Subset (10)

eli5 · 25k rows

Split (1)

train · 25k rows

query stringlengths 20 300	positive listlengths 1 1	negative listlengths 1 1
What is the earliest accredited invention?	[ "Could you clarify what you mean by \"accredited invention?\" Do you mean the first first piece of technology that we can clearly identify as being invented by a human, or the first piece of technology where we know the name of the person who invented it?" ]	[ "The Maine Penny is the southern most artifact found that is verifiable. [reddit!](_URL_0_)" ]
when a celebrity dies (e.g. Jose Fernandez, Prince, etc.), why is releasing the medical information about their death not a HIPAA violation?	[ "Death, and cause of death, is public record. Also, the family or other loved ones are free to share whatever they may know." ]	[ "Influenza is described as being transmitted by droplets. Small single center studies have shown that the flu virus can be aerosolized and be detected by PCR, but cannot be detected by culture. In addition, studies have not shown a superiority of N95 masks over simple masks in transmission of the 'flu in healthcare...
why does cold water feel awful on our bodies but warm/hot water feels so good ?	[ "Probably because the change in temp is less severe. 120 degree water is closer to your body temp than 50 degree water." ]	[ "Most animals spend a lot of time cleaning themselves, by for example licking themselves. Humans apparently don't like licking themselves, so pretty much their only option is to go in some water. Also, fur often takes more dirt to look dirty than bare skin, since there are many layers where the dirt can go unseen" ...
What the fuck is a "neckbeard"?	[ "Picture Abraham Lincoln. He had a neckbeard. The more common term for neckbeard amongst the general public is chin curtain. Neckbeard is probably more appropriate for young adult males who can't grow a full beard yet, but allow stubble to accumulate to the point that the most visible hair is on the chin and neck. ...	[ "Top = amount of upvotes-downvotes New = time since posting Hot = how fast something is getting upvotes Controversial = a ratio of downvotes to upvotes" ]
Solving a Rubik's cube	[ "You can learn it quite easily by following some of the tutorials on YouTube - I learned to do it without references in a couple of hours. It takes NO skill to just solve it - doing it really fast though, is something else." ]	[ "Google's _AlphaZero_, trained solely by reinforcement learning from games of self-play, took 4 hours to beat the previous world champion chess program, Stockfish 8. [Paper](_URL_0_). (PDF)" ]
Why do humans have such distinct hairlines, as opposed to all over the place like other animals?	[ "All human body hair covering falls under two categories: either the hair is located in places where it helps to reduce friction (armpits, inner thighs, around the nipples, etc...), or in areas where there is a large amount of heat transfer (specifically, the head), and exists to regulate temperature. To answer yo...	[ "Setting aside the terminology of \"race\", it's entirely down to selective pressures of the different environments. In equatorial regions where the sun is plentiful, having a lot of melanin is useful in protecting against cancer. The further north/south you go from there, the less sun there is, so having less mela...
Why is String Theory's discovery said to be an accident?	[ "This is because the people who originally wrote down the defining equations of string theory were trying to understand the Strong Nuclear Force. Later when Quantum Chromodynamics was discovered, the string approach was abandoned. Later people started to look at string theory not as a way to describe nuclear forces...	[ "Imagine you grew up flying in a plane. The ground looks like different colors. There's a green area over here, and a brown area over there. When you land for the first time, you're surprised that the green area is actually made up of large trees, and the brown area is made of rocks and shrubs. There are thousands ...
How old did ancient peoples think the world was?	[ "The sequential Long Count calendar of the Classic Maya pegged its beginning (0.0.0.0.0) at the equivalent of August 11, 3114 BC. Since the earliest actual Long Count inscription found is a little under 3000 years after that, this seems a bit arbitrary, even if there probably was some deeper meaning to the decision...	[ "Follow up. Would they be able to figure it out considering the travel times involved in traveling between the hemispheres back then?" ]
How is it possible to cook while camping without being attacked by animals?	[ "Most animals are timid around humans. Even large predators like bears and mountain lions are usually hesitant to approach them. The reason being that any injury could very easily lead to infection or being too injured to catch prey and thus death. This is especially true of the people are in a group. However, bear...	[ "Are you asking about fiction shows or TV as in documentaries? In the case of the documentaries some places it is completely legal to grow. Others, well it’s not hard to hide really if you have the right setup. The hardest part is covering up smell. Some induction fans or blower fans with charcoal filters connected...
Why is it that people are given the grey 'safety blankets' after traumatic events?	[ "Its to help with shock. When in shock the body can struggle to keep warm, so people who may be at risk of shock are given blankets to keep them warm." ]	[ "So, you're a mouse, or badger, or whatever. You're walking through the woods. You are surrounded by brown tree trunks, brown undergrowth, and brown dirt. What color do you want to be when a wolf or eagle looks in your direction? Or, thinking evolutionarily, if you are a beautiful pink badger, what do you think is ...
How exactly does mass bend/warp space-time?	[ "Correct me if I'm wrong but AFAIK there is no accepted theory that rigorously motivates Einstein's GR, and the influence of mass distribution on the spacetime metric is axiomatic in the GR framework. i.e. the bending of spacetime by mass is a fundamental concept and there's no deeper explanation." ]	[ "Air at different densities refracts light differently, like when heat waves coming off the pavement or a grill create pockets of air at different densities. The shockwave has different densities of air ahead of and behind the shockwave, which gives a lensing effect." ]
Why do we get sick from eating the same food over and over again?	[ "My guess is that one food does not contain all the nutritions we need. So if we only eat one type of food, we will lack some stuff that is in another type of food. This makes us weak and / or malnourished, causing us to get sick easier... I'm no biologist / dietist or w/e. Just a simple guy using his common sense...	[ "Computers run on sets of instructions telling it how to run all the parts of the computer and build an interface so you can use those parts. Say you're following a recipe for a cake. Then you finish the cake and someone comes along with a better way to make a cake by adding another ingredient and changing how muc...
If our bodies sweat to keep cool, why then do we want to wipe it off?	[ "No, evolution doesn't work that way. You sweat to cool down. You can't sweat forever, so you ideally want to get to a cooler location. Being uncomfortable and sweaty does two things, it helps you cool down short term and motivates you to get somewhere cooler long term. If you were happy as a clam being sweaty, you...	[ "You rub it on the end of the cues to make the contact surface less slippery, so that more of the force of a stroke is transmitted to the cueball. Same reason gymnasts rub their hands in it when swinging on beams, to maintain grip." ]
Did people in the past drink whisky at all times of the day as is depicted in films set in the past?	[ "Can you specify when you're referring to, roughly?" ]	[ "From what I've read they ate a lot more rough course foods. Chewing things that are hard scrape our teeth for us kind of like it does for other animals. The problem for our modern teeth is we eat a lot of soft refined foods and a lot of sugar. That stuff just sits there and gets stuck which causes tooth decay." ]
What would be the environmental impact if everyone who drank cow milk switched over to vegan milk (coconut, almond, cashew, etc)?	[ "I want to mention that most vegan milks are not nutritionally equivalent to cow's milk. For example: Homo milk has 180 calories, 8 grams of fat, and 9 grams of protein in 1 cup 2% milk has 160 calories, 5 grams of fat, and 9 grams of protein in 1 cup Skim milk has 90 calories, 0 grams of fat, and 9 grams of prote...	[ "The only difference between a full moon and a new moon is the amount of light being reflected from the sun off the moon. Moon cycles are the equivalent of our day and night cycles. A full moon is when the side of the moon we can see is in full \"daylight\" and a new moon is when the side we can see is in full \"ni...
How can astronomers decipher which galaxies are the farthest away in the Hubble deep field?	[ "The Universe is expanding. How do we know that? Since 1929, we've been measuring the redshifts of galaxies - how much redder their light appears to us than it was when it was emitted by the galaxy - and comparing those redshifts to distance. Redshift corresponds to how quickly a galaxy is moving away from us, ...	[ "Scientist would probably start sending radio waves in that direction. That is all that could be done as we have not hope to do anything else." ]
how for example, gun laws are so different from state to state and why they just cant be the same all over the country	[ "> The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people. The 10th Amendment to the US Constitution (part of the Bill of Rights) specifically says that, outside of the powers specifically granted to the Fede...	[ "The cost of a fridge or a car or a loaf of bread doesn't vary much between NYC, San Francisco, and Topeka. But housing varies drastically from market to market. Also, if you're locked into a 30 Year Fixed Rate mortgage, your housing costs don't vary much year to year, but if you're a new buyer or a renter they do....
How did Israel come to have so much influence in the US?	[ "> In addition, when, why and how did criticizing anything concerning a Jewish person or Israel become so easy to label as antisemitism or anti-Zionism, even if the matter is completely unrelated to the person's religion or culture? I ask the followup question because I realized I was afraid of being called an anti...	[ "If you have Netflix there's a very good documentary titled \"the world without US\" It explains your exact question." ]
Is it actually dangerous to expose children to sexuality or is it just our morals? If so, why?	[ "For the majority of human history, children lived in a cave or hut with their parents and sometimes others. They would have been completely exposed to sexuality. It's only when you start to have multi room homes that hiding sexuality from children became possible. even today, in many parts of the world, single roo...	[ "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 m...
Why does everyone freak out about Iran getting a nuclear weapon while North Korea has twenty of them?	[ "Because when North Korea got them, it could threathen Russia, China, South Korea and Japan. Russia and China already have the bomb, and South Korea and Japan have very strong agreements with the US over staying under their nuclear umbrella. If Iran were to get them, then Saudi Arabia would build them, and then the...	[ "One thing to point out is the terrain. Iraq is in the populous parts of the country pretty flat, with a semi good road network across the country making it easy to move people around, and larger cities and towns to organize around. Afghanistan is some of the most inhospitable terrain on earth. With little nation...
Will precession mean that this Veterans Day monument slowly goes out of alignment?	[ "No, because our definition of a year is not exactly the time it takes for the Earth to make one revolution around the sun. A year is the time it takes to make one revolution, minus the small amount to account for axial precession, such that the sun appears at the same place in the sky at the same time of day every...	[ "[Here](_URL_0_) is a quick plot I made using the bodies in your link. There is a linear regression line. I'm not particularly convinced that there is a trend. [Here](_URL_2_) is a more fair linear scale plot of just the \"planets\". And [here](_URL_1_) is the linear section (removing Mercury, Venus and Pluto). ---...
How much harder is my engine running in first gear as opposed to fifth at the same rpms?	[ "At the same RPMs your engine isn't doing anything differently. You just get different work out of the engine depending on the gear." ]	[ "Our brains didn't evolve with cars in mind. They evolved with, like, being hunted by a jaguar (or whatever) in mind. So your brain doesn't know what to do with a car. It thinks hey, we're sitting, our body's not really doing anything physical, there's very little activity or stimulus... this seems like a good time...
why do copper nails kill trees?	[ "They don't, that's mostly an urban myth. It's true that copper salts are poisonous to trees (and people), but the amount of those released by a nail would be far too small to cause meaningful damage to a large, healthy tree. It might work for a very young tree (but you could just cut that down) or one that is ...	[ "The lightning doesn't exactly ask nicely to borrow the electrons. The potential difference is high enough to literally rip the electrons out of the air." ]
do animals know they belong to us	[ "Do animals have a concept of ownership? I know animals can be pretty territorial, but 'ownership' seems like a much more complex idea." ]	[ "How do you know a year has passed without looking at a calendar? I imagine they sense the temperature/climate changes like anything else." ]
Why does nails become white past a certain length?	[ "The keratin of your nails isn’t opaque so it looks white once it grows past your nail bed as there is no blood vessels making it look pink" ]	[ "In the case of bread, it's starch crystallization as /u/steinbergergppro mentioned. In the case of fats (which go rancid), it's oxidation by air." ]
What was the temperature at Planck time and GUT transition?	[ "That formula applies exclusively for the radiation-dominated era. You can see that by reviewing the derivation. So it clearly only applies from the end of inflation up to matter-radiation equivalence. Many people assume the GUT scale is around the end of inflation; in that case the formula should work for GUT and ...	[ "Not a history answer. Did the source say 40 to 70 gr? That could be grains, not grams, and is the equivalent of 2.5 to 4.5 g, which makes a lot more sense." ]
What are the effects of fasting/starvation on cognition?	[ "If you starve long enough you can get something called hypoglycemia. It's a condition where your blood glucose (a sugar) levels drop. It greatly impairs cerebral function and cognitive abilities. Sufferers often appear drunk. It's unlikely with starvation in the absence of existing diabetes that a coma would occur...	[ "Undergraduate psych major here so I'm going to try but you'll definitely be getting better answers here. So you have your two tracks of information coming in. Your attended and unattended information. Essentially what you're paying attention to, and what you're not. So there are multiple models of how memory is p...
Is there a point at which sound cannot get any louder?	[ "For undistorted sound it's about [194dB](_URL_1_) because at that point you're getting a vacuum between the pressure waves. Impulse sounds (shock waves) can be over 300dB for larger volcano eruptions. [Here's a list of high sound levels](_URL_0_)" ]	[ "Quite simply - volume isn't linear! It's measured in dB which is logarithmic." ]
why is there no International netflix library	[ "Netflix has to pay for licenses for each show/movie, for each country it might be viewed in. Some shows might not be acceptable in a certain country, or the holder of the rights wants more for the license than Netflix will pay. I’m sure there are other reasons as well." ]	[ "Because then we would also have to add * Communism/socialism/Marxism * The speed of light * Black holes * How computers work * Monty Hall problem" ]
Why is it the iphone (and other smartphones) requires a separate file type for a ringtone instead of being able to use mp3's already on it?	[ "Because that's how they are set up, ringtones are a separate purchase, so they don't want to lose money buy allowing you to natively create a ringtone from song files on your device. There are of course super simple ways to manually make them into ringtones. It's just that when you pay for the song, you are payi...	[ "They all have slightly different frequencies, which makes it easier to tell the difference. Imagine you're trying to pull one thing out of a box while blindfolded. There are three items in the box. Those three things are all apples, but you're trying to get a Granny Smith. The different frequencies would be like t...
Is there any matter between galaxies?	[ "Sure, though not too much of it. There's an intergalactic medium filled with gas, and dark matter (which accounts for a lot more of the mass in the Universe than gas, stars, etc. do) also pervades that space, though it tends to clump around galaxies and clusters of galaxies. In terms of more interesting objects li...	[ "Not really, for all practical purposes. Nothing that you could sense, if that's what you mean. There's a tiny difference in the gravity exerted on your feet versus the top of your head when you float in the station with your feet pointed toward the Earth, but it's imperceptible - and that difference would be vastl...
Will it be possible to observe the 2024 moonlanding from earth?	[ "No, the angular size of a 10-meter lander on the moon would be about 5 milliarcseconds, which is very very small, about 10 times smaller than the angular resolution of the Hubble space telescope in the visible spectrum. You would need a space telescope 10 times larger than Hubble to observe a moon landing, and eve...	[ "From [wikipedia]( _URL_0_): \"The first landing used slow-scan television incompatible with commercial TV, so it was displayed on a special monitor and a conventional TV camera viewed this monitor, significantly reducing the quality of the picture.\"" ]
why do crunchy, packaged food tends to go soft when left outside the package after a period of time.	[ "they absorb water from the air. They are often packed in nitrogen or another inert, low humidity gas to keep them fresh. When you open them normal air gets in and....floop. They go all soggy." ]	[ "A simple example to augment the sciencey explanation: Basic idea: Materials have a point of no return A simple sheet of printer paper can flop back and forth for eternity with little adverse effect. As soon as something puts a crease in that piece of paper, it is pretty much permanently changed. That crease will...
How does a comment's "karma" affect our perception of that comment?	[ "You may want to browse /r/theoryofreddit , where they do experiments on things like this." ]	[ "OK, so this hasn't been mentioned yet, and this is somewhat important: Reddit just squashes votes. Straight up, number drops precipitously if it gets too high. [From last time this came up:](_URL_0_) > It's because reddit has a vote-squashing algorithm. Have you guys not noticed that every well-voted thread ends ...
Why is the US falling behind the rest of the world in education?	[ "This short clip explains it to a certain degree: _URL_0_!" ]	[ "Your information is wrong. We are 13th on the list. _URL_0_ If you can't take the time to check your facts, please don't post." ]
Why are younger humans/animals tend to be more playful and mischievous than older ones?	[ "Mischeviousness is ignorance of social norms. They'll do things because they haven't learned what other animals or people see as acceptable within the in-group. Once you do learn these things, most people will conform to them to be part of the ingroup. That's why kids do things that are inappropriate. They haven't...	[ "commercialism. if you were happy with your old stuff, you wouldn't need to buy new stuff. all the designers and manufacturers come out with new looking stuff and market the old stuff as ugly and new stuff as pretty in order to make money. our tastes are hugely influenced by others." ]
How would UBI (universal basic income) be good for a capitalistic society?	[ "Given a capitalistic society, it isn't \"good\". If a UBI is necessary, it means capitalism's time for wages system has broken down and labor is no longer valuable." ]	[ "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...
Why (relatively speaking) has the US Constitution remained unchanged for so long?	[ "The interpretation has changed over the years though. This is a major debate in American politics. Whether or not the Constitution should be interpreted only as originally intended or as a \"living document\" whose meaning changes with society. A constitutional law professor could provide a better explanation." ]	[ "Each flu has it's own \"strain\". A type. A shape and identity. Once it gets into your body and starts reproducing, it doesn't matter much if you get a few additional cells of influenza in your body, it's a drop in the ocean. And once your immune system identifies and develops a resistance to it (based on it's s...
What happens to that .1 percent of bacteria not killed by antibacterial hand soap? What are they? Could they be dangerous?	[ "The 99.99 percent of the bacteria killed by the hand soap are not likely to be dangerous in the first place. That is probably the most important part of the topic. Further, regular soap washes away bacteria pretty darn well. Even further, some bacteria is really good for us - our understanding of this is incomplet...	[ "A phone's battery percentage is an estimate of how much power it has left based on the power it is providing. Using an app that drains a lot of battery and checking the battery while it is still running will cause the ping reaction of checking battery to take a longer time to reach the sensor, resulting in a lower...
Why isn't there a formula for the roots of a quintic polynomial?	[ "This is a result of the [Abel-Ruffini theorem](_URL_3_), the proof of which is rather complicated. It relies on [Galois theory](_URL_1_), and the fact that the [group S_5](_URL_2_) doesn't have a particular property called \"[solvability](_URL_0_)\" (nor does S_n for any n > 4)." ]	[ "Well that depends how the venoms work. Some may work by simply working opposite of the poison they're meant to counter, some may bind the venom, lessening its effect. Example, in atropine poisoning, one would use pilocarpine. Atropine is a paradympatholytic agent, pilocarpine is a parasympathomimetic. What that me...
How the Nazi party got total control of the government of Germany so quickly after Hitler's election	[ "The best way to understand it is through the account of a teacher who performed an experiment at his school, called 'The Third Wave'. It is a long read but it is worth it and gives you a much better insight than a few succinct paragraphs on ELI5 would. _URL_0_" ]	[ "In a nutshell, the company used creative accounting measures to use the chance of future profitability to provide cash immediately. The best example is the building of various power plants, which would take years of construction. However, they could immediately offset the cost by booking future profits, thereby se...
Who are these warlords in the late Qing period?	[ "Just posting a followup question if thats okay. Did any of these warlords and their factions survive into the republican era?" ]	[ "I'm trying to better understand the historiographical genealogy of John Dower's War Without Mercy. Was a racial understanding of the Pacific War's brutality unprecedented? What are the other main scholarly explanations for the fighting's horrific character?" ]
How (if at all) does the external environment affect what "baby sounds" a child will make before their first words?	[ "Babies come out able to make any sounds, of course, but they start to figure out which sounds are important for the speech of their particular language pretty quickly. They start to respond to the sounds of language differently within a few weeks. When they start to babble they makes all kinds of sounds. When they...	[ "Imagine you wanted to send a digital file to a friend of yours, but all you have is a telephone and the binary data contents of the file. You tell your friend \"when I say beep you write down 1, when I say boop, you write down 0\", and then you read the contents of the file to him over the phone \"beep beep boop ...
Street drugs and their effect on people (UK language if possible)	[ "Uk Language? Pills will get you proper munted. Like out yer bonce. It'll make you think chubbers are buff and pull shapes all night. Draw makes you want to cotch. Then you get bare munch and need to smash a mint Aero and Potnoodle, maybe a maccie d's. Chang will make you Brap." ]	[ "It makes you feel good, so you do it more and more times, but your brain adjusts that sensation and so you need more and more of the thing to fell the same" ]
When I shake a container filled with liquid (0 headspace), is that any different from when I shake a container slightly less full?	[ "Yes. Although I cannot explain why, but I can show you this (2 part) video which (accidentally) looks into a container of liquid full and slightly less full _URL_0_ _URL_1_" ]	[ "Your whole high school is in the gym for an assembly. The presentation comes to an end and everyone needs to leave all at once. If you never open the doors, people will never leave. If you open one door, how long will it take for everyone to leave? If you open all the doors, how long will it take for everyone t...
How do Diamonds form?	[ "The carbon is not being crushed and heated in the presence of O2 gas. Does this help?" ]	[ "The actual disc of any star (excluding the sun of course) as seen from earth is so tiny as to be nearly invisible. The apparent size of a star is just caused by diffraction through the atmosphere (which also causes twinkling). So all stars are points of equal size that get get equally distorted." ]
How does the "Hola - Better Internet" Extension for Firefox and Chrome work?	[ "Hola will put itself between your computer and your destination. So instead of computer - Internet - destination (and the way back) The following will happen: Computer - Internet - hola server - Internet - destination (same on the way back) Your destination believes your request comes from US (or somewhere el...	[ "Country specific ones follow the laws of that country. You can search for Tibet freedom on _URL_0_. but not _URL_1_ or Google.can Google was given a choice by Chinese gov. Either you make the search engine follow our rules, or you don't do business in China at all and China blocks _URL_2_ entirely" ]
What value was French Algeria to France?	[ "Anyone interested in the end game of French rule in Algeria can watch \"The Battle of Algiers\" which is mostly historically accurate. An excellent view, not only for the political history buffs." ]	[ "Why did allied power just create a separate state for Christian area of Lebanon ? Would that have averted the civil war" ]
What happens to the Treaty of Trianon in 2020?	[ "We're not in the business of predicting the future, but I guess you're asking if an 'expiry date' was agreed for the treaty when it was signed in 1920?" ]	[ "Hi, this is just a reminder to posters to abide by our [subreddit rules](_URL_0_) and remember that unless you're posting an in-depth reply about the history of the issue, your post will be deleted. Pay particular attention to the rules about soapboxing and the 20-year-rule. We don't need discussion of present-d...
What exactly does a producer do on a film, tv show or cartoon?	[ "Source: I work as a technician in a student theatre, but most of it will scale up. They tend to be the top level of the production, it will be there responsibility to ensure that everything (from the licences, scripts, rehearsals, crew, cast, finances etc) is being planned and executed effectively. The larger the ...	[ "They have a profit margin built into their items, and they are willing to decrease the profit margin in order to keep customers. They'd rather make less money on each sale, than annoy customers and stop selling anything at all. Sometimes stores also have loss leaders. For example, supermarkets will often have very...
Could the end results of round-robin tournaments be reliably predicted based on a smaller amount of randomized matches?	[ "Yes, you can do sparse pairwise comparisons and still get decent ratings. This has been done for decades in chess, for example, with the Elo system. Glicko and Glicko-2 are highly regarded generalizations of Elo. Most online games today involve some sort of server-side rating system, although these tend to be more...	[ "Using statistics. A representative sample of a country's population either get asked to keep a record of what they watch or listen to or have devices in their TVs or radios that do this. This information is gathered and the figures are scaled up to the whole country. EDIT: grammar" ]
Why is it that we don't remember falling asleep or the short amount of time leading up to us falling asleep?	[ "One aspect is that the information isn't that important and you're not receiving much information into the brain, so what is there to remember? What colour was the 3rd car you saw yesterday? You have no idea because your brain doesn't store information unless it thinks it's important. It's also important to reali...	[ "There are a few factors at work here : Moſt chairs are deſigned to ſit at about knee height ; they generally ſupport your back, and more importantly, your butt and legs. Toilets are uſually lower, and they are made with a large hole in the middle, into which you ſink a little. This lower height, lack of ſupport,...
Stephen Hawking says there was a limited agreement - that the Nazis agreed not to bomb Cambridge and Oxford if the Allies would refrain from bombing two important German university cities, one of them presumably Heidelberg. Is there any evidence for this?	[ "Nonsense I'm afraid. Cambridge was certainly bombed _URL_2_ _URL_0_ Oxford was, perhaps difficult for the German bombers to identify? It was certainly a legitimate target as the Morris motor works were there at Cowley, building military vehicles, amongst others. Other cities without particular military importance ...	[ "Karachi (largest city in Pakistan) is currently experiencing some large problems; both in crime, and politically. This is in part due to [Altaf Hussain](_URL_0_) who is the founder and leader of the [Muttahida Quami Movement](_URL_1_) - a political party in pakistan based in the city of Karachi. The problems surro...
Do languages that use other characters (cyrillic, arabic, russian, chinese, japanese, etc) still have a concept of ordering like the latin alphabet? If I'm sorting my Japanese contacts by last name, what order do they go in?	[ "Russian/cyrillic has an alphabet; it's still a \"western\" language in that you are spelling words, not so much using symbols. Edit: Why downvote? I promise, Cyrillic languages have an alphabet. Written cyrillic is rooted in Greek. They also have an alphabet." ]	[ "Since Google can see what links you click on from their page, their system can notice that searching \"Asa Akira\" (nice choice BTW) tends to lead to pornographic sites. Using this information, they'll decide that the term indicates a desire for pornography and they won't put it in auto-complete. It's fine if you ...
Why is it so expensive to extract gold from ore?	[ "To be a profitable gold ore it's concentration has to be at least 1.5 g/t. Lets say you have a gold ore with 5 g/t. To get 1 kg of gold (~45'000 USD) you need to mine 200t of gold ore (rocks get rid of to get to the ore not included!). Then you have to extract the ore from the rock. This is accomplished by grindin...	[ "Energy consumption, pure and simple. RO membranes, hydrolysis, evaporation, etc., all take energy. A lot of it." ]
Why everyone in the US isn't required to vote	[ "Freedom means freedom from participation, if you so please. You don't HAVE to assemble or speak your mind, but you can if you want to." ]	[ "This CGP Grey video does a really good job of explaining it all. _URL_3_" ]
in HBO rome none of the streets in Rome have names or numbers, people just identify places by saying things like "my house is behind the street of the cloth dyers". were ancient cities really that disorganised?	[ "Hey! I don't want to discourage other answers, especially since this is only part of the answer to this question, but [this answer](_URL_0_) on the question of how to find the place you were searching for in Rome itself might be of interest. Also see /u/cerapus answer in the same thread, which makes the very perti...	[ "Most neighborhoods built after the 1950s, ie subdivisions in the suburbs, are built all at once. Meaning they will all be built within a year of each other and use 1-5 building plans. Homes built in cities or on privately owned lots outside the city limits that are not a part of a subdivision are built as the owne...
What's the difference between gasoline and diesel? Why is the other used over the other?	[ "Diesel is also known as fuel oil. It’s more of a light oil than gasoline. Diesel engines rely on compression rather than ignition to burn. They don’t have spark plugs like regular gasoline engines. In larger engines diesel is better because you can get better mpg than gasoline engines. The larger engines have mor...	[ "Ask Reddit is for personal opinions, stories, and the like. Essentially subjective answers to questions without hard answers. Something like \"whats your favorite food\" is a good post there ELI5 is for getting a simplified answer or explanation to a question that you don't understand. A good thread here would som...
Do aromatic molecules have a defined smell, or do different animals smell things differently?	[ "Smell cannot be objective. It is a sense that only has a definition with regards to human beings. An object does not inherently have a smell (or color for that matter), it releases molecules (or certain wavelengths of light in case of color) which are characteristic of the object. How those molecules (photons) ind...	[ "Probably the most used method is [x-ray crystallography](_URL_0_). You have to be able to make a crystal out of something, then you shoot x-rays at it and analyze the diffraction pattern that comes out, using incredibly complex mathematics. There's a problem with this method though, in that it's hard to get allotr...
What is the diffrence between a regular and a light cigarette?	[ "A lot of it has to do with making the filter more porous so that the ratio of air to smoke is higher in \"light\" cigarettes. \"Light\" cigarettes are no longer sold in America." ]	[ "Because plastic doesn't have melanin or vitamin D. Also, it does happen with your hair. If you have brown hair, it can appear to look lighter because of sun exposure." ]
What in the body warms blood?	[ "The product of cellular respiration (how our cells convert sugar into usable energy or ATP) is C02 water and heat. To perform even the most basic functions of the cells, our bodies are constantly creating C02 water and heat. It's not that there is necessarily a function that warms the blood, but it is a cumulative...	[ "Heat is generated by the combustion engine transferred into the coolant through a heat exchanger (radiator) then pumped to another heat exchanger ( heater core) where it is transferred to the cabin air by a blower motor" ]
how do we measure a day on a planet like Jupiter if the entire planet is essentially just a giant cloud?	[ "Gas giants can have differential rotation. Different latitudes on Jupiter spin at different rates. The polar regions on Jupiter take ~5 minutes longer to make a full rotation. Also the rotation of Jupiters magnetosphere is also used as a measure of 1 day on Jupiter." ]	[ "Randall Munroe, the artist behind _URL_0_, completed an epic and award-winning project called 'Time'. At one point in the story, he [depicted a night scene](_URL_1_). Well, his audience was geeks, so within a hour or so we had determined, by the proper motion of the stars, the location of the planets in the starfi...
Are Gravitational and Inertial Mass Always Perfectly Proportional?	[ "1) As far as we know and the general relativity is concerned, yes, inertial mass and gravitational mass are always the same. This is, in fact, one of the postulates of general relativity. If it was found that inertial and gravitational mass were not the same, general relativity would have to be augmented somehow. ...	[ "I think this is probably one of the (many) problems that currently makes space elevators impractical. My thought is to start by launching a rocket into geosync orbit carrying a spool of small cable and then using a projectile of some sort to launch the end of the cable back to Earth. Once it's back on Earth, you c...
When wearing a headset or earphones, why does it sound like the music is “inside” of ones head?	[ "How loud a noise is in one ear, relative to the other ear, allows the brain to estimate where the source of the sound is coming from. When both sounds in each ear are in sync and being received at the same volume, your brain figures that the source of this noise must be located between your two ears; the middle (o...	[ "The human brain is great at recognizing patterns and is very used to making predictions about the environment. For example, due your experience, when you're walking in the street your brain tells you \"people are walking in a certain direction and they're going to keep doing so\". When you experience something new...
Why are a lot of videos on YouTube not available on mobile?	[ "Because whoever made the video can't get the money from ads so they choose to make it unavailable on mobile." ]	[ "Costs money to build and maintain the facilities, some countries don't feel like taking on the burden of that cost." ]
Amanda knox: What were the reasons she was presumed guilty for in the first place?	[ "It's a pretty messed up situation. No one was convicted before she was, but someone else confessed to the crime while they were investigating Amanda Knox. However, the Italian prosecution, determined to make a splash by convicting an American girl of a heinous crime, cooked up a theory that she had worked in con...	[ "It's similar to pandora, though I don't know what kind of arrangements they have in terms of paying licensing fees. They allow for a more specific selection of music, and allow you to create playlists as if their entire library was your own. Think of it as a cloud-based napster. They have a desktop app as well as ...
where does money come from	[ "There are two main ways - 1. The central banks of the countries print more money 2. There is a money multiplier effect - Assume that you deposit Rs 1000 with your local bank. Your local bank need not keep Rs 1000 in your account always. The percentage amount that it has to keep is determined by a reserve requireme...	[ "Yes Each cell in your body has 2 copies of 23 chromosomes, 23 from mom and 23 from dad. Sperm has a single set of 23 chromosomes, each one randomly picked from mom or dad. In addition, chromosome from mom and dad also exhange information. So even if you get a chromosom from your mom, it might have some Dad's gene...
How early was the first of what we would consider a "military campaign?"	[ "Well we have records of of Akkadian, Assyrian, Sumerian and other Mesopotamian conquests dating back to around 3000 BCE. These records come in the form of art carved upon decorative pieces depicting conquests of cities. Though I believe the first battles we have written texts for are the battles of [Meggido](_URL_...	[ "You're thinking of Philip II, Philip I was the third Argead king of Macedon and reigned back in the Archaic Period. There's a number of previous threads on this subject. [Here's one I wrote myself, though there are any others](_URL_0_), although there are many others. But the short version is that Sparta...really ...
Is there a website shows changes in countries borders year by year ?	[ "I think you might be looking for this: _URL_0_" ]	[ "Try _URL_1_. They have some short tutorials and online algorithms you can use to examine photos. I've used the site on occasion to check if some Reddit images are faked. Very informative site. Also, check out captain disillusion on _URL_0_. He debunks videos which have been altered and explains how he determines i...
How does our way of thinking change as we grow up?	[ "Arguably the biggest distinction between children and adults, cognitively, is the ability to think using abstract ideas. Many \"adult\" problems are abstract, but children do not start gaining the ability to think abstractly until adolescence, so about 12 years and older. [Jean Piaget calls this new stage of devel...	[ "Becaus for most if them their frontal lobes aren’t developed yet and are very easily molded by repetition and hype. Adults have the ability and experience to see the BS in ads." ]
Is it possible to harness the energy from deep sea vents?	[ "Not only is it possible, [it has been proposed](_URL_0_) as a power source for deep-sea instruments. Edit: fixed link" ]	[ "There's an experimental plant called [ITER](_URL_0_), still under construction. The trouble with fusion is that you're basically putting the sun in a bottle, but we're still figuring out how to make the bottle." ]
What beliefs/qualities made Prince Henry of Prussia the ideal "Enlightened Monarch" in the eyes of Voltaire and American Founding fathers wishing to make him King of the U.S.?	[ "What on earth is your source for that conjecture? My graduate school advisor was an early Americanist and I've never heard anything similar. Also, Voltaire died in 1778, three years before the American victory at Yorktown. How would he have proposed a monarch for a nascent country that didn't yet exist? EDIT: Ap...	[ "The Bohr model can't really 'prove' Planck's black-body law. It assumes (ad-hoc) that angular momentum is quantized, without any rationale, really. (Except the one given later by de Broglie in terms of de Broglie-wavelengths) The Bohr model doesn't obey the uncertainty principle, the Schrödinger equation does. Not...
What/Who determines what becomes a hit song on the radio?	[ "[Payola](_URL_0_) Managements groups (artist representation, labels, PR & Marketing, etc) determine which songs should be strategically promoted to best influence the consumption of an album, and funnel payments into radio stations (through third parties) to influence what those stations play." ]	[ "TV Stations actually don't really \"pick\" commercials. Stations have advertising slots open for anyone who is willing to pay to advertise there. Now for the advertiser that slot must be worth the money they are paying to sell their product. That's why is you were to watch Nick, Disney or Cartoonnetwork you see a ...
Why does coughing sometimes make you vomit	[ "Coughing and gagging have the same goal in mind, which is to clear something unwanted from the airway or esophagus, respectively. These two \"tubes\" only separate from each other down a ways in your throat, where higher up they're a single tube. Even after they separate, they're close together for a bit. As a res...	[ "What do you mean by “swallow them wrong”? Like, choke on it?" ]
Saddam Hussein hero or villain?	[ "One problem in general with this sort of analysis is that it compares the actual record of the dictator with a hypothetical 'no development'. We simply cannot know how a freer Iraq might have developed. Whatever he achieved, Saddam brought his country into two disastrous wars with Iran and Kuwait and committed mas...	[ "Hi, I've approved the post, but just a note to you and potential respondents: this subreddit has a 20-year rule against discussing current events, so any answers will have to cut off at 1997. If you're looking for answers that can include 1998-2012, do consider x-posting elsewhere, eg. a foreign affairs sub like /...
Can bacteria feel pain?	[ "Not in any sense of the term that would make sense from a human perspective, for sure: by definition, single-celled organisms don't have nerve cells, and what we call \"pain\" is entirely a nervous-system response to various stimuli." ]	[ "Plants and single-cell organisms don't have brains either, and they move, reproduce, eat, etc. Jellyfish do have nerves, and they're distributed all over the jellyfish body, so you might call that a decentralized brain... What makes you think life needs a brain?" ]
Does the reported scientific consensus about the safety of consumable GMOs include an evaluation of studies about their effects on human gut microbiomes and epigenetic codes?	[ "First, it isn't really correct to say there's a scientific consensus about the safety of consumable GMO's. That's like saying there's a scientific consensus about the safety of eating non modified plants. There's some natural plants that are poisonous. You could conceivably make some GMO that are poisonous. The wa...	[ "I bought a book at the SAAs on Baja California archaeology for the sole reason that I know nothing about the work from that area. It should be an interesting read. I also preordered an English translation of the Relación de Michoacán which should be fun. And I bought Rethinking Anthropological Perspectives on Migr...
Did Racism Cause the Enslavement of Africans?	[ "For the most part your statement \"enslavement caused racism\" is correct For most of history slavery was a relationship of power, it had very little or nothing to do with race, Greeks owned enslaved Greeks, Romans owned slaves with Italian blood and most importantly African tribes enslaved one another. With the c...	[ "This submission has been removed because it is [soapboxing](_URL_1_.), [promoting a political agenda, or moralizing](_URL_0_). We don't allow content that does these things because they are detrimental to unbiased and academic discussion of history." ]
How massages relieve?	[ "Imagine you’re a wrinkled shirt. Masseuse straightens you out so you’re nice and unwrinkled. But some people are so use to be wrinkled, they don’t know how it feels to be unwrinkled. That’s my best ELI5. I tried." ]	[ "Doc here. I just want to add that all the people talking about Takotsubo Cardiomyopathy as an explanation for why your chest hurts when you are sad or anxious seem to have misapplied some wikipedia knowledge. That disease is in no way related to the sensation of pressure in your chest you get with emotion. It is a...
How are the voices and recordings on Voyager 1 coded, and how will the alien race know how to use them.	[ "[It's stored on a record!](_URL_0_) A golden one at that. It's pretty straightforward technology and it comes with some diagrammatic instructions on it." ]	[ "It's tough to do that. What is required is a reference. For hiroglyphics in Egypt for example that reference was the Rosetta stone. On it the same text was written in hiroglyphics, greek and babylonian (I guess...) So they could work from there. If there is no reference whatsoever and it's not a 'root language' fr...
So beer has been around since basically the beginning of agriculture, and I know it was brewed extensively in medieval Europe in monasteries, but how different was this beer from what we have now taste wise? What was considered a "good" beer?	[ "One of the ultimate historical alcohol resources out there is [A Sip Through Time](_URL_0_), which has recipes from the ancient Egyptians up until the prohibition era - including some that we now know to actually be harmful. Tossing a medieval monk a Budweiser would be a sight to see! The monk would recognize it ...	[ "The placebo effect, and confirmation bias. Imagine you have an item you feel is lucky that you bring to a baseball game. You generally feel \"hey, if I have this, I'll hit better.\" Subconsciously, you will apply yourself more, as well, because of the added confidence. Usually. Alcohols can affect people similarly...
How does Hypnosis work?	[ "Basically, you find a really dumb person or someone who really wants attention, and you convince them to act for you when you do something. See, the desire for attention manipulates the mind with a chemical triggering of desire stemming from low self esteem. Thus, when the \"hypnosis\" occurs, the subject is \"hyp...	[ "By what it will buy. That's pretty much it. What it will buy is influenced by outside psychological factors: do gas suppliers think a shortage is coming up? Less gas for the same money. Was there a major crop failure someplace? Fewer groceries for the same money. Did the stock market drop last week? Prices in gen...
Why does a glass leave a ring of liquid on a table when no liquid has spilled?	[ "I stole this from google. “When water vapor in the air comes into contact with something cool, such as the outside of a cold glass of lemonade, its molecules slow down and get closer together. When that happens, the gaseous water vapor turns back into liquid water droplets. That's condensation!”" ]	[ "Do you have a fly screen over the window? If so what you are observing is a [Moiré pattern](_URL_0_) being projected onto the window. Essentially the light is passing through the screen and the light waves get split up and then interact with each other causing spots of superposition where some regions are darker a...
In bars and restaurants, TVs that are playing the same thing, how are some timed perfectly while others playing the same thing could be as much as like 7 seconds delayed.	[ "Digital TVs have to decode a digital signal and then render it for the screen/speakers. Some TVs process faster than others." ]	[ "I don't so much think of it as an evolutionary thing. There's really no benefit to being confused. It comes down to computing power. Your brain just takes a minute to recall old information/piece together new information to develop an idea of where you are and how you got there. I'm currently in flight school and...
Why do some countries want to keep their currency value low?	[ "I am learning about this right now in my international finance class. By a country putting a peg on their currency (usually to the USD) it makes their economy \"stable\" in relation to the rest of the world, allowing for other countries to invest knowing that their currency will not have huge fluctuations. This is...	[ "Think of a rare baseball card. If there's only 10 of them in existence, then everyone would want them and they would be willing to trade hundreds of chocolate bars for it. Now think if they printed 990 more of that rare baseball card. Now everyone has one, and no one is willing to trade a chocolate bar for it." ]
Rocket Science - How Exactly Does Thrust Work?	[ "The easiest way of conceptualizing how a rocket engine works is by imagining you are wearing ice skates and standing on ice, while holding a few bricks. If you throw a brick away from you really hard, you will start moving backwards. Now imagine you have billions of bricks, and you're shooting them out with, well,...	[ "This video from Sagan will help. I couldn't explain it in a better way. _URL_0_" ]
What would happen if the speed of light suddenly increased by 1%?	[ "It would be totally indistinguishable from the universe we live in. See [here](_URL_0_)" ]	[ "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 a...
How is the earths weight calculated?	[ "You can’t really tell the “weight” of the earth. Remember, weight is dependent on the gravity of the environment as well as it’s mass (weight=mass*acceleration of gravity, where the acceleration of gravity is different for each planet) so since the earth is sitting in space, it doesn’t technically weigh anything. ...	[ "When a lot of stuff floats around it tends to group up... as those groups form they get more and more attracted to eachother. The more stuff there is the more gets attracted (gravety). Eventually there is so much stuff that the middle gets very hot! Everything there turns into this super dense ball. it keeps pulli...
What makes a person have a chronically messy house (from a psychologist's perspective)?	[ "You are confused about what OCD is. A person with OCD could definitely have a messy house. As a matter of fact, some times having a messy house is a symptom of a person's OCD." ]	[ "When you add a file to your computer, it gets put in the first available space - even if that space isn't big enough to fit the entire file in. If the space isn't big enough, the file gets SPLIT into several pieces and put in different places. Over time, constantly adding and deleting things means that all the stu...
How do farmers produce millions of batches of coffee/wine that taste the exact same every year?	[ "It’s not so much about the uniformity of the beans/grapes, as it is about the treatment after harvesting. That’s where the flavor profile can change most." ]	[ "Many high end restaurants (or restaurant suppliers) get first pick. Particularly when it comes to meats and other things that spoil quickly. How many people at your supermarket are willing to pay top dollar for prime or whagu steak? Vs people going to a steak house." ]
As the theory states, the Higgs boson gives mass to other particles, but what gives mass to the Higgs boson itself?	[ "The Higgs mass is a \"builtin\" mass in that it comes from the potential for the Higgs field. Near the minimum, there is a quadratic part to the potential which gives the Higgs a mass (there is also a quartic part, which gives the Higgs a self-interaction). This is to be contrasted from how the other particles get...	[ "Talking about what is happening \"right now\" inside a black hole makes no sense. Time stops, as far as we're concerned, at event horizon, nothing ever passes that point. If you were to go through the event horizon, it would be a different story. Energy won't come from nothing. Black hole increases in size as it e...
What exactly is cold fusion and why is it considered impossible?	[ "Well, regular fusion involves heating hydrogen to such a high temperature that the protons start fusing into helium. This is what happens in the sun. There are some experiments on Earth trying to achieve this, but they can't do it in an energy efficient manner. In the next decade one should open in France that doe...	[ "Many years ago going to the moon seemed Imposible, Negativity ain't gonna bring ya nowhere bruh" ]
How, if at all, are traffic lights coordinated within a proximal geographic area?	[ "Sometimes traffic lights may be interconnected with other traffic lights and communicate with a control that helps ease traffic. Other times they operate by themselves some even use gears kind of like a clock to predict when to change. Most modern lights are digital though. _URL_2_ Edit: I found this information f...	[ "Hey! I don't want to discourage other answers, especially since this is only part of the answer to this question, but [this answer](_URL_0_) on the question of how to find the place you were searching for in Rome itself might be of interest. Also see /u/cerapus answer in the same thread, which makes the very perti...
Before the invention of the phonograph, did people realize that they don't hear their own voice the same way as everyone else?	[ "I realized this as a child when I had a head cold. Also I would imagine that there were some instances where the director of, say, an opera told their directee that they were not sounding like they thought they were sounding." ]	[ "This is a huge problem for all historians, and especially when trying to decipher human history from before the written word, ie pre-history. And that of course even makes the assumption that written history is by default more credible, which is far from true (and much written history is just adaptations of oral h...
how to TV shows like Breaking Bad, The Wire, Walking Dead etc... manage to maintain such a consistent tone/feel despite using different directors and writers?	[ "The show-runner for Dexter must have been asleep at the wheel." ]	[ "Lots of chemical science and a base batch of fermented liquid to flavor. There isn't a lot of nuance in mass marketed booze, and practically every part of a flavor can be measured and replicated. The varietals are all put together the same way with tried and tested yeasts for exact Temps and times. They've removed...
What was the reaction of the Western Allies to the German defeat at Stalingrad?	[ "American newspapers were surprisingly informative and highly supportive of the Russians, headlining daily while the battle went on. I have a collection from this period and nearly every day there was report of the stubborn resistance or high casualty count inflicted. They were our allies, they were doing the heavy...	[ "Ah yes I'm familiar with this story. On Culin's own admission (note: speaking of inaccuracies, the 102nd Cavalry Group was not a unit of the 2nd Armored Division, but rather a corps level formation in the 1st Army), he took the idea, stated awkwardly and generally from a self-described dimwitted comrade, and ran...
To what extent do female and male brains differ biologically, not taking into account cultural conditioning?	[ "It should be noted though, that we have seen big differences between men and women when it comes to things like autism or depression that can't be explained simply by conditioning. But that indicates mostly hormonal involvement. Behaviour differences have a lot to do with minor physiological traits people not alwa...	[ "_URL_2_ columnist William Saletan waded into this issue several years ago with similar questions to yours. Here's an article posted AFTER his initial article and several followups, all of which can be reached via links within the article. It's an interesting journey with commentary from psychologists, statistician...
Why do humans like to kiss each other?	[ "It releases hormones that feel good, such as oxytocin. Why does it release hormones like that? Because a kiss is a good way to determine the health and immunological compatibility of a mate. If it is good, hormone are released and you want to do it again, because you get a good response from the partner. This enc...	[ "Hi OP, this is a cultural question, so it would greatly assist anyone considering answering if you could specify which culture you're asking about. For example, the name of a cultural group / country / geographic region, plus a rough time period. Otherwise, this question is simply too broad, as it encompasses almo...
My friend has been telling me the Civil War started because northern whites were getting sick of former slaves migrating north, so they became militarized. Is there any truth to this	[ "You can find some excellent answers about this [in the wiki](_URL_0_). I especially like [this answer](_URL_1_) from /u/Georgy_K_Zhukov TL;DR: Your friend is almost as wrong as wrong can be." ]	[ "Traditional cheddar is yellow due to being made from the milk that is high in fat content (giving it the yellow color). White cheddars will be made from lower fat content milks. Since the lower fat content milk is cheaper (as they are selling off the cream or making butter with the part they remove) some cheddar p...
Where did languages such as Mandarin, Korean, Cantonese, and Japanese originate?	[ "> Most European languages stem from Latin That's not quite right. Only the Romance languages (Spanish, French, Italian, etc.) descend from Latin. However, the vast majority of European languages are part of the Indo-European language family. > Mandarin, Japanese, Korean All three of them belong to different lan...	[ "There is a theory that the closure of the Panama Isthmus is what [began the Ice Ages](_URL_0_). > A growing body of evidence suggests that the formation of the Isthmus of Panama partitioned the Atlantic and Pacific Oceans and fundamentally changed global ocean circulation. The closing of the Central American Seaw...

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