Datasets:

LLukas22

/

lfqa_preprocessed

like 0

When I see gray, what wavelengths am I seeing?

Many times the color grey is generated by a mixture of compounds. Some which absorb and some which reflect. For instance if you mix white paint with black paint you will end up with a grey color because the mixture contains compounds which reflect all light and compounds which absorb all light. So at any given point in the mixture you would expect to have both compounds and depending on which compound the light hits determines if it is reflected or absorbed. You can also have large molecules with multiple groups some of which absorb multiple wavelengths of light while other parts of the molecule reflect.

how do people get hd clips from tv to the internet?

A PC with a "Capture Card" of one kind or another. HD material from a cable/satellite box gets fed into the computer, where it's "captured", and can then be edited and uploaded. It's not legal, but it is rather easy with modern software.

Are there any animals whose blood is not red?

Yes, but it's not particularly common. A common example is the [horseshoe crab](_URL_0_), which has hemocyanin in place of hemoglobin. Vertebrate blood's red color comes largely from hemoglobin, which is bright red when oxygenated and a darker red when deoxygenated. Hemocyanin is blue when oxygenated and colorless when deoxygenated, so horseshoe crab blood is generally described as blue. Hemocyanin is also used by molluscs (like some snails) and other arthropods (like some spiders).

degrees of education

Associate's Degree: 2 years Bachelor's Degree: 4 years Master's Degree: Bachelor's + 2 years Doctoral/Ph.D: Bachelor's + 4-6 years.

why has easter turned into a time to celebrate finding chocolate/eggs from a bunny?

You might ask why did Easter turned into a Christian holiday "celebrating" the torture and death of their god when it is actually (and originally) about the Spring Equinox and fertility.

Why we're African slaves not more common in the uk?

There was a legal question regarding whether or not the state of enslavement could exist on British soil. The situation was ambiguous, and certain West Indian plantation owners did bring slaves back to Britain with them, as personal valets/maids and the like. However, it became increasingly common, as the 18th century progressed, for enslaved persons to bring a legal challenge against their 'owners' in the courts, to claim their freedom and avoid being sent back to the harshness of plantation life. The earliest such case was in 1690. Judgements varied - there are cases of enslaved persons being granted their liberty, sometimes permanently and sometimes temporarily; as well as cases where the state of enslavement was confirmed rather than overturned. The most high-profile case of this type was that of James Somersett, a slave 'owned' by a Boston government official, with whom he travelled to Britain. (This is at a point where the US is still a British colony, just about). Somersett escaped, but was recaptured and sent aboard a ship bound for Jamaica. A suit for his release was brought by abolitionist campaigners, and after a lengthy deliberation, the judge Lord Mansfield determined that Somersett had the right not to be forcibly removed from the country against his will. Crucially, he did not rule that slavery on British soil was illegal, but it was interpreted this way by many slaves and masters alike. So, in short, the number of enslaved black people in the UK was always tiny, due largely to the fact that their ambiguous legal status there meant that their 'owners' risked losing their slaves via legal mechanism. There was a small community of free black people in 18th century Britain, primarily of former slaves who had been granted freedom - the writer Olaudah Equiano was one, as were Francis Barber (the servant and heir of the writer Samuel Johnson), and Ignatius Sancho. It's estimated that there were around 15,000 black people living in London by the end of the 18th century, although these numbers are difficult to fully reconstruct because racial identity is not always recorded in datasets such as parish registers.

Does a satellite experience centrifugal force or centripetal force?

It depends on your frame of reference. In an inertial frame stationary with respect to the Earth, the satellite is only subject to a centripetal force (gravity). In a reference frame co-rotating with the satellite, the centripetal force is still there, and there is additionally a centrifugal force equal and opposite to the centripetal force.

how was the internet made? like how did they discover coding, etc?

Computers predate the internet by several decades, but the origins of the internet can be traced back to a US Military project in the 1960's called Arpanet. They wanted to see if they could get computers to communicate with each other. The first data packet was sent from a computer at UCLA to one at Stanford in 1969. The technology that came out of Arpanet ultimately led to the commercial internet.

Does boiling the same tap water multiple times change anything in it?

Boiling water multiple times reduces the dissolved oxygen and any other dissolved gases, as the solubility for these decreases with temperature. No new minerals are added or dissolved upon multiple boils - whatever minerals come out of your tap are mostly unchanged during the events you describe, but one major chemical change is that water treated with chlorine will allow chlorine to evaporate. However, many municipalities use chloramine, which does not evaporate. I don't think any of this will have a significant effect of the solubility for your tea, so the brewing process would be identical in all cases.

Russian Drug Epidemic - Krokodil - Causes Necrosis. Is there any way that this can be healed? [Medicine] [NSFL]

Let me clear my throat a little and thank you for the warnings. These people have packed on every kind of cellular stress imaginable. They are throwing acids, aromatic reactive species, most likely heavy metals, and who knows what else, *directly* into their circulatory system. Now, let's stop and talk a little bit about the circulatory system: Your circulatory system perfuses all your tissues (anywhere your tissues are, your circulatory system is too). It is the expert nutrient delivery system and waste removal system. That is, under normal circumstances, as in when you don't have an addiction to zombie cosplay. As with any drug addict that injects, they are hijacking that system in order to efficiently and effectively administer and feel their drug. Now, with that preamble, let's start tackling your questions: **Why does this drug cause severe necrosis?** First of all, this is not just a drug, this is a cocktail of chemicals created with a cave man's sense of precision. Based off the io9 article's description of a couple of the chemicals, I took the liberty of referencing the Material Safety Data Sheets for each. [Iodine](_URL_2_) is corrosive and can cause chronic health issues with the thyroid gland and possibly many other organs. [Gasoline](_URL_0_) doesn't have many immediate effects but contains benzene which is a known carcinogen. [Red Phosphorous](_URL_1_) is an irritant and does not have known chronic effects.[Hydrochloric Acid or HCl](_URL_3_) is tricky because they probably aren't preparing exactly the same molarity every time and so we cannot easily assess the severity of the consequences of injecting it. I should add that on the first page in bold letters it says "POISON! DANGER! CORROSIVE!" These all have a fairly low Lethal Dose for Rats. In fact, none of these MSDS's indicate the toxicology of intravenous exposure to these chemicals let alone as a mixture, but the chronic effect of all of them together is evident. My guess is that chronic inflammation, DNA mutations (resulting from prolonged carcinogen exposure), and oxidative stress triggers massive hemorrhaging, widespread inflammation, and apoptosis (cell suicide) radiating from the initial site of injection, but also appearing in random locations throughout the body (because of the nature of exposure), including more often the feet and arms. In short, necrosis in krokodil users is a result of intravenous exposure to a menagerie of chemicals, that are toxic in a variety of ways, for an extended period of time. **Could this possibly be healed/reversed after it happens?** After what happens? This is a progressive necrosis of the tissue through chronic exposure to chemicals. The ability to ameliorate the effects are entirely dependent on the progression of the disease. More often than not, amputation will be required, but many will have damaged their internal organs as well. Remember that the cardiovascular system perfuses every tissue. The first systems damaged will most likely be the liver and kidneys. Tough organs to fix without altogether replacing. More importantly, there is the physical and psychological addiction of Desomorphine to remember. You don't want to waste time trying to treat a patient with a replacement organ that could be used on someone that needs it more and will keep it healthier. Moreover, why enter the user into some expensive new therapy that can heal the self-inflicted wounds at the expense of the government's (tax payer's) Rubles when he is going to begin the process again. As a stem cell biologist, my unethical side would suggest using these patients in experimental cell replacement therapies since they are doomed to die anyway. My ethical side says that many of these people should just be put to death quickly so they don't have to endure the mindless rat race of literally rotting to death just to get a useless high. **What are the medical repercussions?** I think we have answered that by now. Loss of Limbs, extensive damage to internal organs, including but not limited to the kidney and liver. **If amputation is necessary *what exactly are they doing in the youtube video/why*?** I'm not entirely sure, but I'm guessing the patient did not go to a high-level care facility to be treated. They are using a wire saw to cut through the exposed fibula and tibia to remove the necrotic tissue. The tissue appears to be soaked, probably in disinfectant. This is to prevent the spread of infection. I'll be frank, this is really shitty to talk about man. I hope I answered your questions. You are obligated to answer one of mine. Why are you so curious about this?

What did people in the 'Old West' name their pets?

I'm honestly more curious about horse names

How did Italians preserve the tomatos needed for many of their dishes, prior to the invention of canning?

Sorry, other poster is dead wrong, tomatoes were eaten fresh only rarely before the invention of commercial canning, getting down on fresh tomatoes is a pretty modern thing, your pre-canning tomato breeds would not make for tasty fresh eating, pretty acidic. But they were certainly preserved, it's a smart question you've asked! What they did was make a paste of tomatoes, called conserva. [I have previously written here about how they made (and make!) conserva,](_URL_0_) including a video! However, in the era of conserva (and in Italy today, depending on region of course) tomatoes were a minor vegetable. For a little on how the tomato came to be seen as #1 Most Italian Food, [read here.](_URL_1_) (Despite it not being my specialità at all, I've apparently made myself a little side career in tomato history here, because people ask about it so often!)

why does the burn of putting your leg in hot water seem to come a second or so after it’s been pulled out?

So there’s ‘two’ nervous systems that usually work together. This is an example of where one takes over first. - CNS = Brain. It controls the actions you think about so it takes longer to work. - PNS = No Brain. Controls reflex actions, ones you don’t have to think about, so it’s faster. The leg in hot water reaction would work something like this: 1. Leg goes into water 2. PNS realises you are in danger. 3. PNS moves leg out of the water because it knows you’re in danger. 4. CNS realises leg is out of water 5. CNS realises leg is in pain and lets the brain know, meaning you only then feel pain. I hope that’s simple enough, ask any questions if you need clarification.

Why don’t everyday movements cause sub-concussive impacts?

This is counterintuitive, but if the density of the egg in your example is roughly the same as the density of the fluid (so that it can float in it) then shaking the jar wouldn't make it bounce, it would keep floating roughly in the middle no matter what you do. Sudden acceleration only causes problems proportional to differences in density, causing different parts of the system to experience different forces corresponding to that acceleration, so that difference becomes a force between components and can cause deformation. If the density is roughly the same (and the stuff is mostly incompressible) then nothing much happens in response to small accelerations.

why are commercials so bad? why dont companies hire comedians or any other kind of professional to create commercials for them?

Cost. Using big stars or producers is expensive, add on the cost of the time slot for the commercial and it cuts into company money. The smaller the business, the lower quality production

What exactly are virtual particles? For example, a Weyl Fermion is apparently exciting for semiconductor applications, but what properties does it have that make it so?

Virtual particles appear in perturbative field theory. When calculating observables in a field theory, it is almost always impossible to solve the problem exactly, so you develop a method to compute things approximately (this is called perturbation theory). The most useful way to do this is to introduce Feynman diagrams - it turns out that every term you need to calculate can be represented by a picture which looks like some process occurring, so all you need to do is write down all possible pictures and translate the pictures into math (much easier than deriving the exact terms from scratch every time). In these pictures, one has lines which represent (or maybe just "look like") particles which violate the equation E^2 = (pc)^2 + (mc^(2))^(2); we call these "virtual particles." They only appear when doing this particular approximation. Virtual particles are never detected in real life, and they never appear in cases where you can do exact calculations, but they are useful mnemonics to use when discussing a calculation to a fellow physicist. I wouldn't describe them as ever "coming into existence;" they're just a tool which comes from a very specific type of calculation, and don't necessarily correspond to anything physical. I recommend [Matt Strassler's writeup on virtual particles](_URL_2_) if you want more info re: virtual particles. > For example, a Weyl Fermion is apparently exciting for semiconductor applications, but what properties does it have that make it so? I think there's a confusion here. The Weyl fermions which have been of interest in recent condensed matter physics are **not** virtual particles; they are [quasiparticles](_URL_0_). Quasiparticles are a kind of collective excitation which occurs as an aggregate excitation of many degrees of freedom. Basically, when you have an enormous amount of electrons interacting, the low-energy excitations which are made up of many electrons may look nothing like an electron, but rather like something totally different. Especially in the last ~30 years or so, we've found systems whose quasiparticles with extremely exotic properties, such as quasiparticles which are neither fermions nor bosons, or quasiparticles with fractional charge. Recently, people have found that Weyl fermions can be realized in condensed matter applications ([theoretic review](_URL_1_), plus [experiments](_URL_3_)). Weyl fermions are massless particles which obey fermionic statistics. The interesting thing about their recent realization in condensed matter is that they remain massless under any sort of perturbation in the system, and the way in which they arise and their mass is protected is very interesting (it'd be hard to elaborate in this post without either getting technical or by making it twice as long). I can't really speak to applications - it's really fundamental research. We've only barely found that this sort of object exists, let alone found ways in which it can be engineered for a real purpose. (Weyl fermions also appear in particle physics, though the realizations are rather different from the recent condensed matter one).

why is the water contained in a source like soda any less beneficial?

Soda is > 90% water (probably 98% or so). If you want to drink 8 glasses of water a day, 8 sodas would do it but the sugar and sodium would be terrible for you're health. Someone who says they don't drink any water, just soda, or that drinking soda doesn't count as water has no idea what they're talking about. It would be like saying you're not eating beef if you eat a hamburger.

how are some mods in gaming compatible to new game versions while other mods need to be updated? (eg. skyrim - compatible after patch but minecraft - mods need updates)

It depends on what those mods were doing to the game files, and what was changed in those files between versions. For example, if you alter the "running speed" value in the movement script, it's not likely the company is going to change the way movement works between versions, so your mod will still work. For a counter example, if you use a mesh or model reference, or change a script for object physics, when the new version is released with updated models and textures, or new things that use/affect the physics script, you're going to need to change your mod. If you don't, you may end up with any assortment of bugs: * invalid texture/models, and so your stuff just doesn't show up (animations don't work, invisible objects, clipping through things, etc) * your mod to the physics script breaking (your fireball now throws upwards. not where the camera is looking) * your mod breaking the new changes to physics (walking off a ledge on a horse results in their flying)

Why do specific laws apply to the universe?

Physicists are much better at answering 'how' than why. E.g: "How do magnets work?" "How does gravity work?" Why is a much more philosophical question and is, in a sense, much less defined (and therefore less interesting :P) than actually learning *how* things work.

what exactly happens to your skin when it reacts to posion ivy?

It's called a type IV hypersensitivity reaction, more commonly known as an allergic reaction. This is a special type of allergic reaction that is not caused by histamine like most allergies are. This type of reaction is due to T cells attacking your own cells because they have an antigen (poison ivy) in them and your immune system thinks that it's a virus or bacteria. The end result is that your immune system ends up attacking your own cells, which activates the inflammatory response, which is what causes the redness and itchiness. One thing to note is that you need to be sensitized in order to have this type of reaction. That means that you brushed against some poison ivy at some other time and that "activated" your immune response. Since it has now been activated, the next time you come in contact with poison ivy, you will get the associated dermatitis. Edit: Sorry, I forgot to mention this. Cortisone should help with the itchiness and inflammation. Antihistamines won't do shit.

What makes some cancer "inoperable"?

Sometimes the cancer can occur in places where it would otherwise kill the patient. Like a tumor deep inside the brain might require a surgeon to do too much damage getting it out, or risk breaking up the tumor and causing it to spread in the body (the cancer cells can take up residence in other places, including the wound channel on the way out). With something like lung cancer, the cancer might just be spread in too much delicate tissue (lung tissue is very volumous; they say that you have like a tennis court of area in your lungs), and they wouldn't be able to just cut it out without damaging too much tissue or destroying the organ.

resting membrane potential. why it hyper/hypopolarizes?

The potassium and sodium ion concentrations are what cause the neuron to fire. Or actually they allow the action potential to propagate along the nerve. A nerve cell starts off polarized,meaning the outside of the membrane is positively charged and the inside is negatively charged. the outside contains excess sodium ions the inside excess potassium ions. For the action potential to propagate a stimulus reaches the neuron, which opens gated ion channels allowing sodium ions to rush in which start the depolarization of the neuron. At a certain point the depolarization becomes an unstoppable wave as the gated ion channels all along the neuron open and sodium rushes in. this is the threshold potential. The neuron is completely depolarized and the signal transmitted. After the cell is depolarized gated ion channels on the inside open and allow potassium ions to flow out. Restoring the polarization but now by a different ion balance. At a point more potassium ions are on the outside than sodium ions on the inside and the gated ion channels close.This causes the membrane potential to drop below resting potential and is said to be hyperpolarized. During the following refractory period ion pumps restore the original ion balance and the nerve cell can't transmit during this period.

How fast was the decline of civilisation in Europe (including Britain) after the fall of the Roman empire?

This is a difficult question to answer, due to the size of the empire and how different regions reacted differently to the decline of Roman authority, but generally I would say that though decline was visible in the West, it was a gradual one. In the Eastern Mediterranean, not much has changed at all - Egypt was as prosperous as ever, fringe areas such as the Negev desert or the Limestone Massifs in Syria were still densely populated and cities continued to grow in size. In the East, the economy and the empire were as vigorous as ever. Even in the West, things weren't so grim. Vandal Africa for instance was still very productive and Chris Wickham has suggested that Roman taxation system didn't collapse there because they were reverting to a more 'barbarian' form of rule, it was because the Vandal elites were getting so rich from confiscated estates that they didn't need the Roman taxation system any more. There is plenty of evidence that the West declined in material terms of course, with Bryan Ward-Perkins' book *The Fall of Rome and the End of Civilization* being a very accessible overview of the archaeological evidence - tiled roofs, which were available to all Romans, even the poorest peasants, disappeared when Roman rule disappeared, and more generally, expensive and complex pottery became rarer and can only be found in a few ports in the Western Mediterranean, rather than widespread as before. Britain in particularly declined significantly, as it was a fringe province anyway - things such as patterned mosaics (a very Roman form of decoration) generally arrived a century after they reached Gaul, a much more Romanised province. When Roman authority disappeared, the integrated trade networks connecting cities and provinces faded away too, as there was no centralised bureaucracy overseeing the distribution of goods or friendly armies protecting the means of exchange. Instead, locals had to make do with local goods, with only the elite still capable of procuring luxury goods abroad. However, though there was a decline in material prosperity, there wasn't a collapse of civilisation. People liked the things they had, and even if there was no longer an emperor ruling over them, they wouldn't abandon the things they were used to. The 'barbarian' Franks, Visigoths, Ostrogoths and Vandals that took over the western provinces of the empire were all used to the Roman way of life, and they didn't want to lose all its advantages either. Above all, there was still a Roman Empire for them to look up to - the emperor in Constantinople was still an awe-inspiring figure and we have letters from Francia and Ostrogothic Italy all clamouring for titles and recognition from the East. Rome was very much alive after 476 and post-Roman warlords recognised that. They all made an effort to keep in place local elites, such as local senators and bishops, to secure their rule. These tribes were never the majority in any given province and they needed to placate the local Romanised population. In Italy for instance the Senate still met, the Romans manned the bureaucracy and education was kept at a high standard. The same was less true in Francia and Visigothic Spain, due to warfare and the less integrated economy they had, but the decline in Roman institutions was slow and generally unwanted, since Roman institutions and luxury goods were good things that leaders didn't want to destroy. Let me know if you have any more questions :)

do people in other countries have the same view of the moon that i do if we look at it at the same time?

Because the moon is tidally locked (the sun only shines on one side at any given time), only one side of the moon is illuminated. This is why we had to send spacecraft to the far side of the moon to see what it looked like. In other countries, the moon may be in a different position in the sky due to its position on Earth, and because of the angle the moon may seem to look different, but the part of the moon you can SEE (as in the part that is bright) is the same.

why is it now 4k and 8k instead of 2160p and 4320p

Well, for one thing, it's easier to say, and easier to remember. But I believe the real reason is that using the horizontal pixel count a more consistent number to use over vertical, since number of vertical pixels changes according to the aspect ratio of a movie, e.g. 1.78:1, 1.85, 2.35:1, etc all have a different height in pixels. yet the same 4K of horizontal resolution. Indeed, this is what they use in digital theaters now; 2K, 4K, 8K. In the days of old, that didn't matter - everything was 4x3 or 16x9, and movie's original aspect ratios were an afterthought. But we've moved more and more towards home theaters and watching movies, it just makes sense to normalize the terminology with what they use in the cinema world.

What would have Mary called her son?

Jesus is his name as passed through a number of transitions through other languages. The original Hebrew or Aramaic name would be something like Yoshua. Some modern groups make a big deal of calling Jesus by his "real" name. Earlier centuries didn't worry about that though. It was common for names of biblical figures, foreign royalty, etc to be changed into a fitting form in your own language. Mary wouldn't be Mary either, but more like Maryam, with the "a" as in "hard". Medieval kings were known by many different names: Charles would also be Karl, Carlos, Karel... the view that there is exactly one version of a name that is the proper name is a rather modern idea.

why don't artists just release their entire album as singles to increase chart performance and song sales?

A lot of artists produce songs which are meant to be listened together and in sequence as they enhance and compliment one another. If they were sold individually and listened to individually they would sound a lot worse because the artist would have failed to create an atmosphere needed to enjoy some of their works. Something that goes along with this is, people tend to ignore a lot of songs released by artists because they're not considered hits, they may not necessarily be bad, but as mentioned above they don't stand well on their own.

what is the physiology behind being gay, lesbian, bisexual, transgender?

We're not really clear on it yet. There's some studies that suggest that transgendered people have brains that are physically closer to that of the sex they identify as, and some theories about hormone differences while in utero altering brain chemistry, but there's no real concrete answers yet.

How were the craters on the side of the moon facing earth created?

[Here are Earth and Moon, to scale](_URL_0_) Does that answer the question?

what type of data is obtained from underground nuclear tests?

The main purpose of a test is find out whether the device can be safely armed and successfully detonated. The tests are performed underground for environmental and safety purposes, but can make taking precise measurements difficult. If buried at an adequate depth, yields can be roughly estimated based on the size of the melt crater. Other data includes shockwave propagation rates, measured using pulse reflection. This has been used in the past to identify and correct early shell ablation, among other timing issues. Toxic byproducts and radiation are also a point of interest. The timings and magnitude of seismic and air waves, along with radiation, can be used to pinpoint the source of slow reactions and incomplete yields

How dense does air get in the compressor of a jet engine?

For an isentropic (idealized) compressor, the density change is equal to the pressure change raised to the power of 1/gamma (1/1.4 for air). So a (high end) compressor ratio of 40:1 will give a density ratio of 14:1. At sea level, you're looking at 1.2 kg/m^3 ambient density, so it'd be compressed to ~17 kg/m^3. Less than half that at cruising altitude. I wouldn't really characterize that as "incredibly dense". That's about 1 pound per cubic foot.

Why did the Romans have so much trouble with the Germanic tribes?

I wouldn't say I'm an expert on the Germanic tribes, but having read fairly extensively on Caesar, Varus and Germanicus, I can give you some background. The Romans actually did a pretty good job of whipping German butt. At the end of the first century BCE, Tiberius (soon to be emperor) and his legates had done a damn fine job extending Roman borders East of the Rhine and North of the Danube rivers. So much so, they declared the tribes there pacified. Tiberius peaced out to go and deal with an Illyran revolt and Varus, a former governor of Africa and Syria was appointed to watch over these lands with three legions (soon to be extremely infamous legions). Enter Arminius, a commander of auxiliary German forces during the roman subjugation, a roman citizen AND a Germanic Prince of the recently subdued Cherusi? tribe. He was a sneaky fucker. Playing off Varus' lust for political glory and his own ambition to unite the German tribes, Arminius convinced Varus to march north with his legions to proactively subdue a rebellion (which he was organising). Varus being impetuous and also extremely trusting of Arminius (they had been bros for ages), rallied his troops. The legions were the 17th, 18th and 19th and took off toward modern day Mainz to expand the borders further and expand Varus' political penis. What followed was the greatest ass kicking the Romans would receive since Cannae... The Battle of the Teutoburg Forest. Led down a narrow trail, which according to Cassius Dio, had been ravaged by storms, the Romans were ambushed. Unable to properly form up and completely cut off from a retreat, the three legions were harassed and slaughtered all day and night as they made a cannonball run down the trail in a doomed attempt to punch free of the hell they found themselves in. I get chills thinking about how horrifying that experience would've been. Some estimates put the Roman losses at 6000 to 1, but these figures are highly disputed... though they do give you an idea of how utterly obliterated they were getting. The 17th, 18th and 19th standards were lost. Rome was shamed. Apparently Augustus never lived it down and was often found mourning the lost up until the day he died. "QUINTILIUS VARUS! GIVE ME BACK MY LEGIONS!" ... Awesome. It ended Roman dominion in Germania and pretty much Roman expansion in general. Germanicus was tasked with retrieving the standards years later and did so, because Germanicus was one of the baddest motherfuckers to ever Don the purple. You don’t get renamed Germanicus Gaius Julius Caesar for eating grapes and having orgies. Essentially, to answer your question - the Romans didn't have a problem fighting the Germans, they were actually quite successful, having administered victorious campaigns both before and after Varus... But Varus' complete and total defeat at Teutoburg was so haunting, the Romans wanted nothing to do with the place. So much so the 17th, 18th and 19th legions were never risen again, instead those numbers were left to rot in the mud of the Black Forest forever, as a reminder to Rome of its shame. I also think we see the Germanic tribes as implacable because culturally, the Romans chose to remember them that way - as seen in your Tacitus quote Edit: I shot a lot of this from the hip from my mobile- can tidy it up tomorrow/others can call me on my bs.

How did mammoth hunting cultures harvest the meat?

you should also try to ask this over at r/askanthropology but the current thinking is that the mammoth would be butchered where it fell. Bison (*Bison bison*), were much smaller and they tended to be butchered where they fell as well. There is a paper where they experimented by butchering a dead zoo elephant but I don't have my memory stick with me at the moment so I can't give you a reference, will try add it later

Do electrons really 'relolve' around the nucleus?

> If an electron exists as an electron cloud, how can it 'revolve' around the nucleus? You've just realized one of the gaping holes in the Bohr model. > Or do they not revolve at all? Not really. They just have certain probability distributions that describe where they're most likely to be. > If so, why do we say that they have some angular momentum? Because they have certain numbers that act like normal angular momentum mathematically.

How were hurricanes tracked in the 17th and 18th centuries?

hurricanes were not 'tracked' in the 17th and 18th centuries. There was little understanding of cyclonic storms and no means of instantaneous communications. A track could be made well after the fact, but that was not 'tracking' in the sense we use the word today.

The question that my professors/teachers have never been able to answer. What's the lowest temperature a flame can have.

You question is nearly impossible to answer because there really isn't a good formal definition of a flame or fire. It's more of an, "I know it when I see it" thing. There are plenty of chemical reactions that give off both heat and light that can occur at low temperatures. If you managed to get a photoluminescent molecule like luminol into the gas phase and catalyzed it's oxidative decomposition, it would make something that you would probably call a flame, but it wouldn't be hot at all.

what happens after you burst a blood vessel? does the vessel itself reform or do you have a gap there forever?

It's called a bruise. The blood leaks out under your skin and makes a spill. The body patches up the vessel, or seals it off if it's too damaged. Then it cleans up the mess, that's why the bruise turns colors as the crashed blood cells get cleaned up, like after a highway crash. Then you are fine. Other nearby vessels expand and/or new ones grow to ge4t the traffic flow back to normal.

Do any non-human animals "remember" things in a way like humans, or only through conditioning? Can an animal "remember" another animal that harmed it? Can an animal plot revenge?

Crows remember shit for years. [here](_URL_0_) Another example is a silverback that, through sign language, described his mother being killed by poachers. He was full grown. [here](_URL_1_) ...now if only my dachshund would remember us saving her when she was a pup next time she has the urge to leave us a "treat" on the floor...

How much radiation does a single banana give off? How many bananas would it take to kill someone and how long would that process take?

You basically couldn't kill someone by just piling bananas around them. The amount of radiation you need to get someone to kick the bucket is on the order of 2-5 Gy (joules per kg). Even using natural K metal (with a small % of K40), being surrounded by an infinite sphere wouldn't even come near a harmful dose. You'd need to separate out the K-40, then pile it around/in someone. I suspect you'd need on the order of a couple of Ci (1Ci = 3.7E10 Bq) to cause harm, which would require you refine ~10^6 - 10^7 kg of natural potassium. TL;DR: Ain't happening

how is youtube a sustainable business model? if view count remains constant but video storage costs continue to increase, wouldn't this lead to a permanent loss?

Storage costs are going down exponentially. Every year the cost of storing 1 GB of data is half what it was the previous year. YouTube loses money every time someone uploads a long video that nobody watches, but it doesn't matter because they make insanely high profits off of the top 1% of the most popular videos. As long as YouTube is a good place for popular videos, the business model is sustainable. If it turned into an unpopular site where people just uploaded their personal videos but nothing popular or viral ever went there, it'd lose money.

does *absolutely everyone* on the sidelines of an nfl game have a reason to be there?

No. Some people including some family members and celebrities are occasionally allowed on the sidelines. Most of the people there are necessary though.

facebook scams. what do the accomplish by getting you to share a post?

They are often designed to build up likes and followers then the owners of the page (usually located in a developing country not always though) will sell the page to scammers who can reach a giant audience (iPhone giveaways porn spam snake-oil weight loss solutions etc)

how do web browsers work?

When you request _URL_0_, the server sends back a bunch of textual data. Plain text is boring to look at, so a simple markup language was created named html. The browsers job is to parse through the html and display it nicely. Some browsers display things differently than others (that's why many people hate internet explorer). Requesting for a page can be very resource intensive on the browser (intensive in a very relative term). Most sites share similar layouts, so each request may be 95% of the same data (things like the header, footer). It doesn't make sense to request almost the same thing, so caching was invented. A browser stores commonly requested things locally on your computer. Caching improves the time for pages to load, since most of it is stored locally. Offline browsing uses the cache to save complete pages. If all the content is saved onto your computer, then you don't need a connection to view it. Thus, offline viewing. Offline viewing is only practical for pages which have content that never changes. If the page depends on any user submission, then obviously it won't work. A session is an exchange of information between the browser and the web application. They use 'cookies' to keep this information sorted. Cookies are nothing more than simple text files that your browser manages. Sessions and cookies are used alot in the internet, but for the average five year old, they keep you logged in for a specific time on a site. Cookies are the reason why you stay logged into Facebook on your computer. The cookie is stored only on your computer. As for security, browsers don't do much. They can recognise certificates a site must have in order to be 'secure' (Called an SSL certificate). They can also recognize an invalid one too. They aren't smart enough to do much else though, that is left up to the user. I hope this helps!

When the United States annexed the former territory of Mexico (California, Utah, Nevada, Arizona, New Mexico, Texas), why were the Spanish names of cities such as Los Angeles and San Francisco retained?

generally speaking, pre-existing towns or settlements weren't renamed, and san francisco is the exception. [according to the 1847 ordinance changing the name of the town,](_URL_0_) "yerba buena" was renamed "san francisco" to prevent confusion. [look, for instance, at this 1839 American map of the US and Mexico-- the settlement of yerba buena is mislabeled as "st. francisco,"](_URL_4_) but the other dots on the map of california generally correlate with their modern names. [see also this 1846 map,](_URL_1_) where most settlements (except for modern sacramento) have recognizable names-- and the settlement on san francisco bay is called "san francisco" by the cartographers rather than its proper name of "yerba buena." there was no wholesale renaming. don't forget that a sizeable number of mexicans living in california flipped over to the american government during the mexican war. i'll turn it over to a previous post i made, detailing the chaotic conditions in mexico that led to californios going over to the american side: [Copy-pasted from a previous reply](_URL_2_): > [in addition to the internal warfare over control over the government, major portions of the country tried to secede.](_URL_3_) while the republic of the rio grande and the republic of yucatan never really got off the ground, texas managed to successfully beat back the mexican army and gained its independence in 1836. > california was not excluded from this political turmoil, and several mexican governors ended up getting being violently removed-- california governors micheltorena, gutierrez and victoria were all deposed by violent revolt. mexico was doing so badly at the time that multiple former mexican governors of california actually were in favor of being annexed by foreign powers. the relative stability brought by the americans was welcomed by a significant portion of californio society, including mariano vallejo, the richest man in california. many of the rest, like former mexican governors andres pico and pio pico, ended up staying on after the switch to american control and remaining prominent citizens. (andres pico, for instance, was elected to the california legislature and served in the state militia after the americans took over.) given this chaos, and the defection of large numbers of the californio elite, it's not surprising that the names stayed in place. i have a handy table of the spanish, english, and modern names of the places marked, too, from north to south. Spanish name | English name (1846 map) | Modern city ---|---|---- Nueva Helvetia | New Helvetia | Overtaken by the adjacent City of Sacramento in the 1800s Yerba Buena | San Francisco | San Francisco Misión Santa Clara de Asís | Santa Clara | Santa Clara Pueblo San José de Guadalupe | San Jose | San Jose Monterey | Monterey | Monterey Misión San Miguel Arcángel | San Miguel | San Miguel Misión San Luis Obispo de Tolosa | San Luis Obispo | San Luis Obispo Misión La Purísima Concepción | La Purissima | Lompoc (named after the local ranch rather than the mission) Misión Santa Bárbara | Santa Barbara | Santa Barbara Misión San Buenaventura | San Buenaventura | Ventura (but the official name is still San Buenaventura) Misión San Fernando Rey de España | San Fernando | Mission Hills (neighborhood of Los Angeles); the City of San Fernando is less than a mile away Pueblo de Nuestra Señora la Reina de los Ángeles del Río de Porciúncula | Pueblo de los Angelos | Los Angeles Misión San Juan Capistrano | San Juan | San Juan Capistrano Misión San Luis Rey de Francia | San Luis | Oceanside (mission seized by the U.S. Army until 1865 and fell into disuse) Misión San Diego de Alcalá | San Diego | San Diego

Books on U.S.-Native American wars

I quite enjoyed: Jill Lepore, The Name of War: King Philip’s War and the Origins of American Identity (New York: Vintage Books, 1999). It covers one of the earlier conflicts to take place and explores some of the different perspectives and sources on the conflict.

municipal fiber internet. is it funded by the government or is funded by taxes? or do you just pay for it like you would for any other service (i.e. comcast, xfinity, etc...)? how does a town go about getting it (that is if they are in a state that doesn't ban it)?

As the name suggests Municipal Fiber Internet is provided by the municipality (local government). The organization and funding of this is up to the municipality as is the same for any municipal utility like water, sewage and roads. It is not uncommon for the local taxes to pay for some of it however most strive for the utility to become fully self funded. Quite often the municipality only offers financial security to the endevour which is enough to get loans that will be paid back by the subscribers over the lifetime of the infrastructure.

why do salt water and fresh water bodies stay seperate

Land for the most part. Lakes are fed by rainfall, and they occur most often in mountain valleys. Rain falls down the mountainsides making creeks and rivers that feed into the lake, and the water has no where else to go. When rivers feed into the ocean the fresh water mixes and eventually becomes salt water. This influx of fresh water is offset by evaporation, which becomes clouds, which rains to create the fresh water in the first place.

Im interested in theory of pre-historic advanced civilizations is there any reading material that you could recommend?

Hey there! You're right that it's not a commonly accepted theory, and for good reason. There's no evidence. Most arguments for it are based on "We don't know anything about this era.. So it could be?" This mentality hardly lends itself to any kind of scholarly research, which is based on making conclusions from observations. While I can recommend some good books in why the "lost ancient super-civ" trope is so prevalent in the West, or on what excavations reveal about the earth during the era of these hypothetical civs, if you would like, but I have never seen a book with anything resembling a scientific approach that takes ancient advanced civs seriously.

how powerful does a nuclear warhead have to be to destroy our planet?

Planets are pretty big thing and pretty hard to destroy. Even if you somehow managed to shatter a planet to pieces the pieces would just be drawn back to each other to reform a planet unless you pushed the pieces very, very hard away from each other. There is a theory that Earth was impacted by a very large and fast object very early in its development and that the impact was energetic enough to push out a massive amount of molten rock and debris that eventually formed our moon. That was literally an earth shattering kaboom and the planet still was only changed but not destroyed in the process. Wikipedia says that the largest nuclear explosion ever was when the Russian tested their Tsar bomb. It was theoretical a 100 megaton bomb but they tested it at 50 mt which works out to be about 2.1×10^17 J. Wikipedia also gives the energy released by the asteroid that killed all the dinosaurs (except birds) as 5×10^23 J. This means that impact was about 2 million times stronger than the strongest atomic bomb and while it certainly ruined the day for everyone a round at the time it didn't destroy the earth or kill all our ancestors (little furry things that they were). Wikipedia also gives a value for the gravitational binding energy of Earth (which I assume would be needed to overcome to blast the planet apart) as 2×10^32 J. This would be 10^15 (a quadrillion) times higher than the largest nuclear explosion ever. You can't really imagine a quadrillion times of anything with a human brain, but it is a lot. We can't scale up nuclear bombs that big. So the Earth is safe from being blown apart by man made nuclear explosion. That is good. As the above value for the dinosaur killing impact shows we are probably also safe from completely destroying our own ecosphere on top of the planet. It is much more fragile than the planet itself, but it has survived explosions a million times bigger than anything we ever made and came out fine eventually. So we won't kill the planet or life on earth. Humanity is even more fragile than life on earth. The giant impact above killed of all land species bigger than a medium sized dog. That sort of thing would have a good chance of killing of humanity. Even more fragile is human civilization. You don't need to kill of all humans with the explosion just make it big enough that the survivors will be bombed back into a stone age. That would be still too much for s ingle full yield tsar bomb, but the nuclear powers of the world have enough bombs to be able to confidently cause a collapse of human civilization, with a small but non-zero chance of total human extinction. The earth will be fine. We won't.

In the Americas, why are Spanish-speaking countries so small and numerous, but there are two enormous English-speaking countries?

After Simon Bolivar drove out the Spanish in South America, he was briefly president of much of Spanish-speaking South America. His vision was for it to be a united country. Other political factions felt differently. Further north, Mexico and Central America were briefly united after independence -- they were all administered as part of New Spain by the Spanish. Then, modern-day Central America was united as one country for a bit before breaking up into different countries like it is today. The reasons were different from place to place, but generally speaking, despite having the same language and some cultural similarities, there were too many different political factions, different local leaders who wanted power and not enough of a sense of national unity for these big federations to be workable in the long run.

why are eggs almost universally sold in packs of 12? what made farmers agree to sell this way?

TLDR; Convenience, 1 shilling = 12 pennies, 1 egg = 1 penny. No need to make change. Under a system that came to be known as English units, which was a combination of old Anglo-Saxon and Roman systems of measurement, eggs were sold by the dozen. It made sense to sell them that way because one egg could be sold for a penny or 12 for a shilling, which was equal to 12 pennies. That system held sway in the American colonies and persisted after the revolution, becoming part of the system known as U.S. customary units. Such units are used for consumer products and in industrial manufacturing. The British have moved on, adopting a wholly new system of weights and measurements in 1824. But they still mostly sell eggs by the dozen. Thus, in the United States, a vast majority of eggs are sold by the dozen, half-dozen and other multiples of 12. But in India and parts of Africa, it isn’t unusual to buy eggs by the piece, and in some countries they may be sold by 10s or 8s. 

What's the advantage of having a long lifespan?

Human bodies, especially our brains, take a very long time to develop. We "traded off" our speed of evolution in order to get a more complex body/mind. Part of the reason that huge plants/animals have the longest life spans is so that they don't need as fast of a metabolism to grow to full size. A 1000-kg animal with a 1-year life cycle would have to eat several tons of food in a few months to become an adult. However, a 1000-kg animal with a 50-year life cycle only needs to eat enough food to maintain its current weight, plus a little bit extra for growth.

Are animals aware of their own shadows and the shadows of other animals and objects?

I think the best comparison would be to a mirror. It answers the same basic question but is more explicit. Most animals cannot recognize themselves in a mirror although there are a few exceptions, mostly birds and primates. About half of all magpies, for example, are able to recognize themselves in the mirror. Interestingly enough, they also seem to know what they should look like and when something is different such as a yellow sticker placed on their feathers.

Other than living in a simulation, what other possible implications does this have?

He published an article about this in *Physics World*, 2010: [Symbols of Power: Adinkras and the Nature of Reality](_URL_0_)

What role did Persia and Persians play in Greek mythology?

There are no Greek Myths relating to the Persians or Persia directly.

Could someone explain the differences between and advantages/disadvantages of the different antiseptics? iodine vs alcohol vs peroxide, vs etc?

[Here](_URL_0_) is a well-cited review of several antiseptics, including the ones you mentioned :)

how does "lottery wheeling" work?

The only part of the Wikipedia article you need to pay attention to says that wheeling does not change the expectation value of the ticket. That means that the probability of paying more for the ticket than you win is still nearly 100% and the more you play, the more you are expected to lose.

How can I have 80 billion direct ancestors going back to just the 13th Century?

You were made by 2 people, who were made by 4 people, who were made by 8 people... etc. Not including siblings.

the difference between public and private sector labor unions

A public sector labor union is a union comprised of government workers. A private sector labor union is a union comprised of private employees. The biggest difference is that public sector labor unions largely negotiate with other government employees or politicians for their contracts. Private sector employees negotiate with the company's counsel. Private sector unions negotiate for a larger share of the profits they help create. Public sector unions negotiate for more tax funds. It is for this reason that even FDR (extremely liberal president) was highly against the idea of public sector unions.

given how hard it is to start and run a successful small business nowadays, how were so many immigrants able to come here with nothing, and and still start up businesses in the cities where they settled?

In the old days there were extremely few regulations, and they were not well enforced. If you wanted (for example) to buy some stuff and sell it retail from a wagon on the street, you could just start doing that.

How long did it take to create marble sculptures? Weeks, months, or years?

"Months to years, it depends". Many of the famous Renaissance sculptures took between one and three years. Almost three years for Michelangelo's David (september 13th 1501-early spring 1504), about two for Moses, and almost two for the Pietá (1498). Donatello spent more than two years on each of Zuccone, Saint George and Saint Mark, working with several assistants. Sources: _URL_0_ "Donatello: Sculptor" by John Wyndham Pope-Hennessy

why do doctors flick syringes before injecting someone? is this just a thing they do in tv shows?

They are checking for air bubbles. Injecting a air bubble into a blood vessel can easily kill a person.

the difference between single phase and three phase power

Both are forms of alternating current (AC) Alternating current cycles from +120V to -120V, 60 times per second (assuming you live somewhere that uses 120V 60 Hz for mains power) Single phase power means that all of the power in the wire alternates from +120V to -120V. Three phase power has three wires, all alternating from +120 to -120, all at the same frequency, but they are offset from each other. Basically, when Phase 1 is at its peak, Phase 2 is in the middle, and Phase 3 is at the bottom. So in 3 phase, there's virtually always a wire at 120V or very close to it. It delivers a steady stream of power, and that makes it much more useful for higher electrical loads.

can smelling something be unhealthy? like if there's a very bad smell, is there anything dangerous about the act of smelling it?

Yes. Stuff like paint- and glue fumes can be highly toxic. I don't think that "regular" bad smells like rotting fish or excrement are dangerous even in large quantities, but both foster a myriad of harmful microbes so the smell is evolution telling you to stay away.

My great uncle enrolled in the Charlemagne Waffen SS Division, is there online ressources I could check to find out what happened to him ?

Hi, hopefully someone can drop by to help with something more specific, but you might find these resources helpful : the sub has a wiki for finding military records [here](_URL_0_). You might also try x-posting to /r/genealogy for more tips.

I kept hearing about significant infantry combat doctrine changes during the first world war. What were the main changes among western military from 1914 to 1918?

There's a lot of talk on this and there's an idea here that many seem to struggle with greatly as it directly challenges this idea of "trench warfare" as a "thing". For each army it is different certainly so we'll speak for now only on the British and German side of things w.r.t. the Western Front. The French case is just a giant basket case of confusion but if you want to read on them in particular Robert Doughty's work *Pyrrhic Victory: French Strategy and Operations in the Great War* is **the** work on said matter. For the purposes of this post though I'll mainly be working off of Richard Holmes' *Tommy: The British Soldier on the Western Front*, Martin Middlebrook's *The Kaisers Battle*, and *Through German Eyes: The British & The Somme 1916* by Christopher Duffy. Holger Herwig's *The Marne: The Opening of World War I* is also a wonderful source on this matter. So let's run over this. The war can be broken, roughly, into four phases: * **Summer 1914 - Winter 1914: The War of Movement** The battles of this period would look distinctly Franco-Prussian War-esque in nature. In 1916 a Division General would have at his disposal 204 machine guns but in 1914 that number was 24 for 10,000 rifles. They were, in other words, very short on ordinance for the regular infantry and the doctrine reflected that of late 19th century warfare because of such. This would be dominated by what are so cleverly called skirmishing lines. Men would spread out with something of 3 meters on either side about 70 men long with the next row about 25 meters back. Further back, about 200-500 meters, the rest of the battalion would remain in column formation and send up "waves" to reinforce the skirmish line. The combat of this period would not heavily rely on grenades nor mortars or light machine guns; notably because both sides had a distinct lack of such. Fire and maneuver and general suppression based warfare were the name of the game. A very fluid form of fighting to say the least. * **Spring 1915 - Fall 1916: Stagnation** A big issue with a lot of amateur WWI historiography is that people try to find all these tactical level reasons for why trench warfare developed. As if both sides just happened upon machine guns and blundered into it. We must remember, first and foremost, that trench warfare was an operational and strategic *decision* by the upper commands of *both* sides; almost a mutual agreement of sorts as a pause in the fighting benefited both tremendously. They soon found, however, that that pause became increasingly more difficult to break. The Germans had the benefit of choosing the most defensible positions in France/Belgium and thus were very, very, very well defended and the longer things went the more fortified their positions got. Same for the Allies. This is where we go to infantry tactics. This is also when Kitcheners New Army and basically the B Team's of all armies started to swarm in; not the main force by any regards. These were, by and large, thoroughly untrained troops and non-battle hardened. Thus the skirmishing lines were tightened. It was perceived, and we can't divorce the infantry from the artillery here unfortunately, that the *artillery* did the fighting and the infantry *occupied already conquered land.* By and large though there was no general doctrine for the British in particular; the first Tactical Manual appeared in March 1917 which we will talk about later. By and large it was up to Divisional commanders or even Battalion commanders to decide, on their own whim, how to conduct battle. For instance at the Somme General Rawlinson highly recommended/commanded that the soldiers do not advance behind the artillery barrage and only go over after the barrage has ceased to occupy the trenches (he did not want friendly fire); most of those who fought in the battle disregarded this and did very 1917/1918 looking tactics. They would travel shortly behind the barrage and strike the enemy trenches right as the barrage passed over to shock the enemy. Throughout 1916 we see an absolutely enormous increase of reliance on the bomb, or the grenade in other words. How a general trench assault would look like would be men advancing on a position while rifleman suppress the enemy. The Lewis Gun, which would now accompany at least every Platoon, would also contribute to this but in a lesser relied upon degree. The barbed wire would be cut while bombadiers laid to waste the enemy trenches. Grenades were how battles were fought by the infantry first and foremost above all else. Flamethrowers would be used in large mass as well as trench clearers; basically once things got into the trench it became a shitshow of brass knuckles, knives, clubs, flamethrowers, pistols, so forth. But leading up to that point? Grenades. Lots and lots and lots of grenades. * **Spring 1917 - Spring 1918: Defense in Depth** Throughout 1916 both sides would begin experimenting with a more fluid style of fighting; for the Germans this would culminate in creating specific divisions for specifically highly trained, highly experienced soldiers to perform deep infiltration missions; Stormtrooper tactics. For the British this meant evenly applying it across the *entire* army as a doctrinal overhaul. Far less sexy but, in the long run, far more effective. As more Lewis Guns got into circulation the reliance upon them would increase significantly; eventually every Section (15 men) of every Platoon (60 men) of every Company (240 men) of every Battalion and every Division and so on would have a Lewis Gunner while every man was trained to use it. This document, which overhauled British doctrine and was their first tactical manual of the war, is called "The Normal Formation for the Attack" issued to the British General of Staff, February 1917. Some relevant bits: > *" . . .the frontage of an Infantry Battalion in the trench-to-trench attack may range from 200 yards against a highly organized position, to 600 yards or more against one less highly consolidated."* . . . > *". . .the rifle and bayonet and bomb [grenade], being the most effective offensive weapons, should be placed as far forward as possible, closely supported by the [rifle grenade](_URL_0_), which may be regarded as the "howitzer" of the platoon, and the Lewis Gun [portable machine gun], which is the weapon of opportunity.* > *Each platoon will, therefore, normally be disposed in two lines, bombers and riflemen in the front line, rifle grenadiers, and the Lewis Gun in the second line. These two lines will constitute one Wave . ."* . . . > *". . .[firstly] in the assault every man is a bayonet man, exceptiong No. 1 of the Lewis Gun, secondly, that every man in a bomber; and thirdly, that every man in rifle sections [14 privates + 1 lance-corporal] is also trained to be either a Lewis Gunner or a Rifler Grenadier, with a view to replacing casualties in men armed with those weapons."* . . . > *". . .extensions between men . . .should usually be from 4 to 5 yards. . .The distance between lines should be from 15 to 25 yards . . . between waves from 50 to 100 yards."* . . . > *"The assault may be carried out either by:* > *(i.) The leading wave going straight to the furthest objective, rear waves following it to the nearer objectives.* > *(ii.) The leading wave being directed to a near objective, rear waves passing through it to those further away, i.e. 'leap frog'."* In other words? Sounds *a lot* like 1914 styled warfare but with a lot more nice toys. Thin skirmishing lines spread out; machine gunners would support the advance while rifle greandiers and bombadiers suppressed the enemy. So how did the Germans respond? Well after the defeats at both the Somme and Verdun not only did they have significantly less manpower they also had a lot less leeway to risk on the front. In 1917 they would abandon what is called static defense for what is called defense in depth; in other words they would abandon the notion of not losing an inch of ground to purposefully allowing land to be taken for the purpose of launching local counterattacks. The front would not be so hotly contested. Rather than thick mazes of trenches they would be replaced by pillboxes and foxholes/crater holes (functionally the same) littering the battlefield. Sporadic machine gun nests and a highly functioning logistical component allowed 'outposts' to signal enemy advance, 'advanced lines' to hold off the enemy long enough for local reserves to run up to the 'main line of defense', a static defense, and the 'advanced lines' to resist the enemy. Let them take the land, barrage the land behind them to restrict reinforcement and/or retreat, counterattack locally. * **1918: Last Resort** The only real major doctrinal change that we would see in 1918, though it bears mentioning, is the German application of Stormtrooper tactics in the West. Basically it's the principal that if the weak positions are all taken by infiltrated, highly specialized forces then the strong positions are not so strong any longer but are isolated and weak. However the very strategic position Germany was in (and we can't divorce the tactical from the strategic here) did not allow them to advance as entire front as was preferred and what the British style of war was designed for. They were on their last leg; they had to penetrate *deep* and encircle the British and seize Paris. On top of all of that though they had no real support as they were deep infiltration units; so more often than not they were fighting without artillery support. On top of this all due to the rapid nature of their mission they *never actually hit those strong positions*; all they did was seize a bunch of strategically unimportant land.

Feyman diagrams and gauge bosons?

Yes, the axis represents time. Feynman diagrams are not a literal depiction of what’s happening, so the fact that the positron arrow looks like it’s pointing backward in time doesn’t mean that any particle is literally moving backward in time. The gluons are the gauge bosons of the strong force, and the photon is the gauge boson of the EM force. Beta decay is a weak process, so the virtual particle here is one of the weak bosons (W^(+/-) and Z).

Why is it that high current is dangerous but high voltage (to a certain limit) is not as dangerous?

We can be killed by 0.01A across the heart. An amp is quite a lot really. When you are electrocuted, what kills you is amperage across the heart. Enough amperage and it interferes with the heart's natural electrical signals, stopping it. Voltage and amperage are two different aspects of the same thing. Think of it in terms of water flow, where voltage is water pressure, and amperage is the actual amount of flowing water. A squirt gun may squirt water faster than a river can flow, but a river obviously has a lot more water overall. Voltage and Amperage have a linear relationship with Resistance. You feed something a certain number of amps, and the resistance will determine the voltage that makes it through. Feed it a certain number of volts and the resistance will determine the amount of amps that make it through. Resistance, in our water analogy is like the nozzle to a hose, where you can have a wide nozzle that gives out a lot of water slowly (low resistance = low voltage high amperage), or you can have a small nozzle that shoots a small amount of water out really quickly (high resistance = high voltage, low amperage) So anyway, if a shock travels through your heart, and the voltage is high enough to overcome the resistance, and the amperage across the heart is over 10mA, it can interrupt your heart's electrical signals, causing cardiac arrest. Sorry if I explained this like an ELI5, but if you want further reading try [here](_URL_0_) and [here](_URL_1_).

Why do we not perceive the expansion of the universe?

We're not growing larger. Space inside our bodies is expanding, yes, but our cells aren't "anchored" to this space. They're anchored to each other. If you spread your arms wide, your fingertips are continuously moving towards each other at the same rate that new space is appearing within you. Imagine this: Take two lego bricks, put them together and lay them on a rubber surface. Then stretch the surface. The lego bricks don't separate, because they're joined together tightly and the rubber surface isn't pulling on them enough to separate them. That is why you're not getting bigger, your journey to work isn't getting longer, and you don't have more stairs to climb every day: all those things are bound together like your lego bricks. But when you consider two galaxies that are far apart and not really bound together in any way, that is like two separate lego bricks on your rubber mat. The distance between these grows larger as you stretch the mat.

does a house ever finish settling?

Short answer: no Long answer: I believe it is never settled because it's the materials of the house expanding due to the heat of the day and then contracting when it's cooling down at night

Did the Spartans suffer from demographic decline because their women were less willing to have children?

The answer to your question is no, and the best way to describe the linked comment is "horribly wrong". Horrible because it blames Spartan women for a development that was wholly the result of laws and customs drawn up, enacted, and enforced by Spartan men. Women's subjection to these laws and customs meant that they were routinely made to suffer countless horrors and indignities, including the complete loss of their reproductive autonomy. Most of the TIL thread consists of poorly understood anecdotes and rampant nonsense, but this comment is particularly awful, so I'm glad you asked about it here. It is true that Classical Sparta went through a spectacular decline in citizen numbers. They started the period with about 8,000 adult male Spartiates and ended it with fewer than 1,000. But no scholar would blame this on the behaviour of women. They point to several other reasons, starting with the catastrophic earthquake of 465 BC which almost completely levelled the city. Success in war mostly kept combat losses low throughout the 5th century BC, but in the next century these really started stacking up, with hundreds of Spartiates lost in battles like Lechaion an Leuktra. But by far the most important reason was the property threshold for Spartan citizenship. In order to be a Spartiate, you had to pay your contribution to the common mess - a donation of wine and meat to share with your *syssitia* (tent group). If you could not afford to make this regular donation, you were stripped of your citizen rights. There is no evidence that it was possible to regain them once lost. In other words, the Spartan citizen body wasn't shrinking because Spartans were dying; it was shrinking because people were constantly being kicked out. There were many reasons why most Spartiates were getting poorer and falling below the property threshold while a small cadre started to hold all the land and wealth. The earthquake and subsequent helot revolt, the uneven distribution of spoils of war, and the extreme favouritism inherent in the Spartan social system all played their part. But the main factor seems to have been the Spartan practice of partible inheritance. Unlike other Greek states, the Spartans divided their inheritance equally among all children - including women, whose inheritance usually took the form of a large dowry in her own name. The result was that estates were constantly splintering, and many sons found themselves unable to afford the social status that their fathers had held. Meanwhile, since women were under no similar obligation to pay mess dues, their status was more secure. Moreover, unlike elsewhere in the Greek world, they were allowed to own land. The result was that the richest men, but also the richest women, were able to gobble up the patchwork remains of many fragmented estates as the majority of the citizen population fell into poverty. Aristotle gleefully blames the decline of Spartan power on women owning property, but this is just an outsider's misogynist prejudice; the situation was not in any way their fault. The fact that by the 330s BC about 40% of Spartan land was held by women is a *symptom* of the problem, not the problem itself. The Spartans, however, didn't respond to the situation by reforming their inheritance system or changing their property requirements, but by encouraging Spartiates to have more children. At some point in the 4th century BC, it became punishable for a man to be unmarried; there were sanctions against childless marriages; having children was framed as a moral obligation to the state. It became permissible (or even mandatory; our sources don't agree) for old men married to young wives to select a favourite from among the younger Spartiates to father children on their behalf. It also became permissible (or mandatory) for men who didn't get along with their wives to ask other Spartiates if they could impregnate *their* wives instead. This is where we see why the linked post is so profoundly wrong. A Spartan woman may have had a relative degree of autonomy in matters of property ownership and management, but she lived in an extremely patriarchal society, and men wrote the laws that shaped her life. In her late teens, she was made to marry a suitable Spartiate, who would be at least a decade older than her (and possibly much more). If her husband was too old or too disinterested in getting her pregnant, she was at the mercy of his choice of who might do so for him. If her husband was happy for an interested third party to try to get her pregnant, she had no choice but to accept it. Indeed, if her husband decided that *he* had provided the state with enough children already, he could decide to lease her remaining fertility to another Spartiate, and there was nothing she could do to protest it. In other words, it's not just that Spartan women didn't have the freedom to decide whether or not to bear children; it's that the laws introduced in response to shrinking citizen numbers *deliberately took away what little reproductive autonomy they had* in order to fix the problem. The Spartan marriage ritual itself was focused entirely on producing children, and took a form that can only be described as traumatic: the bride was made to lay down in the dark, head shaved, alone, waiting for the groom to appear at a time of his choosing to tear off her clothes and drag her to bed. This would continue nightly until the bride was pregnant. The girl herself - aged perhaps 18 or 20 - was expected to play along with enthusiasm. The final outrage of the linked post is the suggestion that wives would be rewarded if they gave birth to 3 sons. What Aristotle actually says is that when this happened, *the husband* would be rewarded with exemption from military service. If he produced a fourth son, he would be exempted from taxes as well. His wife never got anything. Indeed, as I've just described, she might be introduced to some stranger favoured by her husband who might want to get 3 sons of his own out of her womb. In other words, women were not the cause of Sparta's declining number of citizens, but they were very explicitly the victim of Spartan measures to turn the tide. Blaming the demographic decline on the women reinforces a particularly heinous strand of socio-political thought, started by Aristotle, which suggests that giving women any rights or freedoms at all will lead to the inevitable collapse of society. It suggests that the way to "fix" the Spartan situation would have been to take away the limited, precious rights that women had in that society, as if they weren't already subject to the horrific exploitation of their bodies and lives for the purpose of birthing more Spartiates. A Spartan woman's only hope to gain control of her own reproductive system was for her husband to die, so she could live as a widow on her own estate. Until that happened, she was at the mercy of her husband and the cruel laws of Spartan society, which treated citizen women as little more than incubators for the children of citizen men. & nbsp; For a quick overview of the relevant evidence, I used A.G. Scott, 'Plural marriage and the Spartan state', *Historia* 60.4 (2011), 413-424, and M.G.L Cooley's sourcebook *Sparta* (2017).

in the shell sort algorithm, why are the numbers 1,4,10,23,57,132,301,701,1750 used? they seem to be ambiguous and are really confusing me...

Shell sort partitions the data. The exact partition is not that important, but the properties of the partition (i.e. "gap sequence") do affect the runtime. "Gonnet and Baeza-Yates observed that Shellsort makes the fewest comparisons on average when the ratios of successive gaps are roughly equal to 2.2." You need to have some numbers to do the partition, so those numbers are one set that is known to work well, but you can change them and it will still work. _URL_0_

Why are British colonies in the Caribbean so homophobic?

I feel this is a loaded question as Montserrat, the Cayman Islands, the British Virgin Islands and the Turks and Caicos Islands all consider homosexual activity perfectly legal. So perhaps the question should more focus on why Jamaica itself is so homophobic as being a British Colony past or present seems to not be a variable in the conversation. From what I can briefly turn up, it seems the compounded problem of poverty, lack of education, disease (HIV) and masculinity issues all tied in with religion.

Why is angular momentum one-sided even if a spinning object is symmetrical?

It is convention only, to allow scientists to talk to each other without having to describe which coordinate system they are using every time. Let me explain. The direction of the angular momentum of an object doesn't mean anything by itself. What matters is that when object A with angular momentum interacts with object B with angular momentum, that the angular momentum is conserved. Then, you can know how the objects will be acting afterwards. The reason we use these conventions, is that you don't always want to start back at the very beginning. Say you know how a certain experiment will end up, and then you want to move on. You can start with "this experiment will lead to an angular momentum in the +z direction" and move on, without having to describe what that means. If instead we used a left hand rule, but used it consistently throughout all calculations, everything would work out just the same.

How formative was Tolkien to the genre of high fantasy?

Tolkien is unquestionably the most influential figure in high fantasy, and I think it is not unreasonable to say that he and C.S. Lewis were the originators of the subgenre. The Chronicles of Narnia and The Lord of the Rings were both published during the mid-1950s. Earlier in their respective literary careers, Hobbit was published in 1937 and Perelandra in 1938, the former was not yet the fully-developed high fantasy of Lord of the Rings and the latter would be better described as science fiction. Tolkien and Lewis were good friends, of course, and often discussed their writings with each other. The roots of Tolkien's works lie primarily in medieval writings, especially Anglo-Saxon poetry and Norse epics like Beowulf and the [Volsung Saga](_URL_5_). Influences from farther afield, including the Finnish national epic the [*Kalevala*](_URL_9_), show up from time to time in his writings as well. Tolkien was, of course, a professor of Anglo-Saxon (and later of English language & literature) at Oxford, and was interested in poetry and languages since at least his late teenage years. In addition to being one of the all-time best selling authors in human history, he was an accomplished linguist, literary critic, and translator. The Book of Jonah in the Jerusalem Bible was translated by Tolkien, he made a complete translation of Beowulf as well as a highly influential lecture on it entitled [*Beowulf: The Monsters and the Critics*](_URL_0_), he did etymologies of Germanic W words for the Oxford English Dictionary, he wrote a vocabulary of Middle English, and he published translations of three Middle English poems: [*Sir Gawain and the Green Knight*](_URL_6_), [*Pearl*](_URL_11_), and [*Sir Orfeo*](_URL_1_). One particularly interesting aspect of Tolkien's writings, from a meta-literary perspective is that they are framed as a collection of writings which he discovered and translated from Elvish (Silmarillion and related works) and the Common Tongue of Middle Earth (the Red Book of Westmarch, written by Bilbo and Frodo-- the former of whom translated some Elvish source material for use in the book). Truly an irrepressible enthusiasm for philology. Also, if you read Lord of the Rings out loud to yourself, you will find many examples where Tolkien wrote sentences that pretty much could have been lines of [alliterative verse](_URL_2_), the style of Old and Middle English that many poems were written in, including Sir Gawain & the Green Knight, Pearl, and Sir Orfeo. Tolkien believed the world suffered from disenchantment: that along with the modernization of the Industrial and Victorian eras had come a reduced sense of wonder at the world, and a diminished willingness to believe in the fantastic and the terrible. In his essay, [*On Fairy-Stories*](_URL_3_) (seriously, read it, it's great), he explained his views on faery-stories and the importance of fantasy and mythology. He felt that they had been tamed, that the connotation of "fairy" (he often used the spelling "Faery" or "Faerie"--the spelling was important to him, as a discriminating philologist) had become domesticated and defanged, something you would meet in your garden rather than a dark forest, something adorable rather than something which should make you tremble. He felt that such stories described the world on a spiritual plane in a way that mundane stories about the real world could not. While at secondary school in the early 1910s, Tolkien and his three closest friends (Rob Gilson, G.B. Smith, and Christopher Wiseman) formed a private club they called the Tea Club and Barrovian Society, or TCBS for short. They talked about many things, including philology and poetry, which they also wrote and read for each other. After graduating from the boarding school, they remained in contact and visited each other. All of them considered the TCBS to be the center of their intellectual lives. It was during this period and his subsequent university education at Oxford that the seeds of his world began to grow. In 1914, he wrote a poem called *The Voyage of Eärendel the Evening Star* (published in the Book of Lost Tales 2), which later evolved into the culminating episode of the *Quenta Silmarillion*. It was based on a line of Anglo-Saxon poetry by [Cynewulf](_URL_7_). Tolkien later wrote that the name Earendil struck him as one that he could write stories about. His influence on fantasy is profound-- anything which has Orcs in it owes him for that invention, and anything with Elves or Dwarves (although both spellings exist prior to Tolkien, he is largely responsible for the thorough dominance of Dwarves and Dwarven rather than dwarfs and dwarfish) very probably owes him as well, since neither of those mythical beings had yet taken the well-defined shape that is present in Tolkien. Elves and Dwarves were ideas present in Norse/Germanic mythology, but their physical descriptions were generally quite vague or indeterminate, and "elfs" in particular could denote a wide variety of concepts of mythological beings, from frolicsome gnomes (which one can see in The Hobbit as well as some of Tolkien's earlier writing) to wicked spirits which are responsible for causing illnesses (a view represented in late medieval Britain). To [Snorri Sturluson](_URL_10_), the medieval Icelandic writer, dwarfs were dark-elves and light elves were what we might think of. In many cases both dwarfs and elves were thought of as simply beings which populated the unknown world on the periphery of human realms, hiding in mountain caves or deep forests, sometimes practically as animistic spirits, and rarely as the magnificent, ancient civilizations that Tolkien envisioned. Any time you see a representation of invariably bearded dwarves (which, let's be honest, is any time you see dwarves), you're seeing Tolkien's influence. Elves being the noble, cultured, ancient elder race is also attributable to Tolkien-- even in situations like the game Dragon Age, which another poster mentioned, where elves are a marginalized, formerly enslaved people, they were once much more powerful than humans. That game tries to buck a lot of standard high fantasy tropes (drawing on G.R.R. Martin's work in part), but the key point is that it still existed within a context where it doesn't even make sense to the player to use the word "elves" if they're not going to be a noble ancient race. Authors like Rothfuss and Martin have specifically said that they're trying to write something in high fantasy that *isn't* a rehash of Tolkien. I'm deeply sorry for the 20-year-rule violations, but the magnitude of Tolkien's influence is shown by the fact that until the last 20 years or so there were not many fantasy authors making a serious effort to do something wholly apart from Tolkien. Robert Jordan's Wheel of Time series had the first installment published in 1990 and was still clearly laden with Tolkien. After graduating from Oxford in 1915, Tolkien proposed to Edith Mary Bratt, married her in early 1916, and in the summer of 1916 shipped off to serve as a signals officer in the Great War that was then raging on the mainland-- a parting which caused both of them great distress, but it was just not very socially acceptable for a young, able-bodied man to refuse to serve in the war. He wrote the poem *Kortirion Among the Trees* while in a training camp in Britain in 1915-- Kortirion would later become the Elvish city on the isle of Tirion lying off the coast of Valinor. Besides disease and hostile shells, one of the chief dangers of the trenches was boredom. Tolkien's imagination had all the time it desired, and though it was nearly impossible to do any serious writing in the trenches, Tolkien nonetheless jotted down many an idea, which he would often expand upon during his time back from the trenches. "You might scribble something on the back of an envelope and shove it in your back pocket, but that's all. You couldn't write.. you'd be crouching down among flies and filth." It was during this period that he first began to dream up the two languages that would become the Elvish languages [Quenya](_URL_4_) (which he worked on first) and [Sindarin](_URL_8_) (which came later, in 1917, as a derivative of Quenya). Earlier in his life he had played with inventing languages, but never so thoroughly (nor with such a grasp of linguistic change) as during the period immediately after WWI. His history of Arda (the world which includes Middle-Earth) began in part as an explanation of the historical migrations of the Elves that led to the linguistic relationship between Quenya and Sindarin. The other three members of the TCBS were aleady serving in WWI by the time Tolkien joined, and they stayed in correspondence with each other regularly, writing poetry to fill their time. Rob Gilson died in the first days of the Somme offensive, which weighed heavily on the surviving three. Also at the Somme, Tolkien witnessed the advent of the tank, which made a great impression upon him, serving as inspiration for the description of Balrogs and dragons overrunning the walls of the Elvish city of Gondolin. He began writing *The Fall of Gondolin*, the first prose story about Middle-Earth in 1917 on the back of some military sheet music. The poems he had written prior to that point tended to become incorporated into the legendarium later on, but did not begin as poems about this other world. (continued in next comment)

why does scanning take so long if photocopying or taking a photo of something is so quick?

Because you have a cheap scanner. Cheap scanners are slow. Expensive high end scanners are very fast.

why do heroin users have to switch veins? what does the heroin do to “kill” the vein?

It's not the heroin. It's poking the same spot with a needle over and over again without giving it enough time to heal. It can get more complicated where if you *do* give it time to heal after you've abused it too much it will develop scar tissue which makes it harder to inject there.

how are things n% water?

Heat it until the water evaporates, check its mass before and after and calculate the percentage

Why do shadows "kiss"?

This is because the sun is an "extended" light source, as opposed to a point light source. Because of this, there is an area called the [penumbra](_URL_1_), where the shadowing object creates a partial shadow. When two penumbras meet, it makes the "kissing" darker shadow. See also [Shadow Blister Effect](_URL_0_)

how usa is one of top polluters in most sources but is consistently ranked relatively favorably (in the middle) for how polluted it is?

A lot of it is just how big the US is and how much the population and industrial centers are spread out. If I have a country that is 100 square miles and pollutes x amount, and a country that is 1000 square miles and pollutes 5x amount, the second country pollutes 5 times as much as the first country but said pollution is spread out over 10 times the area, so would likely be only half as polluted. Oversimplified but still pretty accurate. The USA is the third largest country by area behind Russia and Canada and ahead of china.

the waco siege.

a ups driver was delivering packages to the compound and one broke open showing weapons, inert grenades and black powder. UPS reported this to the sheriff who contacted the ATF. This info along with reports of automatic fire from the compound led to sucspision that the Brach Davidians were illegally modifying weapons to be fully automatic. The ATF got a search warrant and prepared a raid. The Davidians knew the raid was coming. During the raid shots were fired but it is still debated who shot first. During the ensuing firefight, 4 ATF agents were killed 16 wounded and 5 Davidians killed, but the compound was not successfully breached which led to the siege and the FBI taking over. Eventually the FBI tried to gas them out using tear gas, during this fire broke out in the compound which spread rapidly. 76 Davidians were killed in the fire and 9 escaped

Napoleonic Era and Uniforms (Nit-Picky Questions)

So, there's a million questions. It would be beneficial if you reworded your question for a single question and ask a few over a few days.

what is the evolutionary benefit to a species, such as the praying mantis, to have the female kill the male after copulation?

By eating the male, the female gains a lot of nutrients, which will enable her to have healthier and stronger offspring. In this way, there is a higher chance that the genes of both the male and the female are carried on.

if someone is on death row and has a medical issue causing them the die sooner than their execution date, why would they be given medical help?

Up until the moment the executioner turns the key, the state must provide care for their convicted felons. The logic behind this is that up until that last moment, the execution is not 100% certain. There are years of appeals, and the governor might still pardon the convicted at the last moment. Also, allowing someone to die from a disease without treatment can be considered as cruel and unusual punishment.

it's common knowledge that exercising regularly and pushing yourself is good for your health and heart, but how does that logic work that the harder you work your heart, the healthier it becomes, instead of wearing it out?

The human body is a fascinating thing. It has been developed to be able to adapt to different lifestyles. When working out, you are essentially telling your body that for your lifestyle, you require stronger muscles. The body has learned to oblige to this, thus makes muscles stronger by adding more protein to the muscle cells (contrary to popular belief, the muscles do not gain more cells, the cells get more muscle protein, and become bigger in the process). If strong muscles are no longer needed for your lifestyle, the body will adapt to that as well, making you lose muscle.

How much variety is there between single celled organisms? Would two of my red blood cells be completely identical down to the smallest measure?

Two different questions really. Red blood cells aren't organisms. 1) Vast. 2) Potentially, but unlikely

Sickle Cell Anemia and UVR / Melanin Evolution Correlation?

It is because the sickle cell hemoglobin gene when it is heterozygous (meaning only one copy of one of your chromosomes and the other chromosome has a normal hemoglobin) protects against malaria. Since malaria is much more prevalent in tropical locations and so is darker skin, the sickle cell trait is selected for by evolution. In colder climates, where the population tends to have lighter skin and malaria is absent or very rare, there is no selective pressure to have the sickle cell trait and hence the disease is very uncommon.

why is it that when my battery dies on my iphone it takes 10 minutes to turn back on while connected to a charger?

Apple makes sure that the phone is charged to a minimum % (3%-5%?) before it turns on, to make sure it doesn't die again when you unplug it.

What is happening during the onset, peak and duration of a local anesthetic?

Local anesthetics, like lidocaine, work by stabilizing the membrane of cells. What this means is that they reversibly decrease the rate of depolarization and repolarization of excitable membranes. One such type of membrane is the cell membrane of pain-sensing neurons. By blocking the ability of the nerve membrane to depolarize, the local anesthetic blocks the ability of the nerve to send a signal to the brain, thereby eliminating the sensation of pain while the anesthetic effects are active. They do this mainly by inhibiting sodium influx into the cells by blocking sodium-specific voltage-gated channels. To really understand this, you'll have to review how nerves actually transmit signals. Then you'll be able to see how blocking a part of that cascade we can stop the signal transmission. Hope this helps, feel free to message me if you have further questions.

why does ukip have so many meps as opposed to other government positions?

UKIP supporters really, really, *really* hate the EU. Most everyone else just doesn't care about MEPs. So UKIP voters are more energized in European elections than the general public.

- why is, what seems like rape so prevalent in the animal kingdom?

Because most animals don't have morals. Humanity has gotten to a point of intelligence and society that we don't need to allow ourselves to just procreate willy-nilly. Cats, dogs, and other animals rape as part of procreation because they don't have the morals, the intelligence, the sense of caring for others, that says "maybe they don't want sex".

why don't vending machines keep their change topped up from the money people put in?

Filtering a coin box and setting it up so that it can provide change is possible, but requires a more expensive model of vending machine. Most vendors are willing to pay for a cheaper model because guess what, people are still going to use it.

What did ancient teenagers do for fun?

You mean a 'really' ancient civilisation such as the Greeks or the Egyptians, or will a more recent example do? Roman teenagers from the 17th/18th/early-19th centuries grew up in the street and the society they lived in was rife with violence. Every *rione* (ward) of the city usually had a long-standing rivalry with another, and these neighbourhoods' identities were very strong; for example, the people from Trastevere despised Monti, the *monticiani* hated Trastevere with a passion, everbody hated the Ghetto and so on. Thus many teenagers and their friends often formed what we'd call neighbourhood gangs, but - and this is an important point - there was no extorsion or racketeering going on: these hot-headed youths spent their days fighting the other youngsters from different neighbourhoods. These 'battles' often took place in the Roman Forum and were known as *battaglie a rocci* - stone fights, whose ammuniton was provided by the nearby ruins. Knife, sword (more precisely the *saracca*, a type of sabre) and even slingshot duels were also extremely common among young people, to the point that hospitals regularly received people with related wounds... especially during or after the Carnevale, as recalled by father Bresciani in his *Edmondo, o dei costumi del popolo romano*; an astounding number of youngsters died because of such forms of 'entertainment'. Hostarias, or pubs, were the quintessential meeting place for your average Roman and were also the kind of place in which brawls were much too common; these youngsters, but also their older counterparts, lived a honour-based lifestyle in which even the minor offences had to be 'settled' - you're looking at someone the wrong way? Snickering at that guy a table over? Then you're looking for *rogna*, or trouble. As mentioned earlier, Jews were also made the object of such 'innocuous' pastimes... when outside the Ghetto, they had to wear a yellow ribbon on their hats and were easily recognisable: many a youngster took one of them during the Carnevale and [made him/her roll down the Capitoline Hill inside a barrel](_URL_0_). Other forms of 'entertainment' during such a festivity was the *corsa dei barberi*, during which wild horses were made to run through the via del Corso and contestants had to stop them with their bare hands. Perhaps unsurprisignly, too many young people died this way. Card and dice games were *extremely* popular, and more often than not source of disputes... many of which ended up badly for the losing party. Favourite games were the *morra*, *faraone*, and the like but itinerant puppet theatres, the most famous of which belonged to the vitriolic Ghetanaccio, were popular as well; these often narrated the histories of fol poems such as the Meo Patacca. Finally, attending public execution (which were particulary cruel back then) was a popular pastime for both young and old people; *mazzolature* - during which the prisoner's head was smashed on a stone pedestal with the help of a hammer - quarterings and decapitations were also an occasion for social gathering exactly the same way a market or the hostaria were.

why do egg-whites foam when we whisk them and do not when there is just a very tiny amount of egg yolk in it?

The foam form the whites is formed by proteins from the protein-rich egg-white. The yolk contains fats that destroy the protein foam (also called an emulsion). You can try this by mixing in a tiny amount of cooking oil into the egg-whites: it will have the same lack-of-foam effect as a tiny amount of yolk.

how do we not run out of telephone numbers?

How did you get that figure? Did you do 10 factorial or something? Isn't it as simple as 10^10? Edit: you did do 10!, that's for a combination of things that exclude what's already been used and can't be used again. So a line of x amount of people has x! Combinations, you can use it that way because there can't be 2 tims, but phone numbers can have 2 7s

What memorials/monuments, if any, has the USA donated to other countries that is not about the US in anyway.

I think that the Marshall Plan was a pretty swell thing for the U.S. to do. It's not a commemorative statue, but you could probably find a list of many public projects that were completed as a result of the money. Almost all of the money was given in the form of grants and European countries, to my knowledge, were only asked to pay for the administrative costs of the program. We spent $13 billion on Europe, which was about 5 percent of our 1948 GDP. That's a *lot* of money in grants. Edit: Just for further comparison, in 2012, the equivalent project would cost around $754 billion, as a percent of GDP.

What exactly was the Battle of Actium?

Not to discourage any further answers but while you wait you'll probably enjoy these older posts: [What was Mark Antony's intention when he gave Rome's lands to Egypt in 34BC? And why did it take Rome two years to start a war against him?](_URL_6_) [What were some of the rumors about Cleopatra during the civil war between Octavian and Mark Anthony?](_URL_3_) [What positive things did Cleopatra do in her reign?](_URL_4_) [Did Augustus order the death of Caesarion or wanted to bring him first to the triumph like he pretended with Cleopatra, Caesarion's mother?](_URL_2_) [What happened to the Ptolemaic Egyptian bureaucracy after the Romans took over?](_URL_1_) [Were the trappings of the office of pharoah maintained in any way in Roman Egypt?](_URL_5_) [What was the religion of Egypt like after Cleopatra and before Christianity?](_URL_0_) By /u/cleopatra_philopater

seeing as video/picture quality is constantly increasing (1080p, 4k etc..), is there a limit to the quality that the human eye can notice a difference?

Theres alot of conversation about this actually... You really need to focus on DPI, since 1080p is very different on a 20" tv vs an 80". But then it matters how far away it is, and how good your vision is... Some would say we already eclipsed that limit with 1080p tvs at normal viewing distances. Yet... its trivial for a person to identify a 4k vs 1080p tv. Could they be seeing other advantages? better color? better source content? or is it something more than just how many rods and cones we have in our eyeball?

how do studios get to film in places as dense as new york without interrupting business and traffic, while also not being interrupted during filming?

I've got 10+ years working in the industry, my father was a camera operator and my grandfather was a Director/Producer of stage, TV and Film. The studio, via the production coordinator/manager, makes an agreement with the city, and they provide Police assistance to close down the area the crew wants to film in. Sometimes they simply use squad cars to block off the area, other times they use small, lightweight barriers, it depends a bit on how large and busy an area they need to close off. The city gets a huge fee to cover their costs (and a little extra) and businesses in the closed area are given a compensation for lost income. The city usually has stipulations on timing, and they generally try to avoid letting crews use any tremendously busy areas during normal business hours, especially in places like Times Square and the corner of Hollywood and Highland, which are huge thoroughfares for traffic and also cater to huge numbers of tourists who will be blocked from spending their money while filming is ongoing. However, this isn't a non-negotiable policy, if there's enough money on the table and the blockage will only be for a few hours, it can happen. Because of the cost and logistics, they usually try to expedite the process and be in and out as quickly as possible. It's also worth noting that soundstages and backlots around the world have a nice collection of extremely convincing recreations of certain areas, so there are many cases where they simply use a 2nd unit crew to get exterior footage of the actual area, and then film the rest of the scene on a lot or in a stage. Also, green screens - see the Times Square footage in the 2nd Spiderman, per another user's response.

why do large amounts of flammable material in a small space explode (ex: gasoline can) when ignited instead of just lighting on fire and burning like wood

Burning causes things to expand, heat up and release gases. if its in an enclosed space such as a pipe, grenade casing, gas can, etc... then the pressure from these reactions builds up causing the big bada boom.