query
stringlengths
20
300
positive
sequencelengths
1
1
negative
sequencelengths
1
1
What type of musical instruments would have been popular in the Caliphate of Cordoba circa ~1000AD?
[ "Going by the Great Book of Music of [Al-Farabi](_URL_0_) there would have been oud, psalteries ( somewhat like the present qanun), harps, drums, racks of bells, flutes- and singing, of course. The oud would make a great impression on Europeans, who would adopt it and call it the lute. Guitar is actually an anti-lute. The Spanish noted the Arab/Persian origins of the lute, and being intolerant of Islamic things created a guitar-waisted instrument with a similar tuning, which they called a vihuela. That later became the guitar." ]
[ "The only example I can think of is Saddam Hussein's son used one in Iraq. Uday Hussein kept an iron maiden in his torture chamber. _URL_0_" ]
Why is space black instead of white?
[ "[This paradox](_URL_0_) is actually pretty historically significant. The important thing you're forgetting is that the universe is not infinitely old and light is not infinitely fast, and so there are only a finite number of stars visible to us. Even though the stars are very large, the distances to them are larger, so that only a very tiny fraction of the sky would actually end at a star in terms of line-of-sight." ]
[ "When we look at something a million light years of distance away, we are seeing it as it was about a million years in the past. (It's not *exactly* a million because the universe has been expanding during the time the light has been travelling). So, using redshift to measure distance, we can figure out how far radiation has travelled, and how far in the past we're looking. So with sufficiently powerful telescopes, you can look back almost as far as you want. The \"almost\" is the trick though - we can't actually see the inflationary period because the universe was still so dense that it was opaque. What we can see is the \"cosmic microwave background\", which is the light from the \"last scattering surface\" - the light from when the universe became transparent." ]
How do joints/cigarettes stay lit?
[ "Air comes in when you take a hit, feeding the fire and thus making it \"larger\". If you light a cig or joint and dont puff on it, it will eventually go out" ]
[ "This is a more scientific answer than it sounds: it's all in your head. Try having a friend hold a pen there randomly half of the time. You guess when it's there, the more you guess the closer to chance you should get." ]
What is the purpose of fainting? What are the benefits of this mechanism? In extreme situations (e.g. being under attack) humans and animals sometimes faint but I see this as counterproductive and it would probability be better to become more alert in these situations, right?
[ "Our brains need a *lot* of blood to stay alive. Normally, our bodies work just fine pumping blood against gravity and up to our noggins, but sometimes things go wrong. If for any reason there's a drop in blood pressure or heart rate or reduced level of oxygen to your brain, your brain is going to make you faint. Why? Because it will make you horizontal very quickly, and that will help restore blood flow to your brain since your body is no longer working against gravity. So fainting (technically called syncope) is about preserving bloodflow to the brain, which will prevent brain damage. Preserving your brain is the paramount consideration. If your brain thinks it's not getting enough oxygen, it doesn't care about anything else in that moment. Anything that causes a sudden drop in blood pressure, or heart rate, or blood oxygenation can trigger fainting. Some of these things are physical, and some are psychological." ]
[ "Cats and dogs have been selectively bred to be good companions. Most animals find being petted extremely stressful and many would lash out if you tried. But those are poor traits for pets so we try to breed them out. There's an old Russian experiment with a fox farm that demonstrates this very nicely. At the farm they bred foxes in two separate carefully selected breeding pools. In one group they only bred foxes that showed aggression towards humans, in the other group they selected on very meek foxes. Eventually they had one group of foxes that was practically lunging at their cage to get out and attack humans while the other group of foxes acted like affectionate puppies. Exact same thing with dogs and cats. We bred out the behavior we didn't like. They enjoy human interaction because we selected for specifically those traits." ]
Is this recent heat wave a result of global warming, or is there another reason it's so hot right now?
[ "It's impossible [as I understand] to attribute any single climate event or short trend to global climate change - Only long term trends can be attributed to it." ]
[ "In cookery we have dry heat and wet heat. Wet heat is boiling and stewing - effectctively cooking by immersing in warm liquid. Dry heat is grilling or deep frying. Deep frying counts as dry heat since once the skin crisps, further oil does not penetrate it. Microwaves heat the water molecules in the food, and cook by boiling, which is a wet heat. Thus, the chips and pizza becomes soggy as if boiled or steamed - they should be cooked with dry heat. Edit: Or if they do not become soggy, they are heated without becoming crisped, which dry heat would do. Microwaving bacon is similar to frying, because of the oil content and thin-ness of the slices - but you need to lift the bacon off the ground (put chopsticks under it, or something) to prevent it becoming soggy." ]
Why do rubs from someone else feel so much better than rubbing yourself the same way?
[ "The same reason tickles feel entirely different. Your brain already knows exactly how you're going to touch yourself. Where when another person does it\\- it's a surprise sensation." ]
[ "Each instance of an object is unique, and reviewed by a human before being delivered. When you order something handmade, you know a person who is skilled in their craft spent a lot of time creating and determining that the product was suitable for sale. Manufactured products aren't all individually checked before shipping, only maybe 1% are. These products that are cheaper to make often have errors or corners cut on things like material as well to lower the price as much as possible. When you're already paying extra to have something made manually, there's little reason to make it with cheap material rather than good material." ]
If a storm is fed by sea water, how does the resulting rainfall come down as fresh water? What happens to the salt?
[ "The sun heats the water. Water vaporizes into the air. The salt doesn’t vaporize but stays in the sea. The water damp forms clouds and from the cloud it rains down again." ]
[ "Ever had a furry rug? If you rub it a bit, you'll be able to zap someone. Lightning is something similar. Clouds are like a big fluffy rugs that are constantly rubbing against other fluffy rugs. When enough charge is accumulated, they zap the Earth. ---- In a bit more detail: when you get enough power, you can zap through anything and create size of a spark you wish. To make that kind of power, you need to have difference between positively charged particles (ones that had electrons snatched from them) and negatively charged particles (those with too many electrons). Water and ice particles in clouds are constantly bumping into each other. These collisions tend to steal electrons from ice and give them to water. Because ice is less dense, it tends to stay higher in a cloud. Now we have a cloud with a lot positively charged ice particles on the top and a lot negatively charged particles at the bottom. These changes tend to accumulate to the point where discharge is inevitable." ]
How did American Political Language essentially become reversed in many cases
[ "The whole Red=Conservative/Blue=Liberal dynamic in the States is rather fascinating too. As noted, the U.S. TV networks began using varied color schemes in election maps back in the '70's. But it wasn't until the 2000 election (Gore/Bush) that they really took hold. The reason being NBC political reporter Tim Russert. According to [The Washington Post](_URL_1_), Russert appeared on NBC's The Today Show about a week before the election to go over the projections for the race. Just happened to be on that day there was a color-coded map that was Red=Republican, Blue=Democrat. Russert asked how George W. Bush would \"get those remaining 61 electoral 'red states', if you will?\" The election would turn out to be highly contested, eventually requiring a Supreme Court decision (Bush V. Gore). The case dragged on for months and the terms \"Red State\" and \"Blue State\" caught hold in the media, and later for the American public, illustrating the stark cultural and political differences between some of the states." ]
[ "This sounds like a \"polltype question\" which is not appropriate for askhistorians. sorry." ]
If looks are subjective, why are the same people (like celebrities) considered attractive by so many people?
[ "There's the basic evolutionary stuff we're all born with that dictate who's \"beautiful\" based on preferred biological mating characteristics. A woman with good size breasts and hips is considered better from a biological stand point for procreation. Her breasts show she can provide for a baby while her hips show she can birth easily. There's also lots of standards for beauty that we get programmed with by society growing up which differ from culture to culture." ]
[ "Pretty much all complex food tastes different in different conditions. Since much of our 'taste' is actually smell, I suspect that a huge amount of it depends on the proportion and composition of the volatile components. (this is certainly true for wines - consider how big of a difference temperature and glass shape can make.) Another thing is texture - mouthfeel affects our perception of flavour a fair bit. Finally, there's the possibility that some of the flavour compounds are slowly oxidized - so that means that whatever creates a flavour will be more prevalent in shredded cheese (for an oxidized compound) or the block (for a non-oxidized compound)." ]
How do stomach cells excrete HCl and enzymes through the mucus membrane?
[ "[This](_URL_1_) is a good overview of gastric mucosal physiology. There are specialized cell which secrete the HCl, and other cells which secrete mucus. The acid gets through the mucus mainly via an action of muscular contractions to help the acid be expelled from the gastric pits. Additionally, the goblet cells of the gastric mucosa also secrete bicarbonate into the mucus, helping buffer the pH at the stomach lining. The main reason for the acid is to activate the enzyme pepsinogen into pepsin, which cleaves proteins into constituent parts so they can be absorbed. Pepsin also autoactivates, meaning pepsin can activate pepsinogen into more pepsin in a positive feedback loop. The pH actually can respond pretty quickly, based on stretch of the stomach, pH of the lumen, and stimulation of the autonomic nervous system." ]
[ "Here is a good video on what you're talking about: _URL_0_ Basically the esophagus and the trachea are separated by the epiglottis. So when stuff goes down the wrong tube it means your food went down your trachea instead of your esophugus." ]
Why hasn't Magic Johnson's HIV developed into AIDS yet? Is he a rare exception?
[ "Not every HIV case develops into AIDS. Magic Johnson caught HIV right around the time the most effective treatment for HIV was developed, [anti-retroviral therapy](_URL_1_). He also happens to be *extremely* fit, which significantly improves most disease prognoses. He also has [boatloads of money](_URL_0_) to pay for his treatment. However, for the most part, pure luck. Even with all of the above going for him, he's not a particularly unique HIV case." ]
[ "Think of it like a balloon you are trying to blow up. You can start huffing and puffing with great abandon as the balloon isn't going to pop. but when it gets to certain size you start to worry, You want the balloon bigger but you worry it might go bang. So you have to slow your puffing down." ]
What was the Green Army in the Russian Civil War and what were they fighting for?
[ "The Green Armies weren't an organised force in the same way that the Reds and Whites were during the Russian Civil War, rather it's a term used to describe a number of peasant groups that resisted the Reds in defence of their communities and regions. Early in the Bolshevik Revolution, the Reds instituted a system called War Communism that called for the collection of grain and recruits to sustain the new government and it's civil war effort. In response to this forced requisitioning of supplies, Green armies comprised of peasant farmers sprung up to protect their communities and livelihoods. The Green armies were not officially involved in the political scene of revolutionary Russia, though their members and actions were anti-communist by action rather than ideology. While the Green armies constituted a reasonable threat to Soviet influence in rural areas, they petered out by the early 1920s with the end of the Russian Civil War." ]
[ "Can I request someone flesh out the Blueshirts in Ireland? From what I recall they were a right wing organisation from around the 30's- Would it be correct to say the IRA at the time were more communist leaning?" ]
Is it better to have windows open or closed on a hot day?
[ "Heat moves from areas of high concentration to low concentration. If it is hotter outside than in your room you want the windows closed. That being said air flowing across your skin helps water on your skin evaporate thereby cooling you. I don't know how to quantify the effect and it will require factors such as how much you are sweating, humidity levels, temperature differential between the two environments, outdoor wind velocity, the size of the window, the shape of the room (including possible cross breeze paths, and a whole bunch of other factors. Your best bet is to keep it closed and invest in a fan." ]
[ "AC was invented because someone wanted to remove humidity from the air, it was only after they did this they found out that a side effect was cooling. Cali. doesn't have that much humidity and Florida has a more then any human should have to go through. I would say in Florida your noticing the cooling and humidity loss, where in Cali. your just noticing the cooing (As not much humidity there to begin with). Why you feel it different i have no idea." ]
Is there anything fundamentally wrong with simulation theory?
[ "There's no such thing as simulation theory, so that's a pretty major weakness. (There are people who *say* \"whoa, maybe we're in a simulation\", but that's not the same as a scientific theory.)" ]
[ "Before I answer, may I ask who the speaker is for this particular lecture? Or if you have a link for me to listen to? I would like to know where they are coming from in their argument." ]
Why are so many people allergic to peanuts and tree nuts.
[ "They aren't, but doctors told them they were, so you can't get mad at them. A recent study found that around 80% of the people diagnosed with peanut allergies were actually allergic to pollen and not peanuts. This misdiagnosis was due to a lack of precision in common testing regimens. Link to relevant article: _URL_0_" ]
[ "\"Just about everyone here\" Where is \"here\" for you? It sounds like your question's premise is based on a small sample set based on personal observation. Before your question is addressed, you should be making sure the premise is valid..." ]
How common was atheism within Medieval Europe?
[ "'Religion' pre-Reformation is not just a belief system; it is a way of seeing the world. For a medieval person, belief in God is the same as belief in gravity or belief that your king has authority over you. This also means that in regions where religions were in conflict (the extreme North, East and South), there were more opportunities for diverse opinions on certain matters. In Icelandic sagas, for example, there are certain heroic characters who reject the influence of the (pagan) Gods on their lives and 'shape their own destiny'. However, these stories were written down by later Christian writers; it may, therefore, be very well that they projected a kind of atheism (rejection of pagan beliefs) on their characters to suggest a kind of natural state of Christianity; after all, Christian writers of the early middle ages (Gregory of Tours, for example) also called the pagan religions 'superstitio', or 'a naive belief in gods and spirits'; Christianity itself was the skeptical, rational position." ]
[ "Hello! This has been covered before on this sub.[ Here](_URL_0_) is the relevant section from the FAQ. [This post](_URL_1_) in particular from /u/idjet covers the topic quite well. To sum it up, the idea that clean water wasn't available in the Middle Ages and that people used beer or ale as a\"substitute\" for water is a myth." ]
Is there at least 1 molecule of Dealer Gas in my car after 10 years?
[ "The solution is relatively easy, as what you're doing here is no different from a serial dilution (assuming homogenous mixing after each fill up): You have 1 tank, and you're doing 1:10 dilution 520 times. This gives a dilution factor of 10^520. Your original tank of 50 L of gasoline (we'll further assume it's pure octane, since gasoline is a mixture of a large number of organic compounds) will have 35150 g of octane (density of 0.703 g / mL), which is 307.7 mols of octane. Apply the dilution factor, and you get 3.077 x 10^-518 mols octane (from your original tank) in your final tank. This translates to 1.8 x 10^-494 _molecules_ of octane. Since molecules are indivisible, you can say there is a 1.8 x 10^-492 % chance 1 original molecule remains. This also happens to be the exact same calculation for why homeopathy is BS." ]
[ "We *can* detect compounds pretty easily, thanks to technology (slightly off-topic: we know that Coke is made of water, sugar, caffeine, phosphoric acid, and caramel colour/flavourings). What we *can't* do, though, is define *how* those compounds were all produced, and the *amounts* and *methods* they were mixed together in. Was something lightly toasted? Was it freeze-dried? Was it burned? Was it softened? Was it hardened? Was it dehydrated? Was it marinated for months? Or was it kept separate? Do you boil it for 6 hours? Do you simmer it for 15 minutes? Do you keep it cold? Or at room-temperature? Do you add it at the beginning so it mellows? Or at the end so it's strong and pungent? All of these things can have a profound effect on taste, but can't be understood just from looking at the end product." ]
Was there a Roman pantheon before they adopted the Greek gods/goddesses?
[ "Just to add to the two previous comments, two sources you might find helpful would be Nancy de Grummond's [*Etruscan Myth, Sacred History, and Legend*](_URL_0_) and Larissa Bonfante and Judith Swaddling's [*Etruscan Myths*](_URL_1_)" ]
[ "I just read the article, and Witzel isn't even telling a just-so story -- he's telling an \"it's so whether it's so or not\" story. Take a look at this statement, as just one example among many: > Apart from the feature of drift, certain motifs that widely appear in Laurasian and non-Laurasian mythologies may belong to an older stratum of pre-Laurasian (and pre-Gondwana) mythology. This is in a section where he's discussing *counterchecks* that are supposed to show where the geographical boundaries of Laurasian mythology lie -- and right in that section, he says (paraphrased), \"but if those other mythologies *do* contain elements in common with Laurasian mythology, then that must be evidence of some even older shared mythology.\" Data-driven science this is not. That said, this isn't very different from what Fraser and Campbell were trying to do, so it's not an unprecedented type of overreaching (for whatever that's worth)." ]
How did the debt grow so much when the deficit decreased under Obama?
[ "The deficit is the amount by which spending outpaced earnings. So if the debt is 100k, and your deficit is 20k, now debt is 120k. As long as you have *any* deficit, the debt will go up." ]
[ "We only have 150 years worth of direct temperature readings (ie. taken with a thermometer) for the planet. There are many different proxies for measuring temperature throughout the more distant past. CO2 ratios in air bubbles trapped in deep ice cores, tree ring data, marine sediment layers, and others. All of which say, largely, the same thing. The fact that all of these different proxies tell us the same thing gives even more support for their legitimacy. In answer to the title question, the smoking gun for me at least is a graph of carbon isotope ratios in the atmosphere. One isotope of carbon (can't remember which) is preferentially selected for integration into organic material. (oil is decayed organic material) the rate of CO2 isn't just increasing, the amount of this isotope in that CO2 is way off the charts. Sorry I don't have links. [I'll see if I can find some to bolster my point.](_URL_0_) **edit** - added the answer to the title question. **edit 2** - added link." ]
Does anyone know good references for the cultural history of semen? Im specifically looking at the materiality of semen.
[ "Could you define 'materiality' please? I'm intrigued by your question, but quite confused!" ]
[ "The all-time classic on this is Bertram Wyatt-Brown's *Southern Honor: Ethics and Behavior in the Old South* (New York: Oxford U Press, 1982). Since then, a lot has been written on the subject, particularly relating to gendered notions of honor and race. One important recent work on how Southern males had the meaning of \"honor\" inculcated in them is Timothy Williams' *Intellectual Manhood: University, Self, and Society in the Antebellum South* (University of North Carolina Press, 2015), which focuses on university social life, but goes into great detail on the development of \"honor\" as a concept that was both taught and absorbed." ]
Are Vibram FiveFingers and other toe shoes really good for the health of your feet over a lifetime compared to regular cushioned shoes in our unforgiving tile, concrete and tarmac environments.
[ "Studies seems to indicate that barefoot like running could be healthier. There seems to be less stress for ankle, knee joint, and the hip joint. All negative aspects I know of are related to the transition period (I started slow in my opinion but still had hair fracture from running on cobblestones). 1. _URL_0_ 2. _URL_3_ 3. _URL_1_ 4. _URL_2_" ]
[ "Suppose you are sharing a room with your brother. The left side is yours, the right side is his. You draw a line on the floor to mark them, but you think it should be moved more to the right and so you start quarreling. You do not have a measuring tape (and besides, since the room is not a rectangle it's hard to measure), and you want to know if the division of the room is fair. What do you do? Well, some clever people came up with a way to see if the line is in the middle, and all you need is a bouncy ball. What you do is, you throw the bouncy ball against a wall (really hard, so that it bounces against the floor and walls multiple times) and see where it ends up. You do this a lot of times and each times you note whether the ball ends up on your side or his side. If you keep doing this, and the room is divided fairly, the balls should land in each side of the room about the same time." ]
Why do you hear so much more regarding desperate and lonely men rather than desperate and lonely women? Shouldn't there be more or less an equal amount of both?
[ "Women have far better support systems available compared to men. It's socially acceptable for women to feel hurt and express those feelings. They usually get ample sympathy and support from friends, family, colleagues and the public. When a man tries the same, he's ignored, ridiculed and perceived as weak." ]
[ "This occurs in sex-role reversed species, and is typically accompanied by a polyandrous mating system. Both sex-role reversal and polyandry are pretty uncommon. The northern jacana is a famous example of this. The females are more brightly colored than the males, and they defend territories that contain several nesting males. The females will mate with a male, and then lay some eggs in his nest. Females will fight with one another for territories, and sometimes destroy the nests and kill the young of other females. It should be noted that polyandry and sex-role reversal do not always co-occur. There is at least one species of monkey that is sex-role typical but polyandrous, because it takes more than two parents to take care of the offspring. In humans, limited polyandry occurs traditionally in some parts of Tibet. When resources are very scarce, two brothers will sometimes share a wife. Source: did my PhD in behavioral ecology" ]
the observable universe.
[ "Yes, but things expanded away too fast for their light to reach us." ]
[ "Nobody knows. We're still trying to figure out what crazy shit went down in the Big Bang. All we know is that there's energy now and it is conserved in the things we can observe." ]
Why did Australian Aboriginals not develop/adopt agriculture?
[ "In the book Guns Germs and Steel Jared Diamond explains a lot of history using New Guinea and Australian aborigines. One things he discusses was how farming was difficult in many geographies due to lack of beasts of burden and easily harvestable nutrient rich crops like corn or rice. There was a higher return on investment from hunter gathering than farming so it never developed. It doesn't appear to have been an economical way to expend human resources." ]
[ "Some of my uni professors in the dendrochronology lab (tree rings) at the U of Arkansas did research on this by studying the climate of the area all the way back to about 1100. The research revealed that the 3 year period surrounding the colony was the driest, most extreme period of drought in the 800 years studied. Here is a little info from NOAA on their research: _URL_0_" ]
Why do some memories remain vivid in our memory and some memories are forgotten about?
[ "For good recall, memories need to be recalled. Huh? Memories are reinforced the more they are accessed. In fact, there's evidence that when you remember something, the memory is accessed and mostly erased, then re-written. If you don't access a memory, it tends to fade away. But accessing it will refresh it and bring it back to near-original strength. The downside of this is that we don't really remember events. We remember our *memories* of the events. This can make human memory fickle, as we can introduce changes in what we remember, but be absolutely convinced that it is what actually happened." ]
[ "It's called selective focus or sometimes it's called the cocktail party effect. There is a difference between perception (actually putting brain power to interpret stimuli) and simple detection by your senses. So when you focus on this one conversation, your brain only interprets signals here and effectively ignores the rest of the sounds in the room." ]
Where fruit flies come from.
[ "Fruit flies reproduce very quickly. From laying eggs to adults in merely 8 days. This means that once you have one or two, you suddenly have an infestation. Now where do they come from. There are two options. The first is that the eggs were already present on the fruit in the supermarket that you brought home. They hatch and your have yourself fruit flies. The second is that fruit flies are small (can often travel through coarse screens) and can detect fruit from relatively far away. Like other organisms there are a few hanging around pretty much everywhere and once they detect the fruit you'll have a couple buzzing around and soon laying eggs." ]
[ "There is a very good answer to this by /u/commiespaceinvader from about a year ago: [Is it true that Hitler, Stalin, Trotsky, Tito, Freud, and Archduke Franz Ferdinand were all living in Vienna in the summer of 1913?](_URL_0_)" ]
Day of Reflection | October 13, 2014–October 19, 2014
[ "/u/idjet has done great (and patient!) work with his/her [AMA](_URL_0_) on medieval witchcraft, heresy, and the inquisition. He/she deserves our thanks." ]
[ "I had spend 2 hours writing up a long post about 3U+AB and how it would probably be a picture of that plane taken during ZG26's deployment to Greece during April-June 1941, including a cunning deduction from me showing that the plane in the background most probably is SB+GO. It was all very pretty with links to sources and all that. And then I found [this](_URL_0_) picture. So yeah, apperently someone at some point photoshoped (or whatever was used at the time) a picture taken in April 1941 over Crete on a ferry flight to make it look like it was a generic staff plane of ZG26. I would have to speculate about the reasons for that." ]
Why is it considered implausible for a piston-powered, propeller-driven aircraft to break the sound barrier, and then how does a prop setup fundamentally differ from a turbine setup?
[ "I'm not sure any aeronautical engineers think it's implausible. I can tell you why it's not been done. It gets really noisy. Basically your prop tips go supersonic and that makes for an extremely loud aircraft. The Russian bomber and the American Thunder screech both use(d) supersonic propellers. The former is apparently so loud that submarines can locate the aircraft whenever they're flying. The other reason is really that no one has cared enough to do it. It might be technically feasible, especially with today's CFD and FEA stuff being so readily available. You could definitely do a motorjet. Power density of a modern piston engine is likely comparable to a turbine from 70 years ago." ]
[ "> This recent infrared image of the Eagle Nebula shows a bubble of hot, rapidly expanding material directly behind the pillars What they have seen is the beginning stages of a supernova. The initial stages of the supernova itself happen very fast, but the shock-wave needs time to pass through and destroy the Pillars of Creation. Since the shock-wave is essentially dense gas traveling at very high speeds it will eventually push most of the PoC gas aside. But since the dense gas travels much slower than the speed of light and the PoC are enormous it will take another 1000 years for the effect to be seen by us." ]
how weather history is a valid argument for global warming.
[ "It's not 100 years of data, it's far more. A simple example is ice core samples that contain dissolved gasses, etc. that tell us a lot about the climate in the past. _URL_0_ \"An ice core from the right site can be used to reconstruct an uninterrupted and detailed climate record extending over hundreds of thousands of years, providing information on a wide variety of aspects of climate at each point in time. It is the simultaneity of these properties recorded in the ice that makes ice cores such a powerful tool in paleoclimate research.\"" ]
[ "If you want a slightly biased but accessible and interesting source for a lot of the factors that have played into this phenomenon, you should check out \"before the flood\" documentary by Nat Geo. It came out pretty recently and is really informative, while being pretty engaging. The best part is that rather than just leaving the viewer with a sense of overwhelming depression, impending doom, and a hate of humanity unparalleled since the release of Avatar, the documentary provides real, immediately applicable ways to promote change and resist the anti-science propaganda that has seemed to seep out of the woodwork of our current political administration in the US. At the very least, watch the doc's interview with Piers Sellers, a NASA astronaut with a powerful perspective." ]
is autism more prevalant these days or has our awareness & diagnosis increased?
[ "\"Autism\" encompasses a much larger spectrum than it used to. Decades ago, many people with high functioning forms of autism would've just been brushed off as weird or awkward. We now know a lot more about autism and can assign it accurately to more people. At the same time, it is misdiagnosed more often because it does encompass so much more now." ]
[ "Very hard to judge because its so subjective a question. 'people from the 1500s', for example, is a wide sample. which class? from which country / area? gender? Perhaps interesting (although undoubtedly difficult) research to undertake would be to try and find signs of depression or other related mental illnesses that characterize western society today in previous cultures and societies." ]
How does manufacturer pricing work? Can a business charge more than the price on the item packaging?
[ "Unless the store has signed a contract stating otherwise, they are free to sell for whatever price they want to. There may be some jurisdictions in which this doesn't apply, but I'm not aware of them." ]
[ "You get a paycheck from your job. They deduct a piece and pay that as taxes to the government. When taxes are due you get your total taxes owed. If they paid enough/too much (depends on your viewpoint) upfront you get money back. *Hooray* If they paid too little you have to pay taxes then. *BUMMER* *(my opinion)* Nothing is a terrible idea. It means you'll think you have more income than you do, spend too much, and will be slapped by a huge tax total and will have to pay it all in one go. Hopefully you'll have saved for that day. Get it fixed asap. Can't believe they'll let you pick nothing. Normally they should know (what percentage) how much would be good for (somebody like) you, ballpark." ]
How quickly could Egyptians write considering their alphabet was made of complex shapes and symbols?
[ "they used hieretic or demotic when in a hurry, not hieroglyphics" ]
[ "it's a problem once it's said it's mohammed  ­O /|\\ / \\ This stick figure is competely safe  O /|\\ < - muhammad / \\ This will get my head chopped off." ]
Will homemade yogurt retain (close to) the same nutrition as the starter yogurt used?
[ "No, the majority of the protein and fat involved will come from the milk you use, not the starter. The sugar content will be derived from how long you ferment the yogurt and how much of the lactose is consumed out of the milk by the bacteria." ]
[ "When programs start up, they copy a \"known good\" version of their code and resources from the hard drive, into the devices's RAM. Then the code in the RAM is executed by the CPU. If the code is misbehaving for god-knows-what reason, stopping the program and forcing it to start over restores that good set of instructions and data. And since the *entire* thing is replaced, it's good at solving almost all problems." ]
Why were prehistoric dinosaurs mean and scary looking but animals today are cute and cuddly?
[ "Read [this answer from Quora](_URL_0_). Tl;dr: Most dinosaurs probably didn't look mean and scary. The problem is that we don't have any actual pictures of them, so we have to figure out how they looked from their skeletons, and the way that we do this makes them look as scary as possible. (For instance, you know those scary Velociraptors from Jurassic Park? In real life, they were covered in feathers, and [might have been downright adorable](_URL_1_).)" ]
[ "Humans eat raw meat all the time, ranging from fish to [horse meat](_URL_4_). All food carries some risks that you'll get sick from eating it (\"pathogens\"), and various things can limit those risks, like [proper cleaning and storage of meats](_URL_0_), freezing meats to [kill bacteria](_URL_3_), and only using meat from animals that have [lived healthier lives that carry less risk of getting you sick](_URL_1_). Since animals process food differently, and get sick from different pathogens than humans do, many animals can process food that would make people sick. A good example is wild kangaroos, which are [full of bacteria that would make people very, very sick](_URL_2_), but which doesn't harm them at all. Ninja-Edit: Formatting and some 'roo stories." ]
Did the Norman invasion of England in 1066 change the way Christianity was practised on the island?
[ "To reply to your specific question: The filioque was recognised by the Synod of Hatfield in 680 under Theodore of Tarsus. It is unclear whether the Filioque was in use before that date. Sources: * Carl-Joseph Hefele: *Conciliengeschichte*, Vol. 3, Freiburg 1877, p. 252. * A. Edward Siecienski: *The Filioque. History of a Doctrinal Controversy*, Oxford 2010, p. 89. Regarding the changes the Normans brought: Those can't be underestimated. During the course of a decade almost the complete Anglo-Saxon hierarchy had been replaced by Normans. Monasteries were regulated according to the Benedictine and Augustinian rules. Clerical celibacy was enforced. In one word, the full reform program of Gregor VII. was introduced. Source: * Denis Bradley: Art. *England*, in: Lexikon für Theologie und Kirche, Vol. 3, p. 662." ]
[ "Hi there -- while we've approved this question, we would like to remind potential respondents of our [current events](_URL_0_) (AKA \"20-year\") rule -- it's fine to discuss events through 1997 (inclusive) and their effects, but not events after 1997. Thanks!" ]
Why do so many (especially modern) political dramas in film and television primarily concern plot and characters from or based on the Democratic party? e.g. Wag the Dog, Madam Secretary, House of Cards, Ides of March, West Wing, the Good Wife, State of Affairs, Boss, & others.
[ "In the case of *The West Wing*, it's because Aaron Sorkin (creator of the show) is liberal, so naturally he was writing story and characters he was sympathetic towards. In the case of *Wag the Dog* I'm pretty sure that was meant as a satire of then-President Bill Clinton, a Democrat. With *House of Cards*, frankly it's because \"evil amoral Republican\" is such a cliche (especially Southern) and making Frank a Democrat is an interesting twist. Plus, politically Frank is very much a centrist pragmatist who doesn't have much of an ideology and you're much more likely to find politicians like that among the Democrats than the Republicans. With the other ones I'm not really familiar with them, but I'll bet it's probably again because the writers are themselves mostly Democrats." ]
[ "Copying a post I made on this a few months ago: > Segregation was a major headache for the State Department from post-WW2 until the passage of the Civil Rights Act. They spent a lot of time soothing ruffled feathers of African diplomats - it was quite common for them to be harassed when travelling between Washington and the UN, particularly when passing through Delaware. Not to mention the problems organizing things like lunch meetings in segregated DC. State advocated strongly for the passage of the Civil Rights Act because of this; they argued for it as a national security issue, since the US wanted the countries sending these black diplomats as allies in the Cold War. > A source article on this: \"No Diplomatic Immunity: African Diplomats, the State Department, and Civil Rights, 1961-1964\" by Renee Romano, The Journal of American History. [You can access it free online.](_URL_0_)" ]
How does soap actually disinfect germs?
[ "And for the germ-killing (*antibacterial*) soap... Most germs (*bacteria*) are built like medieval cities, with the good stuff inside and walls (*cell membranes*) to protect them. These walls have gates with gatekeepers (*ion channels/porins*) to let only specific things and people (*nutrients and wastes*) pass. If this wall is compromised, things would be really bad. Germ-killing soap almost always work by doing damage to the walls. Some are general \"wall-breakers\", and others (e.g., gramicidin) insert arbitrary gates into the walls... so workers that were supposed to stay in goes out, and all becomes splattery goo. Ack." ]
[ "Its all CYOA. The company making the product can't advertise that it kills 100% bacertia. This is because of human error. If someone uses their product the wrong way, and gets sick, they can sue the manufacturer for false advertising, and in this society, they stupid person would probably win. Same thing with The Birth Control Pill. They say it's 99% effective because it relies on a human taking the pill everyday." ]
A gun fires a bullet at the exact moment you drop a bullet from the same height. Which bullet hits the ground first?
[ "In a vacuum, both will land at essentially the same time, depending on local topography. The reason is that vertical acceleration and horizontal velocity aren't necessarily linked. Gravity is pulling both objects downward with the same force, regardless of their forward velocity. In an atmosphere you may have air turbulence effects that slightly alter the result." ]
[ "That saying is a myth. The order you consume your drinks in is not what matters, it's the total amount of alcohol consumed. With alcohol, your inhibition goes down, which often leads to drinking more, so if you start with a drink that has a higher alcohol content, your inhibition goes down more quickly and you tend to drink more." ]
Why is there such a huge gap in the accomplishments of human species and the next most intelligent species?
[ "because we are the greatest tool makers in the animal kingdom.. It took millions of years of learning and passing down tool making before we figured out how to farm plants with our tools, once people started sitting around with free time our tools became more complex and our understanding of the world grew. fast forward another 10,000 years and Look at the tools we have, Computing, building and shaping the world around us in ways which couldn't possibly have been imagined just a few hundred years ago before the industrial revolution." ]
[ "You know when iTunes, Facebook or your phone updates and how you know it's the same program as before but things have changed slightly and you are kind of lost. Well that's what it would be like going from animals to humans with the errors being death instead of frustration." ]
Why does the DMV not accept cash or credit cards
[ "Cash is very easily stolen by people and credit cards cost fees to accept (often up to 3% of the purchase price). Businesses accept both because they want to be as convenient as possible for their customers to spend money with. The DMV doesn't care about that - you have to spend money with them regardless so they go with the least risky, cheapest way to take your money." ]
[ "They want your demographic info (age, sex, income level, etc.) so they can market their products better." ]
What is dizziness?(like spinning on a chair, then stopping)
[ "Your inner hear has circular tubes full of liquid. The liquid in these three tubes move when your head moves so you keep a sense of your spacial location. That's how you know you are falling or hanging upside down. When you are dizzy from spinning on a chair it is because the liquid in your ears is still spinning around even if your head has stopped moving. That's why it feels like you might fall down even though you aren't moving anymore." ]
[ "You could just be bored. I know I sometimes eat just because I don't have anything else to do. If your meal was mostly simple carbs, it's probably your blood sugar coming back down from the post-meal spike." ]
- What makes someone a Libertarian?
[ "Essentially, Libertarianism is an ideology based on the idea that government should play as little a role in all aspects of its people's lives, both socially and economically. It pushes for low taxes and low government spending in favor of privatization, partially on the grounds that free-market competition is a better way to ensure the quality of goods and services than government regulation. A Libertarian would argue, for example, that rather than the government deciding where and how often to re-pave roads and doing so with the people's money (taxes), the people who live in an area should decide how much they want to spend on the roads in that area and pay out of pocket for private companies to build and maintain them. Most Libertarians nowadays don't quite take it to that extreme, but you get the gist. In many cases this idea works well, in others (America's current corporate prison system is an example) not so much. **TL;DR:** Just look at [this](_URL_0_) diagram." ]
[ "Off the top of my head: * How, where, when, and by whom they were taught to write * How much practice they've had * How often they actually write by hand * What writing instrument, paper, and surface they're using * Their mental state * How carefully and at what speed they're writing * How old they are * Whether or not they're sober at the time * The purpose and formality of the writing" ]
How can electrons in Cherenkov Radiation travel faster than the speed of light if "nothing can travel faster than light" ?
[ "Particles which produce Cherenkov radiation do not travel faster than c, they travel faster than c/n in a medium with index of refraction n. There is no rule which says that this isn't possible." ]
[ "No, something being FTL would not be invisible. However, it would only be seen at a location when it arrived, or by a nearby observer after it had passed. At that point, the observer would see two images of the object, the arriving image playing out backwards, and the passing image playing out normally. It would appear quite unusual. Similarly, something being faster than sound doesn't mean it can't be heard, although you wouldn't hear it till it arrived. You'd then hear the preceding sound 'backwards' as it caught up, and overlapping any following sound if it continued on." ]
[Orbital mechanics] Does the Earth move forward in its orbit with greater velocity when the moon is ahead, and slower when the moon is behind?...
[ "No. You could say that there is a very small change in velocity of Earth relative to Sun depending on where the Moon is. Earth and the Moon orbit their common centre of mass something like [this](_URL_0_). So when the Moon is directly in the direction of the Sun (that is, new moon), Earth's orbit around the centre of mass of Earth and the Moon is going in the same direction as Earth's orbit around the Sun and thus Earth would be moving a tiny bit faster relative to the Sun. But Earth's orbital velocity around the centre of mass is about 10 m/s so it's pretty insignificant. The eccentricity of Earth's orbit causes a much bigger change in the orbital velocity throughout the year, about 1 km/s." ]
[ "Imagine pushing a cart sideways, from the middle of the broad side of the cart: the pivoting wheels will not experience much resistance, whereas the fixed wheels will have a large amount of friction. The pivoting wheels will move forward, the fixed wheels will not, and the cart will rotate. Returning to pushing the cart backwards: you will not be able to push the cart perfectly straight, and so you will generate an error in your direction (imagine the cart at a slight angle from where you are pushing it.) At this point, it is kind of like the sideways example above - the fixed wheels will experience a force relative to the ground, generating a moment about the cart. As the initial disturbance gets bigger, so will the moment, until the cart is flipped around and the pivoting wheels are in front. At that point, the moment generated will restore the cart to pointing straight ahead. Does that make sense?" ]
What are the cover charges at bars/clubs suppose to cover for?
[ "Short answer: Because they can if people are willing to pay. Long answer: Clubs have a limited number of people they can let in, usually based on fire codes. They don't want people to show up and just take up space, especially if the club is paying for entertainment. Someone who is going to balk at a $10 cover probably isn't going to buy a lot of drinks anyway." ]
[ "So, I don't know if you know this, but Blackstone did just what you are suggesting. After the housing crash of 2009, they went out and bought up homes in different cities. They put them all under the umbrella of a REIT (real estate investment trust) called \"Invitation Homes\" and then spun it out in an IPO a few years ago. $INVH is the stock symbol. Here's the website: _URL_0_ You can see from the website, they own and rent out 50,000 homes in 13 different areas. The company's total market cap is $6.7 billion. However, it's no where close to controlling a significant part of the housing supply. To do what you are suggesting, you would need just one or two companies to control all the housing in a city. I just don't see it happening. Even if you get down to 10 companies controlling all the housing options, you'll have plenty of competition." ]
Why do some objects float?
[ "Its all about density. Specifically, whether or not the average density of everything below the water line is more or less dense than water. For example, a solid iron bar will sink because iron is more dense than water, but a metal boat can float because a lot of what is under the water line is just air (because the boat is hollow). & #x200B; As to \\*why\\* this happens, consider what is required for something to sink. That object needs to push harder into the water than the water is pushing back at it. Both of these pushing forces come from gravity (gravity on the object pushes it down, gravity on the water around the object pushing the water in and up underneath the object). The amount of force gravity pushes with is just a multiple of the object's density, so if the object is less dense than water it pushes with less force, and thus can't force the water out of its way to sink." ]
[ "You were making ramen, so I am guessing your water was hot, making it less dense, that blob of oil may have just hit the water without force to break the surface tension, and sink with the help of gravity, and started to rise as the water cooled a bit and the initial impact had worn off." ]
how is that possible on Ubuntu system the video I was playing was deleted permanently but still playable on already opened video player(before I delete it It was opened)?
[ "If I understood you correctly: You had some file (avi mov) and opened it in the program. Then you have deleted the file while the program was opened and the player is still playing the movie, right? On linux system, the unlink function deletes the file from directory entry but not the file itself. It decreases the number of hard links to the file. The file on device is deleted if there is no more hard links and no program have file descriptor pointing at that file Edit: that means the file will be deleted permanently once you close the file in the player. That also means no program can reopen the file because it is not longer seen in the file system." ]
[ "in short, no, the pattern will not change. Observing in this sense doesn't actually mean observing. When people say the electrons are being \"observed,\" they really mean that they are being \"measured.\" By passing them through the slit, you are essentially measuring their position - you know that they are in the slit. The uncertainty principle states that the more we know about the position, the less we know about momentum. So once we know that the electrons are in the slit, we lose all knowledge about which direction they are going, which means they go in all directions (more or less). The idea is that at each part you have to ask what you know about the electrons. When they are emitted by the gun, you know their momentum (direction) but not where they are. once they hit the paper, you know where they are, but not in which direction they will go. Before they hit the wall, you again know their momentum (from the pattern) but not position. then they hit the wall and again you know their position." ]
What is Photon Decay / How does it work?
[ "Imagine a glass with water and sand mixed inside. If you leave it long enough, water will evaporate, leaving only sand. The act of separating is very roughly \"decay\". \"Photon decay\" roughly says that if enough time passes a photon will separate itself into smaller particles. But because it experiences no time (or go through time very slowly) the decay takes absurdly long time in our human time frame." ]
[ "I think people come to that interpretation due to Feynman diagrams since, in them, an antiparticle is pictorially represented as a line with an arrow going in the negative direction on the time axis. However, Feynman diagrams are in part just pictures to help one understand processes occurring and don't necessarily represent the exact physical interactions going on the way a Newtonian force diagram does, for example." ]
Why isn't glucose C6H12O6 and not CH2O?
[ "You're ignoring the connectivity. Glucose acts like it does because of how the atoms are connected, not just because of how many atoms of which type it has or their ratio CH20 is actually formaldehyde, which has completely different properties to glucose Chemical properties are a function of what the molecule looks like, not just what it's composed of. _URL_0_ _URL_1_" ]
[ "Because water is fairly high density, and is difficult to displace. You need a material with very low density, like cotton candy." ]
question about japans elevator to space
[ "I'm not sure why you think that. Friction opposes motion. The space elevator will be rotating with the earth and atmosphere and won't be pushing air out of the way." ]
[ "For the London Eye, they assembled it horizontally on piers before lifting it into position. [Here's a promo video on it](_URL_1_) The Singapore Flyer was assembled using steel supports, as shown in [this timelapse](_URL_0_)" ]
Why do some stars and objects in space flicker different colours?
[ "As the air in Earth's atmosphere moves, it distorts different wavelengths of light differently, and so sometimes you see different amounts of different wavelengths, causing [twinkling, or scintillation](_URL_0_)." ]
[ "Reading through your comments I realize you have fundamentally misunderstood doppler- and/or cosmological redshifting. To simplify, imagine that the speed of light is 1 m/s. Now if a source is sending out light at a constant frequency of 1 Hz, that is one period per second, what will we observe? Well if the source is stationary we will see a wavelength of 1 meter, but what happens if the source isn't stationary? Well, between each peak in the period the light source will have moved a little bit, so the wavelength of the observed light will change accordingly. If the source is moving toward you the two peaks will be closer together so the wavelength has become shorter (blue) and if it's moving away from you the peaks will be further apart and the wavelength has become longer (red). The wave itself is still travelling at the same velocity, the speed of light." ]
Is it possible that the vikings sailed in more oceans than the Northern Atlantics and the Nordic Sea?
[ "Well they certainly made it to the Mediterranean, the Black Sea and the Caspian. I do know of an example from the *Fragmentary Annals of Ireland* describing a band of viking raiders from Ireland going somewhere in western Africa, defeating a huge army and making off with loads of African slaves. It's not certain whether they made it to Morocco, Mauritania or even further south, as the Africans described are called *fir gorm*, which literally means \"blue men\" and is also the modern Irish word for black people. It may actually refer to Tuaregs who wear indigo died blue turban/veils that leech into the skin of the wearer, making them look blueish." ]
[ "I did some google-fu and found the [ship referenced on this wiki-list](_URL_2_). It pointed to two further sources. [_URL_0_](_URL_0_) which contains some information prior to German service, and the [Miramar Ship Index](_URL_1_) which has further information but requires a subscription. That list and [Wreck Site](_URL_3_) agree that fragments of the ship washed up on Navarin or Navarino Island (not sure which spelling is correct). The wreck site article also includes the name of the survey ship sent to find it, the *Bahia Blanca*. Your next step would be to consult the Chilean newspapers that cover the region. Additionally, you would need to determine if there was a Coast Guard service in place at that time or equivalent. If there was they will have a wrecking report, though it is most likely on hard copy." ]
Every decade in my mind has a distinctive fashion / music style until the 2000s - is this because I grew up in the 90s or did connectivity / the Internet merge styles into one.
[ "It's just too soon. In 2005 we didn't have a good idea of what \"90's fashion\" was (except for maybe early 90's, 1990-1991). Give it another 10 years and there will certainly be a \"2000's\" fashion and music style." ]
[ "This is a question that needs definition. What exactly do you mean by globalization? Is just movement of people, goods, and ideas? Is it important economic connections between all regions of the world? Is it thinking primarily in global rather than local terms? Until you define what you mean, the question is impossible to answer." ]
Why do circuit breakers flip?
[ "Essentially, it's a spring / clamp that trips at a given temperature or magnetic strength. As the amperage increases, the amount of the heat generated by the increase to resistance and/or the increased electromagnetic field causes the clamp to releases to trip the breaker." ]
[ "The business cycle. This is just how capitalism works--it goes from boom to bust and back. Actual hard answers are complicated bits of economics that are beyond an ELI5." ]
If a satellite remains in orbit by the force due to gravity of the Earth, and similiarly the Earth due to the sun, does the satellite not experience any gravitational force from the sun?
[ "Yes, the satellite definitely experiences the gravitational force from the Sun. That is why the satellite traces out a year-long orbit around the Sun just like the Earth." ]
[ "Very careful simulation based on testing data. Engineers have experimentally gathered data about all the different materials used to make the telescope. This data includes failure points given applied loads, vibrational frequencies, etc. They can use this along with a computational model of the sattelite to predict how it responds to the forces of launch. They design can use the results of these models to improve/change the sattelite design so that it can withstand the forces of launch. That said, It probably takes some clever engineering on the part of the mirror to make sure that forces are applied evenly to it during launch." ]
Why do we laugh or smile when we are being tickled?
[ "I don't laugh or smile when tickled, I beat the shit outta the person who does it to me." ]
[ "As /u/SwedishBoatlover has said it causes the blood in your body to increase in pH. Everything in your body, including the CO2 that you produce, exists in an equilibrium. Our bodies were designed to have certain ratios of these things in our system and it relies on them to keep everything normal. In the case of your blood pH, it is controlled by a bicarbonate buffer system. Your body carries most of the CO2 it produces in the form of bicarbonate, by hyperventilating we get rid of too much of this CO2 and that throws our body out of whack. To compensate for this our brain makes us pass out so that it can take over breathing again and the bicarbonate levels in our blood will return to normal." ]
Why does TriCare not follow with the Affordable Health Care Act rule of being under parent's insurance until your 26?
[ "Because TriCare is not health insurance, and the ACA applies only to health insurance plans. From this [page](_URL_0_): > TRICARE is not health insurance; it is a federal health care entitlement program only for eligible uniformed service members, retirees and their families." ]
[ "An example of a site is BoundTree where, once you send in the appropriate paperwork and have been verified, you can buy most everything medical. A great example is ambulance services. A doc sends in their paperwork and the ambulance's authorized user can purchase meds like epinephrine or morphine, or other medical supplies that need a script. Ultrasound machines or cardiac monitors come to mind." ]
why is Times New Roman, size 12, the most commonly used text font?
[ "For a long time, it was the default for Microsoft Word (by far the most common word-processing program), thus becoming the de facto standard." ]
[ "You probably don't remember windows 3.1.. when windows 95 came out shit was forever changed. When win98 came out, everything wrong with win95 was fixed (for the most part). Better question- why was windows 95 so good? Edit: just to wrap this question up in three simple words.. the start menu." ]
Why does my guitar pick up radio stations when it is halfway plugged in?( I get the Jesus channel.)
[ "Yessir. Without the grounding the cable and coils are acting like an antenna. Sometimes the strings even resonate. Active pickups can be even worse." ]
[ "Making some simplifying assumptions (eg friction doesn't exist)... yes, all of them become excited. This is true for 1D strings too, not just for circular membranes. To illustrate, let's model a \"pluck\" of a string as meaning that at t=0, the string at rest but is deformed into a perfect triangle shape. Then we release the string and see what happens. The triangular pluck function we just described has a Fourier decomposition (I'm assuming you know what that is based on your use of vocabulary): it can be represented as a sum of infinitely many sine waves. Since each of these sine waves is a mode of the string, each of those modes get excited. The amplitude of each excitation doesn't change over time, and is simply the magnitude of that sine wave in the original pluck's Fourier decomposition. The higher modes don't have infinitesimal amplitude, just very small: the sum of the squares of the amplitudes needs to be a converging series." ]
Why aren't we stimulating our pleasure centers with electricity?
[ "An experiment was done in which rats had electrodes connected to the pleasure centers of their brains. When researchers activated the electrode by a lever that the rodent could push, it would press the lever as much as 700 times per ~~minute~~ hour. It would prefer pressing the lever over food and water, eventually dying of exhaustion. _URL_0_ You see similar behavior in humans addicted to methamphetamine. Nothing seems to matter except their next fix, and they will forego food, water, sleep, and hygiene to get it." ]
[ "So, if you had a robotic tickling arm that you controlled with a joystick, could you tickle yourself?" ]
Biofeedback Coherence / HeartMath. I was given a device to "help" with my anxiety and depression and I am skeptical that it does anything meaningful. How does it work and How does it produce long-term results beyond simple breathing / meditation techniques?
[ "[It is garbage.](_URL_0_) The field of psychiatry is still emerging and there is a huge amount we don't know about how the brain works. However the use of meditation as a calming influence (practicing focus and being calm on demand) is mixed up with spiritual woo (access a higher level of consciousness and channel your \"healing energy\"). Sorting effective techniques from quasi-religious bullshit is tough. So yes, your skepticism is warranted. I would suggest looking into better medical services rather than pseudoscience if that is an option for you." ]
[ "The Big Bang theory actually concerns itself with the evolution of the universe since moments *after* whatever initially happened. If we try to use the theory to extrapolate from the first moments it *can* represent to the actual beginning of time, the equations give us a singularity - basically, a divide by zero. What we don't know is whether these kind of singularities are something physically existing (though we're pretty sure you can't actually divide by zero), or whether the model is simply incomplete and gives totally wrong results when applied beyond its scope." ]
Why do so many people catch lobsters out of the ocean. Isn't it easier and cheaper to raise them in a farm?
[ "As I understand it, lobster larvae take a long time to mature, as well as requiring a lot of food. But a more likely reason is that there was never a need to because of the massive lobster population off the coasts of places like New England. Only in recent years has the lobster population began to rapidly decline. I remember hearing somewhere that in the 1700s they had to make laws prohibiting slave owners from feeding slaves lobster more than 5 days a week due to how easy it was to get. (citation needed)" ]
[ "The media in which the film's where originally captured in has higher quality then the old video tapes or even digital copies could produce. High definition releases of old movies captured on actual film (none of this applies to film captured digitally) do actually capture more detail then older methods could." ]
Are there any known instances of viruses in non-lethal relationships with their host?
[ "Yes actually! The example I know of though is not that simple. In the case of panic grass in Yellowstone Park, there is a fungus that resides in the roots of the grass. If the fungus harbors a particular virus, then the plant will be more heat tolerant than without it. The plant (and fungus) can survive without the virus, but it can survive higher temperatures in the hot spring areas with the virus. [Here](_URL_1_) a few [readings](_URL_2_) that you [might](_URL_0_) find [interesting](_URL_3_)." ]
[ "Sort of how hawaiis volcano is not particularly dangerous as it constantly and very gradually errupts. Good question, i would love a geologist to point out all the unidentified variables etc" ]
How do dogs in movies and TV shows know what to do? How are they trained?
[ "Dogs are, the same way as children, given very easy instructions. You hope to get it done, and reward them for doing the right stuff. It's also about tricking them into thinking the scenario is real. If you want a shot of a class of children all crying for your movie, it's not unusual(to be loved by anyone) for someone to scare them all, or yell at them. It seems harsh, but it works. Dogs can be triggered the same way by seeing their owner, or a special caretaker get \"hurt\" etc. on set." ]
[ "Most of the interior filming is done in Highclere Castle, aka the Abbey, with the exception of some sets which were built in studio. Considering that most shots are done in actual historical places, it's possible that they aren't allowed to film smoking shots indoors due to the preservation of the houses. However, you can see some of the servants smoking outside, which is more accurate to the period. People did smoke back then, upper classes included, but due to historical preservation laws when filming they might not be able to." ]
why is it that certain companies in the uk are called one thing, but elsewhere called something totally different?
[ "I'm pretty sure each country has its own laws regarding intellectual property and trademarks, there's no international collaboration. So if an American company that trades under the name \"super duper burgers\" wants to expand to the UK and finds that there is already another company trading under that name they are square out of luck and have to pick something else. So they will trade in the UK as \"burgers that are super\" while being identical to their US counterpart." ]
[ "The countries in the Universal Postal Union have agreed on common standards. If I pay the proper international postage rate in the United States, then any postal service will deliver to the proper address in their country after receiving the letter from the U.S. Postal Service, regardless of the local postage rates. Similarly, someone from abroad is not affected when sending a letter to America if U.S. postage rates go up. The only trick is the proper addressing, since that does vary wildly by country. But you can find the recommended addressing scheme for each country on the Internet." ]
What types of persecutions do white men face in the U.S. (specifically)? Why are they defensive when dealing with issues like rape, police brutality, racism and online harassment?
[ "Because most of us know that we were born into all these issues caused by long-dead white men. Sometimes it feels like a direct attack on white people because we are \"white,\" which is a pretty huge category. ELI5: Nobody wants to be criticized for being in a group when they had no choice and nobody wants to be blamed for something they had no part in. It sometimes is hard to get past the immediate \"that's not me\" response in order to look at larger issues." ]
[ "In the country of Rwanda there were different groups of people. One was called the Hutus, and the other was called the Tutsis. The Hutus didn't like the Tutsis because the Tutsis had more money, and always bossed the Hutus around. Then one day the French government which was was in charge of Rwanda tried to allow the people to vote for their leaders. The Hutus had a lot more people, and they all voted for the same people. The people they voted for were Hutus, and passed laws that discriminated against the Tutsis. Then when the president was on a plane it was shot down. All the Hutus blamed the Tutsis. This atmosphere of hate built up, and eventually on the radio there was talk of killing the Tutsis. Propaganda started to be spread, and eventually groups of Hutus organized raids in Tutsi villages. They Hutus would go in, kill any Tutsi they saw with a machete, and would rape people too. Sorry I don't know how it ended." ]
How can scientists truly claim that distant stars contain trace amounts of elements such as tellurium
[ "Background interference would be minimized in the same way it always is in spectroscopic experiments: by using a blank sample. In this case, they would aim the Hubble at a point next to the star and take a blank reading. Then they would aim at the star and take their experimental reading. By subtracting the blank from the experimental reading a meaningful spectrum is obtained. Repeating this process across multiple blanks and stars yields statistically viable data." ]
[ "All the time our cells get damaged and dies. New cells are created in order to replace them. Every time cells copy and duplicate themselves they have to copy and duplicate the DNA, too. The DNA is ordered in sequences called chromosomes. When a chromosome is duplicated, a short sequence of the DNA at its end gets cut off. The ends of chromosomes have some dummy DNA called telomeres. When all the telomeres have been consumed the cells can not duplicate themselves anymore. There is a special protein called [telomerase](_URL_0_) which adds extra telomerase to the end of chromosome. The protein is usually active only in stem cells. If it gets accidentally activated in ordinary cells, the growth of cells may result in a cancerous growth." ]
How common were Blacksmiths and what was their primary job?
[ "Blacksmiths made tools such as axes, hammers and the like. They also made nails, screws and other fasteners before machines were invented to make such things. And they made horseshoes, repaired wagons. Basically a blacksmith was a machine shop and vehicle repair shop in the pre-industrial world. Edit: there is a /r/blacksmith where you can learn more about things blacksmiths can do. It's pretty interesting." ]
[ "This sounds like a \"polltype question\" which is not appropriate for askhistorians. sorry." ]
What was the "Universe" before the big bang?
[ "This has already been answered numerous times: [_URL_0_](_URL_0_)" ]
[ "Nothing!!! really, there is nothing there. Just the fields - the electromagnetic, gravitational, higgs and probably many that I don't know about and humans have not yet discovered - from which the particles are created and in which they interact." ]
How did non Latin based languages like German, English and Swedish end up using the Latin Alphabet?
[ "Latin was the language of western Christianity. When the Church spread through these regions they took Latin and its alphabet with them. During the Middle Ages, especially the earlier portion, priests and monks served in administrative roles maintaining the majority of written records--both in Latin and otherwise. They also had a significant role in education so when people learned to write, both in Latin and in the local language, they used the Latin alphabet." ]
[ "Alice wants to send a message to Bob. They are very far away. So, she writes a letter and gives it to Chris, who is a very nosy individual. Chris steams the envelope open, reads the letter, and then reseals it and hands it to Bob. If you are Alice and Bob, you probably don't want Chris to do that. So you develop an \"inside language\", an encryption code. Now, Alice can write in this code, and she knows that even if Chris opens the envelope, Chris has no idea about what is being said in the letter. When Bob reads it, he will get the message just fine. Replace Chris with governments, advertisers, your employer or your parents..." ]
Are Filipinos Hispanic?
[ "Some of them are, but most are not. The term \"Hispanic\" as it is used in the United States is a little made up, a creation of the Census Bureau. It requires that persons \"trace their origin or descent\" to a Spanish culture; theoretically, they could be from anywhere in the world. Most Filipinos do not identify as Hispanic, and it does not make much sense for them to do, since most do not speak Spanish and have little connection to Spanish culture. In ordinary parlance, the term is really only applied to people from the Spanish-speaking Americas. People from Spain are more likely to identify as Spaniards than as \"Hispanic\"--but they technically meet the census definition." ]
[ "A follow-up question for any historians of South-Asia: Was this colorism ever noted in Vedic/classican Indian sources? How old is this bias?" ]
The American Healthcare system.
[ "All I can say is that there are Americans, such as myself, who are incredibly embarrassed by it." ]
[ "I wouldn't base your opinion on the TTiP from what you're told on Reddit. These kinds of agreements are very complex and to understand exactly what they mean is no easy task. People like to take sections of these document out of context and write off all of the benefits. I'm no expert. But neither are the people on Reddit. Have a look on Google and find some reputable sources that explain several view points." ]
In the middle ages how did they picture what was ancient Rome
[ "Hi. While questions are always welcome, I think you should see one of our older threads: * [How were Roman ruins perceived in the medieval period, if at all?](_URL_0_)" ]
[ "There isn't much good material on the Carthaginians which makes writing about them a challenge. The only sources we have for them are Roman and Sicilian, and they both hated Carthage. A book you might be interested is *Carthage Must Be Destroyed* by Richard Miles. He discusses the political factions of Carthage." ]
Why is that when you blow a balloon too hard, little air pockets appear inside your mouth just below your ears?
[ "There is a tube between your inner ear and your mouth to help equalise pressure between the two. They are called the [Eustachian Tubes](_URL_0_). If you blow too hard and have too much pressure in your mouth, the tubes will relieve some of that pressure to come out of your ears. I believe this is what you're looking for? Not 100% sure." ]
[ "There's no hole being made. Think of it as the same thing as a swimmer in a pool of water. The closest thing you can do to \"making a hole\" in the water is, like, belly-flopping into the water...but the cavity made by the body entering the fluid only exists for a tiny amount of time. To even call it a \"temporary hole\" would be ridiculously generous. The water rushes back into the cavity instantaneously. Remember that air and water are both fluids. When an object passes through the air (any part of the atmosphere), it disturbs it, creates eddy currents, moves it around, creates zones of high and low pressure in a very localized area...but there is no such thing as \"making a hole\" in a fluid. That is fundamentally not how fluids work." ]
How do predators eat poisonous spiders and not die? I saw on the TV a big spider eating a poisonous black widow, isn't that suicide?
[ "To be specific, these spiders are *venomous* which means the toxin is intended to be injected into the tissues of the unlucky victim. In some cases, venom does not achieve the same impact if ingested. They may be diluted in the stomach, less able to penetrate to the tissues where they can do harm, and the hostile environment may even break down the critical substances that give the venom its potency." ]
[ "Fly physiology is so completely different than our own that any comparisons outside of genetics or general cell biology are pretty difficult to make. The fact of the matter is that flies have all sorts of their own pathogens. Because their physiology is vastly different, the pathogens on flies rarely affect humans, and human pathogens have little effect on flies. For example, many human pathogens exploit cell division or cell division machinery, but most parts of the average fly are postmitotic. Furthermore, flies are actually adapted to eat bacteria and mold. Experimental fruit flies generally need yeast in their nutrient media in order to survive and reproduce effectively. [Here's a very old paper that examines yeast digestion in fruit flies.](_URL_0_)" ]
Modern humans have existed for about 200,000 years. If you could go back in time and bring back an infant would it be able to grow up and thrive like a baby from this day and age?
[ "By all measures, a large part of our \"modern\" culturo-cognitive faculties existed 200kya, while the systems that gave rise to them did not. Taking out disease and immunities from the equation, a newborn from day 1 raised as \"normally\" as possible and being acculturated no differently than any other child (relative, I know) would probably be as successful as anyone else. The only debilitating factors are to the extent that they try. Remember: when we're discussing ancestors from 200kya or older, we understand them relative to the next benchmark in progression: abstract thought beget art, etc. because we're tracking their progression towards what we understand as \"human\" but if you skip all the steps in-between and put a \"culturally-sterile\" infant in a loving home, there would probably be no discernible difference." ]
[ "_URL_0_ Babies look too similar to (grown up) people, but not exactly like them and it makes them gross for some people." ]
Why isn’t possible for all cars to move in unison when a red light turns green instead of seeing a green light and having to wait a few seconds before you can move?
[ "It's to do with the spaces between the cars. At the lights there's only a small gap, and if all the cars started together then the gap wouldn't grow and if someone hits the breaks there would be an accident. By waiting a second for the car in front to move, you create a safe gap between your car and the car in front." ]
[ "Each builder is going to do what they want. Google pictures of Beijing some time, they have entire large blocks of buildings the same style and height. They also are far more regulated about how they build. I imagine in a more free market economy, each builder wants their building to be \"their building\" and not like another one. Plus each builder has a plan, purpose and marketing approach to create a profitable building, and that's going to differ from developer/investor to developer/investor. You'd have to ask an engineer, but another short answer is the materials and design of the building will also dictate what is optimal. So again, with each design being different, making the building as tall as another building is just not going to even make the bottom of the priorities list for the engineer/builder/investor/developer teams." ]
What effect would a tennis ball sized ball of matter have on the earth if it was fired at such a velocity from orbit that it passed through the earth at one side and out the other?
[ "There is no such velocity. Projectiles at high speed will only penetrate about a tennis ball's diameters length into the ground. Here's a good picture: _URL_0_ Basically, if the densities are comparable, then you don't get much penetration." ]
[ "The problem is that the waste heat will always outweigh the temperature decrease from the ice. Its the same reason a refrigerator with the door open won't cool your apartment. The net effect would be to convert solar energy to heat. A more viable way to redirect solar energy is to put reflective particles such as ash in the upper atmosphere, which could reflect light before it is converted to heat in the atmosphere." ]
(For DIY) Why is it more common to paint (house) wall with paint rollers but use spray can for cars?
[ "If you google \"rustoleum roller paint job\" or the like, you'll find plenty of people who have rolled a paint job on their car for ~$50. With the right kind of paint, some thinner, time, and patience, it can totally be done. The hardest parts would be getting in all the tight spaces a sprayer would do better, and highly irregular surfaces where you can't apply an even amount of paint, particularly around the front grill area. The technique is prone to drips and runs. Spraying is inefficient due to overspray, expensive due to equipment, and hard because you need a fair amount of technique and practice to get it right, but it's also fast and works on all the nuanced surfaces of a car. You can also spray rustoleum, if you'd like. You don't have to use expensive automotive paints, and you can roll the expensive automotive paints if you want, you just have to blend the chemistry different so the paint bucket doesn't go solid on you in the time you're going to spend rolling." ]
[ "A \"regular\" download is one person (you) downloading from one location (the server). This allows for a secure connection but is limited by the server's upload speed. A torrent is one person (you) downloading from many locations (everyone else who is \"seeding\" the torrent). This is called a peer-to-peer network. This does not allow for a secure connection, but because a lot of people are uploading, you can download much faster . Pirated content primarily uses torrenting because it is; A) Difficult to trace to a single source, which maintains the anonymity of the initial uploader, and B) is anonymous by nature for the downloader and all subsequent uploaders. This anonymity is important due to the *illegal nature* of the act." ]
Why are the mirrors on the newer telescopes shaped like hexagons?
[ "Disclaimer: amateur astronomer. I have a clue, but no guarantee that I'm right! In the past, large telescopes like the 200\" at Mt. Palomar would be just one large circular mirror. When you try to scale up much beyond that, you get problems like the mirror sagging under its own weight, ruining the image. The modern multi-segmented mirrors are a workaround to this problem. I believe that the hexagonal shape of the mirrors is simply for most efficient packing, getting the most surface area within a given overall diameter. The first big multi-mirror scope, the MMT in Arizona, used 6 circular mirrors, and if you look at pictures of it, the wasted space really jumps out at you." ]
[ "SpaceX has two types of rockets in that aspect: The regular cargo version with a payload and the Dragon version - Dragon is the capsule that flies to the ISS (cargo, soon crew as well). I guess you mean the cargo version with its wider payload fairing. The diameter of the main rocket was chosen to keep them small enough for road transport. The payload fairing at the top is wider than the rest of the rocket to have more space for satellites. Many rockets use this design - [Atlas V](_URL_4_), [Delta II](_URL_3_), [Minotaur-C](_URL_0_), [Soyuz 2](_URL_1_) and [the Indian rockets](_URL_2_) have it as well, for example." ]
(X-Post from r/AskReddit) Any internet historians out there? What was the early internet like? What did you do on it? How would you describe the "internet culture," if there was one?
[ "A mod clarification as this question is rubbing right on the edge of our 20-year rule: feel free to talk about what the Internet was like **prior to 1993** (yes, there was an Internet prior to then!)" ]
[ "Is there a specific region and time period you are interested in? If not, your question would break our \"poll type\" question rule." ]
How is it that a single boil on a body causes feverish symptoms but acne all over the face/body does not have that cumulative effect if they are both infections?
[ "Acne is typically caused by clogged pores, not necessarily infections, although some infections might contribute. That being said, acne/boils are symptoms of a problem and not themselves the 'cause' of the problem, so the \"number of skin disruptions\" is not necessarily indicative of how dangerous the underlying illness(or lack thereof) may be." ]
[ "There aren't any answers on here that are correct. Bruce Schneier has a good write up on it at _URL_0_. While it focuses on terrorism, terrorism is just one specific crime. The principle is the same for all crimes. The short of it is \"base rate fallacy\". Since any algorithm for detecting crime is not 100%, there will always be false positives. When you look at the number of false positives versus true positives, the false positives are far more likely to occur. So you spend the majority of your resources on false positives (assuming you go after all cases). Obviously, you can't go after every case. So you can only go after a much smaller number of cases. You will be more likely to be investigating false positives and probably won't have a true positive in the group you narrowed it down to. TLDR - math says you will have too many false positives and you will most likely never investigate a true positive." ]
Why do we hate weak or limp handshakes?
[ "To me, if there is a weak grip and lack of eye contact it conveys a lack of engagement in the meeting. Feels like they are subconsciously saying \"meh\" about meeting me. When it is the opposite, the way it should be...firm grip, good eye contact it conveys confidence and mental engagement in the current situation. It would make quite an interesting social experiment!" ]
[ "\"Just about everyone here\" Where is \"here\" for you? It sounds like your question's premise is based on a small sample set based on personal observation. Before your question is addressed, you should be making sure the premise is valid..." ]
Why did we really choose to put year Zero where it is currently set?
[ "There's no year zero... the dates go directly from 1 BC to 1 AD. And, the current system of dating years from the date of the birth of Jesus Christ was created by a religious scholar in Rome in the 6th century AD." ]
[ "A common old expression in business is \"one throat to choke\". It means that when things go wrong, you want one individual, not two or some group or committee, that you can point at as accountable to fix it or accept accountability and any recompense for the problem. It's a lot easier to do it with an individual than with a group, because people in a group can then blame each other. People naturally just want one responsible person for stuff. And a very simplistic way of looking at American political power is the President is the one single guy with the final say in stuff through his veto power. He's the one with \"The Buck Stops Here\" sign on his desk. So unlike the big hard-to-understand mass that is the Senate or Congress or State political structure or municipal political structure, Obama is that ONE guy who easily gets the finger pointed at him... or just given the finger, depending on who's gesturing." ]
Why can't I brew a cold tea?
[ "That simply is not true. Put your teabags in water. Set on counter. Come back tomorrow and pour a glass of tea. Add ice and lemon and / or sugar to taste. Enjoy. You will not extract as much tannins this way so it will be smoother than tea made with boiling water." ]
[ "very simple, Air is a horrible transfer medium for energy, Water is a good tranfter medium for energy. It takes longer for the energy in the air to flow to the ice cube then the energy in the water to flow in the ice cube, When when there is steam in the air, its still maybe 50% humidity compared to 100% humidity in water. TL;DR energy flows better through water then air." ]
Reasonably Accurate Prehistoric Fiction?
[ "You might like Sarum: The Novel of England by Edward Rutherford. It's set in a single location and spans prehistory through the 20th century." ]
[ "Just a heads up: archaeologists study people, not dinosaurs. You want a palaeontologist. You might want to change the flair on your post." ]
Does the co-pilot have any control over the plane?
[ "He has as much physical control as the pilot does. There are two sets of controls, one in the left seat (pilot), one in the right seat (co-pilot). Authority wise, he is not the commander of the aircraft, either legally or in corporate structure, but he can certainly physically control the airplane from his seat." ]
[ "I know Air travel and contrail contribution to cloud clover definitely changes surface temperature in cities. In the 3 day stand down of (almost) all air traffic in the days following the 9/11 attacks, there were measurable decreases in surface temperature . I can only assume the effect would contribute in other measurable ways in terms of weather patterns. Hard to get actual measurements in real time though as you’d need an odd scenario like the stand down to measure the absence of its effect." ]
Why does the moon sometimes appear sideways?
[ "It's a lot easier to grasp when you think about the Sun's location relative to the moon when you're looking at it. The bright part of the moon is always facing the sun." ]
[ "Imagine they take away your chair in kindergarten class. They make you stand there all day and never sit down. Imagine how tired you would be after all day. Not what if you forgot to go home from school and stayed there all night too!!! Well, the muscles holding up your perky little face and eye lids gets tired too, and after a long day, wants some rest. So it droops down a relaxed a bit, but then the blood has a harder time flowing through, and gets all stuck up under your eye for a little while, making it darker" ]
During colonial times, why did the British Empire more or less ignore South America and instead focused on North America and the Caribbean?
[ "hi! hopefully someone will drop by with an in-depth explanation re the British, but you can get started on a brief summary here * [Why did England focus its colonising efforts on North America (When the Spanish and Portuguese focused on South America)?](_URL_0_) and this post may be of interest if you want more on the Treaty of Tordesillas * [Why is Brazil the only lusophonic country in South America?](_URL_1_)" ]
[ "The US has one of the largest populations in the world. The US is #3 behind China and India. The US is also one of the richest countries in the world. We've got twice the population of Russia or Japan and nearly 4x the population of Germany, the other large wealthy (ish) countries. A large, rich population with lots of discretionary income means that they're going to spend a bunch of money on entertainment. English is also a big help. Every American & many people around the world speak it, so you can make blockbuster movies with huge budgets and expect people to watch them. If you compare this to India or China, they might have larger populations but they have less money to spend and movie producers have to worry about having dozens of different languages limiting the audience for a movie." ]
Why is it better for you to eat 3 separate meals instead of snacking all day?
[ "It's not really. Bruce Lee ate 5 smaller meals a day. Our ancestors would graze lightly and then have a larger communal meal around the hearth at night. Hobbits eat around 6 meals a day, not including snacks. Three meals a day really just fits into our busy lives. It became the norm as we become more industrial and had to find time to eat during our busy day. So long as you're getting the nutrients and calories you need, there is no reason to eat three squares a day." ]
[ "How big are the files you are talking about? You may have noticed that transfer speed always ramps up slowly. Therefore it will always be faster to transfer one 10gb file than a hundred 100mb files. This is because the file system needs to open a data stream of the file, read the data, write the data, close the stream. The more files you are transferring, the more actions need to be taken. If you transfer a lot of small files over usb3.0 you will almost never make use of the full transfer speed that it supports, because it just doesn't have the time to ramp up to that upper limit. Maybe someone can expand on this. Im just a hobby programmer with some knowledge of this." ]
How is Bernie Sanders' free tuition plan a success when all of the affected citizens are currently below the voting age?
[ "Parents of children and teenagers also like the idea of not needing to pay tuition for their kids, or of their kids not being crushed under ridiculous student debt." ]
[ "They don't. It's a marketing ~~lie~~ gimmick. I used to work for a company that did a similar thing by mail. New customers were supposed to sign up by a certain time for special rates but as a specific matter of policy we'd give those rates to *anyone* who mailed back the special offer." ]
So you know how some animals can “smell fear”? Well, I was wondering, do humans actually emit a scent when they’re afraid, that other animals can smell?
[ "We know that pheromones are used by other species to influence certain social behaviors. For example some wasps emit pheromones when under attack to signal other bees from their colony to come help. Humans have pheromones too. Their effects on human behaviors are not fully understood, but it is conceivable that other animals may be able to sense them, consciously or subconsciously." ]
[ "Mosquitos are attracted to us by the heat and sweat we produce, typically it is only the females that are attracted to us. This is because she needs our blood to feed her offspring, thus the only way to make us not attractive to the female population of mosquitos is to mask this. The repellent is known as DEET (not it's chemical name) which basically makes our skin a nasty smelling place for mosquitos." ]
What is the total population of all life on our planet?
[ "Do you count bacterias? The rest of the animals are just a rounding error for the bacteria population." ]
[ "I think you'll wait a long time for a sensible answer to this one. I don't think anyone knows." ]
Varying answers about credible, non-Biblical sources that verify Jesus Christ's existence.
[ "There's a lovely section in [the FAQ](_URL_0_) that has some answers." ]
[ "I know journals give a good representative of the top historians in WWII history, ANE history and Ancient Roman. This should be the case for other fields of history. For someone to publish several works in a peer-reviewed journal, they have to be serious and very prolific in their fields. Journals are a good place to start your search; find journals that publish for the field of history you're interested in and go from there. Also, you can randomly select 10 journal articles on the subject of interest, and see who are the most cited authors across the board." ]
How were the farmers who owned the land that became battlefields on the Western Front compensated?
[ "As a follow up question, how are the farmers/owners of that land compensated today? Battlefields of WW1 are still claiming victims and damaging property with exploding ordinances. Wouldn't this not be covered under insurance as acts of war are pretty much never covered? Or is there a special fund or type of insurance these landowners can purchase/use? Since there are still unexploded ordinances across many of these former battlefields, how big of an issue or concern is it for the general public in these locations?" ]
[ "In *[Plague, Fear, and Politics in San Francisco's Chinatown](_URL_0_)*, Risse provides the following in reference to practices and attitudes in China at the time: > Most villagers, however still practiced the instillation of a powder made from dried smallpox scabs. Instead of conferring immunity, this strategy often triggered full0blown cases of smallpox. Chinese called the disfiguring facial scars \"flowers of heaven\" and considered them a mark of strength and seasoning. Although local [San Francisco] residents found pockmarked Chinese repellent and dangerous, the immunity proved advantageous in California…\" While perhaps not desirable per se, that's still a slightly more positive view on the scars. That may be what you recall having read, though perhaps elsewhere. Hope that helps. * Risse, Guenter B. 2012. *Plague, Fear, and Politics in San Francisco's Chinatown*. Johns Hopkins University Press" ]
How come you can say "take me to church" or "take me to school", but it's "take me to THE store, THE zoo, THE mall"?
[ "There are two things going on here. Typically, people only have one home, one church, and one school, so these words can be without articles. Other words require them. When a word requires an article, \"the\" can be understood to refer to a default choice understood by both the speaker and the listener. \"Let's go to a Chinese restaurant\" means any available Chinese restaurant, probably the closest one. \"Let's go to the Chinese restaurant\" means the one close to where we live, the one we go to all the time. Put those together, and you have: * a - any particular place * the - the primary, default place, as oppose to others * (no article) - a singular place" ]
[ "If you ask for 1 pen, it costs you two dollars. If you ask for 100 000 pens, they will only cost you one dollar each. I prefer selling you 100 000 pens at half price, than selling you 1 at full price and have 99 999 sitting around doing nothing. In a similar way, if you ask for a small amount of money, you pay a big interest, and if you ask for a big amount of money, you pay less interest. The bank actually wants you to ask them for a LOT of money, so they lower the price the bigger the loan is. Loans is where they get their profits from." ]
If you hurt yourself why does shaking that part of your body relieve the pain?
[ "This phenomenon is called the *\"Pain Gate Theory\"*. When you injure yourself, pain signals travel from the site of injury to your brain. When you do something else to that part of the body, for example rubbing it with your hand, this also sends signals to your brain. However, because both signals are coming from the same part of the body, only one signal can \"enter\" your brain at a time. And this can be thought of as a gate. The **gate only allows one signal at a time**. And it just so happens that other stimuli such as pressure, vibrations, touch, etc. have priority over the incoming pain signal. You feel less pain because you are interpreting other signals form the injured body part, instead of the pain Hope that helps. Source: Medical Student" ]
[ "Your evolutionary ancestor is calling for help, frightening the enemy, and moving you a bit away from the danger while your brain can catch up and decide what to do next." ]
What is happening with the US gov't shutdown, part deux
[ "**Are DoD Employees working again?** Yes, and No. A large portion of DoD has returned to work, based on the legal interpretation of POMA [(Pay our Military Act)](_URL_51_) by the Secretary of Defense. In short, civilians that are considered to be \"helping/supporting the military\" were told to report back to work and have been promised pay for their work until funding under POMA runs out, or congress passes a CR to fund the government. However, congress has not passed any law/act that provides for backpay for civilians who were furloughed during the first week of October. Further, there are still a handful of civilians in DoD who are under furlough and are not being paid right now." ]
[ "We ask that answers in this subreddit be [in-depth and comprehensive](_URL_2_), and highly suggest that comments include citations for the information. In the future, please take the time to better familiarize yourself with [the rules](_URL_1_) and our [Rules Roundtable](_URL_0_) on Speculation." ]
Why are there so few engineers and scientists in politics?
[ "for the most part, the work i do is a whole hell of a lot more interesting." ]
[ "I'm not normally one to naysay a request for knowledge, but this is not exactly a topic that can be explained like you were five. It requires a fairly extensive level of prior knowledge and understanding just to pose that question, and any answer posted is likely to be incomplete, wrong, or misleading. Sorry, but this is not the proper subreddit for this. Good luck on your studies though, and from a recent IA/poli-sci student to another, good luck finding a job when you graduate." ]
Guide dogs for the blind, how do they know where to take someone?
[ "They don't know, unless they have been specifically trained for a certain location. Guide dogs work on a veto system; the blind person walks wherever they want and the dog will stop them if it is dangerous. The dog for example wouldn't particularly want to cross the street but the owner would, and when they came to the street the dog would stop the owner from walking in." ]
[ "They pretty much don't. However website owners have the option to tell Google \"hey, I have a site here, check it out!\" When pages don't link to each other, website owners have the option to host a special file, named *sitemap*, that does list all content that should be searched for." ]