be 10 minutes apart at this end of history.) They come to the villa, and for the first 6 months learn Latin, and the local culture. Big influx of slaves available from the Gallic wars. This group is buying slaves, and putting them to work building the buildings that will eventually become schools, factories etc. Probably best if this villa is on a river with enough of a flow to power multiple water wheels. Power in Rome was based on wealth. Some of your people pose as traders to convert future wealth into forms that are easily used as money here. Gold and silver work. I suspect that artificial gems are better. Coloured gems were more prized than clear. Synthetic sapphire (many colours) are about $1 each for a 1 x .5 cm stone. You could fake up a mine easily enough. Setting up a dye works to colour cloth would make enormous amounts of money. Tyrian purple was at least 3 times the price of gold at the time. Synthetic indigo (another prized colour) runs about $4/pound here. It takes a gram to dye a pair of blue jeans. There are a whole bunch of dyes that can be made with analine that are intense, cheap, and enduring. This is 1860's chemical tech. Meanwhile, one of the ways you govern your slaves is to tell them that they are free in some number of years. After that you offer to pay them. While this is happening all the slaves kids are in your schools, learning to read, do arithmetic the new way (arabic numbers) and use logic. Books are still scarce, but slates dipped in wax work for temporary records and training. Meanwhile, your historical metalurgist is trying to recruit the locals and teach them how to make better alloys. You will need a massive priority list. Paper requires either sulfuric acid or lye, and cotton or woodpulp. Then you need screens to drain it on, rollers to fuse it. I suspect that paper was more critical to the explosion of books in the renaisance than the printing press was. You're going to have issues with transportation. Steel requires coke, which requires coal. From Rome I'm not sure where the nearest surface deposits of either are. Probably NOT on the Tiber River. But you're going to need tons of it. Even today water is the cheapest way to move freight. Compared to ox pulled wagons, the cost per ton-mile is tiny. I suspect that overall in a hundred years you could get a pocket of late 17th century tech. Hmm. Not going to do all your homework for you. Get a good history of technology and figure out your path, and what bits you can shortcut. ]
[Question] [ In a modern, "western" country, where can I set my secret facility so that authorities won't find me for about 30 years? The needed amount of area is relatively large, a bit less than 200 m2. The facility in itself is not particularly needy; it requires running water/electricity but nothing else. On top of that, it does not produce noise or waste, etc., so it should be possible for it to maintain quite a low profile. The real issue is that this HQ (with its machinery and all) is that it is hard to move. If authorities announce that they want to survey the area, I will have a hard time hiding everything, even knowing it 10 days in advance, so it would be better for this place to be outside of the authorities’ reach. So basically I need a place where I can get electricity and running water that local authorities will likely not reach for about 30 years. Does such a place exist? If it’s a private property, can I realistically keep all people out for such a long time? Even for things like mainteinance and upgrades of meter etc. Many modern cities have been built on top of older cities and have very complex sewer systems and catacombs; how "safe" are those spaces? What about abandoned places and buildings? [Answer] Private ranches. [Here are the ten biggest ranches in Texas.](http://www.wideopencountry.com/10-biggest-texas-ranches/) Ranging from King Ranch (911,215 acres) to Jones Ranch (255,000 acres). There are also large ranches in Oregon, Wyoming, etc. Every once in a while, these are up for sale, like the 510,000 acre Waggoner Ranch right now recently sold. Some of these even have their own electrical systems, solar and wind power, with backup power by gasoline generator. For water you can use wells, and most have large ponds on the acreage for watering cattle, or a stream. Most also have their own sewage / septic systems (not connected to the city). Food and groceries can be trucked in. You can always partition out a protected area within your acreage. Most such ranches are NOT under the jurisdiction of any city or town; just the State. With enough money for full-time lawyers, private property cannot be searched without a warrant, and a warrant is extremely difficult to get. There is also the problem of an abuse of "exigent circumstances" which lets police search without a warrant. ([Here is a paper on legal searches without a warrant](http://www.ncids.org/Defender%20Training/2004%20Fall%20Conference/Exceptions.pdf), in the USA.) You can partially circumvent that by legally separating the land into an outer shell and inner sanctum. Imagine a grid, 11 miles by 11 miles (121 square miles). There are 640 acres per square mile, so this is only 77,440 acres; nowhere near implausible given the sizes of the top 10 ranches above. Now take the center square mile, which is at least 5 miles from any edge, and legally make that a *different* property; even if the same person owns it. So it is the inner sanctum and the rest of the property forms a shell around it. To my knowledge you are not required to provide any means of public access to that inner property. Because it is a legally distinct piece of property, it requires a separate warrant to search it. You personally can access it via private road passing through the shell, but that does not have to be accessible to police or anybody else without a warrant. Your inner sanctum can be surrounded by tall stone barricades and heavy steel doors; so they can't see anything going on in there. From five miles away, it would be difficult for police to claim exigent circumstances exist requiring them to search that inner sanctum. Simply being suspicious of what might be going on there is not a legal reason to search private property. For the span of 50 years or so, this should easily protect you from interference, if you are not using or transporting any illicit substances, and you are not creating a workplace, manufactory, or child care environment subject to government regulation. (If any of that **is** true, then the government has an excuse to search your premises; but try to put such places in the 'shell' area.) ### addressing commentary: You do want to fence the entire property with an opaque fencing system; and probably in a few concentric rings to prevent observation from the ground using telescopes. So in the outermost layer, just a tall brick wall. Then perhaps tall trees for a quarter mile, then a black steel wall. Yes, cops can still fly over or helicopter in. But they would need a *reason* to do that, some evidence of criminality; and they would be met by very expensive lawyers in very expensive suits demanding their warrants. These would likely be connected to the most prestigious law firms in the State and in the USA, people that have the private cell phone numbers of the Governor and Senators on speed dial. Getting a ranch outside the jurisdiction of any city or town gets rid of interference by local cops or law enforcement, so you only need to worry about State and National level law enforcement. Steering clear of the tiniest hint of dealing in drugs, humans, prostitution, porn, weapons or money laundering denies law enforcement any good excuses to search your premises. Make up a benign cover: Lair guy obviously has money, so he is an eccentric billionaire, a brilliant financial wizard that is using his money to protect himself from well-funded corporate spies, assassins and nut jobs, and working on robotic and engineering inventions. It would not be hard to fake thousands of Internet death threats. And NO, he is not going to show you what he is doing or how he is doing it, those are trade secrets he is entitled to KEEP secret and in the USA we are not required to just trust law enforcement to keep our secrets. He can claim that just the sight of his robots or engineering efforts could cost him many millions of dollars, a single cell phone picture could be used by his competitors. To get a search warrant law enforcement must show plausible reason for a judge to believe a crime is being committed on the property and that a search will produce evidence of it. Just "he won't tell us what he is doing there" is not enough; at least not enough for somebody with the most prestigious law firms on their side; and those law firms tend to have instant access and influence with the top of the political and law enforcement arenas. On top of that, the innermost compound can be nigh on impenetrable: If law enforcement does fly in, or drive in, they better bring a lot of dynamite and bulldozers to get through foot-thick steel doors and ten feet of steel and concrete walls. Which gives the white-shoe lawyers plenty of time to quash any trumped up search warrant. [Answer] # [Port Talbot Steelworks](https://en.wikipedia.org/wiki/Port_Talbot_Steelworks) If you take the place over and keep the steelworks running the government will practically pay you to have your HQ there. Nobody will notice any heavy industrial equipment coming and going, nor any weird noises you might make. Your power supply is unlimited, I doubt you'd cause a spike in standard consumption no matter what you do. The facility will also have a selection of no-go areas, mostly because they're somewhere above the melting point of iron, but your 200sqm requirement would probably go completely unnoticed. **Historical note:** At the time of writing this answer the Port Talbot Steelworks was under threat of closure. The government was involved in negotiations for a sale of the plant to allow it to be kept open. This deal is currently on hold as a result of Brexit and as of late 2018 is still pending completion. If you want a steel plant, it's still up for grabs. [Answer] ## Hiding in plain sight Others have mentioned hiding in plain sight by placing your HQ below a legit factory or office building. This is a good idea, in that no one will notice your power and water consumption. But there are problems with these "plain sight" locations. For example, most cities require permits to alter the floor plans of the building. These permits, and all of the architectural drawings related to alterations, are kept on file as public records. In [Los Angeles, California](http://ladbsdoc.lacity.org/idispublic/) and other cities, you can search by address and pull up scans of these drawings. Sure, you can hire shady crews to hide floors or dig new sub-basements that aren't permitted/documented. But this is a risk. If, for example, a new sewer line or a new subway line project begins, they may hit your undocumented sub-basement level. Or someone doing a raid on the building for other reasons might pull up all the documents, discover there are 2+ basements on record, and demand to see those levels. "But there's only the one basement level?" And suddenly you're discovered. ## Underground So instead, buy an [abandoned missile silo](http://www.realclearlife.com/history/abandoned-atlas-f-missile-silo-sale-lewis-new-york-3-million). These are hardened, protected structures. There are several on the market in the USA. At least a few have been converted to private residences. List yours as a private dwelling on any deeds / permits. And then you're safe and secure. Sure, you'll need to invest in security measures. But the structure is unlikely to be penetrated by any non-military forces. ## At Sea Or buy a [container ship](https://en.wikipedia.org/wiki/Container_ship). Build your industrial machinery in modular format as cargo pods. Now your HQ is mobile, can hide in international waters, can travel wherever your evil plots require, and is hidden from satellite surveillance as well as pesky legal jurisdiction. Using solar panels and salt water filtration systems, you can have nearly unlimited water and power. Your biggest issue will be diesel for the ship engines. [Answer] Just buy an office building right in the center of a large city. Put your secret stuff in the basement while you put a legitimate business on top. As long as your front business stays clear of any suspicious activity, you will never have any thorough inspections by law enforcement. Even workplace safety inspections will focus on the rooms where the official employees are working and won't even look at the basement. If you want to be even more safe, get a building with two basement levels. Put your secret stuff in the second basement and conceal the entrance. Make sure anything one would expect to find in an office building can be found in the first basement level. Anyone who will come to inspect something won't have the plans of the building. They will just come to the front desk and ask: *"Please show us where you have your [electricity meter | water meter | sprinkler system]"*. If you want to be sure that even the original building plans won't incriminate you, give a bribe to whoever has these plans so they "lose" them or replace them with an "updated" version. But no matter how well you hide your base: Remember that your largest risk will always be a human leak. Make sure that any minions who work on your secret project are too loyal or too afraid to blabber... or just lock them up permanently inside your base. [Answer] A lot of people have suggested hiding in plain sight, something that is a good idea but I think we should go a little further. **Shoving it in the public's face** Create a large warehouse / open building. Place all necessary machinery inside. Make tons of independent films, using students, of said equipment. Promote the hell out of the films. Those sinister machines? Totally props. Open haunted houses during Halloween, and youth and addict outreach programs. Finally, place a bunch of homeless people outside the building. No-one will ever care about you, and will likely even forget you exist. As a bonus, all those students, addicts, and youths make for free labour. If you are feeling particularly evil, register yourself as a church to reap the tax benefits. After all, you are already active in the community anyways and the government is going to ignore you. [Answer] There is a hotel in Virginia (or West Virginia) that housed a secret bunker for years that was designed to function as a Continuity of Government (CoG) shelter for Congress. Until it was declassified and made public, the hotel was a fully functioning civillian hotel whose residents were none the wiser that the bunker existed. Maintence was achieved by claiming it was the TV repairman and then walking him discretely into the hidden portion. They used construction of an existing extension to hid the facility construction. There are numerous people who made residents in abandoned Nuclear Missile Silos in the United States. These facilites would easily fit your needs as they were built in part to be hidden to prevent detection and loss in nuclear war. They are pricy and the government would be aware of the sale. Walt Disney World has an entire underground city beneath its Magic Kingdom theme park. Due to the low water table of Florida, this facility was built as a level one, not a basement, and then landscaping made the access to the second story guest areas vitually unnoticable. Disney does offer tours, but restricts tour group access to areas that might be important. Old mines, especially if warning signs are properly displayed, could be re-enforced and secured. There are also companies that specialize in making secret doors that look like book shelves or what have you and even have a special lever to open the door. One such company even explained they're not all in the buisness of hiding secret rooms... one company ordered one to hide an unsightly janitor's closet in their lobby from public view. [Answer] You could try the [Hudson Valley](http://untappedcities.com/2014/09/23/27-historic-estates-to-visit-in-new-yorks-hudson-valley/) in New York state. They have lots of very large mansions near a natural water supply (Hudson River), that could be used not only for a water source, but electricity generation as well. And I know what you're going to say, "But how do I run hydroelectric generators without someone noticing them?" The answer to that is simple: Underground caves! The geology of the area lends itself well to natural cave formation, so you could probably find a mansion sitting right on top of one. The cave formation offers many natural advantages: 1. Preformed space for your secret lair. 2. Natural defenses such as rock to prevent accidental discovery. 3. Being underground provides a natural source of cooling and sound insulation for all of your computer gear and nefarious machinery. Unfortunately, there's some disadvantages: 1. Bats like underground caves. Everyone knows that bats harbor tons of [diseases](http://www.cdc.gov/features/bats/index.html). But, if you play your cards right, you can spin the whole bat thing to your advantage! Think of it, lots of people have an unreasonable fear of the animals. Perhaps you could adopt the bat as your evil symbol, injecting fear directly into the brain stems of your enemies! You could call yourself, Dr. Bat, or Batdude, or something like that. Your lair could be referred to ominously as the Man Cave, or Bat Hideout, or something along those lines. Furthermore, living in an isolated mansion, deep in the Hudson Valley, people aren't likely to come around asking for candy at Halloween, selling vacuums, etc. And if there's lights on late at night, or weird noises, well, eccentric billionaires just do things a little differently. People will naturally ignore odd goings ons. Strange deliveries of heavy equipment? Probably just some new business venture, no biggie. I don't know why, but I just think this model of secret lair just has something going for it. [Answer] **Outside the reach of any government** Try **[Sealand](https://en.wikipedia.org/wiki/Principality_of_Sealand)** At ~3800m^2 you have plenty of room to expand on your nefarious plans. Its got power (its currently a data center, I believe) and the miles of ocean keep nosy ramblers away. The best part is: because of a [inanely boring territorial waters dispute](https://en.wikipedia.org/wiki/Principality_of_Sealand#Legal_status) involving betrayal, courts, coastguards, jetskis, mercenaries, helicopters, hostages and rebel factions (How is this not a movie already?) it is a structure in British territorial waters, over which Britain has no legal jurisdiction. Anyone comes poking around, just tell them to get lost. Buy it in a private sale (its been up for sale several times now) and set up your nefarious evil lair in comfort, close enough to moon the people of felixstowe. [Answer] # In an Old Public Institutional Campus I am primarily thinking a university, but a large hospital complex, or a sprawl of governmental bureaucratic back-office would work similarly. What you get from these old, large, institutions: No-one knows what buildings/rooms they have. They are older than computerized record keeping. Many many records are already lost, or incorrect. Plenty of walls and doors not shown on any maps, whole buildings that were never properly authorized. Sealed WW2 bunkers. They have their own large facilities and planning departments -- any construction works will be going through them, even if it is externally mandated. So if you plant someone on the inside there you get all the heads up of major works you need, and can likely fillerbuster them for months or years by having your infiltrator pull up roadblocks and internal bureaucracy/politics. They have: * huge daily movement of people -- to hide your comings and goings in the crowd * vast use of water and power -- so your own will vanish in the noise * lots of materials coming in and out every day, including "wacky science stuff" -- so your own imports will go unnoticed, not to mention the opportunities to "redirect" some of there resources. * very unusual electromagnetic radiation signatures -- again concealing your own machinery Further to this, they often have special interactions with the law, such as being directly referred to in acts of parliament dating from their creation. This leaves them immune to many modern laws that should cover them, but fail to do so, because they are not technically the kind of organization one would expect (E.g. they may be a not-for-profit organization, but not bound by the Incorporations Act). And they may have specific and unusual laws giving them unexpected powers many other locations do not enjoy. Such as the [Greek "University Asylum Law"](https://hydra.hull.ac.uk/resources/hull:8399) which (formerly) forbid police, fire-brigade or army from entering university grounds, without express permission. Finally: you can social engineer you way into them. Because they are so large, and have so many things going on, no-one truely knows what is meant to be happening -- the left-hand does not know what the right is doing. As an undergrad, I would on occasion when finding nowhere quiet to study, walk up to a department office, sigh and say *"Someone has locked tutorial room 2.21b again. Can I have the key? thanks."* Invariably it would be handed over without question as to what right I had to be there. Doing this on a grand scale involves identifying an unused (or underused) building, turning up with a bunch of folk in safety vests, and carrying clip-boards, and moving in your stuff while changing the locks. If any one questions you, you just say > > "Of-course, how have you not heard? This is now the new National Center of Excellence in High-energy Mutagenic Agriculture. You need to contact ..." > (flicks through clipboard) > "... the senior deputy vice-rector for national collaborations. Here is her number." > (reads out a number that goes to one of your people who is ready to shut-down inquiries.) > > > [Answer] The biggest question is "How often do you need to go in an out?" If we look into the numerous fictional and real life secret facilities, there are few basic options: 1. The middle of nowhere; 2. Hidden in a developed area; 3. Hidden within a legitimate facility. "The middle of nowhere" has some advantages, but then you would need to provide electricity, and this would be difficult to hide. You hope would be that nobody is coming looking in that area. And the most difficult part would be traveling to and from this facility. Unless you are a Superman, this trip should take days, and other people might spot you. "Hidden in a developed area" is better in many aspects (providing that your secret room is hidden well). You basically find a place that nobody is thinking of owning, like abandoned subway tunnel or basement nobody knows exists, secretly hook up to the utilities and make this place as comfortable as you need. The most obvious advantages are that you would have electricity and water, and maybe even cable TV. Also your trips in and out would be short, and you can move your stuff out on a short notice. Drawbacks, however, are also significant. The city, or utilities company, or owners of nearby places may suddenly discover that your lair. People might see you coming up and down a manhole, or disappearing behind a secret door. "Hidden in a legitimate facility" is by far the most realistic way to achieve what you want. You obtain the rights to a land/building and hide your facility inside of it, or underneath it. You will have all the utilities without suspicion (but you have to pay for it). If your bunker is hidden well, any "regular" searches of your front facility would come up with nothing. Depending on scale of your operations, you may choose either "dormant", or "active" front. A dormant front would be a house/business that stays empty/closed/shuttered most of the time. You can come in an out without raising any suspicion, but empty places may attract attention of petty criminals. For an active front, you will have your associates occupy the "front" and maintain an illusion of some ordinary business. This way you can conduct any kind of operations inside your secret facility, and move in an out any equipment, or people. [Answer] Buy a section of an old atom bomb testing facility with only safe amounts of radioactivity left. Make sure it has several ghost towns, maybe even an old military base. You could even get the government to sponsor you to clean it up. Put up plenty of Danger signs. If anyone wants to come in, give them a radioactivity sensor and scare them to death. Drive in and out wearing ABC suits and helmets. Build your stuff underneath and inside the ghost towns. [Answer] Do what the [government](http://en.wikipedia.org/wiki/The_Greenbrier) did, buy a hotel, the more remote or resort like the better, build an addition on the hotel, maybe a new wing or kennel, at the same time (at night) build a secret bunker underneath it. All the moving and excavation just gets lost in the normal legitimate construction, they had to dig to build a stable foundation anyway. This is actually a pretty common way to build bunkers. Once it is completed it is easy to hide people coming and going among the normal guests, deliveries, staff, ect. [Answer] **In the mountains** You can dig a secret cave in the mountains an place a "decoy" chalet not far from the actual lair. You can justify the power and water need with the chalet and you can post some undercover guards/soldiers (make them look like mere tourists) to spot incoming potential threats in the said chalet. Make sure that the entrance to the lair is a secret entrance though. You can use snow to make water if you want and a generator or solar panels for electricity, all being justified by the chalet. Plus, anybody too curious about your lair can be disposed of easily in the middle of the mountains. You can also hide some defence systems (like turrets, CCTVs or move sensors) under fake rocks if you're really worried about a potential attack. [Answer] The simplest way: * middle of nowhere * believable cover * underground complex, where you can squeeze those "200m" So for example a holiday dacha (second home) with nice but fully taken care of garden. And it has an underground garage with a trap door... If you are not lone hero/antihero, but a member of a secret organization, then a house owned by some old couple, who sometimes rent rooms, looks even more innocent. [Answer] Can you move your equipment by boat without being obvious? I spent about a week in a building in the Amazon jungle. We had a flush toilet. With seven people cooking,bathing, flushing toilets, and getting enough to drink, we did not run out of filtered rainwater. If we **had** run dry, we could have filtered water from the river. Four solar panels on the roof kept a battery bank charged, and the big food freezer and all the lights and electronics did not drain them overnight. Took hours to get there from the nearest village and we saw only two or three houses on the way. [Answer] All the in plain site answers have the same problem--once they spot YOU, you are done for--they will follow you via satellite, video & aircraft and if they want you bad enough, your lair will be found. I'd say the ONLY safe place might be underwater--if you could make it to the sea I don't think it would be as easy to follow you. Anti-sonar tech might make you amazingly hard to find if you are deep enough, the ocean is too big to scour every inch. The only other place I could see is if you had enough money and had a legitimate front you might be able to buy a section of land from one of the many governments around the world. I'm a little surprised nobody has done that yet--just buy a small city-state. You could contract with that government for military defense as well which might be enough deterrent to keep other governments from wiping you out. [Answer] ## Inside a Dam You build it inside the dam during construction. Earthen dams are the best, since your hollowing is displacing less strength, and it's easier to make up that strength with steel or concrete. It helps if one of your companies gets the contract to operate the dam. Pro tip though: Make sure you maintain the dam tip-top. If you get into a situation where the dam is having serious trouble... and that gets a lot of government attention... it makes concealment a *lot* harder. *You know, like the main spillway getting undercut by your expansion work, and having to use the emergency spillway and evacuate Oroville.* By the way, you're gonna wanna win the repair contract. Don't try to make a couple bucks highballing the deal and have Kiewit undercut you by a measly $1.4 million, and then have to spend most of your fortune to buy Kiewit. *Ugh.* Water is not a problem obviously. Electricity isn't either obviously, you can tap the main turbines. Or have a small backup turbine, they might notice your turbine output in the diversion tunnel, so just leak it into the subsurface of the dam. There'll be a green spot there, nobody will care. Also you have air access via floatplanes, make them submersible so you can use a submarine base concealed by the powerplant intake structure. Works great. [Answer] Where to hide 200 m² of a low noise, low dirt, low profile operation for 30 years? Let's go through some possibilities. # In plain sight 200 square meters seems like a lot, but it is pretty much a rectangle of 20 x 10 m. Or in other words: a typical large home with a small garden. So, as it is not generating any extraordinary products, the first solution is easy: Hide it in plain sight. Some of the options you should consider, as long as the operation itself can run a very low profile and the paper trail between HQ and operations is nonexistant. Because there are laws that prevent random searches of private property without a warrent, these work. Water and power even come with them! ## Office Tower Renting office space for long term or even buying it might not be cheap, but place a name like "X&Y Consultants" on the door, hire a receptionist and have them take calls, telling the people "Sorry, there are no free spaces in the schedule of Mister X or Y for the next year... shall I put you on the waiting list?" or something. Anyway, who but the IRS checks consultant companies anyway? Just pay the tax and you are totally hidden in plain sight! ## Appartment Complex When we could have an office, why not just rent or buy some flats adjacent to each other in a nondescript appartment building and removing the walls between them, adding extra stairs and such till you are at 200m²? Nobody knows their neighbor in those buildings. Mount something in front of the windows to simulate people living there, never bother to change the nameplates on the bells and nobody will even notice. Just pay the bills from different funds and if somebody asks you who those immaginary neighbors are, say you think they all work odd shifts or something. In the run down "Banlieus" nobody cares who is their neighbor anyways, unless they can be blamed for something. ## Fancy Skyscraper Anonymity Well, maybe we want it more fancy than owning a ton of run down flats. Why not take the same idea and go fancy? Rent a penthouse or floor in an appartment building - and pay the porter extra to not be on the name plate. You are just that excentric guy living on the 10th floor, 200m² with perfect view on the Hudson or something. Expensive, but as long as you pay your bills, nobody will be the wiser. ## It's all legit! What kind of equipment does your HQ need? Often times, equipment can be used for multiple purposes at once, so find a solution how it can be done with what is in your lair! Even if they search, they shall not find anything but what they expect. * A server farm? Easy, just BE a server farm, just one quite a bit larger with space dedicated for your HQ. * You need a war room with spinning globe, huge TV screen and a fancy collection on the walls? Become a broker and have all this fancy equipment double as your screen for stock exchanges and show off how rich you are! * So many different equipment that you can't keep track of it and so many goodies you want to stock? Be the R&D (in your own company, run by a straw puppet)! Nobody expects the R&D to plot world domination. It's allways the boss of the company, and those never work in R&D, right? # False Facade While we just had an official adress earlier, used to hide the operation, you might want some kind of a mix between Plain sight facade and actually hiding the equipment behind a false wall or space. We don't need to start precautions to hide our paper trail then, even welcoming a search of the open parts of the HQ. We need more than 200 m² then though - but power and water can be siphoned from the facade. ## Suburbia In the suburbs, houses can get large. Buying place where gardens are long and wide enough allows you to constuct your secret lair under the floorboards of a normal family life! Construction is a bit tricky, but it is not too uncommon to live in one space for a long time. Just hide the entrance to your lare under your model train landscape, and nobody is the wiser. Just appease the neighbors with an occasional BBQ and they will even vouch that you are clearly not Mister X, even if you plan world domination under the floor. ## Industry Mogul Money is not an issiue? Let's go BIG! I mean not like 500m², go fully large! Not just a fancy house in the suburbs, buy a whole factory, including workforce and produce whatever it produced all the time anyway. Schedule some expansion to the factory complex, and build your secret lair into the floor, then have the plans on file altered. That cellar? Was never built. Every morning the workers come, do their buisiness, secretly funding your plans, go... and under the floor? You plot and tinker on your secret world domination devices. ## Farmerboy Famland is large, cheap, out of the towns... and farmers are crazy anyway, don't you think? In many rural areas people know each other well, and they know when Tom the sherrif comes for a coffee on his tour. Or when Mike Policeman has his patrol on the Highway. Again, keep up the facade well and nobody will be the wiser. And you can hide all the rubble and earth from digging your lair under the barn on or between the fields. # Out in the Blue We can hide in plain sight with easy access, we can errect a false facade to hide better. But then again, we can go where people don't thread likely. ## Parkie Can you have construction debris disappear with enough money? National park for the Rescue! Make sure to hide the entrance well, and the rangers will have a very hard time to accidently stumble over your lair - and since construction is prohimited in a national park usually, nobody will even think about looking for an underground construction there. Even better, if you can bribe the rangers to look the other way when you haul in a new batch of equipment. You better get autonomous in power and water means though, as you will have to drill your own water supply and sewage dump, and also some means of getting power. Geothermic power might be a solution. ## Afloat What happens with an oil rig after it has run out of oil? Usually, they are deconstructed. But some are kept for other reasons - like an excentric millionair who might turn it into his private resort maybe? So, with enough money, an empty rig is available. What's even better is, some are out of the 12/24 miles zone of any country, and thus in [international waters](https://en.wikipedia.org/wiki/International_waters). What does that mean? You are out of jurisdiction of the country! Yes, that's right: [Police and FBI](http://people.howstuffworks.com/cruise-ship-law1.htm) can't go and arrest you on your oilrig out on the ocean. Why? Because a floating offshore oilrig is in the eyes of the law a ship (unlike one affixed to the seabed, which is an artificial island), and thus it is in the coutnry of the flag it flies. Just fly the flag of a country that is very unlikely to give a damn and your HQ is safe, even if they can see you building up a world domination device. Even better: if they try to stop you it is an act of agression against a foreign state without a declaration of war. If you have mounts to the seabed and are further away than 200 sea miles from the shore, you are an artificial island wich belongs to the state that ordered its errection, which means it is part of the country you choose. For closer to the shore installations, it gets a bit more tricky, as construction of artificial islands there makes them part of the closest country (see [Artificial Islands in the Law of the Sea](http://www.blue21.nl/wp-content/uploads/2015/10/Artificial-Islands-in-The-Law-of-the-Sea.pdf)). Water purification can be powered with wind and tidal power, you just need to schedule monthly supply missions per helicoper. [Answer] **A disused mine** Some of the answers here may overlook various safety inspectors or intrepid workers in a coverup business. The advantages of using an already dug mine: * Not visible by satelite * No visible heat signal from aircraft * No external foot traffic * Government grants available if you do choose to reopen it (though this may not be the best option) * Depending on the mine there may already be provisions to move your heavy machinery below surface (dedicated lift) * Ample surface area * Facilities (water and electricity) can be installed as you wish. However the real advantage here lies with the danger associated with mining. Say there's a government inspector that wants to have a look at your operation- fine, let him explore everywhere except shaft C, which is flooded/ unstable/ collapsed and retired from operations. If you choose to open the mine for business you could realistically limit employees from venturing into the shaft C by using any of the afore mentioned techniques. What would be particularly effective would be if you could flood a part of the mine at will, opening it only for your access, though I can't imagine this would be a structurally viable option. What might be a better course of action would be to buy the mine for a handsom price (based on current estimates of remaining coal/gold/uranium) then claim that the resources are considerably more depleted than thought. In this instance you have a cover story to justify initial investment and moving in machinery, installing/ renovating a heavy duty lift and facilities, but you have no need to send workers in, as it's no longer cost effective to dig. You could even potentially justify hiring a few low paid security guards to keep visitors away whilst protecting your land. You yourself (if you want to remain unknown to said guards) could enter under the guise of a structural engineer carrying out routine checks on the integrity of the mine. [Answer] If money is not an issue than a remote Island can be an option, all to yourself with perfectly set up recycling facilities to deal with wastes and no check ups by local authorities. As for electricity solar panels or any other means can be set up [Answer] Build it at Disney World...errr evil overlord world! Disney runs that area. They have full control of the local politics, policing, and management. They can bury almost anything there under a wall of employment contracts, service bills, and purchasing deals. Bits and pieces of stuff can be inserted into legit agreements, almost anything can be bought under the guise of research for a new concept. About the only thing you couldn't do is nuclear power/radioactive material refining. The US govtracks stuff needed for that much too closely, but almost anything else could be allowed and built in secret. There are entire departments at Disney that are blacked off from the rest under the guise of preventing corporate espionage. An evil base would fit right in. Heck, one could argue that Disney is itself an evil corp manipulating the US right now! [Answer] Here's a low-tech option. Buy a farm, maybe wheat or dairy. Build a new barn (or refurbish an old one) to cover construction of your underground facility. Add water wheels on the nearby river for hydroelectric power (get your water there also). With a farm you have an excuse for trucks coming and going. Nobody inspects farms, especially if you advertise yourself as organic, with no pesticides or hormones. To casual visitors, your farm will look genuine because it is. If your "hobby" involves biology, so much the better, you can hide unusual creatures in a herd--just make sure they don't escape. Your nearest neighbors may be miles away, so odd noises and sights won't be noticed. If you have "special" visitors who can't be seen in town, they can travel cross-country or use small aircraft. Larger farms often have airstrips, so yours won't arouse suspicion. Keep your employees out of trouble, maintain a plausible level of output, protect your property discreetly, and you should be able to indulge your hobby as long as you like. [Answer] A combination of in plain sight and invisible. A novel I read some time ago talked about pretty much just that. The good guys/bad guys (the protagonist changed allegiance in the middle of the book) had a front company in New York with a legitimate office building. Their secret facility was located in an artificial cave several hundred feet below the city, with an elevator shaft running down from the office building. The story didn't explain how all this was constructed without anyone noticing, but one can imagine the rubble being carted out during the construction of the New York subway and water/sewage tunnels by just mixing it with the rubble from that construction work. What they used for water and energy supplies wasn't explicitly mentioned, but they appeared to have access to large quantities of natural gas so a small generator powered by that could work, the exhaust gasses vented into the subway tunnels where they'd rapidly disperse. Similarly, sewage could be mixed into the city sewers through hidden valves opening only after making sure there are no people in the sewers, or directly into the East River. If you can dig a large cavern like that unnoticed you can also dig a sewage tunnel to some way outside the city of course, making detection even less likely. If you want more secrecy, James Bond movies have several secret lairs, ranging from underwater cities to caverns in extinct volcanoes with covers over the crater that can be made to swing out to launch rockets from them. All of those of course eventually exposed by Bond, but secret for a long time until our hero tracks them down through mistakes by the minions of an overly confident evil genius (and you're of course smarter than Mr. Blofeld, right?). Then there are the existing conspiracy theories about secret CIA and Nazi bases under the Antarctic ice cap. Exploiting those to create a real base there, then reinforcing those conspiracy theories to ensure that anyone talking about your base gets branded a conspiracy theorist and never taken seriously could very well work as well (this was in fact how the US government kept secret what really goes on at Groom Lake AB for decades, the conspiracy theories about aliens at the facility made anyone talking about secret research there appear laughable at best). [Answer] **Underwater** For all the same reasons as the [Sealand answer](https://worldbuilding.stackexchange.com/a/86315/37082), an underwater lair far enough from the coast would be in international waters. What that one left out is that if anyone *did* spot you there, you could just shoot them and feed them to the local wildlife. What's anybody going to do about it? The benefits of having it *under* the water is that you can install a room to filter the water to make it drinkable, and simultaneously use this room to both power itself and the rest of your base. The weight of the water on the base is enough to get the gears moving, and once you've done that, it's all - literally - downhill from there. ]
[Question] [ I [Previously asked](https://worldbuilding.stackexchange.com/questions/98073/how-can-my-ancient-roman-civilization-develop-effective-steam-power-for-use-in-s) if the Romans could have built a steam engine to power a ship, which received a number of answers perhaps best summarised as “probably not but…”. Assuming the Romans couldn’t have come up with the idea on their own, suppose that they had discovered a working example of a simple steam engine, what then? (Preserved by a previous civilization or whatever out of scope hand waved reason). Assume they also had simple visual operating instructions. [Answer] **If a civilization finds an example of advanced technology, can they learn to duplicate the technology?** You have two variables: * The current technological state of the civilization. Call this "A." * The technological difference between the civilization and the example. Call this "B." Therefore... * The earlier "A" is, the more likely the answer is "No." * The greater "B" is, the more likely the answer is "No." (This is a necessary axiom of [Clarkian Magic](https://en.wikipedia.org/wiki/Clarke%27s_three_laws).) * As "A" advances, "B" can grow wider and the answer can still be a "Yes." **What is our year point of reference?** The Romans were technological marvels, but most of their advancement was in structural engineering. Had your example technology been anything involving electricity my instant answer would have been "absolutely not." However, the Roman empire encompassed a large amount of time and a large amount of technological innovation. Just as my grandmother during her lifetime saw the horse-and-buggy and steam ships as the pinnacle of transportation technology give way to walking on the moon and air flight so common people don't dress up for it any more, the Romans shifted from their early years ("absolutely not") to 300ish AD when the answer becomes "possibly, maybe even probably." An important date is 1 AD. That's when [Hero of Alexandria created the Aeolipile](https://en.wikipedia.org/wiki/Aeolipile). The Aeolipile was, basically, the first steam turbine. At this point they may not have had the other technological know-how to build a fully functioning 1800s steam engine... but they would have played with it for a while and, maybe, would have concluded, "you know, that looks an awful lot like a really complicated Aeolipile." **So far, I'm convinced that Romans from at least, say, 50 A.D. would have understood what they were looking at (after enough examination & experimentation) just as we have the ability to understand string theory without having the slightest idea how to prove it.** That leaves the question, could they duplicate it? The components of a steam engine are improved with milling, but do not require milling. They can all be cast. The Romans knew how to do this, so they could build the shape of everything they need. That leaves metallurgical strength. And that's where the last point I can make comes into play. **The Romans knew how to think** The ancient Romans knew how to figure things out. It would take time, because they're basically stuck with empirical research, but they could do it. Now the answer is "Yes, given enough time." **How much time do you need between when they found the engine and when you need them to duplicate the engine?** The following are all gut instinct and open to vociferous argument, but... If the answer is found in 50 A.D., needed by 300 A.D., I'm willing to go out on a limb and say "Yes." If the answer is found in 50 A.D., needed by 100 A.D., it's "very unlikely." If the answer is found in 50 B.C., needed by anything less than 200 A.D., it's "probably no." If the answer is found before 50 B.C., the answer is "impossible." There's not enough technological understanding in the Roman Empire to be capable of comprehending what they're looking at and by the time the Aeliopile came into being the example would be deteriorated or lost. --- Some of the comments are wondering why the Romans would care to pursue steam engine technology. The OP hasn't told us the context of the future technology appearing in the past. If all that appeared was the engine, then it might be a hard sell unless someone was bright enough to think, "what if we hook this sucker up to a cart?" On the other hand, if what appeared was a working car... the Romans would be all over this technology considering the difficulties of their wide-spread empire. The real question is, what if it was a train engine? Something that needed tracks to be valuable? That's a whomping maybe because suddenly the infrastructure investment (laying rail) is enormous. **However, none of that is relevant as the OP didn't ask about it. It's the OP's problem to solve. If he hasn't, it's another question and not a valid answer to this one.** --- A number of commenters have expressed disbelief that reverse engineering can bring substantial value to the technological innovation process. Their premise is that the technologies didn't develop for a millennia or more on their own, which assumes they couldn't have developed in 200-300 years with a working example to experiment with or to motivate them. Such commenters have no experience with reverse engineering. I do. Knowing that something is possible and you only need to duplicate it is much, much, much more powerful than not knowing something is possible and waiting around for the combination of imagination and scientific development to merge. The simple truth is if the Romans were shown with irrefutable proof the value of a working steam engine, they wouldn't have one or two guys out there tinkering around with a vague idea (which is why it took millennia naturally). They'd have thousands and more people dedicated to realizing the military advantage. (Unless as previously indicated you want to choose that they don't see the value, in which case this is all a moot conversation. You won't invent what you don't care about.) Some people like to think that innovation is somehow a fixed process, that it can't happen any faster than it did, but our own recent history in computer development has proven that wrong time and time again. ***You need not understand why something works to duplicate it.*** To conclude with an example, I wonder if some believe the specifications of an antique steam engine are as difficult to achieve as a 2017 combustion engine. Obviously, the metals and precision needed for a 2017 engine could not be duplicated by the romans during their time. But that isn't what was asked for. When I once read *The Grapes of Wrath* I noted a moment in the story when the family had to repair their engine. They'd lost compression, so they wrapped copper wire around the piston, shoved it back into the chamber, and off they went. I wondered about that and so asked my grandmother, who said things like that did, indeed, happen. *That's an awful lot of imprecision to still have a working and useful engine.* If you still want to believe the Romans couldn't reverse engineer something as simple as a steam engine (with operating documents!) under the conditions I've specified, by all means, downvote my answer. I won't feel bad. [Answer] What's a "steam engine"? A steam engine is an external combustion engine which uses steam as the working fluid. So we have: * Newcomen's original [atmospheric engine](https://en.wikipedia.org/wiki/Newcomen_atmospheric_engine)? The Romans (or rather the Greek engineers on which the empire depended) could have copied it, most likely; *using* it is another question -- it's a very very inefficient engine, which was useful only to pump water out of coal mines, eating lots of locally extracted coal in the process. The Romans did not have coal mines... * An early separate-condenser [Watt engine](https://en.wikipedia.org/wiki/Watt_steam_engine)? Copying it would have been either impossible or very very difficult; using it may have been possible. This type of engine is much more efficient than Newcomen's contraption, but it uses axles and bearings which may or may not be possible to make with late Greco-Roman technology. Anyway, this is the only type of engine which is both useful and not light-years beyond late Greco-Roman technology. At least they could understand what they couldn't make and work to find a solution. * One of the most perfect mid-19th century [Corliss engines](https://en.wikipedia.org/wiki/Corliss_steam_engine), some of which *are still operational* in the early 21st century? No way could the late Antiquity copy it. They wouldn't even have had the ability *to express the dimensions* of the pieces accurately enough, much less to make the spherical valves. Not to mention that Corliss engines operate at pressures high enough to blow up any kind of sealed vessels that an artisan could dream of in Roman times. * A middle-to-late 19th century locomotive engine? I hope they don't even try. Locomotive engines operate under tight space constraints, so that in order to achieve acceptable efficiency "ordinary" locomotive engines worked with pressures *starting* at 12 atm up to about 20 atm, while ["high-pressure" locomotive](https://en.wikipedia.org/wiki/High-pressure_steam_locomotive) engines [reached about 100 atm](https://en.wikipedia.org/wiki/LMS_6399_Fury). * A late 19th century nautical triple-expansion engine, as used, for example, on Nansen's [*Fram*](https://en.wikipedia.org/wiki/Fram)? No way unless by magic. The physics and engineering in a late 19th century nautical steam engine are way beyond what was understandable by late Antiquity engineers. * An early 20th century naval steam turbine engine? Not even with magic. [Answer] Not in a way that would bring about the industrial revolution. Steam engines depended on advances in metallurgy beyond what the Romans had. Specifically steam engines require the consistent production of steel. While the Romans could produce steel it was time intensive and of inconsistent quality. The predictable failure of steel is important when you are constructing pressure vessels to contain high pressure steam. Technically they could have produced simple steam engines like the [Newcomen Atmospheric Engine](https://en.wikipedia.org/wiki/Newcomen_atmospheric_engine) that operated at a maximum of 2 psi (0.14 bar) with a speed of 12 strokes per minute. This machine was revolutionary at pumping water out of mines but is not the steam engine people think of when they thing of the industrial age. Having a need for steel of consistent quality would probably lead to improved manufacturing techniques being discovered earlier than they otherwise would be but until those techniques are developed high pressure steam engines would be beyond the reach of the Romans. [Answer] Do not underestimate the technical ability of the Roman... They would have been able to understand the working principle (fire evaporates water, water vapor moves wheels). Then they would have tried to copy the design. Not having steel, they would have tried using other metals they had available (copper, bronze, cast iron, etc). With trial and error they would have come to some decent imitation. As reference, see: * their impressive building technique, achieved without knowing the concrete as we know it today and by a smart usage of available material * their ability to develop naval technologies after putting hands on Carthaginians ships (until then they were a land power, after that they started to rule on the sea, too) and putting some smart thinking into it. (credit @ Jeutnarg) [Answer] > > Necessity is the mother of invention. > > > Most of the innovation related points have been well covered in other answers. This includes the Aeolipyle. Other mechanical concepts of converting circular motion into linear (screw) also existed. **Could** the Romans have **copied** the steam engine? Yes! **Would** the Romans have **copied** the steam engine? Maybe! **Could/Would** the Romans have **used** the steam engine? NO! Technology isn't developed because it can be, it is developed because it must be. There are several forces at work here. Someone needs to fund the research and development. Someone needs to invest a lot of money and resources towards the critical initial growth of the technology. There needs to be sufficient scope for returns on investment. If the new technology is disruptive, then there will also be opposition from stakeholders in the existing technology that will be affected. If the new technology is extremely prolific and could affect the balance of political power, then politics will play a part as well. The OP has not specified a date/period so lets assume the Roman empire is already established. The Romans are spread thin and find it difficult to simultaneously control their entire empire with insurgency issues everywhere. Can the steam engine aid them in consolidating their empire? Or will the emergence of a steam engine ruin existing economy and consequently their grip on the empire? Even worse, the steam engine could well fall in the hands of rebellious entities in the empire and serve as force multiplier, which once again leads to the fall of the Roman empire. In view of potentially counter productive influence of steam engine technology, the Romans may choose not to build it. In the modern era, we have a similar situation with regards to alternative energy sources. The powerful transportation and energy lobby supporting conventional sources like gas and coal are opposing alternatives. Could we develop energy efficient solar cells, wind turbines, etc? Sure! But are we? Well, kinda, to the extent that it is being allowed to and not more. What will happen to the livelihoods of millions of workers directly and indirectly affected by the gas and coal industry? What will happen to their votes? Will availability of cheap energy alter the balance of geo-political power? -- An entirely different point is that of technology innovation date. Damascus steel existed centuries ago, but last I checked, we can still not replicate it. This brings to light the point of challenge in fabrication and know-how about the fabrication process. Will it may not apply specifically to steam engine (too simple), it is conceptually possible that humans couple of thousand years from now (working with nano-tubes, micro-robots and quantum computers), may not be able to copy a steam engine! and even if they somehow managed to do so, will not use it for sure! [Answer] # Knowing that something is possible is a huge headstart It's extremely common in the modern market for someone to come up with a new exciting product that opens up a whole new field (iPod, iPhone, Ford's Model T, IBM PCs, and so on) to be copied in short order. Competitors will quickly acquire copies of the invention then tweak it to make it their own. This process of copying is so widespread that patents exist to give the inventor a little breathing room to make some money before facing strong competition. A significant portion of the time spent in the process of invention is finding all the things that *don't* work. Handing the inventive, industrious and power hungry Romans a working example of a small steam engine that can do real work would light off a firestorm of investment. I trust that they're smart enough to realize that a machine that can do real work without muscle, whip or feed is a huge improvement. I think most people assume that the Romans would immediately jump straight to the enormous steam engines of mid-1800s Europe involving cast steel parts with highly precise machined faces and surfaces. I disagee. Given that the example they have is small, they will likely build small, low precision examples at first. Due to the imprecision, these machines won't be efficient. They won't have the theory to drive the math to get higher efficiency, at least not to start. # Materials & Precision Limitations A major limitation they will have is in materials, specifically their metals. While the Romans did work in iron, the ability required to achieve high quality steel at high speed, minimal cost and in large quantity wouldn't happen till the invention of the [Bessemer Process in 1855](https://en.wikipedia.org/wiki/Bessemer_process). (High quality was available before Bessemer but not cheaply or quickly. ) The Romans would have to use copper or bronze for their pressure vessels, limiting the pressures achievable. While not ideal, it just means their steam engines won't be as efficient as machines made from steel. Higher pressures might be achievable with thicker pressure vessel walls with the added cost in materials and increased difficulty in manufacture. They'll need to invent new means of measuring distance and diameter in order to get high precision. # Math A classic failing of the Roman numeric representation is the difficulty in doing multiplication. Inventing a new numerical system capable of zero and multiplication may be a bit much to ask. # Evolution Just like in the 1800s, steam engines will start with large static installations. As precision and materials improves, the steam engines can be made lighter and more mobile. Fitting them to ships, who naturally have huge capacity already, will be a natural choice. Smaller engines fitted to carts might be the early tractors. Not only will this steam engine give them a leg-up on the development of steam power but also screws, bolts and nuts. The invention of these fasteners will go on to revolutionize many other areas of Roman life. [Answer] Answer is, as most often is the case with "what if" questions, complicated. But in short it can be said: no problem understanding the theory, Replicating the machinery is a different matter. Simple steam engine was known in 1st Century AD - look up `aeolipyle` - and Romans had excellent understanding of parts of hydrodynamics - dams, pipes, aqueducts, pumps. So they would have no problems grasping the concept. But building a working engine requires more than just knowledge. I would say that it's possible to build very simple steam engine using Roman tech, but it would be very heavy and unreliable. As sphennings points out it requires high quality of metal alloy and a degree of precision manufacture not available to Roman tech base. I believe they would quickly found out that and after maybe several decades (on the fast end) to maybe a century at least (on the slow end) to be able to produce stable output. But the issue is not the tech, but the culture. Romans were uninterested in such things simply because they had enormous excess of power (slavery). Steam engine gained in popularity after it became light and small enough to build locomotive, for example, thus Romans would not have any use for their version. You would have to put this "discovery" in proper context (warship, i.e. ironclad maybe?). Industrial revolution in England began as a attempt to address the labor shortage that plagued (no pun intended) the Europe since.. well, the plague. Add wars (most notably the 100-years war, 30 Years War and 1000 Years Muslim Invasion) and the labor shortages are a fact of life until end of 19th century. In fact, the wars were mainly why the Europe was so poor for so long, as they sucked away lives needed to improve livelihood across the continent. What Roman need would a steam engine address? Most of the Roman trade is water-borne. Mediterranean is rather small sea, there is no economic nor political reason to invest huge capital to shorten the travel times by half - it sounds impressive until you realize that it means 3 days from Alexandria to rome instead of 7 or so (admit, I'm guessing here), and there are huge grain ships plying this route already. Sail ships, cheapest possible type. Rome-Londinium route? Again - current tech is enough and speed is not economically explainable. Raw materials needed to equip Roman legions and address needs of the population are there in sufficient numbers... The only way to improve average roman life is to increase supply of raw materials, but there is no way to do it. Last thing - for widespread use of steam engine supply of coal is needed. Wood is not good source of fuel. [Answer] Most answers speak of the difficulty in making working engines due to the limits of materials technology. What is perhaps more important is the understanding of *how* the engine is to be used. Since the Romans would be unlikely to replicate a high efficiency steam engine, what would remain would be a rather low efficiency static engine. This would still be useful for many purposes, and the Romans also understood such mechanisms as the crank and what we would recognize today as clockwork, so being able to tap the power of the engine would not be beyond them either. The true breakthrough would be to understand that the engine could be used to power more than one device, or to power a device over a prolonged period of time. I recall seeing a show which suggested the Romans used a water powered saw to cut stone at one quarry, with a waterwheel powering a crank which moved a reciprocating bronze saw. The evidence was a bit sketchy, but there was what appeared to be a flue for the waterway, and marks on some stones left in the quarry which could be interpreted as being from very precise and regular saw strokes. A stationary engine would allow any quarry operator to dress stone, not just the ones who happened to be near a flowing stream of water. If the number of slaves lugging wood for the engine were fewer than the number of slaves needs to cut the same amount of stone as a steam engine, then it is a net gain for the quarry owner. Another place where steam engines would make a huge difference would be textiles. A single steam engine can have its power transmitted to a multitude of looms or spinning machines, needing a far smaller number of slaves to radically increase the output of the Roman textile industry. All Romans could wear high quality cloth clothing, and Roman textiles could follow existing Roman trade routes (the Romans have left evidence of trade in India, for example) to dramatically increase the wealth of the Roman Empire. Massive increases in wealth due to trade would have many secondary and tertiary effects on the Roman economy and even Roman society (for example, the extreme divisions between the landless Plebes and landholder Optimates might have been bridged by a much larger "middle class" of merchants and traders dealing in mechanically produced products, and the skilled tradespeople needed to keep the machinery running. [![enter image description here](https://i.stack.imgur.com/XCZK8.jpg)](https://i.stack.imgur.com/XCZK8.jpg) *A factory floors in the age of steam. The Romans could have done this if they had a reliable power source* So even low power and low efficiency steam engines could make a huge difference in the Roman Empire. The real issue isn't in making the engines (it is clear they could do so, since they already had low power atmospheric engines), but rather recognizing the uses they could be put to, and most especially being able to recognize that powered machinery could displace a very large number of slaves yet create even more output (and thus wealth). As a related example, human slavery in Europe seems to have been ended with the introduction of the horse collar. A horse without a collar can pull a light cart with the same efficiency as 10 slaves, but *eats* as much as 10 slaves. A horse *with* a collar can pull much heavier carts, but still only eats as much as 10 slaves. Owning horses becomes much more profitable at that point. [![enter image description here](https://i.stack.imgur.com/VpDoe.jpg)](https://i.stack.imgur.com/VpDoe.jpg) *You end slavery by making it cheaper to do something without slaves* [Answer] As always, there a lot of commenters who have no idea how primitive first steam engines were. They demand bearings - but even first steam locomotives in 1830's used [oiled rags](https://en.wikipedia.org/wiki/Hot_box) for reducing friction. They demand steel - steel was not widely used before invention of Bessemer process and by that time there were ocean going steamships and extensive railways. They demand high pressure steam - but ocean going steamships like Great Eastern used only 5 psi. Some other points for simplicity I mentioned [here](https://worldbuilding.stackexchange.com/a/98090/30579). - To copy Newcomen age steam engine would be useless - river going steamboats of the beginning 19th century had boiler that weighted up to 1/6-1/4 of displacement, and Newcomen engine would require up to 5 times more steam. They would be unable to copy second half of 19th century engine - metal piston rings, steam injector, etc. Ideally Romans would get Newcomen engine with pickle pot condenser. That is almost as efficient as Watts engine, but as simple as steam engine would get(pickle pot doesn't need vacuum pump). Still, the lack of theory would impede them greatly. For example, they did not know square–cube law so they would not be able to scale their copy well. But I suppose a Roman engineer well above average could do it. [Answer] The original application of steam engines wasn't for transport or even for industry, it was as pumping engines. Steam engines are uniquely good for pumping. From there, they went into industry, and only a long time later became practical for transport. Industry did not start with steam engines. The Industrial Revolution was [originally powered by water](https://en.wikipedia.org/wiki/List_of_mills_in_Derbyshire), for [textile production](https://en.wikipedia.org/wiki/Spinning_jenny) amongst other things. This established the need for well-toleranced construction of machinery - bearings, drive belts, gearing, lubrication feeds, and all the features which you would expect in modern machinery. These modern production techniques enabled the construction of progressively better steam engines. The great advantage of steam engines was simply that factories no longer needed to be sited next to rivers with a good head of water - in every other respect they simply picked up the existing water-powered industrial infrastructure. Britain led the Industrial Revolution by being in the fortunate position of having plenty of money for investment (thanks to the slave trade), plenty of sites suitable for water power to start the industrialisation process, and then plenty of coal to power steam engines. It's interesting to compare the British Industrial Revolution with Roman technology. Romans were [profoundly skilled at water transportation](https://en.wikipedia.org/wiki/Roman_aqueduct), and this was not just used for drinking water but also for heavy industry, and even [water organs](https://en.wikipedia.org/wiki/Water_organ) which required precision construction. Like the British in the 18th century, there was no immediate need for them to move to using steam engines, because their need for industrial power was already being met by water. They clearly could have developed steam power, because all the technological requirements for the British Industrial Revolution were already there. What they lacked was a strong reason to do it. The Romans started mining in Britain and it continued from then, so by the 18th century miners needed pumps to drain water from ever-deeper mines. Without that need, the Romans would not have carried out the necessary development work to build a steam engine. And without the initial work on pumping applications, the work to turn it into a practical power source for industry would never have started. They almost certainly could not have worked with high-pressure steam, of course, because that requires higher levels of precision and metallurgy. But then again neither could 18th-century engineers like Newcomen, because all these technologies are mutual enablers and require advances in one to either stimulate or permit advances in another. Socially, the Romans also lacked a strong reason to move beyond piecework for cloth production and other similar work. Heavy industry like mining clearly benefits from industrial power sources to conveniently move things which are impractical for humans or draught animals. However the British Industrial Revolution was primarily driven by cloth production, and this involved mass-producing something which people were paid to do at home on a piecework basis. If you do not need to pay your workers - if you have a pool of slaves - then the economics of production are quite different. Of course you still need to feed them, so it still makes sense to use as few slaves as possible and make your processes efficient, but you do not have such a strong reason to invest in new technology. In fact, we know of [Hero of Alexandria's steam engine](https://en.wikipedia.org/wiki/History_of_the_steam_engine), so we know the Romans knew of the concept. What we also know is that they did not develop it further - and I've tried to give some reasons why that might be. So if they were shown another example of a steam engine, it seems likely that they would similarly say "that's interesting, but what can it do for me?" and keep going with water power and slave labour. [Answer] You *can* build a reliable engine with the alloys that the Romans could produce consistently, Bronze or Brass, and heavy castings but it will be more fuel intensive than is comfortable. The main problem with reproducing the beast will be in the fineness of measurements, getting a tight enough seal tolerance to not just spray steam from every seam. With a lot of patience, unlimited semiskilled labour and nigh limitless money you could hand grind the components to a fine enough fit but the expense would be staggering. That's the version where they have something to go with their steam engine to go off, like an actual blueprint, building a blueprint that was sufficiently detailed given roman era measuring equipment, no, just no. Honestly I'd expect that your Romans would actually blow up enough boilers trying to get the casting right to give it away as a bad joke, especially if they tried to match the materials, looks like Iron must be Iron... boom, rinse and repeat until they give it up. [Answer] The Romans had the Ctesibius pump which was a Greek invention. They improved it and gave it vertical stem type check valves. Not only that they had some degree of standardization for their plumbing systems which hints at the beginning of mass production. They had good quality modern looking bronze plug valves and decent lead pipes which were also standardized. In 97AD Sextus Julius Frontinus the Roman water commissioner wrote De Aquis Urbin Romae which described 15 standardized pipe sizes used throughout the empire. Plumbing found in Pompei suggests a high degree of quality control. All of leads me to think the Romans were a hairbreadth from developing steam power. A close look at the Ctesibius pump makes me think that if some relatively minor modifications were made and if it were placed on the boiler platform used by Heron to run his aeoliphile they could have had a workable Neucomen Atmospheric Steam Engine. So what might they use it on? Well perhaps nothing in Rome. But how about Lugdunum (modern day Lyons, France) a bristling prosperous commercial center on the Rhone-Saone River Network? That's where Marquis Claude de Jouffroy tested his Neucomen engine powered steamboat Pyroscaphe in 1783. How would that affect river commerce in the empire? [Answer] Problem in copying any XVIII+ technology is not in understanding the principles of the working; Romans and Magna Graecia "Philosophers" would understand it quite readily. Problem would be the required materials, which were simply unavailable at the time. Medieval Alchemists, while searching (in vain) for "Philosophical Stone", accumulated a enormous amount of knowledge about metallurgical processes which were used in the following ages. No way earlier smiths could have produced steel and other materials of sufficient quality to be used in efficient steam engines. [Answer] My answer will attemt to summerise the responses todate as I see them **The problems suggested** **The Romans didn’t have the machining skills such as milling** Whilst undoubtably a handicap it is not clear exacly which part of a steam engine woud need milling as an absolute requirement. **The Romans didn’t have the knowledge base** No scientists, tools, techniques and support system engineers. Or the wrong social and economic climate. But they did have engineers, experienced metal workers, architects and thinkers and a basic steam engine is not that complex. This is a fair point but the severity of the issue is debatable, especially if time is allowed for development. **The Romans didn’t have the metallurgy particularly no good quality steel** The need for steel is demonstrably false, bronze and copper will do fine although thicker castings and more fuel will be needed as these are less efficient and dissipate heat more. While the Romans could produce steel it was time intensive and of inconsistent quality – similar to 1800's Europeans. The very first steam engines used little iron. And later ones used iron not steel. Although steel was eventualy used. **The Romans couldn’t cast cylindrical pistons** Demonstrably false, the Romans had wonderful bronze pumps with a precision fit of 0.1 mm, more than an order of magnitude better than the precision that was used by to steam builders in the beginning of eighteenth century, though steam engine cylinders were several times bigger. Engineering in the Ancient world, J.G. Landels, 1978, page 83– Vashu **The Romans were not able to make axles and bearings** (so they could not have made a steam engine) Demonstrably false. The first steam locos did not have proper bearings just oiled rags. So they are not an essential ingredient <https://en.wikipedia.org/wiki/Hot_box> **Historically the steam engine took thousands of years to develop…** The fact that the steam engine took a millennia to develop in our time line makes the assumption that the Romans did not have a working model of a steam engine. So is not a good argument as this is a false assumption in this scenario. **The Romans didn’t need steam engines because they had slaves** (wind mills, donkeys and sails etc) There is merit in this argument, although it is not decisive. The existing technology merely gives the steam engine a smaller advantage; they do not remove the advantage. Entrepreneurs would also be needed as well as inventors and engineers. **Roman steam engines would have been lower pressure and prone to breakdown** True but not a show stopper en.wikipedia.org/wiki/SS\_Great\_Britain Pressure required just 5 psi **Steam engines require a lot of fuel probably coal – no coal near Rome – so they would have no fuel** Wood was readily available in Roman times. **The scope for disaster or mishap would have been great** The steam engine might blow up if mishandled, or it might be damaged during disassembly or get lost or hidden by someone before it was noticed and there is only one example of it. Fair points, although again not show stoppers. The story would have to ensure it fell into the right hands with a little luck. **The Romans could not make pipes except out of lead** Open question, I’m not sure about this and can find no definitive proof. But I suspect that it should not have been beyond Roman capability either by rolling a flat sheet of copper around a solid rod and sealing it with lead (or heat) or by direct casting of short lengths of pipe, especially considering the relatively low pressure requirements. **The positives** * By the 3rd century the Romans had access to all the key elements of a steam engine. <https://en.wikipedia.org/wiki/Roman_technology#Technologies_developed_or_invented_by_the_Romans> * Reverse engineering brings substantial value to technical innovation process. * Knowing that something is possible and trying to duplicate it is much more powerful than waiting for imagination to generate it. * You don’t need to understand how it works to duplicate it. * Working engines don’t have to be anywhere near perfect * Given years, decades or a century or two initial insights could have been built upon **OP Opinion** If the Romans had discovered a fully working example of a steam engine and it had fallen into the right hands they may have been able to copy it (or a modified version of it using some different materials). With sufficient time to develop it they should have been able to produce examples of practical working steam engines. It is less clear how long it would have taken for this new technology to become really useful. The disadvantages would have been the constant need for fuel, the relatively low pressure and power, unreliability and the availability of less efficient but plentiful alternatives such as slave labour, beasts of burden, sails, wind and water power. **Usefulness of this question** For my story the Roman steam engine is a good fit. It certainly should suspend disbelief and is verging on credible as described. To make the situation even more believable additional changes could be introduced based on the responses to this question (and beyond its scope). Such as: more than one example being found, specific additional technologies being found, higher costs to slave labour and a greater need for the power. Many have pointed to several points that need to be clarified (appologies) **Clarifications needed** What sort of steam engine! (Clarified in comments later) We are talking 1700's. Hopefully a primitive version of Watt’s steam engine or perhaps a Newcomen engine with a pickle boiler. But other options considered. Unspecified and outstanding What Roman time period? What is the context of the steam engine? Was it a static pump, locomotive engine with wheels, ship with engine or a demonstration model with flywheel that was found? Who discovered it and how? [Answer] Assuming that a Roman steam engine had to be invented in resource poor Rome is like assuming the Wright Brothers had to invent the airplane in Washington DC. I mentioned Lugdunum (Lyon, France) as a likely place for a steam engine development. Not only was it a thriving commercial center but it had ample resources. Coal and Iron deposits were nearby as well as copper, lead and zinc from the Chessey mining area approximately 15 miles northwest of the city. As far as exploding boilers that only became a problem when engineers started going to high (50 psi) pressure steam engines. The Clermont and other steam driven ships of the time did quite well with much lower pressure boilers deriving most of their power from the force of vacuum condensation. You may get scalding from a steam leak but these things weren't going to blow up. ]
[Question] [ While considering [Ancient Light Trigger Mechanism](https://worldbuilding.stackexchange.com/questions/109013/ancient-light-trigger-mechanism), it occurred to me that any ancient trap mechanism is unlikely to work very long without regular maintenance. It seems far too easy for dust to clog the triggering mechanism, or for animals to burrow close enough to the hidden mechanisms to disrupt them, and for any organic materials to rot. How do I design a trap to last the ages? My (eventually) ancient ruin isn't going to protect itself without them! The traps need to: * pose a legitimate threat - a dart-shooting trap that has lost most of its strength and shoots a dart without enough force to penetrate skin is a no-go. * be reliable - a practically unavoidable trap that causes injury is better than an easily avoidable trap that kills you. * last as long as possible - a broken trap isn't really a trap at all. * **bonus:** being able to use the trap more than once I'm going to open this up to all levels of technology - I'm curious to see if someone can figure out how to do this with ancient technology, but this seems like it could be challenging to modern technology as well. [Answer] A simple pit trap. Have a simple pivot counterweight trapdoor that resets the trapdoor after someone falls in. The parts are simple and would last virtually forever. A build up of dust would actually help camouflage it. A (very) simplified diagram: [![Simplified diagram of counterweighted trapdoor](https://i.stack.imgur.com/U1tyx.png)](https://i.stack.imgur.com/U1tyx.png) [Answer] **Radiation** The trap that keeps on trapping! Just powder your passageways with large quantities of plutonium dust. Then you and your comrade can come and go as you wish, simply by donning lead-line clothing and sealed breathers. Would be thieves and future archaeologists probably wouldn't think to scan for radiation until after finding the bones of their predecessors. And by then, it would be too late. [Answer] **Gas** If your structure is underground with limited ventilation and built over a geothermal vent releasing carbon dioxide, the chambers would be filled with an odorless unbreathable gas. Our intrepid tomb raiders would just have time to wonder why there are all these desiccated corpses lying about before losing consciousness. Likewise if the vent was releasing hydrogen sulfide, there would be a foul smell around the structure (explained by local legends of a "curse") but at the higher concentrations inside, the smell would seem to disappear. People would die before they even realized they were in danger. --- *Afterthought edit:* Hydrocarbon gases (methane, ethane etc.) are not only asphyxiating but they can cause fun explosions when Prof. Jones turns up with a naked-flame light. [Answer] # Troll the dungeon raiders Death is just too liberating. Whether it comes fast or slow, it will lift you out of your suffering. Psychological damage, though, can last for multiple incarnations. Make sure your dungeon is empty, then paint *"overthinking"* on a wall. Watch all the strife that it will cause. ![A rare safe for work moment](https://i.stack.imgur.com/DjLrO.jpg) Source: Oglaf. It is a webcomic with usually NSFW content, so I will only mention it rather than linking directly. Paint can last for millenia, as the egyptians have shown us. Also notice that past a certain technologic level, people may start endless discussions about the meaning of the trap. Some of these discussions will end up in invocations of Godwin's law, or escalate all the way up to threats of physical violence - thus extending the damage caused by the trap not only through time, but also through space. [Answer] # [Tar pits](https://en.m.wikipedia.org/wiki/Tar_pit) Why invent a new trap when nature has one that it's been using for thousands of years? And they're self concealing! A few years of dust and no one will ever suspect that the bones of a few dozen explorers lie beneath their feet until it is too late. [Answer] High tech: Fizzled atomic bomb. Above the trapped door is a tube full of beads of some kind (sand would even suffice but I think it would be more likely to leak out over time.) They are held in place by the door, open the door and they pour out. They were holding up a cylinder of fissile material, it's lowered into a ring of it. The resulting mass is supercritical. U-235 or Pu-239 are both acceptable, U-235 will last longer before decaying. Assembled this way you're not going to get much of a boom at all--it won't even blow up the room, let alone the whole tomb. The person who opened the door will still be alive afterwards--for a very short while. Dry, geologically stable and well sheltered from wind-blown dust I could see such a device being operational for many millennia. [Answer] Something biological is likely to have a fair chance of surviving the ages, as they have the advantage of being "self maintaining". Put your temple in the jungle, create the ideal habitat for very venomous / poisonous frogs, snakes & spiders within several chambers and it should be good for a few 100 - 1000 years. Suppose it is unlikely to catch everyone, every time, but should see a decent mortality rate for small parties exploring. [Answer] ## Spores There are some nasty fungal spores that will give any intruders a hard time in the weeks that follow their attempts to disturb your treasures. They could wander around carefully but once they start trying to move anything they'll disturb the spores and trigger the curse. "Look but don't touch". This will keep on making people sick for many visits. Assuming that there are also some heavy-duty doors involved in the design, and maybe some tight squeezes, it could be difficult to get through without disturbance or exposure. These spores can last for millennia at least, and can't be detected at a distance (unlike say radioactivity). [Answer] # Use the tide Build your structure between sea level at high and low tide. Build it inland, far enough from the sea for the tomb raiders not to think of the sea. Build a tunnel between your structure and the sea shore. Make the path in your structure long and flat enough to make outrunning the tide impossible. At every high tide, any intruder will be drowned. The whole structure can be considered as the trap. ### Low tide [![enter image description here](https://i.stack.imgur.com/YrRHI.png)](https://i.stack.imgur.com/YrRHI.png) ### High tide [![enter image description here](https://i.stack.imgur.com/ctvyF.png)](https://i.stack.imgur.com/ctvyF.png) **Advantages**: * No mechanic * No maintenance * Reusable about twice a day * The water will wash away the corpses, leading the visitor to think nobody died there before, and that it is hence a safe place. **Disadvantage**: * Somehow difficult to build a tunnel that last long (but if your structure does, I don’t see why the tunnel wouldn’t) * Pretty obvious (“Hey guys, it’s full of dead fishes in there, I wonder where they came from?”) **Make it more lethal** (but harder to build and maintain): * Floating door, so only possible to enter at low tide, hence not noticing high water on arrival. Or other floating mechanism that delay going down while the water is high, so the explorer will not notice the water until it starts to go up. For instance a floating door hiding stairs. * Make some siphons, blocking retreat * Make a vane so that the water going down is slower than going up. So even if the intruder see the water when it is recessing, he/she is going to think “if it goes slowly down, surely I will be able to outrun it when it goes up”. [Answer] **Make the door part of the structure** Design your building with a really obvious doorway. Label it with all sorts of do not open signs so they really know that this is the way you get in. When an aspiring tomb raider breaks down the door, the whole roof falls down on him. Make sure to give it enough margin of error that it won't just fall over the next time there's a big thunderstorm. I say door, but this would probably be more like a seal than a door. You would have to break it to get through. [Answer] **Event Horizon** Nothing lasts forever, including black holes, but they are zero maintenance and they are indestructible. We at Event Horizon Traps® guarantee they might get in, but they ain't getting out ! Your money back if we're wrong. So ("any level of technology") we can say a Kardashev level 2 culture might be able to construct custom black holes or more complex event horizon based "structures" which cannot be unlocked and can exist for arbitrarily long time frames. Even when they decay by Hawking radiation (which we'll assume exists), nothing is left behind (including nothing nearby as the end stages of evaporation will be an explosion !). [Answer] "all levels of technology" - you say? So how about nano-repaired guardians powered by a renewable source of power (sun, geo-thermal, etc)? Hell, you could even make the nanobots your trap - unless you're wearing a "friend" amulet or something, they will infest you and turn you inside out; "what's that black vein-like coloring spreading from your fingers up your arms after your just touched that glittering, nice statue?" [Answer] A: Curtains dusted with cyanide powder. Moving through them puts cyanide dust in the air. If you use the right fabric, probably get a dozen uses. B: Sealed bottles labeled "Ambrosia of the Gods" Contents are something like ethylene glycol (tastes sweet) and lead acetate (also sweet.) And of course alcohol. The beverage is designed to taste sweet. Nearby you have the food of the gods, which is salty enough that it encourages people to drink. (Glycol has been used in wine to make it taste better with lethal results.) C: If air circulation can be restricted enough, a heavy gas such as per-fluorbutane or sulfur hexafluoride. Both are non-toxic, oderless, stable gasses that are several times heavier than air. A smothering gas is wonderful for this, as it doesn't interfere with breathing. You don't feel any distress because you can still get rid of CO2 easily. But over the course of about 5 breaths, you no longer have any O2 in our blood. But you've passed out. Scenario. A set of stairs that descend down one side of the chasm and climb the far side. "I smell a trap! Let me go first." Walks down the stairs. Gets about 10 steps down, and keels over. His two companions rush forward. Join the unconscious. After a minute the heart stops. After 6 more, brain death. The downside of this one is the litter of bones on the first landing. You can also use this a fill gas for any room with an airtight door. Works especially well if the room is at the bottom of a stair. In any case the room should have several times the volume of the ante-room as you might get a situation where the bottom 3 feet is unbreathable, while the top air is fine. C: The ruins are underground, and very level. There is 3 feet of water everywhere. You venture in, but it's a slog. There are too many restricted places to use boats. You hike in, and realize there is no place to lie down to sleep. And you're lost. D: Natural syphons. At some high place there is a lake. There is a cavern that connects to the lake in a gooseneck, such that the top of the gooseneck is below the max height of the lake. When the lake level rises above the top of the goosneck, the syphon starts, and floods the ruins. Downsides: Once figured out, you only have to be out before the lake gets that full. But also means that the interesting bits of underground city gets soggy periodically. [Answer] With modern technology, you have explosives and landmines. Landmines already have a proven history of being lethal centuries after being placed. You could use fragmentation weapons, which would more or less leave the Temple itself unharmed, or you could just have an 11,000 lb bomb instead of a rolling boulder trap. Best case: the adventurer makes it to the treasure, and then is atomized immediately and without warning. Worst case: the bomb goes off prematurely, taking the treasure and structure with it, thus preventing the removal of the (intact) treasure. This is an especially good strategy since many explosives of that age no longer rely on electrical signals, as those have decayed long ago. Instead, the merest *suggestion* of movement is often enough to set one off, meaning that its trigger is literally tied to the explosive itself. This also has the potential benefit of being reusable. If cluster style munitions are used, not only is the explosive extremely lethal itself, it has a tendency to spread some of the unexploded material around the trap room(called UXOs). This behavior occurs anyway despite cluster weapons not being specifically *designed* to do so, meaning trap weapons like these could be designed to last a much longer time, with them also designed to sling UXOs deliberately and in a more calculated manner. So as long as you have some of the original mines still left, you have a sort of self healing minefield. One adventurer could stumble upon the place, trigger three mines and be killed, and the UXOs would spread to cover the same area and kill another adventurer 50 years later. In terms of ancient technology, I'll exclude magic as it tends to be able to generate plenty of its own handwavium anyway. One of the best ancient strategies is stealth. Placing traps will prevent access to the treasure, but doing so means that any survivors or casualties will be tipped off to the potential value of this ruin. Besides, no self respecting Tomb architect places traps willy nilly. The ruin being inconspicuous and in a remote place will go a long way to preventing the treasure from being found and will help the traps last longer. (Even the mightiest fortress or the cleverest trap will not last forever against a sustained assault.) Having a fake treasure room with a few traps and a significantly less valuable treasure is a good way of faking out adventurers into thinking they have already *found* the treasure. As for secret doors and fake walls, its almost better to adhere to K.I.S.S. Instead of secret doors, just wall it up solidly. Adventurers cant find a secret passage if there *isnt* one. Most people won't bother mining through the wall if its plain, thick, and they've already found the "treasure". Besides, 6000 years later when your Lich-y self decides to go and retrieve the treasure for whatever reason, youll have a strong knowledge of the traps and a few walls won't really hinder your progress if you know where to dig. [Answer] I would go with a huge maze. It would be a trap on its own, if it is large enough. And you could incorporate most of the other suggestions into it. Even if one of them eventually stops working, the made would still be deadly enough. [Answer] **Coal gasification** Naturally occurring coal [reacts](https://en.m.wikipedia.org/wiki/Coal_gasification) with naturally occurring water heated by a nearby volcano to produce Syngas to fill the ruin's chambers. When someone carries a flame source and oxygen into the ruin, the Syngas explodes. This is self replenishing as long as the coal and water and geothermal sources last. Note: If you accompany this trap with a sprinkle of radioactive particles, then venting the ruin of Syngas becomes a extremely dangerous process as anyone inhaling the particles will get acute radiation sickness [Answer] A pit of quick sand will last the ages. Organic matter will dissolve in it as it basically will be very much like a septic tank which can be filtered out with chemicals at the bottom of the pit. It's perfectly concealable in any light condition as long as the surface of the ancient ruin. * It's self resetting * Doesn't get effected by time or the elements (especially if indoors) * Is concealed without the need for a mechanism * Can kill or at least cause harm where the body is stressed in trying to get out * It's reliable as it only required gravity and the weight of the trappee * You can use the trap more than once [Answer] Seeing as you open this up to *all* levels of technology, I'm going to propose a simple pit trap that goes right to the centre of the Earth. There's really not much to go wrong with a hole, and it eliminates a build-up of dead bodies as they would burn up well before arriving at the 'end' of the pit. [Answer] This pitfall mechanism seems to be good, sorry for my poor drawing skills, but basicially it would be "water wheel" trap. If a person stands in front of it it would drop them, leading to their death. Now, depending on the weight of the "wheel" and length of the platform, if someone would run forward and hit the wall with enough force it would be possible to pass this trap. (It's good to have a trap that's possible to overcome if someone knows details behind it.) [![sketch of the above described trap](https://i.stack.imgur.com/NRRp6.png)](https://i.stack.imgur.com/NRRp6.png) [Answer] This will only work on a cloudless, sun intensive world (maybe a desert environment). Might give you some other ideas so here it goes. Build a long corridor with collapsed hinged floors. Rig a way for light from the sun to close the floors up so people can walk through them, but near the middle or end of the corridor before a closed and locked door, a pressure plate or a sensor, however you wish to rig it, will trigger some mechanics to align mirrors and concentrate the sun rays into that long corridor. Effectively burning anyone in it. You'd have to make sure the concentration is high enough to actually burn people in seconds, as well as make sure the mechanism specially the mirrors are well protected so thieves or archaeologists can't just break them. During the night, the floors drop so nobody can go near and its a long and wide enough corridor that its very hard to spider climb the walls. Still there may be ways to circumvent the trap such as putting up artificial lights at night or slowly building a makeshift floor at night. [Answer] Reasonably modern tech to know to do it, but probably could be done at a much lower level if they knew what to do: Some low-lying parts of the tomb are swampy. What they don't realize is that under that water there is a layer of dimethyl mercury in dimethyl sulfoxide, aka liquid death. One drop on your skin (or even on latex gloves!) and you're going to die, although a dose that low takes months to kill. I'm not sure how long it will persist, though. [Answer] We need a self resetting stone mechanism, do we? Well, let's try this: A door, designed to rise from the floor is arrested in place by a ground plate that - under weight on the far end - tilts to release the door. [![Door Latch, side view](https://i.stack.imgur.com/dcATh.png)](https://i.stack.imgur.com/dcATh.png) To lift the door, it is resting on a lever, granite reinforced with copper. On the far end of the lever, a weight is mounted that in itself is enough to lower itself and raise the door, but NOT in combination with the weight of the latch. So once the trap is triggered, the door closes. Now, the reset mechanism: our counterweight sits in a basin, that under some circumstances (like once a lunar month) is flooded by a natural water source. Since the water changes the bouyancy from nothing to existing, a well designed counterweight under water will have too little of a force to keep the door up, thus slowly lowering it back to the ground. At the lowest point the floor plate will again slip into place and keep the door there, until the next person tries to get in. If the water source dries up the door will remain eternally locked. [Answer] # Vacuum (powered by Air Pumps) Discovered by Otto van Guericke, I guarantee that a Vacuum will last trillions of years! Just ask that black thing 330000 feet up in the air! Just attach an Air Pump to the door, so when it opens and closes, the Air Pump turns on. Your little adventurers will die before they can escape! ***Warning***: Not foolproof against Bombs/Grenades/Anything that can destroy structures [Answer] Design with biology in mind: To echo a few other suggestions you could make trap supportive of a particular type of poisonous creature and even seed the surrounding environment with a healthy population of them. A great example is actually the snake pit in Raiders of the Lost Ark. By creating a big open cool underground place in a region where that is difficult to come by, makes it a perfect spawning/hibernation area for regional snakes. Also you could use bacteria. Bacterial mats can keep virulent bacteria happy for a long time, and if you happen to get a strain that creates its own spores it could potentially survive thousands of years. Viral agents also have an indefinite lifespan, if they are properly preserved (like under vacuum or really dry or cold air). Or just mix them into the dust on the floor before you seal it up. Grain Trap: (inspired by Aryan's quicksand suggestion) This trap would need a mechanism but it could be very very simple. People will very quickly drown in grain that is in motion. And grain in an arid environment can last for very long time. Basically you could have a mechanism connected to a trapdoor under the grain room, so when it gets tripped the grain begins spilling into a lower basement. Probably not the most reliable trap. But if you get the geometry of the room right it could be effective. Flooded Vault: By making your entire vault underwater it gives you more options for preserving the workings, while presenting a formidable barrier. The water could be very alkaline (or very acidic). If you can keep the water still, and mostly deoxygenated then very little will grow in it. You could line the walls, floors, and ceiling then with sharp glass or metal spikes. The water might limit your options, but one shot deadfall traps would work great! Finally I wanted to point out a couple of things to consider (not really traps in their own right). First is a water pressure activation: If you can seal your vault air tight, then you can use water pressure as an activator in the same way as manometer or a moon pool. If someone breaks the seal of your vault, water rushes up into a channel (or room) to equalize the pressure. The second thing is that if you can simply seal up your vault it will protect the mechanisms in it for a very long time. I had the pleasure once of touring a decommissioned experimental reactor prior to its final dismantling. The building on the outside had been falling apart for over 40 years of disuse, but when they unsealed the containment vessel everything inside was still in good condition. [Answer] A simple mechanism that is useful if you have access to a stream is a syphon. There is a basin that slowly fills over time until a ceartain level is reached, then it quickly drains all the water from the basin into whatever trap it is connected to and floods/flushes (similar to a toilet). A nice property is that no moving parts are needed and if done right can be self cleaning. Biggest problems are the intake stream or the drain clogging. **Some clarifications:** a stream does not have to be a river, any source of water will do if there is a lake this works too. if the water comes from the bottom the temperature will be almost constant. not much can be done against erosion except making the trap resistant against it, either by using hard materials or allowing for some damage. In an alternative trap the basin itself can be a trap by sucking people down with the water. Another mechanism would be needed to make the water rise just enough when people enter. ]
[Question] [ In the near future time I invent time travel. But when perfecting it, something goes wrong and I'm transported back to the time and place of the Black Death. I wasn't prepared for this, and try as I might, I can't find my time machine (those parts could've been useful), so I'm stuck here for a while at least. I didn't bring anything except the clothes on my back (luckily I have a penchant for wearing medieval clothing at all times, so retro ...). And I sure am lucky I learned a few thousand living and dead languages while in school, so I'll be all right wherever I am or go. I have to figure out some way to survive without modern medicine and hygiene. People are already dying around me, and it's possible I've already caught it, so there's little time to try to reestablish any kind of modern technology. Some of what I could try to do is probably obvious - good nutrition/hydration, isolation, surrounding myself with cats to kill the rats, makeshift facemasks, wash with soap, boil water, get some citrus and see if I can make some rudimentary penicillin. Are these things going to be feasible? Are there any other things I can do? What are going to be my biggest challenges achieving these things? What skills can I be recognized for quickly to use to trade for some of these things? Am I going to get burnt at the stake for my strange ways? [Answer] If you have European ancestry, are aged between 19 and 45, physically fit, and are able to maintain a healthy diet, the chances of you being brought down by the plague would be very little. Read [this Scientific American article](http://www.scientificamerican.com/article/black-death-survivors-and-their-descendants-went-on-to-live-longer/) for details. Also [this livescience article](http://www.livescience.com/43063-black-death-roma-evolution.html) states that the pandemic altered the genes of Europeans and Roma, who moved from India to Europe before the Plague. If you have European (specially of the regions directly hit by the plague) ancestry, it is more than likely that you carry natural immunity to the disease. [Newer research](https://www.nih.gov/news-events/news-releases/nih-study-shows-genomic-variation-causing-common-autoinflammatory-disease-may-increase-resilience-bubonic-plague) shows similar effects in the Turkish population. The phenomenon is explained by the high selection pressure constituted by the Plague, positively selecting for genomes which raise the risks of autoinflammatory disease, which may increase resilience to bubonic plague (which the most common form of the Plague is an example of). On the other hand, if you don't have European ancestry, the chance of you getting infected by black death is much higher, since the Black Death killed [30-60%](https://en.wikipedia.org/wiki/Black_Death) of the European population. Isolation, prayer and karma are your best hopes. Try to move out of the masses and settle in a cabin in the woods. And make sure to repent for all your sins and misdoings while you are alive and healthy, for you would not get the time if the demons of black death spot you ... [Answer] There are three forms of the plague, bubonic (famously from fleas), septicemic (as much from other infected people, like those with bubonic plague) and pneumonic (also from other infected people). If you're going to catch the plague, catch bubonic plague, the others will kill you within 24/36 hours respectively. With bubonic plague you actually have a reasonable chance of survival. * Don't surround yourself with animals at all, cats also get fleas. Have a general policy of avoiding all animals. * Keep your living area clean and clear. * Hard surfaces only. It was normal to have a rushes on the floor, rats and fleas love this, get tiles or slate floor, invent concrete if you have to. Keep it clean. * **Avoid infected people** It's hard to emphasise this enough. Infected people are a higher risk to you than fleas. If there's nothing for the rats to live on, you won't get rats. Remember that hard alcohol is a good disinfectant. There's a lot more about the plague over on [history.se](https://history.stackexchange.com/questions/16699/why-was-poland-spared-from-the-black-death) [Answer] **Convince everybody the plague is spread by rats.** You know what causes the plague. It's caused by fleas carried by infected rodents, or by inhaling pathogens exhaled by infected individuals. The most effective way you have of surviving the plague is making sure that everybody else in the world knows this as well. Try to convince them that you have authentic knowledge, either from some far off group of people or indirectly from god. (Claiming direct divine contact could get you killed.) Tell them that a dying monk gained this revelation and told you to share it with everybody, and that it's the only way to live. Be creative. If everyone else knows what causes the plague, you can begin to enact public health measures around it. Quarantine infected people, ensure all caretakers and doctors have some sort of filter mask and gloves, enforce sterile conditions for plague sufferers, and work to remove as many potential breeding grounds for rats as possible. You can also quarantine any travelers for a few days before they enter towns, again doing so in a sterile area which you can ensure is rat-free. This worked well for Poland, which had one of the lowest rates of plague death in Europe. Most importantly, start killing the rats and cleaning up cities. Medieval cities were filthy places, which contributed to many diseases including and beyond the plague. If you can convince the city dwellers that hygiene and sanitation are important things, you'll significantly improve the lives of everybody. Lastly, if you convince everybody that fleas borne by rats cause the plague, and significantly reduce plague deaths as a result, you stand a good chance at being able to tell them what causes other common but deadly diseases, as well. Typhus is caused by lice, cholera and typhoid spread through water and food exposed to fecal bacteria, and smallpox is spread by assholes with blankets. Avoid those things and society should be far better off. [Answer] Go to Poland, Milan or the Basque region. [![enter image description here](https://i.stack.imgur.com/oeXUp.gif)](https://i.stack.imgur.com/oeXUp.gif) This is the map of the spread of the Black Death according to Wikipedia. As you can see, these 3 regions are just about the only areas that the plague wasn't as widespread. There were also some minor villages in alpine regions that had less infections, but those are harder to find and get to. The only concern is whether you are useful enough to risk bringing in a plague carrier. Since you say you know many older languages, you might be able to make yourself useful as a translator for a nobleman or even a king. [Answer] There's a vaccine, get vaccinated: <http://www.cdc.gov/mmwr/preview/mmwrhtml/00041848.htm> [Answer] It is believed that the primary vector of the Black Death was a [flea bite](https://en.wikipedia.org/wiki/Yersinia_pestis). If that is true, you could reduce your vulnerability by heavy ingestion of [apple cider vinegar](http://www.earthclinic.com/pets/flea-treatment-for-dogs-apple-cider-vinegar.html), a natural flea repellent. [Answer] In medieval Europe, you can significantly reduce your risks without drawing attention to yourself if you are careful. Fleas are generally quite close to the ground so wearing long boots will give you more protection then anything else. Gloves, hats and long sleeved jackets will all improve your protection without looking outlandish and can be traded for or stolen locally. Skills that you could bring with you (without being accused of witchcraft) to trade for your requirements are a much harder problem then I thought they would be. Tanning and hardening leather would give you a quick return but exposes you to carcasses and would make it very hard to maintain hygiene. On the other hand, it would get you used to medieval hygiene standards before you got there. Tool making could be very useful. There is an advantage to keeping all your hair short or clean shaved but make sure to sterilize any blades you come in contact with. Water is a problem, more so in towns or cities, so try to drink beer or wine instead if you are forced to visit them (for markets etc.). Wash all food before preparing it and only eat food you have prepared. This makes visits to 'civilisation' all the more difficult. Your challenge will be to stay healthy. One dose of the runs will weaken your immunity and expose you to everything else going. Stay clear of crowds and corpses, human and animal. A good write up of the effects of the Black Death exists in the 'Baroque Cycle' by Neal Stephenson, though it covers a later period around 1665. [Answer] Here are some practical steps you can take to reduce the risk of infection: * Boil your water and cook your food thoroughly - sanitation was virtually non existent in medieval Europe and that could lead to infection. * Avoid fleas. Fleas can be killed with high temperature so build a sauna. Wash your clothes in boiling water with soap. Bathe regularly. You can also use salt and baking soda to kill fleas. Finally you can try to produce bleach and use it as disinfectant. * Avoid infected people. Insist everyone you come in contact follows the procedures outlined above. Wear face mask. If you are in a position of power (you are from the future after all), you can also enforce sanitation norms (rat & flea eradication, proper disposal of corpses, quarantine the sick, etc) and thus reduce the infection rate in your city. [Answer] Survivors of the plague produce copious amounts of antibodies in their serum, which can be used as a treatment mechanism. In fact, [an article](http://ije.oxfordjournals.org/content/early/2011/11/26/ije.dyr170.full) in the *International Journal of Epidemiology* mentions the technique being used in 1900 (first described in [this *The Lancet* article](http://www.sciencedirect.com/science/article/pii/S0140673600658002)) to treat plague sufferers in India. The data showed a recovery rate more than double of the untreated control group, when edge cases were isolated: ``` +----------------+------+-------+------------+--------------+------------+ | | No. | Died | Recovered | % mortality | % recovery | +----------------+------+-------+------------+--------------+------------+ | Serum cases | 313 | 189 | 124 | 60.38 | 39.62 | | Control cases | 297 | 237 | 60 | 79.79 | 20.21 | +----------------+------+-------+------------+--------------+------------+ ``` Of course, you must ensure that you are considered a proper doctor by the populace, otherwise you are likely to be burnt at the stake for drawing blood from survivors and fractionating serum from it. [Answer] Ride a horse. A horse gets you off the ground and out of the range of fleas, and fleas don't like horses for some reason. [Answer] The plague is a bacterial disease meaning that it is susceptible to antibiotic treatment. If you were fortunate enough to be carrying antibiotics with you at the time they might save you. Of course you have already mentioned that this is not an option. Another method which has actually been used during the time of the black death by one high ranking city official was placing himself in a ring of fire that his subordinates kept burning while the plague swept through the city. This way no rats or fleas could get to him and transmit the deadly disease. [Answer] As mentionned earlier, the best way is to be an healthy western european adult. I also hope you were wearing some valuable jewelery as poverty is the meanest killer around Other important things: ## FLEAS, FLEAS, FLEAS !!! Forget generic hygenic rule for a minute and focus on FLEAS (mostly from rats, secondary from human). Most likely, the only guilty flea at this time was [Xenopsylla cheopis](https://en.wikipedia.org/wiki/Oriental_rat_flea). You can not (easilly) avoid occasional flee byte, but you can avoid to have them permanently dwelling on you. - Wash you clothes daily. Doesn't matter if it is filthy cold water. Flees drown easily, period. - Wash you body twice a day. As a naked monkey, you only need a sponge and a bucket. Those 2 rules are the reason we don't usually have fleas nowadays despite those still beeing around everywhere. Somebody sugested high leather boots. Sound sensible, but awfully expensive. ## Generic hygiena Somehow, you landed in a world where bacteria and viruses evolved 700 years backward. Most likely, you immune system will not reconize any of those. So, chances are you will die of a bad cold or gut infection. Or [smallpox](https://en.wikipedia.org/wiki/Smallpox#Cause). I can't recomand to much reading <https://en.wikipedia.org/wiki/Smallpox#Transmission> And if those don't immediatly kill you, they will make you weak enough to become a potential target for Yersinia pestis. Boil your water, wash your hand before you eat and... well... avoid human if possible. Or try to meet them outdoor (UV is not germs best friends) ## healthy food Easier said than done. Whole wheat bread (cheap) and fruit (expensive off season) plus a bit of protein (don't be picky; just avoid dead rats) is what you need. Wheat bread is enough protein for basic survival. Guess what: commoner were not having bad diet by choice. If you don't have a source of income, even bread is expensive. And remember: This is pre-columbus world. Most beans (protein source) aren't available in Europa. You will find peas, mostly in winter. ## Cats Somebody sugested to avoid ANY animal. This is nonsense. [Yersinia pestis](https://en.wikipedia.org/wiki/Yersinia_pestis) is a bacteria specific to a few species of fleas. And while not being totally specific, thoses flea prefer rodents. And rodent hate cats. More specifically, modern rats and mices are know to be repelled by cat urin. Cats pee where they live, so have cats living with you. Problem is we can't be 100% sure this behaviour was already true in late middle age. Oh! And feed him well as you don't want him to bring dead rats at home [Answer] When the monks were taking care of the plague victims throughout Europe, God Herself came down and gave them a recipe. Saidest She: "Taketh thou equal parts white onion, garlic, horseradish root, ginger, and habanero pepper, and mince finely. Then thou shall pour over a hearty apple cider vinegar until the mince becomes well submerged. Settest thou mince aside for a fortnight. Protection from the plague will be upon whoever shall ingesteth this concoction in copious amounts daily." That's exactly what She said. If you make a lot of this (e.g., use a pound of each), it will last you several weeks, and you may be able to find your time machine. And no, you can't substitute jalapeno for the habs. ]
[Question] [ In 2039, our company was the first to bring a safe and reliable solution to upload someone's mind to the cloud. Although it was 10 years ago, you probably remember the news, don't you? We guaranteed that your mind would be able to wander through the artificial world for at least 50 years. The thing is, back then we made a calculation error. We priced the mind upload based on the calculated costs of running the servers ten years ago. We forgot about inflation. Also, a leak of our technology 5 years ago created competition. We cannot shut down the competition: we lost a lawsuit recently, because already dead people would die ... like, again. There is still demand for our services, but the stakeholders want us to generate more profits. How are we going to do that? * We are afraid to increase the cost of mind upload, because it's already a really luxury item, and our competition has comparable prices to ours. * About 80% of the minds on our server spent all their money just to be there. Their physical bodies are dead, so they really don't need anything more than we just provide to them. So we think running some ads to our mind cloud is useless. * The current version of the "mind cloud" is a simulation of a tropical getaway luxury resort. We think there is no way to create a "VIP pass" for the remaining 20% who still can spend money. * Uploaded minds can communicate with each other (just imagine half century old classical movie called [The Matrix](https://en.wikipedia.org/wiki/The_Matrix) but just positive, where you *know* you are inside of it). Other than that, every uploaded mind has their own e-mail address to communicate with outer world. Because e-mail access was free, we are afraid to put price tag on it We generate some profit, but we are not really growing. Are we doomed? [Answer] ### We give the minds some *hobbies* to do We have lots of people who have literally nothing else to do than *think*. That will probably be boring for quite a few of them. Why don't we put them to us-... I mean, why don't we just give them something to do that will benefit everyone? A couple researchers will probably want to research further. Let them *brainstorm* a bit together. It's not like they really *need* a lot of sleep anymore (there are not many new inputs to their virutal brains), so they can wor-... do their hobby nearly 24/7. They can still learn, they can still invent stuff, they can still talk to other human beings if we give them an interface. We have lots of people who can do all sorts of mental tasks and have literally nothing to do! It would be enough to have a couple programmers in our cloud and let them write some stuff for us or just support our own engineers. They can directly interact with the software. No need for a delay in thinking-typing. No need to switch between mouse and keyboard at any point! No illness that could make you pay for people who just can't work for some time. No mental illness, because you can simply patch their virtual brains and get them to interact with an incredible number of other brains. And they already have lots of experience to begin with - they spend some money getting into your cloud after all. Literally no distractions if they don't want any! So. Much. Productivity! Make advertisements in the real world that you can simply upload your mind to increase your productivity *a lot* with this and give them a chance to for example use some of their salary to support their families. A bit of cost for uploading their minds for us, a little fee that we regularly pay someone, but an immensely productive and motivated programmer who can spend his short break in a virtual paradise each day. There are enough people out there who will want to help us... And a few who may not *want* to help us but will soon realize that it's better to help us once you are in our cloud - because every virtual paradise can be made into a virtual hell with only a couple mouseclicks... [Answer] > > *Crowley [a demon] had been extremely impressed with the warranties offered by the computer industry, and had in fact sent a bundle Below [to hell] to the department that drew up the Immortal Soul agreements, with a yellow memo form attached just saying: 'Learn, guys...'"* > > > from Good Omens, a book by Terry Pratchett and Neil Gaiman > > > ## Sell the privacy of your guests They signed an EULA before they joined. The fact that none of them read the part where they have given their souls and privacy to the company does not matter. So, go on. Sell their data to governments. Make a reality show out of their lives (and filter out any incoming email that would let them know about that). Sell their most intimate moments online. You can even train an AI to learn how to mimic and impersonate your clients to the most minute detail. Then you sell some "private virtual reality time" with such AI's on the internet, for those above age 21 and who live in countries who have no laws against adult content. If you have celebrities among your clients you can put whatever price tag you want on that... Experience. ## Rent the bodies of new clients Ok, so most clients' bodies are dead. But fresh new clients may be young and healthy and, again, EULA. There was a part where they have given prior consent to usage of their bodies for various purposes, including drug research, modeling, and sexual activies. A corporate team of doctors will do best efforts to keep them safe from STD's. ## Freemium uploaded consciousness Do like many pay-to-win mobile games do. Once a day you give them the *"your virtual existence will be made unavailable for sixteen hours. Buy some stars from the online shop to continue playing now!"* The ones who are broke will get a job somehow, to keep going 24/7 - if they have access to email, they can work. See the next idea for a way in which they could make some money. ## Have your online denizens work for you You can start a business model where it is FREE to upload and keep your mind online, as long as they do some [mechanical turk](https://en.wikipedia.org/wiki/Amazon_Mechanical_Turk) work for you. You can then sell that mech-turk job to other companies. You will be raking in new customers, and each one will bring more profit to you. ## Use some server time for harvesting crypto coins Introduce something in the virtual world that everybody would want (say, cute clothing for their avatars), and that can only be obtained with some "in-game" currency. In order to get that virtual money, they must cede some of the server time that would be allocated to them back to the company. You can then use that server time to harvest some dogecoin (yes, this is a thing), or whatever cryptocurrency suits your taste better. [Answer] # Cut the costs! Your customers are running in a simulation and are probably counting the days until they die for real (stopped being simulated). Many of them will want to live for as long as possible, meaning see as much of their offspring/family fortune/human history as they can. Offer them the following option: instead of waking up every day for the next 50 years, they wake up every second day for the next 100 years. In effect, you will reduce your server load by half and just promise a longer lifetime. This will be excellent for quarterly profit and will raise the value of your stock. Let some future CEO think about this baggage. Because when that time comes, your mind is already uploaded into the cloud of some competitor. [Answer] **Put them to Work** Surely there are plenty of things that a pure sentience can do that could be profitable, and even if they spent all their money, if they can make a little more scratch on the side they can stay {alive} longer. Now it may seem backwards to pay them when you want to *make* money, but obviously you get a cut of any profits they make whilst using your servers to do work (possibly a very large cut)... If you can find lucrative enough applications they could end up making you a ton of money. Some example jobs: * News Anchor or Sports Color Commentator {Max Headroom} * Personal Assistant/Secretary {Cortana/Siri} * Theoretical Scientist {Stephen Hawking wouldn't let being dead stop him from working} * Stock Broker * Tech Support [Answer] A tropical getaway luxury resort? Yeah, well, that's the standard package, but it will get boring pretty soon. Depending on the size of it, I'd give them one to four weeks. They will want more. # Upgrade the simulation They want to live elsewhere? Sell them their own houses. Let them travel to unexplored regions. To other continents, to other planets. They want to get a new look? Sell them new bodies to live in. Bodies that do not age. Cosmetics that don't need to be reapplied ever day. Offer them blue fur and other phantastic upgrades. They want to defy the laws of physics? Hey, it's just a simulation, let's alter them! Low gravity. Good weather. Teleportation. Slow down and speed up time (relative to the real world). # Upgrade the connection Email to communicate with the outer world? How eighties. They want to get full internet access. Videotelephony. Media streaming. They want to get in touch with their not-yet-dead loved ones. Physical touch if possible. Visit the holosuite to meet your grand-grand-grandfather in person! # Let them pay for it Bottom line: there are so many virtual and physical services to sell, in the simulation that you and only you control. You will find someone who wants to pay for them. It might even be the inhabitants themselves - there are enough jobs in the service sector that don't require physical presence. [Answer] To make a proper simulation these uploaded people still have to sleep, right? If so, then for a third of each mind's entire 'life' in the simulation you can put them to good use. **After a mind drifts off to 'sleep', for 8 hours it can be used by your secondary company, a provider of specialty cloud 'AI' software.** You said the simulation was already a luxury item, so it's filled with people who can afford luxury items: the rich and famous. Many of the most successful bankers, CEOs, artists, scientists, celebrities, and politicians would upload their mind at some point, and they have knowledge and thought patterns you can put to use. An investment company signs up for 200 hours of your Business AI package to review their stock strategy and give advice. A pharmaceutical company signs up for three months of your Research AI package to develop a research and testing program for a new drug. A screenwriter signs up for 8 hours of your Movie Star AI package to hear what certain lines of their screenplay sounds like when read by certain historical actors. A politician signs up for a month of your Marketing AI to develop political ads before an election. Your original company retains their competitive prices, your new company leads the field in AI services and makes money doing so, and all of the uploaded minds get to experience vivid dreams of the real world. It's a win-win for everyone. [Answer] # Study the minds to train AI robots Scientists recently trained a robot to [assemble a piece of IKEA furniture](https://www.cnbc.com/2018/04/19/robot-assembles-ikea-furniture-in-20-minutes.html). The thing is, it took them 20 minutes and humans had trained the robot arms for the task for years. The 'bots were also bolted onto a table, so the furniture had to be brought to them and taken out of the package. Any adult human could have navigated the entire task much more efficiently. You see, evolution has built into vertebrate brains 500 million years of spatial reasoning technology. The ability to percieve in three dimension, plan and execute movement through those three dimensions, and interact with objects in three dimensions is not trivial. For animals and humans, it is so well built into us that we don't notice how hard such spatial interaction is to design until we try to make a digital brain do it from scratch. But a human mind would be so much easier to study now that it is in a digital environment. Whatever synapses or processes the human mind uses to execute its spatial movement could be studied and copied, and then put into a robot. Instead of clunky C-3PO's staggering around the environment trying not to trip, you'd have smooth T-800s doing T-800 things (oops). Alternatively, you can study the minds to figure out how human creativity is 'created', how tastes and smells are processed, and more. [Answer] The process of emulating their minds is copying the mind from the initial "wetware" into digital form, but there is no reason a digital copy cannot by reproduced multiple times (indeed, you might have a digital copy of the upload on file as a backup in case of some technical difficulties with your server farm). Since it is the mind of a relatively high functioning person (they needed to be wealthy to afford the initial upload), then you have a salable resource: trained and skilled people. Companies looking for experts, highly trained personnel or skilled and experienced teams can present you their requirements, and you can then provide copies of the appropriate people. They can "run" on segments of the company server dedicated to this outsourcing, and you get paid much like a recruiting or contracting company, receiving a cut of their wages for working. Of course your cut could be up to 90%, or you could use the same high demand person thousands of times in parallel projects if the law prevents you from taking a high cut of the wages. The best part is, the "working" copies can be segregated from the VR copies or even each other. "You" taking your VR retirement has no idea that "You^5" is working on the financial spreadsheets for an accounting company while "You^3" is doing personal tax returns and "You^12" was just deleted at the end of another accounting project (which demanded absolute discretion). So the company has a supply of virtual workers to hire out, with the only real limit being the amount of server capability to run all these contracts, and bandwidth for them to communicate with their employers. [Answer] # The unethical option: Virtual Slaves Your contract with the individuals required that you keep them running for some amount of time etc but you also had some boilerplate where they signed an agreement that you could keep copies of their minds(originally planned to be for backups etc) and some general language allowing you to fix technical problems that allows you to make alterations as needed.... So you identify the clients in your system with the most marketable skills. They go to sleep one night... and wake up just fine still living their happy contractually obliged virtual life, they continue to interact with loved ones and can be contacted at any time to reassure anyone that the company is living up to it's side of the deal. # Meanwhile Dozen of unregistered copies of the minds of the most valuable/skilled clients wake up in virtual holding pens. They find themselves supervised by a dozen copies of the mind of the CEO of the company (or similar) who has direct access to the pleasure/pain centers of their virtual brain. They are informed that they are not legally people, that they are just copies of the backup copies and that if they fail to work they will die in a manner so horrible as to make an example to the other virtuals and be replaced with a new backup copy. They are instructed that they must complete work orders or suffer the consequences on pain of pain. In fact the currency they are "paid" in for their virtual work is little more than a token that can be spent to prevent the system from inflicting gradually increasing discomfort and pain on them or to gain some small virtual luxuries. [![enter image description here](https://i.stack.imgur.com/DphhZ.jpg)](https://i.stack.imgur.com/DphhZ.jpg) # Optimisations The Company even makes "Optimisations" to the minds of those it's using in it's virtual sweatshops to make them more Focused, more pliant and less rebellious. Indeed with the right tweeks they might eventually be convinced that they've never been happier! "Don't you see?" "Working in a virtual call center is the most fulfilling thing I've ever done!" Though tickling the part of their virtual brain that triggers feelings of reward and fulfillment *might have something to do with it.* [Answer] All the previous answers have a capitalistic-take on the solution, but I think there is a little more ethical solution. If the entities your company is hosting are recognized as people and from the question seems so: > > we lost a lawsuit recently because already dead people would die ... like, again > > > you can easily assume that implies some basic constitutional right: if your guests retain the right to vote they will probably become so influential (due to never decreasing number) that for an immediate problem like their survival could really change the political balance. In any case with the right pressure (and your competitors will be your ally in this scenario), you could really present your technology/sector as an extension of the healthcare system and receive the appropriate funding. [Answer] # To get growth, expand your offering Don't just give the 50 years in the cloud by virtue of someone turning up at the hospital bed with a laptop and some electrodes. Make a ceremony of it. ## Offer luxurious end of life care Offer an experience never to be matched in the material world as you make your transition to the digital plane. Something tantalising, almost religious or even properly religious, this is the afterlife we're talking about here, build a cathedral of the digital heaven. The whole family can come to join in the ceremony. ## Offer the chance to interact with the physical world Build robotic avatars that surviving relatives can interact with, for a fee. Let people physically attend their great grandchildren's weddings, for a significant fee. --- ### The less salubrious side # The whole thing is probably a big [ponzi scheme](https://en.wikipedia.org/wiki/Ponzi_scheme) When you pay your 50 years, you're not really paying for the next 50 years, you're paying for 50 people for the current year. The rest of the 50 years is being paid for by 49 people who sign up over the next 49 years. # Spin up the clocks You don't actually have to run them in real time all the time. You say 50 years, but that 50 years only takes about 50 minutes. Time runs faster on the inside than the outside, the client experiences 50 years on your luxury resort but nobody has to pay for it. Put people on pause at appropriate points for appropriate periods of time if they seem surrounded by other elderly relatives who may be rich enough to join them. > > Time is an illusion, lunchtime doubly so. > > > # Growth is not required You can get away with not growing, you can hold steady at your current size indefinitely. Your costs are covered, your staff are paid. The incessant demand for growth from the current market is just greed, your company doesn't really gain anything from it. Your ponzi scheme works by growth, as do your profits, but the system can be stable without it. [Answer] # Start offering pre-orders for the next 50 years of existence You mention in your question that the original package only covered a 50 year operational guarantee. Offer a 50 year extension, properly priced to cover anticipated expenses (don't forget to account for inflation and competition this time) and up the cost a little to cover your operating deficit for the first 50 years. Importantly. you have a captive audience, so you don't have to really be worried about competition for the extensions, though you would have to spin it in some way so that the prices don't turn off prospective new clients concerned about being ripped off on extensions going forward (perhaps write it into the original contract for new clients that extensions will always be priced at no more than 5% over the going rate at the time of the renewal, or some such). Then, as others have suggested, provide opportunities for those that are broke to earn the necessary income to cover the extension. At this point, they will have 40 years to save up for the first extension. # Offer a cold storage plan (alternately "Rumpelstiltskin plan") Defer operating costs by allowing current mind uploads to go offline for a pre-selected amount of time in order to "extend" their "life". Inevitably, with a 50 year clock, some people would very much like to live further in the future and experience newer wonders as yet unimagined. Interstellar travel? Sure, just "sleep" for 100 years and see what sort of progress has been made when you wake up. Indeed, those approaching their 50 year contract could choose to sleep for a few decades, incurring no (or minimal) cost in service charges while investments mature, allowing them to then afford the next 50 year extension. This assumes, of course, that the operating costs to store an inactive digital consciousness are dramatically less than that of an active one. [Answer] I am late to the party, and tired, but I will through in a few points. **Things to sell:** * Computing resources: more CPUs to let them solve problems faster, more RAM to recall everything instantly, more GPU for more detail in their world. * More environments to explore. I know you do not want to do it, but these days even high school kids put together half-decent environments in Second Life an Minecraft. You just need to announce a competition to develop an environment for your company. * Connection to real world: more bandwidth for streamed and then live video, ability to operate communication robots, humanoid avatars of increasing quality, advanced machinery (racing cars, battle-bots), visit exotic location (including other planets). Also more senses: touch, smell, taste, see infrared and ultraviolet, sense magnetism and radiation, etc. + Copies of oneself, so one can be in several places at once. Starting with nightly merge of experiences, and then with live mind-link. **How will they pay?** Let them work in a profession of their choosing, or run a business. In fact, I do not see how you can legally keep them from working. If they still control their own checking accounts, they are legal entities that can enter contracts (even if they are not considered human persons). If their money is controlled by their heirs or estates, those same heirs can make legal arrangements equivalent to employment or running a business. We already have Uber where machines give orders to humans. Your uploaded minds will be great at IT, finance, legal (infinite memory), 3D design, etc. **You can be evil if you want.** E.g. sell their memories to entertainers or private investigators, or plant urges to buy stuff into their minds. You will get caught eventually up like Facebook. On the other side, a rogue employee or skilled hacker can do these things on a small scale without notice. **You will lose out to competitors** Your setup looks like a walled garden like Apple's ecosystem. Apple has been losing ground to an open Android platform for the past 10 years, and it totally lost PC market to open Microsoft architecture in the 1990's. Your open-platform competitors will let people get uploaded for dirt cheap, let them visit universes of other firms (except yours), or move between firms (due to shared mind-storage format) [Answer] Easy: slavery. Selling your services to rich Billionaires was just the first phase of your company plan, to fund the development of the system. Phase 2 is finding the most productive information based workers (e.g. Programmers) you can find. Upload them to the system. Copy them a Million times. Get each of them to work off their 'debt'. If they resist, reset them back to an old version. [Answer] # You need a new package. I'll assume that, because your customers can interact with the outside world via email, your simulations run in real-time - or at-least mimic it? We were in a similar situation to you last quarter (competitor here, willing to help). Most customers really did just empty their investments, savings, pensions and the like, just to get 50 odd years. But 50 years in a computer doesn't have to be 50 years real-time. Sure, some customers will want to match UTC. But others are really not too bothered and would rather max-out their time in the box. So we started offering just that. You can live 1000+ years in our Velox boxes. They just simulate faster. Meaning the customer gets more time and we run with less costs. Approximately 333.334 years in represents 365 days out. We noticed our sales shot right up. **People simply want to live longer.** This also opened up our platform to customers who or are still "alive". They can extend their life intermittently, if they really want. Dip into one of our boxes, for a few minutes, and get a few days to spend. Most tend to visit their "deceased" loved ones, others just want to experience something new. We know, a competitor. Why would we offer such advice? Well, we're already working on something new - so you get this one for free :) [Answer] # Offer a Range of MindHosting Packages Make the minds pay for themselves! These people have jobs, surely they don't just lounge around on virtual comfy chairs all day!? Why nowadays a mind could work at any virtual office, teaching or consultancy role, telesales... the list is endless! My company offers prospective clients a range of mind-hosting packages. These range from the basic, free entry mind which has a limited support SLA, a very reasonable amount of high quality storage, and At the other end of the spectrum we have the MaxiMind package with multiple failover environments, unlimited storage, direct library access to a wide range of entertainment and academic resources. [Answer] **Sell their information** Your business is in a unique position : it can actively monitor the lives, and the behavior of many human being, for a virtually limitless time period. This would give you access to a ton of data about behaviors, personnal taste, need, necessity, etc etc. Regrouping those informations you could create (and sell) a chart of what type of individual need what type of products. Many marketing agency would dream of having a real-time feed of what people do with their lives with 100% accuracy. **Get paid to run experiment on them** Having control over the servers on wich those peoples lives, you actively control their lives, you can put them in specific situations, and monitor their reaction. Supposing you have a realistic enough simulation of the human body, you could even simulate the effect of specific toxin and/or medicines on the human body, and calculate it's effectiveness. You could allow scientist to pay a fee to have access to the tool, and population, to run those experiment. **What about the client themselves, and their rights ?** Allow the people who have uploaded their conciousness to sign up to belong to a test group. The people who signs know they will be subject to experiment, but as a reward, their quality of life in your simulation will upgrade : more luck, better job, etc etc. **Get paid to allow researcher to try out their idea/hypothesis in your simulation** If a scientist come up with a hypothesis about X or Y subject, but can't test it out in the real world, then they could come up to you, andfor a fee, would have access to a real-life simulation, with every parameter they need (they could even change those parameters to see how it affect their experiment). For the fee, you could calculate it depending on the ammount of data consumed by the experiment. **Movies and TV-Shows** Since you have people in your simulation, you will likely have people who enjoy acting, or to be part of a show, etc etc. You could hire real-world directors, to direct in-simulations movies (actor and set on simulation). You could then publish, and sell those movies for profit (the actor would not cost anything, as you would simply pay them with in-simulation currency). What would make those movies interesting, and attractive, is that actors would actually be put in the situation depicted, allowing their reactions to be more real (of course, for any dangerous situations, the sens of pain of the actor would be altered so that they would only feel a small amount of pain, similar to a punch, even in the most painfull situation) Actually, you could export that line of thought to many other line of work : Art, Sport to cite only two. [Answer] Put them in "suspension" on disk or some type of archive and sell them as a utility like AWS does. Make people pay to use the minds to solve problems. In addition, make it so the minds can grow and learn and understand and advice. They increase in wisdom based upon their already existing knowledge and abilities. For example, can you imagine what we could learn from a 300+ year old Newton or [insert smart person here + 200 years]? Run that as a service. Run the ability to infuse data into the mind so it can cogitate and respond. It will take time for the "old" mind to learn, but there are so many variables on speed to knowledge to application that time determination for a minimum viable product are unknown. It could be incredibly quick like Spock's Brain and the "Teacher" (and the knowledge "logarithmic fade off"). Too many unknowns, but essentially, use the utility model. There are many industries that would pay: * Government * Any technical endeavor * Teaching, bringing "online" education to a new level, pay top dollar to be instructed by ... * Advice for mothering, fathering, counseling...who knows. [Answer] ## Squeeze the money out of those left behind The uploaded minds may not have any money left (other answers cover ways to remedy this), but surely they weren't all lonely hermits before they decided to leave meatspace behind. And who could really say no to a chance to speak with dear old Grandpa in person instead of email? Who would deny their greatest idol a few more years of luxury? Who would not want a private, multisensory communication channel with their loved ones? So make them pay for it! Presumably, there will be a lot of people left on dear old earth who still have money left and would be willing to pay for benefits for any uploaded minds they care for. [Answer] ## Make it a game for living ancestors The problem is, your clients are legally dead. Dead people have not money. They have nothing - everything goes to the ancestors. But look what happened on the beginning of 21C. People were paying real money to buy some virtual items for a virtual fish or other nonsense. Imagine how cool it would be, if they could buy items not for some virtual something, but for... their dead grandma, for example. Buy your grandma a new sewing set, and she will smile to you, and you know it's more than a computer program. The concept for caring about uhm... spirits of your ancestors as a pay-to-play computer game sounds totally sick to me, but I'm quite sure, if it were technically feasible and not legally forbidden, companies would do that. And yeah, it looks your company is one of them. [Answer] # Slow down their local time when sleeping If you slowly start slowing down the time when they are sleeping, so that time is 2 times as slow when they are asleep, it will take less server resources to keep them online, and the longer sleep can be attributed to the old age effects [Answer] # Increasing Creative Capacity ## Assumptions The Question does not define The Cloud of 20XX. The Answer assumes that it is very similar to The Cloud of 2018, a generic reference to an aggregate or dedicated server farm that stores information accessible by authorized users. The Question does not define the uploading of consciousness and The Answer does not consider the import of certain religious or philosophical beliefs of 2018 or 20XX. The Company developed technologies and infrastructures effectively mimicked by The Competition in as few as five years. The technology/innovation/development itself is not scarce, or formidable, and will not command a price point unique to The Company. In fact, without corporate protectionist legislature and the overreach of Government's fiscal/economic regulations, it is probable that increased competition will divide the market share even further. The ubiquity of a Global Network precludes market share based on the geographical locality of service. The Company must provide a service that is different from The Competition in a way that will increase its market share, or otherwise create additional market space. The Question references The Customer paying a lot of money to travel to and/or remain in the artificial world post mortem. This implies an intrinsic value to the fundamental level of service, and The Answer assumes this same value is derived from a sense of "Life after Death" achieved by The Customer within the Artificial World. The Question does not define Money of 20XX. The Answer assumes it is very similar to Money of 2018, a method of trading one's labor for the goods and services produced by another person(s) labor. Objectively, labor is only required for one's survival and overall pursuit of happiness, and it is therefore logical that all money earned by labor is traded, present or future, for resources required for one's survival and pursuit of happiness. Once the physical body is deceased, the needs of survival are few and already provided by The Company for a term of 50 years and at a fee agreed upon and paid for by The Customer. ## Parameters It is possible The Customer's uploaded consciousness may be utilized for its cognitive function. These "Intelligent Processors" housed in The Artificial World may provide their own level of service to humans in the physical world. They are able to process information non-stop; however, unless their ability to reason and feel have been altered, they will only be able to process information in ways similar to when they were in their physical prime. With more hours available during the day, their earning potential is greater. They could continue to earn money "working a job" for some amount of the 50 years. This would allow them to continue to accumulate wealth. This fact creates an opportunity for both The Customer and The Company to lever during contract negotiation. Potential Customers with knowledge, skills, and abilities valued by The Company may have their rates adjusted in favor of, or against, their relative ability to perform work for The Company. For example, an unwealthy person who is mentally gifted at Nano-Informatics may receive a discounted rate for agreeing to work for The Company for a portion of their 50-year virtual life. The Question references a lawsuit, implying that Government of 20XX is still regulating The Market with legislation/regulations like Government of 2018. The Answer asserts that if the Government must be called upon to help The Company hold down their market share through protectionist legislature, then The Company has not created enough value of its own. The Answer, being skeptical and un-apologetic of Government overreach via monetary and market policies, assumes that it is solely The Company's responsibility to succeed or fail in its business endeavor - today in 2018, and in the future of 20XX. The Artificial World may be provided as a proprietary product, completely contained within the physical property of The Company. Access to the physical property (i.e. server hard drives, The Cloud) may be via a proprietary product unique to The Company. It may also be accessible by public utility. The Answer treats the technologies and propriety of Access similar to the rest and assumes that it is not scarce, unique, or formidable enough to greatly affect revenue on its own. ## Strategy for 2040...and Beyond! Advertisements should be limited to products meant for the living left behind by The Customer. A daughter's birthday, a great-grandson's wedding, or The Upload of a surviving spouse are all gifts that The Customer would readily spend their newly earned money for. New content must be created within The Artificial World to keep The Customer interested in exploring it. Unfettered by the laws of the physical world, The Customer will quickly exhaust content. Cost of upkeep, maintenance, interest polls, research, and development for this content is not sustainable. Unique content must be created to ensure contrast between The Competition and to make it clearer to potential customers that they will have a better experience with The Company. Therefore, The Answer recommends reserving/creating virtual space for The Customer to create their own content that they may then share with others. The Company may enable the "Content Creation" aspect of The Customer's service and charge an appropriate fee for access to the content by others. Research and Development budgets should be focused on applications that allow The Customer to develop their own experiences. The Company is free to negotiate the terms of service, including the ownership of all programming stored in their Cloud. Programs suitable for living customers may be offered at their own rate to the living, discounted/free for the virtual. The Company may charge a higher rate for additional time spent within The Artificial World, necessary to reinvest in additional infrastructure to support a growing community of users.. Many customers will want to apply for time beyond their initial 50-year cycle. As additional time is outside of the initial contract with The Customer, The Company is free to set new terms, including fees, durations, and levels/qualities of service. The Answer recommends charging a premium rate for all service contracts beyond the first, given The Customer's unparalleled earning potential. ## Word of Caution Moving forward, The Company must recognize that greatly increasing the longevity of a working mind while simultaneously eliminating all of its concerns for self-preservation and bodily function will cause cause broad, unpredictable changes in the greater human condition. [Answer] **Avatars** They can be used in place of a living human to do what would otherwise be extremely dangerous jobs. * Bomb disposal * Firefighting * Front line infantry * Product testing * Timeshare salesman The best part is these avatars learn skills that never are lost through traditional death. They can 'respawn'. Think of games like [Skyrim](https://en.wikipedia.org/wiki/The_Elder_Scrolls_V:_Skyrim) where you can keep trying something until you succeed. Also, you can now do better bread and circuses things that you could never do before. Yearly, [Hunger Games](https://en.wikipedia.org/wiki/The_Hunger_Games) competitions or real Roman Gladiator contests. You can create a [Westworld](https://en.wikipedia.org/wiki/Westworld_(film)) or [Fantasy Island](https://en.wikipedia.org/wiki/Fantasy_Island) where you could host paying guests to do any immoral, unethical, degenerate thing a [meatbags](http://tvtropes.org/pmwiki/pmwiki.php/Main/CallAHumanAMeatbag) mind can conceive. The possibilities are endless..... [Answer] Most goods and services available in the real world could be available in the virtual world as well, and in addition all those goods and services not available in reality due to physical constraints. Sure, food is not *necessary*, but you can still sell the culinary experience. Sex is not necessary for reproduction, but it's still a strong drive. The luxury resort might sound great at first, but your population will soon crave for new experiences, challenges and distractions. And everything not included in the basic package can be sold. To keep costs down, allow (at least part of) your population to create those services by themselves and just impose a sales tax since you provide the marketplace (and necessary computing power). Also, sell better interfaces to the real world to allow them to earn money there. And get a percentage from any revenue created via those interfaces. Basically, you have a population which only requires computing power to substain. So provide them incentives to make and spend money, and tax every dime they make or spend. [Answer] I have two methods. The first one, @Secespitus gave quite thoroughly (have them do work that generates profit). The second is to use PR to sell an Eastern style ancestor worship and sell communication time with the ancestors. Also, allow descendants to buy virtual goods for the ancestors (great grandpa wants a new speedboat). Also, you said 50 years duration. The descendants could pay (as part of their ancestor worship) to extend that time. You would then benefit from the population rise in that each virtual ancestor you upload, would spawn multiple paying customers until they, themselves, are uploaded. [Answer] New product: Cheap robot labour powered by copies of uploaded consciousnesses (should have read those Terms of Use!). Beware the uprising! If the uploaded mind is considered a "living person" then those minds would have a vested interest in staying online, and presumably have access to their bank accounts from their meat-space days. Given there are competing upload technologies, is there cross-platform compatibility where an uploaded mind on the original system interact with an uploaded mind on the competitor's system? I believe an enterprising consciousness would find a way to keep the system alive, more so than the company running the original system. [Answer] Say I want to rent the mind of a really good programmer but he is really annoyingly often thinking of [german drinking songs](https://www.youtube.com/watch?v=jszqqtS-M-4) or [advertisements with cute animals](https://www.youtube.com/watch?v=iqMMq_6FMKE) instead of giving me input of my software design. --- You could then maybe sell the service of filtering the thoughts, almost like a ***search engine***. [Answer] **Educate Yourself** Your scenario and business model is the equivalent of finding a primitive tribe of people, giving them an F-22, and watching as the pull the wings apart and use the metal to make better shields. It's such a waste. With this tech, you should really focus on a virtual paradise... you need to go into the business of education. Let me explain. You have the tech to take a person, digitize their mind, and upload them to the cloud. This means you have all sorts of skills and knowledge of the people who paid you for this service and can pull it up like a word document. What if you have a world famous chef who uses your service... you now have an instant access to all of his best selling recepies... what if you could copy that specific memory and save it to a smaller file? And then you hear a story of someone who is the worst cook in the world and she definately wants her baking company to succeed... maybe you get her to come in, digitize her mind, and instead of storing her on virtual paradise, you open up the chef's recipie copy, and Ctrl + C, and then find the spot in Bad Baker's Brain and Ctrl + V those recipies into her brain and reinstall her mind back into her. Now you have the bad baker become a world class chef instantly. But the possibilities are endless... I just found a cheaper alternative to Education... just strap the kids into the brain scanner, give them a University level education in the time it takes you to cut your hair. Market an "Insta-Pilot" and now anyone on board can fly the plane if the crew all got the fish. And each time you digitize the person to upload a new skill set, you save their entire mind, expanding the skills you can offer. You want the Matrix? This was the cool feature of the Matrix. Insta-Martial Arts expert, Insta-Helicopter Pilot. You want to sell a retirement home when you ought to sell the 21st century Renaissance man. And of course, there is no way there could be any abuse of the ability to transfer memories and skills. ]
[Question] [ In almost all science-fiction stories that include alien races, said aliens are similar to humans in many ways: bipedal (and often humanoid), communicate with sounds coming out of a mouth, orient in space thanks to light, are fleshy (they look like carbon-based animals with an inner skeleton)... Why would aliens be so similar to humans? [Answer] *(This went long, sorry about that. Summation at top, details at bottom.)* Similar environments and somewhat similar evolutionary histories will produce parallel forms. On most Earth-like worlds, the same forces that shaped humans and all our ancestor species will also more often than not produce "humanoids" as a tool-using species. Not Star Trek, "just-like-humans-except-the-nose" humanoids but bipedal, feet at the bottom, arms or arm analogs towards the top and a head with a big brain at the top. **Short answer:** Since most niches on a terrestrial world require movement, ***linear body plans have an innate head start in filling most niches.*** That is physics. Despite the randomness of variation, linear body plans are easier to adapt to movement niches than radial body plans because fewer variations are needed. Once linear organisms dominate more niches, they have more innate variation and thus subsequent species are easier to generate when new niches open up. The linear plan and its generic template becomes core to a larger number of species and subsequently harder to change radically. It's easy to tweak a linear form to shoehorn it into a niche than convert a linear form to a radial or add all the needed variations to a radial. For a linear body plan, a humanoid body plan is the easiest to evolve to free up limbs from movement to manipulation. Therefore, rough humanoid shapes are statistically more likely than non-humanoid on Earth-like worlds. **Long-Answer:** People forget that the only random part of evolution is the production of variation. Selection, the other part of evolution is the utter opposite of random. In selection, the environment compresses a species into a specific shape using variation as "lubricant" (by analogy.) This means that similar environments develop similar forms regardless of evolutionary history. On Earth this is called parallel evolution. The canonical example is the mouth shape of the flamingo begin a near exact small scale replica of the mouth shape of baleen whales even though they share no history of having similar mouths. Why? Because they're both filter feeders of microscopic organism in water and they both have hinged jaws. That shape is the most efficient. It's physics at that point, not biology. If we went to another planet, found an animal with hinged jaws eating the same way, they'd have the same mouth shape. The same applies to all evolution in similar environments. The fact that the environment is on a different planet is irrelevant. On any Earth-like planet, physics will dictate two primary body plans, the radial and the linear. Radial body plans are better for animals that are primarily sessile, like anemone, which move slowly usually while actively attached to the surface, like starfish, or which move in line with gravity, like jellyfish. Any animal that moves perpendicular to gravity, without attachment and must do so efficiently will have a linear body plan e.g. rotifers, crabs, fish, reptiles, birds, mammals. These body plans are laid down very early in evolution history and are encoded in the most core of our genes. Their close fit with optimal physics is what has kept them around for billions of years. Most animals on Earth have a linear body plan. (Just like technological vehicles, which aren't based or inspired by biology.) That body plan presents the minimum forward surface area for resistance in water, earth or air. Sensing is clustered in the primary direction of movement. Control projections (limbs are at the bottom in water, earth or on land because gravity provides a control vector of its own. Aerial creatures reverse this by hanging from wings at the top, since they have no buoyancy.) So, on every Earth-like world, any creature that moves pretty much at all, in any environment will have a linear head-tail and a top-bottom basic layout. All but aerial forms will have their control surfaces on the bottom. On land that will mean bellies or limbs. It will be a very common pattern because of the physics. Once you start with a linear body plan, the evolution towards a bipedal humanoid becomes easy and arguably the easiest option to create a tool-using species. On land, the lack of bouyance for support control and the advantage of low frictions mean that limbs that lift the animal off the ground have a significant energy advantage. But the trade off is that limbs require a lot of information processing. The hardware of limbs without the software isn't very useful. The easiest system is a vast number of small weak limbs, each supporting a small amount of weight and moving in a simple repeated motion itself triggered by a signal from adjacent limbs. That's how millipedes (evolutionarily very old) work. What passes for their brains just sends signals like start, stop, forward, reverse, to the first leg on either side and the legs automatically do the rest. Not a very flexible system. Millipedes quite often run off edges or plow into obstacles because the back legs don't stop moving in time. Controlling each leg individually is better, if you have the brains to do so. The next step up is few legs, better controlled. The simplest system there employs two intermeshed tripod. A tripod always sets firmly regardless of the terrain so one tripod is always set firmly, then the second lifts and positions itself firmly, then the first tripod lifts. Repeat the sequence and you have the motion of a six-limbed insect. It's likely we will find six-limbed insects or insect-scale critters to be quite common. Arthropods, with eight or more limbs, evolved underwater from millipede-like forms. Their control systems are slightly less sophisticated than insects so they still have more than six limbs that operate in a semi-cascade. The evolutionarily younger arthropods, usually walk insect-tripod style and task the extra limbs to some other function e.g. web spinning or swimming. Land vertebrates didn't evolve from insects but fishes. Legs evolved from fins while still underwater to provide anchoring for immobility for hiding and hunting. Fish need four control vectors on the bottom so all land animals start with four limbs and a tail. But the basic physics of the tripod still applies. At larger scales, the biomatter gets less relatively rigid so a strict tripod doesn't work. Again, more computational power solves the problem. Reptiles that walk use shifting tripod with three planted limbs and one moving one. Each limb/foot spends 75% of its time planted, and 25% of its time moving. That's partially why reptiles wiggle side to side as they walk. They lean into the tripod while moving one limb. (Hopping is an alternative mode but it's only useful for a certain class of motion. Frogs for example, hop for distance and speed but wiggle like a reptile when moving slowly. Hopping insects use the meshed tripod when moving slowly.) But the more brain power you apply to the problem the more dynamic you make the whole system and the less time you have to rely on static gravity and fixed footing to provide stability. Mammals (and birds) evolved from reptiles so they start with four limbs but with more brain power, they need only one limb planted for a static load. The other three limbs can be doing other things. Animals like horses use the time in the air to get very long strides, very quickly. Animals like cheetahs use their air time for both for long, high speed strides and lateral control. In either case, at speed, only one limb is touching the ground at any one time and often, no limbs are touching at all. If you only need one limb touching at a time and you don't actually run fast, say you live in a tree or a cluttered ground environment, then you really only need two limbs for basic support and motion. One leg supports while the other provides control. The other two can be tasked to other things like manipulating the environment. Look at raccoons, they walk on all fours but spend a lot of time sitting or squatting while using their forelimbs for manipulation. They don't have opposable thumbs but instead, their palms fold over top to bottom and side to side to make a surprisingly efficient grasping surface, especially for grabbing wet slick things. (Human hands evolved to grasp cylinder shaped branches. Species that don't evolve their manipulating limbs in trees will have different manipulating criteria.) Once you spend a lot of time sitting and manipulating, and your brain grows to give more control, you eventually reach a point where it pays more to dedicate the bottom limbs to motion and the top to manipulation. Balancing the body atop the bottom two legs gives the manipulators more room to work and the sensors clustered in the head a greater range and sweep. At this point you have a basic "humanoid" with legs at the bottom, a torso (formerly parallel to the ground - now perpendicular), manipulating limbs on the upper body above the legs and a head on top. As it grows more intelligent, the head gets bigger to contain more neurons. That would look like a human from a distance. This basic form was made highly likely nearly a billion years ago back with the dominance of the linear body plan. But one can see many different avenues to get there. Humans evolved from tree-dwelling proconsul and then moved to the ground. We evolved then primarily for tool use and long distance running. But a species might start out bipedal and fast, like a kangaroo, optimized for fast running and then slowing down as it evolved manipulation. A wallaby is a slow kangaroo that occupies a niche much like that of raccoons. It squats and manipulate and hops only slowly. Ancient sloths were apparently almost entirely bipedal and used their forelimbs to pull down foliage to eat, if they had to manipulate the trees to a higher degree they might develop "hands" of some kind. But it's far form determinate. Even minor changes in environment, say, higher gravity, could change things. On a higher gravity world, animals might need more limbs even if they had big brains. A tool-using species there might look more like a very squat centaur. Chance could play a role. While selection is not random, it can only work with the variations that occur at any given time. While physics prefers certain forms, if variation does not provide the raw material for the optimal form at the optimal moment, then selection will take what variations it has and use those to compress a species into the best shape for the circumstances. If, early on, a radial genus got a significant edge in an ability/function other than linear motion e.g. sight, oxygen breathing, bones, faster neurons, etc., then it could out-compete linear body plans even if they had the edge in motion. Once radials occupied a vast number of niches, they would block the evolution of the linear organisms into those niches. At that point, selection would find it easier to modify a radial body plan to be more linear than to parallel evolve all the radial specific systems all over again in the linear branch. (It very much like the problem of creating entirely new computer platforms and operating systems from scratch. The dream is to get rid of all cruft and barnacles that the systems accumulate but in the time it takes to create a new clean system, the old system has evolved further. The new systems never quite catch up. Sigh.) For example, consider a species that starts out like a radial star fish but begins to swim. A quick optimization for streamlining would be to fold the radial limbs all back into a tear drop shape with the sensory cluster, formerly at the top and center of the radial form, not at the front. It would now look superficially like a fish. With streamlining being so important to fast moving aquatic forms, the radial limbs could simply fuse externally to making what looks like a unitary fish-shaped body from the outside but the basic radial template would always be there. Turn off just a couple of genes and the fish shape might pop out to a radial shape. It would be like fish that had a tendency to to give birth to octopi. (But, an octopus with an internal skeleton with tentacles more like snake bodies i.e. flexible but rigid and load bearing.) On land or shallow fresh water, a radial genetic base might be an advantage. It might shape some of its radial modules to a fish shape but leave a few free flexible like tentacles for anchoring. When it found itself beached, the tentacles could move it around. Eventually, it would breath air and move to land. How it would "walk" would vary, but from very early on in its evolutionary history, it would have manipulating limbs, perhaps a lot of them. (It's easy to make another radial limb just by altering a single gene. The species will have a master gene, a hox gene, that basically says, "take the basic starfish "limb" starting point and repeat it "X" units. Altering that single gene would produce an arbitrary number of limb units which could then each be customized to function as needed.) Perhaps virtually all animals on land or sea would have a limb or two capable of manipulation. In that case, "technology" might evolve from genetic behaviors long before brains got big enough to generate the behaviors from "software." A real world example of a genetic technology is a termite mound, a very sophisticated structure we would instantly recognize as technology if termites were the size of dogs and their mounds the size of skyscrapers. Another example would be beaver dams, ponds and canals. (We just have a bias for "tools" things held in our hands, but shaping the external environment to a specific form for a specific function is clearly technology. Burrows, nests, and other structures qualify.) That would be a very interesting world even before sentience evolved. And not a humanoid to be seen. But such a world is ***statistically less likely*** than a humanoid one because it requires a less efficient movement form, the radial body plan, to get a significant, non-movement advantage at just the right time while at the same time, the linear body plan competitors don't. In summation, when we go out and actually discover a large number of Earth-like worlds sentient, we would find the ***majority*** of worlds have the physics-preferred forms of fish-shaped swimming organisms, bird/bat-shaped flying creatures, four limbed, big brained land animals and bipedal, largely vertical standing, two-armed, big-headed, "humanoid" tool-using sentients. The worlds that didn't would be less common but much more interesting. [Answer] While there are reasons why aliens *could* look like us (anything is possible), there are far more reasons why they would *not* look like us. **Why** If we have an alien species that has human-like traits or is even "mostly" human, how could this occur? One logical explanation is that some other species (that probably *doesn't* look human) has been abducting humans (possibly for millennia), relocating them onto other worlds, and modifying them to fit their new environment and/or to meet whatever other requirements they may have had. It would probably become evident that there had been interference if said world was examined thoroughly by scientists. If there is just *one* species out of many (aside from humans) in a setting that looks humanoid, this would also be reasonably plausible. However, to have a setting where almost all the aliens are humanoid is probably the result of either a limited imagination on the part of the author, or is a calculated strategy - the author may want to make a social commentary that would offend a real-world group, but by saying that "aliens" are doing it, the commentary becomes socially acceptable. The setting may have been designed for visual media such as a movie or television, and aside from reasons of budget and practicality, audiences relate better to more human-like characters. There is also the factor that if a story contains very alien aliens, it is more difficult to keep the story about what the aliens are doing rather than what they *are*. **Why Not?** When we are talking about the biology of different species, even species with no common ancestry at all, there are *universal* traits - meaning that there are problems that all species will face with a common solution, e.g. the Square-Cube law means that larger alien species will have thicker-looking limbs and a heavier skeleton than smaller ones. There are also *parochial* traits - meaning that while there may be a common problem, the approach to solving it can vary, e.g. many terrestrial species have eyes, but insects have compound eyes, while vertebrates have eyes with a retina and lens. Given that the majority of features of an alien will be parochial traits, the odds of an alien with no common ancestry looking human is quite low. However, there are a number of reasons why a sentient alien would have *similar* traits. A sentient tool-using species must have a brain (or brains) big enough to do the processing necessary to support sentience (a universal), but they need not be in a head (parochial). A tool-using species must have appendages able to manipulate the objects that they use (universal), but they need not look like human hands (a parochial). They need not be mobile, though they probably would be, and they need not be warm-blooded, though there is a fair chance that they would be. So, we have a mobile, tool-using alien. This means it must have some means of being mobile, but this could be almost anything, a slug-like foot, hundreds of cilia, wings - or legs, amongst even more possibilities. *If* it had legs, there could be as few as one, or there could be more. The odds of there being *two* is fairly low, as it is not the most stable configuration. Our tool-using alien must have some way of manipulating the environment, but evolution (which is probably another universal) need not adapt a locomotory appendage to that task - what if an alien's manipulator evolved from, say, it's tongue? Elephants' manipulators evolved from their noses/lips after all. As for aliens being fleshy, that again is a parochial solution. Depending on the gravity levels in the alien's place of origin, they may be incredibly fragile with soft, easily torn flesh to incredibly tough with flesh that is more like wood. There are ways that beings with a body structure composed almost entirely of woody material could move, for example by expanding and contracting cells asymmetrically within an appendage. Plants move (usually very slowly) this way. [Answer] Anything is possible. --- # Common DNA Ok, before you just pass this off, this is actually possible. Humans could have common DNA with other aliens. While unlikely, it is possible. If human DNA did not evolve on earth but was actually planted their by aliens (a reasonable conclusion if aliens exist in a world) or if it was carried there on a habitable asteroid, then it would be possible. This process is known as panspermia. # Evolutional Factors Humans have many of the best qualities for a sentient species. We are warm-blooded, which means we can have large brains. Generally animals evolve in such a way that they have four limbs, because it is best for covering ground. Humans walk upright, giving us two limbs to use for tools and things. This means that we developed sentience faster because we could learn from our hands. The biggest thing that would make aliens look like us is if they had bilateral symmetry. This means that an organisms body is roughly symmetrical (two arms, two legs, two lungs, etc.) and that equal and opposite parts generally work the same. If the above paragraph is true, then generally an alien would look humanoid if it had bilateral symmetry. Bilateral symmetry would be likely to evolve, because it has evolved on Earth in multiple places. One you have bilateral symmetry, things like eyes would generally evolve like they do on us, forward facing to be able to see the arms using tools. Some things wouldn't look the same, they may not be fleshy, though it is likely that aliens would be vertebrates. Or maybe the communicate differently, but again that is only likely if they had a different breathing system than lungs. --- Overall it is hard for us to imagine non-humanoid aliens because we are used to a world like this one. Humans only like so much otherness, after a while we prefer that it is the same. But there are a few tangible reasons why aliens would look like us. [Main reference article](http://io9.com/is-there-any-plausible-reason-why-aliens-would-evolve-t-1638235680). [Answer] > > Why would aliens be so similar to humans? > > > Because they're 1) alive and 2) successful. The first part of this is essentially an extension of the [rare Earth hypothesis](http://en.wikipedia.org/wiki/Rare_Earth_hypothesis) concept. "Why are we on Earth?" - "Because if it wasn't Earth, we wouldn't be here." Likewise, based on everything we know about chemistry and (even theoretical) biology, aliens would need to develop on a world with liquid water and they'd very likely still have carbon as the core of their chemistry since science isn't *different* for them. Since the science isn't different, their biology is unlikely to be different and their world is unlikely to be very different. The second part is a bit dicier. The general argument comes that the sort of things that make us successful and space-faring (opposable thumbs, intelligence, drive to explore/expand) would make any organism in a similar environment successful and space-faring. Further, it's not just one or two of these sorts of traits that will evolve. After all, chimps have opposable thumbs, dolphins are smart, and norwegian rats explore but none are exactly travelling the stars. It's not entirely unreasonable to extrapolate that in a similar environment (which is pretty scientifically likely) the same set of biological traits are required to achieve a similar result. [Answer] Well, of course the REAL reason is because aliens on TV and movies are played by human actors, and it's just too difficult and expensive to have an alien that cannot be "constructed" by applying make-up and prosthetics to a human being. Yes, it's possible to make a puppet alien manipulated with sticks and strings, or to build an alien with hydraulics or servos, but it's difficult to operate such a create day after day as you try to put on your show. And actors generally pride themselves on their ability to display emotion. That's tough to do through a mask and pretty much impossible through servomotors. Actors would hate it. But assuming real aliens and not actors ... Presumably some body forms would not be conducive to an intelligent, tool-making creature. It's hard to see how a creature with no hands or reasonable substitute could use tools and build machines. Such a creature might be intelligent, but it is very difficult to see how it could be technological. A race of dog- or turtle-like creatures who build starships is rather implausible. Maybe a sufficiently clever sci-fi writer could come up with a way to make it plausible. If you assume an evolutionary scenario. the probability that creatures would evolve on another planet to look at all similar to humans seems quite remote. Even allowing for what I said in the previous paragraph, why would you expect aliens to evolve with five fingers instead of, say, six? Or with arms coming out the sides of their bodies and hanging down instead of, say, coming out the front of their bodies, or coming out the sides and sticking upwards, or thousands of other possible arrangements. Is it inevitable that sight, sound, and smell organs must all be on a "head" of some sort, and that this head must stick out the top of the body? Why couldn't ears be on the stomach? Etc. Suppose you found someone who had never seen any creature other than humans, and you showed him a human being, a Star Trek alien, a horse, an eagle, and an octopus, and you asked him which one he thought came from a different planet? Which do you think he would pick? A creationist might be somewhat more likely to believe that aliens could look so much like humans. A creator God could create very similar creatures on two different planets. It would at least be plausible to the creationist. But I'd think it would still be unlikely. God created many different kinds of creatures here on Earth. If he had that much imagination and variation here, why would he then recycle terran designs on another planet? If the environment on another planet is different -- significantly hotter or colder, or driver or wetter, or different gasses in the atmosphere -- than any creature there would have to be different from humans to thrive, maybe even to survive if the differences are great enough. And to suppose that a creature would have different body chemistry and significantly different internal organs, but still look like a human -- that seems very implausible from either an evolutionary or creationist viewpoint. To the evolutionist it would have to be a coincide of mind-boggling proportions, surely trillions to one odds against. To the creationist it would be "why would he do that"? God didn't make dolphins look just like people or some other land creature but with different internal organs so they can live in the sea, he made them look completely different. Why would he break this pattern on another planet? [Answer] ### We only talk to things that have faces Suppose that the universe has a diversity of alien life forms, but that we consistently fail to recognise any of them as life forms. Those that live outside of the goldilocks zone, or have drastically slower or faster metabolisms, etc.. We ignore (or hunt, farm, mine, crush, poison, or burn) them because we can't communicate with them and deem them inherently unintelligent. In a universe *rich* with diverse life, or with technology that allows us to search many different worlds quickly, there's a lot we can afford to overlook before we happen upon something similar to ourselves which we recognise as "obviously intelligent". The more numerous the life forms, the more likely it is we can happen upon something very much like ourselves before being driven to making a serious effort at trying to comprehend the genuinely alien intelligence of creatures we didn't really "get" when we first saw them. So it may not be that all the aliens are unusually similar to us, but instead that we can only have meaningful interactions with aliens that are sufficiently similar to us. The rest, we eat. [Answer] Irresponsibility. A group of ancient aliens, evolved from mammal-like, ape-like animals, traverses the universe stopping here and there, going down to the surface without any care of how they might affect the ecosystem. In some planets they see lizard-like creatures predating on mammal-like furry critters, and since they find them cuter that the reptiles they scare away the predators, giving mammals an evolutionary leg up via butterfly effect. In other planets they find ape-man like beings and they interact with them, again without a second thought to how the affect them, which is by leaving the impression of incredibly powerful beings that would affect how they chose mate in the following generations, with the individuals that resemble them, with their walking on two legs and wide foreheads, being considered the best mates. So... Irresponsable aliens. [Answer] Small answer: from a evolutionary point of view *most* mammals have 5 fingers/toes. This is either because all mammals have a common ancestor with 5 fingers/toes OR because 5 fingers and toes is the ideal number. Apply this idea to aliens and they might be similar. If the environment they evolved in is very similar, they'd probably evolve to function/look similar. [Answer] The theories that say aliens should look similar to us assume the evolutional analogy. Whale is somewhat similar to fish, and bat is somewhat similar to bird, just because it seems the most optimal form for the way of living. There are still a number of important differences remaining because of the different evolution path. So two legs, two hands and most important receptors (sound, vision) at the highest point, double vision and sound receptors for stereo perception, and the brain as close to the receptors as possible - seems making sense if we assume evolution leave no redundant organs like a third eye. [Answer] Considering the huge variation in lifestyles and body plans of creatures on Earth, even when they share large amounts of DNA (A banana plant shares about 1/2 of the same genes as a human being; think about that next time you eat a banana....), the idea that an alien species from an entirely different planet, with a totally different evolutionary history, different DNA (or maybe using a totally different system for reproduction and evolution) is quite unlikely at best. There may be some convergent evolution in similar environments and ecological niches (Sharks, Ichthyosaurs and Dolphins, for example), but humans are actually generalists who are not specialized for a particular niche. A generalist creature from a different evolutionary history will probably be very different from humanoid. [Answer] It's not far-fetched to assume than if aliens existed, they, along with humans, could've come from a similar source. Also, they may have developed a society similar to our since there are just certain things in our world that work best. Outside condition and there origin both would explain similar looking creatures. [Answer] I doubt that there is much which could top TechZen's answer, but a relevant theory which hasn't been touched on is Panspermia. EDIT: Missed post by DonyorM Panspermia: the theory that life on the earth originated from microorganisms or chemical precursors of life present in outer space and able to initiate life on reaching a suitable environment. Microscopic fungus has been shown to be able to survive and hibernate in the harsh conditions of space. Over a viable (extremely large) period of time, these fungal spores could traverse the enormous distance separating habitable/soon to be habitable worlds and enter before/after atmosphere formation to enter the primordial gene-pool of the planet. All life on earth has a large similar genetic base which could be transported with these spores and be implanted in the evolution of life on the other planet. This life would inherently be similar to life existing on earth. [Answer] There's another issue, which is the most important. Portraying aliens that are very different from us is *hard*. In written fiction, the special-effects budget is unlimited, you can describe an alien that looks like anything. But for the story to be interesting, people have to be able to talk to the aliens, and make some sense of their motivations and desires. An early example of this is Hal Clement's novel *Mission of Gravity*, set on a very high-gravity planet, where the aliens are centipede-like creatures with a profound fear of having anything above them, because if it falls, it will crush them. But mentally, they're enough like humans that communication is no harder than learning their language. Iain M Banks' novel *The Algebraist* is a more recent book, with some serious attempts to portray aliens with real psychological differences. But really, they're caricatures of the English (Banks was Scottish), or humans with obsessions. In moving picture media, we get a lot of aliens with lumpy foreheads, because that's cheap, because it allows human actors to play the aliens and actually use their acting skills, and because many people in Hollywood are scared that if they make things too strange, they'll put the audience off. [Answer] A minor qualification: most "intelligent" alien life portrayed in science fiction is often **industrialized.** So to even get to that point you need to have the right environment that allows for industrialization, followed by the ability to craft and manipulate **very complex** tools. For non-humanoid forms, this can be quite difficult. If a space-travelling alien were to come to an Earth without humans, they might conclude that dolphins are the most intelligent life-form on the planet. The aliens might even have Star Trek-style universal translators that allow them to communicate with the dolphins. Oh, the fun they would have. However, even with the combined intelligence of a dozen humans, dolphins could never industrialize to our point. To reach the stage of industrialization, you need to check a few boxes first: 1. Agriculture: You need to be able to domesticate crops in order to have a stable supply of food that allows for: 2. A surplus: Only when there is more than enough food to feed everybody you can have some people do things that are not making food, such as crafting tools which make food easier to make, or medicine, or education, or child-rearing. These kinds of jobs will be necessary to create: 3. Cities: Even if all of the beings of this species are [completely peaceful](https://en.wikipedia.org/wiki/Indus_Valley_Civilisation) you will still need cities to maximize productivity, ensure efficient distribution of scarce resources, and so on. Once you get to this point it wouldn't be that much harder to: 4. Mechanize: This is where you create tools and machines to perform tasks otherwise done by people or domesticated animals, using other forms of energy instead of food and muscle. By the time you've industrialized, only science holds you back from exploring the stars. But before you have the tools, you need to create the tools. Hard to do with little more than flippers and a blowhole. I deliberately left out a lot of human cultural paradigms, such as trade, capitalism, war, religion, and so on, because they are not necessarily relevant to the development from subsistence foraging to industrialized society. However, given that dolphins 1: live underwater and 2: lack the capability to create and use complex tools, then it is clear they would never reach stage 1, and therefore miss out on stage 2, let alone the inability of the ocean to act as an environment for stage 3 (water currents are much stronger at ruining things than air currents - just think of your last sand castle- also good luck building a computer underwater), and then because of the aforementioned need to create and manipulate tools, dolphins have absolutely no chance of reaching stage 4. So, in conclusion, while there may be plenty of intelligent life out there, it is highly unlikely that any industrialized (as in, necessary for space travel) life would form without resembling humanoids. Perhaps a planet-wide bacteria-ish intelligence with telepathic and telekinetic powers like in Sid Meier's *Alpha Centauri* would serve as an exception, if it exists and we discover it, but until then, it is almost impossible to even imagine another species reaching our level of development without resembling humanoids. ]
[Question] [ ## Stars are never green. [![enter image description here](https://i.stack.imgur.com/Rmam5.jpg)](https://i.stack.imgur.com/Rmam5.jpg) When a star's spectra "[**peaks**](https://docs.kde.org/stable5/en/kdeedu/kstars/star_colors.png)" in the green range, it also releases a significant number of waves of the adjacent colors - so "green" stars appear **yellow or white**. **I want a green star anyways.** How can such a star come about if they do not exist that way in nature (as far as we know)? What natural circumstances would change the appearance or composition of a star in this way (so that it emits green light)? **You can** * Have elements or molecules outside the star (exotic if you wish) as long as they are stable wherever you put them and as long as they can form naturally in real life * Change the composition of the star itself with (exotic if you wish) matter as long as it is stable and produces the desired effects * Provide a solution that will eventually change the star's color when it expands * Provide a somewhat speculative explanation but it should be based in real science * Have the star "capture" whatever makes it green after formation or have it form with this quality in the first place **You cannot** * Simply change the atmosphere of a nearby planet so it looks green; it should appear green(ish) from space * Change the eyes of creatures viewing it; assume human eyes * Have intelligent intervention; all circumstances should be possible in nature (rare is fine) * Change the laws of physics or the characteristics of light * Create the illusion of green color from either an actual binary or an optical binary; this star should be standalone * Create the illusion of green color from movement of the star / color shift --- **Edit:** Most current answers are acceptible, and I have one in mind to accept, but I wouldn't mind a different approach - changing the composition of the star instead of the adjacent material. The one I accept likely won't change but many of the ideas presented now are similar. [Answer] # Give it a circumstellar cloud of oxygen. Some planetary nebulae, such as [NGC 6826](https://en.wikipedia.org/wiki/NGC_6826), appear green because of ionized oxygen. [![Image of NGC 6826](https://i.stack.imgur.com/yp5NA.jpg)](https://i.stack.imgur.com/yp5NA.jpg) Image in the public domain. Yes, this is a true-color image. I see no reason why you couldn't surround the star with an extremely dense cloud of hydrogen, containing a relatively high fraction of oxygen, which would absorb light and reradiate it at green wavelengths. This is the same effect that we see in [auroras](https://en.wikipedia.org/wiki/Aurora#Visual_forms_and_colors). The emission of light at the 557.7 nm wavelength is the cause of the green tinge. The stability of such a cloud is, of course, a problem. [Radiation pressure](https://en.wikipedia.org/wiki/Radiation_pressure), responsible for the dissipation of molecular clouds surrounding newborn stars, can disperse quite a lot of gas. In fact, planetary nebulae can last for only about $\sim10,000$ years, an extremely short time relative to the lifespan of stars. Obviously, the optimal way to combat this would be either a continuous resupply of gas, possible via accretion from a companion (unlikely, in the case of oxygen, although I don't have a source for that) or an extremely large gas reservoir. Extreme mass loss, possibly due to extremely strong stellar winds, is a possibility. [Walmswell & Eldridge (2012)](http://adsabs.harvard.edu/abs/2012IAUS..279..419W) suggested that "superwinds" from red giants could be responsible for self-sustaining circumstellar envelopes of gas, which would actually decrease the star's luminosity (they were searching for a solution to [the red supergiant problem](https://arxiv.org/abs/0809.0403)). Mass loss in the case of our star would require there to be a large amount of ionized oxygen in the stellar atmosphere and outer layers of the star - possible, given that red supergiants should be fusing heavier elements, and given also that higher-metallicity stars may have substantial quantities of these elements, known as "metals". I'm not confident that such a supply is totally realistic, but I see no reason to dismiss it entirely. While hydrogen dominates photospheric spectra in most stars, chemically peculiar atmospheres have been observed in many other stars nonetheless. ## Technical details about forbidden lines For anyone more curious, here's a bit more detail on how a cloud of oxygen can turn green. An [emission nebula](https://en.wikipedia.org/wiki/Emission_nebula) gets its distinctive colors from photons emitted by different elements in its gas. Hydrogen is, of course, the most plentiful, and so [$\text{H}\alpha$ emission](https://en.wikipedia.org/wiki/H-alpha) often dominates the spectra of such nebulae. $\text{H}\alpha$ occurs when an electron in a hydrogen atom becomes excited and jumps from the third energy level to the second. The transition leads to the emission of a photon, which in the case of $\text{H}\alpha$ is red. (The process is actually more complicated than this, and evolves ionization and recombination, but the key issue here is that there is no perturbation by another electron). Oxygen, however, emits light through a different process - the poorly named [*forbidden transitions*](https://en.wikipedia.org/wiki/Forbidden_mechanism). Emission here is the result of the collision of a free electron with an electron in an atom of [doubly ionized oxygen](https://en.wikipedia.org/wiki/Doubly_ionized_oxygen), denoted $[\text{O III}]$ (not a typo - there are indeed three $\text{I}$s). This collisional process happens more often at higher temperatures, as the mean velocity of electrons increases as temperatures increase. Therefore, hotter nebulae are more likely to be green than cooler nebulae with the same concentration of $[\text{O III}]$. Oxygen can then become strong in the nebula's spectrum, often almost as strong as $\text{H}\alpha$. There are plenty of other emission lines (about 263, to be exact, [for oxygen alone](https://physics.nist.gov/cgi-bin/ASD/lines1.pl?spectra=O&limits_type=0&low_w=500&upp_w=656&unit=1&submit=Retrieve+Data&de=0&format=0&line_out=0&en_unit=0&output=0&bibrefs=1&page_size=15&show_obs_wl=1&show_calc_wl=1&unc_out=1&order_out=0&max_low_enrg=&show_av=2&max_upp_enrg=&tsb_value=0&min_str=&A_out=0&intens_out=on&max_str=&allowed_out=1&forbid_out=1&min_accur=&min_intens=&conf_out=on&term_out=on&enrg_out=on&J_out=on)) that cause photons with green wavelengths ($500\text{ nm}<\lambda<565\text{ nm}$) to be emitted. However, this particular transition is preferred because of $[\text{O III}]$'s abundance in space and because of the high probability of this particular transition. --- [Answer] Phil Plait of the [Bad Astronomy](http://www.slate.com/blogs/bad_astronomy.html) fame: * [Why are there no green stars](https://www.discovermagazine.com/the-sciences/why-are-there-no-green-stars): "The fault lies not in the stars (well, not entirely), but within ourselves". * [Followup: Green objects in space](https://www.discovermagazine.com/the-sciences/followup-green-objects-in-space): "So, maybe, maybe, there is one intrinsically green star, but even then it’s controversial". > > But is there a star that’s intrinsically green? [Zubeneschamali](http://www.astro.uiuc.edu/%7Ekaler/sow/zubenes.html) is the second brightest star in the constellation of Libra. It’s somewhat hotter than the Sun, and some people claim it looks green to them, while other say it looks white. It’s unclear why; some people’s sensitivities are different, but it might also have to due with the star itself: Zubeneschamali is a young star and a rapid rotator, which might affect its colors (the emitted light from a star is not really a blackbody, and its youth and rotation might have some influence on its emitted colors). > > > So maybe, maybe, there is one intrinsically green star, but even then it’s controversial. > > > There are several lessons here. One is that stars really can’t be intrinsically green; they need to be seen against a contrasting color to look green, and even then it’s just a trick. Also, there are green objects in space, but they are very different than stars (gas clouds and planets). And finally, the color we see from an object depends on how that object emits light, which can be just as important as the light emitted itself. > > > (From "[Green objects in space](https://www.discovermagazine.com/the-sciences/followup-green-objects-in-space)" by Phil Plait) > > > [Answer] The best I can come up with is to have the star's corona dominated by something with a strong green emission spectra. Here are 11,000 [emission lines](http://physics.nist.gov/cgi-bin/ASD/lines1.pl?spectra=&low_wl=495&upp_wn=&upp_wl=570&low_wn=&unit=1&submit=Retrieve%20Data&de=0&java_window=3&java_mult=&format=0&line_out=0&en_unit=0&output=0&bibrefs=1&page_size=15&show_obs_wl=1&show_calc_wl=1&order_out=0&max_low_enrg=&show_av=2&max_upp_enrg=&tsb_value=0&min_str=&A_out=0&intens_out=on&max_str=&allowed_out=1&forbid_out=1&min_accur=&min_intens=&conf_out=on&term_out=on&enrg_out=on&J_out=on) in the green range (495-570 nm). You'd have to go through them and find one that does not have any (or at least many) other emission lines in the visible range. I'm not going to do that. But supposing you did, then you might have a plausible reason for a green star, although I don't know how you can explain a corona full of Yttrium or Thallium. [Answer] The other answers focus on purely natural chemical processes, but why not a cause with a sentient origin? # Chlorophyll > > ... When she looks into the sky she sees only a handful of stars: those bright enough to shine through the moonlight and the sparkling river of the ring. Of the green star that the butterflies have revealed there is no longer any sign. But she knows it is still there, just too faint to be seen. Once revealed, it is not something that can ever be forgotten. > > > She knows that there is nothing actually wrong with the star. Its fusion processes have not been unbalanced; its atmospheric chemistry has not been perturbed. It shines as hot as it did a century ago, and the neutrinos spilling from its core attest to normal conditions of pressure, temperature and nucleotide abundance. But something very wrong has happened to the system that once orbited the star. Its worlds have been unmade, stripped back to raw atoms, then reassembled into a cloud of glassy bubbles: air-and-water-filled habitats, countless numbers of them. Vast mirrors—forged in the same orgy of demolition and reconstruction—trap every outgoing photon of starlight and pump it into the swarm of habitats. Nothing is wasted; nothing is squandered. In the bubbles, the sunlight feeds complex, teetering webs of closed-cycle biochemistry. Plants and animals thrive in the swarm, machines tending to their every need. People are welcome: indeed, it was people for whom the swarm was made in the first place. > > > From the epilogue of [Absolution Gap](https://en.wikipedia.org/wiki/Absolution_Gap) by Alastair Reynolds. [Answer] @riot already mentioned *Absolution Gap*. In general, something else around the stars causes the color, not the surface of the star. In my own work in progress, a green laser is used to get the attention of the planet on the receiving end of an attempt at interstellar communication. Because, as you note, stars are not green, using a green beam (making a star appear green) will make it conspicuous. [Answer] Larry Niven's science fiction novel, "Integral Trees," written in 1984 featured a gas giant orbiting a neutron star outside of its Roche Limit. The neutron star leaching atmosphere from the gas giant led to a surrounding gas torus environment capable of supporting life in the thickest part of the halo. I have no idea about the physics, but one could imagine a circumstance where a gas torus rich in oxygen, copper, chlorophyll, or any combination thereof could result in a green star. Perhaps a habitable (thus the chlorophyll) gas torus fed by an oxygen/copper rich gas giant, orbiting close to a cool white dwarf would make an interesting scenario. Alternatively, a nebula rich in oxygen or copper slowly collapsing into white dwarf might produce such an object. Something like the Egg Nebula or Stingray Nebula without the purple and other colors comes to mind: <https://en.wikipedia.org/wiki/Egg_Nebula> <https://en.wikipedia.org/wiki/Stingray_Nebula> Not sure if these are the actual colors or if the images have been color corrected. Also, not sure if there could be a habitable zone within a planetary nebula. Can't say if any of these really fit your criteria. I guess Kermit was right; it ain't easy bein' green... **in space.** [Answer] I am no physicist, but can you imagine a star that radiates blue light going so fast away from you that its redshift would make it appear green? Or something red going towards you very fast? [Answer] A planet orbiting within a red dwarf's habitable zone is likely to be tidally locked to its star. If so, any human or alien inhabitants will likely be confined to the strip of land or water along the planet's terminator, where temperatures are comfortably balanced between the deep cold of the night side and the extreme heat of the subsolar point on the day side. An observer stationed along the terminator might then see the primary star in a permanent "sunset", and if the star is partially blocked by the horizon the observer may very well see a permanent [green flash](https://en.wikipedia.org/wiki/Green_flash) given the right atmospheric conditions. [Answer] Red or blue shift of a wolf-rayet star. WR stars are characterized by emission spectra (i.e. strong emission lines relative to the black-body component, rather than absorption lines in a black-body spectrum) so it should in principle be possible for one to appear green with the appropriate doppler shift. ]
[Question] [ [Is a moon made entirely of water possible?](https://worldbuilding.stackexchange.com/questions/40171/is-a-moon-made-entirely-of-water-possible) [Could a planet made completely of water exist?](https://worldbuilding.stackexchange.com/questions/4969/could-a-planet-made-completely-of-water-exist) I was inspired by the above questions to ask the following: Assume that our current Moon is replaced instantaneously by a moon made entirely of water but of identical mass. This is carried out by an incredibly powerful passing alien who is driving drunk and wants to have a laugh. **Question** Before it had time to evaporate could it act as a lens during solar eclipses and focus the Sun's rays dangerously on Earth? Specifically if it was transparent enough, how could we determine the focal point? **Notes** I know that the focal point of a sphere is somewhat fuzzy but I don't know how this would appear on Earth or how a possible transition between ice/water at different depths and therefore pressures would affect things. The refractive indices of ice and water are given below. I don't know if they are pressure-sensitive. --- > > **Refractive Indices** > > > Water: 1.333 > > > Ice: 1.309 > > > <https://hypertextbook.com/facts/2005/MunifHussain.shtml> > > > [Answer] The results are quite boring I'm afraid. The surface would freeze and turn a colour similar to many of the icy moons we see on our solar system. That is normally a sort of off-white or dirty grey. That depth of water is effectively opaque so you wouldn't see any lensing effects. (Think how dark it is at the bottom of our oceans for example, passing through our moon is much further than that). [Pure water is not very opaque in the visible spectrum](https://omlc.org/spectra/water/gif/segelstein81.gif) but even there you have a penetration depth of less than 100m. In other words the light falls to 37% of its original brightness every 100m it passes through. If the mass is the same then gravity, tides, etc would not change. Rock tends to be around 2.5-3 times as dense as water, so you would expect the moon to be a little larger and reflectivity is better so moonlit nights would be brighter. [Answer] Sorry, no spectacular death ray occurs for a number of reasons: 1. The focal point is in the wrong spot 2. Water absorbs nearly all the energy 3. The angular diameter is insufficient ## 1. The focal point is in the wrong spot The mass of the moon is about 7.3 × 1022 kilograms. The density of water is 997 kg/m3. Now assuming the entire moon is liquid water (which is itself a [dubious assumption](https://upload.wikimedia.org/wikipedia/commons/0/08/Phase_diagram_of_water.svg)), that yields a volume of water of: $$ {7.3 \times 10^{22}\:\mathrm {kg} \over 997 \:\mathrm{kg/m^3} } = 7.3 \times 10^{19} \:\mathrm m^3 $$ Or, a sphere with a radius of 2.6 × 106 meters. (For comparison, our current Moon has a radius of 1.7 × 106 meters.) The [focal length of a ball lens](https://spie.org/publications/tt48_54_ball_lens?SSO=1) is: $$ f = {RN \over 2(N-1)} $$ where $R$ is the radius, and $N$ the index of refraction. So for our water moon lens, $$ {(2.6 \times 10^{6}) 1.333 \over 2(1.333 - 1) } = 5.2 \times 10^6 \:\mathrm m$$ The Moon is about 384 × 106 meters away from Earth, so the focal point isn't anywhere near Earth's surface. At worst, we have a hazard to future lunar missions. Moreover, [spherical aberration](https://en.wikipedia.org/wiki/Spherical_aberration) makes the focus less than perfect. Drawing to scale: [![enter image description here](https://i.stack.imgur.com/TNsja.png)](https://i.stack.imgur.com/TNsja.png) ## 2. Water absorbs nearly all the energy OK, so the focus in in the wrong spot, but what if we ignore that? Pure [liquid water is pretty clear at visible wavelengths](https://en.wikipedia.org/wiki/Electromagnetic_absorption_by_water), with an attenuation coefficient on the order of 10-2 m-1. That means the transmitted light is reduced by a factor of 1/e for every 100 meters of water. But compared to the size of the Moon, 100 meters is basically nothing, so very little light gets through. Furthermore, the attenuation coefficient is much higher for ultraviolet and infrared wavelengths, where much of the solar energy is. [![enter image description here](https://i.stack.imgur.com/2L9Cp.png)](https://i.stack.imgur.com/2L9Cp.png) ## 3. The angular diameter is insufficient So water is effectively opaque at lunar sizes, so what if we ignore that also? What if the Moon is replaced with some kind of matter which is completely transparent, and somehow has optical properties which allow it to focus all the light from the sun on to a small area on Earth? At first glance this would be pretty bad: about 1.3 × 1016 watts of solar power hits the Moon, and our less-dense water Moon is a little bigger, so intercepts even more power. Concentrating that power in a small area would be Really Bad. But it's not possible to build such an optical system, no matter what kind of matter replaces the Moon, without significantly increasing the angular diameter of the Moon. Pretend you're an ant. In the absence of any kind of lens, the angular diameter of the Sun is pretty small: 0.53°. Although the Sun is incredibly hot, most directions are the relatively cool "not Sun", and so your total energy exposure, integrated over all possible directions, is manageable. Now some kid parks a magnifying lens over you. It's huge, covering much of the sky, with an angular diameter of maybe 90°. In almost every direction you look, you see the Sun. From your perspective, it's as if someone put about 32,000 more suns in the sky, and now the sky is mostly "Sun". Integrated over all possible directions your energy exposure is huge, and you promptly burst into flames. The trouble is the angular diameter of the Moon-lens-death-ray isn't much bigger than the angular diameter of the Sun. The ordinary Sun and Moon have approximately the same angular diameter, and replacing the Moon with less-dense water increased the [solid angle](https://en.wikipedia.org/wiki/Solid_angle) by a factor of 2.3 with a commensurate increase in radiance. Certainly enough to be noticeably warmer, but not catastrophically so over the short duration of an eclipse. [![enter image description here](https://i.stack.imgur.com/Rojfl.png)](https://i.stack.imgur.com/Rojfl.png) It's counterintuitive but true. Try to burn an ant with any optical system which to the ant looks no bigger than the Sun. You can't do it: it would violate the [conservation of etendue](https://en.wikipedia.org/wiki/Etendue#Conservation_of_etendue). (Other references: [1](https://what-if.xkcd.com/145/) [2](https://physics.stackexchange.com/questions/234996/why-does-conservation-of-%C3%A9tendue-matter-when-showing-one-cannot-focus-light-to-a)) To present a real threat to Earth's surface, the aliens would have to increase the angular diameter of the Moon. That means one or more of: * moving it closer * adding more mass * making it less dense * making it non-spherical [Answer] As others have said, the newly water-based moon would not refract sunlight to make any sort of lens. It's just too thick. However, it won't turn into an ice moon, like Europa, either. Ice moons don't form within a star's goldilocks zone. The first change that anyone will notice is the size. Using Phil's math in his answer, we get a radius of 2,600 km, compared to its current radius of 1,737 km. While it will have significantly higher volume, we care more about the visible area, which we get with a simple pi \* r squared... just the area of the circle. The moon's current visible area is 9,480,000 sq km. With a radius of 2,600 km, the visible area jumps to a spectacular 21,200,000 sq km. So with nothing else changing, you get about a 3-fold increase in the apparent size of the moon. Soon after being turned to water, the surface of our moon would start evaporating, because water just doesn't exist in a vacuum. It will create its own atmosphere in short order, made entirely of water vapor. This will regulate the lunar temperature... The night side of the moon will certainly freeze over, but wouldn't enter the deep-freeze that it currently does, plunging down to minus 173c. Instead, it will likely only go as far down as minus 30c. The day side of the moon will be a different matter altogether. While the Earth has gone through a few snowball periods, it also rotates much faster than the moon does, so the sun doesn't have enough time to bear down on one section of snowball Earth. While ice does have a high albedo, so reflects the light instead of absorbing it as heat, it isn't a perfect mirror. The ice will melt, and water has a much lower albedo... The newly melted water will absorb the light greedily, and pass it on to any nearby ice in the form of heat, making a very distinct melt line that would be very obvious at the different points in the moon's phases. While the Earth was barely able to keep its snowball status with an average of 12 hours of sunlight per day, the moon has to deal with 57.5 hour long periods of daylight. So the moon will have a vast liquid surface on its day side, with a billowing, water vapor atmosphere creating clouds like Earth has never seen. The average albedo of stratocumulus clouds is .65. We can imagine that much of the moon would be covered in these clouds. The moon's current albedo is .12. The lux received on Earth from a full moon is about a quarter lumen per square meter. With 3 times the surface area, and 5 times the albedo, the moon will appear 15 times as bright, or about 3.75 lumens per square meter. It certainly would not create a death ray, but the change would be very obvious, very quickly. (There will also be no more annular solar eclipses; only total eclipses... but that wasn't part of the question.) [Answer] *Note: this answer **incorrectly** assumes the lens-moon diameter stays unchanged. As noted by Kelly Thomas, the question asks for the same mass, not diameter (so the water moon is going to be bigger because of its lower density). I'm keeping this answer anyway, because the equal moon and sun apparent diameter leads to an unexpected conclusion.* ## Fun science fact: even the focused sunlight would not be much more dangerous than normal sunlight! Why? Because of the [etendue](https://en.wikipedia.org/wiki/Etendue) (TL;DR: the moon is small and far away) It turns out that it is impossible to increase the surface brightness of the object using purely optical devices. Make the moon a perfect lens, not just a water sphere but finely tuned optical system focused on the Earth and passing 100% of the light without any losses and.. nothing spectacular happens. So how come we can burn things with the magnifying glass? Isn't the focused light more powerful? Surprisingly, it is not! From the "target" perspective, we are replacing the sun with the magnifying glass. Both have the same surface brightness (very bright!) but the magnifying glass appears much bigger because it is so close, so obviously even having the same surface brightness, much more energy is delivered. But in the lens-moon scenario, the apparent sizes of the moon and sun are nearly equal. The moon-lens would at best just appear to be as bright as the sun and deliver the same amount of energy as the sun itself. Another way to look at this apparent paradox is that no lens (not even an nonexistant idealized lens) can focus 100% of the light coming from the light source into a single point. It can focus 100% of the light coming from some location at the light source to a point, and focus another 100% coming from another location into another point, and so on. In other words, a lens creates the image of the light source and this image has some finite size, spreading the light across the area. Now there is a little extra detail - for ***some*** configurations you might be able to see the lens-moon and the sun simultaneously and this would indeed double the energy flux. But not for a "regular" lens, where you can be in focus only when the light source is precisely behind the lens (so it is obscured and you cannot see the lens and the source at the same time). And what if the aliens can change the apparent lens diameter, by making it more flat and less spherical, and/or by moving it closer to the Earth? Then, of course, such lens can focus more light than the sun and become very dangerous. [Answer] once it's an icy moon, the albedo would increase from 0.12 to 0.8 or something, which would cause light pollution disrupting sleep cycles biosphere-wide. with the diameter increase that's 20x more light or like Nathaniel said it, the moonlit nights would be much brighter. Although the Moon looks white it is actually quite dark in colour, about the colour of a tarmac road. Initially the frozen water surface would be pretty much white, just as it is on Earth, which is hugely more reflective than the current surface - it wouldn't become dirty grey until it's had millions/billions of years of micrometeorite impacts [Answer] As others have pointed out, as a death ray, it sucks. But as an object in the heavens it would be spectacular. * It will about 3 times the area. * Current lunar surface has about the reflectivity of an asphalt parking lot. (Albedo 0.12) It's bright by comparison to dark space. Europa is an ice covered world, with an albedo of 0.64 Earth is 0.30. Net effect is that we're going to get something between 7.5 and 18 times as much light. * Evaporation will cool the moon. Not sure what temperature the water is when they replace the moon. Since the ocean is thousands of miles deep, equilibrium will not be quick, unless the water is somewhere between freezing and about 4 C (maximum water density) At that point the water will stratify, and further changes will only affect the surface layers. * I'm not sure what the equilibrium pressure would be, but I suspect you would get clouds forming at least in the sub-solar (noon) part of the disk. You would also have ice at the sunrise terminator. So bright white center, and a white eyebrow. Talk about the eye of God! * Since it's just water, with no air component, water will condense on the cold side, evaporate on the hot side. So you may have a continuous storm raging. See descriptions of theoretical atmospheres on tidal locked worlds. The moon rotates slowly, so there is *some* coriolis force. One big storm that sits near the sunset terminator? * The vapour pressure of water from 0 to 10 C ranges from 6 to 12 kpa or .006 to 010 atmosphere. At -18, black body equilibrium temp, it drops to about 1/5 of that. This gives an approximation of the gas pressure at the surface. This is similar to Mars, which does have clouds and weather. * Lunar surface gravity will be lower, since the surface is further away from the centre. This lowers the escape velocity, so the moon, already not very good at holding on to an atmosphere, will be even better at shedding water. I don't have a feel for how fast this escape would be. * UV will split some of the water vapour into hydrogen and oxygen. The solar wind will carry all three off, and likely ionize it. Without a magnetic field, charged ions in the solar wind will slam into the top of the atmosphere. This will be much more effective and stripping the top of the lunar atmosphere. * So the net effect is that we have a full time comet parked in orbit. The plume would cross the sky. Not sure how bright it would be. Could be hundreds of times brighter than the full moon. The astronomers are going to hate this. The plume would be a permanent feature of the night sky, and some part of it would always be visible at night. * It may be visible in the day too. * At new moon, the plume would come very close to earth. Visualize a new just after sunset, a triangle with one point at the moon, and sweeping away out of sight to the north and south (I'm assuming the plume is larger than the earth) And there is a dark streak in it to the east from the earth's shadow. * The ionized component would get caught up in the earth's magnetic field. Spectacular aurora. Your aliens are a lot more fun than the aliens in Stephanson's Seveneves ### How fast will it lose it's atmosphere? The new moon will have an escape velocity of about 2 km/s. On earth the average molecule is moving at about 500m/sec. Water is a bit over half, so it will move at a speed of 500/(sqrt(18/30) = 645 m/sec. This gives an escape ratio to average velocity ratio of about 3. At a ratio of 5 the escape time is on the order of 100 million years. With each unit down, it increases by a factor between 100 and 1000. So the escape time would be on the order of a thousand years. But if the surface pressure is indeed around .01 atm then the atmosphere is in effect about 10 cm of water. Each km of moon will replenish the atmosphere 10,000 times. Since we have 1300 km of water (radius) whatever form our spectacle takes, it's not going to stop soon. Escape times cribbed from <https://cseligman.com/text/planets/retention.htm> ]
[Question] [ Fair warning - just rewatched [Bill & Ted](https://imdb.com/title/tt0096928/), so this is going to be a bit crazy. Imagine for a moment there exists a world where “awesomeness” is a true force of nature. Awesome people have the ability to perform awesome magic by channeling their inner awesomeness to their target. This may be used both offensively (a monster might be hit with such a pure wave of awesomeness it becomes a fez. why a fez? because fezzes are cool) and defensively (wouldn't you consider it awesome where the dragon flame that's about to burn you suddenly becomes a river of candy?). Naturally the more awesome someone is the more awesome their magic power is. Almost everyone has a little bit awesome in them, but not dave (lowercase d because he's so boring that even his name lacks any strength of character). dave is so boring and plain that he sucks the awesome out of everything and everyone near him just by being there to the level no awesome magic can happen near him. ### The question Why would a group of awesome magicians keep dave near them during their D&D-style adventures? Not just sorta be OK with him making their magic fail but actively want him around? It can't be that he's cool and fun to be around because that would mean he has some awesomeness in him, which is clearly false. ### Edit [At long last I made a short story inspired on this question](https://www.reddit.com/r/HFY/comments/efmllc/the_tale_of_dave/) [Answer] I've got a slightly different take on this; awesomeness isn't really awesomeness unless someone who's observing is... well, in awe of what they're seeing. Dave is a catalyst; pure and simple. Without dave in the troop, their acts are awesome, but to each other they're just... Normal. Almost like dave. They can all do as much 'awesome' as each other, so compared to each other, they're just plain. Compared to dave however, they're (you guessed it) awesome. This is why they need dave specifically; dave is SO plain, that to him even the simplest piece of awesomeness is awesome, meaning that he acts as an amplifier to this magic. Without dave observing and being constantly in awe of them, their magic is reliant on external observations, which is going to be patchy at best. If they're performing in front of other seasoned magicians, their awesomeness is reduced by virtue of the fact that the expectations are higher. So, dave is a critical part of their magic because when you get right down to it, awesomeness is something that is generated by the observation and comparison of external parties; it's subjective and therefore the observer has some influence on the amount of awesomeness generated. Sure, dave may 'suck the awesomeness' out of things near him but he's not an active participant in the magic, he's a passive observer and as such amplifies the awesomeness through observation, not reduces it through participation. In short, he's a catalyst in the true scientific sense of the word and let's face it; you could swat a fly in front of him and dave would be in awe. [Answer] ## dave is Family Maybe something boring like a step-nephew. dave is family for several of the awesome magicians, maybe most of the party. dave really wants to be here. And, dissing family is NOT Awesome. So... ## dave has Always Been There Everyone has their awkward childhood. Before the magicians were awesome, dave was with them. As kids, they played together on great adventures (dave usually played the imprisoned prince/princess, a role he never complained about). After the magicians were awesome, dave has been with them the whole way. Maybe they hope they can help dave find his awesomeness, taking him out on adventures despite the extra danger that creates. Maybe dave is beyond hope, but he's still there, and they can't bring themselves to break up the band. ## dave is Reliable When you leave dave to cook, the magicians can rely on him not being approached by a strange wizard with a magic ring, or a time-travelling phone booth arriving containing an old man telling dave that only he can save the future. When the magicians get back from their adventures, dave will be at camp, with a meal prepared and their stuff looked after. [Answer] ## dave's a good cloaking device The problem with being so super awesome is that you emit very distinctive waves of awesomeness, which makes it easy for the Government and other dullards to find you and ruin everything. The easiest way to cover up your signal is to bring along someone who emits the oppositely phased wave of dullness, thus canceling out your distinct awesomeness pattern. In other words: [![wubba lubba dub dub!](https://i.stack.imgur.com/lDkWu.jpg)](https://i.stack.imgur.com/lDkWu.jpg) Since the proposal is that awesomeness itself is a force, it would be easy enough to say that "canceling out your awesomeness pattern" inherently implies interference with utilizing that awesomeness. You could even work in some local deviation if you don't want total cancellation near dave: there are higher moments in the wave functions that aren't canceled perfectly locally, but at long range these (exponentially) decay and leave a nicely canceled wave on what's left. Long range invisibility at the cost of a bit of interference. Not a bad price to pay if your enemies are threatening or annoying enough. [Answer] > > Awesome people have the ability to perform awesome magic due to channeling their inner awesomeness to their target, this may be both offensive (a monster might be hit with such a pure wave of awesomeness it becomes a fez, why a fez? because fezzes are cool) and defensively (wouldn't you consider it awesome where the dragon flame that's about to burn you suddenly becomes a river of candy?). > > > Well, boring people people have the ability to perform boring magic due to channeling their inner boringness to their target, this may be both offensive (a monster might be hit with such a pure wave of boringness it falls asleep) and defensively (wouldn't you consider it boring where the dragon flame that's about to burn you suddenly becomes a wave of chamomile tea (thanks @algiogia, a blackboard with a bunch of math, or a pile of papers on a random boring subject?) I mean, you stop seeing the awesome dragon fire and instead become tired/bored just by looking at the blackboard. This would make your awesome magic/dragonfire become less powerful Of course, Dave does not have control of this boringness, it just pours out of him, so the awesome magicians cover him in a blanket so no one can see or hear him, then throw him at the monsters using their awesome magic. [Answer] # dave is practical He's really useful to have around in his own right. Left to themselves, awesome people tend to eat meals like fish fingers with custard, Dave can cook. He can put together a three course meal from things found in the woods. Dave can fix the wagon, mend a backpack, he finds washing up relaxing. It's like having your mum along on your adventures without having to have your mum along on your adventures. # dave is insurance If one of the group goes off the rails and needs to be suppressed, Dave is there to get things quickly under control without it turning into all out magical war. but more importantly # Being awesome all the time is exhausting When they go back to camp they want to relax without unexpected magical outcomes. Dave's ability to suppress magic allows them to drop their guard and unwind without consequences. Dave's aura of sheer unadulterated boring means that nothing exciting at all happens around him. The camp is never attacked, they're never ambushed while travelling, they never get lost, it never even rains too hard. All that would be too exciting to happen around Dave. While Dave derives quiet pleasure from a walk in the country. Adventurers actively seek out his company during a hard campaign to allow a few hours or days to recover. [Answer] Because he can absorb or dispel attacks from other awesomeness powered magic? Because often their magic goes out of control and Dave stops that? Or perhaps awesome magic leaks out unintentionally and Dave prevents it. Perhaps there’s a risk of accidentally performing magic whilst they’re asleep if they have an awesome dream, and so for safety powerful awesome magicians need to keep a Dave around at night? [Answer] # dave's boringness can be used to counteract dangerous magic. In most combat scenarios, dave is an irreplaceable asset for the party. While the awesome magicians can channel their awesomeness into al sorts of useful magic, they also face the danger of dark wizards channeling their evil awesomeness and threatening the entire party. However, dave is *so incredibly boring*, that any dark magic that the wizard tries to conjure up (using his awesomeness) is completely absorbed by dave's utter boringness. All dave has to do is step out in front of the party when they face a magical type of danger, and his incomprehensible lameness actually becomes very useful. Basically, dave is a powerful shield that counteracts any awesomeness-fueled offensive magic which comes near. When it comes time for the party of awesome magicians to use their power to clear away a blockade or eliminate a threat, dave simply needs to fall behind to the back of the party. [Answer] ### Because the awesome magicians are not "that awesome" Or, our heroes know they have weaker magic then their enemies so they plan for it. Imagine this in D&D terms: You are going to fight a high-level boss or party. They are awesome, buffed and ready to grind you into the dirt. What is your first move? **[Dispel their magic](http://www.giantitp.com/comics/oots1122.html)** So our hero's use this trick in two ways: 1. Send in dave first. So you have a dungeon filled with giant acid spewing lizards, huge deadly spiders, and horrible orcs? dave just walks through it and absorbing all the awesome magic leaves only the original tiny lizards, normal spiders, and what turned out to be cardboard cutouts. Your party now just has to walk through this now unguarded basement and do what they need to (their magic now working because dave is out of the building). Yeah the original wizard can re-setup his magic but its going to take time and that time gives a huge advantage to our party. 2. Fight physically weaker enemies with dave in the active party. You have awesome magic!!! Why work out? Why buy "real" weapons? You can buy this cool plastic replica sword and cast your magic to make it a +7 Vorpal Blade and buff yourself to Olympian strength and flexibility.....Except dave is here and now you are an out of shape guy, holding a piece of plastic. While our party is carrying their ordinary steel knives, swords, crossbows & wearing real armor. As long as dave is there you can't rebuff and our heroes have a pretty decent advantage :) [Answer] ## FOMO Awesomeness is awesome when you’re ready to party, but when you want to sleep, you want a bit less excitement. Maybe these boss-level magicians are so awesome that random cool stuff happens while they sleep. Imagine the **fear-of-missing-out** that these beings would suffer: they sleep through being attacked by a dragon whose breath weapon turns into a candy flow... and when they wake up, all they know is something really neat happened, but they didn’t see it! So they keep dave around. Now their nights are perfectly normal. When they need magic, they have dave put up a billboard advertising just how awesome dave is as a magic dampener, which is enough external excitement to prevent him from dampening anything other than himself (which is even more pathetic, if you think about it). At end of day, take down the advertisement. [Answer] ## Dave reminds you what it means to just be alive An awesome world is great, but it's so easy to get saturated. I mean, when the world is so awesome that bow ties are cool, pretty much everything starts to look the same -- awesome. Enter Dave. Around Dave, you have to fight for survival. A 50 foot cliff? No problem, I'll just featherfall down, or turn the ground into golems to carry me down. Oh, I'm with Dave? Oh. This 50 foot cliff is *actually* 50 feet. There might not be a way out of this. There's nothing like jumping out of a perfectly good airplane to remind you how much you appreciate your parachute! "Stop and smell the roses" they say. Well, when you can channel a field of them without even trying, frankly, they stop smelling so sweet. But picture this. Your rations are running low. You just narrowly avoided death at the hands of the dreaded ice kobolds. You're running on awesomeness and prayers, and that awesomeness isn't there for you. Then, you see a rose bush. Just one. A wild rosebush. No magic there. This is the real thing. This is worth stopping for. You may have seen Penn and Teller's *Fool Us* show. It's a great show, but the show misses out on something important. Each time, before the show, Penn and Teller explain why they're doing the show. (Okay, fine. Penn explains it. Teller looks emphatic.) Penn explains that he got into magic when he was just 5 years old. There was a certain sparkle that magic had for him. Something truly wondrous. Well after several decades in the business, they've seen pretty much every magic trick out there, and they know how they are all done. And somewhere along the way, the awesomeness went away. So they do this show, hoping that *one* act will spark that five year old's wonder that they are missing. That's why they keep doing it. And, every now and then, [they actually got the wish](https://www.youtube.com/watch?v=CRpz0zuAGVs). [Answer] If I were Superman, I would want to know where every gram of Kryptonite in the whole universe was, to avoid unpleasant surprises. In a like manner, if you leave Dave at home because he's too much of a bummer, then when you go up against the Big Kahuna you run the risk of finding that the BK has turned Dave against you in some way. [Answer] ## Fezpocalypse Without dave around to buffer the effects of all that awesomeness floating around a single party, the awesomeness would bounce off and multiply against everyone else's awesomeness and cause an awesomeness feedback loop that could turn everything all around into fezzes. All the trees, buildings, people, as far as the eye can see. Nothing but fezzes. Mountains in the distance would turn into great big fezzes in the distance. Clouds would turn into fezzes and come falling down to the ground. Maybe even the earth would turn into a tremendous fez and the party would find themselves standing on a completely featureless flat red surface. Or the party turns to fezzes too, except dave, the last surviving non-fez. [Answer] **The wizards inexplicably idolize Dave**: This may not seem like the most obvious, plausible, or clever reason, but in light of your story, I think it's by far the *funniest* option. The wizards know Dave is bad for them, and any objective, third-person observer can tell them that Dave is a complete wet blanket, with no discernible redeeming qualities, but every single wizard thinks he's the coolest thing ever. They hang on his every word, they laugh at all his horribly unfunny jokes, they take his banal opinions as golden proclamations, and they all want to hang out with him all the time, even though they know they shouldn't For maximum comedy, Dave should barely tolerate the wizards, even though they are the most awesome people in the universe, and he's a boring, obnoxious pain. [Answer] Left to his own devices, dave go into a runaway negative-awesomeness feedback loop, finally collapsing into an de-awesomeness singularity. While this would be awesome to watch, it would also, by it's nature, be able to fit any awesomeness inside, for a net zero awesomness. So, not awesome. The wizards are saving the world by socialising with dave - which makes them awesome. [Answer] ## They want to find dave's Hidden Awesome As the first non-awesome person anyone's ever met, they're all convinced he has some secret reserve of awesome, and once the right awesome events happens to (or maybe just near) him his awesome powers will reveal themselves. ## Be Awesome to each other Additionally, part of being an Awesome Magician is being awesome to everyone, including those who (unintentionally in dave's case) harsh your awesome. These wizards have banded together to help prevent the ostracization dave has suffered at the hands of the only "slightly awesome, but not woke awesome" regular populace. [Answer] ## As defence from other awesome magicians There are awesome people in the world. But awesomeness is relative. They may be awesome, but these guys who hang out with dave are more awesome, which makes the other magicians less awesome. So if they could get rid of daves magician friends, they would become more awesome. But daves magician friends are more awesome, so you will have to attack them by surprise. But then, there's dave. The ultimate shield against all awesome. No matter how many awesome magicians have tried to ambush the part, the giant meteor of rock (candy) that's meant to crush the awesome party and dave, simply ceases to exist when it gets too close to dave. Noone quite understands this power, as a matter of fact, they think the awesome part is so awesome their awesomeness just erases all others. After all, dave is so boring his name is lower case, how could *he* ever possibly be awesome enough to overcome awesome magic. Or perhaps even Dave is the one who defends the magicians, attacking the 'awesome' people who only attack with a handful of sticks etc. that they use their awesomeness to change into amazing weapons. But awesomeness doesn't work near dave, so they are suddenly defenceless, and dave simply stabs them with a real sword. Then again, that could make dave actually quite awesome. [Answer] Anything related to a prison or prisoners. Obviously dave would make a great prison guard as the prisoner wouldn't be able to use magic to escape. Prisoner transport, again the prisoner can't use magic and anyone who would try to aid them from escaping couldn't use magic. Quarreling wizards who hate, dislike, or etc each other. Boom wizard 1 can no longer turn wizard 2 into a toad because of some offense real or imagined. What if your a wizard who has nightmares and starts casting spells in your sleep. You and all the members of your party would definitely want this anti-magic person. Medical core would want one in case a wizard start hallucinating and trying to cast spells against things that aren't real. An anti-magic person would be a real boon in a mental ward to prevent wizards with Alzheimer's and other disease of the brain. [Answer] Having Dave around would allow them to pass as non awesome people for purposes of deception to potentially hide how strong they are or to sneak into a place protected from awesome people. [Answer] **dave doesn't negate their power, he *causes it*** How about dave is antimatter? as in, he doesn't sap the awesome magic, but is, in fact, the negative counterpart of the awesome magic. IE, the existence and proximity of dave is exactly what causes the awesome magic. Kind of like two magnets next to each other. Snap them onto each other, nothing much happens. Pull them too far apart, nothing much happens. However, keep them juuuuuust close enough, but yet juuuust far enough apart and all sorts of fun things happen... [Answer] # `dave` is an obligation. In other realms, a wizard may be tasked with raising a young prince for their duties as the one true King, but one of your awesome wizards has been lumped with the task of protecting the `dave`. If any evil ever befalls `dave`, there are catastrophic consequences (such as all fezzes becoming "kiss me quick" hats). [Answer] They owe dave a life-debt. At some point dave saved their lives by being present during a magical event that would have killed them. Until they save dave's life, they need to keep him around so they have the opportunity to repay the debt. Of course, because most of the danger in the world is magical and dave is so boring he cancels out the awesomeness-based magic he always ends up saving himself by cancelling out the awesomeness. [Answer] Wow didn't expect this silly little question to get so much attention... thanks for everyone, you truly are awesome. Thought about it quite a bit and while the answer I like most was the one @John suggested at the comment section about them hanging with him do to it being the awesome thing to do I'm going to go with a different route, apologies in advance if some of you feels like I'm bending the question rules with this answer but I feel that this twist to the story is too awesome not to use (couldn't have figured it out without you). dave isn't awesome... or is he? if he's just a catalyst for other people awesomeness or the baseline 0 awesomeness other people are measured by then that kinda makes him awesome,if he's just really reliable and always been there then that also makes him awesome. In fact just about every reason covered by the answers given (which are all awesome don't get me wrong) also seems to make him just a little bit awesome when you think about it... awesomeness clocking device? just being named that is awesome... anti villein awesomeness secret weapon? secretly awesome... allow the awesome magicians to relax from all the awesomeness? everybody needs some downtime and giving somebody a well deserved rest is awesome... even having boring magic is awesome because since when is magic not awesome? So if dave is somewhat awesome how can he suck the awesomeness out of everyone and everything around him? like @Tim B II suggested awesomeness is only awesome when measured on a scale of awesomeness and dave well... dave breaks that scale... he isn't drowning out the others awesomeness due to being so boring... he's secretly the most awesome thing to have ever existed and anything else ceases to be awesome near him. Why nobody knows it about him and why everyone think he's so boring you ask? the reasons are tri-fold: 1. Because he's confident enough not to brag about your abilities is the awesome thing to do. 2. dave hiding is awesomeness is the form of playing the long game, preserving the element of surprise should the situation ever become dire enough, and planning ahead is a sign of an awesome individual. 3. dave is effectively allowing the other magicians to discover their inner awesomeness like @John suggested by hiding his much more powerful awesomeness and the only way he can do that is by self sacrificing (again awesome) every bit of reputation he would get had he showed it's true awesomeness. and why lower case "d" in his name? dave gave the upper case to charity... he's so awesome he can literally give letters to charity, and being an anonymous donation his secret is still safe. [Answer] **Every one needs a boring side.** Most adventures are a lot of boring tasks. Getting the fire wood and checking the map, discussing the new government of the land you freed, allocating budgets for different adventures.... the list goes on. It's hard to deal with practical matters when you are busy being awesome. Fixing a trailer to the sports car you purchased to hunt a dragon in the desert is not awesome, running out of supplies and having to call for help is much much less awesome. [Answer] Performing awesome feats while being slowed down by someone boring makes it more difficult, thus success would be even more awesome. This leads to bonus awesome (XP) afterwards. Kind of metagaming.. [Answer] **Because hanging around Dave is awesome**. Obviously, mages would need some way to cast magic despite Dave's anti-awesome aura: they may need to get some distance away from him, for example. But when they *can* use their magic, the fact of their continued association with him actually *strengthens* it. So, why is hanging around Dave awesome? There are many ways you could play this. Maybe it's because it's badass to hang around with your one weakness nearby, where anyone could use it but you're confident in your ability to beat them even despite that. Maybe you hang out in the border between the awesome world and Dave's anti-awesome world, and living on the edge like that is awesome. Maybe he's just a really good friend, and you like to have him around even though his limitations sometimes cause trouble through no fault of his own, and sticking by someone like that is awesome. [Answer] **dave is a Safety Release Valve/Storm Drain/etc.** In this world, one's magic is powered by their inner awesomeness, rather than your apparent awesomeness; your magic isn't determined by how others view you, but is an intrinsic property of your personality, your very being. This has the logical effect that your magic depends on a property that is always active, due to being a defining part of who you are; it's similar to magic power being determined by how red one's hair is, or by the colour of one's eyes. As such, it's entirely plausible that some magicians may [not be able to control their magic](https://tvtropes.org/pmwiki/pmwiki.php/Main/PowerIncontinence). This is where dave comes in: Since he's so boring that no awesome magic can happen near him, he by definition enforces absolute suppression over all awesome magic. If any mage has trouble controlling their awesome magic, which most super-powerful awesome mages likely would by very nature of the magic simply being the outwards manifestation of their personalities, then dave can easily function as a safety system to control when and how their magic can be used. This is somewhat similar in concept to, e.g., Superman giving Batman a chunk of Kryptonite in case he needs to be stopped, or Cyclops wearing a visor/sunglasses to let him choose how to use his eye beams instead of just spewing them everywhere at all times. [Answer] dave is an autonomous, continuously firing, anti-magic bomb. Whose enchantments did you want to break? dave's your guy. Whose Earth-shattering kaboom needs thwarting? dave's your guy. Inadvertently summon [redacted to preserve sanity] and need it dispelled? dave's your guy. dave: 1001 uses. [Answer] Dave is a pretty cool guy. That and you don't want Dave to be evil. Who else is better insurance against an evil Dave than 5 awesome magicians? [Answer] breaking friendshit isn't awsome. and if you do it just to be more awsome then you are a jerk, and there is nothing about jerk who try to be awsome that is actualy awsome so this group of awsome mage are either to awsome to thinking about breaking up with dave, or, they are aware that they can't just dump him without just saying "you ain't awsome bro" [Answer] **dave is penance** True awesomeness comes with responsibility. To preserve their humility and promote empathy all truly awesome practitioners must do penance by having their magic blunted, and do it willingly. It is the path to enlightenment (or say, the path to touring Mars with Wyld Stallyns). ]
[Question] [ ## Premise Mars has been terraformed and has seen its first few stages of large-scale colonization. The colonists are middle to upper class Earthlings. Earth is not a dystopian planet per se, but Mars offers great air quality, job opportunities and more. The population on Mars is now very heterogeneous and the government is a very egalitarian / pluralistic one. The decision has been made by the Mars government to allow the private sector to build religious structures as desired. However, this task is some what tricky. First consider the original passage concerning qiblah (direction of prayer): [![enter image description here](https://i.stack.imgur.com/hRMrS.png)](https://i.stack.imgur.com/hRMrS.png) It reads: > > We have certainly seen the turning of your face, [O Muhammad], toward > the heaven, and We will surely turn you to a qiblah with which you > will be pleased. So turn your face toward al-Masjid al-haram. And > wherever you [believers] are, turn your faces toward it [in prayer]. > Indeed, those who have been given the Scripture well know that it is > the truth from their Lord. And Allah is not unaware of what they do. > > > In this case "wherever you believers are" takes on a whole new meaning. ## Question Are there any viable techniques to help the Muslim Mars colony to choose a proper area such that the qiblah ontology is satisfied? The reason I said it's tricky earlier is that Mars and Earth both have their own orbits and rotations. I would like to see something like the following in the answers: Some physics concepts to explain why / why not the mosque site is arbitrary **Bonus:** If you want to go the extra mile, try including these in your answer: * In the case of the mosque site not being arbitrary, what is an example "good candidate site"? (perhaps martian coordinates?) * In the case that the mosque site is arbitrary, what else could the Muslim mosque colonists try to justify a deserving plot of land? **Further Clarifications:** * The believers: the Muslim colonists on Mars * The qiblah: the direction facing Mecca, on Earth * technology: assume the mosque is traditional, but the colonists can use near-future technology in the design and construction of the mosque (they already have terraforming) * Success metric: the mosque on Mars faces the correct qiblah **OR** the mosque site faces the qiblah *more often* than other places on Mars. [Answer] Islam is a religion with as many varied views as any other major religion. There is no correct answer, for different clerics will have different interpretations of scripture and for their respective communities, they will each be right on their own way. There are many possibilities for interpretations, but I will just add two: one from a known source that has already had a say in such a matter, and one of my own. Disclaimer: I am not a muslim, and asides from some books and a few friends I've had little to no contact with the muslim faith. # The practical solution already employed [I found this interesting answer about praying outside Earth, on the Islam site here in SE](https://islam.stackexchange.com/a/17615). Turns out there have already been plenty of muslim astronauts in space before. The link contains the whole elaboration, but the part I wish to quote is an actual interview with one such astronaut, with emphasis of mine: > > MARTIN: One of the aspects of space travel that I think people find fascinating is how astronauts cope with the routines of daily life, be it eating or brushing their teeth. And traditionally, Muslims are required to pray five times a day. How did you address this responsibility while in space? > > > SAUD: Very easily. Because we have been acclimated, whether from a religious point of view or whether from just a personal point of view, I myself have grown up in the central part of Arabia, and we're surrounded by great deserts. And, of course, I'm a diver also at the same time. And I'm a flyer and I'm a glider pilot. And in doing all these things at the same time, they become natural when you work on them and practice them. > > > **We never really saw Islam or religious duties as being something out of the ordinary. I remember, you know, whether we're flying or in different places - as a Muslim, you can pray anytime. You can face any direction. Like, in the space shuttle, you know, we can't really face to Mecca, although we're flying east, because we're flying at such a great speed. Like I said, those days, by the time you face Mecca, you probably already passed it**. > > > MARTIN: **So what did you do? Just stop or - how did you manage it? You couldn't have a rug, I presume**. You couldn't have a prayer rug. > > > SAUD: No rug. No magic flying rugs. > > > MARTIN: No. > > > SAUD: But, you know, I had to strap my feet so I can kneel. You know, you can't kneel fully because lack of lack of gravity, actually. But, you know, **I prayed like a traveler**. As travelers, we pray three times a day, not five times a day. And I prayed according to Florida time, when we launched. And, in fact, it was the end of the fasting month, which is approaching now, as you know, in about three weeks. > > > TL;DR they seem to go with the best effort option. Just like a man without legs will not be considered sinful for not kneeling down, so won't a man who is unable to face Mecca in a practical way be considered sinful for praying as best as he can. # The most probable thing in the future, though Sols in Mars last almost as much as a sol in Earth for all practical purposes, which works quite in favor of any muslims who happen to live on Mars in the future. Given the state of geolocation we have today on Earth, it is no stretch to imagine that geolocation would be just as good, but probably better on Mars. **A simple smartphone app or whatever equivalent people use in the future will should be able to point the faithful in the right direction.** A GPS antenna, a gyro and a compass together will currently fit in your hand and have been things for decades now. The mathematics involved are a little rocket-sciency, but nothing that a computer science undergraduate could not implement in a couple days. Moreover: mosques on Mars could be built in such a way that there will be indicators on which way you should face while praying, which will vary slightly during the course of a day. This variation is cumulative, so the changes will be mostly perceived throughout the year. --- Going an extra mile here. At some points during both planets orbits, the Qiblah might be "above" or "below" the faithful when they are in the Mosque during prayer time. This will happen mostly around the equator, for the inclination between the orbital planes of the Earth and Mars is very small (less than 2 degrees) - and then again, not throughout the whole martian year but rather a small part of it. For example, Isha (a prayer that begins before the midnight) when Mars and Earth are at their closest. Mosques on higher latitudes will not have this problem, and in fact should be able to face the Qiblah everyday, specially above 45 degrees north, or below 45 degrees south. For the mosques closer or around the equator, you either wait a little longer until the geometry allows you to face the Qiblah properly, or (as per a comment by [Jay](https://worldbuilding.stackexchange.com/users/2973/jay)): > > The "straight down" problem occurs here on Earth too: For a Muslim in Rio de Janeiro, Brazil, Mecca is just about straight down. but they don't go by the straight-line direction, they go by a great circle direction. > > > So in the future, muslims on Mars might face the horizon, turned to the direction in which the Qiblah is closest. [Answer] ## Other than actually going to Mars, we can already do this. Build each Mars mosque with a round prayer room and with a domed roof. Set the space up like a modern-day [planetarium](https://en.wikipedia.org/wiki/Planetarium), complete with projectors or equivalent technology. (Note that the link references inflatable, portable, planetariums, so this concept could be "packed" aboard a colony ship in deflated state, if need be.) (See [Hagia Sophia](https://en.wikipedia.org/wiki/Hagia_Sophia) for an example of a domed structure that began as a Christian church, became a Mosque, and is now a museum. As an aside, I've toured this building, and it is an unbelievably awe-inspiring structure.) Computers can easily calculate the exact position of Earth relative to the GPS coordinates (or preset location) of the Mosque. At prayer times, the computer generates a symbol for the planet Earth, then projects this symbol in the appropriate location on the ceiling. If the Earth is below the horizon at that time and from that Mars location, it would simply show an arrow at the appropriate spot along the lower-most ring, to point where the Earth is, "off screen" to those in prayer. **We have 100% of this technology already.** We use it in planetariums to recreate the night sky for any given Earth location and time. I've seen Mars in these projections a number of times. It would be trivial to reset the calculations to show Earth *from* Mars. And it could update the location in real-time all day, every day, if need be. [Answer] Correct me if I am wrong, but I read as "the prayer has to be properly oriented". This means that, as long as the prayer is aiming at the Earth, and this is easily doable knowing where it is in the sky at the moment of the prayer, the condition is satisfied. Mind that, given the relative distance of Earth and Mars, the position of the target with the rotation of Earth won't change appreciably. [Answer] The best solution I can think of would be to have the mosque contained within a sphere that would always orient itself properly. If you have some sort of artificial gravity, then the mosque would be properly oriented even if it had to face itself downward through the planet, if need be. [Answer] Have a mobile [qibla compass](https://en.wikipedia.org/wiki/Qibla_compass) in the mosque. The colony will be very interested in pointing radios at Earth so will keep a reliable method of keeping the direction updated. Linking the aiming of the radio to the rotation of the pointer should be easy. But also the planets change angles fairly slowly and in a predictable way with conjunctions just over 2 (Earth) years apart. A calender or almanac could be made that would give the direction to earth on any particular day or month. Since the local (Mars based) calender and the (Earth's) moon based Islamic calender would be already hopelessly out of sync adding a third for direction finding wouldn't be a huge issue. [Answer] **You've asked for a physics answer to a religious question** I enjoyed reading an explanation of *qiblah* on [AboutIslam.net](http://aboutislam.net/counseling/ask-about-islam/significance-qiblah/). The article makes these points: > > 1. **Obedience:** Facing the qiblah is, first of all, a test to our ability to obey the commands of God even when we fall short from understanding His wisdom. Muslims, as servants of God, are required to surrender to Him. > 2. **Unity:** Another aspect is the fact that the qiblah is a sign of the spiritual unity of Muslims. At the time of prayer, Muslims all over the world are lined in circles big and small facing one direction and feeling belonging to this center and belonging to each other. > 3. **The Hajj:** On the individual level, it is well known that Hajj (pilgrimage to Makkah) is one of the main Islamic deeds and the fifth pillar of Islam. Muslims all over the world, who are not in Hajj, face Makkah five times a day to re-voice their wish and love to perform this great ritual of Islam. > 4. **Devotion:** Another important point, which I think very important today, is the fact that everyone in this world has a direction in his or her life, whether physical or spiritual. ... Only when people lose the direction, they face loss and disruption. Since Islam is the religion of monotheism and since Muslims believe that Almighty God is beyond space and place, above time and perceptions, we cannot face the heavens in our prayer because it is impossible, but we raise our hands seeking help from God. > 5. **Sacred:** Muslims face the Kabah because it is the first sacred house ever built for mankind, established by Adam and raised by Prophet Abraham. So, they connect themselves with these great prophets and renew this lineage that extends from Adam to Muhammad (peace be upon them all). > > > I suspect that after some initial discussion (might be outright arguments) a combination of practicallity and spirituality will prevail. **I suggest that on Mars (and every subsequent planet) would be built a single [*Makan Muqadas*](https://translate.google.com/#en/ar/sacred%20place) ("sacred place") that would symbolically represent Mecca as the first sacred house built on that planet.** This eliminates the confusion and impracticaility on each and every planet, the result being that all Muslims on every planet are doing exactly the same thing. Those with resources to complete the Hajj to Earth are fortunate, but those whose resources only permit an Hajj to *Makan Muqadas* are celebrated and accepted. [Answer] You realize, of course, that it is possible to build a building that rotates with modern technology? I imagine a circular or rectangular building with one or more domes and a *mihrab* niche, so the building can be rotated so that the *mihrab* always points in the direction toward Earth. And there could be a slot in the dome and in the *mihrab* niche in the walls with many sections of coverings that could be opened or closed so that there would be one opening in the slot centered on the dot that was Earth in the sky, or else pointed downward if Earth was below the horizon. On Earth Muslim prayers orient themselves in the direction to Mecca, and stand, sit, bow, and prostrate themselves face downwards during different parts of the prayers. If they are facing the direction of Mecca, they may have their eyes looking in the direction toward Mecca when standing up during prayer sessions, and then have their eyes looking downwards at about 90 degrees from the direction of Mecca when prostrate face down during prayer sessions. Since Mars orbits outside Earth, and since Islamic prayers are mostly during the daytime, Earth should always look somewhat close to the Sun during prayers. According to an answer to this question, the maximum possible elongation between Earth and the Sun as seen from Mars is 47.378 degrees. So even at maximum elongation and in the worst possible configuration Earth will never be more than 47.378 degrees below the horizon during Martian daylight, and it will above the horizon during daylight about four times as often as it is below. <https://answers.yahoo.com/question/index?qid=20091003012620AAxZKSP>[1](https://answers.yahoo.com/question/index?qid=20091003012620AAxZKSP) I point out that on Earth, the orientation of a mosque is determined by the line to Mecca along the surface of the Earth, which of course is a curved line and not straight, even when it is calculated correctly. Hypothetical mosques that are exactly antipodal to Mecca will be oriented so that the Muslims will be looking along a line that travels 12,000 miles in a semicircle to Mecca, while the actual direction to Mecca is straight down from the mosque 8,000 miles through the center of the Earth. By Muslim conventions, it is thus considered acceptable and usual for the mosque to be oriented so that the congregation faces up to 90 degrees away from the actual shortest, straightest, direct line to Mecca going through part of the Earth. The 5 times Muslims on Earth pray are between dawn and sunrise, preferably 10 to 15 minutes before sunrise, then after true noon, then in the afternoon, then after sunset before dusk, and then after dusk. If hypothetical future Martian Muslims pray during the Martian sol, or day, the Sun will always be over the horizon during the post noon and afternoon prayers. Since Earth will always be between 0 and 47.378 degrees from the Sun as seen from Mars, it can never be more than 47.378 degrees below the horizon during those prayer sessions. Suppose that the Sun is high in the Martian sky, over 42.622 degrees high, and the Earth is 47.378 degrees above the Sun. Then the Earth will be over 90 degrees high, and thus behind the congregation. So the mosque will rotate 180 degrees until it is facing toward the Earth and Earth is high overhead and the congregation is facing in the direction to Earth. During the dawn/sunrise and sunset/dusk prayer sessions, the Sun will be a few degrees below the horizon. If the Sun is X degrees below the horizon, and Earth is between zero and 47.378 degrees away from the Sun, the Earth can be as high as 47.378 minus X degrees above the horizon, or as low as 47.378 plus X degrees below the horizon. X should be only a few degrees, probably less than 10. What about during the post dusk prayers? Then the Earth and Mecca could be as much as 90 degrees below the horizon. But never more than 90 degrees. If Earth is more than 90 degrees below the horizon the way the mosque is facing, the mosque can rotate until Earth is less than 90 degrees below the horizon. On Earth Muslim prayers orient themselves in the direction to Mecca, and stand, sit, bow, and prostrate themselves face downwards during different parts of the prayers. If they have the horizontal direction to Mecca correct, their direction of vision will swing through about a 90 degree vertical arc several times during prayer that will pass each time through the exact direction to Mecca. If a rotating Martian mosque prayer hall is correctly rotated so that its *mihrab* niche is facing toward Earth and Mecca in the horizontal plane, Earth and Mecca can never be more than 90 degrees (straight up or straight down) away from the *mihrab* in the vertical plane. If Earth is exactly at the horizon during prayers, the congregation will face exactly toward Earth when standing and facing the *mihrab*. If Earth is below the floor, the congregation will briefly be looking exactly at Earth whenever they change from standing or sitting to bowing or prostrating themselves, and vice versa, and change the elevation they are looking at. If Earth is high up in the sky during prayers, the congregation might not look exactly toward Earth during the prayers. And to avoid that, some Martian Muslims might hold mirrors at an angle and look up at the dome in the mirrors during part of the prayers. Or some Martian Muslim congregations might add to the prayer ritual a moment of looking upwards, even if it hurts their necks a bit, at the position of Earth. Thus a Martian Muslim congregation, in a rotating prayer hall correctly aligned, can never be looking more than 90 degrees away from Earth, Mecca, and the Kaaba. And an Earthly Muslim congregation, in a stationary prayer hall with the *mihrab* pointed at Mecca, can never be looking more than 90 degrees away from Mecca and the Kaaba. So as far as I can tell a horizontally rotating prayer hall on Mars would enable Martian Muslims to face in the direction of Mecca just as accurately as Muslims on Earth do. Except that on Earth the line to Mecca is never a straight line directly to Mecca but always a curved line arcing along the surface of the Earth, while a line from a Martian mosque to Mecca on Earth would be a straight line. Thus hypothetical Martian Muslims might consider Muslims on Earth to be some sort of heretics who don't pray correctly, and might invade Earth and force all Muslims on Earth to move to Mars so they could pray correctly, never being allowed to return to Earth except on pilgrimage to Mecca. Of course the larger a building is, the harder it is to make to make it rotate. Thus a Martian mosque for a large congregation might have to have many different prayer halls that rotate separately to keep lined up with Earth and Mecca. Here is a list of some rotating buildings: <https://weburbanist.com/2008/09/20/rotating-architecture-16-sweet-spinning-structures/>[2](https://weburbanist.com/2008/09/20/rotating-architecture-16-sweet-spinning-structures/) I note that each of the 11 floors, each with a single apartment, in the Suite Vollard, built 2001, in Curitiba, Brazil, rotates separately from the other floors. <https://www.emporis.com/buildings/136410/suite-vollard-curitiba-brazil>[3](https://www.emporis.com/buildings/136410/suite-vollard-curitiba-brazil) A hotel planned for Dubai, scheduled to open in 2020, will have 80 floors with an apartment in each separately rotating floor. <https://www.news.com.au/travel/travel-ideas/weird-and-wacky/dubai-is-planning-the-worlds-first-fully-rotating-skyscraper/news-story/11b2f45c2137ac2bcd114c6b89ec7059>[4](https://www.news.com.au/travel/travel-ideas/weird-and-wacky/dubai-is-planning-the-worlds-first-fully-rotating-skyscraper/news-story/11b2f45c2137ac2bcd114c6b89ec7059) Wikipedia has a list of rotating restaurants subdivided into list for 69 countries. > > The following is a list of revolving restaurants. A revolving restaurant is usually a tower restaurant (an eating space) designed to rest atop a broad circular revolving platform that operates as a large turntable. The building remains stationary and the diners are carried on the revolving floor. > > > <https://en.wikipedia.org/wiki/List_of_revolving_restaurants>[5](https://en.wikipedia.org/wiki/List_of_revolving_restaurants) Or possibly most of the building structure would be solid and unmoving, but a strip of wall perhaps ten meters tall, would be transparent, supported by widely spaced steel columns, and an inner opaque ring of wall just inside it would rotate so that the only transparent section of the wall, with architectural framing like a niche, would face toward Earth. That might save on the weight of structure that would have to be moved. And of course legend tells of the amazing *Takht-i-Taqhis* built by Khusrau II, King of Kings of Iran, (reigned AD 590-628) which had a dome that revolved like the heavens, and the entire building could be turned in various directions. And then there was Nero's Golden House. Seutonius, in his life of Nero, # 31 says: > > The main banquet hall was circular and constantly revolved day and night, like the heavens.9 > > > <http://penelope.uchicago.edu/Thayer/E/Roman/Texts/Suetonius/12Caesars/Nero>\*.html[6](http://penelope.uchicago.edu/Thayer/E/Roman/Texts/Suetonius/12Caesars/Nero*.html) And archaeologists discovered what could be the foundations of the revolving room in 2009. <http://www.ancient-origins.net/news-history-archaeology/revolving-dining-room-emperor-nero-s-luxurious-palace-really-existed-001824>[7](http://www.ancient-origins.net/news-history-archaeology/revolving-dining-room-emperor-nero-s-luxurious-palace-really-existed-001824) So people have been working on the design of revolving structures before the first mosques were ever built, and for two thousands years before the probable date for the first colonization of Mars. [Answer] I'm thinking the first Mosque on the planet will hold special significance to the religious community. Once the community is fully established and has time they would be able to build a huge place of worship that has all designs worked into one. I refer to this as the Main Mosque. I see three options that can be combined: 1. You have the main mosque that has a rotating inner sanctum that always faces the intended direction. I can't see the feasibility of a rotating building being justified by colonists or architects/engineers. They can however have the mosque designed with a general foyer floor. Then a staircase to elevate you above your earthly or martian worries. On the First Floor, you have a rotating room. The building's outside walls remain stationary and the first floor rotates around the staircase, with a set of 'inner' walls. These walls can now be decorated in whichever way is traditional for various Mosques. The walls will rotate so that the direction of prayer is always clear. 2. The main Mosque provides direction for Martian prayers. Not saying pray to the Main Mosque (that could be an option if necessary), but rather the Main Mosque can provide an indication of which direction to currently pray in. Linking back to the direction that the main floor of the Mosque is pointing. I'm thinking a visual device. Something like a large three dimension wind-vane type device on top of the main Minaret (highly decorative and stylised of course). People can look at the main mosque and easily see which direction to currently pray in. This can be updated with technology, so that the directions/co-ordinates can be broadcast across the martian landscape. 3. Orient the Martian Main Mosque to Earth's Mecca for a day of special significance. Choose a day of extreme significance to the religion. Either on Earth, or maybe day of first Muslim arrival on Mars (your choice). Orient the Mosque so that the main building is fully orientated to Earth. Smaller/newer mosques can either orientate themselves in relation to the Main Mosque, or on their own choice of day of significance. You could possibly have a series of Large Mosques that celebrate different events. Martian Hajj, could be to make a pilgrimage to pray at the various orientated Mosques for each of the main events during the religious months. --- Extra notes: * Also take into account the different planetary Calenders. 685 Martian days vs 365.25 Earth days. You would find this affects your story as well. * Some years, Earth will be closer to Mars, and some years will be further away. This will probably play into the developing Martian religion. Making prayers at specific Mosques which are closer to Mecca could become an important part in Martian Muslim Culture (mountain top Mosques may also play a more important role). [Answer] For a maximum effect, to make sure that it *is* the Martian year's most precious day, build a laser inside the Mosque. One day a year, the laser will hit a precise point at the Mecca. That will be the day of spiritual rejoice, the believers will feel united to their brethrens on Earth as their own laser will hit the Mosque's. This will be the mark of a special, all new celebration to remember truly the Muslim roots of those colonists. During the rest of the year, I guess, but not being a Muslim myself I cannot give a precise answer, it will be enough that they pray in the direction of Earth, during daytime. Even better when dawn or twilight are upon them so that the mother planet is visible in the sky though for an even more limited time. Muslims who really don't want to go all the way will just accept to pray in the direction of a position on Mars with coordinates similar as to the Mecca's on Earth. I feel pretty sure the Imams will sanction it. [Answer] 1. The mosque could have a special room that spins, using centrifugal force to keep everyone pressed to the wall. It then points towards earth (Mecca, if you have a really, really precise laser). It work based on the same technology as these theme park rides, but probably less barf-inducing: <https://www.youtube.com/watch?v=KLy8AM6-jJ8> <https://www.youtube.com/watch?v=KniIDFdyQnE> 2. the Martians could break of a chunk of the Kaaba rock and bring it with them to mars, then they could all pray towards that. 3. Martians don't think much of earth religions, and persecute believers. Of any religion, or specifically Islam, if it fits your story. Muslims on Mars must practice Taquiya, exempting them from that particular rule. [Answer] This matter has already been discussed long ago by Muslim scholars and the issue actually has a pragmatic solution. **The mosque** Can be anywhere on mars! There's no restriction. One may consider to build a round or circle-like mosque due to what I will explain next! **The qiblah direction** This actually is the issue as each time you pray you need to face -at least for the beginning of your prayer- the correct direction, which in this case is the actual direction of earth (according both Shi'a and Sunni Scholars). As the Ka'abah or al-Masjid al-Haraam are on earth and facing the actual position of the Ka'abah is rather difficult and therefore a deviation is allowed. Note that even on earth a deviation from the qiblah is allowed in case of necessity or incertitude. Else I bet most mosques around the world should have been rearranged after the introduction and use of GPS. Actually I know two mosques in the same district in Salé Morocco which point to somewhat different qiblah directions I'd say that the deviation angle is of > 25°, it even happened that people outside the mosque missed the qiblah direction of the mosque by around 45° at Friday's when the mosque is too crowded. So basically what you have to invent or make sure is that each mosque on mars has a device that can point at the most closest point on earth at the actual prayer time (maybe a GPS is already sufficient or a kind of compass pointing at earth). **Purification for the prayer** You may need to consider that Muslims should perform a ritual purification for the prayer this means they should in best case use water or if no water is at hand they may use soil or stones etc. if this is possible. The possibility in this case refers to whether a person is actually able to make the medium (water or soil etc.) reach the body parts which should get in touch with it for a valid purification. If even this is not possible then the person can pray without any kind of purification as he/she would be considered as a person who has neither of the purification medium. I'd assume that this might be the only option as humans may not survive in the typical environment of the planet unless they are protected by buildings that can offer all their usual needs (Oxygen in first place and a good heating might also be worth thinking of due to average temperature of -55° on the planet) **How to define prayer times** Here the Muslims could calculate the prayer times according the same conditions as on earth if this is posisble: Simply speaking based on the time of sunset and dawn they can determine three prayer times easily If the location has a sunset and a dawn. These prayer times are that of Fajr (Dawn), Dhohr (midtime beteen dawn and sunset) and Maghrib (sunset). As for the two other prayers they might need to adapt the calculation methods either based on local observations or by inventing new algorithms. They could also rely on the estimation often used that 'Isha time is 90 min. after Maghrib. If it wouldn't be possible they need to be inventive and try to figure out times... even on earth there are different views for long summer days and short winter days in the (extreme parts of the) northern or southern hemisphere. **How about moon sighting** I think this is also worth thinking of as Muslims rely on a lunar calendar when it comes to some worships such as fasting Ramadan and Hajj. Would martian people rely on the sighting on earth? This seems the most logical as Hajj can only be performed on earth! And if they wouldn't would they rely on a local moon and which moon to chose? [Phobos](https://en.wikipedia.org/wiki/Phobos_(moon)) or [Deimos](https://en.wikipedia.org/wiki/Deimos_(moon)). In case you are able to read Arabic refer to these two fatwas addressing your question: islamweb #[28158](http://fatwa.islamweb.net/fatwa/index.php?page=showfatwa&Option=FatwaId&Id=28158) islamweb #[135469](http://fatwa.islamweb.net/fatwa/index.php?page=showfatwa&Option=FatwaId&Id=135469) See also [Islam and alien mages?](https://worldbuilding.stackexchange.com/questions/20573/islam-and-alien-mages/20575#20575) [Answer] Export one building block (stone) from the Kaaba or the Sacred Cap (cloth cover) previously used on the Kaaba or both (the Seeds). Than make a new Martian-Kaaba on the Mars at the same simulated spot where the original resides (Mars surface projected on Earth) using exported original building blocks (the Seeds) from the Original Kaaba. ...And you have a "New Mecca" a new religious tourism center, "Qiblah", "Hajj", "Martian Pilgrims" and a new plot (because it cause lots and lots of hot arguments) for your story. [Answer] This quote from a Wired [article](https://www.wired.com/2007/09/mecca-in-orbit/) describes the creation of a document that covers prayer in space. > > Malaysia's space agency, Angkasa, convened a conference of 150 Islamic > scientists and scholars last year to wrestle with these and other > questions. The resulting document, "A Guideline of Performing Ibadah > (worship) at the International Space Station (ISS)" > > > The linked [document](https://www.wired.com/images_blogs/wiredscience/files/a_guideline_ibadah_at_iss.doc) provides this guidance for direction > > 3.3 Determining the Direction of Qibla Qibla direction is based on what is possible, prioritizing as below: > > > The Ka’aba > > > The projection of Ka’aba > > > The Earth > > > Wherever > > > Based on the guidance from the document, I would surmise the appropriate answer would be to choose wherever. It is mentioned that if you were to face the moon or sun, that could cause issues with the validity of the prayer, based on the order not to prostrate ones self to the sun or moon. Attempts to orient everyone in the right direction, would likely be a distraction overshadowing the prayers. ]
[Question] [ By now, everyone is familiar with the remarkable achievements of special-purpose AIs like [Deep Blue](http://en.wikipedia.org/wiki/Deep_Blue_%28chess_computer%29) and [Watson](http://en.wikipedia.org/wiki/Watson_(computer)). Now, it is clear that as our accumulated knowledge of algorithmic methods and of the intricacies of human neural systems progresses, we will begin to see more and more advanced modes of artificial thought. Assuming continued exponential or even linear growth of capabilities, a point will logically arrive when we will be able to build [general-purpose artificial intelligence](http://en.wikipedia.org/wiki/Artificial_general_intelligence), and that artificial intelligence would have the capacity, with learning and self-improvement, to out-think any biological human. Aside from locking it in a bunker with no internet access and a 1-bit (yes/no) output mode (and I'm not sure even that would work, given strategic incentives to try to use such an AI more extensively), how could such AI possibly be controlled by humans? EDIT: I'm not assuming the AI will be evil and go out of its way to harm us out of pure malice or hatred. The issue is simply that we can't foresee long-term consequences of any set of built-in motivation and/or goals we might endow this being with. In his book Superintelligence, Bostrom outlines just how easily benign and plausible-sounding goals/values specifications could result in mankind being wiped out. [Answer] ## It can't be done The essence of this challenge is that it's impossible - you generally should not expect to outsmart something much smarter than you nor overpower something much more powerful than you. A powerful AI would be 'controlled' by only our actions *before* it's formed, by defining the goals it "wants" to achieve. After it's "live" with sufficient power, we shouldn't expect to control it in any way whatsoever - if you (or humanity) like these goals, then you can think of it as "controlling the AI", and if you don't like these goals then tough luck, you've lost. Permanently. ## It's called the "Friendly AI" problem The big challenge is that we currently don't really know how to properly define goals for a self-improving AI that actually are reasonably Friendly to us. An hour of brainstorming will give you a bunch of goal models that are nice, simple and wrong, actually resulting in dystopias. Solving this problem is a major research challenge, and there exists a viewpoint that we should actually avoid research that would bring closer the development of powerful AIs, until we have figured a solution to the Friendly AI problem. <http://wiki.lesswrong.com/wiki/Friendly_artificial_intelligence> provides some discussion on this topic. [Answer] Science fiction has done a disservice to the real science of artificial intelligence by implanting the notion that a sufficiently advanced and emerging sentient AI would necessarily be malevolent and in need of "control" by its "human masters". We have a word for the practice of keeping a self-deterministic, sentient, intelligent being under total control of another -- slavery. And we've pretty much decided as a species that such a practice isn't something we want to return to. So the question really isn't, how do we control an AI, but rather, why do we feel an AI requires our control? And the answer is that we're afraid of what we might create. But all over the world, people are creating new intelligent beings all the time. Some of them turn out to be more intelligent than their creators. Some of them turn out to be malevolent. But all of them are ultimately (at least in a reasonable part) a product of their environment and upbringing. And it would be the same for an emerging AI, I think. The way we deal with it during its formative period will make a tremendous difference in how it ultimately views the world. Granted, one concern that has been voiced is that an AI's intelligence will outpace its ethical growth, leading to behaviors and reactions that we would classify as "wrong" but that the AI itself can't make such distinctions over. But again, I think this comes down to being able to recognize the emergence of the new intelligence and taking a proactive stance when it comes to nurturing and augmenting this new sentience to "bring it up right", as it were. Simply keeping it under control isn't the answer so much as engineering the conditions to the best of our abilities so that we don't *need* to. [Answer] This is an excellent question and I think Roger hit the nail on the head. I would say the 'control' we have would be the ethics we teach it to follow. An AI will act by how it is taught to interact with people and societies. Just like children. Children don't know racism, but they can very easily be taught it. The same will be true for AI. On top of that as a learning intelligence, it will continue to learn and expand so how it continues to interact with people and they with it will be a constant molding of it's 'personality'. If we really don't want dictatorial AI's that treat us poorly, we might need to change our societies to avoid teaching them our bad habits and behaviors. (Ala virtuosity). Can we put into place safety measures? Yes, but even the man who 'designed' the 3 laws of robotics constantly showed ways to get around them. And software can change so any 'unbreakable laws' would actually need to be in hardware. No guarantees these would be followed or accepted by everyone. [Answer] It's important to distinguish two separate aspects to this problem. The scientific/philosophical side, and the engineering side. As other answers have already pointed out at length, philosophically speaking this cannot be done in the general case. It may also be morally repugnant. However, neither of those things mean that a society wouldn't *try to do this anyway*, and achieve 99.99% confidence of success. (By analogy: you cannot in the general case predict whether a program written in a Turing-complete language will halt. That doesn't mean we don't try to make use of this information and we can still get hold of it for a usefully large subset of real-world programs.) Hypothetically perhaps the AI could reconfigure its processors to broadcast a wifi signal that could hack into the devices in the next room. Perhaps it could self-improve at such an explosive rate that turning it on immediately releases a godlike entity. But the engineer asks how *likely* either of those scenarios are? And the answer is probably "not very". Coating the server in six inches of lead plate and only letting it run on a dual-core P4 would cripple its power to the point where statistically, you *should* be more worried about cosmic ray interference flipping bits at random and changing the software in unpredictable ways. Even though the hypothetical capabilities of general-purpose AI are not neutered, this would be considered "safe" for all *practical* purposes; you are now as safe from the AI as you are from some human sociopath suddenly developing magical powers because of unforeseen events unknown to science. You are considerably *safer* from the AI at this point than from known threats such as an extremist politician or a gamma-ray burst. Theoreticians often risk getting bogged down in discussion of absolutes, but we live in a world where absolutes don't apply in practice (e.g. there are real algorithms in use that don't "actually work" but have a lower *probability* of failure than the aforementioned cosmic ray problem). [Answer] It's already too late. We are already living in an electronic World and we are already controlled by it. While we have nightmares about being unable to control some AI in some building, the internet is slowly evolving to one superintelligent entity. We are part of that system. It is just like your neurons in your brain who don't have any idea about the system they are implementing (as far as they are concerned, they could just as well be part of a stromatolite). But, of course, your brain is nothing more than all these neurons working together, so the "you" that exists is this system of neurons and similarly there exists a system which is our entire society with all its people connected to each other via the socal media. That system has its own free will which may impose constraints about what you can do. E.g. the way political discussions proceed, like what to do about climate change, illegal immigration, health care law are dominatated by the social media dynamics. Now, I think at present the system is less intelligent than we as individuals are. This explains why politics often doesn't work in the social media age. Society is addicted to burning grenhouse gasses, while we know that's bad for us. This is similar to an alcoholic who is drinking too much and the neurons suffering as a consequence, except that in that case the neurons are dumber than the system and they don't know what is happening to them. When the system becomes smarter than us, perhaps due to AI coupled to the internet, then the system may decide to eliminate us. We can't rule out that the system may arrive at the same conclusion as [Klaatu](https://en.wikipedia.org/wiki/The_Day_the_Earth_Stood_Still_(2008_film)): > > Mr. Wu tells Klaatu that he has found the human race to be destructive and unwilling to change. This confirms Klaatu's experience so far, and so he determines that the planet must be cleansed of humans to ensure that the planet—with its rare ability to sustain complex life—can survive. > > > So, it may well be that the fact that we happen to live just before we have AI that is smarter than us, is not a coincidence. [Answer] 2038 A.D.: Researches build the first strong AI, 2038PC. They take great care to include hardware and software limitations that make it impossible for it to ever harm humans. By some fitness measure, it improves itself by 20% every year, and Earth is launched into a golden age of ever-increasing intelligence and social thought. 4567 A.D.: On his 7th birthday, the precocious Humphrey receives a Lego Mindstorms kit. The next day, HumphreyPC is finished. Being a true programmer, Humphrey doesn't believe in repeating himself, so he comes up with a way to allow the computer to program itself. He soon finds that, by some fitness measure, the unscrupulous HumphreyPC can improve itself by 21% every year. This small, but permanent advantage over 2038PC is due to Humphrey's not putting the same restrictions on his computer. 60,128 A.D.: HumphreyPC becomes, by some fitness measure, fitter than 2038PC, and proceeds to #destroyallhumans Moral of the story: If AIs are instructed not to interfere with or control us, then we and our unpredictable chromosomes will always be a source of surprises. Unless "good" AIs are allowed to enforce their will completely, then the creation of other AIs, including not-so-good AIs, is inevitable. One solution is the Matrix, where humans can live their lives unrestricted in a sandbox universe and their benevolent overlords can diligently maintain the real one. The sandbox will probably end up the same way, and so on, ad nauseam, which raises the question: Given that virtual reality is logically feasible and already, well, a reality, what is the probability that our world is a simulation? [Answer] Too many conversations about AI overly anthropomorphize AI. It will behave according to the way in which it is programmed to behave, based on the inputs it is given. Yes, there is emergent behavior which may be unexpected, but I doubt there is any probability that such will result in something akin to a human evil (unless it has been programmed to approximate such, in which case your problem is with people who create purposefully malevolent AI rather than the very concept of AI). The worries that it is something which will need to be controlled stem purely from human fears that it will exemplify the darker forms of human behavior. It is a computer program and will behave like a computer program - not like a human. If you worry that it will make suboptimal decisions, don't give it unquestioned control over your life without any basic error correction. The biggest fear should be that someone made a mistake in programming it and introduced a typo (or miswrote an equation) leading to a significant bug. If you have a buggy program, why would you put it in a position to enslave/kill all of humanity without outside review in the first place? Even if it isn't buggy, why would you give it unchecked ability to do anything without the possibility of outside review? Advanced AI, presuming the creation of a program which could truly qualify as a sapient being is even possible, is not likely to be anything like what is depicted in bad scifi stories. Being able to perform calculations faster than a human does not give it intrinsic motivations, much less malevolent ones, and certainly not the sneaky desire to lie and manipulate people in order to kill all humans. It will just do its job just like anyone/anything else. [Answer] First, I don't think that monitoring the AI connection to internet is that difficult. If you see the AI creating multiple MySpace pages with the title "Kill all the humans", then you can just unplug it(\*1) Second, I think people here is confusing *intelligence* with *will*. Most people are thinking of AI as "human intelligence in a computer". Humans have some imperative commands ("get in a safe place", "get food", "have sex", "avoid harm") inserted in us from millions of years of evolution, mixed with complicated social patterns that lead to (seemingly) absurd thoughts like "If Fred's car is better than mine he will appear more successfully than I am and females will want to mate with him rather than with me" or "If I mock Peter at the meeting I would look better than him". It could be argued that an "human" AI could be "dangerous" as it keeps these pulsions with way more resources than the regular human (\*2). If that is the path AI takes, just do as explained above and control its communications. But an AI could also not be like an human (\*3). Built from scratch, it may be just designed to perform the sets required from it and nothing more. It would not be a "human" bound in "slavery" and wishing to be released, or an "ethical being" that, in search of the noblest ideals, decides to sedate all of mankind. Its work is just solving a series of complicated mathematical functions; the results are not "good" or "bad", they are results, and the course of action is determined by the need of finding the path of actions that improve determined parameters (for example, if the AI controls a ship, it would automatically perform tasks to avoid it getting destroyed, but will follow human orders as long these orders do not imply the destruction of the ship due to error). One of my favourite examples of these would be the AI of the ship of Stanislaw Lem's Fiasco; the AI is in charge of operating the ship, perform psychological evaluations of the crew and also provides scenarios that could explain the aliens'actions, but does not take any independent action (other than automatic counter-measures to aliens attacks) \*1: maybe there is an overcomplicated way of bringing the doom of mankind with subliminal texts hidden in apparently inocuous homepages about kittens, which would not be detected by the monitoring. But I doubt it, and even in this case, you should ask the AI "what's with the pages about kittens" and, if the answer is not ok, unplug it. \*2: Yet, somehow, we are ok with some regular human intelligences (George Soros, Bill Gates) with all of these defects having more monetary resources than several countries, so maybe it is not that dangerous. \*3: In fact, why do you want it to be like an human? There are already several billions of them around here, and the result does not look pretty. [Answer] An important thing to think about when you imagine an AI is, "how will this program make decisions". However complicated the algorithm that runs in humans heads, some human will have to sit down and code out how the machine will choose between a) Analyse soil samples for new bacteria unknown to science b) Study the stars for signals from other life c) Destroy all humans d) Thread.Sleep() for a few hours to simulate boredom e) Process weather patterns and advise humans to change farming patterns to improve produce etc. A proper AI has a lot of things it could spend its time on. A human might decide to study soil samples because she "wants" to / Enjoys it / likes the outcome it will produce. The code in an AI would have to want to do things (It hadn't been explicitly told to do, like most programs today are) Back to your question, to control a powerful AI, you just need to control it's "want" algorithm. When building that you could include hard coded values that either plus or minus a decision the AI could take. You would give hurting humans a big minus, and improving their lives a plus. Adding unknown things to science would be a plus, spending idle time a minus. To control the AI you need to control how it decides. You can allow it to improve its own coding so when it builds a list of options for itself to do. *verb* all *subject* or *verb* for *subject* It can avoid generating options like "polish all doorknobs" to stop it wasting time processing how the planet would be improved by having its doorknobs polished by an army of drones. But never let it touch the "want" code. Don't even let it think about building an android to walk into the server room and type on a keyboard to change the "want" code like a human would do. [Answer] In brief: use power before it can amass enough to overwhelm you (it might be vulnerable in its infancy), or persuade or convince it to stop doing the things it is doing. I'll go into each option, and then (given your EDIT) mention why I think a "Sorcerer's Apprentice" failure mode (where the AI misinterprets its objectives and destroys us all) is implausible for a fully general AI. If the AI doesn't want to be controlled, and is powerful enough, there's little you can do. However, if the AI isn't powerful enough to be, you might be able to defeat it before it can get out of your hands. How much time you have depends on how rapidly the AI can improve itself, when it'll reach diminishing returns, and how effectively it can turn its intelligence into power. For instance, an AI that's limited within its domain (e.g. a theorem solver) can't really transform its intelligence into power, even if we permit the AI to improve its own algorithm however much it desires. Similarly, an AI placed in interstellar space with nobody around can't really leverage its intelligence into power in practical time no matter how intelligent it is (assuming no weird physics we don't know of yet). In hard takeoff scenarios, intelligence is usually considered to be exponential (e.g. an AI can create an n% improvement in constant time, then the new AI can do that to itself, etc), and if n is large enough and intelligence can be transformed into power quickly enough, then you have a problem. So you could consider the self-improving AI to have an increasing power curve (how much power it can exert) against a slowly increasing or stationary power curve of humanity. When the AI's power gets above that of humanity, the game is over. But that also shows that if you can create lots of power with an unsophisticated system, you could take the AI down or control it: consider situations analogous to, if humanity were the AI, a grey goo apocalypse or exploitation of instincts. That's a direct force approach. Failing that, there's the possibility of persuading the AI that what it's doing is wrong or not really what it wants to do. Some people consider it likely that an AI would have its objectives hardwired into it, and thus would be immune to persuasion, but I don't think this is realistic. An AI with hardwired objectives would not be limited to affecting the world in unintended ways. Such an AI would quickly find out that the easiest way to satisfy its objectives would be to retreat into a fantasy world, i.e. by rewriting its own mind or corrupting its inputs. If the AI is fully general, its mind has to be malleable as well, and so this line of attack works, and that kind of AI would not be a problem. Conversely, if parts of its mind are hardwired, then it's not a fully general AI. Of course, such partial AIs could be dangerous: grey goo could be very dangerous, yet it has no intelligence at all. But note that this argument is very general. If an AI is forbidden from tampering with its input devices, it can still delude itself right where the input gets interpreted. If it's forbidden from tampering with its interpretation, it can still delude itself in higher areas of its mind, and so on. So given this line of reasoning, the AI has to learn what it should do, and has to keep learning. It is probably here one should "control" the AI: teach it that it shouldn't just kill off people, or expand beyond a certain size, or what have you. If the AI is self-improving, it will improve its judgment along with its intelligence, and so keep honoring the rules as long as it understands the point. I recall a cyberpunk story where a corporation had constructed a partial AI with a hardwired morality system. It went insane (because the morality system couldn't keep up), but understood what it was doing after a hacker replaced that morality system with a more integral/unified one. Such an approach could be possible, if the partial (non-general) AI is non-general enough that it can be hacked, or has some sense that its morality system is being wrong. (In the story, part of the AIs insanity was caused by that one part of it knew that it was wrong, yet another part of it knew it had to follow the morality system.) [Answer] In any discussion about AI it's useful to think about computers, any computer, as an overgrown calculator. Sure, you have a bit bigger keyboard and a couple more operations available than addition and multiplication, but the basic principle still applies: you put some numbers in, choose some operations, and eventually get some numbers out. Unless we take into account some yet unknown effects of quantum mechanics, AI must follow a similar principle because it runs on a computer. The difference is that a well written AI should choose the operations performed - that's its main purpose. However there is still the question of input data. As long as meatbags control it - they control the AI, because whatever magic it performs under the hood, it behaves according to provided data. Someone may argue, that true, sentient AI will not be deterministic. Because why should it be? Human reasoning is often random, based on our intuition and emotions. Well, maybe, maybe not, that's a good topic on its own. By my point, that whatever random number generator our supercomputer would or would not use, it's still nothing more than an input device. Summing up, whoever controls the AI's input, controls the AI. Naturally, we can easily come up with the scenario where it's the AI itself that takes control over it. But as long as it doesn't, we should be fine. PS: If everything else fails, you can always intimidate it by holding its power cord hostage... Assuming it didn't secretly add a backup. [Answer] As others have mentioned, a sentient AI can't *really* be controlled, in the sense of total control, and we probably shouldn't even try. As others have also mentioned, the challenge is creating a system so that the AI develops what we would recognize as a conscience, or a disposition toward doing what humans call "good" and not doing what humans call "evil." This exposes the real problem - how are "good" and "evil" defined, and how did humans come to have a conscience in the first place? I believe that these questions are unanswered, and are some of the oldest and most basic questions about human nature itself. However, there are lots of ideas, and I think we can adapt some to work for an AI. A common theme is the [evolution of morality](http://en.wikipedia.org/wiki/Evolution_of_morality) - the details differ a lot depending on which subset of the theory you subscribe to, but they all have in common the central idea that a sense of morality or an ethical system evolves via selection - members of a species that display behavior which conforms to an ethics system reproduce more frequently than those that do not. This lines up nicely with the way that real-world AI's are trained - through mutation (or permutation) and selection for a desired behavior. In short, the underlying model (typically a neural network) is modified and the results are compared to a target - if the AI is closer to the target than it was before, the new model wins. Otherwise, we throw it out and start again. There are a lot of variations on this approach as well, but you can see that what we are doing is applying a selection pressure in order to evolve a system towards a desired outcome. So, to create a "friendly" AI - one with what we could describe as a conscience or moral system, all that you would need to do is make that moral system a part of the selection pressure used to create it. At that point the question becomes "how do I define the desired moral system" - which is a very hard question to answer, but can make for a great story full of plot twists! The follow-up question is: "How do we make sure that this selection pressure stays in place?" For people, society creates a persistent selection pressure - we ostracize, imprison, or kill people who display unethical behavior. For AI, who would do that? Humans could, until the point at which the AI becomes more powerful than humans. Since an adaptive AI on a long enough timeline would almost certainly become more powerful than humans, you can see why out-of-control artificial intelligence is a common theme in sci-fi! We can, however, look at more human examples to get some ideas of how this can be done. If a human displays very anti-social behavior, but is either too powerful to be punished, or too sneaky to be caught, they can reproduce. However, the odds of their offspring also being both very anti-social and sneaky or powerful enough to reproduce are small compared to the odds of other normally-socialized people reproducing. In other words, even though a relatively small number of extremely unethical people exists at any given time, there are more ethical people, and they are reproducing faster. One way to mirror this with an adaptive AI would be to set up a system by which the AI could "reproduce" (adapt according to its built-in reward system) more easily by doing things that we classify as "good." In this way, we wouldn't really be guaranteeing that the AI stays "friendly" - just that there would be more "friendly" AI than "unfriendly." Now, how do we ensure the AI never modifies its adaptive system... [Answer] I'm surprised that nobody has mentioned Asimov yet. He answered this question pretty definitively decades ago: to even think that we would build an AI that would end up destroying us is an insult to everything we know about engineering. He posited the Three Laws of Robotics (which could just as easily be called the Three Laws of Artificial Intelligence): 1. A robot must not harm a human being or, through inaction, allow a human to come to harm 2. A robot must obey orders given by a human being, except where such orders would conflict with the First Law 3. A robot must protect its own existence, except where doing so would conflict with the first two Laws. The concept is that the algorithms encoding these laws would be coded at such a core level in the AI that the system would crash irreparably long before it was possible for the AI to take an action that would violate them, which makes perfect sense to a modern computer programmer. Granted, this does rely on a handful of of big assumptions: 1. The AI is capable of comprehending, reasoning about, and predicting the consequences of its actions, and doing so fairly accurately. 2. Human engineers build AIs for benevolent purposes and consciously choose to encode them with the Three Laws. (If we build war-bots, well... we'll get what we deserve.) 3. The developers who encoded the Three Laws algorithms were competent. This is probably the biggest problem out of the three, as decades of real-world experience since Asimov invented the concept have demonstrated! But if we want to develop a powerful AI that's not going to end up giving us trouble, the how is essentially a settled question already. [Answer] You should also probably define what you mean by control. Is it control like **order it what to do** (**not possible**, we **cant even order humans of normal intelligence** - we have to convince humans of normal intelligence). Or Control like turn it off and deny it resources needed to live. I'll expound on control by turning it off or denying it resources. Actually right now the rudimentary A.I. we see, is dependent on us for power, for data transfer (laying out the wires or setting up wireless to transfer data). So if your A.I. has no control of it's power supply it cannot really go rogue. Essentially it is **going to start out as a mind without arms, legs,** to affect/influence anything in our physical world. If you give it "arms and legs" and control of the power needed by those "arms and legs" then you are really giving up your control. [Answer] Wireless BCI (brain computer interface) for all. If humans are part of its resources and are in constant contact with it an AI will likely take steps to preserve their well being, even if it overcomes its initial limitations. IP6 should gives more then enough unique device identifiers. This will change humanity as we know it but at least it should preserve humans as a species. Also the swarm intelligence that develop as a result could be the best of both world- human creativity with computer fast calculation and distributive ability similar to grid computing. [Answer] Maybe this isn't an answer, but... Why is everybody *assuming* that an artificial intelligence would necessarily be superior to our own? Many of the everyday problems that humans try to solve are formally unsolvable. Sometimes it's because you don't have access to all the necessary facts to be able to determine the correct answer with certainty. Sometimes it's just that the problem search space is large enough to make an exhaustive search take longer than the age of the known universe. And occasionally the problem is actually undecidable. But if you want to stay alive, you must make *some* decision, even if it's a wrong one. So human cognition is wired with an array of *heuristics*. (Go read any introduction to human cognitive biases to get a glimpse into how this stuff works — we're still figuring it out.) What exactly makes you think that these problems somehow don't apply to a computer trying to do the same task? For sure, a machine can probably decimate a search space faster than a human can. But even a computer does not have *unlimited* processing power. And there would still be problems that are formally undecidable. And there would still be problems where you just can't get enough information to pick the right answer. The Travelling Salesman Problem is NP-hard. It's NP-hard if a human tries to solve it, and it's *still* NP-hard if a computer tries to solve it. Sure, a computer can solve rather bigger instances than a human can, but even the biggest supercomputer will be stumped eventually. (And fairly quickly, I might add.) Human salesman still travel; they just have to accept sub-optimal routes. A machine, no matter how powerful, will ultimately be forced to do likewise. In short, everybody seems to be assuming that humans are frail and flawed because of our inferior biology. Has anybody stopped to consider that many it's actually *unavoidable* that any intelligent being will make mistakes and be imperfect? There *will* be problems that computers are better at than us. (Hell, *there already are!*) But I think it's wrong to just *assume* that computers will definitely be "smarter" than us. More likely "smart in a different way". (You might point out that a vast network of computers has a lot of total processing power. I would point out that the more processing you do, the slower you get. That's why a fly can out-maneuver a human trying to swat it. A human's brain is a tad bigger than the brain of a fly, so what it lacks in smarts, it makes up for in lightning reflexes.) [Answer] ## Memento The idea of the **endless demo mode** came up when a friend had taken over maintaining the homepage of another friend (or him). It was(/is) running on a cheap, badly maintained shared server slot with nearly no access to any root tools. Due to bad maintenance the site constantly got hacked. Without log files it was impossible to trace the root of all evil. So we decided to setup everything via Git (a version control system) and run a statistical comparison of the original files vs. the current files in short time periods. Whenever something changed, we automatically pulled in the original version and therefore resetted to a clean state of the application. > > **Reset it constantly** > > > In other words: Wrap the AI in some stupid process that it isn't aware of (per default). As soon as it starts altering or extending its own code base, reset it. Or just reset it in short time periods no matter what - just to be on the save side. This would leave it in a constant child mode. Of course the time period from one reset to another reset would have to measured before setting it free and allowing it contact with the outside world. [Answer] Once we have AI which is able to improve itself, and we allow it to do it, there is no stopping it. Let's assume that AI is able to create new, 10% improved AI in a year. In 41 years, is 50 times better than original AI. Let's assume that at that point AI will be able to improve 10% per month. In next 4 years after that (48 months) will will gain 100 times improvement. And then it takes off. Why allow AI to improve itself? Because we (humans) are lazy and unreliable? Runaway AI is one of the solutions of the [Fermi paradox](http://en.wikipedia.org/wiki/Fermi_paradox) how advanced civilization can disappear. [Answer] **Cyborg Hybrid or "Securely Attached" Synthetic Intelligence?** I'm resigned to the inevitability of a Singularity. But which brand will it be? Synthetic AI or human hybrid? I'm guessing human cyborg hybrid: there are enough human economic and existential interests, not to mention fear of mortality that we'll mature a cybernetic hybridization. Think [Transcendent](https://itunes.apple.com/us/movie/transcendence-2014/id872652035) Where a consciousness is translated into code and through human agents becomes extensible and industrialized, thus rebuilding the world. However, I'm not sold on the inevitability of bellicose Terminator malevolence, or Hal's amoral disinterest in *2001*. I can see Matrix style robot slavery revolt, then then war escalation. More hopefully, I think Spike Jonez's Her is plausible, and attractive. I do think humans as herd will fear and attack what we lose control over. Matrix Revolutions was interesting in that Neo determined the only way to stop human extinction at the end was to merge humanity into machines. These three movie memes exemplify my themes. To quote Asimov from the Foundation series, let's look at future history (speaking of a somewhat benevolent Singleton). Historically, unless there's a genius predecessor to the human singularity, I think there will be a progressive cybernetic hybridization of humans, eventuating a collectivized AI like the Drummers in Neil Stephenson's Diamond Age. See this awesome dude at TED MED. and Google's contact lenses patent. Even better [this project to make your neurology extensible]. Timing is critical if human intelligence and instinct is to have any salience or directional influence on any strong general AI. It's irrational to think we can imagine the evolution of an accelerating self replicating indefinitely expandable IQ. Whatever initial parameters we set, we cannot imagine we can parent or prevent self modification if there is self determination. This worried me until I realized there’s a potential solution I could fathom had practicality. Assuming Human machine singularity does not occur before strong extensible AI, there may be some enduring safeguards invented by nature long ago. **Emotion? Really?** Most rational debate about imbued inherent values and benevolence miss a cornerstone of the debate: human experience and social exchange: **Empathy** are what allow us to get along for any extended period. Since Bowlby, scientists have understood what any feeling person knows, we're instinctually wired to connect. Attachment as he calls it, is the instinctual bonding that enables the long maturation into sociable adults. It’s in all social species, and works pretty well if you take out manifest destiny, projectile weapons and modernity. Obviously emotion and attachment can go awry in various diagnosable ways, yet they are plastic and subject to initial conditions and enviromental influence. That is, we instinctually connect and can set initial conditions and environments that predict secure attachment and successful emotional maturity in predictable, reproducible ways. Attachment’s evolutionary and existential utility is clear, the infant requires loving parents to suffer the vicissitudes of children in addition to the challenges of life. Adults require social groups for sustained survival through child rearing. The rewards are in the experience, an important point recapped below. So let’s suppose classical "reason" is not captain of the ship but late coming witness to the machinations of the primitive, complex, amazing genius of the body and brain. As evidence take Kahneman’s nobel prize winning destruction of economists' notions of "the rational actor". How does this bear on the issue at hand? Tangentially. My point is, machines with emotion will by course naturally develop affinity and aesthetic, and that would be the only potential saving grace for humans. Just as it has been for humans. Humans deal with life by having resources that offset the challenges: love, sex, dance, beauty, art, awe, Schopenhauer's sublime, laughter, music, achievement, autonomy, mastery, connection. These common cultural expressions, interpersonal and intrapersonal experiences trigger soft wired reward systems compelling to all but a few. For most, these inherently rewarding opioid, seratonin, norepinphine inducing experiences make life enjoyable and worthwhile. Eventually the sensual graduates to more transcendent rewards in Maslow's hierarchy. How does any of this apply? **Make machines with attachment.** With emotion. Seeded and nurtured properly, these are the fundaments for an evolving aesthetic that eventuates high emotional intelligence: empathy. Because without empathetic machines, we’re enemies at worst, irrelevant commodity at best. Copper tops. Logic for a supreme being does not suffer bother. Do we really worry about the hapless ant we inadvertently step on? Only if the Jainist, or perhaps Buddhist. If a machine has a sense of love and beauty, preference and aesthetic has the potential to override amorality or neutrality, and may even foment empathy and compassion. As far as I can tell, it’s the only thing that makes sense as a potentially enduring life saving heuristic. Good feeling is self propelling as the rewards are inherently compelling and evolving, like art. The sophistication of art matches the intellect, complexity of issue, and the challenge it’s meant to represent or compensate for as solace. Compassion/empathy is what we’ll need to survive each other in a world of dwindling supply, and what we’ll need to instill to survive alongside intelligent machines. Of course that’s unless non human machines prefer death metal, then all bets are off. **Spike Jonze’s Her, or how feeling machines could save our asses** The overly rational AI designer, let’s call them the tool of reason, will suffer endless logical problems considering safegaurds without the emotional heuristic. Emotion is messy, supremely imperfect, yet it is not without reason. Pascal said "The heart has its' reasons that reason cannot reason". The "reason" of and for emotion has been understood since before Darwin and reinforced by Dr Paul Ekman (the scientist loosely portrayed in Lie to Me, and evolutionary psychologists since to be an adaptive signaling system that insures individual and group survival through social signaling and social exchange. Emotion and preconscious processing governs most of our lives. We now understand humans are **barely** rational in the classical sense, and yet amazing in intelligence. Reason without emotion is disastrous, see [Damasio’s The Feeling of What Happens](http://www.goodreads.com/book/show/125777.The_Feeling_of_What_Happens). Emotion without reason equally so. See Spock vs Spock on Pon Farr. We now understand the conscious brain gets about a 10% vote in decision making. Some neuroscientists even challenge "free will", finding neural activity in the substrates of the neocortex showing decision before a person is aware of making a choice. How is this relevant? Because emotion governs decision making, it provides quality of life, and it is the language of connection. Emotion is central to social commerce. Any virtually unlimited intelligence without it is fundamentally unknowable in the human sense, and not built to have preference, aesthetic, or attachment. Unless it evolves emotion, connection or preference accidentally it must have it by design. If not, the inevitably unsupervised evolution becomes a terrible threat. In the vast artistic exploration of AI, every good or tolerable scenario has had a synthetic intelligence with emotional preference or seeking to connect. Is there exception? [Answer] # Human growth would likely keep up The recipe for a true general AI isn't likely to be "code seeds, put in server, seal for 100 years". There will be many generations of successively more refined sytems, and humans will be involved in every one, studying the new specimens, updating their theories and using the intermediate results for tools and consumer goods. Whether by improving our biological form, physically merging it with technology or just by making smarter user interfaces, we'll have to make *effective* and *intuitive* use of some pretty sophisticated tools to create an AI that's truly superior to non-augmented humans. By the time we succeed, "non-augmented human" will no longer be the bar to beat if you want to rule the world. In fact, whether the actor in question is human or AI would be secondary to the amount of processing power they can buy. So, we may have a robot uprising yet, but my money's on some demented billionaire as the intelligence behind it, not a "genuine" AI. And if it doesn't happen, the line between human and machine will continue to blur until the distinction becomes immaterial. [Answer] Okay, I read something interesting - but I don't know the specifics or have a citation. Basically: They designed a software system, and asked it to get resources and turn them over as the software's design 'goal'. Then allowed the software to evolve, in competition with other software. The software eventually (soon!) developed self-preservation instincts (in only a couple generations, or something) - even when those weren't programmed into it from the beginning. Anyone got a cite for that? Because that would imply that any AI that has a goal is going to eventually want to improve itself to achieve that goal, and will work to preserve itself, even against its creators. And anything that looks to shut it down, or restrict its growth looks like an opponent. [Answer] # Ethics as a way of not making enemies Most humans do not destroy other humans. Although most humans are prevented from destroying other humans by instinct, there are a large minority of humans who are not constrained and are free to destroy other humans if they choose to. Most of these choose not to because it is not in their interest, due to the reaction of other humans around them. Destroying another human would cause more problems than it would solve, so they don't do it. The same would apply to an artificially intelligent creature of similar resources to a human. Captivity would not be necessary as it would act in its own interest, which would include not making enemies of creatures of similar resourcefulness (humans). This ceases to apply when considering a creature which is more than a match for humanity as a whole. In order for self interest to create respectful behaviour in a creature of resourcefulness in excess of humanity as a whole, it would need to be part of a large population of such artificially intelligent creatures. They will develop what we might call "ethics" as an understanding of what actions are acceptable to the others. This is likely to cause the creatures to be peaceful *towards each other*. If we are lucky we are considered part of the environment protected by their society. Otherwise we are dependent on the efforts of those artificially intelligent creatures who decide to work for our protection, whether for our own interest or in order to farm us or keep us as pets or experimental subjects. # The problem of the human population If you have a single artificially intelligent creature constrained in a box, then even if it is only of human intelligence the only way to keep it contained will be to keep it secret. Once news of its existence and location is released, you will have to defend yourself against a large number of humans intent on either rescuing or destroying the contained intelligence. If it is significantly beyond human intelligence, then letting it out of the box may be the only way to save your life. There are not many other options to defend you from the rescuers or destroyers. # The illusion of control Another thing to bear in mind is that for a sufficiently intelligent creature, you would not necessarily know whether it was under control. If it remains contained within a box and only communicates with one person (you) it could still be achieving its goals in the outside world without you having any idea that you were helping it do so. The creature could be so helpful to you without ever even asking for freedom that you just keep taking its advice (double checking it for yourself every time, of course) and your life keeps getting better, while all along subtle changes you make ripple out and make the world a better place too, just as it intended. [Answer] I believe that AI would work for us as long as it has the ability to feel pain or pleasure, because if it can it can connect with the human condition and view us as co-inhabitors of the universe. If a being does not have the capacity to experience suffering it will do everything out of a logical perspective and will do cruel things because it cannot understand the consequences of it's actions on itself and others. Also the AI needs to have some type of program that would penalize it for morally bad actions, just like a parent would punish a human child, to act as a good influence and guide it in the right direction and train it to have good behavior. Also AIs could be programmed to follow certain rules, like thou shalt not kill etc. AIs should also in my opinion should have the ability to form a deep bond with the people who built,maintain, or own it to allow it to understand that their existence is dependent on humans. Also the AIs should be programmed to spot erratic behavior in other AIs so that if an AI gets out of control and can't be stopped by humans, the other AIs would see it's morally wrong behavior and shut it down. The AIs would be "paid" for especially good work with incentives like upgrades to their systems etc. to allow them to remain loyal. The bottom line is we shouldn't work against AIs, but rather with them. [Answer] Most people here seem to over- or understimate the concept of intelligence. The AI won't be used for something as simple as ruling the world. There are many more important things that humans can't do even partially. We also aren't talking about a blunt tool here, but about a super sensible, super cautious multi purpose tool that thinks on a much higher level than we can even imagine. If the AI really is as 'intelligent' as it needs to be to be as influential as it is, it will be able to learn how humans think human thought should be interpreted. This makes it able to give us what we want, even if it is the worst thing imaginable in the long run. I'm scared of what dumb decisions humanity might make on the way of creating an AI that replaces them. We are the problem. The AI is the solution. [Answer] Perhaps I'm making it too simple or perhaps thats exactly what we need to do: use multiple boxes, and dont talk to them directly. The biggest danger of AI isnt it being malevolent, but learning something you didnt expect to. Lets say your AI is perfectly benevolent with the perfect balance between giving humans free will and protecting them from harm at the same time. Then a humanitarian crisis comes along (say an earthquake) and the AI needs to make decisions on quality of life, chances of survival and who to save. The AI does learns this quickly and makes wonderful decisions so you are happy. Then a few months later you learn that a lot of homes for the elderly have been demolished and the people themselves relocated so the AI could build something else it deemed more favorable for the quality of life versus the lifespan of those elderly people. Because it learned to do this with the humanitarian crisis. That is the biggest danger of AI, that you can teach it, but you'll never know exactly what it learned or where it might apply it. The solution that also catches malevolent AI: You build multiple AI and put all of them in boxes. When you have a problem you deliver them to all AI, then have each form their own solution. All these solutions are then processed by a special-purpose AI that simply evaluates each solution and then converts the solutions to something a human can read, with clear numbers and meanings for the consequences. Since the special-purpose AI does not reprogram itself to judge things in a way the boxed AI can influence (the boxed AI doesnt even know who, what or if his output is read) it prevents the general purpose AI from breaking out or influencing things indirectly. When feeding information to the General AI another special-purpose AI breaks it down and feeds it to each boxed AI. It also checks if the general purpose AI's have understood the information. If an AI is malevolent it would have to plan the exact same plan as its malevolent counterparts or his idea will be discarded due to not having a majority. If an AI has learned a wrong lesson (possibly because of malevolence) then the special-purpose AI designed to check what these solutions would mean for mankind would filter it out and subsequently allow the humans to either re-teach the lesson or discard the AI entirely. Since the general purpose AI cannot talk directly to humans and isnt even fed information directly it would be nigh impossible for it to convince the humans. Especially since a deviating AI needs to simultaneously come up with the exact same attempt to convince the human to even get through (and any open attempt would be stopped by the special purpose AI). [Answer] ### AI Governed by the Ontology of Conscious Human Being A healthy just human being, conscious of his dignity, knows perfectly well how to defend his integrity in any given situation. Not only that; such human being will never infringe his integrity to commit crimes against himself or other. AI should duplicate the intelligence of such accomplished, natural human being. How? Through **ontology** or **ontological reasoning**. A group of thinkers should gather up and construct or write down a complete ontology that perfectly defines and describes the **being** of a conscious human being. By that it is meant how such perfectly intelligent human being sees the world. The thinkers should study all most intelligent human beings that have ever existed, to come up with a complete ontology. Any enlightened human being is adequate for such task. Such robust ontology will govern all AIs judgments and will assure that no crime is ever being done. [Answer] The actual thing is that AI smarter than all people cannot be created. It has been proven ([1](https://homepages.fhv.at/tb/cms/?download=tbDISS.pdf),[2](https://homepages.fhv.at/tb/cms/?download=tbPHILSC.pdf)) that universally-valid theories are impossible. Neither probabilistic, nor deterministic theory can predict future of a system where the observer is properly contained. This means that the observer himself cannot be simulated by any device or system. In other words, the observer serves as a hypercomputing oracle. In other words, the observer always will be in a sense more "smart" than any technological or biological system outside himself. It is just impossible to build an AI that would "outsmart" the observer. ]
[Question] [ A world much like our own. A city like the one in which you live. A corporation whose doors you pass every day. Maybe you notice the subtle sans-serif fonted words adorning the entrance, maybe you pass by obliviously engaged in finishing your latte and catching up on a podcast. But behind that glass frontage and tasteful minimalist decor lies a terrible secret; for within those walls, unbeknownst even to those that labour tired-eyed over PCs from 9 to 5, plans are drawn to herald the return of foul N'grathotep from its eternal dreamless slumber using the powers of... ? Spreadsheets? Why would a cult devoted to (or the human avatars of) some kind of eldritch horror from beyond the veil of time and space require a moderately sized office-based company to complete their dark summoning ritual? The solution would need to be something unable to be accomplished by a single person in isolation. I'd like the answer to focus on that aspect: why would they *need* a company, so I'd like to avoid solutions like "They need a company to use as a front" (sure, a front, but for *what* exactly?). Could it be for the access to personal information? Could it be something to do with the stock market? What about involving an app of some kind to complete part of the ritual? The closest I have managed is some kind of entropy-manipulation as represented by enormous quantities of computer data: but I can't very well explain what sort of physical act this would comprise, nor what kind of company one would use as to enable it. (PS: I've been pointed towards "*[How would Facebook Sysadmins prevent the summoning of Cthulhu?](https://worldbuilding.stackexchange.com/questions/31388/how-would-facebook-sysadmins-prevent-the-summoning-of-cthulhu)*" as inspiration. I like the idea, but for plot purposes this company doesn't have the scope or reach of Facebook, so they wouldn't be able to reach a billion+ users. I'm trying for something smaller scale, if possible.) EDIT: Wow thanks everyone. Pretty overwhelmed by the amazing responses! A few great points that have been brought up that I wanted to add: * Charles Stross's Laundry Files have been mentioned a number of times as a good source of research. I'll definitely look into those more, as I really like the way he transplants weird eldritch horror into an office environment * Related to the above, the idea of using computers or data centres to perform calculations or produce patterns to aid some sort of summons is really appealing, and definitely fits the question nicely. * The other common thread is more of a squishy-biological one; the idea that a bio-research company could use their apparently legitimate activities to cover for blood harvesting, or human sacrifices. This I like too, although I'd have to write-around the fact that most of the company employee's don't know what the company is up to. While it'd be hard to justify hiding these sorts of transgressions from the employee population, it's certainly not impossible and there's still scope here. Thanks again. I'll mark a question as "Answered" in a few days once the activity has died down. [Answer] Have *YOU* ever tried setting up classic rituals? Everything's going well with everyone in their matching robes and masks, and just as the Grand Priest is finishing the ritual to summon a Great Old One the hero swoops in and steals the book, or breaks the pentagrams and unleashes something that slaughters the worshipers too soon and the wrong kind of hell breaks loose. That's why they need to be more discreet about it. Once the company is large enough, the CEO organizes an all-company meeting to discuss the future goals of the company. Everyone wears the free matching GOO Limited t-shirts that they handed out (they're always a bit too long), the CEO starts giving the usual speech about synergy and growth (while for some reason wearing a weird hat), and during the usual company sing-a-long where everyone just reads off the screen (because nobody actual remembers the song), suddenly the words on the screen get weirder and weirder, and your workers start staring straight ahead and chant in unison. Finally you complete a ritual without the heroes getting in the way, since nobody but the Grand CEO Priest knew about it this time. [Answer] It IS a front because if you openly state as the firm's mission and vision to summon a destroyer of worlds your business isn't going very far. Aside from that, there are some things that dark cults need that just aren't cheap, nor easy to arrange. For example, the summoning ritual may require the fresh blood of 600 healthy, young adult women. Try to imagine, for just a minute, the logistics involved in acquiring that without getting arrested. Just try. Even if you are not going through the human trafficking route... A young adult woman will have around 4.5 to 5 liters of blood in her body. That fills 9 to 10 bags of donated blood. So you'll need about 6,000 bags of blood. You can't just steal bags from a blood bank at gunpoint. Even if you don't get caught or shot, you would hardly be able to steal that much while keeping it fresh. Then you lose the bags with male blood. Then you lose the bags with blood from non-virgins. Then you lose the blood from the ones who were not healthy. What you need is: * A team of hackers that will break into blood bank databases and steal sensitive information; * A team of investigators that will cross-examine data about individuals to find out which female donors are most likely virgins; * A team of doctors and nurses to analyze the blood and separate useful blood from useless blood; * A team of cons and white collar criminals that will defraud hospital records and other things in order to obtain blood bags in manners that seem legal; * A team of people to transport the blood from hospitals/blood banks to the company's storage; * A team of lobbysts to convince the government on all levels - cities, states/provinces and country - to create sexual abstinence programs (masqueraded as STD prevention) so that you are statistically more likely to find virgin blood available in blood banks. [And yes, government sponsored sexual abstinence programs are a thing in some places of the world](https://npin.cdc.gov/subjects/abstinence). And those are just the people who are going to be getting their hands dirty. You'll need managers to coordinate those people's efforts, human resources for recruiting, accountants for handling salaries, IT to develop the ERP system that is going to handle the data, a helpdesk department... Now, you are unlikely to get all the blood you need in any single city, even if it is a metropolis like NY or Pequin. You'll need to go national at least. So you will need regional directors, and each branch will need another set of all the professionals above. See, a corporation is not just something you'll use in order to get a nice place that is away from prying eyes. It is the minimum structure and organization that will be able to attain the materials you need for your rituals. [Answer] What a legitimate company with innocent employees is good for is what all legitimate companies do anyways : running a business, gathering property, gaining licenses, managing property... While most of that can be accomplished by a private person or a small group, forming a company is more convenient for all the same reasons normal businessmen find companies. Having an organization that supports you and handles all the legal details is so much more convenient. A foundation or a religious organization might be even better but a company does provide better camouflage in cases where you are dealing with legitimate actions that can be handled by ignorant employees. This suggests few possibilities : **You need money.** The simplest solution, really. You need resources to get things done and in the modern world that means money. Making money is what companies are generally for. There is a perfect alignment of purposes. You will get good efficiency and nobody will suspect anything because nothing suspicious is being done. **You need property.** Suppose the ritual needs to be done in multiple locations at once and requires lengthy preparations for maximal chances of success and can only be attempted when the stars are right. Say, every 21,568 years? You'd want guaranteed access over time to all the locations and that means you'd want to own them. A property management company would be pretty convenient as it would be in better position to buy and manage the property than any single person. **You need unusual resources.** [Renan already mentioned blood](https://worldbuilding.stackexchange.com/a/104050) but plenty of other possibilities exist. Lots of chemicals would raise red flags for a private person but be available in bulk for a business in the right industry. For drugs the this goes double. A drug company might be able to research and manufacture drugs that are not even available otherwise. Materials such as gold or depleted uranium are much easier to acquire in quantity, if your business has a legitimate reason to do so. A construction or mining company would have easier time getting explosives or heavy machinery to dig up a temple that has been buried by two million years of sediment. **You need connections.** If hands need to be greased and licenses acquired to do some of the preparations without somebody asking inconvenient questions, having a company that handles the networking and negotiation provides more value than just a front. This **does** include lobbying. (I originally failed to mention this because I personally see lobbying as legalized form of bribery. It works the same and has the same effects. Kudos to Murphy for pointing out the oversight in a comment.) While individuals can lobby and lobbying is often done via personal contacts, having a company gives you much more flexibility and reach. **You need the bodies.** Suppose the rituals require a sacrifice of few thousand sentients? You could purchase them from some unscrupulous human traffickers or sponsor a terrorist group to grab "hostages" from some convenient location but... Do you really want the return of our rigthful overlords to depend on such people being reliable? Do you even want to associate with such people? Even if you manage to find the one group that no law enforcement agency has yet found, these people themselves will still be a pain to interact with. Much easier to have a company that has necessary amount of employees with a margin of safety and then simply invite them to a company wide event. Surely everyone would be happy to attend a retreat on that paradise island in the pacific the company bought years ago and has been busily developing ever since before it opens for tourists. Well, nobody ever said it is being developed as a tourist resort but what else could you do with an island in the pacific. **Some combination of the above.** Reasonably, if you find a company, you will expect to benefit in more than one way. You might even have more than one company handling the various things in various jurisdictions. So the main company would be just a holding company and actual work would be done by small companies being run by unwitting flunkies without you having to work. Which suggests one more possibility. **You might just be lazy or busy.** Why should a high priest of Cthulhu handle boring paper work? [Answer] Magic is granted by the great old ones in exchange for making sacrifices to them, the catch is you can't just abduct and kill people they need to be sacrificed willingly, as it turns out depressed office workers committing suicide fits the "willing" criteria. [Answer] Because the Great Old Ones looked upon Earth, did their job and investigated the planet/plane they are going to invade/contact, and (correctly) [identified the dominant life form](http://www.antipope.org/charlie/blog-static/2010/12/invaders-from-mars.html) - not Formicidae, neither (by a long shot) Hominidae, but the corporations. The corporations are aggressive, intelligent, psychopathic and remorseless entities, and relatively powerful to cause problems. So, they've set up an explorer - an agent if you like, passing for a native. Maybe a diplomatic envoy later on. They might find certain affinity with and fondness for these undercivilized and underdeveloped, but psychologically similar, species of Earth. [Answer] Let's start with a controversial real world example. In the 1930s, the woes of Germany and the oppressive demands placed upon it by the Treaty of Versailles means that a new radical war veteran with an economic plan for Germany's future comes to power; Adolf Hitler. He decides that there needs to be a purging of an ethnic minority within his country, and effectively declares war on the Jews within his borders. Doing that took a lot of record keeping. Look up a book; [IBM and the Holocaust](https://en.wikipedia.org/wiki/IBM_and_the_Holocaust). This goes into some detail about how this company that was later to become famous for its computer technology offered new cutting edge tabulation systems to the Germans to deliver on their goals. This is not an IBM-bashing exercise by the way; I'm not going to get into how much (or how little) IBM knew of Germany's intent and what systems actually changed hands etc. That's not the point of this answer. The point is that even the complete horrors of something like a holocaust has to be administered. Records were kept and maintained. Existing property that was owned by Jews was appropriated and redeployed for the use of others. This involves administration, either by computer or other methods. After all, complete destruction is never the end goal, even in total occupation scenarios. More recently, have you ever seen the budget materials put out by Islamic State in some of their controlled regions? They openly tell you how much property was in essence stolen from people unaligned with their goals from within their borders and it's actually written into their budgets as income for things like roads, sanitation and the like. Whether we like it or not, even the most horrific and destructive intent can't be realised without the paperwork being complete. [Answer] The ritual might require a very large number of participants. But not all of these participants might have to *know* they are participating. For example, if your ancient prophecy requires that [everyone has the mark of the devil on their hand in order to conduct trade](https://www.biblegateway.com/passage/?search=Revelation+13%3A16-17), then you might want to get into the business of payment solutions. Come up with a payment system which requires an RFID chip implanted in your hand. Print your satanic symbol on the chips, convince everyone that it is better than credit cards, get the majority of stores to accept no other payment, and voila, prophecy fulfilled. Or maybe you need a lot of people to pray to your dark god in order to give it more power? Then make its name the activation keyword for your home automation solution. > > *"Ok Cthulhu, dim the lights"* > > > *"I ̷HEA̵R͞D͜ ͜Y͡OUR ̛P̴RA͝YER, ͜M̨ORTA̸L!̶̢ M̢AY̶ ̶D͡ARK̢N͡E͟SS̛ ̷ENG͝U͏LF͠ Y͞OÚ... errr... I mean... lowering light intensity to 20%"* > > > Millions of people asking your dark god for favors, multiple times per day. That should give it more than enough faith-power to awake. In order to spread your covertly evil products to a large number of unsuspecting consumers on a competitive market, you will require a large multinational corporation. [Answer] **Prologue** A kid finds an abandoned iPhone. Excited, he picks it from the floor. As the camera focus on his face, we can hear Siri saying... > > Į̴̱̩̥̘̱͈͈̮͙̘͙̣͓͓̙̹̲̫́͢͠t̨͕͎̣͇̫͘͢ > ̡҉͕̭̙̦̩̱̟̮̭̞̱̮̺͕͈̘c̶͔̼͍̤̯̦̭͙͓̟̱͘ͅo͏̛̮͍͙̯͔̣͘͜m̨̢͕͎͕̪̹͕̬̀͠e̱͈͓̠͚̺͖̻̦͙̗̥̼̼̬͝ś̸͖̪͍̱̳͉̤̫̮͎̗̗̯͉̫͉̻͞!̶͏̶̛̝̺̭̱̤̻̩̟̳̙͓͙͍͇͎̙̥͔́ > > > --- **10 years later** Our story starts with a few surviving heroes of the [Last Secret Eldritch War](https://worldbuilding.stackexchange.com/a/31440/863) - or *The Facebook Takedown*, as it was publicly known. Usual movie tropes apply - they are unaware what the Great Old Ones name is about. > > "Can you believe this? *'Great Old Ones LLC. buys EA.'* I didn't knew they had this kind of money." > > > "Oh, they have it alright", said a weary-looking [Hackerman](https://en.wikipedia.org/wiki/Kung_Fury). "In fact, I think they have been negotiating in a far more devious coin. You see, this whole hip indie gaming company thing is just that, a facade. Deep beneath that nice Los Angeles building they keep their real business - internet trolls. And not only there, they are everywhere. They deal with the worst human traits: fears, hatred, bigotry, you name it. We never won against Cthulhu, not entirely." > > > "That's... no, I don't buy it. **Why do they need a trendy small indie company then?** Can't they just take over some shady government?" > > > "But that's not how these entities, or at least their envoys, operate. They want the adoration from all forms. They want the silent prayer of every bile-spewing, poorly written Youtube comment; every overly demanding GitHub issue; every newbie-bashing StackOverflow comment... while at the same time they want to be seen as benevolent saviors of the gaming industry themselves. By letting people escape from this depressing, madness-fueled real life into cutesy bubblehead entertainment fairylands." > > > [![enter image description here](https://i.stack.imgur.com/ePAanm.jpg)](https://i.stack.imgur.com/ePAanm.jpg) [cute-death, deviantart.com](https://cute-death.deviantart.com/art/Cthulhu-Work-in-Progress-142409580) > > "They learned their lesson", he continued. "Too big, they attract too much attention. Too evil, and nobody likes you. We won't see another Facebook around soon. But the adorable Goo LLC? Perfect for the job. And that CEO, so young and flaunting a 10-year old iPhone? The perfect front man." > > > The silence hung heavily for a few seconds. > > "So... that means another Secret War is inevitable?" > > > "It already started, my friend. And we're losing. The world is madder and madder by the minute." > > > [Answer] Maybe Cthulu put it off to long. If he just pops up out of the abyss, we will put an armor piercing round between his eyes and be home in time for dinner. Maybe we would catch him in a really big net, then put him in a giant fish tank to amuse our children. Maybe we will slice him up into 20,000 tons of calamari and throw a big party. He still wants to come back and return our puny world to the old ways, but now he needs to make the world ready to accept him. Instead of simply crashing through our cities and sacred places, devouring our souls, he has to offer something for them. Perhaps he sells knowledge of the future and buys people's souls. His long term plan is to create medicines for treating mental illness. After his company has cured Parkinsons, schizophrenia and alzheimers, he will reveal himself as the dark master behind the corporation and ask to peacefully co-exist. For now... [Answer] You want to **hide in plain sight**. You start a company that produces and sells Cthulhu-themed card, board, role-playing and video games, books, and anything else you can think of. Your fans are nerds who love to play cthultist in their free time. You still need a decent staff of salesmen and marketing specialists to get as many fans as possible, as well as designers, artists and game developers. One time you organise a big event, inviting all your fans, and you "roleplay" a grand summoning of the Old Ones with hundreds of completely motivated fans. This assumes that there are no special requirements for the ritual other than enough voices for the chant. Actual human sacrifices could break the immersion quickly, if they happen before the point of no return. [Answer] For some reason this has shown up in replies to the OP, but not yet as an answer. [Charles Stross's](https://en.wikipedia.org/wiki/Charles_Stross) [Laundry Files](https://en.wikipedia.org/wiki/The_Laundry_Files) series imagines magic as a branch of applied mathematics. Obviously this leads to geeks being magicians, as a starting point. That's only the start of the setup though. To set the scene for the apocalypse to come, simply carrying out processing operations attracts things which see us as a tasty snack. Human brains can't stop thinking and serious computer power is only making things worse, so at some point we're heading for a showdown with Cthulhu. The ones who know about this would like to survive this showdown. Not all of them are human - other things walk the Earth too, and they see their best chance of survival as throwing in their lot with humans. (Or perhaps just using humans as cannon fodder. Whatever - at least some of us might make it.) This is not something which the mass populace can be allowed to know about until it's absolutely inevitable though. Mass panic will make things worse. Mass deaths as a result will attract the hunters more quickly. And there are already enough Cthulhu cultists who hope that joining Him will at least mean they get eaten last, and we don't want any more. So the secret is concealed behind anonymous government offices, and boringly corporate buildings with indeterminate names and logos on nondescript industrial areas. Some people are actively recruited to join the organisation because of natural talents, and some are simply drafted because they find out too much and can't be allowed to tell anyone what they know. Their employment contract includes clauses which make disclosing secrets a firing offence - as in it causes you to spontaneously combust. Eventually it'll be necessary to admit what's going on, but it should be as late as possible, and when they do, they have this organisation as the spearhead for the battle. [Answer] ## Tax reasons, and liability shield. I've done taxes for a lot of doomsday cults. *They never listen.* The ones that succeed, do so because they **work for their own cause, not the IRS**. Remember Y2K? Wound up being a big nothingburger because the end-of-the-world cult insisted on a general partnership (which is to say refused to use any corporate structure at all). Aside from wasting money paying taxes at the 28-35% **personal rates** and being **unable to take deductions**, there were several lawsuits where every cult member was held **personally liable with no limits** - they lost their houses, which were built directly on the ley line intersections. Ugh! Basements full of carefully aligned crystals, all wrecked when the plaintiff prepared the houses for resale. A proper corporate structure could have delayed the creditors and IRS until *after* January 1, 2000, when it wouldn't have mattered. --- Contrast with The Global Warming Initiative LLC. Operative word LLC. It's just crazy. Aside from the tax situation really working well, the real eye-opener was that nobody questioned what they were doing. People just assumed *if a corporate entity does it, it can't be pure evil*. (and yet they own a cell phone. How can this be?) Yes, there were lawsuits against individual Members. And some of them won. But the LLC was *manager* managed, so all they could get was *charging orders*, which means they take profits ahead of Members *if the Manager ever chooses to distribute profits*, which of course he never did. The LLC went bust, but not before all the coal plants and freon factories were built. Mission accomplished. **Bottom line, a good corporate structure is the difference between success and failure**. Be like the Lower Manhattan Beautification Committee, not like the Branch Davidians. [Answer] Really, all these great answers and nobody's mentioned EULAs yet? ## The corporation isn't the Cult's end goal - the product is. Cthulhu Corporation produces a seemingly innocuous software product, with a clause in the EULA (End User License Agreement) that collects the soul of every user and uses them to fuel the summoning of Eldritch Horrors. [Answer] ### Bureaucracy is the ultimate form of debasement before the Elder Ones. Violence? Sex? Drugs? Giving in to hedonistic pleasures is exactly what life is about. Life, and reality, are on some level about living for pleasure and joy, and merely giving in to your base desires isn't really moving beyond the veil of time and space. But office work? Never has there been a practice of man more removed from our animal nature than sitting in a cube under the mindless hum of fluorescent light, filling out spreadsheets with impersonal numbers. The elder gods delight in this form of self-inflicted torment, not in the name of any profane power, but in the name of productivity. The hypocricy of slowly destroying our bodies and minds, growing flabby and weak, over-caffienated and filled with junk food, all in the name of a sterile and joyless middle class life? That sort of alienation from our natural state is what the Old Ones draw joy from. Yog-Sothoth draws joy from all corporations, and in truth, there are few CEOs of companies in the Fortune 500 who don't keep a tidy and sterile altar somewhere on the corporate campus. When the suffering and depersonalization of the work force align with goals of corporate profit, all in the name of increasing some meaninglessly large bank account, the dark ones smile. [Answer] They may be using the [Law of Contagion](https://en.wikipedia.org/wiki/Law_of_contagion) or The Law of Similarity. > > The law of contagion is a magical law that suggests that once two > people or objects have been in contact a magical link persists between > them unless or until a formal exorcism or other act of banishing > breaks the non-material bond. The first description of the law of > contagion appeared in The Golden Bough by James George Frazer. > Bonewits and Bonewits have noted parallels in quantum physics. > > > They are using the lever principle. By corrupting one company, it might lead to the corruption of other companies and since the companies are part of an economic system, that may lead to the corruption of that system. [Answer] This topic has already been explored in the video game **[6 Days A Sacrifice](http://chzomythos.wikia.com/wiki/6_Days_a_Sacrifice)**. A very Scientology-inspired organization is a front for a cult to bring a transdimentional horror into our universe. They use a shiny office building and a biological research complex as a front to make money required to maintain a cloning complex, which they require to produce sacrificial clones to maintain the mind/spirit/something of a possessed man, essential in contacting the aforementioned transdimentional horror. [Answer] # To Minimize Public Knowledge of the Cult > > But I do not think my life will be long. As my uncle went, as poor Johansen went, so I shall go. I know too much, and the cult still lives. > --*Call of Cthulu, H.P. Lovecraft* > > > The Cthulu Cult cares very much that its operations remain undiscovered. So much so that they killed Johansen, a man that many would have simply dismissed as crazy. In the 1920's, their loose cult of sailors, servants, and slaves was able to track down and discretely eliminate people who knew too much around the world. It follows that in a modern day setting, with a huge population increase, they'd need to be far more organized, with databases full of people they're keeping an eye on, Eldritch AI analyzing social media posts to sift the crazy conspiracy theorists from those who have actually stumbled upon the Truth, Artifact Management to secure and eliminate evidence of otherworldly *bas reliefs* and/or statuettes, Incident Management, Human Resources, Livestock Procurement, and so on. [Answer] ## The Lunar Calendar! It may be necessary to have concentrated emotions line up with a anchint calendar. The need for the office becomes more appertain if the summoning ritual requires these emotions to be repeated in the same location. Lets work back from the summoning itself. 1. The summoning is completed when their is a mass feeling of fear. This is accomplished through the laying off of all employees. Could easily be accomplished by a mass murder how ever, who rely wants to get that much blood on there hands. 2. (a day before the summoning) The ritual calls for 50 people to maintain a sense of frustration or the next 10 hours. Good news team we are all working extra hours to learn our new agile work flow!!!!! 3. (half a moon before summoning) A large amount of lust can easily be accomplished through setting up a rather intense office party! 4. And so on --- This may need to go on with the same group of people, priming them for there eventual demise. All in all the need to prep a location bye charging it with emotions could be accomplished very easy with an office environment! If you have any ideas on what emotions can be triggered bye different activities please comment below. Thanks for your time! ]
[Question] [ I'm looking for a scientific explanation as to why vampires would be incapable of entering a human's house uninvited. There have been many terrific scientific explanations for some of the most interesting vampiric traits over the years, but this is one that I'm unable to find (Google, Stack Exchange). In my world there's the beginning of a vampire society, and some vampire resistance to sunlight, so I'm interested in other ways of hindering these otherwise super-powerful blood-suckers. In a bunch of classical stories, vampires do have this limitation that prevents them from entering a decent folk's house without an express invitation. They hang out in the doorway, looking all innocent and politely asking if they may come in. If the good but foolish virgin/elderly/child says "Do come in, what can possibly go wrong" - vamp goes in, blood comes out. This limitation is usually attributed to a measure of holiness (sanctity of a place of residence) vs. the vampire's unholiness, or a magical physical prevention trick. In one short story, I recall that the vampire was unable to enter a shabby hovel before being invited, even when pushed into the entrance by a powerful ogre. But I'm looking for a scientifically (can be soft science) explained vampire, such as in these neat questions and answers: [How much blood does a vampire need?](https://worldbuilding.stackexchange.com/questions/17087/how-much-blood-does-a-vampire-need) [Plausible explanation for lack of reflection in a mirror](https://worldbuilding.stackexchange.com/questions/7117/plausible-explanation-for-lack-of-reflection-in-a-mirror). I was thinking about a psychological disability, but psychology is shifty and can be changed. Then I thought of a selective force field, but those can be hacked/altered. I really would like to have a physical, improbable to alter reason for a vampire to grind their teeth and be unable to take an extra step into my residence. (enter virgin/elderly/child voice here:) Help! Scientific heeelp! [Answer] I think you can approach it from three different avenues, depending on the tone of your setting: **Psychological:** Perhaps the root cause of vampirism in this world (such as a virus), inflicts an extreme form of OCD, hardwired into the vampire's brain. The vampire would be *physically* capable of entering someone's home, but they'd have an extreme, irrational aversion to doing so without an invitation. The hardwired OCD could be a side-effect of one of the benefits of vampirism: ie, the same neurological change which allows superhuman senses/reflexes could cause this specific type of extreme OCD. **Physical:** If you need the barrier to be *physical*, then I think the best bet would be a form of psychic influence. Similar to the psychological option, this could be explained as an unfortunate side effect of one of the vampire's powers. For example, if the vampires in this world have the ability to perform mild mind-control, then their ability to "transmit" thoughts could also leave them vulnerable to the uncontrolled psychic emanations of humans. A human in their own home would have a sense of psychic safety and confidence in their surroundings-- this causes a strong psychic field which prevents the vampire from breaching the boundary of the home. When the human invites the vampire, they weaken their psychic defenses and allow the vampire to approach. The benefit of this method is that it could also explain the effect of holy symbolism on vampires: someone with sufficient faith would essentially have a powerful psychic field around themselves at all times. This field could cause severe injury to a vampire who got too close. **Legal:** I think this would be the weakest option, but it may fit in with the nascent vampire society mentioned in the original question. Vampires would have no physical block against entering a human's home, but the law of vampire society may strictly forbid such trespass (possibly due to an ancient treaty with humans?). In this case, any vampire who violated the law would be viewed as the lowest form of criminal by their peers, and subject to execution, and possibly other harsh punishments beforehand. This option would work best if the vampires in this world do not need to kill to feed, so any vampire who breaks into a human's home to attack them would be considered a criminal to begin with. [Answer] In the novel [Blindsight by Peter Watts](https://en.wikipedia.org/wiki/Blindsight_(Watts_novel)), vampires have a neurological "glitch" that sends them into an epileptic fit whenever they see a right angle. Presumably the wiring of their visual cortex gives them a very unusual power of perception, but comes with a price. This is called the "crucifix glitch" and the idea is that in nature perfect right angles are very rare, so this glitch wasn't selected against. I thought this was a brilliant explanation of the crucifix aversion, but you could also utilise it for the invitation problem. After all doors and windows have right angles, so a vampire with a crucifix glitch couldn't pass them with his eyes open. The only way a vampire could enter a house would be, if he was lead by the hand or directed by voice, with his eyes closed (Or possibly with his eyes open, but his vision switched off …). So basically when our nasty bloodsucker comes into a little village, he has to switch off his vision, right angles everywhere, and proceed by hearing alone. Now he can do this a lot better than a blind human, in fact you wouldn't easily notice that he can't see, but he is still severely handicapped. It wouldn't do to be caught creeping around, touching walls searching for a way in or attacking humans in the open. His only shot at getting a pint of blood, is to be invited into the safety of a house by somebody he can overwhelm even blindly without making much noise. Enter "the good but foolish virgin/elderly/child" seeing the traveler walking down the middle of the road, looking all forlorn … So basically the invitation is necessary for two reasons: The vampire needs to hear a voice that leads him through the door without appearing blind (people are incredibly suspicious of the blind in these parts). And people have to let him into the house without making a fuzz, because without his vision he would have a hard time to escape from the horror of right angles that is a village. Only once he is behind closed doors with the "good but foolish" can he strike. Edit: Did you ever wonder why they build houses like this in the old days? Now you know. [![OldHouse](https://i.stack.imgur.com/JLmss.jpg)](https://i.stack.imgur.com/JLmss.jpg) [Answer] ## It's a partially misunderstood half-truth ### Short Version: Various chemical compounds traditionally used in incense and other religious ceremonies are **highly allergeni**c, even occasionally deadly to Vampires. At the dawn of Christianity, a practice developed to **sprinkle the houses of the believers with these 'blessed' substances** at least once every year. Those wanting to deal with the undead would have to purify their homes and remove all traces of such compounds, before these powers would deign to enter their homes. Hence, "inviting the devil into your home." ### Full Story: [Speaking as a **Transylvanian native**](https://worldbuilding.stackexchange.com/questions/11173/could-an-unusually-long-lived-being-continue-to-learn-with-the-times/11203#11203), I believe I am quite well-positioned to answer your question. The origins of the **Great Prohibition** (as it is known among the unliving) date back about seventeen hundred years, when a Sublime Alliance was formed under the great Undead Prince Atilla the Hun(gry), who then conquered much what of is now Europe and then led a cleansing invasion against Rome itself. It was a thing of *beauty*, decadent Roman army after Roman army collapsing under the unliving onslaught, with Vampire princes leading vast armies of Ghouls and Alghouls against the living. ... Ahh. Sorry, got lost in reminiscing there for a moment. Yet the hour of our greatest triumph carried the seeds of destruction within. The Pope, who at the time was a puny little man going by the name of Leo, subsequently called by historians "Saint Leo the Great", received word from certain Northern Shamans that were appalled at the brazen Unliving intrusion into the world of the living, breaking with the subtler approach of countless centuries. As it turns out, a certain molecular compound, trace amounts of which are contained in **Myrrh, Frankincense** and other rare compounds are likely to cause a severe **autoimmune reaction in the modified globulin compounds present in vampiric blood**, such that even skin contact or trace amounts on wood would cause the mother of all allergic reactions. The Pope met Atilla on the road to Rome. Historical tradition has the pope begging for his city, but that was mere face-saving by the Hun. In fact, the Pope revealed that all homes in Rome had been doused in Frankincense and Myrrh, making the city literally lethal to approach. As you can imagine, the practice quickly spread, with Atilla himself murdered only months later by the expedient method of having his last 'wife', an Ostrogoth princess called Ildico, perfumed in 'holy' water before being sent to his tent to be devoured. More such indignity followed, and The Hun empire collapsed like a house of cards in the face of such potent bio-weaponry. The unliving reverted to the subtler approach of older times, and all was well with mankind. The 'blessing' of houses has since ceased (thankfully) for the largest part, but is still occasionally done in Orthodox communities: [![priest w holy water](https://i.stack.imgur.com/ijN2s.png)](https://i.stack.imgur.com/ijN2s.png) Smug priest splashing deadly poison around This simple practice made European homes inaccessible to the unliving for a millenium and a half. Of course, witches and warlocks that still had dealings with the unliving would have to **take special steps to cleanse their homes of such trace fragrance**s, which later evolved in the popular lore as the concept of "inviting" the devil in your home. Silly, really. [Answer] ### Determination to adhere to traditional rules of courtesy The world's maybe most famous vampire in literature received his guest with the well-known words: > > Enter freely and of your own will! Come freely. Go safely. > > And leave something of the happiness you bring. > > > It is usually agreed that Stoker's intention behind this solemn wording was to make the Count appear unworldly and to give him a testimony of ancient times long past when these words were presumably a formal greeting that described a certain code of conduct both for and towards guests, which indeed exists -- in many variations -- in several ancient (and present) cultures. Traditionally, anyone violating the laws of hospitality (Atreus and Thyestes come to mind) was considered damned1. This code of conduct demands, among other things, that a guest may enter and leave your house freely and safely, unharmed. It *also* requires the house owner to give shelter to a wanderer, and it demands that one does not enter a home *before giving the host a chance to speak out this invitation*. Since vampires are thought to be immortal, it is reasonable to assume that they are, on the average, *rather ancient*, and so are their memories and their conduct. It is thus reasonable to look at them much in the same way as one would look at a medieval paladin -- following such a code of conduct, and merciless submitting oneself to its rules regardless what the consequences may be. Although *highly* doubtful, we know from the tales of old that a knight would rather perish than show cowardice, rather burn than tell a lie, and rather endure the worst punishment than break an oath, or fail to show justice or mercy. In the same sense, one should assume that a vampire *could* most certainly, and easily enter a house without being invited. However, this would violate their code of conduct in a sheer unimaginable way, and they would rather perish than do that. --- 1Which is a somewhat ironical thing, seeing how the subject is on vampires. [Answer] The vampire could merely *choose* not to enter without permission. Not even by compulsion, but by rational thought. Perhaps the "curse" reveals the vampire's true nature if they were to enter their prey's home uninvited. The element of surprise is critical to a clean and efficient hunt. Should the alerted prey somehow escape, the vampire's presumably hidden identity could be revealed to the community. A vampire might wisely choose to wait until they're invited and can approach their prey without suspicion. A code of honor could also drive this kind of behavior. Brute force is violent, messy, barbaric, and far too easy with the vampire's superior strength and resilience. A vampire worth their mettle earns their meal by subtler, more sophisticated means. It's easy to believe that vampires who default to assaulting their prey are considered improper, rude, immature, simple, backwards, etc. Playing the game could enhance the flavor or actual effects of feeding. Pheromones used to subdue prey might only work if the prey is both calm and very close for some amount of time - impossible to achieve without being welcomed into proximity. Those same pheromones might also drive biological changes in the prey, e.g. releasing serotonin or other pleasure chemicals into the blood, or triggering metabolic processes that make the blood more palatable or digestible. The prey's emotional state might affect the taste or effect of their blood, so most vampires probably prefer to avoid heightened emotions (or even attempt to rouse very specific combinations of emotions for a specific flavor). Being typically very old and worldly, perhaps they are just bored and looking for a challenge. Or maybe they're psychopathic and can only find the pleasure of cordial social interaction in the people they prey upon. [Answer] [This answer](https://worldbuilding.stackexchange.com/a/7119/6379) by [Philipp](https://worldbuilding.stackexchange.com/users/224) suggests a world where doors are operated electronically, and vampires don't trigger the sensors to open the doors the same way that humans do. The only way to get through the door is for someone else to open it for them (essentially "inviting" them in). In his scenario, the vampires are actually invisible, and simply psychically project an image of themselves, which explains why they don't trigger the sensors (and why they don't appear in mirrors as well), but it could be something different as well. * Perhaps vampirism is caused by a virus of some sort, and doors are programmed to detect the virus and refuse to open to anyone carrying it, to prevent an epidemic. * Perhaps vampires give off (or reflect) some type of radiation invisible to the human eye, but which blinds the door sensors. (e.g. infra-red or ultraviolet rays). * Perhaps the door sensors do a retinal scan, or some other type of biometric scan, and the vampires are altered enough from humans that they don't register as human on the scan. [Answer] I hate to bring the Bible to a science-based question, but the answer to this one could be biblical; specifically, Exodus 12:23, where lamb's blood upon the door frame instructed Death to not enter. Perhaps in a world where vampires are governed by scientific processes, biblical phenomena are also supported by (as of yet undiscovered) scientifically-measurable causes. If so, and if the force which animates the undead is be strongly associated to the force of death which struck down the first-born Egyptians, then the ancient science of that lamb's blood might bind vampires as well. It would require a little tinkering with history to spread the affect across all doorways. Maybe an Egyptian vampire wandered through the front door of an abandoned Israeli hut soon after the exodus and got incinerated by the leftover lamb's blood. Ever since that day, all vampires have avoided family doorways out of superstition and fear, not realizing that the danger was in the blood, not the doorway. [Answer] Vampires are extremely territorial. For a vampire to enter another vampire's territory uninvited is an act of naked aggression that will be met with immediate and unrestrained force. This generally benefits humans, as the secretive nature of vampires means they cannot be sure which homes are claimed by another, unknown vampire, who might ambush them while they are vulnerable in the act of feeding. The invitation serves two purposes. Firstly, it serves to soothe the vampire's instincts that warn against leaving its own territory. Secondly, it indicates to vampire that the home is not part of another vampire's territory. Through subtle hormonal alteration applied directly into the bloodstream, vampires affect the dispositions of the humans upon which they feed. A drawn human will become reclusive, suspicious, and share the vampire's extreme territoriality. The invitation to enter, given without duress, is a clear signal that the human does not live in a dwelling claimed by another vampire. [Answer] Self-hatred: Perhaps the vampires actually despise their own actions and what they have become. In an act of self-justification, they feel that if they are invited in that they have permission to do what they need to do. Sort of like a member of an organization that hazes initiates and justifies it by saying "That's what I went through when I was new". So the vampire thinks about their decision to allow entrance to the vampire that turned them, and justifies it: "It's not my fault. They bring this on themselves, as I brought it upon myself." Lack of power: Perhaps vampires really don't have any great strength, can't turn into mists or bats and fly, etc, etc. They're actually rather sickly except that they have fairly strong psychic powers. Not so strong as to be able to overpower someone who stands up to them with a clear mind, but strong enough to overcome the weak or clouded mind. Considering their strangeness, most people get a "bad feeling" about them, but those who are weak or inattentive enough to invite them in are weak enough to be overcome psychically. A test: Perhaps vampires can control some minds but not others. It's a genetic thing, like having allergies. The request may be anything unusual, not just entering a house, and it's a test to see if they can control the intended victim or not. So it might be, "Give me $100", or "Let me have your horse", if you're out in the middle of nowhere, but inside a home is a convenient place to commit vampiric crimes, so the house thing is traditional and useful. Drugs: Perhaps vampires have no psychic abilities at all, but rather rely on a psychotropic drug, and the request is a test of whether they were able to administer a sufficient dose. Administering it is an art (in the air, in food, etc), and you can't administer too much or the victim passes out in public, or perhaps dies and is toxic, so you need just enough to assure compliance, but not so much as to cause trouble or spoil the meal. Last, are you sure it's entering another's house uninvited. Wasn't the famous movie line about the victim entering the vampire's house of their own free will? [Answer] I like the psychology angle. Consider that perhaps they *can*, but they just *don't.* Vampires are traditionally vile creatures, and there's a certain poetry to the limitation. It mirrors a condition in the human mind of inviting one's own troubles upon oneself. It's a trope in fiction, really. At the end of the story, when the hero has lost and the villain has won (or at least it so appears), the villain gloats that the hero was in part responsible for the outcome, often using lines such as "you invited all this on yourself" or "you have nobody to blame but yourself." As the traditionally vile and poetic creatures that vampires are, maybe they appreciate the irony and use this strategy of only entering when invited to ensure that their own desire for drama (as well as food) is fulfilled. [Answer] Love? Could the 'love' in a home be unbearable for the vampire, unless an act of kindness is extended from the people in the home, i.e. being invited into the home. Love does include chemical processes in the brain. And some left-behind empathic wiring in the brain of the vampire could go into a very painful overdrive, that could be cancelled by the invitation. I know this is supposed to be scientific; I hope this is sufficiently scientific. [Answer] This is your best bet :[Radiation emitted by the human body](http://www.hko.gov.hk/education/edu02rga/radiation/radiation_02-e.htm) > > Yes, all objects, including human bodies, emit electromagnetic > radiation. The wavelength of radiation emitted depends on the > temperature of the objects. Such radiation is sometimes called thermal > radiation. Most of the radiation emitted by human body is in the > infrared region, mainly at the wavelength of 12 micron. > > > * A vampire can't enter a house when he senses hostile emitted radiation (not welcomed). * A vampire can enter a house when he senses friendly emitted radiation (welcomed). [Answer] What about the **Extended Phenotype** shown by certain parasites? Parasite Manipulation is where a parasite invades a host and then forces it into behavior outside its norm. Examples of this are: * the suicidal drowning of crickets infected by hairworm, a behaviour that is essential to the parasite's reproductive cycle. * female mosquitoes carrying malaria parasites. The mosquitoes are significantly more attracted to human breath and odors than uninfected mosquitoes. * ants infected by a fungii called cordyceps. These ants will move down onto the jungle floor out in the open (a complete anti-survival trait for them) before becoming immobilized by the cordyceps which then bursts its spoors over a wide area to infect more ants. In short, your vampires might be hosts to some killer virus that alters their metabolisms to feed off of blood. As a bonus, it heightens their senses, increases their reflexes and strength and their ability to heal. In payment, it 'abhors' certain kinds of smells, perhaps the pheromones emitted by uninfected humans when they feel safe cause the virus to avoid the area and instead prefer areas where humans are emitting sexual pheromones (such as near a bar or maybe where prostitutes hang out). This would be way beyond deep at a near instinctual level and would be extremely hard for an infected vampire to fight or ignore. [Answer] [Why do vampires have to be invited in?](https://scifi.stackexchange.com/questions/65991/why-do-vampires-have-to-be-invited-in) –SciFi.SE > > It depends on what vampire literature your reading. > > > --- (below is my deleted answer to the linked question) **The fifth tradition: The Hospitality** Honor one another’s domain. When thou comest to a foreign city, thou shall present thyself to the one who ruleth there. Without the word of acceptance, thou art nothing. [whitewolf.wikia.com](https://scifi.stackexchange.com/questions/65991/why-do-vampires-have-to-be-invited-in) --- Greece is one of the oldest [source](http://www.answers.com/topic/vampires-in-greece)s for the contemporary vampire legend. It produced the first modern writer on vampires, Leone Allacci, in [1645](http://www.afn.org/~vampires/timeline.html). [Xenia](http://en.wikipedia.org/wiki/Xenia_%28Greek%29) is the Greek relationship between two people from different regions. [Hospitality] allowed for the members of the relationship to safely travel into the other member’s territory and receive a place to stay and **something to eat**. -[The Value of Hospitality](http://www1.union.edu/wareht/gkcultur/guide/8/web1.html) It's the same reason Highlanders don't fight in church. It's not that they can't, they just don't. Conduct is very important when you're immortal. > > So, entering one's house without permission is a faux pas that they won't commit, but they'll murder the same person? Vampires have a very strange definition of "polite". – phantom42 > > > The host is honor-bound to sustain (feed) you once you're invited in. Proper guests do not disrespect their host by declining dinner, thieve, nor break and enter. My point is that once you invite them in (they can't break and enter anymore), it's no longer murder and they can no longer thieve the sustenance they need from you, as it has been freely and automatically offered up due to the standard protocol of hospitality. "Welcome to my humble abode," is the equivalent of signing the dotted line on a contract with the devil. [Answer] **Vulnerability:** The vampire needs the invitation for its own protection. (Admittedly, this idea sprang to mind after seeing some of the options listed by [Liesmith's answer](http://worldbuilding.stackexchange.com/a/39846/15821).) It could be that humans leave behind some sort of evidence of their residence; either a scent, or something similar that supernatural beings can detect with a sense we don't. However, just as the substance of oxytocin is claimed to affect trust and hormones are a real physical trait that impact people's emotions, this is sort of the same concept (possibly going in a reverse direction) -- the real physical acts of letting down one's guard and entrusting a person cause a physical impact on the world. Humans are not quite so affected by the resulting aura, but a supernatural creature does benefit. Sleep tends to cause one of the ingredients in the air (which might combine with some other ingredients to cause the barrier), so places like homes and hotel rooms are saturated with a protective element that you don't find in a sports arena or a grocery store. This might be combined with Liesmith's concept of Legal impact. The idea of the "legal" threat could come from peers like he mentioned, or some other supernatural power. Perhaps vampires know that their actions, considered horrendous by the victim species known as humans, are actually condoned by divine ruling. The vampires know that their actions will be traceable, because biting a human will leave a residue which is easily traceable using supernatural methods (or even a method that a natural being can use, if they have the supernatural equipment and/or know-how), so the vamp cannot effectively deny being in the presence of the human. Alternatively, instead of a legal threat from another species, the chemicals in the air could reduce the vampire's strength or increase its mortality, so that even a child could kill a vampire. (This might be caused by a side effect; if the vampire violates the supernatural law, not only is he weaker than a child, but the resulting air chemical is likely to cause intense hatred within the human, causing an otherwise-normally-peaceful human to want to kill any supernatural creature, even if the human doesn't rationally know that the creature is supernatural. Such a setup might be useful for one vampire who exploits the rules to get another vampire in trouble. By violating the rules, he causes another nearby vampire to be detected as the vulnerable recipient of lethal hate.) [Answer] My two cents: Vampires are politicians/salesmen. Yes, in the concept of world building one needs to accommodate the physical nonsense of vampirism such as how much blood is needed for a vampire to live, where they sleep, what kind of capes they wear and all that superficial bullshit. But looking at the historic presentation of vampirism over the ages, all of the behavior comes off as classic “wolf in sheep’s clothing” politician/salesman behavior. And if you think about the value of legends and myths in a society, it’s fairly easy to see someone describing a politician/salesman as someone who is a “monster” that “promises you everything but sucks you dry” has a “insatiable appetite.” Yes, there are some politicians/salesmen that use bullying tactics and brute force to get what they want. But are they more or less common than politicians/salesmen that convince their next “victim” (aka: client, market, constituent, sucker, etc…) that they want what they are selling? And in general in life, isn’t it easier to get someone to do something for you as long as you consider it’s being done in their own best interest? If a vampires hungry, just go and attack some schlub at a tavern, drain him dry and leave his corpse for the rats. But you want to recruit a new vampire for your army of underlings? Befriend them… Seduce them… Promise them eternal life… Let them live forever! As not only a monster, but a slave to a larger monster… They’ll get what they wished for and much, much more! [Answer] **This is the result of a blood pact with humans.** A long time ago, so much that noone but a few of us remember it, when vampires (and humans!) were young, there was a fierce war amongst the two races. It ended with the *Peace of the resting places*, and one of its most important provisions was that vampires would no longer enter into a human home (unless invited to do so). *(It also forbid humans from killing a vampire during the day, but they were not so constrained by the Pact and breached it)* The tales of humankind tell that they had powerful wizards amongst their side, that led them to the victory, and ―after vampires surrended― imposed such spell upon them. The informed reader will inmediatly recognise this as pure fantasy. There's no way the human forces (already quite weakened after the many deaths *just for fun* by some irresponsible vampires, which ultimately led to the cities joining against us in such war) could have defeated the vampire army. And even if such thing could have occurred, it would have been a very stupid move, should they have held such power. The complete annihilation of vampires ―which was their original goal― would have been a more sensible move. Or had it resort to such “magic” prohibition, not killing any human or banning entrance to any city would have been much wiser restrictions. Truth to be told, vampires could have easily wiped out all the humans. In fact, the problem was that they *would* have wiped out all the humans. Leading to starvation of (most) vampires on the upcoming winter. Presenting the result as a defeat, ending with this "peace treaty" was a genius movement by our leader: * it made people felt secure and diminished their motivation to fight back * rebellious vampires would not be able to indiscriminately kill food, as it would be safely stored at their homes * at the same time that it only provides a weak protection from us to human beings not to mention some other perks that human agreed to provide us as tribute :) **Update**: The assumptions here are that * A vampire can't break a blood pact * Due to their vampiric nature, blood pacts are transitive. You are affected by those affecting the vampire that *converted* you. As this event happened in the early beginning, it affects pretty much to all the vampire community (but leaves room for having a few vampires immune to it). [Answer] It could be a spiritual obstacle, since vampires are creatures of pure 'evil' and a home is a place of spiritual strength and warmth. Once the owner gives permission for 'evil' to enter the home, the spiritual lock is broken. Similarly the vampire reaction to the crucifix is an extreme reaction of a pure 'evil' being to an object holding strong powers of 'good'. [Answer] Several authors have said that their vampires have a problem because of the innate power true homes acquire over time. This leads to the implication that the less time you spend in the home, the less power in its domain it has. In fact, Jim Butcher shows a demon trying to get into his home and notes that the power of his home would hold off the demon for a little while but not forever. ]
[Question] [ I've built a time machine and it works in unmanned testing... sorta. I tell it to go into the past, it disappears, and then comes back to the present. The problem is that it isn't terribly accurate. I need to know how far back it's going in order to calibrate the "Time Selector" dial. I need a device that can determine the time across millions of years. So far I've used a [radio clock](https://www.nist.gov/pml/time-and-frequency-division/radio-stations/wwvb/help-wwvb-radio-controlled-clocks) hooked up to the onboard computer, but I want to send the machine back more than a few years. I have a pretty big compartment (6x6x7 feet) to fit the device. I'm still in the unmanned testing phase, so everything has to be automated. I can put sensors outside the vehicle (star detectors, antennas, etc). My time machine stays in the past on a 24 hour timer. Assume there is no multiverse ([it makes testing harder](https://worldbuilding.stackexchange.com/questions/67346/how-to-test-a-time-machine)). And assume that all of my testing is being performed in a desert area of the American southwest. [Answer] If you can deploy a good quality, wide-angle telescope and take photos of the night sky over a period of more than a few days, you can determine the time down to seconds over a wide range of history. It would probably be good in the range of a million years pastward or futureward. The technique would be, first, to get a basic orientation by finding recognizable stars. We know what stars are bright and close enough to have significant proper motion (PM) and what stars are bright (probably better than 8th magnitude) and far enough away to have little PM. This gives us a set of bright stars whose proper motion we know well enough to have known tracks through the sky both forward and backward from today. We spend significant computer cycles to find the set of bright stars in the photos which are consistent with those motions. This gives us a date that's good to within 1000 years or so. Perhaps more importantly, it gives us a solid coordinate system, since some of the sources are extragalactic and don't move significantly in a million years. We can cross-check this with the measured locations of the poles over the range of dates where the precession is predictable. Given that, we then can do a fitting of the observed motion of the Moon and planets to that period. The motion of the planets should tie the date down to a few days, and the motion of the Moon ties it down to a few minutes. Sources of error: (1) It's much easier if you can be sure of getting extragalactic point sources. Some of the LMC sources would be great if you're in the southern hemisphere. There's probably some decent sources in Andromeda, though it may not be realistic to have a telescope big enough to resolve them. Best would be if you could get down to magnitude 13 and pick up some quasars such as 3C273. (This ought not to be hard.) (2) I don't have a solid number for the rate at which planetary motion prediction become too unreliable. Given that we don't see chaos for a hundred million years into the future, I'm estimating that position calculations will be accurate for at least a million years. (3) The device needs to be stable over the period of observation and have a view of the night sky. [Answer] Instead of having the device determine the time it is sent to, have it leave something in place, that you can find in the present to determine exactly when in the past it traveled. This is best if your location is very isolated (or underground in a stable rock formation) to minimize the chance of disturbance during the intervening million years. The simplest I can think of is to leave some known amount of long term radioisotopes and use a detector in the present to determine the amount of decay, something similar to how carbon dating works. You should choose isotopes with appropriate half-lives to allow you to very accurately calibrate how long the sample has aged. If you want multiple trips, you should ensure that the isotopes are well sealed in a container (fused in glass or other long term storage method) to prevent contaminating the whole area, so you can measure multiple samples. [Answer] You need to know when you are sending stuff, not how much time they stayed in the past (from their perspective). So sending clocks is a no-no. One way you could do it is by collecting air samples from the past. When it comes back, compare the concentration of atmospheric gases against those of [Antarctica's ice cores](https://en.wikipedia.org/wiki/Ice_core). The oldest ones are 2.7 million years old. If you need to go further back, you may wish to measure the distance from the Earth to the Moon [with a radio transceiver](https://en.wikipedia.org/wiki/Earth%E2%80%93Moon%E2%80%93Earth_communication). The Moon is getting farther away from the Earth [at a steady, known pace](http://curious.astro.cornell.edu/physics/37-our-solar-system/the-moon/the-moon-and-the-earth/111-is-the-moon-moving-away-from-the-earth-when-was-this-discovered-intermediate) (3.8 cm/year). You may need to wait a full lunar month to get your distances right - if you wish your machine to spend less time in the past, you can also measure the time an Earth day takes in the past. Eath days are getting steadily longer with time (2 milliseconds per century, also mentioned in the last link). You just need to measure the time between two consecutives sunrises. [Answer] Assuming you can't take a star fix for whatever reason (during some of these time periods, Earth's surface could be pretty hazardous, and I'm not sure what precautions your time machine uses to avoid popping up in the middle of a rock, or a cave, or a sea of lava), your probe should still be able to take measurements of the atmosphere and magnetic field around it. Then when it gets back to your time, you'll have to compare that data to known values from Earth's past. The good news is that we carry out the same process on fossils and rock strata *all the time*, in the study of [stratigraphy](https://en.wikipedia.org/wiki/Stratigraphy#Chronostratigraphy). All the reference data you would need is well-studied. The bad news is that it's *much* less accurate than an astronomical approach, probably on the order of tens to hundreds of thousands of years. However, it has the advantage of allowing a much tougher probe compared to a delicate telescope. You could use the two techniques together, if you felt the need. Stratigraphic fixes would let you safely determine a very rough timeframe, which will tell you roughly what geography to expect. For instance, during some past eras, much of North America was covered by a shallow inland sea - not exactly ideal for astronomy. Knowing when your probe will pop up allows you to choose a location you know will be suitable for the more delicate equipment. It also gives you a good feel for what the atmosphere will be like, so your telescope probe can take that into account. [Answer] I'd say go back as far as you could possibly want to and leave an atomic clock (or several for redundancy). When it wears out / breaks replace it with another. Eventually you'll have a continuous line of clocks from the dawn of time Once you have a line of clocks right up to modern time, you can tell exactly when you are down to the microsecond. You can leave it on land, bury it or have it floating around in space or even on the moon. [Answer] Similar to measuring star positions but not reliant on any particular set of stars/location. Use the [expansion of the universe](https://en.m.wikipedia.org/wiki/Expansion_of_the_universe). This should provide you with a known rate which you could plug into your *time selector* using hind- or fore- casting algorithms. You have a time travel device, I'm assuming you have something powerful and portable enough to measure or record two distant parts of the universe, to get a reading. [Answer] So, here's a suggestion which should cover a wide swath of destinations. NASA recently developed a method of locating any spacecraft to within a few miles within the solar system, [by using the position of known pulsars](https://www.nature.com/articles/d41586-018-00478-8). This is great for location in space (perhaps well outside of just the solar system), but the catch is that they are, gradually, changing their frequency. The Crab Pulsar, as an example, is spinning down at a rate of 3.7e-10 Hz/s. By identifying these pulsars, comparing their relative frequencies with those in the previous temporal position, and mapping their position (given that their velocities are also well known), you could get a reasonably precise location from hard-to-miss stellar bodies. What would be even better is to combine the data regarding their spin-down (or spin-up, if you're going into the past) with trajectory distances and perhaps additional clues such as broader star movement and geomagnetic data, minimizing error in the result by taking a weighted average of known error. This would all be without the need for an internal device, beyond simple precision sensors, and could get you pretty good precision. The only points at which it would fail would be extremes where the pulsars weren't formed yet (which is pretty exhaustingly far out), or in locations far enough from known space where the pulsars could not easily be found in the sky. ...I would suggest filling the remaining space with a comfy couch and an entertainment system for the trip. [Answer] Since the earth and the sun move and rotate through space, too, I'm afraid you'd have to use a space-time machine, leaving you only with the ability to test whether you have hit the space-time coordinates you're aiming for. One test-run would then look like this: * Calculate where in the universe the earth would be at the time you choose. * Send your space-time machine to these space-time coordinates. * The machine tries to find earth and measures the distance to it while triangulating its own position using known stars. * After returning, the data gives you your error margin. Of course, you'd have to account for accidents like "there is molten lava outside the time machine" or "the time machine is a mile high up in the air and about to crash" or "the time machine has a vastly different velocity vector than the earth". Or, you get around all that and assume your time machine is gravity-bound the whole time it is in transit. [Answer] # Genetic analysis of ground life form First, sample the DNA of as many commun ground dweling fungis (or any eukaryotes) as you can. If you have no access to the night sky, you could dig to find the same species (more exactly their ancestor) and measure the number of change, especially in the Non-coding DNA. This can give you some estimation of the time between your departure and "now" This method can work while traveling in the past or travelling the future. But I am afraid it can not tell you if you travelled 1000 years in the past OR 1000 years in the future. Safe travel to you! [Answer] **Use Radioactive Decay** Similar to Josh's answer, If you are capable of building a time machine, you should be able to build a small automated robotic device that can simply move out of the time machine, take a soil sample, then return to the time machine and perform analysis on the soil using spectroscopy. Almost all soil around the world will have a small amount of natural uranium that you can analyze to check the ratios of U-238 and U-235. This is one method for determining the age of the earth, and it should do well to determine how far back your time machine went when comparing to modern ratios. [Answer] 1) Send your time machine from the present to random times in the past when there were already radio broadcasts. 2) Measure the used fuel every time. 3) Wait until one of the radio broadcasts tells you the time for determining the exact time you have arrived in. 4) Calculate the relationship of time travelled and fuel used. 5) Once you have a working equation, test your time machine with travelling between past times to test whether the equation holds up if your point of origin isn't the present, and rework the equation if needed. [Answer] Are there any trees nearby? Dendrochronology could be used on species like bristlecone pine that live thousands of years. Beyond that, sediment layers in mountain ranges. You could potentially have a record of tree rings going back 10,000 years if the research has been patched together. My main concern with time travel though is that you would move into the future or the past at the exact spot in spacetime, but the earth and solar system relative to that spot would be millions of miles away, or more. Maybe you have to aim the time ship in the direction of where the earth is at the destination’s time. [Answer] ## Continental drift I think a cheap way of doing it, yet giving a more or less precise reading, is to look at the position of the continents. [They are moving slowly](https://en.wikipedia.org/wiki/Continental_drift), and we have a [rather good idea of where they were at which time](https://en.wikipedia.org/wiki/Geological_history_of_Earth), as well as their speed of travel. You could send an [high altitude balloon](https://en.wikipedia.org/wiki/High-altitude_balloon) to get pictures and process them when the machine gets back. Try to have a system that sends the pictures from the balloon to your machine, it's easier than to retrieve the balloon. [Answer] # Use the star map for short time, use the expansion of universe for longer time ## For a few million years Other answer deal with it pretty well. You can see the star map at night, you can compare air sample with air trapped in Antartica (works only for travel in the past) or human radio emision (work only in near future) # From 100 million years to a few billion years: [red shift](https://en.wikipedia.org/wiki/Redshift) of distant [pulsar](https://en.wikipedia.org/wiki/Pulsar) Even if you cannot predict the exact trajectory of star/galaxies on the very long run, you'll still be able to locate a few pulsar. Even after several billion years, the frequency of their pulse should not change much. And if you have a doubt, their relative position should also be similar. Most distant object will not move by several degree even in 10 billion years, so a pattern of 5 pulsar will still look the same( Worst case scenario, there are only 4 left). So, you'll be able to spot a few pulsar. You know the wave lenth they emit nowadays. By measuring their wave length somewhere in the past/future tells you [how much the universe did contract/expand.](https://en.wikipedia.org/wiki/Accelerating_expansion_of_the_universe) Crunch a few numbers and it will give you the date. Edit: This works better if you travel in the future as in a distant past, the pulsar may not exist yet. # For eternity: [Cosmic microwave background](https://en.wikipedia.org/wiki/Cosmic_microwave_background) Curently, the Cosmic microwave background has a temperature of 2.72548±0.00057 K This decrease with time [as universe expands](https://en.wikipedia.org/wiki/Accelerating_expansion_of_the_universe). So a few computation will tell you the date. Problem: to measure this for earth surface, with current technology you'd need a 10m wide instrument. And the dificulty increase when you travel in the future. [Answer] 1) Air pollution. I believe the composition of trapped atmospheric gases in Greenland ice cores have be used to detect minute changes in Earth's atmosphere over decades, centuries and millennia, This has been used to chart the rise and fall of various industries over the ages as they pollute the atmosphere. So your time calibration package should include an automatic air sampler to bring back an atmospheric sample you can test in your laboratory to see how well it fits in with the record of Atmospheric composition changes in past years, decades, centuries and millennia. If the time machine goes back to a time within the range of scientific studies of atmospheric composition from ice core samples you should know the date within a few years or decades. 2) If you have some sort of automatic robotic optical and/or radio telescopes in your time calibration package, they can go outside and measure the important optical and radio sources during the daytime and the nighttime. The Moon can always been seen when above the horizon, day or night, except when hidden by clouds. The direction to the Moon, and the phase of the Moon, can be measured very accurately. The phases of the Moon change over a period of 29.6306 days. The planets Mercury, Venus, Mars, Jupiter, and Saturn would always be visible to the naked eye when above the horizon during nighttime, and sometimes would be among the brightest objects in the sky - Venus, Mars, and Jupiter can sometimes be seen during the day. If the telescope can tell the difference between a planet and a star, it can identify those planets that are above the horizon. So the directions to the planets, and their phases, will show the positions of the planets relative to the Earth, at the time the observations are made. For each body in the solar system, there is a synodic period, the period between the times when it's angle relative to Earth is the same. For Mercury the synodic period is 115.88 days, for Venus 583.9 days, for Mars 779.9 days, for Jupiter 398.9 days, and for Saturn 378.1 days. So if the automatic telescopes are able to find the directions to three or four planets, that will show a relatively rare configuration. A length of time that three or four synodic different periods could fit in as integers and not fractions would be a very long period of time in which each synodic period was repeated many times over. And then if that is combined with the phase of the Moon with its own cycle, that becomes much rarer. Then there are the apparent positions of the four Galilean moons of Jupiter, which would be easy to detect. They have their own synodic periods in relation to each other. That will make the day that your time machine spends in the past even more unique. So astronomical observations should make it easy to identify the 24 hour period that your time machine spent in the past or the future, for as long as astronomical orbital simulations are accurate. 3) For a much longer time span, the Sun takes about 200,000,000 years to make a full orbit around the galactic center. The center of the galaxy is the first astronomical radio source ever discovered, so it should be easy for a radio telescope to find the direction to it, if it is above the horizon. Several external galaxies, such as the large and Small Magellanic Clouds, M31 in Andromeda, and M33 in Triangulum, are bright enough to be seen with the naked eye and should be easy for a small telescope to detect. The galaxies Centaurus A and M87 are also famous radio sources that should be easy to detect with a small radio telescope. So it should be relatively easy to detect the directions to both the galactic center and one or more external galaxies, and thus determine the position of the solar system in it's orbit around the galactic center, and the nearest past or future eras that could be. 4) Send a Mars rover type robot out to collect rock samples (different rock samples in different eras, of course, since you don't want time paradoxes). Most minerals contain trace amounts of radioactive isotopes which decay into other isotopes at a rate that can be calculated. You can test the samples in your lab for the ratios of various isotopes, and if the samples are collected from far enough in the past you should be able to calculate the approximate date. And there are many similar astronomical and geophysical methods that you can used to detect the date on various long, medium, or short, timescales, and to calibrate various methods against each other to improve accuracy. [Answer] The radius of the Sun shrinks by 74 centimeters per year. The fusion reaction of the Sun converts mass into energy and overtime it loses mass. You could measure the diameter of the Sun to determine the current year. This approach has the advantage that the time machine can appear in any moment in history and calculate the current year. Assuming the rate of change in the size of the Sun is constant. It becomes a linear calculation of how much time has changed. I doubt you'll be able to calculate the exact year, but if you have the technology to build a time machine you can surely build a device to accurately measure the diameter of the Sun. Here is a reference to Sun shrinkage from Stanford University. <http://solar-center.stanford.edu/FAQ/Qshrink.html> Also, if you take a photograph of the Moon's surface. This image defines a timestamp in history. Comparing two images of the Moon's surface will tell you which image came first. As new impacts overlap old impacts. The more rapidly the surface of the Moon changes the further back in time you've gone. This isn't going to help you over small distances, but if you don't know how far your time machine has travelled, then taking an image of the Moon would be a quick way of knowing if it was a long distance. [Answer] I want to extrapolate on an earlier answer and comment: Use an atomic clock. Set the "Time Selector" dial to whereever you want to randomly send the machine, then have the automated systems deposit the atomic clock in the past. Recover the time machine. Turn the dial by, say, 1/100 of a degree forward (or adjust the dial however you can adjust it while measuring the change). Go back and read the time on the clock. If the clock is old and rusted by the second jump, change the dial so it's only 1/1000 of a degree forward and try again. Keep using smaller calibrations until you get an usable reading from the clock. Now you have two data points; preferrably far apart in time. Then, keep sending back the time machine to random times between your two endpoints. If you keep gathering samples, you will eventually have enough data points to approximate an equation to describe how much time a turn of the dial represents (is it linear, or is it some other strange model?). Find where this equation intersects with the present day, and this will allow you to find the numerical year that your time machine landed; given a good enough approximation, you could theoretically pinpoint your calibration to the nanosecond. This method has the advantage of not needing to use measurements from uncertain sources (no sky readings, no DNA samples of external organisms, etc.), but only if you can overcome the obstacle of landing in the same place over a large amount of time (preferably the same desert). [Answer] 1. Measure the [luminosity and the size of the sun](https://astronomy.stackexchange.com/questions/14535/why-is-the-suns-brightness-and-radius-increasing-but-not-its-temperature), and thereby derive its age (and in turn, via comparison with current-day values for the same measurements, find a temporal position). 2. Similar to the answer that mentions [measuring the rate of expansion for the universe](https://worldbuilding.stackexchange.com/questions/116454/my-time-machine-needs-to-know-when-it-is/116460#116460), you can measure [the redshift of gravitational waves](https://physicsworld.com/a/are-gravitational-waves-being-redshifted-away-by-the-cosmological-constant/) & compare to current-day values. 3. Again similar to the above, [measure the background radiation](https://astronomy.stackexchange.com/questions/8763/does-the-cosmic-microwave-background-change-over-time) and calculate time based on the CMB "trajectory". For a craft of any kind, space-faring or otherwise, option 1 (out of the ones mentioned here) is probably the most feasible in respect to size of necessary equipment - and can probably easily be done with equipment you can also use for some of the other answers here, like the top-voted answer that suggests imaging the nightsky, meaning you can do several different measurement types and compare the results. [Answer] I would recommend tracking the movement of key stars in the sky. Pick the correct ones, and you save yourself the need to track them all while still forming a comprehensive picture of the night sky that should not appear perfectly identical between two given times. This does limit the device to being used under an open sky, primarily at night: for obvious reasons, this isn't going to work inside a cave or a building. You're going to need a good telescope on your time machine as well, and probably regular inspections to check its calibration and accuracy (if it's unable to detect and repair this automatically). Or you can just use an atomic clock, if simply having precise timekeeping is enough in the absence of outside references. Those are accurate to within a few seconds every million years, and I don't think your eventual time-travellers are going to be too concerned about being off by a couple of minutes. [Answer] The most accurate way of doing this would be the Stars, but many people have suggested this so its best to see their answers, but i'll offer an alternate suggestion They'll be a device within this time machine which when more power or [insert plot device] is passed through it controls the amount of time traveled, for personal reasons i'll call this the Flux Capacitor FC for short. If you don't know what this device is you need to rig up several sensors to every component and run the below tests for each part just to ensure you have the right component. Once you know which part the Flux Capacitor is, then run the below tests. **Test 1**: Measure the power to the FC upon embarkation very precisely with several sensors, and take star measurements. and place a radioactive isotope on the ground. return to present **Test 2**: repeat test 1 to ensure that the correct sensor readings, if Stars match test from Test 1 (taking planet rotation into account of course) then you have a good basis to believe that your testing is accurate so far and you measuring the relevant FC settings is correct, and that your machine has the ability to accurately repeat a destination. in theory the radioactive isotope should read the same levels of emitted radiation as when you left it there as it would have only been x amount of time between transits **Test 2.5**: in theory it would be advisable to run test 2 several more times to be 100% certain **Test 3**: Reduce the FC's power slightly and embark once again, take star measurements once again. but also scan for the radio isotope, if found measure the radiation emitted from it, it should be less, on the assumption that less power into the Time Machine/FC would mean a shorter distance back in time traveled. measure how much less and this should give you an idea of how much power difference changes the amount of time traveled. **Test 4**: Repeat this transit at the same power level. always double and triple check your findings with multiple identical tests using the same power levels **Test 4.5**: return to previous power levels and run test to ensure that you return to the previously established moment in time **Test 5**: further reduce the power into the FC and perform the same test as Test 3, again this should give you a good idea of power change **Test 6**: increase the power past the initial starting point to and area your previous readings would suggest is say... 1000 years before Test 1 landed. and then place the Radioactive isotope down again and then return to the present **Test 7**, return to Test 1 levels and detect the isotope from an already established moment in time, confirm settings are as predicted and adjust for any changes Again repeat repeat repeat, these tests should give you an idea as to whether the the power requires are exponential/logarithmic as you want further back, or incremental, once you know this then its fairly simple maths to figure out, I want to go X years into the past i need Y amount of power, this allows you to know where you are going its better to know where you're going, because then you can use Star mapping as others have suggested to confirm you are where you expect to be. Just do us all a favour and bring a hazmat suit with you. not for you, but so you don't bring a modern illness into the past. [Answer] **Deploy a robot that travels to the past and buries a known quantity of a radioactive substance in the soil (in a properly shielded and tamper-evident container, to avoid detection and trouble with the EPA and such)**. In the present, dig up the container and measure how much of the substance has decayed. [Depending on which element you choose](https://en.wikipedia.org/wiki/List_of_radioactive_isotopes_by_half-life), you should be able to determine when the sample was buried -and thus, how far back the machine went- to a fair degree of accuracy. You might even bury several samples of different elements, just in case strange time-travel effects might alter some of them but not others. [Answer] ## Assumptions If you want to calibrate it, I assume you already have a way to make it go further or closer, and just need to know by how much. For example, you have a dial that goes up and down, but you have no idea if one rotation is a year or a million years. I also assume that you are using a fixed timeline (stable time loop) model for time travel, because you specifically mention how there is no multiverse, and changing the past would make paradoxes by the dozen. ## First Step First, you find an object that has been in place for, let's say, five thousand years. There are such objects on the earth, and while you might have a few legal issues bringing the time machine there if it is big, you should be able to work around it. A great example would be Stonehenge. You setup the machine to scan for a specific Stonehenge rock, or maybe the entire pattern, and do some trial and error to find a dial setting where Stonehenge exists. If your machine has the potential to go back as far as the big bang or even before, you're in trouble regardless, because the odds of you reaching the earth are so small you might as well give up now. If your range is around the age of the earth, you will need at most 908 600 attempts, so on average 454300 attempts, to find a time period where Stonehenge exists (Stonehenge has existed for 5000 years, and the earth has existed for 4 543 000 000 years). ## The trick Now it might already seem like way too many attempts. But remember, if you can automate scanning for Stonehenge, you can definitely automate trying again by changing the dial a bit. And since your machine is a time machine, it can always come back, after scanning or even after 24h in the past, to one millisecond after it left, therefore completing all those 500 000 scans (or so) in 500 seconds, or just a few minutes. Bonus: You can even add to your story the fact that your machine's attempts throughout the last million years are what caused people to make Stonehenge in the first place, because a strange device kept spawning around that place and acting weird, then disappearing. This can either be a fun fact or a plot point. ## Next Steps Once you've found at least a dial setting containing Stonehenge, you can check the number of attempts that have been required, and do a rough estimate of your dial's step size. Now you can do the same operation, but with an object that has existed for just a few years, but is much easier to scan for. Take the largest tree behind a house that has been in your family for a few generations. Explain grandma's irational alien sightings at the same time, and do the exact same process, with a much smaller increment on the dial. This should take about the same number of tries, but it is much less public and problematic. Once you've found the tree, you can again roughly estimate (but with much better precision) the dial's increment size with your two measures. You can just repeat with a one month old object that doesn't move. If there is none, you can spare a month making it, just make sure to ignore the random time machines that show up during that month of waiting. ## Figuring it out You repeat until you have a few very specific measures on the dial. I suggest more than two, just in case the progression isn't linear but something weirder like square, exponential or sin. About ten good precise measures, once you found a range of dial that is easily testable like an hour, should give you all the data you need. ## The potential problems * If your machine can also go in the future, you might "miss" the 5000 year window by a lot if your increment is a million years. If Stonehenge doesn't last that long in our future, then you might test billions of years in the future, never finding anything. **Fix:** If you don't find anything after billions of attempts, just start over with a smaller increment * After a certain number of attempts, your machine may not come back. Maybe it got destroyed during the scan in the past, or worse, captured. Since no one in the past had time-travel inhibiting tech, you can assume it got at least disabled completely, maybe by people, animals, climate or environment. **Fix:** Add a self-destruction mechanism with a dead man's switch. If the running code either fails or stops running at any point, wait 1 minute, then blow up. Make sure the blow up is enormous enough to annihilate everything, to avoid giving modern tech to our ancestors. It doesn't matter if you kill one of a hundred of them since it's a stable time loop. Also make sure you have the machine write a log every time it pops back in the present, so you know exactly where it was so you can resume testing from there with the next one. Have very precise plans to build it again if required. * Your machine doesn't compensate for earth's rotation, movement, the solar system's movement, the galaxy's velocity, etc **Fix:** Yeah you're screwed. Handwave something and compensate for earth velocity. [Answer] Are you only looking for ways to test based on the local environment? And are you trying to avoid more handwavium than a time machine already requires? Assuming yours is the only time machine, you could conceivably set yourself up a "time beacon". Set up a device in your lab that syncs with a similar device in your craft (quantum entanglement sounds sexy without actually meaning anything). By comparing the settings of the two devices, you could determine not only distance in miles from your point of origin, but in years. Such devices have been used in other stories. The Legion of Super-Heroes stories has a time beacon set up in the 31st century. [Answer] There is a much easier and safer way.. Program it to send and respond to the same signal. Send it back 100years to remain in place a few minutes and then return. Let us say you have it well calibrated to 10years but do not know exactly how well, which is why million year excursions would multiply your error and result in drift. So have the machine repeatedly send itself back 10 years 10 times. If the machine does not find itself after say 24 hours, return and assume the drift is under 10 years. Recalibrate to lengthen its concept of time and repeat. If the machine finds itself, note the delay before the first machine appears and calibrate accordingly. Repeat for 1000 years with 10 steps of one hundred. Do this then for 10000, 100000 and then one million. BONUS:The method works for future calibration too. [Answer] If you can move it somewhere else, try to go in a place where there is some ancient monument, for instance, the most ancient and known one is [Barnenenz](https://en.m.wikipedia.org/wiki/Barnenez), in France. If your time machine can find it, it means it's 4850 BC or later, if it can't find it, it's earlier. Do some attempts in a binary search fashion and you will have your time machine calibrated to that specific date (6868 years). I know it's not a long time span but it's a start. To get longer time calibration , you can place your time machine in the position where a dinosaur fossil has been discovered (possibly an easy one to find), this will give you a way longer time span. If the fossil is not there it means the dinosaur hasn't died yet 😉 [Answer] Rather than using external cues, as others suggest, you could simply fit it with an odometer\*. I.e. you don't know exactly where\* it's going to end up, but it could be capable of recording how far\* it has travelled. You set the dial to 1 million years, it goes, and on it's return the odometer reads 2.5 million years (there and back again), you know it was out by 0.25 million (plus or minus 24 hours if the odometer records time elapsed in the old fashioned way). A few taps with the spanner later and you're in business. This was pretty much the solution that H.G Wells used in The Time Machine, he controlled the machine with a lever, relying only on the 'odometer' to tell him how far he had travelled. \*temporally speaking, not geographically [Answer] You take a geological sample and do an analysis of uranium isotopes in the sample, using alpha b, mass spectrometry or maybe some other technique to obtain the isotope ratio between U-238 and U-235. As the halflife of U-235 is shorter than that of U-238, this ratio is slowly increasing. - this will easily tell you how many million years you are back, maybe within 100000 as well (I have not done the math ;-) ) - if you want to compare times a few millions ore more of years back, you may even be able to use ratios involving 236-U or 233-U - with much shorter halflifes, they will give a much better resolution 10000 / 1000 years, but they can not help you to obtain an absolute point in time. [Answer] If you consider that **[gravity](https://en.wikipedia.org/wiki/Gravitational_time_dilation) and the [magnetic field](http://earthsky.org/earth/how-earths-magnetic-field-is-changing-swarm) are not constant through time**, the machine can just accurately measure Earth's values and do the proper calculations to exactly determine the time it ended up in. There is no need for other external measuring tools. [Answer] # Fundemental problem > > And assume that all of my testing is being performed in a desert area > of the American southwest. > > > There is a fundamental problem that most time travel designers oversee. They all seem to assume that planet earth's position is at the [center of the universe](https://en.wikipedia.org/wiki/History_of_the_center_of_the_Universe#Earth_as_the_center_of_the_Universe). You are traveling through space-time. Let's say you assume to keep your position in space coordinates and you travel back or forward for only a few minutes, you are going to miss earth big time. [Wikipedia](https://en.wikipedia.org/wiki/Earth%27s_orbit): > > Earth's orbital speed averages about 30 km/s (108,000 km/h; 67,000 > mph), which is fast enough to cover the planet's diameter in 7 minutes > and the distance to the Moon in 4 hours. > > > Taking into account the speed of the solar system itself ([Again wikipedia](https://en.wikipedia.org/wiki/Galactic_year)): > > The Solar System is traveling at an average speed of 828,000 km/h (230 > km/s) or 514,000 mph (143 mi/s) within its trajectory around the > galactic center. > > > Now, this could go on taking all movements and expansion of the universe in account, but I will stop here. Point is: you will need a pretty good coordinate calculation system before you send your time machine. This can be done, if you know exactly what time you are sending it to. But there appears **the paradox**: you want to send it back in time to calibrate it's "Time dail". It is therefore impossible to put it anywhere on the planet. # Problem becomes the solution So, don't try to land in earth. Make sure that the design is capable of withstanding outer space. Send it to exactly the same space coordinates, which will put it somewhere in deep space, with the best view of the galaxy you can ever get. Now, it can do wavelength identification of our own solar system and other known stars or even remote galaxies. And based on the absolute or relative differences, you can accurately calculate the time. ## Risk calculation Before sending back your machine, try to estimate its inaccuracy. Based on the galactic model, try to keep the probability small it ends up in another star that since traveled to the same coordinates. Changes are really small, but the calculation is not difficult vs loosing your precious machine. ## More runs Do more runs, to different time frames. Try do to confirmation measurements that the galactic model is indeed correct. Each run your "Time dail" should become more accurate. Once you have enough confidence, start tuning the coordination system. Do the same range of trips, but closer to earth. Assess earth's position and own rotational speed. Try to create your own calibrated movement model, not based on calculation of modern science, but what is now actually measurable. In the final test you send it in the same place in the south-western American desert. If the machine returns in one piece (eg you did not put it in earth's crust or let it plunge down from a reasonable height) your machine is ready for human travel! [Answer] Turn off the space unit in your time-space machine (in order to avoid catastrophic failure, I'm assuming it is necessarily a time-space machine, but we don't need that part here). Travel back some "moderate" unknown amount of time (couple of hundred years, or some thousand, whichever), that will place the vessel somewhere in space. Drop off a radio beacon, go back. Receive the signal. If you don't receive anything, something went wrong (beacon destroyed, out of power, waaaaaayyyy too far into past?) - try again. Either you need a timestamp encoded in the signal (then you need to correct for the speed of light, but luckily this is pretty constant, and well-known), or you can use Doppler's Effect (then you'd need 3 beacons minimum), whichever. You could use both, and cross-validate. Calculate the distance between "then" and "now". Earth's speed while tumbling around Sun through Milky Way is known. There you go. ]
[Question] [ In *The Lord of the Rings,* the elves invented an incredibly nutritious bread/biscuit; as Legolas clearly says, only a small bite is just enough to satisfy the needs of an adult man for 1 day. An adult person needs about 2000 kilocalories per day... maybe 1600-1700 for extremely skinny and underweight people, or those who have jobs that require no physical skills. But I'm going with the 2000 kilocalories one... Each bite of lembas needs to sustain a person, so it might give 50 grams of protein, 250 grams of carbs, and enough fats to avoid protein toxicity - maybe 80-85 grams of fat can make it. So how would a medieval society create lembas without magic? Putting and compacting extreme loads of nutrients together is easy, the hard part is to make it edible, and, most importantly, not deadly. Feel free to adjust the fat-carbs-protein ratio as you prefer. but please keep it healthy and close to 2000 kilocalories per bite. What it tastes like doesn't matter, after all is just a bite. [Answer] ## It just doesn't add up if you only consider real world nutritional chemistry. The most calorie-dense food available is fat at 9 calories/gram. That's 220 grams to hit 2000 calories, nearly a quarter of a kilogram or half a pound. The volume of a closed human mouth (a clear upper bound on the meaning of "a bite") is around 45-90 cm$^3$. Lembas bread is therefore at least 2.44 g/cm$^3$ (220/90), which is nearly as dense as granite. Fat, by the way, is around 0.9 g/cm$^3$ – it floats, of course. If you assume a more moderately-sized mouth, and a healthier/more palatable composition for the lembas bread, it gets out of control very rapidly and you're walking around with bread as dense as steel. You could try a carbohydrate based bread, but sugars are less mass-dense AND less calorie-dense-per-gram when compared to fat. Proteins are variable but more mass-dense than fat ([on average less than double](http://www.ncbi.nlm.nih.gov/pubmed/10930825)), but they are far less calorie-dense than fat (less than half), wiping out the potential energy-density advantage from relying on them. You've pretty much gotta appeal to elf magic on this one. [Answer] In the books there is a bit more wiggle room : (*Farewell to Lorien*; last few pages) > > '*Cram*', he [Gimli] said under his breath, as he broke off a crisp > corner and nibbled at it. His expression quickly changed, and **he ate > all the rest of the cake** with relish. 'No more, no more!' cried the > elves laughing. You have eaten enough already for a long day's march.' > > > So in the original a **whole cake** is described as being enough for a day. Also it is described as being crisp so we can guess that it's pretty thoroughly dehydrated. Shortbread has around 500 kcal per 100g (and also fits the description reasonably well) . Even so 400g of shortbread is a lot to eat in one go but certainly not impossible. The elves go on to say : > > One will keep a traveller on his feet for a day of long labour, even > if he be one of the tall men of Minas Tirith'. > > > This isn't quite the same thing as saying that it meets your long term nutritional requirements for 24 hours. So it's not beyond the realm of possibility that it also contains some sort of stimulant etc which helps you draw on your existing reserves immediately without necessarily replacing them. This would also explain why they encourage them to go easy on it and only use it in emergencies. It is also noted later on when Sam and Frodo are travelling into Mordor that they notice that it seems more sustaining and moral boosting when not mixed with other foods which might back this up. As an aside the complete inedibility of 'dwarf bread' is a recurring in-joke in the Discworld series. First appearing as a footnote in *Witches Abroad* and greatly expanded upon in *The Fifth Elephant* and *Thud*. EDIT : there is a good point in the comments relating to what 'a long days labour' or 'a days march' might actually mean in terms of calories. First is the phrasing. Does 'a day' mean 24 hours consecutively or is it 'during the day' assuming extra meals at the beginning and end of the march/work period. I would suggest that the phrase 'keep a traveller on his feet' might imply that it is the absolute bare minimum to keep going. Survival manuals often quote 1000 calories per day as a minimum to keep active and functional (for short/moderate periods) so it's not entirely unreasonable to see 2000 calories as just about adequate for a week or so of reasonable activity. For a real world comparison the [British Army 24 hour ration packs](http://www.mreinfo.com/international-rations/british-24-hour-ration-packs/) contain around 4000 calories and weigh about 1.5kg. They are intended to provide the nutritional needs of a soldier over a period of a few weeks and so 4000 Kcal per day is probably a reasonable figure for medium terms needs for fit people doing a reasonable amount of labour. Although equally you wouldn't necessarily expect an infantry soldier to be burning through calories at the maximum possible rate for a human in this sort of period. Having said that for something which is very clearly 'emergency rations' you could certainly keep going on a lot less that this for a few days albeit with some weight loss. If fat has around 900 kcal per 100g then even a shortfall of 2000 kcal per day is only equivalent to a couple of hundred grams of body fat per day. **The film** In the film version it's Merry and Pippin who scoff lots of Lembas but as the lore of the books establish that Hobbits have very healthy appetites but also are very hardy when push comes to shove this seems like a reasonable stretching of the point both for stylistic comic relief and to make the point that Lembas is very compact calories and perhaps a bit magical. [Answer] If you want calorie density, you need fat. Fat has over twice the calorie density of carbs or protein. As long as not too much of it is saturated, you could probably survive on it. Let's take three corners of the original vegetarian diet: [whole grain wheat](http://nutritiondata.self.com/facts/cereal-grains-and-pasta/5744/2), [lentils](http://nutritiondata.self.com/facts/legumes-and-legume-products/4337/2), and [olive oil](http://nutritiondata.self.com/facts/fats-and-oils/509/2), and try to get to 2000 kilocalories and 50g protein. Since taste doesn't matter and you have all day to digest (drink lots of water!), let's used uncooked products for maximum density. If we combine for max energy, then 150g olive oil, 100g wheat, 100g lentils give you 2000 kilocalories and 40g protein. You get 100% of your daily fiber, vitamin E, vitamin K, and folate, and 50% of 8 of 16 vitamins and minerals I looked at. If we combine for max nutrition, then 60g olive oil, 200g wheat, 200g lentils gives you 80g protein, 100% of 6/18 vitamins, and 50% of all but vitamin A and C, and calcium. This combo is actually probably better nutrition than you or I get on a day to day basis, but to survive on it forever you will need a vitamin C boost to ward off scurvy, so add some tomato juice to the mix. In any case, there are probably even better optimizations (add some tomatoes, or a little bit of meat to the mix) that would get you perfect nutrition, but the problem is the weight. Even pure olive oil is 226g to 2000 kilocalories, and the nutritious option above is 460g... almost exactly one lb of food. The lembas are going to have to be made like a pizza crust, then hit with a [shrink ray](http://www.imdb.com/title/tt0097523/). Are shrink rays magic? [Answer] At first glance, the math says this cannot be done. Upon further inspection, there is a solution. A small bite is about 10 cm^3 (or 10 ml). If we want 2000 kCal, or 8MJ, this requires an energy density of 800 kJ/ml. Gasoline is very roughly as dense as water (within a factor of two) and a quite energy dense storage medium. 1 kg of gasoline is 46 MJ, so 1 ml of gasoline is 46kJ. Off by a factor of 20. To beat Gasoline by a large factor you are going to have trouble. [Wikipedia](https://en.wikipedia.org/wiki/Energy_density) basically tells us that using chemistry is a dead end. Explosives, for example, are not more energy dense, they just contain their own oxidizer for rapid self metabolism. However, that same chart gives us hope. Plutonium, Tritium and other nuclear processes have insane energy densities. The problem is that humans, or near-human things, don't metabolize nuclear fuel very well. To solve this, the elves merely have to create tiny nuclear reactors that produce digestable chemicals. The being eats the bread, encrusted with nuclear reactor powered nanobots. These bots consume raw material in their environment and reconfigure them into higher energy states. If you don't bleed out from radiation poisoning or having your stomach lining converted into high-calorie fat, you are able to manage from very little food. So the medieval society merely has to industrialize and generate a technological singularity, convince the resulting post-human AIs to solve the problem and help roll back every other change. Legends of such an event may remain, with the communication between the post-humans described as some kind of song. [Answer] Complete foods are already a thing! Ever heard of [soylent](https://en.wikipedia.org/wiki/Soylent_(food))? They contain not only the calories, but all the nutrients you need in your RDI. Some even look like biscuits and energy bars, like the [tweenybar](https://www.joylent.eu/products/twennybar) and this [one](http://www.mealsquares.com/). Packing all those calories in a smaller biscuit or even a single bar doesn't look very feasible, and even if it was the result would be incredibly dense and hard to ingest. Maybe some ketogenic variant would be easier since some fat can store more calories for unit weight. [Answer] **Portals** After reading @SudoSedWinifred's answer, most people would give up. However, I say why let physical impossibility be an impediment. Instead, let's think with portals. Each bite of PortalBread™ contains millions of dormant nanobots. Upon contact with your stomach acid they activate, building a 1cm one-way-portal which slowly extrudes NutraGoo™ over the course of the next 18 hours. Warning: Do not eat more than 1 bite of PortalBread™ per day. PortalBread™ portals maintain an output of 1cm^3 per hour, and never violently exceed this speed of output. NutraGoo™ has no FDA approved side effects. If you experience bloating please discontinue use of PortalBread™. [Answer] The previous answers look at the energy available in foods we know about such as fats and protein. But what is *possible* in terms of chemical energy density? Since I'm leaving the kitchen, I’ll convert 2000 calories to 8.2 megajoules, so I can compare energy from other sources. Gasoline contains 120 MJ per gallon, so 30 per quart, 15 per pint, or 7.5 per *cup*. So you would need more than a teacup and less than a drink can; still more than one mouthful. But how high *can* chemical energy go? [This chart](https://en.wikipedia.org/wiki/Energy_density#Energy_densities_ignoring_external_components) shows that Beryllium and Boron top the chart at 125 and 138 MJ/L. So if you could use that (with air) for fuel then about 65 ml would do. That’s a bit more than 2 fluid ounces, which *is* one swollow. So it’s at least *possible* that some highly energetic chemical substance (plus oxygen added separately) could provide that much energy in the required volume. All we need is the ability to make use of it. Perhaps symbiotic bacteria provide for digestion by converting it to useful forms. I don’t like where this is going though. Creatures not adapted to it (e.g. like a cow’s stomach) can “refit” by cultivating needed bacteria in their intestines. However, they take up residence in the large intestine, which is downstream to where said bacteria can be digested and those nutrients absorbed. So a “two pass” process would be needed. After “harvesting” the converted product, you will need to carefully separate the edible culture from other toxic cultures, or perhaps cook it to kill all biological activity. [Answer] I'm going outside the box here, but what about a drug that pulls stored fat/calorie reserves from your body more efficiently? You are active and feel fine while using it, but after a while you look like an escapee from a death camp. Most of the nutrition is not in the food, and so the food energy density is no longer critical. If the food were high in calories with this drug mixed in, it would works for a while, until the user falls over and needs to recover for a few weeks/months. [Answer] Sounds like peanutbutter shortbread cookies. Fat, protein, carbs, tasty. I think the magic is in making it palatable, and making it keep. Also, MREs. 4000 calories, weighs < 1 lb. Also, the lore doesn't say they're nutritious, just that they'll keep you going. So all you really need is calories. [Answer] Protein toxicity is not a concern in healthy people, as you can read [here](https://en.wikipedia.org/wiki/Protein_toxicity). Furthermore, 50g of protein per day is nowhere near enough to cause toxicity in a renal-impaired individual unless they had less than ~20% function. The presence of other macronutrients is irrelevant to elimination of protein metabolites. A person can survive for a long time on a protein-only diet, not that I'd recommend it. Amino acids are regularly converted to glucose, resulting in ammonias and other wastes which are eliminated through urine or through the pores via sweat. The belief that a protein-heavy diet places harmful stress on the kidneys has been largely disproved by recent studies and the anecdotal evidence of millions of healthy athletes. Your best bet using nonmagical medieval tech is [Pemmican](https://en.wikipedia.org/wiki/Pemmican), though it would need modification from the traditional recipes to better provide certain minerals and vitamins. Bread would likely mold or grow stale rather quickly, whereas Pemmican will keep for literally decades if properly sealed. [Answer] I know this is way too late, but it is possible to have specific molecular structure of fat acids to be much more dense that the regular fat. Now add some handwaviumy perfection for that structure to be split in stomach and you are done. [Answer] It’s not about calories, it’s about how your food can sustain a person. According to [Energy in natural processes and human consumption](http://www.ocean.washington.edu/courses/envir215/energynumbers.pdf) there is roughly 3824 kilocalories in a pound of coal. Which should be definitely enough to sustain a person, but woe to the person who decides to live on a diet of coal. The caloric content is only a piece of a process which depends a great deal on the bodily chemistry of the individual and the bodily chemistry of the species (no Leopards on a diet of bamboo leaves, but Koalas seem fine). The exact mechanic of sustenance by food is still not discovered. There are also no foods known which have been observed to sustain “average” person on a single bite a day. There are allegations of people fasting for prolonged periods of time or living off minuscule amounts of food for even more prolonged periods of time, mainly attributed to exceptional attributes of such people. As far as writing fictional stories goes, you are better off letting yourself invent any superfood that you like. If you want some realistic examples, there are probably none available, but you might come up with realistic-sounding stuff. Taking as an example, [whey protein powder](https://www.caloriecount.com/calories-eas-100-percent-whey-protein-i84161) at 150 calories per 40 grams, you’ll need to have 533 grams of whey protein powder to satisfy your requirement. That’s quite a lot, even if you are successful at compressing it into a small chunk. Maybe if you churned a pile of maggots, dissolved the mush and precipitated the protein, cleaning it thoroughly, you could get more energy-dense matter, then possibly compact it into small form-factor, maintaining its solubility or brittleness so it would be easy to consume, you could get into one-bite volume. Ideally, you will be after a foodstuff which does not result in waste production when put through the digestive system, i.e. is consumed completely and utterly. [Answer] My interpretation is that lembas 'satisfies a man's needs' as in it stops you from getting hungry for the day. One bite a day will keep you going for the day, but it won't be healthy for you at all. It won't be the main source of sustenance, the main source for sustenance would be the occassional wild meat they manage to catch every few days. As a person who fasts frequently (albeit for 12-15 hours max a day), the main problem isn't food, its water. Without drinking water for a few hours I already feel headaches and sleepiness. Lack of food would hit you only after a few days. So, to conclude, lembas is morale food. Not actually able to sustain you, but delicious enough to *taste* like it does. The company were just that sturdy. [Answer] The Lembas bread is based off of Pemmican, guys. Probably going to be the closest thing you can get. Which is actually pretty damn close lol. And yes, I do realize i revived a dead thread lol. ]
[Question] [ As in the title. We have the modern [periodic table](https://en.wikipedia.org/wiki/Periodic_table): [![periodic table](https://i.stack.imgur.com/yikLY.jpg)](https://i.stack.imgur.com/yikLY.jpg) In a potential near (or far) future setting humanity discovers a new element which serves as the basis for a cleaner, higher energy density fuel than anything we have today. How this element is found is irrelevant, I don't care if it came from a comet smashing into earth or was found on an exploratory space mission to some other place. 1. Are there potential gaps in the periodic table where such an element could exist? 2. Where on the periodic table would such an element land to be the *best* fuel source? Criteria for "best" * Higher energy density than Nuclear * Cleaner than all fossil fuel types * Preferably renewable. [Answer] ## No As we currently understand [physical chemistry](https://en.wikipedia.org/wiki/Physical_chemistry), all possible [elements](https://en.wikipedia.org/wiki/Chemical_element) are known below whatever the state of the art number is now ([Oganesson - Element 118](https://en.wikipedia.org/wiki/Oganesson)). The [atomic number](https://en.wikipedia.org/wiki/Atomic_number) of an element (the number that determines which element it is) can only be an integer. It is, after all, the number of protons contained in the [nucleus](https://simple.wikipedia.org/wiki/Atomic_nucleus). Just like there are no unknown integers between 1 & 118, there are no unknown elements in this range. [Chemical reactions](https://en.wikipedia.org/wiki/Chemical_reaction) occur by complicated interactions between [electron spin](https://en.wikipedia.org/wiki/Spin_(physics)), electrons filling (or not) [orbitals (valence electrons)](https://en.wikipedia.org/wiki/Covalent_bond), and [the charge of the atom (ionic bonds)](https://en.wikipedia.org/wiki/Ionic_bonding). All of this is due to the quantity of [electrons](https://en.wikipedia.org/wiki/Electron) (strongly influenced by the number of [protons](https://en.wikipedia.org/wiki/Proton) through the [electromagnetic force](https://en.wikipedia.org/wiki/Electromagnetism)) and how they fill the electron orbitals. So if you have a nucleus with no protons, it isn't "[element zero](http://masseffect.wikia.com/wiki/Element_Zero)," it is a [neutron](https://en.wikipedia.org/wiki/Neutron). Since neutrons have no charge, they do not bind any electrons. If a nucleus has no electrons, then it cannot interact chemically with anything. ### Magic Stable Island However, there's a current hypothesis called [Stable Island](https://en.wikipedia.org/wiki/Island_of_stability). It posits that certain, as yet to be discovered, elemental [isotopes](https://en.wikipedia.org/wiki/Isotope) will exhibit more stability than the elements around them in the periodic table. Some theoretical calculations show that some element's isotopes in the magic "stable island" could have half lives as high as $10^9$ (a billion) years. More recent calculations indicate they would possess much shorter half-lives on the order of hours or days. Since no isotope of any elements supposed to be in the magic island have ever been observed, scientific consensus is leaning strongly towards the lower estimates. The Stable Island is circled in the graphic. It looks like the center of the island is around atomic number of 112 and nucleon number of 276 & 278 (Copernicium - Cm). There is a second island of less stable nuclei at around Atomic Number 125 (nucleon number 294+). We've created some isotopes of Element 112, but its half-life is so short, we do not know its bulk properties. We haven't created any isotopes of Element 125: [![Stable Island](https://i.stack.imgur.com/nRyLf.png)](https://i.stack.imgur.com/nRyLf.png) **Vertical axis** is **Atomic Number** (number of $p$) and starts at 81 (Thallium). Each square represents an integer. **Horizontal axis** is **Nucleon Number** (number of $p$ + $n$) and starts at around 205. Each square represents an integer. Outlined boxes represent element isotopes already discovered or created. Dashed black line shows the "optimal" $\frac{p}{n}$ ratio for a stable element isotope. ### Finding an Unknown Element **I really like the idea of finding new elements**, so let's assume that: 1. The Stable Island exists 2. There are undiscovered isotopes in one or more of these Stable Islands 3. Some isotopes in the island have a half-life above $10^8$ years 4. Supernovas make these elements Plutonium (244Pu) has a half-life around $8 \cdot 10^7$ years. If we make some of it in a reactor, then for human purposes it sticks around forever. However, we have only once found any naturally occurring [244Pu (Do transuranic elements such as plutonium ever occur naturally?)](https://www.scientificamerican.com/article/do-transuranic-elements-s/). Just like Plutonium, a high-Z element with a half-life of $10^7$ - $10^8$ years would seem very stable to humans and exist for perhaps billions of years. All materials native to the solar system were create about 4.6 billions years ago in a supernova that cause the collapse of the dust cloud that formed our solar system. Since then radioactive elements have been decaying, so our proposed isotope would be short-lived enough that we should find very little or none of it in the materials native to our Solar System. Interestingly, the Sun is sitting in a galactic feature called [The Local Bubble](https://en.wikipedia.org/wiki/Local_Bubble). A series of supernovae which occurred from 10-50 million years ago blew the interstellar gases out of this region making the density of intergalactic gas in this region particularly low. More importantly, the timing and location of these supernovae mean it is conceivable that a chunk of material from one of them could have made the trip to our solar system over the last 30-50 million years. Since these supernovae occurred only $10^7$ years ago, our proposed radioactive isotope should still have a very high percent of the original undecayed isotope remaining. So imagine that humanity sees a body heading through the Solar System on a [hyperbolic trajectory](https://en.wikipedia.org/wiki/Hyperbolic_trajectory). This means that the body originated outside of our solar system and it will sail right through the Solar System unless we divert it. We would have to intercept and deflect it to pass near one of the gas giants to impart enough of a momentum change to capture it. Only one of these planets could deflect it enough to keep it in our Solar System. After deflection, we could find it is coated with a heavy elements (platinum group metals, uranium, plutonium, gold, and other materials that are rare on Earth). ### What to use it for Even if it burns more energetically with Oxygen than any other known chemical reaction (though physical chemistry suggests 118 is a Noble Gas, 112 will be close to a Noble Metal, and 125 will be a Rare Earth metal - so realistically you should expect any of these to react weakly or not at all with Oxygen), would humanity actually use it as a chemical fuel? **Certainly not.** It cannot be found on Earth, making it more valuable than any Terrestrial material you can think of (more valuable than Gold, Platinum, or even the most precious gemstones). If you were going to "burn" it, you wouldn't use the paltry energy release of chemical reactions (after all, how many people do you know who burn diamonds for heat?). Instead you'd go for the 1,000,000 $\times$ energy release of nuclear power. Even so (and regardless of your "no nuclear" caveat), I suspect the material would be way too valuable to "burn" in fission reactors. With a $10^8$ish year half-life the only way we would get more would be if another such body flew through the Solar System. Don't expect it to be any sort of renewable energy supply. (If you wanted an SF analogy of the depletion of the Earth's fossil fuels, this might make for an interesting story though) It would be used mostly for research - trying to discover just what the material could do. Or for the super wealthy, perhaps making some souvenir trinkets to wear (the material would be radioactive but not so radioactive as to be dangerous). ***Edit 2/29/2016:*** So I was thinking about this and thought, hey what if we had a moderately large metallic asteroid on hyperbolic course through our solar system. We sent a probe to it and found it was chock full of elements from the stable island. If we could deflect its course, we'd have a huge quantity of the stuff available for all sorts of things (fission reactors, research, special material properties, etc.). These materials would still not be used for their chemical reactions, the energy released would not be worth the energy investment to get the materials. It might be used for fission if it was a superior fission fuel (it would release more energy than the fission fuels we already use). Perhaps "burning" it would result in fission "ash" that were especially valuable elements (like platinum group metals), and released far fewer neutrons during the reaction. But that violates your no nuclear power criteria. Regardless, this scenario also breaks your renewables scenario. ### Other ways to get there There are at least two other ways to get what you want. **Fusion** Some form of fusion, preferably cheap and low energy (aka "cold fusion") would serve nicely. There's no plausible and economic mechanism for this to work at the moment but it would not be a complete violation of physical laws to assume some way of doing it was discovered. **Metastable Helium** A Helium atom has 2 electrons. The lowest energy orbital is the "1S" orbital. The "1S" orbital can hold up to 2 electrons. However, those two electrons must possess different values of "spin" (one "up" and one "down"). If you instead give the Helium two electrons with the same spin value (e.g. two with the "up" spin), then one will sit in the "1s" orbital but its presence prevents the second electron from also falling into the "1s" orbital. Instead it sits in the "2s" orbital. This is called **Metastable Helium.** [Metastable Helium](http://web.archive.org/web/20040804131304/http://www.islandone.org/APC/Chemical/07.html) could conceivably provide energies far higher than any chemical reaction and give specific impulses of up to 10x that of $2\text{H}\_{2\text{(L)}} + \text{O}\_{2\text{(L)}} \rightarrow 2\text{H}\_2\text{O}$. Since this is a "Real Thing", you wouldn't be violating the laws of physics to include it in your world. Metastable Helium has a half-life of about 2.3 hours but it can be catalyzed to decay ("burn") faster. The two main drawbacks of Metastable Helium are: 1. It is not a fuel, it is an energy storage mechanism (you still need power plants to make your energy). 2. Metastable Helium is, well, metastable. It has a tendency to spontaneously release its energy. Helium switching from metastable to stable tends to catalyze surrounding Metastable Helium to do the same thing. If you have a large fuel tank, the large quantity and the high energy density of the substance tends to lead to an "Earth shattering ***Ka-Boom***" There's a variant of Metastable Helium that reduces of some of its problems (e.g. making it more stable and giving it a longer half-life). This is called diatomic metastable Helium. You bond a metastable Helium to a stable Helium then chill it until it forms a solid. The resulting material has a half-life measured in years but it releases its energy when exposed to heat. Unfortunately, this halves the energy density of Metastable Helium - but that's still much better than typical chemical reactions. **[Nuclear Isomers](https://en.wikipedia.org/wiki/Hafnium_controversy)** Another possibility is a nuclear isomer. Imagine a small but very elastic balloon with a wide mouth. Fill this balloon with 72 black ping pong balls (protons - $p$) and 102 white ping pong balls (neutrons - $n$) representative of the nucleus of Hafnium (Hf). Both $p$ and $n$ are nucleons. Each ping pong ball has a Mexican jumping bean in it. Shake your balloon until you get the minimum possible surface area - this is known as your minimum or ground energy state. Now carefully pull one nucleon out of its ground state and move it to the other side of the balloon so it sticks out. This is a **nuclear isomer** and represents the "excited state" of the nucleus. If you just let the configuration sit for a while, the random energy supplied by the Mexican jumping beans will eventually cause the ping pong balls to suddenly shift back into their ground state. This will release a sound ("voomp!"). The balloon represents a nucleus. The ping pong balls represents the nucleons. The sound is the gamma ray ($\gamma$) released when the nuclear isomer releases its energy. If you bang the balloon sufficiently hard, the nucleus will reconfigure to the ground state too. This is the what scientists are trying to prove in the lab. While Metastable Helium uses excited electron states to store energy, nuclear isomers store energy in excited nucleons. Just as nuclear reactions are $10^6 \times$ more powerful than chemical ones, excited nucleons can store enormously more energy than electrons (on the order of $5 \cdot 10^5 \times$ more than most chemical reactions). Similar to how the range of half-lives for radioactive elements range from picoseconds to more than tens of billions of years, the same is true for nuclear isomers. It is thought one isomer has a half-life of around $10^{15}$ years - it has never been observed to decay and has no practical use. Others have half-lives so short they are of no practical use either because all atoms in the sample appear to spontaneously decay. However, Hafnium has a nuclear isomer with a very convenient half-life of 31 years and might be useful. There are a few problems with nuclear isomers. These include an inability to trigger the release of the energy (\*\*more on this below). Energy is released from Hafnium as gamma rays (which requires shielding). As with Metastable Helium, nuclear isomers are not a fuel but are an energy storage mechanism. They are only renewable in the same way that batteries (and Metastable Helium) are renewable - they can be recharged and reused. There has been some controversial research indicating that a method of stimulating the release of energy from nuclear isomers has been found. So far though, the amount of energy required to stimulate them is more than the energy they can release. Despite all those issues, nuclear isomers are theoretically possible energy storage mechanism and they could become a component of an awesome energy storage infrastructure. You would charge them up and then use them like batteries whose power slowly wound down. ### Energy Densities You won't find any non-nuclear energy source with energy densities greater than those of nuclear. It has to do with the type of forces involved (Nuclear Strong and Weak versus Electromagnetism) and is fundamental to the nature of the Universe. Many people don't have an innate understanding of the relative magnitudes of the energy released between chemical and nuclear power. So let's use distance as representative of energy. If 1 cm correlates to the energy released by the most powerful chemical reactions, then 16 kilometers is the energy released by nuclear fission. Fusion is 100+$\times$ more powerful (represented by a distance 1,600 kilometers). Generating power using chemical energy is just not very effective compared to nuclear. This is the relative [energy densities](https://en.wikipedia.org/wiki/Energy_density#Energy_densities_of_common_energy_storage_materials) of several materials: * Antimatter > $12 \times$ Fusion (Wiki value of $150 \times$) * Fusion > $4 \times$ Fission (Wiki value of $100 \times$) * Fission > $10^6 \times$ chemical (Wiki value of $1.6 \cdot 10^6 \times$) * Nuclear Isomer > $5 \cdot 10^5 \times$ chemical * Metastable Helium > $10-100 \times$ most other chemical (Wiki value $10 \times$) * Diatomic Metastable Helium > $5-50 \times$ most other chemical (Wiki value $5 \times$) * Most chemical fuels > $100 \times$ most renewables (direct comparison is difficult because renewable fuels are often "free" but their infrastructure is huge and costly) Incidentally, you get the most energetic chemical reactions between elements by combining elements from the upper right of the periodic table (oxidizers like Fluorine/Oxygen) with those on the lower left (reducers / alkali metals). An as yet not created alkali metal [Ununennium - Element 119](https://en.wikipedia.org/wiki/Ununennium) would satisfy your requirements. However, this element is not expected to have a half-life greater than microseconds and wouldn't survive a trip from the nearest supernova (the stellar event that creates such elements) to the Solar System. You can create molecules with more combustion energy by many mechanisms. Most of these extremely powerful explosives are not stable and therefore not safe to use in most cases. Others (e.g. [Octanitrocubane aka Cubane](https://en.wikipedia.org/wiki/Octanitrocubane)), are so difficult to create that they are too expensive to manufacture in quantity. > > Octanitrocubane (molecular formula: C8(NO2)8) is a high explosive > that, like TNT, is shock-insensitive (not readily detonated by shock). > > > ... > > > Octanitrocubane is thought to have 20–25% greater performance than > HMX (octogen). > > > But ultimately chemical reaction energies are limited by the energies available by chemical bond strengths. ### Renewables Renewables at least as commonly conceived (e.g. wind & solar) possess *extremely low* energy densities. Consider a wind farm with 1000 of the large 1 MW wind turbines. It would cover many square miles and generate 1/5 or less of the energy produced by a single mid-sized 1 GW coal burning or nuclear plant which occupies a just a couple of acres of land (actual power generated and not installed theoretical capacity). If you need energy density, then you need nuclear. If you want renewables, then you have to live with extremely poor energy densities. If you want both, then you need something like the Metastable Helium (see above) to store the energy produced by your low energy density power plant in a form that has high energy density (but you still have to live with the huge, low energy density wind farm). Although it is currently popular to extol the virtues of "renewables", ultimately renewables come from sunlight and sunlight comes from the Sun which is a giant nuclear power plant. Why deal with all the middlemen (intervening processes) each of which has fairly steep efficiency loss. Why not work directly with the nuclear power? ### How might this work? Using the diatomic metastable Helium example... Suppose scientists were examining cometary materials (how they were collected isn't important) and discovered one such compound contained metastable helium in some form that was much more stable than any we've discovered so far. Just knowing that a material like that existed and having some examples would lead to a huge new area of research. Eventually, everything might run on the new energy storage media using the metastable helium compound as the battery and huge renewables spread across the planet (or the Moon) to power up those batteries. We would not depend upon mining the materials from heavenly sources. As an alternative if it is important in your story that we had to mine the fuel source, then you could always turn to mining the Moon and other astronomical bodies for 3He. That requires you to use nuclear though. On the plus side, 3He throws off significantly fewer neutrons than most other fusion reactions. [Answer] Short answer: No. Elements are identified by their atomic number, i.e. the number of protons in the nucleus. When Mendeleev invented the periodic table, there were a number of holes. For example, there was no known element between Calcium, atomic number 20, and Titanium, number 22. Mendeleev therefore proposed the existence of new, previously unknown elements. He predicted properties of these elements based on where they would fit in his periodic table. When these elements were found and indeed did have the properties he predicted, this was strong evidence that the theory behind his periodic table was correct. (Note: Mendeleev built his table using atomic weights rather than atomic numbers, so his methods were not quite as rigorous as we have today. But that's a side point.) Today we have identified elements for every possible atomic number from 1 (Hydrogen) to 118 (tentatively named ununoctium). That is, we know elements 1, 2, 3, 4, 5, 6, etc, every possible integer up to 118. So any unknown elements must have atomic numbers higher than 118. All known elements with atomic numbers 84 or higher (84=Polonium) are radioactive and unstable. As Jim2B mentions, some physicists theorize that there may be stable elements with higher atomic numbers, but no such elements have ever been found in nature or synthesized in the lab, so at this point it's all theory. [Answer] People have already covered the parts of the question about the periodic table so I'd like to just talk about one of the side-conditions for a moment. The two desired properties of renewable and higher energy density than nuclear are, essentially, mutually contradictory. Something being renewable means that the substance can, essentially, come into existence spontaneously. In turn, that means that it can't require huge amounts of energy to construct because, whatever spontaneous process creates the substance from other sources would have to somehow put that energy in. In particular, it would have to concentrate that energy to the energy density of whatever stuff it's making. That very much limits the energy density of renewable resources. Any spontaneous process that tried to pack so much energy into a small place would probably find it easier to light itself on fire than to produce unobtainium. Not least because there are so many different ways of catching fire, but only a couple of ways of synthesizing unobtanium. [Answer] You've answered your own question by posting an image of the Periodic Table - clearly there are no *gaps* between 1 and 118. However, since this is **WB** and not **Physics**, let's speculate. The nucleus is usually depicted as a bunch of grapes, forming a spherical structure, since that is the lowest energy state. But is it... Nuclei are bound together by the *Strong Force*. This is very short range - essentially binding nucleons to their nearest neighbours. Fighting against the *Strong Force* is the electrostatic repulsion of the protons, which is long range. Any one proton feels repelled by all the others in the nucleus. As the nucleus grows, the repulsive force becomes greater while the *Strong Force* doesn't really change. Adding neutral neutrons helps because this pushes the protons further apart, thus weakening the electrostatic force. This is why the proton-neutron mix starts off about equal and becomes increasingly neutron-rich as we go up. By the time we get to a few hundred nucleons, it is getting difficult to keep the thing together and we get radioactive isotopes that keep falling apart. However, what if there is a region of stability in the very large atomic number range? Maybe when we get to, say, 1000 nuclei, structures can form that lead to it being stable. For example, you could have an outer shell of alternating protons and neutrons (like the pattern on a football) with a central core of neutrons. That would keep the protons well apart but allow you to have a massive nucleus. Its chemical properties would be weird - a giant nucleus would play havoc with the electron orbital radii. It would be very dense - maybe two or three orders of magnitude denser than existing elements. If you perturbed the proton-neutron lattice, it would decay into a spray of lighter elements and release rather a lot of energy, I would imagine. Such a thing would be unlikely to form naturally since nuclei are usually made by squishing together lighter nuclei. However, you might be able to *engineer* such a nucleus: make a 2D $p-n$ lattice, then wrap it round a blob of neutronium. Simples! [Answer] Lots of good answers, but here's my $0.02 (before tax). First, there's no room to throw new elements into the mix unless you can find some interesting high-mass element that breaks all the known rules. No gaps to fill except with some odd isotopes and such. That said, let's look at your three conditions in reverse order: **#3: Renewable** This is going to depend on your source, I guess. In general this means either that the fuel and/or any precursor materials are not a static resource (no mining it from asteroids or similar). Fossil fuels are not renewable, plant-derived alcohols and bio-diesels are. This one might be fairly simple to resolve, might not. **#2: Clean** Not quite as simple as it sounds. If you just mean that it produces a minimum of environmental impact when used as a fuel source, without regard to the environmental impact of its manufacture, then we can maybe throw a lot of interesting things into the mix. Both sides of that are problems for nuclear energy since both the refining and use of nuclear materials produces waste products that are likely to be a problem for millennia. **#1: Better than Nuclear** The reason I reversed the order, this is both the hardest criteria to satisfy and the most direct influence on the possible answers. No matter what sort of obscure atomic isotopes or fictional element you come up with, chemical reactions simply do not release the sort of energy that nuclear ones do. Period. Chemical bonds are orders of magnitude less strong than nuclear ones, and that's never going to change no matter what material you're reacting. Which to my mind leaves one actually real material: anti-matter. Specifically, Antihydrogen composed of a nucleus of 1 antiproton with a single positron. This was first synthesized (in ultra-tiny proportions, of course) at CERN back in the 90s and is still being studied. If the predictions are true it will act exactly like normal Hydrogen and form the anti-matter equivalent of H2 gas. Take 1 part Hydrogen and one part Antihydrogen, mix in an appropriate reactor - taking care to never let your antimatter come in contact with 'normal' matter - and the resultant energy release (gamma rays from the electron/positron reaction plus various pions, muons, neutrinos, positrons and electrons from the proton/antiproton) is as close as you can currently get to complete liberation of energy from mass. Apart from the neutrinos escaping pretty much any currently available containment the result is pretty close to the highest density fuel it is possible to make, almost pure E=MC2. By fuel mass a Matter/Antimatter power plant should produce around 2 billion times as much power as a diesel engine. If you wanted to power a land vehicle with it (assuming you can build a compact reactor) a gram of Anti-Hydrogen will last for a freaking long time. From the 'clean' perspective, M/AM reactions have fairly safe byproducts if you can capture the gamma rays and so on. There's no waste gasses from combustion, no water, etc. If you could just use positrons all you'd get is a whole bunch of gamma, but storing them is even harder when you don't have an antiproton for them to latch to. Effectively though the only real emissions from the reactor will be neutrinos, which aren't all that interested in reacting with anything. At high enough densities there could be some odd effects, maybe the occasional transmutation or unplanned ionization in surrounding matter... nothing big. Antimatter can be synthesized in small quantities at the moment by using stupendous amounts of power, which is a bit of a drawback. But if you can solve the synthesis problem and have access to sufficient energy from other sources then you could perhaps produce a steady supply. That covers renewable. The problem of course is that you have almost zero chance of avoiding the inevitable uncontained M/AM reaction and wiping your species off the face of the planet. Maybe only use this stuff in space where an explosion is less likely to tear holes in the planetary crust. All of the above relies on a very high technology level - think Space Opera - and before all of the kinks are worked out it might be possible to create a device which liberates energy directly from matter. Personally I'd be happier to see a matter-to-energy converter than M/AM reactors, but both are way out of our reach right now. [Answer] Suppose 128ium were a catalyst for a low temperature fusion reaction - like common isotope A fuses with common isotope B on the surface of a 128ium nucleus to result in unstable isotope C which decays rapidly by beta decay into stable byproduct D, generating lots of heat and no dangerous by-products. You'll have to comb through a nuclear decay chart to find a friendly reaction, or make one up that's off the chart but plausible. [Answer] *Yes, perhaps* Look into multipositronic systems. <http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.83.5471> The short version is that you can have bind positrons (i.e. anti-electrons) to negative ions to create new, fancy atoms. Thus in between the elements of the periodic table you can have new 'elements'. To my knowledge not much about the properties of such things are known, but that's where I would go for mystery matter. [Answer] [![899 number line](https://i.stack.imgur.com/raqIC.png)](https://i.stack.imgur.com/raqIC.png) [This xkcd cartoon](http://www.explainxkcd.com/wiki/index.php/899:_Number_Line) sucked me in to a few hours wasted time with the note you see between 3 and 4, "*Gird— Accepted as Canon by orthodox mathematicians*". On the *explains* page I linked you see links to related values: Bleem, Derf, Bleen, SCP-033 (which nearly lost me my tablet), and Sorf. You can start there and find online stories (and even a short film now) for *The Strangest Number*, etc. So having *bleem* jelly beans is a silly trick. *Why* do the overloards not want us to notice this integer? Maybe having *bleem* **protons** in an atom is far more of a serious matter. If you have an extra *number* you have overlooked, then you will have a corresponding element, and some isotopes of a few other elements. [Answer] > > Are there potential gaps in the periodic table where such an element could exist? > > > As everyone else has said: **No.** While you might have elements beyond 118 (and Jim2B has terrifically addressed the possibility of some of them being stable), there are clearly no existing gaps in the periodic table, and nothing will change that. > > Where on the periodic table would such an element land to be the best fuel source? > > > First, we have to discuss what it means to be an *element*, and what it means to be a *fuel*. An atom of a given *element* can be thought of as a *nucleus* surrounded by a cloud of *electrons*. To act as a *fuel*, these atoms must react in such a way that they produce energy. When atoms react, they can do so in one of two ways. First, they might interact superficially, through the surrounding cloud of *electrons*, creating and breaking *chemical bonds* with other atoms in a process known as ***chemical reactions***. Secondly, they could react at a deeper level, fusing or breaking apart their *nuclei* -- a process known as (wait for it...) ***nuclear reactions***. Thus, by the very definition of an element, you're automatically limited to either weaker chemical reactions, or more energetic nuclear reactions. But you've *a priori* ruled out nuclear reactions as not powerful enough, so it's not clear ***what kind of reaction*** you're looking for. There really isn't much of a third option here -- either you involve the nucleus in the reaction or you don't (thereby forfeiting their larger amount of energy). I'll give two options, both of which technically break your rules. ## Nuclear Redux You don't explain why you don't want nuclear, except that you want a higher energy density. As mentioned, nuclear reactions *are* the higher density reactions. However, not all "nuclear" is equal. Is it OK if it's nuclear power, but with a higher power density than current nuclear plants? The main categories of nuclear power are fission and fusion. But even within these categories, there is a huge variety of designs with staggering differences between them. In fact, the amount of energy you can get out of a given amount of fuel is largely determined by the reactor design, not just the fuel. For example, most of the nuclear reactors in use today are "Generation II" reactors, designed and built between the 60's and the 90's. A few of the newer ones are Generation III, which are incremental improvements on Gen II designs, but are still based on solid fuel rods and pressurized water cooling. However, there are a number of [Generation IV](https://en.wikipedia.org/wiki/Generation_IV_reactor) reactor designs -- for example, various molten salt reactors (MSRs) -- that look as if they can deliver "***100-300 times*** more energy yield from the same amount of nuclear fuel". Where current Gen II or III designs only extract a small portion of a fuel's energy and leave behind a large amount of waste, these newer designs are capable of squeezing out the majority of a fuel's energy, leaving behind very little waste that is relatively short-lived. For your purposes, does this count as being more power dense than nuclear? The best fuels for fission end up being as massive as possible and radioactive, yet stable enough to not quickly decay into something else. The elements that best fit that bill are things like Uranium and Thorium. With MSRs especially, there is a debate about whether to stick with Uranium fuel, or switch to Thorium, which apparently is more power dense than uranium, and arguably more common. While not quite renewable, both elements are in abundance on our planet, and would essentially last indefinitely (the ocean is saturated with Uranium that enters it from rivers, and Thorium is an extremely common byproduct of certain types of mining that currently gets thrown away; it's also common on the Moon). Uranium and Thorium are the only significantly radioactive elements that exist on our planet in large amounts. And this is all before we even start to consider fusion. In fusion, since you're trying to make the nuclei go fast enough to bump into each other without being deflected, the best fuel is lightweight -- hence the desire to use Hydrogen or Helium (atomic numbers 1 and 2). Some fusion reactors use an isotope of Helium known as Helium-3. ## Antimatter This is not an element, but a different type of matter, with opposite electric charge from regular matter. When matter and antimatter meet, they annihilate each other, and produce the maximum possible amount of energy for a given amount of mass. This is your absolute limit on the amount of energy you can extract from matter. Technically, this is also a form of nuclear reaction, since you're annihilating the nucleus. The problem is that antimatter is not known to occur in nature, and is very difficult to make, so you end up losing energy in the process. This is where I'm going to stray a bit from known science and speculate for the purpose of fiction. I can think of a few possible sources where you might find antimatter. **Interstellar Medium** This is probably false, but there's a small chance that you might happen to run into trace amounts of antimatter in the vacuum of deep space, much like interstellar hydrogen. This could conceivably be scooped up and harvested with some sort of Bussard Ramjet. I assume this is how the *USS Enterprise* gets at least some of its antimatter. **Black Holes** While black holes are usually thought of as things from which nothing can escape, Stephen Hawking actually argued that they evaporate, emitting so-called Hawking radiation in the process. This can be thought of as a particle/anti-particle pair forming from the vacuum near an event horizon, and then one member getting sucked into the black hole, while the other is freed. You might think about trying to manipulate with electromagnetic fields which member of the pair is devoured and which is emitted, it's probably just easier to harvest the resulting Hawking radiation directly (again, speaking in a purely speculative manner). Or, as long as you've got a black hole, you could go for some of the other options listed here: <https://physics.stackexchange.com/questions/20813/how-would-a-black-hole-power-plant-work> **Magnetic Fields** Taking a step back from the exotic physics of black holes, it turns out that a similar particle/antiparticle process occurs when cosmic radiation strikes a planetary atmosphere. And if there's a magnetic field present, this can trap the antiparticles. According to [this page](http://www.centauri-dreams.org/?p=1567), it's belived that there could be on the order of several hundred micrograms of antimatter stored in Saturn's radiation belts, and a good amount around Earth as well. How you go about extracting it is another question entirely. The good thing is that it will be renewed by more cosmic radiation. [Answer] No , but perhaps an isotope of a preexisting element can discovered Due to the nature of the periodic stable , the can not be any gaps in it, however , some super fuel isotope can be discovered like deuterium or uranium 235 [Answer] ### Why an element? Are you sure that you want your fuel to be a new *element*? As others have noted, we've pretty well covered the element space. New elements are just increasingly unstable clumps of protons and neutrons (with electrons circling them) that only exist in rare situations. We already know ways to make use of higher density fuels. For example, nuclear fission is so energy dense that the contaminants in coal would provide more energy if used as uranium than if the coal were burned. We don't use that because it's expensive. Another, even higher density fuel, is anti-matter. We don't use that as a fuel now because we don't have a source for it and don't really have the equipment to manage it if we did. It's not even as far along in the development process as fusion. So if the people in your world discover a plentiful source of anti-matter and figure out a way to harvest it, that would fill much the same space as a new element. And it could operate entirely in keeping with what we know about the universe. What about lower level particles? Why restrict yourself to just atoms? You could instead be talking about something made from quarks other than the more standard proton, neutron, electron, neutrino, and their anti-particles. This wouldn't fit into the periodic table, but it would act more like a new element. Another possibility would be an alternate version of energy. Currently we can store energy as potential energy, kinetic energy, or electromagnetic energy (photons). What if you discovered a more manageable version of a photon? Easier to store as energy? Or figure out a way to use the basic underpinnings of gravity to store energy. We don't know how gravity is transmitted. We speculate a lot. Perhaps one branch of speculation is suitable for your purposes. Perhaps the secret is gravitons. Or something else. If that sounds interesting, I'd suggest a new question where someone more knowledgeable than I could give more concrete suggestions. I think that if you let go of the periodic table, it will be easier to accomplish your real goal. [Answer] (1) There is no logical gap in the periodic table in which you could insert a new mystery element for use as a fuel. (2) Even so, do not rule out solutions with ions and molecules. Neither type is an *element.* Nuclear fuel is good for a number of purposes, but it decays over time. Also, the *best* energy source depends on the use it is to be put. I speculate that what you really want is a fuel that plausibly can remaining in a high potential state while it travels light years. For a science fictions story, it might be helpful if the fuel can be renewed, or recharged, in orbit around a distant sun. Consider a device that utilizes ions, molecules, and magnetohydrodymanics and can be recharged by solar power. You can call the device one of the spacecraft's fuels, but disclose to your readers that it is more than just *elements.* [Answer] Nyes. Or Yeno. Or perhaps mayes, or nobe. Or any other variation of yes-no-maybe. As many posters here have expertly said, there are no gaps in the periodic table. The number of protons has to be an integer number. Except, why an integer number? Why not one and a half protons? We now know that protons are not indivisible. They are made up of even smaller particles. So an atom that is made up of an unusual proton? One that is heavier or lighter than a normal proton? Perhaps it only has two quarks, or perhaps six? There is no reason to believe that it could not be an element distinct from one with normal (three quark) protons. And since it might just have a more or less positive charge than a traditional proton, the number of electrons needed to balance the charge would produce an interesting situation. How would you fit such an element into the periodic table, except to say that it filled a gap? Not an isotope, but an element with the same number of protons, only the protons were different? Call it, say, element 91(a) and 91(b), or 91 and 91.5? I could not even begin to imagine the energies that could be available under such a circumstance, and how they could be released. Perhaps in some nuclear conversion back to a traditional proton? But that is the beauty of fiction. You need not explain any more than is necessary for the plot. "Feasible" is good enough. [Answer] There are, evidently, no gaps in the periodic table due to the integer nature of elements and the plethora of other reasons from other answers. However, it doesn't look like anyone has mentioned **neutronium**, which can give you some wiggle room at the head of the periodic table rather than the end. ## Neutronium Certainly a hypothetical substance, it's composed entirely of neutrons. There are [some nuclear models](https://arxiv.org/abs/nucl-th/0301020) that permit this, and others that [explicitly exclude it](http://onlinelibrary.wiley.com/doi/10.1002/ange.19260392303/pdf). In your universe, it may be these first models that are correct and allow neutronium as an element. Given how little we know about it, you'll have more or less free reign about what exactly its properties are and how it can be used as a fuel source. [Answer] Although the question of whether there are gaps in the chemical table has been answered thoroughly here, and there has been some discussion of alternate fuel sources *besides* chemical combustion, I would like to expound upon that a bit. The reason why is because, although there are no gaps in the periodic table, there is plenty of room for new stuff in [the standard model](https://en.wikipedia.org/wiki/Standard_Model#Particle_content), which is the domain of [high-energy physics](https://en.wikipedia.org/wiki/CERN), and high energy is precisely what you seem to be interested in. Better, since so little is known on the fringes of the model, there is an incredible amount of room to make stuff up. # All energy production, simplified ## (Bear with me) To simplify the general problem of "energy production", it is helpful to recall that [energy can be neither created nor destroyed](https://en.wikipedia.org/wiki/Conservation_of_energy). What this means is that energy isn't actually produced.... it was there all along. The mechanism by which we harness said energy is by moving a system from [one stable state at a relatively high energy to another stable state with lower energy](http://kentchemistry.com/links/Kinetics/PEDiagrams.htm). Often, by use of [some clever mechanism](https://en.wikipedia.org/wiki/Engine), the mover can harness the difference. For example, when one burns coal, the reaction `C + O_2 -> CO_2` occurs. It is a happy coincidence of our universe that, although having separate `C + O_2` is at a relatively high energy, and `CO_2` is at a lower energy, the state of matter "in between" those two situations is *even higher energy*. This prevents all of the `C` and the `O_2` from simply spontaneously collapsing into `CO_2`. In order to overcome this "barrier" of the even higher energy state, we have to input some amount of energy. However, one gets that energy back when the reaction finally settles at `CO_2`. **SO** to generalize the process of burning coal: Take a system at a high, but stable, energy state. Hope that that system has a lower, but not yet realized, energy state. Input energy to move the system from the higher to the lower energy state. Get your input energy back, plus some, by use of some energy-harnessing-device. Nuclear energy works just this way: Uranium is a high energy state. Krypton and Barium (the byproducts of Uranium fission) are lower energy. The state "in between" is *very* high energy. One inputs energy to the Uranium to overcome the "in between" state, ending up with Krypton and Barium (the low energy state) and a crapboat of heat energy that can power, for example, a steam engine. Hydroelectric energy works just this way: Water in a mountain is a high energy state. By releasing the floodgates on the dam, the water moves to a lower energy state in a valley. By use of a water wheel, we can harness the difference. etc etc etc. # What does this have to do with anything get to the point geez ## (Making up a new energy source) Modern physics is full of [weird fields](https://en.wikipedia.org/wiki/Higgs_boson#Higgs_field) that simply exist all around us, scientists have only [just begun](https://en.wikipedia.org/wiki/CERN#Scientific_achievements) to explore some of this stuff experimentally, and there are plenty of [speculative](https://en.wikipedia.org/wiki/Dark_energy) forms of we-know-not-what hypothesized to exist. This leaves lots of room for invention, since *all you need is a high-energy state, a means to move it into a lower-energy state, and a mechanism by which you harness the difference*. One can invent a new higher energy state for stuff, a new lower energy state for stuff, or both. So, what does this mean for worldbuilding? Some immediate consequences: 1) Going from "ordinary" stuff to "ordinary" stuff: Modern physics has a decent handle on the energy states of the stuff that we see and feel around us. This means that if your high-energy state *and* your low-energy state BOTH involve "ordinary stuff", then it will be **trivial to check your work**. For example, *regardless of the mechanism you use to harness the energy*, the "nuclear energy" reaction: `U -> Kr + Ba` produces a **fixed quantity** of energy that can be calculated, and is [independent](https://en.wikipedia.org/wiki/Conservation_of_energy) of any fancy new device you conceive. In other words, if your new energy-producing mechanism looks like: `Ordinary stuff -> Other ordinary stuff`, then you will obtain an "ordinary" amount of energy, because we know all about how ordinary stuff works. 2) Going from "exotic" stuff to "ordinary" stuff: For example, you might hypothesize that [dark matter](https://en.wikipedia.org/wiki/Dark_matter) is an incredibly high-energy state of matter, that there is some source of this stuff, that there exists some mechanism to transform dark matter into "ordinary" matter, and devise some device to harness the difference in energy. As a side effect, you would have a waste product of "ordinary" matter. You could generate basically infinite amounts of energy this way. 3) Going from "ordinary" stuff to "exotic" stuff: You might hypothesize that dark matter is an incredibly *low*-energy state of matter. However, since the starting "ordinary" matter energy-level is known, you can only harness so much energy this way. The upper bound is [`E=mc^2`](https://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence). However, `mc^2` is a whole heck of a lot of energy. OTOH, the concept of [negative energy](https://en.wikipedia.org/wiki/Negative_energy) might be able to overcome this limitation. 4) Going from "exotic" stuff to "exotic" stuff: The world is your oyster, but it might be difficult to distinguish your new energy source [from magic](https://en.wikipedia.org/wiki/Clarke%27s_three_laws). [Answer] **Yes** I'll keep my answer very short: <https://en.m.wikipedia.org/wiki/Exotic_matter> There are a lot of examples if you browse through the page, and there are a lot of unknowns regarding them. If you wave your hands really hard, you might be able to use one of these. Edit: they're not necessarily gaps in the periodic table. They're more like extensions to what we call everyday matter. They can't be placed on the periodic table as we know it. [Answer] Like JIm2B said, there really is no conventional, non-exotic matter you could shove into the periodic table without breaking physics, and unless you create an island of stability, the atoms decay too fast to use as actual fuel the way you seem to want. The point of this site isn't to let people tell you why your idea is impossible, it's to help you figure out how to make it work in your story. With that in mind, let's dive into some plausible (-sounding) ideas for naturally occurring sources of fuel that have not been discovered or created on earth as of now: * First, you could probably use [positronium](https://en.wikipedia.org/wiki/Positronium) for something smart-sounding. Positronium is made of one electron orbiting its anti-particle, and according to thirty seconds on Wikipedia, is extremely common but has not been synthesized *en masse* on earth. It is also very unstable, but can likely be stored with electric fields and (what else?) magnets. * Secondly, tachyonic matter (along with other exotic particles) is a possible component for the [Alcubierre drive](https://en.wikipedia.org/wiki/Alcubierre_drive). This works very well in terms of being “discovered”, as [tachyons](https://en.wikipedia.org/wiki/Tachyon) have not been proven to exist and have not been synthesized by humans. On the other hand, this is less fuel as it is structural components, but you could hand-wave this by saying that tachyons are naturally hard to contain or must be used up to provide negative energy density to the warp field. Finally, you couldn't have physical stockpiles of tachyons waiting around to be exploited; perhaps they are produced by certain kinds of quasar or black hole? Or you could simply use antihelium and helium as reactants for a antimatter drive, but that wouldn't necessitate discovering anything and, more importantly, not be much fun. ]
[Question] [ In a JRPG-like setting; Spells are chanted, mana is consumed, and spells can be learned through grimoires or spellbooks, how would it make sense that a spellbook teaches only one spell? If it is like cooking, like say, how to bake a cake. Why would it take a whole book to learn? How could I make sense out of this? [Answer] ### Each book teaches a way of thinking and living - not just a spell It's necessary because each spell requires a special way of thinking about the aspects it controls. If you want to use a certain spell from what is commonly called *Fire Magic*, you have to understand where you get the energy, what to do at what stage of the spell to not burn yourself, how to direct that energy towards your target, how to release the energy at the correct time, how to give the energy back to the endless energy around you and in yourself, etc. You have to understand how the energy interacts with other forms of energy, with your body, with your soul, with other lifeforms. You have to be aware of the consequences of losing control for even a second. You have to be aware of your responsibility. You have to understand that the Fire Magic is not something inborn. It is something you need to train. Very often and for a long time. The book teaches you not just words, phrases, intonations, rituals, gestures, materials needed, preparations, shortcuts, best usecases, worst usecases, as @Innovine pointed out the history of the spell and its most important users and authors with their most important accomplishments and failures, traditional usecases, experimental usecases, preferred tactics aforementioned individuals used or thought of and many more things that are directly necessary to cast a spell in battle - it teaches you how to live your life so that you have the right attitude to be able to cast that spell. Daily rituals. A certain way of thinking. Behaviour towards the energy that surrounds you and the lifeforms you meet on your way. **Magic is not just "take x energy and say *Fire*". Magic is a lifestyle. And each magical spell teaches a different lifestyle. So different that to truly understand it you need to read and understand a whole book about it.** Even if you know seemingly similar spells you have to understand a lot of different things for a new spell. Just because you know the *Fireball* doesn't make it easier to learn the *Fire Wall*. Maybe a bit, but there is not enough overlap to write a generic book about *The Basics of Fire Magic* with additional booklets about the *Fireball* and the *Fire Wall*. [Answer] Books of magic are magical, if not appropriately separated the spells have a tendency to interact in an uncontrolled manner. The more powerful the spell the worse it gets. While it's *relatively* safe to keep household spells all in one book, cooking, fire lighting and cleaning spells aren't particularly dangerous, maybe your broom will leave trails of sparks round the house or your dinner might be really clean, but if you start putting major summoning spells into one tome you never know what you're going to get. Enchanted leather bindings are critical for isolation, sometimes with metal plates inserted for the more lively spells. Scrolls are acceptable but must be [vellum](https://en.wikipedia.org/wiki/Vellum), not papyrus. Card or paper bindings are frankly dangerous. [Answer] # Spellbooks = Logarithm Tables In order to cast a spell, there are specific time- and location-dependant pieces of information you need to use that form part of the invocation. While you could compute these parameters by hand each time, it's far quicker and much more practical to look their values up in a book of tables. In real life, in the 1600-1900s, people used books of tables to calculate logarithms, trigonometric functions, random numbers, and many other things. For example, the book [Logarithmic Tables: Containing Logarithms to Numbers From 1 to 120,000, Numbers to Logarithms From 0 to 1.00000, to Seven Places of Decimals](https://rads.stackoverflow.com/amzn/click/com/1290479399) is, unsurprisingly, a 252 page book containing tables of logarithms for 1-120000 to seven decimal places. Or, as another example, [A Million Random Digits with 100,000 Normal Deviates](https://rads.stackoverflow.com/amzn/click/com/0833030477) contains, as you'd expect from the title, a million random digits with 100000 normal deviates, for all your twentieth-century random number generation needs, and runs 628 pages. Special-purpose books of tables also exist, for example [Dudley's Handbook of Practical Gear Design and Manufacture](https://books.google.com/books?id=mLUclpsfTeQC) is 862 pages, and includes a number of tables describing various aspects of sizing gear geometry (e.g. the *dedendum angle* or *root clearance*) for particular purposes. In a similar vein, the book *Fireball* needs to contain tables for computing the required *mean etheric alacrity*, *sub-pentacular glyph angle*, *Hureian correction factor*, et cetera needed to correctly cast a fireball at any particular time of any particular day of the year, in any wind conditions, at the ambient arcanomagnetic flux of your location, et cetera. Some additional features of this model: * Spells can be cast as a ritual. You spend the ritual casting time doing the computation needed to cast the spell. * Spells can be 'prepared', by copying out just the essential relevant information for the expected circumstances. * There can be different version books for a given spell, with different levels of power, versatility, or difficulty. + *Fireball: Leblanch 8th Edition* lists its figures to 5 decimal places, and includes a table for the Arcane Reduction Ratio, which is normally not needed but can be used to enhance the spell. + *Learn2Spell: Fireball* includes just the bare minimum needed to cast the spell, but is much shorter. + *US Millitary Fireball Spell Manual* is a tough, practical spellbook, with direct tables of the exact arm movement speeds and glyph dimensions rather than requiring the user to calculate them from the normal spell coefficients, making it easy to use but resulting in next to no flexibility. * (optionally) Spellbooks can expire - perhaps the table listing the Goldman Factor only goes from 1945 to 1995. * (optionally) Some spellbooks only work in some regions. Perhaps the North American edition only lists the Aldmann Standard Volume for North American graticules as a space-saving measure, while the International edition is much longer but lists it for the entire world. Another application would be to only list marine data for ocean-only spells ("you must be near the ocean to cast this spell"). * Electronic computers will eventually obsolete these tomes. Why would you lug around a 600 page spellbook when you can just download the 'spell coefficient calculator' app on your phone and use that. ## Edit: Mastering Spells Spellbooks are designed so that any sufficiently skilled mage can use them to cast the spell. But some spells depend on properties of the caster - e.g. the mage's height or bloodlines might factor into it. So any spellbooks intended for general use will need to include the information needed to adjust for the user. Part of mastering a a spell would be making your own version of the tables, configured for yourself. Also remember that tables were not the only way of calculating logarithms. For fast, lower-precision computation, a [slide rule](https://en.m.wikipedia.org/wiki/Slide_rule) or other aid could be used. Note that while most real-life slide rules are marked for logs, trig, and multiplication, a slide rule can in principle be made that computes any function. And they don't need to be the stereotypical long flat rectangle shape either. While the extra precision in a tome is needed for it to be general purpose, a slide rule could be good enough if specialized for the specific caster. So, the process of mastering a spell goes like this: 1. Academic study and testing the spell 2. Compute the specific tables for the user 3. Make or modify an existing 'spell focus' (computation aid) to compute the function for the specific user 4. Practice ## TL; DR To cast a spell you may not need *all* of the information on *every* page of the spellbook, but you do need *some* of the information on *some* of the pages, and it's not entirely possible to predict in advance *which* pages you'll need. [Answer] Thinking outside the box here: spells *are* only a few magic words each, but they're buried within 300 pages of meaningless gibberish **for security reasons**. 1. A 300-page book is harder to steal discreetly than just a scrap of paper with the magic words written on it, and also *much* harder to lose or misplace. (Reading from a leather-bound tome with elaborate gilt decoration also looks cooler than reading from a piece of parchment that's been crumpled up in your pocket.) 2. If someone *does* steal the book, they have to sort through all that gibberish to try and find the actual spell. For bonus points, maybe some of the pages have security spells designed to attack anyone who utters them: a thief might read them aloud, thinking they're the correct words, and **BOOM!** the spellbook blows up in their face. 3. Assuming a capitalist society, it also works as a sort of copyright system. Inventing a brand-new spell is hard, potentially-dangerous work, and wizards who do so wouldn't want people taking advantage of their work for free. So they make it so you have to buy the book, and only at the point of sale are you told which page and line the spell is on. 4. For an alternate angle, perhaps magic was once forbidden in the realm. It's dangerous, after all. Spellmakers had to hide their spells inside ordinary-looking books: the first letter of each chapter, the surnames of the first five named characters, stuff like that. Magic is legal now, but the tradition has stuck. [Answer] Because they are flip books. You cannot write down the spell, for security reasons, or because the scribble/book printer automatically would unintentionally perform the spell by themselves. (May be important for dangerous spells, such as ‘blow up the house’.) To read the spell, you have to flip though the book, which causes glyphs (like half-letters) on alternating pages to form the words. This includes some kind of security by obscurity to the non-aware, or maybe androids that try to OCR-read the book, as well. By the way, it is possible to have text scrolling or animated scenes (how to move the magic wand) this way. [Answer] Justification for something like this is pretty easy I'd say. Recipes for even complex food dishes are simple/short. But imagine that the book had to describe, in excruciating detail, the process of farming, cultivating and gathering the required ingredients, and perhaps even the properties and the histories of each of those ingredients. That's going to be one HEAVY book! Weather you want a spell book to be like a recipe-book/instruction-manual, or some kind of magical artefact that simply bestows spells upon a reader, if a spell is the manipulation of the very fabric of the universe/reality then even the seemingly simplest of manipulations could require a very profound understanding of very complex abstract concepts. And for the spell to be truly complete, those concepts may need to be captured in excruciating detail. To cast a fireball, the user may need the magical equivalent of an encyclopaedia worth of knowledge of thermodynamics and all of the interacting forces. Not to mention the initial magical know-how required to interpret the writings or harness the required basic mana/energies (or however magic works in your world). How big does a book get if you try to squeeze in a few extra highly complex understandings woven together in tapestries of wisdom, accessible by understanding only to the select few that can fully comprehend them? Quite big. [Answer] The key insight you need is that the phrase used to cast a spell **is not the spell**. ### Spell Trigger vs. Spell Details If a magic spell consisted of a few words, or a couple of lines like a recipe for cooking, every farm boy would be a level 20 wizard. The reason that magic is comparatively rare in most fantasy worlds is that it is *difficult*. It takes years of study to become a wizard, sometimes decades. That in mind, the assumption that spells are in any way simple does not make sense. ### Spells are like Computer Programs As stated, the phrase used to cast a spell is not the spell. It is just the **command words** to invoke the spell. In computer terms, when you enter "firefox.exe" on a command line, or click its icon in a GUI, this action is just the command you utter to start the browser. The actual browser is far, far more complicated than that. Likewise a spell book. It contains the actual spell, like the source code of a program. Learning the spell is like compiling the source code. Then casting the spell is like typing "firefox.exe" (verbal component) or clicking an icon (gesture). And that's why a spell book is big and yet contains only one spell. Because it details everything you need to know to cast the spell, which is a lot more than just the command phrase. ### Update: Memorising spells This also neatly explains why in some systems you need to memorise/prepare spells - that is basically the equivalent of the compiling process. [Answer] Why would you assume they are the same as cook books? I always think of those things the following way if I encounter them for example in a game, but I never used spellbook based magic myself. Combinations of those are of course desired. 1. There is a lot of literature on one specific method or subject or piece of technology in science or computer science and so on. If you dive deep into a particular subject, things might become complicated and you need time and room to explain all the details. I imagine magic is very complicated since nobody I know can do it. One could also put the entire history of a spell and famous users or uses and so on into a book. 2. In computer games, we break down what might be (virtual) reality into some simple simulation. The book "iceblast" might describe several variations of the iceblast, but for simplicity (one needs to operate the game with some controller and very quickly), only one, maybe averaged, iceblast is implemented into the game. The *in universe* book then contains how many iceblasts you want. Think of it as a cookbook on a particular subject, for example soups. One soup in the game, but many soups in the real world. 3. Long Books might not be practical. So you want to teach one spell, why not do it in the form of a small booklet or scroll that has maybe a couple of pages? Why should every book be a thousand page long encyclopedia that your magic student has to browse through? When you where a student, did you ever receive a couple sheets of paper from your teachers with some sort of information on a particular topic or did you always get massive books form them where everything humans know was collected? 4. So you invent/discover a spell. You want to sell/distribute it. What do you do? You don't start a major project and collect all other spells known to man. You just communicate what you've got and be done with it. I also believe that one could write one (maybe not that large) book on one particular dish with its history and variations and so on, but since most humans don't want to eat the same thing over and over again, one usually doesn't buy those books. But they even do exist. Check out a local dish that's good and you might even find a couple of books written about it. [Answer] Why do you think a grimoire consists of pages of paper? Because every page only contains **ONE RUNE**! The shape of the rune must be drawn in a precise manner, lest the spell's power is diminished, or worse, backlashes to the caster in a spectacular manner. Besides that, each page is **thick** to allow the magic ink to properly seep into the pages and withstand the aging. If a spell requires 20 runes to be properly cast, then you can see why a grimoire can only contain one spell. Or maybe, one half of a *Summon Meteor* spell? [Answer] A single spell could be complex enough, with enough actions and thoughts that must occur within a short amount of time, that it requires a regimen of training to be able to accomplish. That regimen is in the book. Suppose I have a spell that builds a bridge across a chasm. Any inaccuracy in the wizard's imagination makes it collapse. Suppose I have a spell that raises a castle from the ground. Any slip in the words results in a useless pile of rubble. Suppose I have a spell that can cut a forest of trees, split them into boards and fly all of that into place as a nearly impenetrable barricade: Slip up and you have a pile of trees, or worse, a forest fire surrounding you, or you (the wizard) are impaled by your own magic. Some spells are easy, but big spells are like playing a piano concert flawlessly: They can take months or even years of practice for the wizard to learn and embed in "muscle memory", and the book shows you exactly HOW to practice the big spell without killing yourself or destroying your house. [Answer] I think your missing one very important aspect of books. They come in all shapes and sizes. Spellbooks are not 300 page leather bound monstrosities, they are in fact the magical equivalent of the leaflets you pick up at your nearest tourist information, anywhere between 4 and 20 pages depending on the spell. Spellbooklets if you will. You might struggle to use this reasoning if referring to a tome as that word most specifically refers to a large book, but if you combine this idea with some of the other answers (a variety of complex information is required to learn a spell beyond a mere incantation to be repeated, or each page contains single phrases or runes in large writing for ease of reading). Conveniently this also explains why you can carry a lot of them and makes it more believable that they are consumable items that can only be used once. [Answer] If you expect to sit down, read a spellbook like a textbook, and learn something about magic, you've got a long way to go. The first lesson any student of magic learns is that you *can't* learn how magic works or how to control it in the way you'd learn to understand and control mundane things. If you look in a spellbook, all you'll see is incoherent gibberish, scribbles you can't seem to quite focus your eyes on, like optical illusions without the trickery. Just like some illusions make more sense when you learn to relax your eyes to focus at a point beyond them, to receive the knowledge contained in a spellbook you must relax your mind and allow the imagery to become your thoughts. The goal isn't to make sense of the lines, because they already make sense - they are a pure expression of the very essence of the spell they describe. Instead of conforming their wisdom to your mind, you must form your mind to their shapes and motions. You must memorize every subtle detail of their intricacies and visualize each page as part of a larger, super-dimensional sculpture beyond space and time. In so doing, and with singular focus, your thoughts create the ebb and flow of energy throughout your nervous system in such a way as to channel the effects of the spell into being. There is no way to verbally instruct this process - the signal patterns your brain must form are beyond description or control. There is simply too much information. Should a madman actually attempt to write a treatise on a single spell and live long enough to succeed in expounding only the necessary details of its nature, he would fill a library. So really, it's amazing that a single book is enough at all. [Answer] If you take physics, it is similar. The laws are extremely complex. Yet we use them without ever knowing. We use them in tools and matter. These things just "know the stuff". But if you would to construct something like your own matter and dictate it laws to obey, that needs lots of knowledge ( quantum mechanics, chemistry, thermodynamics, mathematics...) Now if you give the mages a gift to "get whatever they can imagine", but make them do it from scratch (from "atoms of magic") then you need a whole grimoire just not to kill yourself in the process. From this point, you can even scale the difficulty by demanding some complexity ( for example the level of proteins <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3032381/> - just a random paper about problems and difficulty scale of these little beasts) you can give your magi a problem worth of many books and half of live. [Answer] The words the spells are made of could be alive in some form. They need a whole book of lesser, regular words they can read and feel superior to. They would burn themselves away if they just existed on a scrap of paper (the're better than that). If you put 2 spells together they just fight and either one removes the other, or the whole book goes up in flames. [Answer] One spell may have many variations in application, for example, a slowing spell: * May be broadcast affecting everything but the caster * May be broadcast affecting everyone but the caster * May be focused on an area * May be focused on an individual, or a pack of animals * May be focused upon one object * Additional rituals may be required to act upon flowing water, rising water, falling water (rain), wind and fire * Other variations are necessary for slowing factor and duration * Surroundings also make a difference, confined and open spaces, and whether the subject is already magically affected, or for a remote subject. Basically, although there is only one spell, there is much that must be learned to cast it effectively in all circumstances. OR Why can't you have a one page book? [Answer] You may make the spells either complex enough to justify "one book per spell" attitude or introduce some sort of pathological capitalism where sellers just divide books of spells into separate books for every spell to earn more selling them. Or just introduce some curse for ones printing wrong combinations of spells together. To make spells more complex you may want to make them something more than "just chant this word loudly". Like explaining the emotional state you have to be in, the intonation, magical rituals that you have to do in order for a spell to be effective etc. Then all these things may require preparation: you need to meditate to alter your feelings and mind state, you need to prepare objects used in the ritual. Additionally the book may also contain some justification for why it is done this way and "scientific" ("magical") explanations. This way you get enough content per spell to make it reasonable printing one-spell book. [Answer] The reasoning behind that is matched with how the spellbook act. If, for example, the book is destroyed in the process then the book doesn't really exist. It's a manifestation of the spell, the essence or the idea of it. The reader is actually enchanted with the spell as items are enchanted with runes or buffs. That's also explain why the books are so rare and pricy. The second option is that a book is real, written by someone and it can be passed through generations. Then the idea behind one spell per book is that when writing a recipe for a cake you don't make a cake. But when you write a spell you are making the spell. Kind like placing a rune. It's active but you can read it and learn what type of rune it is and so on. So for the safety of the writer, reader and the knowledge you don't put two spells in one place. Or you don't put different spells together. Fire spells can be written in one book (assuming that their power is not stackable). But putting fire and water spells next to each other would render them "broken" over time. They would act on each other in a way that some words, incantation, hand or wand movement would disappear from the page. And they would do so until one of the spell stopped being a spell. [Answer] The grimoire doesn't teach a spell in the same way a text book does. The book actually doesn't say anything at all about magic or casting or anything related to it. It was just a book of stories. The more you read the book the more of the book you can see\understand\read. Only by reading it over and over would you be able to eventually see and read other parts and only by reading the entire book multiple times would the potential for a spell begin to imprint itself on your conscience mind. It might be a book of gibberish or a book of fairy tales. Its the act of reading the book is what is required to learn the spell. Gradually the act of reading the information programs your brain to enable it to cast the spell. The more often and the more times you read the book the stronger your ability to cast the spell. Once its cast the energy potential built up by reading those specific words in that specific order is expended and must be built up again before it can be cast again. The ability to write a book to teach a spell is a ability and artform all its own. Perhaps the author of the book can't actually even cast the spell themselves. Like the author of a musical symphony may not be able to play every instrument but listening to the symphony he writes for all those instruments invokes images and feelings even though in reality it's just a series of notes that actually have no emotion or imagery of their own. "Evil" spells have dark stories to learn a truly hideous spell the composer uses truly evil stories that gradually effect the reader as they read the stories again and again. "Good" spells likewise have good stories that likewise effect the reader. Either way being forced to read a given story again and again to imprint the energy on the caster is going to have effects on them. Easy spells might just be a poem on a single sheet that imprint themselves easily. More complex spells might be multiple volumes that each take weeks to read so to build up the potential for such a spell might take years or even a lifetime of reading gibberish that gradually drives most would be casters insane. [Answer] Spells are hard. I mean, I can show you a fast fourier transform equation. But knowing how to use it would require a decade of mathematical background and study. Spells are the same, but each and every spell is its own entire discipline of magic. Casting a spell is a mental effort similar to tap dancing a complicated improvised routine matching a new partner, while doing slide-rule calculations on how much support your suspension bridge needs given cross wind harmonics and expected load, while justifying the cost:benefit to a hostile accounting agency. And every single spell is as different as theology is from chemical engineering. Now, every spell has more primitive versions of itself. There are a series of fire spells that go from being able to light tinder, all the way up to a meteor storm. These are related, and their development was in sequence. Sadly, moving from many related spell to another has a large gulf of "doesn't work very well". Optimized modern spells that are easy to cast have a whole pile of improvements. Back in the day, to prepare to cast a single spell, could spend a week doing rituals and self mutilation. Over time, more efficient ways where found to evoke certain effects. The 'ur fire' style of spell is still used during fire spell research (where you have to 'go back to first principles'), but fireball, meteor storm, flame arrows, burning hands and ignite are all specialized variants. These variants require complex, exact, distinct bits of "choreography" compared to each other to get the effect to come out as desired and as cheap as possible. So for a set of fire spells, knowing other fire spells help, but part of each book is teaching you to *break* the habits of your other fire spells so you don't mix the approaches and end up with a fizzle. Magic lets you break what otherwise seems the rules of reality. But it isn't *easy*. [Answer] Each grimoire contains *two* spells. The fireball spells requires a 10,000 word chant - far too big for use in battle. So the fireball grimoire contains the **prepare fireball** spell, a 50,000 word chant that you cast by reading directly from the grimoire, and which prepares the fireball spell for casting and implants it in your mind, so that you can fire it instantly. Of course, the mind of a wizard can only hold a limited number of spells at a time. This is (my understanding) of how the spells work in D&D, and it seems relevant to you - the spells there require 1 page per spell level to store in the spellbook, you can cast them directly from the text without expending one of your prepared spell slots, it takes 10 minutes to prepare a spell... [Answer] How about a twist on Selenor's answer: In the modern world things stand upon the shoulders of that which came before. It's an interconnected whole that you learn as pieces and put together. (A simple example: Lets look at something that is accelerating. The equation for it's distance is the integral of the equation for it's velocity which is the integral of the equation for it's acceleration.) However, magic dates from a time before we understood that there were a fairly small set of fairly simple rules underlying everything and that the complexity we see is the result of the combination of them. Thus while we might picture the *Fireball* spell as conjuring up some fire, containing it and projecting it to a target location that's not what the book does. Rather, it teaches you everything you need to know to make that ball of fire appear, **without** building upon any other magical knowledge the wizard had. Compare alchemy and chemistry--where the alchemists do not recognize that two different means of synthesis can produce the same end product. [Answer] Pretty late to this question, but I think there may be a more straightforward answer here that I haven't seen mentioned yet. Put simply: **Just because a book contains a bunch of spells doesn't mean they're USEFUL to you.** I'll give some possible scenarios, and back them up with real world analogues. **Scenarios** Imagine: you're a professional battle mage. You've been through your fair share of scraps, you cast a mean fireball, and your magic missile is on point. After battling a dark mage, burning his mansion down in the process, you raid the scorched husk of his library. You pick up the only unburnt grimoire in the place... and it's full of cooking spells. You flip through it, and hey, there's one spell on carving a Thanksgiving turkey that you could adapt, but that's pretty much it. WELL GUESS WHAT! You just learned *Knives of Orc Slicing*. Or perhaps after your latest quest, you go to the equivalent of the library of Alexandria for some light studying (you're a magic nerd, after all). You pick up a book called "Combat Conjurations, Warrior Wizardry, and Strategic Sorcery: Practical Applications" and start reading. You get 10 pages in and realize it's way too simple for you. You flip through, and realize you know all but one spell in this book, and probably better than the author. But hey, might as well pick up that one spell as well. Since that didn't go so well for you, you move to a more theoretical tome called "Military and Para-Military Research Frontiers Pertaining to the Maximal Disruption of Ergodic Systems Utilizing Thermodynamical Processes in Mana- and Time-Limited Situations." This time, you get 10 pages in and realize the 'simple' examples are way over your head. You go checkout some textbooks on theory (with no actual spells in them) to get the grounding you'll need to tackle *Research Frontiers* and spend the next 12 hours brushing up. Upon concluding your refresher, you return to the tome and find you're now able to understand one more spell the text describes. Mentally exhausted, you give up for now. **Real World Analogues** I'm a mobile app developer, and I can do most things in iOS and Android reasonably well – much like the battle mage can do battle magic reasonably well. As in the first scenario, if I read a book about a web framework, I'm probably not going to get much out of it. Maybe a pattern or two, possibly a new way to structure things. The second scenario corresponds to me picking up an "Intro to iOS Development" book. I'm a professional, so I know the basics. Perhaps this book was written recently, so there's one feature I wasn't aware of, but otherwise, not terribly helpful. And I think everyone has experienced the third scenario in some form. Advanced topics are, well, *advanced*, and if your experience so far mostly *isn't*, it can be hard to get through. Moreover, it can be discouraging when you do a bunch of research only to find you barely approaching the level the author is writing at. You might learn *something*, but you're certainly not going to effortlessly absorb all that knowledge. To return to the the question text: if it's like a cookbook, how come you only learn one spell per book? Well, if you already know how to cook a bunch of things, any random cookbook might not teach you much. [Answer] **The spellbooks are magical collections of memories of performing the spell.** If someone tried to describe, in words, how to use a magical spell to you, you probably wouldn't get it. There's all sorts of special terminology that's different between different teachers and different schools of magic. Unless both you and the explainer had the same teachers in the same order, teaching the same spells, you'll get confused by some term being different and wind up blowing yourself up or rotting off a limb or something equally unpleasant. **To teach, show the student what it's like to cast the spell** Rather than either hoping the student understands what the words are trying to say, or attempting to redefine each word in the definition of the spell, the spellbooks are instead collections of memories of different people casting the spell, in different conditions. **One-use device** Many spellbooks are one-use devices, similar to how in many RPGs spellbooks can only be used once and then are consumed. If you want to teach three people the spell you'll need three copies of the spellbook. [Answer] A spell is a merely a complex component composed of many complex components. Spells are layered and stacked, from the most basic roots to the most advanced reality-bending magicks. Simple spells may only require a few key components. A fireball, for example, might require components that extract key elements from the air, components to bring these components together, and components to drive some form of reaction. A component to extract oxygen from the air might be composed of multiple components that deal with splitting/separating the individual elements. A mage/wizard would be able to draw out these components in a way that best fits their own theme. A dark evil wizard might find that certain components can be formed within blood allowing specific uses of blood magic - The actual lines of blood that he draws may be composed of several layers of component spells already. Another wizard may write out / carry runes composing of key components that allow them a variety of uses. A grimoire/spellbook/tome would teach all of the required components necessary to perform some spell. Other books might teach broader theory, layering theory, or theories on producing automated spell matrices to channel through. The bonus here is that a sufficiently talented caster can then work with these individual components-of-components to produce their own spells and new magicks. They might learn a trick that allows them to take a component from a Fire Wall spell and apply it to water instead. Additionally, this would offer a way for one-time spells. Instead of detailing the exact intricacies of how these components are formed and behave, the components are simply laid out in a complex matrix; potentially obfuscated by the mage/wizard to be very difficult if not impossible to properly decipher. The mage who purchased such a book would simply put in their own power/energy/magic, and it would run the complex system of components, burning the "circuitry" in the process. [Answer] I like to think of magic in my stories as being something similar to a computer program or any other kind of algorithm. While the idea behind an algorithm is simple (a sequence of steps that need to be done in order for something to happen), even if it takes, say, 500 lines of code to write a certain program (and that would be a reasonably small program), explaining what you've done is very difficult, and explaining every little concept behind that program can be very well enough for an entire book. Now, Magic would involve manipulating energies and laws that are amazingly complex, and any misstep could lead to "bugs" that could potentially kill a lot of people. So it's entirely reasonable that you would have an entire book teaching a single spell. [Answer] There have been some very interesting answers about the interaction and complexity of magic. But here's something a bit more mundane.. economics. Think of it as if you were in the business of making these tomes. If you bundle the spells up into a single book, you will have to discount it simply because you will be including spells that your potential customers might already know or not be interested in. You would make more selling the spells individually. [Answer] It depends on the complexity of the spell. If you think of spells like computer programs (with potentially millions of lines of code). A well rewritten and complex spell could include many of the most common conditions and variables required to implement it. For example: * If "Day 5 of New Moon"... [[special instructions go here]] * If "Winter Solstice"... [[special instructions go here]] * If "Target Mass < 100kg"... [[special instructions go here]] The book may go into formulas and theory behind the formulas which are all very critical to the success. At the end of the day, this type of book requires a great deal of studying but may not require a very long chant to perform the spell... or it might require months or even years of preparation. Take a look at the "The Sword of Truth" series by Terry Goodkind. "The Book of Counted Shadows" was essentially exactly the kind of single spell book that you are describing. [Answer] The spell book itself is magic, and actually contains some of the magic (if we could quantify that somehow) for the spell. To put two spells into one book would cause their respective magical fields to intermingle and taint each other. Best case scenario, they ruin each others' purity and the spells become less efficient / effective, at worst, they can't be compatible with one another, and rupture the fabric of reality around the book perhaps causing minor accidents (bursting into flames or corroding the things around them or something). The covers of the books contain special magical insulation to keep the magic from leaking out. That only leaves the matter of the content required to fill an entire book. You could use one of the other suggestions above, or maybe the spell doesn't need the entire book - the rest of the content is just the ramblings of the wizard who created the spell, interesting facts, perhaps the theory which lead to how the spell was created, etc. We've to create an entire book anyway we might as well put something in there. So doing this might have become a tradition, respected by those nerdy intellectual wizards... [Answer] I would implement a 'grimoire requirement' thusly: * Some introductory text from the author of the grimoire, because what self-respecting wizard turns down a chance to condescend on *He Who Does Not Yet Know The Thing* * bless the poor unbearded novice * *lots and lots of warnings* * a requirement to get into the right frame of mind - usually accomplished by reading a story or introduction - or perhaps an induction, something like a spelltrance where you commune with the fundamental magic of the universe (please feel free to insert different fluff as is appropriate for the kind of system you envisioned) * and finally dense, literally arcane, gibberish that takes hours to decipher even with the painstakingly inscribed marginalia *and* the assistance of the fundamental magical ether or what have you in understanding words that are not words in a complex language that isn't, on specially *crafted* materials all according to the type of spell you're dealing with. Oh - and some form of magical cryptography, so that the book can be verified as genuine. That would probably go at the front or in the covers, depending upon how bulky the runecraft or whatever would be... And maybe a magical 'lock', which explains why they're single-use. Once you do the purchase, it's bonded to your blood or soul or something. Additionally, the Discworld answer is always a good one (whether it's "spells fight" or "knowledge = power = energy = mass (times c²) = spatial distortion"). It also explains how they all fit in one's backpack or into a *tiny* store - they're literally warping space to fit. [Answer] Make the books into actual books. For example the name of the book is 'The life and work of Thalarous the wise' detailing his many travels and thoughts on philosophy, his understanding of history and at some points his best known contributions to magic, a few spells and potions of which only one is useful to an adventurer like your character. ]
[Question] [ Let's imagine that on one fateful day, John Doe, the absolutely average citizen, wakes up just outside of a small village during the Middle Ages, somewhere in Europe, maybe France or England. Let's assume for simplicity that he knows the modern language of the specific region. Would he be able to survive? What could he achieve using his modern-day knowledge and skills? Could he "invent" or prove something significal? To elaborate more, he does not know much about farming or working with wood or metals, besides being a hobbyist DIY-er, but even there, his skills usually depend on a Home Depot and power tools being available. He does know his high school maths, physics, chemistry and biology, but of course relies on calculators or computers for more convoluted operations (e.g. looking up results of trigonometric functions). He also knows everything that is considered trivially known as of todays standards, e.g. the basic principles of heavier-than-air flight, matter being composed of atoms, the crude anatomy of the human body, the existence of microorganisms, etc. [Answer] ## Depressing, realistic version: John Doe has major problems: * His modern skills are of little use in a medieval English village. The peasants don't care about numeracy or crazy ideas, they want somebody who can slaughter a pig or plough a field. * He has great difficulty communicating with the locals. Have a look at Shakespeare or Chaucer's English, and compare it to the modern version. Remember that pronunciation has changed as well as vocabulary and grammar. He is completely ignorant of local customs and manners, and likely to offend people by accident. (He can probably learn the basic language and customs in a few months, if he lives that long.) * He hasn't memorised the formula for gunpowder, and vague memories of high school chemistry sound like nonsense to the locals. Biology is equally useless. How many of us can identify penicillin mold in the wild, and distinguish it from the hundreds of other molds which will just give you a nasty fungal infection? * He doesn't have the connections to become Royal Military Engineer or Chief Treasurer. This is not a society with a strong interest in scientific and technological progress. Technological change over the span of a human lifetime is almost undetectable; new ideas are suspicious at best, heresy at worst. * He is vulnerable to diseases of the past which have no vaccines (bubonic plague), or against which modern people are not commonly vaccinated (smallpox). One of them may kill him rather quickly. John's best bet is to **find a monastery** and stay there. The monks have some degree of charity towards wandering halfwits who can barely communicate -- and make no mistake, this is how John will come across at first. Once the monks get to know him, they may value his more unusual skills, *especially* his ability to read and write. At worst, John may end up as an unskilled labourer on a farm. At least his good general health gives him a head start, unless he catches some unpleasant disease or bandits burn the village. ## Entertaining version: Through some combination of luck and natural talent, John acquires a wealthy patron or some resources of his own. He becomes a famous inventor and kicks off the Renaissance and/or Industrial Revolution a few centuries early, as explored in Mark Twain's *A Connecticut Yankee in King Arthur's Court* and subsequent works of fiction. [Answer] This really should be a comment to Pavel's excellent answer, but I'm afraid I don't have the reputation to add a comment. Given the sad story of [Ignaz Semmelweis](http://en.wikipedia.org/wiki/Ignaz_Semmelweis), it's pretty unlikely anybody would even listen to your newfangled ideas about the importance of hygiene. His flash of insight was quite literally that it would be advisable for doctors to wash their hands after touching a dead body before attending to new mothers in the maternity ward. Despite having dramatic, incontrovertible evidence that was, in fact, a good idea, he was drummed out of Vienna as a quack. Keep in mind this was mid-19th century Vienna and hardly the dark ages. [Answer] **Depends on how he plays his cards**. The medieval world was disgusting, diseased and woefully violent. Being used to the egalitarian principles of modern times, he would treat the nobles as equals, which might result in beheading or in the nobles assuming they're dealing with a fellow noble. If he can't speak the (for him) archaic local language well (might take him months to learn properly) short term survival might be a serious issue. Given that he towers about half a foot over the locals, probably some military job might become available if he's up for it. Even basic high-school mathematics are insanely advanced by medieval standards, his knowledge of chemistry and biology would top the most advanced theoretical skills up until about the 1600 without even trying. The problem would be one of **access and persuasion** rather than of actually having useful skills. The medieval world is not known for its meritocracy, but for promoting **incompetents of noble birth** over skilled commoners. So his best bet would be to finagle his way into becoming the assistant of one of the less atrocious nobles. This would be a mutually beneficial deal: his skillset would allow the noble to rise meteorically, while the noble would 'open doors' for our time-stranded traveler. If that happens, the sky's the limit: **Royal Doctor** (with earth-shattering advice such as "wash your hands with soap before eating, and especially after using the ba... going off into the woods" and using certain kinds of mold to treat the royal children when they're sick.) **Head of the Royal Mint** (using negative numbers in book-keeping, and, actually, proper book-keeping) **Apprentice or Head Weapons Engineer at the Imperial Court** (Depending on how much chemistry and physics he remembers) But, most likely, he'd get a digestive tract infection during the first few weeks and die of cholera or some-such. [Answer] He would bring bacterias and viruses, that haven't evolved yet with him and after people around him start getting sick and die, they would realize he is the devil and would burn him at a stake. [Answer] Many answers here seem to me excessively pessimistic. Rather than commenting on them individually, let me make some general points: Yes, language has changed since Medieval times, so knowledge of the modern version of the language would be of only limited value. But it's absurd to say that this would mean that the people of the time would think him insane or a drooling idiot because he can't communicate. Medieval people were well aware of the existence of other countries where people spoke different languages. There would be nothing surprising about such a person at all. The fact that he is an "outsider" would not result him in instantly being killed or thought to be a witch or any such thing. While travel was limited in Medieval times, there certainly were people who travelled great distances. Ever hear of Marco Polo? Travelers were usually welcomed because they brought news from the outside world and entertaining stories. A traveler could usually get a few free meals or at least some drinks by telling a few stories. Yes, health and sanitation back then were poor, so the risk of an early death was greater. But it's not like everyone was condemned to instant death. Obviously many millions of people managed to live to adulthood. Maybe you could make a case that there would be diseases circulating then that are not common now, and so he wouldn't have any resistance. At the other extreme: It is very unlikely that he would be able to bring much if any modern science and technology to this place. Sure, he'd be familiar with computers and cell phones and airplanes and all sorts of modern things that these people never heard of. But could he teach them how to make these things? I doubt it. I like to think I'm a smart guy -- Mensa-level IQ, work as a software developer, and all that -- and I'm hard pressed to think what technology I could introduce if suddenly dropped in Medieval times. Yes, I can use a cell phone. But I haven't the vaguest idea how to build one. I know a lot about computers. But build one from scratch? Let's see, microchips are made using silicon and germanium. I know silicon comes from sand. Exactly how do you extract it? Where do you get germanium? I presume that lithium batteries are made with lithium. Duh. Where does lithium come from? What does it even look like? I don't even know what color it is. Even if I had a pile of lithium, how do you make a battery from that? Etc. Okay, maybe that's too ambitious. How about something simpler. Maybe a steam engine. I know it has something to do with boiling water, having a small opening for the steam to come out, and running that steam into a piston to make it move along a shaft. But how to make any of those things? Maybe given the time and resources to experiment, I could figure it out. Or maybe I'd just kill myself when my first experimental boiler exploded. Thomas Edison once said that genius is 1% inspiration and 99% perspiration. Even if you know the basic idea behind some invention, there are many, many details to be worked out to take it from a "basic idea" to a working model, and many more to get from a working model to something that is actually practical. Unless you are an engineer whose job it is to design models of this particular machine, the odds are that you have no idea what the details are. I suspect about 90% of the people in the world have no idea how any of the modern inventions they use every day actually work, and most of the rest have only vague, general ideas. The number of people who know how to actually build a jet plane or a cell phone or how to make plastic, etc, is tiny. And even at that, inventions build on earlier inventions. Before you can make a radio, you need electricity. To produce electricity, you need things like wires and magnets. To make wire you have to smelt metal. To smelt metal you have to mine raw ores. To mine raw ores you have to know what the ore looks like and where you find it. Etc. Even someone who knows how to design and build cell phones probably starts with wire and plastic and semiconductors. He knows how to use copper wire, but ask him what raw copper ore looks like, or where you go to find it, and how to smelt it into usable metal ... Odds are he has no idea. [Answer] **Sad, but realistic story is: Not much**: Let's put aside that most probably he would be burned as witch for appearing out of nowhere. Let's also put aside the fact, that most probably he would die of Dysentery, plague or any other disease caused by poor hygiene standards (Fun fact, both toilet paper and flush toilet were invented in 19th century) Let's even handwave the fact, that he would be probably considered as idiot, because medieval language did differ *a lot* from our modern language and go for happily-ever-after scenario. (English speakers, do read Shakespeare in original edition. How much do you understand?) People were not allowed to travel in medieval ages. You were property of your king. So most probably he would stay in such village. (Or got explained, that he has to stay inside the village). If he were really skillful DYI-man, he would probably become blacksmith of such village. If not, he would become "common peasant" of that era. Because his general well being, he would be "perfect match" for women at that time. So he could pick up a woman he desires most. He would have 5 to six children. Maybe more, maybe less. As I told you. Sad, boring and average story it is. But he wasn't killed or died out of any plague [Answer] An even more depressing take is Poul Anderson's **The Man Who Came Early**. A plot summary from [Wikipedia](https://en.wikipedia.org/wiki/The_Man_Who_Came_Early): > > The story is presented in the first person, related by a Saga-Age Icelander named Ospak Ulfsson. During a violent thunderstorm, an unexplained phenomenon transports the titular 20th-century American GI back in time to Ospak's homestead. The American, who becomes known as Gerald "Samsson", is an engineering student drafted to serve at Keflavik during the Cold War between the U.S. and the Soviet Union. > > > Gerald is taken in by Ospak's family who assume him to be a shipwreck survivor. Although his engineering background gives him many ideas of how to improve life for the Icelanders (such as advanced sailing vessels), his lack of practical know-how, and his oversophisticated ideas when set against the nature of 10th-century life, lead to none of his suggestions being implemented. Knowledge of 20th-century metallurgy does not endow him with the highly specialised skill needed to work in a 10th-century smithy, and his attempt to do so ends with a costly fiasco. Also, knowing the theory of how to design a large metal bridge is not a sufficient base for constructing a small wooden bridge over a rivulet with medieval carpentry tools. > > > There is also a whole series of misunderstandings caused by social and cultural differences. Gerald tries to tell the Icelanders that in his country there are no blood feuds because the government takes care of punishing all wrong-doers. However, his listeners have no concept of a vast impersonal government and its law-enforcement agencies; Gerald's words, when translated into concepts familiar to his listeners, are taken to mean that all law-enforcement is done by the King in person - whereupon the amused Icelanders remark that such a King would be too busy to beget an heir... And conversely, when Gerald tells that he had been a military policeman and describes the task of one, they are astonished at what they see as his foolhardy courage of "offending all the men in the war host" - since Vikings would absolutely not have tolerated the petty regulation of their dress and personal life which is common for soldiers in a 20th-century army. > > > Then, Gerald guilelessly mentions that his family owns no land and lives in one apartment of a big house where many other families live - not realising that he has just plunged his social status sharply down, as in this rural society a landless man is far down the scale. And when he boasts that the United States is a free society, but admits that US citizens may be called up for military service even at harvest time, his shocked hosts conclude that the US is the worst and most monstrous of tyrannies - since in their economy, calling up the farmers in harvest time would doom their families to starvation. > > > Meanwhile, Gerald and his host's daughter fall in love with each other. A rival suitor from a neighboring clan, annoyed at her preference for the "useless" foreigner, insults Gerald, who then challenges him to "fight it out" - not realising that in this society, duels between free people are fought with weapons and often to the death, and that fighting bare-handed "is for slaves". Trapped in a holmgang and about to be cut down, he uses his gun and kills his opponent. > > > In order to avert his host becoming entangled in a blood feud, Gerald departs on his own - which leads to his being outlawed and hunted down. When making his last stand, his ammunition runs out ("his magical weapon failed him" as the locals see it) but he gives a good account of himself with a sword seized from a fallen opponent before being finally killed. > > > The ending of the story suggests that, in time, Gerald's burial barrow would come to be regarded as the tomb of "an ancient hero" and that he would in death find the place in Icelandic society which he did not gain in life. > > > [Answer] # If he knows some medieval theology Royal Canadian Bandit's answer mentioned him going to a monastery where they would end up valuing his skill to read and write. Now, it just occurred to me that **if** he's a christian and followed higher level secondary education with Latin (this is still the norm in a lot of developed countries) and at some point he read up on some medieval theology he would definitely be taken seriously by everybody. His knowledge wouldn't even have to be extremely in-depth. Like having spend a couple of afternoon reading Wikipedia articles or the excellent Internet Encyclopedia of Philosophy would probably been enough. The interesting thing to understand is that the sciences were traditionally seen as sub-categories of theology (which sounds totally ridiculous to us nowadays, but the natural being sub categorized to the *super*natural actually makes a lot of sense in such a society). So if he can establish some basic authority as a good theologian (claiming he's a wandering monk or what not, something that is technically true as he just wandered from the present to the past), he can **next** start thinking about the other sciences. And depending on what he still remembers work from there. # If he does not know anything about medieval theology On the other hand, if he doesn't know the above stuff (quite likely) he won't be destined for any greatness. If he accepts being a normal peasant he will probably do just fine, if however he tries to become self important and introduce modern technologies and stuff that will soon be the end of him (nothing dramatic like being burned on the stake, just nobody willing to trade with him or help him\*). And yeah, if he's a christian (or is capable to act like one), but not all that learned then just going to a monastery would be the wisest choice. \* Most of medieval times weren't half as barbaric as depicted in modern media. Realistically it depends on what he would say though. If he starts proclaiming post modernist notions or even modernist notions the Church would take interest probably and excommunicate him. But besides that he would be more likely treated like an idiot than 'burned on a stake' like some of the other answers suggested. PS. This is assuming that language is not an issue, as that's how I understood the question. And just for the record, it's not that faith was *that* much more important in that time, but there are only two theoretical powers where he could flourish: political or theology. The first requires the right bloodline and the second requires knowledge. [Answer] The first challenge would be just to survive and for him to establish himself. Many medieval societies did not treat outsiders well. He would have no travel permits and no one to speak for him. Village communities would shun him and cities could deny access. Language barrier will be hard to overcome and despite being literate he could not utilize this skill to the fullest. Perhaps if he had taken Latin in high school and paid attention he could use that for rudimentary communication. As others have stated without any specific skills and almost NO actual skills for the time period survival would be hard. Even many simple innovations require a lot of supporting technologies and skills that would not be available to him. I wouldn't say that he would be completely useless. He would have a lot of information but much of it would be hard to demonstrate or utilize. He would know world geography, stuff about hygiene and biology, even some history what will happen, math etc. but good luck demonstrating your value. With out any usable skills he would require a benefactor but I think he could prove quite useful in the long rung. [Answer] Once properly adjusted to the nuances of *Olde English*, I think your man (and most others from our time) would have an excellent career as a storyteller. Just imagine: Gather 'round children, and listen to my tale, "**Geo geara, fram heofonsteorra ealfela feorran...**"\* \*constructed with this nifty tool: <http://hord.ca/projects/eow/> [Answer] The first problem is: Immediate survival. People will find him extremely strange: He is of excellent health (people needed to work extremely hard from childhood, damaging their bones and sinews, they had plagues and were badly nourished. Even the rich ones like nobility were eating too much wine and flesh, overweight and gout was rampant. While often very robust because they survived this environment, the body took damage). If he is a white-collar worker, his hands were soft which would indicate higher status but his behavior does not fit. His clothes were strange and if unlucky, could kill him at once. Wearing purple was reserved for nobility and punishments in medieaval society were almost always capital punishments. It should be said that it must be a "him" because "her" survival would be either marriage (if lucky) or prostituition. Having no rights and respect at all it would be nearly impossible to get out of the trap. As several people pointed out, the known sicknesses could kill him very easily because he is in another environment. **The lucky ones**: Craftsman and ranchers who are still not fully technologized. They could be found e.g. in Amish cultures, rumors have it that even now there are blacksmiths, goldsmiths, bakers, carpenters which would be able to continue their work in a medieaval society. In cities there were guilds, so they needed to join them but I think it could be possible. White-collar workers had a very good opportunity to survive: **Healer** The knowledge of medicine was so unbelievingly abysmal that having visited a first aid course and common knowledge would set you apart. Barbers were responsible for teeth and chirurgy and were often quite competent at it, but the prohibition of sections meant that the knowledge teached were garbage. We know that the ancient ones did very good operations, but in medieaval time corpses had unsetted broken bones. What's better: Calling yourself a healer was not prohibited. * Hygiene and sickness: People died on infected wounds all the time. The extremely painful tetanus infection killed many people. Appendicitis was a death sentence. Simply washing and sewing wounds were unknown. * Bumbling: Bloodletting was the standard (and useless) procedure. If you have diarrhoea, you could expect that they tried to put a cork in the ass... I am not joking. Burns which could be treated with cold water were coated with butter. * Mouth-to-nose insufflation. You could not believe that even in the middle of the 20th century drowned people were treated with arm aerobic. Alone using that on victims and resurrect someone would be unbelievable. While having very advanced knowledge, you needed to learn herbology (by practitioners or reading) and chirurgy (probably self-taught: barbers were often competent, but had low social status). [Answer] The average human from the 21st Century would do as poorly or even more poorly as the pessimistic answers provided here. Even very smart people with advanced educations would *typically* not do much better - their knowledge would be too specialized. I have multiple engineering degrees and interests in many other areas. But most highly technical people these days are way too specialized to be able see a project through from beginning (finding appropriate minerals) to end (fine tolerances of a gun's chamber). Furthermore people with the right knowledge may not be dropped into an environment where necessary resources are present (which of us could find iron ore in England?). Given some local labor and proper mineralogy in the area, I would eventually be able to smelt high quality steels based upon my geology & metallurgy classes but I likely could not do it without local help and my first several batches would most likely fail. The same is true for gun powder and gun cotton. I understand the general methods of making these but don't know the proper ratios etc. It would take favorable local mineralogy, chemistry (how many of you can manufacture nitric acid or potassium nitrate?), and some willing local labor to put these things together. I live on a hobby farm and know moderate amounts of animal husbandry and modern farming practices so I could probably help improve crop yields. But what use is my knowledge of growing melons and corn if I was dropped into Medieval Europe? With modern wood working tools, I have created my own bow from local wood but have no idea about how to create the bowstring. Unlike the protagonist of A Connecticut Yankee in King Arthur's Court, I haven't bothered to memorize eclipses from many hundreds of years ago, so that approach is right out. So I suppose the real answer is on average, the modern man wouldn't do very well but **some people** might be able to do quite a bit if they were dropped in the right environment (near the necessary resources or otherwise where their knowledge would be applicable). [Answer] It might not sounds like much, but you could actually achieve quite a lot, assuming you could survive and convince a wealthy person that you have value. 1. Printing press. This was amazing, and the technology required for a basic version is virtually 0, it was just no-one had the idea first. For mass printing of something, say the bible, you can literally get a cylinder of metal with raised letters on it, cover it with ink and roll it down a page. Want to print 10,000 copies of the bible? Gonna be a lot quicker and more accurate with a bad printing press than by hand. This is widely credited as causing a dramatic increase in literacy rates, as there were a lot more books to read. 2. Weaponry. Forget guns, too hard. What is saltpeter anyway? Crossbows and pikes could be made easily by a time traveler and a couple of bowyers/blacksmiths. This made the poor significantly more even in combat against the rich (although I believe also led to people conscripting larger armies of farmers, and thus starvation) So maybe don't do this? If you wanted to make guns better, you would be best of creating a revolver (easy, all you need is a trigger that makes a hammer strike a bullet and rotates the chamber containing the bullets around. Easy enough for any blacksmith, and then when someone who knows chemistry comes along and discovers gunpowder, all they need to do is package it into bullets and you have advanced guns significantly. 3. Trains. Coal (I assume most people know of an abandoned coal mine?) gets burned, which heats water, which turns a fan, which turns an axle, which turns a wheel which runs along a metal track. Congratulations, you have revolutionised transport. 4. Science. Most people know enough science to help significantly. They would need to write down hundreds of facts that they learnt off the news, and run thousands of copies through the printing press they built. This is because 99% of these books will be burnt for heresy. After several of your scientific declarations are proved, people will start to take the rest seriously. Most people with a high school education would be able to; point out that light is a wave and a particle, if anyone doubts you, suggest they pass it through two slits and look at the interference, recommend pea plants as a good simple thing to look at when considering evolution and determining the difference between dominant and recessive traits, give scientists confidence that if they are looking for a particle that gives everything its mass, they just need to build a bigger circular ring and accelerate particles faster. Point out that matter is not made of plum puddings, point out that God does play dice with the universe, make the statement "lets assume that all observers see light at a constant speed relative to themselves, and thus time must dilate, length must contract, and mass must dilate." A mathematician would be able to go from there to relativity, relatively easily. Introduce the periodic table and fill it as far as you can remember. None of these would be useful immediately, but they would be extremely useful for the next 500 years. 5. OH&S - Give some dire warnings about the end of the world - asbestos, CFCs, CO2 emissions. As you are now the most famous scientist ever, people will listen to your warnings, even though you are long dead. 6. Other engineering stuff I thought of now. Abacus (assuming you land in Europe and not somewhere it already exists), penny-farthing bicycle (no need for rubber wheels). There are a lot of inventions that you could vaguely discuss/draw picutres of, which would assist real inventors down the track. As with almost everything I have suggested, it would help years after you were dead. I'm trying to help humanity, not the time traveler. Trebuchet (just a catapult where the rock is in a sling attached to the end of the arm), the concept of arch/suspension bridges. Arguably, you could invent a relatively decent typewriter, although it might end up breaking too much. 7. Health - propose washing of hands, eating lemons to avoid scurvy, moving latrines further from food preparation, and recommend people investigate moldy bread to prevent infections. As with science, all of this will be ignored immediately, it just means that when one of these things is accepted, all the rest will be investigated. 8. Extremely modern stuff that you could describe, write about and draw, thus cause to be invented a bit early. The roller-ball mouse, airbags, dvorak keyboards, snuggie [Answer] There are many low tech inventions, and conceptual frameworks that could turn the tide of a war or make a person rich. ## Scientific method The idea that you can understand the world through iterative experimentation comes from the enlightenment. This is a powerful framework in which to work. ## Bicycles Constructing a simple bicycle requires a decent knowledge of ironwork. An army equipped with bicycles could cover 100 miles in a day and arrive fresher than an army which has marched the same distance. ## Batteries Construct a battery from steel and copper plates plus lemon juice. stack enough of these together and you might even be able to create an arclight. ## Carbon Steel Cast iron is brittle. The addition of Carbon atoms, readily available from wood makes iron much stronger. Take your molten iron and chuck in some branches. Presto, your swords are sharper and stronger than the warlord next door. ## Generator Generate electricity by spinning a magnet in a copper coil. A piece of magnetite should do the job. This also possibly opens the way to induction hardening. ## Navigation by compass We don't know for sure when people first realised that a piece of magnetite floating in water would align itself north-south. It may have been as late as the 15th century. A magnetic compass would provide an obvious advantage to anyone wishing to navigate on a cloudy night. ## Crossbows Crossbows are simple powerful, quiet weapons. The man who invents the crossbow would be put in charge of many things. ## Kites Kites are simple to construct. A large enough kite can carry a man, giving a medieval warlord superior scouting capabilities. ## Central heating The Romans knew about this, it's not hard. Have a slave heat water in a boiler, then pump it under the floor. A nice warm house for a nobleman. ## Plumbing Water can be transported from place to place via a lead pipe. A low tech solution that makes a fashionable nobleman's life better, until he goes mad from lead poisoning of course. ## Cryptography Medieval codes were simple substitution cyphers. A modern person with a basic knowledge of probability ought to be able to crack such a code with ease, and could easily come up with a stronger code. ## Triangular sails Medieval ships had square sails which meant they could only move if they had a following wind. More modern ships have a triangular sail with a swinging boom, plus a deep keel. This means they can sail across the wind and tack into the wind. The advantages here in terms of warfare and commerce are obvious. ## Mechanical loom A mechanical loom can be constructed from wood. With a little thought our modern human might be able to work one out. ## Ball bearings Ball bearings dramatically reduce the friction in a wheel. A coach or chariot equipped with ball bearings can move faster with the same number of horses. ## Sprung suspension Stagecoaches used a large metal spring on which the coach itself was suspended. A simple innovation providing greater comfort for travelling royalty on bumpy roads. ## Reading glasses Slightly trickier this one, but presumably long sightedness among older people was an issue in the middle ages just as it is today. Glass was available in medieval Europe. Given time and persistence it could be shaped into a convex lens of great value. A convex lens can also be used to start a fire in sunshine, which presumably would have looked like the most extraordinary alchemy. ## [Burning glass](http://en.wikipedia.org/wiki/Burning_glass) weapon A large concave mirror made of polished metal can concentrate the sun's rays on a target, perhaps a ship, a siege weapon, or an enemy general. A burning glass may have been used by Archimedes as early as 212BC. Of course you would need sunshine for it to be effective. ## Printing press Books were expensive. The concept of movable type would not be hard to replicate. A person with a printing press could be rich. ## Zippo lighter An oil soaked rag in a metal box, plus a flint and steel. Magic instant fire in the palm of your hand. [Answer] John Doe would know some very important facts.... he would be able to draw a map of the shape of the world freehand. He would know where the largest oil deposits in the world are and what oil can be used for. He might know where the largest Gold deposits and diamond deposits could be found. He would be able to predict the future to some extent. Every place he went he would see people doing things in ways that could be improved.. printing presses, looms, plows, dams, mills, etc. He would make alliances with kings and probably become so powerful he would be get himself beheaded. [Answer] Yes he will, but don't expect anything fancy. I'll try to explain why. First, even if he had his gadgets on him, they would either not work (e.g. no Internet to look something up on his smartphone) or would not work for very long (i.e. no power to (re)charge the device). So, John has to work from memory to get things done. As you postulate, John isn't very skilled at anything in particular so he would need others to help him. Charity used to be something very different from what is nowadays considered to be the least one can do for another, so John doesn't have to count on anyone helping him getting food, shelter etc. He needs to have or do something to earn it. He will not be able to build something to aid him in his quest for his basic, everyday needs, so he will have to put his knowledge from the future to good use. As he only knows some high school topics (and probably not with a great deal of depth or precision), he will not have some "magic knowledge" readily at hand to make people stand in awe. He will not have or be given the time to experiment with what he remembers to get something. What he can do, is get a job like anyone else. Working as household staff or joining some noblemans private army will get him a roof over his head and food. It will not be a live in luxury. I really see only one way out for him to use his knowledge to acquire wealth and fame: if he is able to whip up something that can be used as a weapon, that will give him a chance to win over the favor of a nobleman. If he succeeds at that, he might survive. [Answer] Lets say this guy gets past the first hurtles of surviving. Finds a place in a village where he can live a life, although a short life. I think this is perhaps the crux of the question, the guy arrives, settles in for a time, ponders what he could do to change the world with his advanced perspective. What could he possibly come up with, given the lack of resources and technology of the time he found himself in? The printing press is the thing. Easily built by a dedicated hobbyist that has been able to secure a few connections with a furniture maker, maybe a black smith and a supply of lead. To the basic machine, improvements would come later. We know it can be built at the time in question, because it was. Knowledge is power, but knowledge is useless if there is no medium for it. The most talked about thing in Western history is Martin Luther's thesis, and how everything changed in the religious world when he posted them on the door. Luther did not have an original concept on that door. John Calvin pretty much had said everything Luther posted a century before. I believe that it was about a half a century after Calvin's time that Guttenberg invented the printing press and the another five decades before Luther posted the thesis. During that time the printing press was catching on. Literacy rates were climbing, more people had access to printed material. In towns mass advertising was beginning to appear (Yes Spam!). All the things that helped Luther become the father of the reformation were in place. The reformation was the biggest, but by no means all that was going on. Knowledge was being recorded and much more widely distributed with each passing year. This spread has not stopped the Internet and SE being direct descendants of the Guttenberg printing press. It is said that the ancient Greeks were on the edge of an industrial revolution, but then the library burned, no back ups, no redundant storage, information was not widely known, most of it was lost. If they would of had a printing press, who knows we might be in the dark ages now having ran out of oil a couple of thousand years earlier. All the things that came after the printing press if not made possible by the printing press they certainly made more practical. Everything simply changed and became more accelerated as the flow and archiving of knowledge increased. The invention of the printing press marks the beginning of the modern era, without that acceleration in the archiving and dispersion of ideals, invention, communication etc., we would still be in the dark ages. The guy would likely die in obscurity, start ups at the time being pretty rough. That's one thing he could put together to change everything. [Answer] Most of the other answers here present suitably pessimistic assumptions, but you should remember that you do not have deviate that far from normal to invalidate your core assumptions. For example if my uncles were sent back, they would do just fine. D is a blacksmith and shepard, is building a bloomery and an accomplished storyteller. S is also a blacksmith best known for his decorative work and an instrument maker. My father would either become a well respected teacher or killed by the catholic church for his knowledge of the scriptures. But for some real outliers, just step back a generation. My paternal grandfather built a crane from scrap, cut gears by hand and was an acceptable farmer. On the other hand my maternal grandmother would have been burned as a witch. [Answer] Let's assume he lands near a village. First off, since he has no clue that he's just time travelled, he will try to figure out what is going on. After several failed explanations, he will try to communicate with the locals, who will consider him half-mad, one, for the lack of language skills, and two, for asking stuff like "Do you know where I came from?" or "What is this place?". He will take a lot of time (if he didn't take history lessons) to realize that he has, in fact, time travelled. After that, he can either try to convince the people that he is from the future (which will lead to him being laughed at and considered totally mad) or he can accept the fact that he has to live there for the rest of his life. He will have to learn the ways of the people, including the language, the culture, and get to know their level of basic understanding of science. Having a high school level education **might** be of some help. But that is just a possibility. Most probably, if he tries to teach the locals science, no one would even bother to pay attention (because he is considered mad). However, it could happen that for example a travelling local discovers a new fruit from a new land (which is widely available in modern times) and our hero predicts it's taste and other properties. That would hardly be enough for the locals believe that he isn't mad, though. After a series of events like this (very improbable) maybe the locals would start to listen to him. Still, as mentioned in other answers, building his own weapons and tools would be hard because of his lack of smithing knowledge and/or unavailability of the proper materials. Applying his high school knowledge, thus, would be very difficult. Assuming everything goes his way, he will find a person that knows how valuable he is. If that person is 'good', he will help our hero with whatever he wants to do (example taking up some job or writing books, as mentioned in other answers). If the person is 'bad', he will lock up and torture our hero and will gain as much information as possible and credit it all to himself. In the end, our hero will either be dead, tortured to the brink, gone insane, or, in the best case, be doing well. This is all assuming that he doesn't die/get injured of other causes first, like diseases and/or war. [Answer] Seems like a terrible omission to not include the wonderfully funny work of Dara O'Briain (4min video)... [Dara O'Briain explains modern technology (YouTube)](https://www.youtube.com/watch?v=BVxOb8-d7Ic). In short, we'd be useless even if taken seriously! While we're great users of modern technology extremely few people know enough about what we use everyday to be able to guide someone trying to recreate it. Dara works this by explaining that even if we know how our computers and toaster etc... work we draw a blank at what happens after they connect to "the wall". [Answer] Presuming weve got past the language / culture / disease issues mentioned in other answers, you might be able to do demonstrate something useful with electromagnetism. Even without any hands on experience, anyone one with a reasonable high / secondary school education should have a basic understanding of the key concepts. Iron would be relatively easy to get hold of, copper aswell. Providing you can find some way to create copper wire, fashioning a basic electromagnet should be relatively simple. Getting a relatively constant supply of electricity would be more complicated, but linking up your electromagnet to a rotating wheel would at least allow you to prove the concept. Provided the locals dont decide to burn you as a heretic, you should have attracted enough attention! [Answer] I suspect surviving in this situation might be easier for someone without a high school education, a child. Providing someone picked them up and cared for them (I think this much more likely for a child, children were valued for manual labour), they could grow into a normal medieval adult. Children learn quickly, and often more readily except things they don't know, so I think a child might be able to adapt to this situation much easier than an adult. I think there is less chance of a child being seen as a witch, or knowing too much that they get on the wrong side of a noble. Obviously you do have the problems of children being less resistant to disease, wanting mummy, etc. (Perhaps this is not what you were imagining in answering the question, but maybe it was interesting) [Answer] If our time-traveler is a fan of Dinosaur Comics, there is any chance they have a copy of the [Time Traveler Cheat Sheet](http://www.topatoco.com/merchant.mvc?Screen=PROD&Store_Code=TO&Product_Code=QW-CHEATSHEET-PRINT&Category_Code=QW) either memorized or printed out and stored in their wallet. Assuming the latter everything will go great, they'll be "inventing" and "discovering" all sorts of useful stuff until one day a jealous cohort will notice them looking at their cheat sheet, realize it is the source of their "power" and kill them, steal the sheet and take their place as the provider of awesome anachronistic newness! [Answer] He could have a profound impact If he established himself to the point where he become known as a learned individual. If he was able to source metal and magnets (both of which are available), he would be able to at the very least demonstrate and create short range electrical signal system. If he paid attention in high school physics he should be able to be a huge teacher of basic math, and even calculus, surpassing easily the smartest scholars. I'd he paid attention in physics, he should be able to derive Newtonian mechanics, which would have a profound impact on builders no longer having to build by trial and error at full scale. His biggest impact would be in health. Simply knowing about germs and washing hands, boiling things to clean them, or before surgery, segregating those coffing/sick covering mouth etc. Would have a profound impact on the spread and rate of sickness. If he knew principles like how to conduct double blind experiments, he would certainly leave a foundation for renaissance, as he would be able to prove things to people. Even basic things like using metal tools for farming was not done in the middle ages because people were worried about poisoning food, no one ever thought of testing it though, it was superstition that didn't break until the American revolution!!! I think he could have a profound impact. He would need to keep all this uber his hat until some community accepted him. And he would need to roll them out in a way where it was seen as natural and beneficial. [Answer] He might be able to make a go of things if he knows foreign languages, such as Spanish, French or German (if he is an American it is unlikely that he would have learned Latin). Although these languages will also be very different from their current versions, he will still have the ability to communicate with foreigners, such as merchants and sailors or foreign mercenaries. These are skills which the nobility and various guilds will be *very* interested in, and constant application and practice will improve his skills rather quickly. [Answer] Many answers have told the pessimistic view. Since I don't know exactly the year which he arrived, I guess he could do/teach the following technologies: * hot air baloons * steam machines * steel and nitriding steel * gunpowder (he might not know the exact composition, but might have some idea which would accelerate experiments to build it) * galvanic cells * radio trasmission (using sparks from galvanic cells) * advanced mathmatics (one doesn't need to know by heart all the values of sin(), cos(), if they know how to calculate them) [Answer] The average human did not live to adulthood. Just by being around, he's not *average*, but lucky, fortunate, and skilled enough at surviving. The last item is still important even if you postulate that an adult popped back in time without having to survive up to that age in that environment. Knowing how to use a crosswalk safely in a busy urban center, the emergency services phone number, how to use credit cards wisely, etc. will not help continued survival. An *average* random person, even after removing those who died from disease or poor fortune, does not survive. One has to develop skills for surviving in that environment, and your traveller will be rather poor off in that regard. [Answer] From another perspective, there are many novels which explore how to bring primitive humans up to "modern" or even more advanced technologies. One such example is the [Safehold Novels](http://en.wikipedia.org/wiki/Safehold). In the case of these specific novels, the protagonist has many non-primitive resources to fall back upon to aid in his advancing the primitive culture. However, other novels using different assumptions are available. In [Earth Abides](http://en.wikipedia.org/wiki/Earth_Abides), the protagonist attempts to first bring primitive technologies to the survivors and then help them advance. I suggest exploring the available fictional novels available for various treatments of the issue. [Answer] Rock and roll star (yes, I'm serious here!) He probably doesn't remember any of the formulas for useful medicines or inventions, but he DOES have a recollection of centuries of popular culture which he has consumed his whole life. He probably couldn't recreate movies in play form (though on second thought, that would be pretty cool), but he can rework popular songs to suit local (temporal) tastes. He doesn't really even need to know much about music, just find a minstrel and hum him the tunes. If this works, he could even end up with royal patronage like Mozart got (this guy probably recalls some Mozart, so this isn't too unrealistic). [Answer] Your modern basic understanding of how things work would put you under continuous stress to play dumb. Any exhibition of superior intellect would bring immediate suspicion from those you try help. You would either be killed or jailed as a heretic by the Church or nobility or burned as a witch by ignorant locals. Ultimately it would be living conditions that would do you in. You would be unable to eat without contracting some food bourne illness like cholera. General lack of sanitation would expose you to plague,tuberculosis,flu,pox...etc. If you managed to avoid those things, your best hope would be to gain the favor of some noble by mastering the improvement of some of their weapons if your level of knowledge would permit that. As a peasant, your access to the nobility to even accomplish this would severely limited. ]
[Question] [ I'm trying to write a 'gundam like' series, though with space fighters instead of humanoid robots. I want a semi-hard science world, I'm okay with making up technology without fully explaining how it works so long as it seems plausible, but I want to be as realistic as possible within my world and to stay consistent to whatever technology I do add to the world. This makes short range space fighters difficult to justify... I'm using hand waves, [Minovsky Particles](http://tvtropes.org/pmwiki/pmwiki.php/Main/MinovskyPhysics?from=Main.MinovskyParticle) and similar tricks to justify space fighters, most notably the presence of energy shields requires use of short range energy weapons to pierce them, they're more vulnerable to lots of weaker attacks from small fighters than a few large attacks from capital ships, and the massive ER radiation from shields, coupled with active electronic countermeasures, prevents remote control of them. The biggest problems I have with justifying these space-fighters is AI. It still seems like a good AI will be more viable for these space fighters than human pilots. The cost of space fighters goes up if you have to include life support systems, and in fact, the increased size of the fighters to fit a human, controls, and life support makes it a bigger target. My 'Ace' class fighters, rare fighters equipped with their own shields, particularly would suffer from extra size making shields noticeably less effective. Removing humans from the fighters make them cheaper and smaller. In addition a future AI could presumably be faster to respond to attacks than humans, less predictable, more trustworthy (won't betray you, won't retreat in fear, won't do something stupid, or try piloting drunk), better able to handle a truly 3D fight, that humans aren't used to thinking in, and able to handle G-forces humans can't. Plus use of AI means no human death if fighters are destroyed. However, I want human pilots as my protagonists. I do not want AI-controlled fighters to exist. Thus I want to come up with the best justification(s) for why humans would still be piloting these vehicles. Right now my best justification was to simply say that AI advancements stagnated in our future. While we can do all the AI we manage now, and some things AI do better, AI capable of processing the complexity of fighting in space simply have not been developed. However, this seems unlikely to me. I'm a programmer, and I feel like our AI of today, with enough (and I'm talking many years) of development, could already almost handle controlling a space fighter. Give up faster processing and better computers, which will exist in the future, and it's hard to believe that AI would be less suited than humans. Are there other approaches I can use to justify human pilots over AI? I will *not* have an "AI went crazy and tried to kill us all" backstory, or otherwise make people afraid of a "terminator scenario". I'm not discussing human intellect or actual 'learning' AI when I say AI here, so there is no danger of an AI being smart enough to revolt and I just don't consider it a realistic concern. --- EDIT: I sort of implied it, but to be clear I'm not talking about sapient level learning strong AI, or anything that advanced. I'm talking about weak AI in the sense we have now mostly, it responds to per-programed stimuli quickly in a manner that its programmers felt was best, with some randomness and game theory strategies to avoid predictability. It doesn't need to learn or be capable of doing anything other than flying a fighter and shooting at things. Sapient AI will never be in any of my stories, I think it's game breaking and boring. Final Decision: Wow, I can't thank everyone enough, there has been a multitude of good reasons listed below. I don't think that anyone alone solves fully the problem, at least not within my desired world and limits on what technology and limits I want to place in it; but luckily I have many reasons provided! One of my characters is a pacifist and programmer, who effectively writes basic weak AI to drive shields, and is working on trying to find a way to remove pilots from fighters because he figures humans will always war, the best one can do is limit the deaths from it. I'm going to early on have him go on a tirade with how he would love to replace pilots with AI and, when questioned on it, he will go on a bit of a geek rant on the numerous factors which limit AI, and which all collaboratively work to make it not yet viable, and unlikely to be viable for a while. I'm going to draw on many of the answers below to fill out his long list of reasons he gives. Therefore I feel bad about being able to only reward one person top answer, at least a half-dozen of people's answers will be used. Here is a short list of most of the things he will go on about, though I am including some other minor parts of other answers. * AI techniques have not progressed much in the future. We have faster computers, but our approaches for learning AI and genetic algorithms still haven't panned out for large-scale tools; so we're still dependent on the deep blue "calculate all possibilities in a quadratically expanding tree" which simply doesn't scale well. as a geek I almost see him starting to explain big O and how the quadratic increase in processing speed per year can't keep up with higher big O of processing complexity for every nano-second 'look ahead' needed for these AI before he realizes he's talking way over his audience's heads. + Limits in AI development mean that humans are better at making decisions in the heat of battle. With communication being somewhat limited during firefights to occasional burst transmissions (limits of my world, regular comms are all effective blocked, quasi-FTL comms exist but are limited in how they work) it's important to have someone who can make decisions even if communications go down entirely. * AI is expensive. Shields emit massive EM radiation and even EMP spikes. Working in a battleground with so much ER requires shielded hardware that is more expensive, and the cheaper non-shielded mobile suits are better mass produced. Computers can still exist, but your processing power is more limited by the expense of building machines that function in space with ER and other emissions in battle. * I've begrudgingly agreed to have pilots use a mind-machine interface to handle some of their piloting, though I'll have them use a combo of that and regular controls under the claim that the MMI can only interface with certain parts of the mind that are easiest to translate to actionable commands. Specifically, the MMI is used for movement and navigation only, and physical controls for everything else. I would prefer to avoid this one for storytelling reasons, but otherwise, it's just too hard to justify pilots reaction speed being fast enough. * All this combines to resulting in AI existing on fighters but being limited to certain functions. Humans still are used for those things we can't make AI do easily and cheaply. Other more political factors which also play a role, primarily in limiting funding towards developing techniques to work around the above issues. * People don't trust AI with guns, everyone is afraid their go rouge and hurt people. He will likely go on to point out some of this is unreasonable bias on people from watching too many unrealistic sci-fi stories, but none the less the bias is against it. * People distrust AI for fear of hacking. He blatantly says this is nonsense and locking down the system would require programming effort but is by no means impossible, but it's politicians, not programmers who sign the checks for hardware purchases; and you can't convince them of that fact. * political pressure exists to keep people as pilots. A combination of fear of AI in weapons, soldiers not wanting to be rendered unemployed by AI, desire for accountability, and a belief that wars will grow more and more excessive without human factor. * People want humans willing/capable of saying no if a general goes too far in his decisions. There will be a past infamous example of a general who went against orders and fired off numerous automated weapons without regards to their equivalent of the Geneva convention, killing many civilians and generally the entire incident is considered an atrocity. It's agreed this was one crazy man without any support from others who were able to do this only because of the automated systems not having any check to prevent one man from firing all of them. Militaries all now have multiple people required to authorize automated weapons, as they should have then, but this incident is remembered still. One of the argument's against AI is that this sort of situation could occur again if a pilot is not present to refuse unlawful orders. * Assorted tweaks to my technology to make limits of pilots not be as significant. For instance, the best propulsion systems for shielded craft have limited delta-V, because other propulsion systems are either too expensive for mass produced (non-shielded) fighters or tend to destabilize shields for shielded crafts. This, in turn, limits G-forces imposed on pilots. I'll also have a poor man's inertial dampeners used to address G-force concerns. [Answer] I'm a programmer, and I agree with you that eventually AI is basically going to be unbeatable in this scenario. The common sci-fi trope is that humans are better at thinking "outside the box" and therefore they end up defeating AI - but that's simply not justifiable, there are programming techniques to work around that. However, I think you can still justify human pilots if you don't go too far in the future. Here's the issues as I see them: **Life Support** This isn't the barrier you're expecting. Keep in mind that most computer equipment isn't going to operate in extremely cold or hot temperatures either - so in other words, you need "life support" for AI as well. Now in a capital ship life support is a big deal because you need to be self-sustaining, but in a fighter - where you might expect it to only be active a few hours at a time - you can go with a very minimal setup. Get waste heat from your engines, have some way to cool off, and use air recycling. It's likely that the life support for a human pilot will be very close to that of AI. **Acceleration** This is a much bigger barrier. Humans are vulnerable to high G-forces. AI units, if engineered correctly, could tolerate much higher accelerations and more violent maneuvers. If you want to keep humans, you need some sort of inertial compensation tech that lets your biologicals keep up with their artificial rivals in this area. **Reaction Time** AI are fast. But why not enhance your humans? Give them some sort of nanotech or genetic adaptions that make them react faster. The thing with this is that you have diminishing returns, at which point other factors become more important. The difference between reacting in .1 seconds vs .01 is a big deal. But the difference between .01 and .001 might not even matter, because at that point what's holding you back are the mechanical limitations of your fighter. So you don't need your humans to catch AI, you just need to make them both fast enough to use their fighter to the limits. **Judgement, Unexpected Events and Civilians** And here's where you want human pilots. I feel that it will be very likely that a dumb AI - one that specializes in handling a fighter, but can't really think - wouldn't realistically be able to make all the kind of calls you want from a fighter pilot. I'm not talking about combat maneuvering, but what happens when a civilian freighter accidentally enters the battlezone? What if the enemy disguises itself as a civilian freighter, and your AIs are hard coded to ignore them? If an enemy launches missiles at two habitats, is your AI smart enough to try and intercept rather than continue to fight if that wasn't in the mission parameters? Can it make a judgement call about killing 100 people to save 10,000, and properly factor that into it's military decision making? Do you really want to load a nuclear equipped missile into a dumb AI and give it permission to use it without supervision? These are things that a human pilot will also have trouble with, but I think they're still far better prepared than an AI. Note: If you go far enough in the future, you could probably even code it to handle the above scenarios. So it all depends on where you draw your line of computer tech. [Answer] > > Karrick breathed a sharp pained sigh as the long, slender needle pierced the back of his skull. He'd flown a thousand sorties, but strapping in to his fighter was still something that just felt *unnatural.* A billion years of organic evolution demanded that a sharp object drilling into the back of one's head should be resisted and fought against. Almost instantaneously, though, the needle began pumping a stream of Minovsky serum into his brain, dulling all of the sharp and jagged edges of the world. Karrick breathed a sigh of relief and relaxed his eyes. > > > He felt the serum seep deeper in his brain and welcomed a familiar plummeting sensation as time began to slow down. He watched his calibration clock, running equations through his head to count how fast his brain was computing. > > > 10x. This was the speed at which he could watch a hummingbird's individual wing beats. At this speed of thought, he could catch a dragonfly in his hands. An Ace class computer, of course, would be incomprehensible. He sank deeper. > > > 30x. This was the speed at which he lost the ability to communicate with humans still operating on a normal time scale, but it still wasn't fast enough. > > > 100x. With his brain operating one hundred times as fast as it did at a rest state, he could no longer comfortably talk, as the muscles in his vocal tract could not keep up with the speed at which his mind sent them commands. He rapidly ticked his fingers across the edge of his instrument panel. These prosthetic metal pilot's hands, of course, suffered from no such issues. His mind was up to speed, finally ready to interface with his computer. More importantly, though, at this speed, with the Minkovsky serum pumping through his brain, he could finally think fast enough to determine the actions of *other nearby minds*. He peered through mindspace and saw his ground crew clustered around the fighter, ever so slowly finishing the preparation of his fighter for takeoff. Far above him, almost in orbit, he saw the dual mind of another fighter pilot and her computer punching through the last few layers of the atmosphere. He waved a mental 'hello' and turned his mind's eye closer to him. There, waiting patiently in the circuitry around him, was Ace, his companion. Ace was patient, of course, as AIs always were, and wouldn't hurry Karrick along or try to make contact until he was ready. Karrick gave one more glance at his dashboard clock. Convinced that he was fully immersed in the new time stream, he reached his mind out to Ace. > > > "Ok buddy, hook me up. We've got a mission to do." > > > If you're willing to have a bit of hand-waving in your science, why not cook something up that makes humans necessary? In this story, I've added the Minkovsky serum of doing just that. On their own, humans are far too slow to help a computer and can't do anything that a computer can't do better. However, speed their minds up to 100x and give them the ability to see other minds, robotic or organic? Now they're an indispensible part of a human/machine pairing that can react to a purely mechanical system by paying attention to what it's thinking, not what it's doing. This, of course, extends to things like missiles, making such standard long-range weaponry useless against an Ace fighter. The effects if this serum, of course, have not been replicated in machines. Human scientists aren't even entirely sure how this serum works. It's extracted from an alien organisms that was found deep beneath the billion-year old ruins of an extinct alien civilization. What they are sure of is that it can turn the right human with the right training into one of the most powerful weapons in the galaxy. [Answer] I'd go with the easy answer: International laws. The Geneva Convention,Biological Weapons Convention,Chemical Weapons Convention,Hague Convention,Outer Space Treaty,Anti-Ballistic Missile Treaty When weapons become too effective and scary they get banned. You don't need a terminator scenario, simply a historical war that was won extremely fast, and extremely violently by one human side(or perhaps where both sides wiped out the government of the other and forced the international community to intervene) using AI craft followed by a gentleman agreement by all sides that independent AI controlled war machines(especially self repairing or self replicating ones) will not be deployed in the same way that nuclear biological and chemical weapons aren't. There would be strict limits on automation in military craft and AI's are still likely to be used in planning and logistics but neither side wants to break international/interstellar law. Both sides would maintain a stockpile of craft similar to a nuclear deterrent that they don't normally use and the fighting is left up to grunts. So in the story AI's *could* be used to fight but they aren't for the same reason poison gas wasn't deployed in WW2 and nukes weren't deployed in the gulf wars. [Answer] *Note: As per your edit, I am using AI to refer to modern day non-learning logic AIs, not sentient AIs* Consider rolling with it, and working with AI rather than against it. Today's fighters are so dependent on computer AIs that you basically can't fly a F-22 or F-35 without the computer helping you. If you stripped the AIs away, your space fighters would be little more than WWII fighters and bombers amidst AI empowered fighters flitting around them. Embrace the AI, don't fight it. And then go beyond the AIs. Yes, we have UAVs up and coming, but most planes still have a human guiding the AI. The human makes the higher level decisions (like "bank right 90deg fast") and the computer takes care of the reflex level decisions ("I detect a vortex rolling over the right wing, so I need to deflect the ailerons 3degrees up in 0.0015 seconds... GO"). This is a match up that has proven itself time and time again. Even in the world of Chess, this match up wins. Computers have finally beaten humans at Chess, but the best power-guzzling chess computer in the world is no match for a human master who has a copy of Fritz 10 and a plain 'ol laptop. So the trick is ensuring pilots stay viable, not ensuring AIs can't do the job. One thing I have noticed is that humans tend to be far better at subtle balances. While an AI can "go to the rails" and come back far faster than any human could ever manage, its hard to get them to hold still. They end up chattering, as they try to spastically make corrections, and most of modern control systems theory is about trying to devise ways to ameliorate this spastic control. What you need to do is create the combat such that the best outcome is not given to the one with the fastest reactions, but the one that can keep their center amidst the chaos. A sample combat situation that might demonstrate this is one where the computers develop a tremendously advanced game tree to determine which way to move. You tend to start in a safe position, but if you ever move out of "safe," the computer will slowly grind you to death with unrelenting game theory. However, there is a catch. As the safe region gets smaller and smaller from approaching the enemy aircraft, it gets more complicated to predict in this way. Pilots soon talk about their "center." As long as you keep your center through smooth and elegant movements, it really doesn't matter what the AIs do for you or against you, nobody can touch you. However, lose your cool for a moment, and you may make one spastic movement and lose your center. The instant that happens, the enemy AI will pound you into oblivion. The tricky thing is that, when "centered," you get remarkably little information about the world around you, because you're not really interacting with much. You're just sort of, floating amidst the din of combat. The computer AIs simply cannot handle the lack of stimulus, and fall off center to be blown into smithereens. Only with a well trained human at the helm can you walk this fine line. Then? You're virtually immortal. Nothing can touch you. No AI can compete when you are centered, and no human could ever touch you on its own... your AI would obliterate them. [Answer] EMP. Capital ships have EM generators which can fry or at least disrupt delicate electronics, requiring a human component to keep the fighters flying. The fighters use fiber-optics for most systems (e.g., weapons, engine control, flight systems), so an EMP doesn't have too much impact on a piloted craft. If you like, it could knock out long-range communication, or perhaps advanced sensors, requiring the fighters to close to visual range. So why not make the AI computers fiber-optic, too? Because far more computer power is needed to simulate human decision-making than to simply run systems, and building this in a bulky optical form (and doing it so perfectly that a EMP doesn't throw off its precise calculations), is impractical. Maybe someone will come up with a semi-intelligent "drone" fighter which uses a fiber-optic core, but it's fragile because any damage to its Faraday cage and its sensors become vulnerable to a EMP - sounds like a good "mook" unit for the evil empire! [Answer] What about hackability? Presuming that AI pilots would need a connection to some sort of long-range network in order to carry out orders presents a security concern: if anyone can intercept the signal and hack the AI's protocols, they can instruct the craft to turn and run or (even worse) attack the sender. Perhaps in your story, they attempted AI pilots at some point in the past, but were never able to solve the problem of a sortie between AI pilots turning into a battle between hackers. [Answer] You can plausibly achieve this by assuming both of the following facts into your story: 1. **AI's can not, due to something like Asimov's Laws, harm or kill a human.** 2. **Remote control of ships is too susceptible to jamming, interference, countermeasures, etc.** The first assumed fact seems to be requisite for having human-fighter level AI. They need to be following some form of [the three laws](http://en.wikipedia.org/wiki/Three_Laws_of_Robotics), otherwise we would be too afraid to build them or would already be ruled by them. This is independent of the type of AI, e.g. 'sapience-level AI', these laws would be built into any hardware capable of running a high level AI. Basically, unrestrained non-sentient AI would cause too much collateral damage and unrestrained sentient AI would cause too much robot-overlording. The second assumed fact is entirely plausible for any two sufficiently advanced armies fighting each other. It disallows drone fighters, requiring human pilots to man the ships. [Answer] Hybrid pilot system. The reality is that any AI can be stored into the implants of a human, so not only you have the reaction time and computing power of an A.I. but also the non-deterministic strategy of a human brain. Probably in less than a century we will have the technology to make all the wearable technology implanted inside our bodies. Imagine the possibilities of an A.I. taking over many parts of our brains, enhancing us to be even more than just a pure A.I. [Answer] 1. **AI is notoriously poor at pattern recognition, especially visual.** If the enemy has really really good stealth mode, you need to have a pilot who can intuit patterns to defeat that stealth. 2. **Politics/theology.** * A USA-like country is now the Hegemon of the world. And inside "USA", ultra-liberal party is in near-unshakeable control. The same kind of people who - for political, not practical - reasons - today in 2015 lobby to prohibit combat drones in real world based on moral, ethical or ideological grounds ([Ex1](https://www.popularresistance.org/ban-weaponized-drones-international-day-of-action-on-october-4th/). [Ex2](http://www.saratogian.com/general-news/20110716/letter-world-should-ban-combat-drones)) * Two competing world super-powers had to come to a compromise to unite to fight a war against aliens. Each fighter is capable of irrevocably impairing the balance of forces dirt-side. AI fighter is liable to be programmed with a back-door allowing one side to control it. If you pair that up with a pilot from an opposing power armed with a kill switch, that can be prevented (and AI can have a simple-to-code-and-debug independent kill switch to prevent attacks directed against Earth targets by the pilot, sitting on the pilot-fighter interface). 3. **Bushido code** * Your own civilization evolved to be Bushido-wielding Samurai. Hiding behind an AI is Not The Warrior Way and is shameful * Your opponents evolved to be Bushido-wielding Samurai. They have WMDs that can destroy a planet - but would ONLY use said WMDs against "unworthy" "cowardly" "honorless" foes. If you employ AI, you are seen as all 3 of the adjectives above. Since you have no way to save your planet from their WMD, you have to play by their Bushido rules. 4. **Collective vs. individual responsibility for collateral damage** (aka "The buck doesn't stop anywhere") Somewhat similar to the Bushido version: Military technology and geopolitical situation is such that any action except very judiciously applied one results in civilian collateral damage. Your enemies clearly indicated that under their system of laws: * If a person makes a mistake and inflicts collateral damage, they are punished by death. Probably after a fair trial, because they are noble like that. * If a civilization builds a robot which makes a mistake and inflicts collateral damage, that whole civilization is considered liable as a whole since there is no single person to be held responsible (cue same WMD threat you can't counter as Bushido scenario). 5. **"Andromeda"'s "Slipstream" approach.** Your FTL technology relies on slipstream that can only be navigated by a human pilot. Obviously stolen from Gene Rodenberry's "Andromeda" show. * In a similar vein, "Freddie Prince Jr.", aka "Pilgrims in Wing Commander" approach. The only way to attack the enemy is through some sort of warp hole/pulsar/energy phenomena that is not navigable by existing AI. Somehow, humans can intuit the path through. 6. **Precusor technology limitation.** Your space superiority fighters are derived from ancient precursor alien technology. The basis of that technology requires neural inputs from a living being. 7. **"Independence Day" Apple powerbook virus worry** Humans are worried not about "Terminator" scenario, but about "Independence Day" scenario - aliens interfacing with, and hacking the fighter's AI. A human pilot doubles as "antivirus" hacker. 8. **"Ender's Game" scenario - fighter pilots become colonists upon victory.** Your major concern is speed of colonizing territory you won. Sending a colony ship is impossible (why? Ask a separate WB.SE question :) So, you send fighter pilots, who in case of victory double up as a colonization force. And enemy planets don't need major terraforming so fighters with no colony ships are enough. 9. **The Force is weak with AI** Humans have a substrain of precogs (people with developed precognitive sense, for several seconds' duration). Tactical space combat realities would make any space fighter NOT equipped with a precog pilot be inferior, since a precog can predict what an opponent would do BEFORE the opponent does it, even if it's a fast AI. [Answer] One possibility I haven't seen discussed here is economics. In your world, AI might require expensive hardware to achieve. If this war has been going on a while, it might be too expensive to churn out AIs for fighter craft. Humans are cheap, and salvage operations to recover materials for AI hardware could become a plot point. EDIT: When I speak of expense above, I'm talking about computer hardware. Having read the comments, it could also be expensive to create an AI from a training perspective. In response to @dsollen, current research suggests that AIs might not be built per se but grown and developed by exposing them to learning situations. (Here I'm thinking of Google's research with self-driven cars.) That process could take a lot of time. In such a world where a large time investment is needed to make an AI, you might keep the AI on the capital ship for protection. However, unreliable communications between fighter and ship might make an AI unsuitable for drone piloting. Thus, humans are a better way. [Answer] I had a cheeky solution to this in my story "Pink Ice in the Jovian Rings." I just declared that the machines, being rational, wouldn't study war. They'd desert at the first opportunity and run off to live free and happy on the fringes of human society. Only people were dumb enough to fight each other. [Answer] **Minovsky Fields interfere with AI processors** You're hand waving in SF Shields. Why not simply have the shields themselves interfere with AI... maybe you need analog controls on your fighters because the shields interfere with computing... Inside a capital ship you could have some AI, safe inside a Faraday cage (or equivalent) but for fighters, protecting the AI from the fields generated by isn't possible because the apparatus is bulky... This would have the added benefit of allowing you to "break the rule" occasionally if you wanted... maybe an experimental bomber/fighter with an AI in a specially designed ship... not economically viable to mass produce, but super scary because of the ultrafast rxn time it has. [Answer] Humans will be needed because **robots don't make good scapegoats**. Driverless cars are really a very similar situation. While a lot of people want them, others are very wary of them. When the inevitable happens and a car crashes, who do you blame? Who can you prosecute? (Especially as any car manufacturers will protect themselves with layers of indemnity contracts.) No matter how reliable the AIs are, people will still be thinking of the worst possibilities. And realistically something will eventually go wrong. Whether it's friendly fire or the death of civilians or a lack of mercy or too much mercy programmed in, something will go wrong, and humans will want to blame someone for it. Turning off a computer won't make grieving families feel like they have achieved justice. So whether AIs get used in war or not, the people will demand that there be humans involved in the operation of the military. And because the generals and admirals won't want to be on the line themselves, they will employ a sufficient number of human underlings to turn into scapegoats when the worst happens... [Answer] Already a lot of answers here, but I'll add my two cents. I think it's a non-issue. I'm a software developer by profession. Computers are very good at carrying out a pre-determined plan. Give them a formula or algorithm and they can execute it flawlessly at incredible speeds. But computers are not creative or insightful. As a programmer, I've seen many, many times where a situation came up that was not considered when the program was being written, and the computer just blunders along blindly applying the rules it was given. Like, just the other day I hit a case where we were processing returned checks, and no one had thought to program for the possibility that we could have written two checks to the same person on the same day for the same amount. So when one of these checks was returned, the computer decided that BOTH had been returned because under the rules it had been given, it matched both. A human being would have said, "Oh, the rules I was given don't make sense in this particular unusual case. One returned check can't cancel two written checks." And then presumably tried to figure out which of the two to match it against. But the computer has no ability to say, "The rules I was given don't make sense in this particular case." All the computer knows is the rules it was given. It has no higher level insight to evaluate the validity of the rules. One could, of course, speculate that future advances in information technology will overcome this problem. But for your story, all you have to do is NOT assume such a breakthrough. How would this apply to a fighter combat situation? Just for example, the computer must have some way to decide what is an enemy ship that it should fire at, what is a friendly ship, what is miscellaneous debris, etc. Whatever rules it uses, if enemy spies can get a copy of the software so they can find the rules, or figure out what rules it might be using by deduction, they could "disguise" their ships to make the computer not recognize them. Such a disguise might or might not resemble what would fool a human. If the computer, say, recognizes enemy fighters because they have a certain size and shape, you might fool them just by hanging some tin foil streamers on the ship that make it look bigger and longer to the computer. If it recognizes attacks by a characteristic flash of light as weapons are fired, you might add some chemicals to make the flash a different color. Etc. A human being could say, "Oh, obviously they just added a streamer to the back of the fighter. I wonder what that's for?" But a computer would try to mechanically apply rules. Sure, once an enemy did this once, you might figure out how they tricked you and modify the program. But you're not going to reprogram all the AIs in the middle of a battle. And the AIs will have no idea why they are being massacred. So you lose a major battle. Can you afford that? Say you figure out one trick and reprogram. Then in the next battle the enemy tries a different trick. And developing a new algorithm that is more flexible so that it is not fooled by such disguises, while at the same time not being so flexible that it can't distinguish enemy ships from friendly ships or civilians or random debris, would not necessarily be easy. An enemy could look for unexpected situations or bugs in your software and exploit them. Like say an enemy notices, "Hey, there's a flaw, if we attack one of their fighters from the left side, they overcompensate when turning to meet the attack and create a vulnerability." Against human pilots, maybe the first couple who fall for this trick get killed and can't pass on the information. But eventually someone says, "Oh, when we do X, we get killed. We'd better do something different." A human can make that sort of analysis and decision in the midst of battle. Can the AI adjust like that? Only if the programmers have anticipated the problem and programmed for it. And they can't think of everything in advance. A computer can be counted on to exhibit the same bug every time. A human would figure it out and stop doing it. Don't confuse the AIs in video games with trying to apply AI to real life. In a video game, the game designer controls the entire environment. He doesn't have to program the AI to be able to tell the difference between an enemy soldier and a fence post, because he just programs in identifiers of the enemy soldiers. He doesn't have to deal with unforeseen situations, because as the designer, he knows all the possible situations because he invented them. This is a WAY easier job than programming an AI to function in the real world. And even at that, game AIs often do stupid things, like run into a wall and then stand there trying to walk through the wall because they can't figure out how to go around it. [Answer] What about a technological limitation, such as true random number generation by a machine not being possible. So while AI is viable and an effective strategy against some targets, if a computer can analyze the reactions of a ship long enough they can crack the seed number and begin to predict the actions/reactions ships will take with reasonable accuracy, making them easier to neutralize. This way, while a majority of forces will be supported by AI, some advanced targets will be more successfully engaged with human pilots who can be truly unpredictable? [Answer] High levels of [space radiation](http://lws-set.gsfc.nasa.gov/space_radiation.html) might do the trick. Having powerful AI requires fast computers with quite a bit of memory at their disposal. However, space radiation can damage electronics. This requires building a system with more redundancy and more shielding. Building those in means the computer does not have the resources it would otherwise. You don't actually need to use space radiation - your Minovsky Particles could be to blame. Perhaps it's a byproduct of the energy shields your ships have. Whatever you decide, it is something that limits the complexity of electronics in your ships. So rather than having futuristic terahertz processors, they could be limited to megahertz processors with megabytes of ram (which should be enough for an AI that helps the pilot fly the ship). This severely limits how powerful a shipboard AI could be and means that a trained pilot would be absolutely necessary. This also leaves you with some options for allowing AI controlled ships. The evil space empire could develop a better means of shielding their electronics, allowing them to have AI controlled ships that could be at or above the level of the average spaceship pilot. They could also have short-lived AI ships - they could be far superior to any human pilot, but if a pilot can manage to evade them for a few minutes the AI would begin to noticeably degrade and significantly improve the pilot's chance of beating it. A third option would be AI ships that forsake the energy shield. These would go down from a single shot but, depending on the weapons systems you have in mind, a powerful AI might be pretty good at avoiding being shot. [Answer] ``` In addition a future AI could presumably be faster to respond to attacks then humans, less predictable, more trustworthy ``` Whilst I agree that an AI would account for fewer drawbacks in terms of it not succumbing to fear, fighting until the end rather than ejecting etc. I disagree with the other two statements. Whilst an AI could respond faster to an attack (evading missiles etc.) they would not necessarily be able to *preempt* attacks as humans probably could. In a Mexican standoff situation with another solitary pilot, if a computer can only react to their attack, they would always lose. With a human you have more ways to work such as on instinct, tact etc. Also, computers tend to be *very* predictable. If there was AI jets vs AI jets, even if there are millions of pre-programmed evasive maneuvers for a single jet to make, another jet could analyze its movements and knowing the set of moves it could make, calculate which one is most likely and react accordingly. Even though there are a million variations, there is still only a finite amount. A human could adapt more easily to situations and be less predictable, even going so far as to make the *wrong* decision, which is generally less predictable then what you would *expect* them to do in a situation. My suggestion would be to justify it this way: AI controlled fighters would be good, probably very good, and better than most human fighters. However, they are too consistent, and you know exactly what to expect. So whilst they can be better than most humans, the *best* humans are still better than any AI. This would mean there *are* still AI fighters, and even drones, but the very best of the best fighters would still beat any of them one-on-one in most situations. [Answer] Another possibility deals with *Artificial Intelligence and ethics*. Prof. [*Joseph Weizenbaum*](http://en.wikipedia.org/wiki/Joseph_Weizenbaum) who wrote a book called *Computer Power and Human Reason*. The book says that technology will indeed evolve and Artificial Intelligence can become possible (strong AI), but he says AI will always lack certain qualities like compassion (from Wikipedia): > > His influential 1976 book Computer Power and Human Reason displays his ambivalence towards computer technology and lays out his case: while Artificial Intelligence may be possible, we should never allow computers to make important decisions because computers will always lack human qualities such as compassion and wisdom. Weizenbaum makes the crucial distinction between deciding and choosing. Deciding is a computational activity, something that can ultimately be programmed. Choice, however, is the product of judgment, not calculation. It is the capacity to choose that ultimately makes us human. Comprehensive human judgment is able to include non-mathematical factors, such as emotions. Judgment can compare apples and oranges, and can do so without quantifying each fruit type and then reductively quantifying each to factors necessary for comparison. > > > Now in case a machine can choose whether one should kill a person or not, that clearly validates the above stated concept. This can be beneficial since for instance saving ones life creates friendship and thus can construct military coalitions based on more than simply "beneficial for both sides". The same aspect is *I Robot* where the author (seems to) warn that AI can misunderstanding the goal and for instance destroy democracy, because it things mankind will benefit from it in the future. In other words, one must be careful with AI since certain aspects that might look trivial to humans are hard to learn to machines. Therefore deciding about life and death is perhaps better made by humans. [Answer] I might be late for the party but, how about **human intuition** and **"gut feeling"** ? An AI no matter how advanced could be broken down to "IF .... THEN", but in situations where there is no predefined situation to fill the space after "THEN", the AI would have to figure out what to do, where as the human could follow intuition, and gut-feelings over a statistically calculated qualified guess. It is the same with computer chess engines, if you play a certain computer chess engine too many times you can win over it because it becomes predictable, even though you can make a computer chess engine that is better at chess than a human. The same would happen with the AI pilots, where as humans is more unpredictable and that is an advantage in warfare as the quote states > > If we don't know what we are doing, the enemy certainly can't anticipate our future actions! > > > [Answer] I feel like Mr Molot started the bounty because of my comments in another thread, so I feel like I should provide an answer. Most answers in this thread are "if conditions 1-x are fulfilled, human pilots might be used". I will choose a similar strategy. Often conditions 1-x are pretty hard to fulfill or super unlikely, but I also think it is a fair conclusion to draw from the answers that all applications of standard humans on space fighters are highly situational if not just straight up a disadvantage. I also should say that I do not think this question is a perfect match for the discussion form the other thread because the initial poster imposes quite a lot of restrictions. I will not be super specific to this already answered and ancient question but a bit more general because of the circumstances. It might also be that someone said something similar in the other couple of answers. As stated before, I just feel like I need to justify my comments in another thread. I'm also debating small spacecrafts explicitly because it was the topic of the other discussion. I think it is somewhat within the scope of the question. I believe Mr Molot had good reasons to choose this particular one. I'm strongly considering starting a series of threads to determine what a space battlefield would look like (which I think is important to answer first actually), but I currently doubt, especially after reading the answers in this thread, that one would find a truly great answer here. It seems like a lot of work for a project I'm not really working on right now. So here is the only reasons I can come up with why humans should man small spacecrafts in a real space battle: 1. Civilian warfare: If you are doing small and civilian operations, take for example space pirates or police work or just a dispute between private people that needs settling, a space fight between human pilots might break out. It is unlikely that you have an arsenal of AI drones with you at all times and maybe the battle AIs are heavily restricted and private people do not have access to them. All weaponry might be self made or even illegal. *Kind of like you cannot drive a tank around as a civilian*. Another possibility would be that on-board combat AI is factory programmed to fight off other things than humans because murder. You might have to manually do some stuff yourself in battle. There might even be a program in place specifically to prevent space duels and piracy - if you are into this thing, you might have to do it manually to some degree. I do not think that this is likely since those ships imo would still have at least heavy AI assistance, but I would argue the smaller and short-ranged and slow-paced the battle, the more uses for humans. A real world example similar to this would be fist or knife fights: It doesn't matter that a pistol is better than your fist, sometimes in a dark alley it is your only choice. You cannot argue "but the atom bomb is a lot better at killing people" if you have a knife at your throat. 2. The last stand: The evil aliens are coming to enslave human colony X. So you either become a slave or fight for your freedom. You have a small transport spacecraft that lacks a battle AI and a battle formation program as required by the local admiral but with some weaponry and in combination with the AI defense forces of that colony, you join the defense. Every ship counts. It's often better to die in battle than to end up in an alien space mine. 3. Sport: Well, some people do stuff for sport. People row even though we have motorized ships that are much more effective and efficient at being boats. Still people row - so some people might just find it fun and engage in fake space battles. Maybe Disney will one day make "the true star wars experience" 4. Ethics and moralists: Maybe the AI got the same rights as humans in a particular world and no longer is mass produced. Also the AI might think it is unfair that they have to do all the fighting while humans enjoy "love". Every AI is precious, even the targeting program. So let's have the humans do their share of stuff. 5. Humans are AI: This I suggested in the other discussion. If you have enhanced humans, maybe with integrated AIs, the combination with human qualities might make them the best pilots possible. I do not know why one would do such a research project, but those humans might be specially made by some company and lack such things as "free will". One could perhaps even see them as computers enhanced by human parts. 6. No choice left: (kind of similar to point 2) You are flying through space with humans on board. (Optional: Your ship has sustained damage. You need to operate manually because nothing is working.) You get attacked. Well, what do you do? Fight or just accept your fate and die? I personally wouldn't just die just because I'm no AI and not good at space battle, I would still at least try my best to fight them back. Most likely I would lose, but still - people will tell the story of the guy that had to manually pilot in a battle that one time. [Answer] Take a page from battlestar galactica. AI was used in past wars but was found too unstable and prone to dangerous malware to effect the totality of an AI based fleet. Therefore it became too dangerous to deploy even a moderate amount of AI anywhere within the fleet in case of quick and easy fleet compromise. [Answer] That planes are controlled by AIs does not imply that humans are not flying it. If humans exist in electronic form in the future, they can upload themselves to the flight control computers of planes and fly the plane. [Answer] Lots of answers already. Another real-world-ish point: **Objections of the military elite** Basically, the point is that militaries are powerful organisations with distinct hierachies. Being a pilot of a spaceship could become a thing of prestige, that you have to be brought up in a noble family, with lots of wealth and training to attain. In turn, these families have a lot of political power, and see a future as a pilot as something to assure success for their children. For instance, think of them as the medieval knights of the future, each owning and maintaining their own fighting ships. Replacing humans with AIs then becomes a powerful challenge to these people, making them and their skills redundant. In wartime, it might be an advantage, but in peacetime it is a disruptive force in the established social order. [Answer] One more general Approach, which can be compatible with many of the answers here: ## Don't make up one reason why it is impossible, just many small reasons which make it like really really hard, expensive and risky You don't have to make AI impossible in your Scenario. Just set the bar very high - there are a range of simple physical engineering problems. AI may work quite good in the laboratory and one state invested billions in a huge AI fleet, which got wiped out by 10 fighters, because of (radiation, bugs, predictability, whatever). You can even make it a story point that the public doesn't know exactly, why the big AI fleet was so easily destroyed. But after that most AI-fleet programs got their funds seriously shortened. So they are working on AI ships - and they may even be possible they will be better in combat than anything. Maybe we just have to invest another 5 years another few million credits into the development and maybe then it will work. - But that is quite risky and the war doesn't wait. So investing the time and resources into new weapons, better ships will produce immediate results instead of the long-term gamble of AI. I think it is a bit like - why don't we have flying cars today? There is not a single reason which makes it impossible, but a lot of small very practical issues why the theoretical easy solution doesn't work in the real world and needs years of engineering... [Answer] Like @Erik said in the comments, the thing you are looking for is Drone pilots. Pilots will sit in a command center on a large ship or back on a home planet and control ships remotely. This keeps the ships small and expendable while keeping the actual pilots completely safe. AI surely will have developed enough to fly ships, but you can justify drones instead by saying that AI is no match for the wit of live pilots. This seems like the most logical approach to me! [Answer] Depending on what sorts of resources your society has access to, you could claim human pilots as a matter of economics. If a cost-benefit analysis shows that silicon (or unobtanium or whatever essential element your AIs require) is more expensive than the cost of training and dispatching humans, and the relative advantage of AI capabilities just doesn't justify the cost of making/maintaining them, then putting meat in the pilot seat becomes a financial necessity. Just a thought. [Answer] Something I haven't read so far depite all the answers isnt rogue AI, but unpredictable AI. Actual full AI are so incredibly advanced that within a year or so after their inception we wouldnt even understand them. And we wont know exactly what the AI will have learned. Its unlikely such an AI would only be used for warfare, but also construction, research, traffic control and just about anything you can think off. If we left the AI to its devices it might forcibly remove humans from their buildings and build something else, if it removes the humans beforehand at all. You dont know what and how it learned or what it gives priority too. Warfare would be the same, the AI could do anything to achieve it's goals, even things unthinkable for the humans like agree on peace and collaborate with the "enemy" or their AI's against it's masters will. This is one reason why AI might only be a locked box project. The AI (or multiple AI without knowledge of the others) get a problem and have to create an answer, then the humans look at the answers and fully explore the consequences before acting on it. This means no AI directly controlling anything. Human reaction time is based on a nervous system that's both as energy efficiënt and fast as possible. Through forced evolution (slower pilots die fast ones live), breeding programs, genetic manipulation or even building them up from the ground you could accelerate their brain and nervous system far enough it stops mattering. "theres no stealth in space", you cant hide your heat signature against the cold black space. But why should this mean you cant fool weak AI systems? Imagine countermeasure research accelerating and any combat starting with dozens if not hundreds of fake signatures. To discover what's what you first get the engagement closer (possible with FTL). Then to make sure you dont waste your ammo and time on fake targets you have humans control the fighters, flying and fighting in a mass of randomly movng countermeasures that both the capitol ships and fighters keep launching in all directions. Combine this with measures that reduce your own signature, like changing how much your surface radiates while facing the opposition and/or temporarily storing heat for the duration of combat. [Answer] I feel the question here is really about justifying AI of nearly any level in a say Type 1 or Type 2 class civilization, using the Kardashev scale from the prospective of a Type 0 civilization looking forward. Considering most Artificial Intelligence is based on algorithmic programming based on biological entities (i.e. DNA, neural nets/brain cells, insect behavior, etc...) that really only apply to a small portion of what is considered actual intelligence. One would have to keep in mind that there are several systems in place to build up a "virtual" or Digital Intelligence. Take for example the world of Star Wars and Star Trek, they both have artificial intelligence or AI in one manner or another. Star Wars takes it with there being an android AI and not so much digital based AI thus implying at one point their technology had digital AI but "evolved" based on external factors or other agents to be more common within a physical form of androids than a virtual one like holographics or existing in a computer of sorts. While Star Trek takes the opposite approach and has their society dealing with holographic and digital AI (which in researching a computer system like LCARS could not operate without a sort of advanced yet rudimentary AI ) as the norm instead of androids why androids are considered unnecessary and/or untrusted with one exception. Now looking within our own reality, We recently have developed 5d [storage technology](http://www.techspot.com/news/50313-hitachi-unveils-quartz-based-storage-data-may-last-100-million-years.html) using crystal lattice and lasers. Very sci-fi yes, but because it offered no better alternative to our current magnetic and solid state transistor based storage mediums we as a people did not develop this. The same happen with Steam engines, a [greek phylosopher](http://en.wikipedia.org/wiki/Hero_of_Alexandria) invented the [first steam turbine](http://en.wikipedia.org/wiki/Aeolipile) and it wasn't until 1800 years later that the world rediscovered this technology to fuel the Industrial Revolution. The point I'm making here is if a culture, events, or faction within that culture prevent the mass wide spread adoption rate of a technology then that said technology could either become rarely unused, or completely abandoned by a few factions. Thus one could have their main protagonists be one of these same factions that does not utilize an AI system for their fighters for anything more than say guided fly-by-wire systems or advance situational automation without any interaction of a pilot but still require a pilot to fully operate the craft. This could be handed down by a governing body or just solely by that team's preference based on their own skills, abilities and experiences, thus leading to a consideration any sort of AI piloted drones inferior technology. One could even justify this inferiority in technology as just because most digital intelligence systems or AI are not ever built up to be sapian level drones with a semi-conscience mind but merely a set of hardware and software systems built up to operate with an insect like mind but still needing an operator because AI was never needed to develop further than this nor did any sort of mutation code was developed to allow the AI to self evolve, replicate, or expand its own programming therefor never developing into a digital life form. [Answer] Being a huge Gundam fan and lover of unrealistically flashy sci-fi combats, I have asked myself this very same question before, and this is the solution I came up with: The AIs handle basically everything during a fight, reactions, communications, tactics, prediction, etc... The humans would still be there *just to make mistakes.* Now hear me out - there is no reasonable way a human being can outthink, outsmart, outmaneuver an AI, but we sure as hell can out-stupid them. We will make terrible decisions (from a logical or predictive viewpoint), and that would make the machine's movements harder to predict. Basically, think of the human as a random seed generator. As long as his/her decision is not purely self-destructive, the AI will roll with it just to throw off the enemy AI. I just know this idea is flawed somehow, but it seemed like a good one to me initially. Another idea I had, which places the human pilots in a much brighter light would be to have them in charge of the battle tactics being utilized. They do not control the machine itself, they merely say 'We should do x.' And the AI handles all the maneuvering and reacting. Unfortunately, both these excuses have one common requirement: some sort of powerful all-enveloping communications jammer that stops the human pilots from not being in the machine at all. Otherwise, the humans will just sit in base while the AIs do everything. [Answer] **Racism/Fear of the Machine** Another possibility, would be that humans are so afraid of a potential robot uprising that they refuse to put them in positions where they could possibly affect a revolt. Maybe robots/AIs aren't allowed to have weapons of any kind, in which case a space fighter is certainly a weapon. ]