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1acmjh | how do conservatives who want less government ally with religious people who want the government to legislate morality? | I don't ask in the interests of trolling, as I seriously don't understand the conflicting ideas. If anyone could explain to me why they can hold both beliefs I'd be much obliged. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1acmjh/eli5_how_do_conservatives_who_want_less/ | {
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"I often wonder this myself. People with the Bible in one hand and Atlas Shrugged in the other and don't realize they oppose each other. ",
"The simple answer would be: because people who reject centralized authority on principle tend to prefer small communities, especially the concept of the family. A social conservative would say that a well-structured family could care for its children better than a million well-meaning social programs. And a lot of these people feel that the concept of the family needs to be protected, so children don't end up in \"government-approved social units\" that don't provide the kind of support that the traditional nuclear family does.",
"The way I understand it, in the wake of Watergate the republicans had a very severe PR problem and needed some new alliances. Before this point there were movements to try to ally the social conservatives with the GOP with mixed results. Along came Reagan and that was where the movement got real traction. The social conservatives had a real rally cry fighting against abortion and the bottom line is that the alliance proved to be a real big win for the GOP. That is very short, incomplete version of the history behind it.\n\nBeyond that it does not make a whole lot of sense to me either. For one, post Bush 2 I don't buy into the GOP being a fiscally conservative party in favor of small government. They are for low taxes, but they had no problem exploding the size of government when they had house, senate, and the White House from 2000-2006. The problem is that the social conservatives are the ones that bring the votes and not the small government crowd. If libertarians were the more dominant group I think we would see a vastly different GOP. The one we have gives lip service to small government and has pushed a pretty effective PR campaign to equate low taxes to small government. The end result is the exploding debt problem we have now. Democrats share the blame since they have no problem with big government and have not proposed revenue sources that can get past the GOP. Income taxes are not the only revenue source folks and that is the one the GOP hates.\n\nTo summarize, the GOP is just as big a tent as the democrats. They have just been better at herding their cats than the democrats.",
"They can't since they're utterly contradictory.\n\nThe social conservatives are kind of a booby prize in American politics. They used to be all Democrats, then post-desegregation, they moved to the Republican party.\n\nThe unfortunate consequence of this is that the \"party of fiscal responsibility\" isn't, and you end up with two parties who both want bigger government, but different kinds.\n\nThe one part of small government conservativism that remains is the hostility toward taxes...It's not fiscally responsible (fiscal conservatives would put higher taxes above higher deficits), but it's bearing some weird fruit in the cross-the-board budget cutting measures.\n",
"Most human beings base their actions and beliefs on instinct and emotion. Logical consistency is, at best, secondary. Often it's an even lower priority.\n\nThe other answers explain why mainstream conservatism in the US currently has conflicting core ideals, but the general principal is applicable to everyone in every area of human interest.",
"It has to do with the duality of the american political system. The left has its ideological background in the progressive and socialist movements, which tended to be, at the very least, ambivalent about religion. \n\nThe background of modern conservatives, on the other hand, tended to reactionaries who favored tradition. Tradition includes religion."
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4yu6p7 | baltics, eastern europe or northern europe, and why? | Title says it all. I always assumed it to be Eastern Europe, but I've recently found that they are actually considered "Northern Europe". What makes it Northern? Why then isn't Poland Northern Europe or Serbia? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4yu6p7/eli5baltics_eastern_europe_or_northern_europe_and/ | {
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"The definitions of the regions of Europe are arbitrary. There is no single official, \"correct\" way to define them.\n\nSo perhaps some people consider them Northern Europe rather than Eastern because they feel they have more in common with the other countries in Northern Europe. Or it could be because they are physically as far north as some of the other countries.\n\nIt does seem like it's more common to categorise them as Northern Europe, but sometimes they are considered Eastern Europe."
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lrt68 | what determines the color of poop? | No I'm not joking. And remember to keep it elementary. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/lrt68/eli5_what_determines_the_color_of_poop/ | {
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"Bilirubin is a compound released when a red blood cell is \"broken down\". It gives poop the brown color.",
"TLDR: Sterocobilin: _URL_0_\n\nThe bile Pigment Sterocobilin (end product of Heme metabolism) is responsible for the color. Heme in Hemoglobin contained in Red blood cells is transported to the liver where it is converted to Bilirubin and secreted with bile via the bile duct. Bile is secreted into the Small intestine at the Ampulla of Vater, and is used to help increase the surface area of fats to speed digestion. Bile is processed into Sterocobilin by bacteria and secreted as feces.",
"dead red blood cells. to put it simply, they \"rust\", which is why it's brown.",
"when I was a kid I once drank a whole lot of root beer, and then my poop was green.",
"Here you go: _URL_0_",
"What you eat can change the color. My friends once swallowed a soda tab and pooped gray.",
"Bilirubin is a compound released when a red blood cell is \"broken down\". It gives poop the brown color.",
"TLDR: Sterocobilin: _URL_0_\n\nThe bile Pigment Sterocobilin (end product of Heme metabolism) is responsible for the color. Heme in Hemoglobin contained in Red blood cells is transported to the liver where it is converted to Bilirubin and secreted with bile via the bile duct. Bile is secreted into the Small intestine at the Ampulla of Vater, and is used to help increase the surface area of fats to speed digestion. Bile is processed into Sterocobilin by bacteria and secreted as feces.",
"dead red blood cells. to put it simply, they \"rust\", which is why it's brown.",
"when I was a kid I once drank a whole lot of root beer, and then my poop was green.",
"Here you go: _URL_0_",
"What you eat can change the color. My friends once swallowed a soda tab and pooped gray."
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cn4pqs | how do bruises heal themselves? | When you get a bruise, the black and blue spot you observe is a result of burst blood vessels beneath the skin. Where does the blood go as the bruise heals? What happens to it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cn4pqs/eli5_how_do_bruises_heal_themselves/ | {
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"Bruises are caused primarily by capillaries being crushed and blood seeping into the skin. A bruise fading is just the blood breaking down or being reabsorbed by the body. \nAt least I think I'm right on that.",
"To know why it heals you have to know that a bruise is just a bunch of broken blood vessels in the area of impact that are leaking blood. \n\nOur body can fix this because it's a giant pump and filtration system. As the broken bits heal our body is continuously pumping blood/fluids through and around the healing area which break the bruise (leaked blood) down and put it into the filtration system to be cleaned."
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70jn7q | why is it that people tend to walk around aimlessly while doing tasks that only require hand involvement (such as brushing teeth or being on the phone)? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/70jn7q/eli5_why_is_it_that_people_tend_to_walk_around/ | {
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"The tasks u describe ten to be monotonous and tend to be dull. Walling around breaks up the boring action and serves as a distraction.",
"It's not aimless, people are distracted by the activities mentinoed, so they're looking for threats. It's hardwired. Watch a dog or cat bed down, they're looking for threats."
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b1fmxf | why are there always a bunch of super long infomercials on tv only at hours when no one would be watching tv? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/b1fmxf/eli5_why_are_there_always_a_bunch_of_super_long/ | {
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"You think because you're not watching no one is watching? Shift workers, insomniacs, parents up with sick kids, etc. There are *plenty* of people with TVs on at those hours.",
"Those are the cheapest slots of time.",
"It doesn't cost the television station much to broadcast a signal. What costs more is creating content or licensing content (for example - buying the rights to air reruns of an old show).\n\nIf the TV station does not think they will make enough money selling commericals to make up for the costs of creating or licensing the content, then they'll sell the entire block of time to the advertisers and let them fill it up with a big long commericial. The cost of generating the ad is all on them and the station just does the broadcasting.\n",
"The airtime is cheap for advertisers because it's the dead of night, and the networks don't have to pay for programming to run since the advertiser pays to produce the infomercial. And the type of people who are likely to get sucked into buying infomercial things are more likely to be awake at odd hours.",
"TV Shows don't pay for airtime, they're the filler between paid ads. \n\nThat filler is only worth what kind of viewers they drive. Late at night, it's a very small pie to be fighting over - but it is a very particular demographic. \n\nSo, instead of paying millions to produce a show that nobody wants to watch and sell ads nobody wants to buy, you can just sell the whole block to a company that has a product that doesn't sell well in 30s blocks. \n\nNobody's watching late night TV because they *want* to, it's just what's on. So they're locked in, up for some reason, and giving their attention away for free. What a great time to talk about life insurance, depression, and get rich quick schemes. ",
"Those time slots are cheapest.\n\nALSO, infomercials are trying to get you to buy something that you probably don't need. When are you more likely to comply - when you're well-rested, or when you have insomnia?"
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3s2w2e | what goes into mens' cologne that makes them smell "manly". what about these fragrances/chemicals makes them masculine? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3s2w2e/eli5_what_goes_into_mens_cologne_that_makes_them/ | {
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"All colognes are solutions made up of a solvent or base (often ethanol) that holds one or more solutes, often but not always plant essential oils. The solutes and their relative ratios are what give each perfume or cologne its own distinct scent. \nMen's colognes contain an ingredient called phallinone that is not present in perfumes for women.\n\n C-C-C-C-C~~\n | |\n C-C\n \n Phallinone\n\nThe double tilde indicates a free bonding site where another molecule may attach, which happens as often as possible as phallinone readily bonds with almost anything. The entire molecule is normally depicted as a \"ball and stick\" model, but Reddit doesn't support that so I'm making do.",
"It's contextual. In western culture most women's perfumes have fruit, flower, and vanilla notes. Men's cologne generally have earthy notes like pine and musk. \n\nBy context you think of it as smelling one way or another because you've always associated certain smells with perfume and others with cologne. ",
"Honestly it's mostly advertising, like with Axe products saying \"YOU WILL HAVE LITERAL SHIPMENTS OF VAGINA DELIVERED TO YOUR DOOR IF YOU USE OUR SHITTY SPRAY.\"",
"Female perfumes will usually be fruity, florals, gourmands (vanilla, sugary, edible smells) and male ones tend to be aromatic (oak moss), woody or spicy with musk, leather an tabacco as common notes. ",
"Good question. My guess would be that it's the same reason the color blue is considered for boys and pink for girls.",
"It's difficult to explain this simply, so I hope I won't bore any of you.\n\nIn academic philosophy, there's this problem called the \"explanatory gap.\" For example, doctors can define pain as the firing of certain nerves in our body; but defining what pain is does not explain what it feels like to be in pain.\n\nIn a similar vein, we can define the masculinity of cologne, or the femininity of perfume, as the product of certain chemicals or fragrances; but defining what masculine cologne or feminine perfume is made up doesn't help explain why people think certain smells are masculine or feminine. There's a lot of theories, however:\n\n1) Through repeated, intense association with others, one cannot help but associate certain symbols to sensations if those associations are there. The problem is that (1) doesn't explain the origin of those associations, but only how those associations take place currently.\n\n2) Certain smells might reproduce, evoke, or respond to some sort of biological considerations that came with natural selection. In other words, certain smells or fragrances might signal certain biological features that are innately attractive on men or women.\n\nanyways, I'm doing a lot of armchair thinking, so don't quote me on any of this."
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q5p7o | why turkey invaded cyprus in 1974 | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/q5p7o/eli5_why_turkey_invaded_cyprus_in_1974/ | {
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"There were tensions between Greek Cypriots and Turkish Cypriots ever since the Greek island was conquered by the Ottoman Empire in 1574. After WWI when Cyprus came under British colonial rule, Turks were given the choice to leave the island or live as British subjects. The British inflamed the tensions between Muslims, Christians and secularists and played up the nationalist tensions between Greeks and Turks. As a result of the Ottoman empire trying to regroup and influence the region a Greek nationalist group was formed in the 1950s that began a bloody conflict between Greeks and Turks. After nearly twenty years of low grade civil war and numerous deals, constitutional rewrites, and a US supported military junta that installed a Greek government, Turkey finally re-invaded Cyprus in July 1974, four hundred years after the initial conflict began. [Wiki](_URL_0_)",
"Military junta in Greece encouraged a coup in Cyprus. Turkey was a guarantor of Cyprus and used this gave them the right to send in their troops. No one could force Turkey to withdraw their troops after that because of cold war afterwards. "
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2m5twy | why does the nhl have teams from more than one nation? | This has never made sense to me. If NHL is made up of Canadian and American teams, shouldn't it be the North American Hockey League? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2m5twy/eli5_why_does_the_nhl_have_teams_from_more_than/ | {
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"_URL_0_\n\nThe NHL started out as a Canada-only league. They grew, teams moved & other leagues were absorbed but they never decided to change the branding.\n\nWhen logic & tradition go head-to-head in sports, tradition usually comes out on top.",
"Same reason the NFL will probably have a Toronto team within 10 years or so. \n\nNot as bad as when the Canadian Football League had a few American teams. "
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5q15mp | aside from signing executive orders, what power does the president actually have to force mexico to pay for a border wall? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5q15mp/eli5_aside_from_signing_executive_orders_what/ | {
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"Theoretically you can threaten tarrifs on their goods if they don't pay and offer them trade deals if they do. That's about the only real power short of war. If they don't pay either we build it and pay for it or we don't build it."
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1vditb | why does grass still turn brown and die in southern states during the winter, despite it still being warm with plenty of precipitation? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1vditb/eli5_why_does_grass_still_turn_brown_and_die_in/ | {
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"Dormancy in plants is influenced by the amount of daylight moreso than the temperature but they do work together. Though warm, the plants are able to \"sense\" the shortened amount of daylight and go through their dormant period. I keep saying daylight, but it is really the length of the night that is detected. \n"
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6puk43 | how safe are carnival amusement rides compared to the big corporations like disney and six flags? | I don't trust carnival rides at all, but I see rides at Disney being more safe. Are they equally as dangerous? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6puk43/eli5_how_safe_are_carnival_amusement_rides/ | {
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"Disney rides will be safer, no doubt. They are stationary, so are not being deconstructed and rebuilt regularly. Each time, a misplaced bolt or loose bolt could cause a malfunction in the ride. Disney have more money to spend on repairs and inspections. They probably spent more money on design as well. Plus Disney has a huge reputation to uphold, if they allowed an accident to happen it would be a disaster for their public relations. They simply cannot afford to have an accident because it would be worldwide news, so their maintenance plan will likely be much more stringent. \n\n[Here is an example of a high-profile theme park accident in the UK, despite having no deaths it caused significant losses for the operator.](_URL_0_)",
"Carnival rides are much more dangerous and they often have falsified safety inspections and carry no insurance."
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"http://www.thisismoney.co.uk/money/markets/article-3109943/Alton-Towers-crash-wipes-100m-owner-s-value-looks-set-lose-millions-lost-bookings.html"
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3ca33a | why does muscle grow back bigger after being broken down, and why do we suffer injury after prolonged use instead of massive growth to compensate? | I've lifted for years and have a basic understanding of what happens after a workout, but I'm not sure I really understand why it happens, or what prevents it from over-happening. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3ca33a/eli5_why_does_muscle_grow_back_bigger_after_being/ | {
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"Injury and growth are different. When you work out or even just when you use your muscles, they tear like when you stretch fabric or something. Your body does its best to develop and avoid future injury or pain, so the muscle grows back a little bit stronger to prevent it from happening again. It is the same way that your hands will get tougher if you play guitar or use them a lot. It is the bodies way of 'future proofing'. \n\nAn injury is different because it is the result of pushing your muscle past its breaking point. When it finally does repair itself, it goes back to close to its original size because the tear was too great. Think of muscle as tight fibers. When you work out, it's almost like the fibers are given a bit of space and can grow out a bit to fill the gap."
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aiwhln | why does warm/hot air feel thick and colder air feel thin and breezy? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/aiwhln/elif_why_does_warmhot_air_feel_thick_and_colder/ | {
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"Warm air can hold a lot more moisture that cold air. The excess humidity can impede the evaporation of sweat and thus result in stuffy, claustrophobic feeling. \n\nI'm always shocked at the feel of getting off a cool, air conditioned plane, and into the hot, sticky air of a tropical climate. ",
"[Warmer air is actually a lot less dense/thick than cold air](_URL_0_). It might not *feel* that way, but a cold headwind is *much* more difficult to cycle/run in than a warm headwind."
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8184sv | how do websites like whitepages acquire my information? | Also, as a younger person with a limited online presence, how do I retain my online anonymity? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8184sv/eli5_how_do_websites_like_whitepages_acquire_my/ | {
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"Generally by buying or data mining it from a large variety of other sources.\n\nThat said honestly you can't really maintain total anonymity (or rather the amount of effort to do so is so immense for the vast majority of people it isn't worth it). Have you googled something recently? That's data. Visited any news sites recently? Data. And as you get older you run out of choices as college, apartments, and banks generate some form of online connection to you.\n\nYour goal therefore should not be to maintain total anonymity, but rather to maintain relative anonymity. Don't put your email, phone number, or name on something unless you are sure you want everyone to know. Decide whether you want everyone to see a picture you post (and where you were when you took it due to geotagging).\n\nIf you don't want everyone to know, don't put it online, that simple, and educate yourself on how much of your data can be discovered easily (hint, it's more than you think).\n\nLuckily as humans we do have one big advantage here, which is that the majority of people aren't going to use your data maliciously. The vast majority of people don't want to track down your address and murder you, and could care less."
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4iwxow | why hasn't nasa sent cyanobacteria or antarctic lichen to mars yet? | _URL_0_
Cyanobacteria and the lichen were put into a simulation of martian soil and thrived! Why hasn't NASA actually tried this for real? I understand that it would take a while and a lot of it, but didn't Cyanobacteria pump enough Oxygen into the Precambrian Earth air to create the oxygen abundant atmosphere we have now? Why not start terraforming now? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4iwxow/eli5_why_hasnt_nasa_sent_cyanobacteria_or/ | {
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"The worry is contamination. NASA spends a great deal of time preparing their spacecraft, even unmanned ones, to be sterile. The concern is that should these spacecraft land or collide with something, the earth life will contaminate whatever is there and ruin any environment before we have a chance to study it.\n\nIt's a small chance, but there is an ethical reasoning for it, just in the same way that researchers don't blunder into isolates tribes if humans, but study from afar when possible.\n\nAlthough there is no proof of life on Mars, we worry that if we did do as you suggest, any life there might be threatened by the introduction of earth life.\n\nIn addition, Mars might be too small to hold onto a meaningful atmosphere, and there might not be enough carbon dioxide to sustain life there, even if the soil can.",
"If there is life there that we haven't discovered yet, we don't want to contaminate it. Also, earth organisms could possibly out compete the native life and we'd have nothing to study. They go through a lot of trouble to make sure the rovers and probes are sterile and free of biocontamination. ",
"Scientists are still looking for life on Mars. Putting life there will mess up that search. It would mean that if life was found, we would then have the problem of determining if it was natural of if we put it there. Space agencies across the world go to great lengths to ensure interplanetary probes are sterile."
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169n3l | why sharing too much information on sites like facebook, twitter, etc. is said to be so dangerous | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/169n3l/eli5_why_sharing_too_much_information_on_sites/ | {
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"text": [
"Because of identity theft. If I have enough information about you, I can pretend to be you, get a credit card in your name, and buy a whole bunch of crap that I don't have to pay for but guess what - you will still get the bill, and it will show up on your credit report.\n\nAlso pedophiles.",
"Sites like Facebook and Twitter have 3 very unique characteristics that you must consider very carefully if you want to protect your privacy.\n\nSpeaking in a general sense:\n\n1. Anything you input or share on those sites could--and probably will--be there forever.\n2. Anyone in the world could see it, and\n3. it is very easy to find you and identify your stuff.\n\nThe combination of those three characteristics is something that we've never seen before in human history. Before, the stuff you wrote or said had a limited shelf-life (photos fade, printed ink fades, magnetic tapes wear out, people forget). Or it had a limited audience (your friends, family, neighbors, trusted persons.) Or you could easily conceal who you were, by putting something out there with no way for people to know it was you who made it.\n\nSites like facebook and twitter preserve your stuff forever and ever (and they are *extremely* good at it.) They make it so your stuff is *potentially* visible to *anyone* with a computer and an internet connection. And make it impossible to post something without leaving some kind of identification.\n\nSince it's such a new and unique concept, there are many people who do not know, do not care about, or cannot handle the implications of that. It requires you to think a little more carefully about the information you share on those sites, because it could be there forever, it could potentially be seen by anyone, and anyone who sees it will know you put it there.\n\nUnderstand that any information you share about yourself could be used against you. That's the nature of the society we live in. What makes sites like facebook and twitter unique are the combination of characteristics I mentioned above. I don't know of any other information-sharing medium that has quite the same combination.\n\nDoes that mean you should avoid them altogether? Of course not; hundreds of millions of people use them every day with no problems. Are they dangerous? That depends entirely on you; how dangerous are the secrets you keep, if they were to get out? How could people use those secrets against you?"
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cv91qc | why are small bugs not afraid to fly directly up to humans/other animals that are much larger? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cv91qc/eli5_why_are_small_bugs_not_afraid_to_fly/ | {
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"Unless it's required for their survival (mosquitoes) then it's simply because they can't possibly know any better.",
"Bugs do not have the brain capacity human do and do not experience what you would call fear. They are mostly just driven by instinct.\n\nMosquitoes need blood to procreate so they are driven to get blood and have young and die. That's just what they do. No emotion.",
"I'm no expert on this, but I doubt whether small insects are even aware of the fact that these big \"things\" are alive just like they are, let alone recognize that big animals could be a threat.",
"The first reason would be its very rare that large mammals feed on flying insects. \n\nSecond, Most large mammals cannot effectively kill small flying insects. The may be able to shake or have tails, but in general there is not much danger to the insect.\n\nThird, there is usually a need for the insect to do it. Mosquitoes and some flies feed on blood. Many flies are looking for a place to lay eggs. \n\nFinally, from an evolutionary standpoint, risky behavior for a single fly is very different than risky behavior forna single human. Because humans (and most mammals) reproduce slowly and take a long time to mature, a single death is much more important to the species as it represents a large investment of energy and resources. For insects who may lay thousands of eggs and mature and live very quickly, a sungle death is less important. Even if some insects die (and a lot will) it only takes a small number to bring the population back up, so there isnt an evolutionary advantage to \"playing it safe\"\n\nIt has been a pretty good evolutionary strategy until humans came along. Even after humans, it still works for them given how many flies and mosquitoes are still around.",
"Bugs do not feel fear, or happiness, or anger, or Joy, or excitement, or sadness. They are automatons, and they react to stimuli automatically and without reflection or thinking of any kind. Their behavior has been programmed through millennia of survival and adaptation, and if a little bug flies up to a larger animal, it is because that behavior has led to the long-term survival of the bug as a species. When that behavior no longer enhances survival, it will be weeded out, and those bugs will no longer do that.",
"We aren't much of a threat. It's pretty hard to kill even a fruitfly out of the air. Compared to their time frame of reference we are basically not even moving."
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7668t7 | if trade is good for the national economy, why do some countries adopt protectionism? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7668t7/eli5_if_trade_is_good_for_the_national_economy/ | {
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"While free trade helps the country *as as whole,* certain specific groups of people may be terribly hurt. Protectionism is a way of defending those groups (say, people who make cloth) even though it comes at a cost to everyone else.\n\nIt's not efficient, but it does have at least one intended effect."
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63d9q6 | during the paleocene eocene how did animals survive in the polar regions? | I understand that the paleocene eocene was very warm and there were hippos, plants and large mammals living in arctic regions. But how did the animals and plants cope with the darkness in winter? Did they hibernate or migrate? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/63d9q6/eli5_during_the_paleocene_eocene_how_did_animals/ | {
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"There's two aspects to this. Primarily, Plants were Adapted for the particular growing season (at least where they grew) and the light present during the summer would have been enough for them to do all of their growth and reproduction. \nAs for the animals, animals don't explicitly need sunlight, and many cope without it with ease. The issue would have been the presence of plants to make up the base of the food chain, and the growth of the plants would have been sufficiently completed during the time when the sunlight was available to fulfill this role.\nThe temperature that allowed the plants to grow in the more polar regions would have done so by allowing them to metabolize at the ambient temperatures, thus allowing them to always do photosynthesis. If you've ever grown a plant inside without exposure to sun you've probably seen that they can grow quite well if there's continuous light, even if it's the relatively weak artificial kind.\nThe thing to remember about ecology is that it's taken as an entity over the course of the year, not day by day."
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336z91 | why is superman and other heroes wearing their underwear outside their pants? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/336z91/eli5_why_is_superman_and_other_heroes_wearing/ | {
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"Having briefs that are a different color than the suit itself is a way to break up the solid color of the suit. There's no actual reason for Superman to choose to wear briefs on the outside of his costume, it's just a decision on the part of the artist.",
"I remember seeing somewhere that it was because back in the days they were created real life strong men and body builders wore their breifs like that. I don't remember my source, but maybe someone else can back me up on this? "
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5z82d4 | why do materials like glass and ceramic shatter, and is it possible to cut them without them shattering? | This question is more about ceramics than glass, since I know glass can be cut but I don't think I've ever seen someone cut say, a ceramic pot in half. What is it that makes pottery unable to be cut after its been hardened, and is it the same reason as glass? If so can you cut ceramic in the same method as glass? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5z82d4/eli5_why_do_materials_like_glass_and_ceramic/ | {
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"Yes ceramic tiles are cut all the time. They make special power saws to cut them. The blades are diamond coated and they have a stream of water that covers the blade so it stays cool. ",
"Ceramics and glass are both considered 'brittle' materials and they are that way because of the way the atoms are stacked. It takes less energy to displace an atom the way they are stacked in brittle materials than it does in a ductile material. So you can brake it more easily.\n\nYou can cut glass with heat, because the atoms end up stacking differently when glass is a liquid and it becomes more ductile."
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fxogur | what is a miscarriage is and how does happen? | i understand its when a premature child embryo passes inside the womb, but how does it get out? what do they do with it? im confused about those things. a couple family members of mine have had miscarriages, so i dont intend to offend anyone its a genuine question | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fxogur/eli5_what_is_a_miscarriage_is_and_how_does_happen/ | {
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" > but how does it get out?\n\nThat depends how late it is into the pregnancy. If it's early enough then it will be dissolved back into the body or ejected. If it's later then it has to be surgically removed.",
"A miscarriage is when a foetus dies in the womb before a certain number of weeks, usually 20. After 20 weeks it is called a stillbirth instead. \n\nIt is usually diagnosed when no heartbeat is seen on ultrasound. Sometimes there is bleeding and pain but not always. \n\nOnce it is diagnosed, there are three options: do nothing, give medication or perform surgery. \n\nIf you do nothing, the foetus will eventually pass out of the vagina the usual way. You can also give medicine to cause “labour”. Or if this medication doesn’t work you can go for surgery, which involves a suction device into the vagina. Some women choose to go for surgery first rather than the drugs because it’s quicker and less distressing. \n\nThe foetus can be disposed of in two ways - the family can receive the remains and arrange a burial or cremation or whatever they want to do with them. The second option is for the hospital to dispose of them which is by incineration. \n\nUsually, and especially in recurrent miscarriages, the remains are sent for pathological and genetic testing to try to find out the cause of the miscarriage. They are then disposed of or returned after these tests are done.",
"A miscarriage is the death of an embryo or fetus inside the uterus before it is developed enough to survive outside. How it comes out depends on how far along it is. Early miscarriages just come out of the body like a period. In fact, many early miscarriages are actually mistaken for periods. Miscarriages that happen later usually have the contents removed surgically using the same equipment used for performing abortions."
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1khe5o | when i get an x-ray, why does everyone else have to wear some kind of protection or leave the room but i'm all good? | I was just at the dentist and curious. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1khe5o/eli5_when_i_get_an_xray_why_does_everyone_else/ | {
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"The risks of things like x-rays are cumulative - the risk of receiving 1 x-ray is negligible, but if you had 20 of the things per day, over your entire career, the risks would multiply.\n\nSo it is safe for you, because you are only having one. But the radiology nurse or dentist is present for many of them, so they need to be protected."
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7v7g2x | how are radioactive rocks formed? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7v7g2x/eli5_how_are_radioactive_rocks_formed/ | {
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"Do you mean the kind of rocks that we can determine an absolute age for using radiometric dating methods? They naturally contain certain isotopes (isotopes are the name given to atoms of the same element that differ in mass due to varying numbers of neutrons in their nucleus) which are radioactive, and we can exploit this in certain cases to calculate how long since those isotopes were sealed off in a 'closed system' ie. how long since the mineral they are in cooled off enough to stop exchanging any atoms with melt or solid rock (solid state diffusion is a thing - slow, but exchange of atoms between two solids is perfectly possible). \n\n\nAnyway, like I said some isotopes just happen to be unstable, which means they will radioactively decay into certain other elements. We can measure the difference between the amount of parent isotope left and the amount of daughter isotope present and use it to back calculate a date. As well as being based on fundamental physics and mathematics, what can really make such calculated ages so reliable (within the error bars given), is that you can often run this sort of test on the same rock unit or even the same mineral within a rock for more than one different radiogenic system - there are many, and no, carbon-14 is pretty useless to geologists as that's barely scratching the surface in terms of how far back it can be used for. The gold standards are pretty much te different uranium-lead decay systems or the potassium-argon decay system for certain samples. \n\n\nTo bring this back a bit, the point is that our planet has a certain set of ingredients in the form of the different chemical elements, and a certain proportion of them happen to exist in a variety of isotopes, some of which are radioactive. Let's take potassium (K) as an example as it is a relatively common element on Earth, particularly in the crust, and therefore it's in all the surface rocks and environments we know and love. Most potassium consists of the stable isotope ³⁹K, but about 0.01% of it today is the radioactive isotope ⁴⁰K which has one more neutron than ³⁹K, and whose decay to argon is much used in radiometric dating. It has a half life of ~1.2 billion years, which is quite handy for geologists who study the whole of Earth's 4.6 billion year history. Note that we can make calculations based on several half-lives, so that we are not just limited to 1.2 billion years (about 7 or 8 half-lives is the limit before measurements start getting unreliable). \n\n\nRadioactivity is a natural aspect of life on Earth then, and we have evolved to live with a certain amount of background radiation. I'm sure you've also heard that bananas are a source of potassium, so every time you eat a banana, a very small percentage of the potassium being consumed will be those radioactive isotopes. ",
"Other post here has a great explanation of how radiometric dating works, but to TL;DR it for you: stars form them, particularly when they explode at the end of their lives. Everything radioactive in the Earth was either made in a star, or something made in a star has broken down over time into that radioactive material. Or put in a more Earth-centric way: they've \"always\" been here. It was part of the Earth Starter Package."
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6mp5sc | why do fleeing bugs choose to jump on people's faces instead of somewhere actually safe? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6mp5sc/eli5_why_do_fleeing_bugs_choose_to_jump_on/ | {
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"It's warm and sweaty. But that's not much of a reason for lots of bugs.\n\nConfirmation bias may also play a part in this. There might just be bugs *all over the place*, but you only notice the ones that land on your face.",
"maybe they weren't utilizing the \"flee\" portion of fight or flight?\n\nMMT",
"Bugs aren't smart. They just go. They don't know what a face is, much less a human face. When they want to flee, they just go fast.\n\nThey also have really bad vision. A housefly, with its compound eyes, basically sees the whole world pixellated, so in order to actually see something, they have to get close."
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2vcqco | charcoal is made from wood, and wood is a renewable resource, so why can't we burn charcoal for energy instead of regual coal? | edit: *regular | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2vcqco/eli5charcoal_is_made_from_wood_and_wood_is_a/ | {
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"It's extremely inefficient in terms of energy in to energy out ratio. It's not impossible or anything, just not a really good idea on a large scale. ",
"Its a very dirty way to make fuel. Anthracite coal is dirty, charcoal is worse. ",
"Coal is much more efficient to burn. Also trees absorb (sequester) CO2 and burning wood releases the CO2 into the atmosphere. Not that coal doesn't release CO2, but it makes more sense to burn coal."
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xwkn6 | please explain death by exhaustion. | i was watching some documentary about over exercising and they showed a few people who died of exhaustion, some of them were over weight some of them werent. wouldn't they just pass out first and use the energy from the fat stored in their bodies before they die? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/xwkn6/please_explain_death_by_exhaustion/ | {
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"In short; hydration.\n\nYou work you sweat. You work in the sun, you sweat more. You need water to replenish the fluid you lost through sweat (or urine). Water is around 50% of your blood. You lose enough of it, your blood becomes more viscous (solid like), it won't move through, you're tissues and organs won't have enough blood to replenish them and die. There are many other factors involved, such as electrolytes (Sodium, Potassium, Chloride, etc) but if we're talking in general terms you're probably dying due to loss of hydration.",
"I've come very close to heat stroke before during a strenuous fast march, and the feeling is sickening. I ended up in a medical center on a drip.\n\nFirst, you sweat, a lot. I mean, my boots were filled with 2-3 cups of sweat each. Your sweat gradually gets less and less salty as you lose sodium, so you'll be able to taste the difference.\n\nThen, you stop sweating. You actually run out of water to sweat out. And this is where it gets bad. With no water left in your system, you stop radiating heat. Heat just builds up inside of you until you shut down.\n\nYou throw up and cramp all over as you're dangerously low on electrolytes. You actually lose control of all your muscles, it's a weird feeling. You get a terrible headache and start talking incoherently rolling around on the floor.\n\nIf i had kept going I might have gone into heat stroke but thankfully I had medical attention nearby."
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4wy9zl | what is procedural generating in the game no mans sky? how does it work and does it allow for the sheer amount of unique animals and planets to be created within the game? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4wy9zl/eli5_what_is_procedural_generating_in_the_game_no/ | {
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"The key word is procedural, as opposed to random. They've got equations that generate a heightmap for a planet, probably with various further procedures to simulate weathering, tectonics, and the like (If X section of surface is next to a river, run erosion simulator on it and check again, etc.)\n\nThen it adds Flora and Fauna which are similarly generated (Spoiler alert, most of the life in no man's sky is basically lego stuff, so randomly mold a torso shape like playdough, do a quick check to make sure it's not *too* weird, then stick legs and arms and whatever randomly selected doodads on it to make it unique.\n\nBasically it's random but with checks and balances. The program probably checks planets at each stage like \"this one has a crack in it that reaches all the way to the core, reject and start over, this one the ocean is fifty miles deep but only five miles wide, reject and start over, etc.\" then if it gets through all the checks it makes it. This lets them make a ton of planets very quickly, but they all tend to look kind of the same aside from color scheme and flora and fauna.\n\n"
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a4eo5r | what are the senses that people have besides the obvious five? | What senses do people have besides taste, touch, smell, hearing, and sight? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/a4eo5r/eli5_what_are_the_senses_that_people_have_besides/ | {
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"Proprioception is a pretty cool one - being able to sense the positions of your limbs. Balance/acceleration would be another very distinct example.",
"One of the most obvious yet often overlooked is our sense of balance, maintained in the ear but still distinct from hearing, as even deaf people still have balance typically. \n\nOne of the simpler ones that's extremely important is your sense of timing, the ability for you to keep and maintain a steady rhythm. Without this, coordinated movements would be extremely difficult and walking would be essentially impossible. \n\nMy personal favorite is proprioception, your ability to tell where your body is relative to itself. It's what allows you to close your eyes and still touch your finger to your nose; your ability to judge where your body is in space without the other senses. \n\nThese are just a few examples and not a comprehensive list. Some argue that there are 20+ senses that we utilize, but that largely comes down to how you specifically define a sense. These examples are just a few of many overlooked senses that fall into most definitions of what a sense is. ",
"acceleration\n\npain\n\ntemperature\n\nstimulation\n\nbalance\n\ngravity\n\nfamiliarity - deja vu\n\nproprioception"
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14hn6t | how we measure the measurements themselves | How do we know exactly how much a kilogram weighs or how long a metre is? What do we define them against? Also, bonus points, how were they defined before modern science? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/14hn6t/eli5_how_we_measure_the_measurements_themselves/ | {
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"First keep in mind that units are arbitrary - they don't have any impact on the results of experiments. Units are just a way to put a number to \"that far\" or \"this long\" or \"this much.\"\n\nWith that being said, units:\n\n-The second is defined by to be 1/the frequency of the light emitted by a particular process in cesium-133.\n\n-The meter is defined to be the distance that light travels in 1/299,792,458 of a second.\n\n-The kilogram is weird, in that it's defined to be the mass of a hunk of stuff called the International Prototype of the Kilogram (IPK). This is actually slightly problematic because the IPK is losing a small amount of mass over time.\n\nUnits have gone through lots of evolution over time. For example, the second used to be defined in terms of the Earth's orbit. And a long time ago, people used very awkward units like the cubit, which is defined to be the distance between the elbow and the tip of the middle finger. Obviously that's not a very good unit system because it varies from person to person.",
"If you have a pendulum in a clock, the length of time it takes to swing depends on the length of the pendulum. A pendulum that swings for one second is a metre long.\n\nIf you could have a cube of water that measured 10 x 10 x 10 centimetres, that would be a litre of water. \n\nA litre of water weighs one kilogram\n\nIf you heat up a millilitre of water by one degree Centigrade, the energy used would be a calorie.\n\nI am sure there are more equations but I can't think of them off the top of my head.\n\n"
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a7jyeg | why is sleep such a great hunger suppressant? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/a7jyeg/eli5_why_is_sleep_such_a_great_hunger_suppressant/ | {
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"Im not an expert, and do not claim to be one. But my personal experience is that if Im super hungry and go to bed, I wake up the next day not feeling hungry at all and am able to carry on without food for a long period of time. \nWhat i think happens is that our bodies generally need significantly less energy whilst sleeping. So you dont or wont actually feel hungry while sleeping. And when you wake up the next day, its a new day and your body resets itself.",
"I'm no expert here, but generally your body needs fuel and rest to function properly. Your sleep affects certain hormone levels. Some of those can have an effect on your appetite. There are a few hormones that can increase or lower your appetite. When a body is sleep deprived, it will signal the body to release more of the hormone that increases appetite and it can also send out hormones to suppress the hormone that lowers the appetite. On top of that you will feel like you have no energy after not sleeping, which typically people will want to eat to get energy back. I've had my fair share of all nighters, so I've looked into this a little. Fun fact, sleep deprivation has been shown to increase the chance of becoming overweight and obesity. So moral is try to get those 7-9 hours of good sleep."
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4j48v4 | what is the function of the "net" under the basket (basketball)? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4j48v4/eli5_what_is_the_function_of_the_net_under_the/ | {
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"It also makes it easier to tell whether ball went through rim or not. If you've ever played with no net, sometimes a swish going Clean through looks a lot like a close airball.",
"* it makes it more clear whether the ball has gone through the hoop\n* it slows the force of the ball and directs it downward, so you don't have to chase after it",
"It does two things. Helps determine if the ball went through the net. By seeing the movement and hearing the sound. Second making the ball drop more downward so it's easier to get the ball. ",
"What everyone else is saying, PLUS; have you ever tried to shoot on a hoop with no net? It's surprisingly more difficult to target the exact spot you want to shoot the ball. A net makes it easier for a shooter's vision. ",
"The net used to be closed, to actually catch and hold the ball. Before that they were actually wooden boxes. Getting the ball out of the net slowed the game down greatly, then either a vandal got to a net or someone had the bright idea to cut it open.",
"Oh you mean the basketball ring?"
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4iwqi6 | how did words such as "like" become fillers in speech? are there other words in other languages that do the same, and how did they come to be? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4iwqi6/eli5_how_did_words_such_as_like_become_fillers_in/ | {
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"Linguistic fillers are present in every language. [Here](_URL_0_) is a list of fillers from different languages. What words become those fillers is the surrounding environment (trends). Once exposed to those words frequently in conversation, it's simply a matter of subconsciously forming the habit. Even people known for their public speaking ability do this (e.g. Obama tends to start an answer to a question with \"look...\", and Reagan did this with \"well...\").",
"Fillers are used to signal that you haven't stopped speaking yet, so that the person you're speaking to knows they shouldn't interrupt.\n\nIn a sentence like this: \"It was like a purple colour,\" the speaker is using \"like\" in more or less its original meaning of \"similar to\". As a filler, \"like\" came to mean, \"I can't think of the exact word right now, but it's similar in meaning to this word.\" After that I suspect it was a fairly small jump from there to, \"Wait a split second while I think of the word I need at this point.\" And then in some places it acquired new meanings: an utterance like, \"I was like, awesome!\" means: \"My reaction was to declare it awesome.\"\n\nAnd there are many other fillers in English: uh, um, well, so, and many others. And other languages also have fillers. For example, a language I know extremely well, German, has these:\n\n* ähm / öhm / öh (all meaning \"uh\" or \"um\")\n* also (meaning \"so\")\n* tja (at the beginning of a sentence, often indicating an admonishment or perhaps cynicism)\n* nun (meaning \"now\")\n* ja (literally \"yes\", sometimes used to add emphasis)\n* halt (at least in some dialects, certainly in the south)\n\nTechnically, some of these are probably not fillers but what are known as \"modal particles\", but they do perform the role of filler at least sometimes.",
"Well in finnish the word used as a filler word as \"like\" is, is \"niinku\" or \"niiku\" or, in a bit fancy way, \"niinkuin\". In swedish there is \"liksom\". All these words being used as filler words is not the only thing they have in common, since they all mean the same thing: \"like\" is used to describe that thing A is *like* thing B. Thing A is *niinku* thing B. Thing A is *liksom* thing B. I think it might have something to do with that, but i have no idea about the other filler words.",
"Others have given a good explanation, but here's a good example of what they do in French: \n\n\"Bonjour madame, uhhhhhhhh, ça va? Uhhhhh la nuit dernière j'ai uhhhhhhhh rêvé de uuuuuhhhhh toi.\""
]
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2fqvu1 | why do british roads have wiggly lines? | like this one:_URL_0_ | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2fqvu1/eli5why_do_british_roads_have_wiggly_lines/ | {
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"There's a nearby pedestrian crossing. It both indicates you should slow down and that you shouldn't park there (since it obstructs pedestrian vision).",
"White zig-zag lines indicate the approach to a pedestrian crossing. It is illegal to stop or park on white zig-zag lines. This offense can be enforced by the Police as well as the local council (councils are responsible for the majority of parking enforcement in the UK).\n\nYellow zig-zag lines can be found outside the entrances to public buildings such as schools and hospitals. These are placed to indicate no parking or stopping but this is only enforceable if the council has enacted a Traffic Management Order to stipulate as such and there is additional signage by the roadside."
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9cz0gf | how does a home central ac work? does it use any water? | The more I google about how a central air conditioner works, the more confused I get.
I read that legionella bacteria is a concern with big air conditioning units, but only ACs that use a humidifier or cooling tower. I think just any ACs that use water can harbor the bacteria. I read that it’s a concern especially in large central air units, like those used in stores or office buildings. But I can’t figure out if the central air conditioners that people use on homes (with the big box outside the house) have a humidifier or a cooling tower or even use water at all.
Could someone explain how home central AC units work, whether they use water, and whether they are a risk for legionnaires disease? Thank you!! | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9cz0gf/eli5_how_does_a_home_central_ac_work_does_it_use/ | {
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" > I read that legionella bacteria is a concern with big air conditioning units, but only ACs that use a humidifier or cooling tower.\n\nThe idea here is that if the bacteria are in the water and the water is able to become an aerosol in the air then people will breath in the bacteria and become sick.\n\n > Could someone explain how home central AC units work\n\nA fluid (not water) is used to transfer heat from inside the dwelling to outside. Heat can be thought of as the concentration of thermal energy in a given area, with great flowing from areas of high concentration to areas of low. The working fluid (something like freon) is compressed which takes all the thermal energy in it and puts it into a smaller volume, meaning it has a higher temperature. The heat then flows out of the fluid until it reaches equilibrium with the surroundings.\n\nThe fluid is then pumped into the dwelling and allowed to expand, reducing its temperature as the concentration is reduced. Heat then flows into it until equilibrium and the cycle repeats, pumping heat out of the home.\n\nEach of the steps where the heat is allowed to flow out or into the fluid is aided by radiators and fans blowing across them. The fluid itself isn't exposed directly to the air and it wouldn't be something the bacteria could grow in anyway, so it isn't a danger.",
"First, lets talk legionella. This is a water borne bacteria that can cause some serious health issues. Fortunately, as you saw, it's not a concern for small scale air conditioning. \n\nHome ACs use a refrigerant (Freon used to be it, R410 i believe is the current rage). This is a chemical that boils/condenses at very specific conditions of temperature and pressure. There are a few components to the home AC.\n\n1. Condenser - this is the big box outside. It consists of a fan, coils, and a compressor. The refrigerant flows through the coils and enters the condenser as a gas, gets compressed, and the heat is blown away by the fan. This is why when the unit it running the air coming off the outside unit is quite warm. This also condenses the refrigerant into a liquid.\n\n2. Evaporator- this is the unit inside. It consists of tubes and the air handler. The air handler is basically another fan that blows the warm air from inside your house across the tubes holding the refrigerant. This causes the refrigerant to evaporate and cool down the air before it is passed to your house. This also drops water out of the air and reduces the humidity. The refrigerant is now a vapor which gets passed back to the condenser.\n\nIt's the same cycle your refrigerator goes through to keep your food cold.\n\nFor large scale units, it's usually more efficient to use water cooling rather than a compressed refrigerant. This is where the legionella concern comes from. Instead of passing the water through a closed loop, it goes to cooling tower. There, the water falls through the air, shedding the heat, and giving off some vapor. In this wet, humid environment legionella can grow like gang busters.",
"HVAC tech here. If you are worried about bactiria when using a humidifier look into getting uv blubs put into your ductwork. Kills mold and bacteria.",
"An air conditioner works by circulating a fluid between two heat exchangers. There is a cold one inside of your ductwork and a hot one outside. A heat exchanger is a coil of tubing with fins on it. It trades heat between the fluid inside with air until they are the same temperature. \n\nYou can manipulate the fluid's temperature by changing its pressure. Increasing the fluid's pressure will increase its temperature, and decreasing the pressure will lower the temperature.\n\nA compressor compresses the fluid and makes it very hot. This hot fluid goes through the outside heat exchanger to cool down to the temperature of the outside air. \n\nThen this high pressure fluid travels through pipes into your house where it passed through an expansion valve. The expansion valve only lets a little bit of fluid through at a time, causing the other side to have a low pressure and becomes very cold. The cold fluid goes into the inside heat exchanger where it trades heat with the air inside your house. The air becomes colder and the fluid becomes warmer.\n\nThe warmed, low pressure fluid goes back outside through another pipe and returns to the compressor to start the cycle again."
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3un3ui | would transferring your consciousness and memories to a new body even work, or would it just create a second you? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3un3ui/eli5would_transferring_your_consciousness_and/ | {
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"Sci-Fi loves this stuff. So do philosophers - I think Derek Parfit is a good guy to read on this one; but his work builds on stuff by earlier thinkers like John Locke.\n\nIt's usually labelled 'continuity of identity' or something similar. Your answer to the question might be determined by whether or not you take the continuous mental states/memories of being one person as the important factor that determines whether or not you are the same person. Others might argue it's the physical cells of the body that matter in determining continuity.\n\nPeople do genuinely worry that using some form of teleportation might actually result in the death of a person, only to have a radically different person emerge on the other side. \n\nIt makes sense to me to think that if you were to clone a person; then both of those people have a claim on being the original person, though their personal timelines diverge from each other at that point, so they become two different people from then on.",
"That entirely depends on your definition of what makes \"you.\"\n\nRegarding your example: \nAre you still you when you trim your nails? \nI think so. \nAre you less if you've had a limb amputated? \nAFAIC sill the same person.\n\nSo where does that stop? As you remove portions of the physical body when do you stop being you?\n\nIs it when you stop breathing or your heart stops beating? \nWhat about people on life support, are they still themselves?\n\nIf you can take it this far and eliminate any biological ties then what's left? \nIs it memories and experience? \nLikes and dislikes? \nIs it the way you speak or carry yourself? \n\nIf you can clearly define and prove what \"you\" are then there would be lots of people interested in discussing that with you.",
"There is a book, Noggin, by John Corey Whaley, that somewhat describes this, I guess? It definitely is very interesting. Essentially, a kid gets cancer, and then gets cancer everywhere but his head. So he gets his head removed and cryogenically stored for a few years. Then, he gets a \"donor body\" from someone who had cancer in the brain, I think. Anyway, its about his life after getting a bigger, better body, essentially. Iirc, the doctors answer this same type of thing.\r\rtl;dr Noggin, by John Corey Whaley, answers this type of thing, and is also a very good read. "
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1k7g37 | can i have electricity going through my body, and not feel it? | I just did a Mcgyver and repaired my laptops charging device (notice my expertise in the terms.) And it works! but i am afraid that my computer is filled with electricity and as i'm writing this i have electricity in my body. Is it possible that i have it without feeling it?
Can a wrongly repaired cable instead transmit the electricity all over my body through the computor? Thank you | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1k7g37/eli5_can_i_have_electricity_going_through_my_body/ | {
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"While it might be possible, it isn't hazardous. You would feel the sensation if anything were exposed. \n\nGenerally if you have a frayed or damaged power adapter, you're more likely to cause sparks/etc. where the adapter plugs into the computer- the electrical surge though would be contained to the parts of your computer that conduct electricity (allow it to pass through). This is almost entirely the circuitry of your machine (this is why you should never work on the physical innards of your machine unless you have unplugged it and removed the battery first). \n\nThe case of your computer doesn't directly touch the parts that conduct electricity, and generally insulates (does not allow electricity to pass through).\n\nShort answer: your body is a conductor - you allow electricity to pass through you. However, you're not at risk unless you're grabbing for an exposed part of your cable or something that is directly being powered. Your keyboard, case, and everything you should touch should be fine =)",
"The human body is conductive, and thus it can have electricity flowing through it. In fact, there is constantly electricity flowing through it, as your nerves work via electrical signals. If the current flowing through your body is DC and/or very small, you won't feel it. AC current will give you a tingly or vibratory feeling. If either current is large enough, you'll be burned."
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2kkg2t | how do magnetic forces affect everyday life and the universe as a whole? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2kkg2t/eli5_how_do_magnetic_forces_affect_everyday_life/ | {
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"Well, I don't want to attempt to be exhaustive, but let's just list a couple of examples:\n\nNatural:\n\n* solar wind (charged particles) are steered away from populous areas and directed toward the poles by the Earth's magnetic field. This spares us a lot of background radiation and impact on telecommunications. Up north, you can see the effects in the aurora borealis.\n\n* migratory animals, ranging from butterflies to whales, use the earth's magnetic field as a directional guide. So do ants.\n\n* pulsars, which emit beacons of high-intensity light over billions of light years, generate their focused beams with magnetic fields.\n\nMan-made:\n\n* almost every electric motor ever made uses magnetic fields.\n\n* every made-made radio, microwave, and light transmission uses magnetic fields, often generated with electric currents. This ranges from XM radio to supermarket checkout scanners.\n\n* hard disk drives in computers are magnetic storage."
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8efvva | why do forehead pimples disappear faster than cheek pimples | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8efvva/eli5_why_do_forehead_pimples_disappear_faster/ | {
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"I'm not a professional but I believe it's because your cheeks are a much more traveled place for your hands and food, thus comes into contact with more oil. There's also more fat in your cheeks than your forehead, giving the pimple more room to hide and reform."
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1w35tr | how was pi discovered? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1w35tr/eli5how_was_pi_discovered/ | {
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"Pi goes way back. The constructions of the Egyptians indicate an understanding of Pi. Archimedes invented a way of calculating an estimation, instead of relying on measurements.\n\nSo Pi was known in the earliest of the written records.",
"Initially, it was done through geometry. If you think about a stop sign, it's sort of round-ish, and it's also very easy to calculate the circumference of an octagon. If one were to double the number of sides (16 instead of 8) it would appear even more circular. Ancient mathematicians simply kept calculating the circumference of more multi-sided, circle-like polygons until they were able to come up with a ratio that was close enough to pi to be put to practical use.",
"BetterExplained has a [great explanation]( _URL_0_ ) of how Archimedes derived the value of pi to 99.9% accuracy over 2000 years ago.",
"Take a round object and measure its radius or diameter. Then measure its circumference - say, with a tape measure, or a piece of string.\n\nDo this with round objects of several sizes. Divide the circumferences with the diameters. Congratulations, you've discovered pi.",
"1. take a string of known length\n2. shape it into a circle. circumference of circle = length of string.\n3. diameter of circle is ALWAYS related to the circumference by the same number--pi. i.e. circ/diameter always equals the same number--pi.\n\nIt wouldn't take humans long to notice that. ",
"It's funny, an awful lot of mathematicians believe pi was \"incorrectly\" defined, and that we should have given special meaning to the value of 2pi. Check out the [Tau Manifesto](_URL_0_) for more info.\n",
"A lot of the comments here answer it pretty much spot on, but if you do want a bit more info a really good book called Alex's Adventures in Numberland has an excellent section on the discovery of Pi and a whole load more. [Here](_URL_0_) is a link to the section on Pi in the book.",
"[pi is exactly 3](_URL_0_)"
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5j9wh9 | how did dubai make so much money in such a short period of time? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5j9wh9/eli5_how_did_dubai_make_so_much_money_in_such_a/ | {
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"Two things: Dubai opened up its economy to foreign investment, in a region that was mostly either insecure or closed off. \n\nSecond thing: despite the recession dealing a blow to the economy in 2008 onwards, they had already built the infrastructure to make cash - hotels, malls, airports etc. So when the Arab Spring hit many surrounding countries , Dubai and the UAE stood as islands of calm in a sea of chaos.",
"1) sell oil\n\n2) employ workers at almost nothing if they are immigrant workers\n\n3) make the place look amazing for vacations and kings so they have vacations hosted for super-rich people"
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6adq5c | the nba draft lottery | I understand it's the 14 teams that didn't make the playoffs but I don't understand how it's really only the top 3 through the lottery. Also I don't get the 4 combination thing to devide the top 3 | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6adq5c/eli5_the_nba_draft_lottery/ | {
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"The NBA (and NHL) use a lottery system to determine the order of the draft to discourage teams from \"tanking\", or intentionally losing games once they know that they won't qualify for the playoffs. Otherwise, teams may even be willing to tank all season long if they believe that the first overall pick might be the next Jordan or LeBron.\n\nIt works almost like a normal lottery, teams that don't qualify for the playoffs are assigned combinations of numbers like lottery tickets. The lower you finished in the standings, the more tickets you get. The worst team has a 25% chance of winning, the best non-playoff team has a 0.5% chance. \n\nAs for why only the top three picks are decided that way, I would guess that it has something to do with making sure that teams can only fall so far from their expected draft pick. The lowest pick that the last place team could expect is 4th overall. This happened to the Colorado Avalanche of the NHL this year."
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1txlwj | why are fiscal conservatism & social liberalism mutually exclusive? | I've read articles stating that most Americans lean towards a conservative economic policy, and it's obvious that the country as whole is generally becoming more open socially (eg gay rights). It would seem that a political platform combining both would have mass appeal, yet I've seen no such stance from any party that I know of. Why is this? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1txlwj/eli5_why_are_fiscal_conservatism_social/ | {
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"They're not. Libertarian Socialism or Left Libertarianism exist. And there are several very small parties that have a platform with that type of ideology or close to it. \n\nI'm currently most interested in hearing what [these guys](_URL_0_) have to say.",
"There is such a political platform: [Libertarian](_URL_2_)\n\nLibertarians are pro-civil liberties on all major social issues, while having a largely laissez-faire position on economic issues. Libertarians believe the government should stay out of people's business, both personally and economically (because your income *is* your life in many respects).\n\nNote that Libertarians don't consider political thought to be strictly left wing vs right. They see the main choice being between freedom and Statism, and both the traditional left and right wings have elements of both.\n\n[The Advocates for Self Government](_URL_0_) is an organization that promotes libertarian philosophy. They offer [The World's Smallest Political Quiz](_URL_0_quiz/quiz.php) which features just ten general questions to gauge where you stand.",
"The issue isn't that those two ideas must be mutually exclusive. The problem is that the system in the US is set up so that only two main political parties can reasonably exist. This is a result of the \"first past the post\" voting setup in America--the candidate with the most votes wins the election. Thus, people are forced to vote strategically--not necessarily for their favorite candidate. CGP Grey has a series of videos about this topic on Youtube; they're really good and you should check them out.\n\nSo, since we only have two major political parties we have to take every issue and give one side to each party. If you want to support a candidate who more nearly matches your beliefs then you can support a third party. Many may claim that this is \"throwing your vote away,\" and in a sense they're right--your candidate will almost certainly not win if you support a third party candidate--but it does have an important effect. If lots of people are supporting a 3rd party then one of the 2 main parties will generally modify their platform to absorb those voters. However, voting for a 3rd party candidate can cause a spoiler effect--your favorite main-party candidate may lose since your vote went to a candidate who won't win. "
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c72mw4 | why are human eyes so bad with sunlight that we need sunglasses to operate normally? bright sunlight doesn't seem like a new phenomenon for humans to deal with. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/c72mw4/eli5_why_are_human_eyes_so_bad_with_sunlight_that/ | {
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"Your eyes adapt to the light around you. 10,000 years ago people spent most of their day walking in the sun, so their eyes had plenty of time to adapt. \nNow we spend lots of time indoors where it's darker. Your eyes need time to adapt again to the outdoors, and given that we go inside and outside quite frequently, sunglasses make it much easier."
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606eaw | does a bullet reach its maximum speed as soon as the gunpowder explodes behind the slug? when is it at maximum speed, and how long is it accelerating for? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/606eaw/eli5_does_a_bullet_reach_its_maximum_speed_as/ | {
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"Maximum speed is at the muzzle, also known as muzzle velocity. After it leaves the muzzle, there is no more force to accelerate the bullet and the bullet will drop and slow down due to gravity and air resistance, respectively.\n\nSimilar concept to throwing a ball, where the ball is susceptible to the forces of air resistance and gravity.",
"The bullet accelerates along the whole length of the barrel. It reaches its maximum speed at the instant it leaves the barrel."
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4eoazj | 1+1=2 took 162 pages to prove in the principia mathematica. why? what did betrand russell need to prove first? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4eoazj/eli5112_took_162_pages_to_prove_in_the_principia/ | {
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"First you have to define '1,' '+,' \"=,\" and \"2.\" That's where the difficulty lies, in defining the concept of value and addition in order to prove that 1+1=2 rather than treating it as an axiom. ",
"It took longer than that, actually: that's to the famous \"from this it will follow, once addition has been suitably defined, that 1+1=2\". The proof is completed rather later, in Volume 2, with the (far more amusing, to me) comment \"the above proposition is occasionally useful\". The bit in between is mostly defining addition. They do actually use it later: to prove that x * 2 = x + x, and in proving induction. But yeah, take a look at (some of) the proof, if you're interested: it's all free online in the University of Michigan Historical Math Collection. ",
"Well, let me write a proof that 1 + 1 = 2:\n\n S0 + S0 = S0 + S0 Identity is reflexive: a = a\n S0 + S0 = S(0 + S0) Peano's axioms: a + S(b) = S(a + b)\n S0 + S0 = SS(0 + 0) Peano's axioms: a + S(b) = S(a + b)\n S0 + S0 = SS0 Peano's axioms: a + 0 = a\n\nThis proof is using [Peano's axioms](_URL_0_), which as you can see, take a few screenfuls of text to explain. The gist of it is that in Peano's axioms, the concepts of addition and multiplication are constructed out of the **successor relationship**—the concept of \"the next (natural) number\". So in Peano arithmetic, we write numbers like this:\n\n* The number zero is written as the digit `0`;\n* If `a` is a number, then `Sa` is the **successor** of `a`—the number that \"comes next\".\n\nSo doing things that way, 1 + 1 = 2 comes out as `S0 + S0 = SS0` (\"the number that you get when you add the number than comes after zero to the number that comes after zero is equal to the number that comes after the number that comes after zero\").\n\nI also did *not* explain the whole reasoning, because at every step I made use of the transitive property of equality (if a = b and b = c then a = c), and general rules of logic (e.g., start with the \"obvious\" proposition that `S0 + S0 = S0 + S0`, and rewrite it to equivalent ones until you get the target proposition.\n\nAnd note that Peano's axioms work only for the arithmetic of natural numbers—if you're dealing with fractions, or square roots, or pi, they're not enough. Whereas Russell was trying to develop a system that would work for **all of mathematics**. If all Russell wanted to do was prove 1 + 1 = 2 he wouldn't have needed all of those 162 pages.",
"The Principia Matematica was the joint effort of Whitehead and Russell to reduce arithmetic to pure logic, as was Frege's dream (and before them, Leibniz's).\nThe thing is, to do this, a formal language must be constructed, which is then used to express and work on those mathematical properties.\nRather than using the common '=', '+', '-' symbols, the problems are expressed with the different set of symbols of this new language.\nOnce the language is constructed, a set of axioms and rules of inference are proposed, with which one could potentially prove all provable mathematical truths within the system.\n\nThe proof for 1+1=2 is just an example of said set of truths.\n\nThat overhead in pages is not in what they needed to prove first, but in the construction of the formal system used to prove that truth.\n\nIf you are interested in the subject, I recommend you read The Universal Computer from Martin Davis. It tells the story of the development of formal logic trough snippets of the lives of great mathematicians who contributed on it's creation. \nAnd more importantly, it does so in an accessible language.",
"In computer programming there is an equivalent to 1 + 1 = 2 that has been written in every language ever created. We call it \"Hello, world\".\n\nIn essence, it is a program that prints or displays the words \"Hello, world\" and exits without doing anything else. It usually looks something like this:\n\n #include < stdio.h > \n \n main(){\n printf(\"Hello, world\");\n }\n\nIt's pretty simple at this level and takes seconds to explain. The \"#include < stdio.h > \" line tells the compiler that we need basic input and output functions. \"main()\" is the standard name for the start of the program in this language/platform. \"printf(\"Hello, world\");\" dumps the string \"Hello, world\" to the basic input/output that we asked for with the #include.\n\nThat simplicity comes from already having a compiler (with linker and assembler), a basic I/O library, a defined language syntax, an operating system, a monitor, a microprocessor, transistors, printed circuit boards, wires, a wall outlet, power lines, power generators and some sort of energy source like coal or a large lake behind a dam.\n\nThe Principia route to \"Hello, world\" starts with a bucket of sand and a pile of rocks with useful metals in them.",
"Why not just read it and see for yourself? :)\n\n_URL_0_\n\nThere's a PDF download link (29Mb) off that page. Also available in eBook formats. Enjoy!",
"For a more up-to-date version of *Principia Mathematica*, see the [_URL_9_ website](http://us._URL_9_/mpeuni/mmset.html). It's a hyperlinked and machine-verified set of proofs that includes all of *Principia* [and more](_URL_7_).\n\nIt starts with propositional calculus (rules of logic, like \"if not A. then A implies B no matter what B is\"), then set theory, then defines numbers in terms of sets.\n\nBecause metamath defines integers are a subset of the complex numbers, and in fact [defines \"2\" as \"1+1\"](http://us._URL_9_/mpeuni/df-2.html), the first non-trivial addition is [2+2=4](_URL_3_).\n\nThis is theorem #8952 in the list. Although it doesn't depend on all of the previous 8,951, it does depend on 2,451 of them! Metamath also lists the 29 axioms and 39 definitions that this depends on. The longest logic chain back to an axiom is [150 steps long](_URL_8_).\n\nDoing it the way *Principia Mathematica* is simpler. [The equivalent theorem in metamath](_URL_1_) is #7256, and only depends on 24 axioms.\n\nBut just to give an idea of where it starts, here are the first few statements. Lower-case Greek letters (𝜑, 𝜓, 𝜒, etc.) are \"well-formed formulas\", essentially any logical statement. Lower-case Latin letters (a, b, c, etc.) are sets, upper-case Latin letters (A, B, C, etc.) are \"classes\" of sets, and other symbols are introduced explicitly.\n\n1. [dummylink](http://us._URL_9_/mpeuni/dummylink.html), a way to introduce redundancy while writing proofs that is not used in completed proofs.\n2. [idi](http://us._URL_9_/mpeuni/idi.html), a second way to introduce redundancy while editing a proof.\n3. [wn](http://us._URL_9_/mpeuni/wn.html): Syntax definition: if 𝜑 is any well-formed formula then ¬ 𝜑 is also a well-formed formula. (This introduces the symbol \"¬\").\n4. [wi](http://us._URL_9_/mpeuni/wi.html): Syntax definition: if 𝜑 and 𝜓 are well-formed formulas, then so is (𝜑 → 𝜓) (\"𝜑 implies 𝜓\"). (This introduces the symbols \"→ \", \"(\" and \")\". Note that the parentheses are part of the definition!)\n5. [ax-1](_URL_4_): The first real axiom: (𝜑 → (𝜓 → 𝜑)). Called \"the principle of simplification\" in *Principia Mathematica*, it basically says that a statement implies the same statement with a condition. E.g. if water is wet, then if the sky is blue, then water is wet. (Also, if fire is cold, then if the sky is blue then fire is cold. The statements don't have to be true for this to work logically. Try working it through as a truth table, for all 4 possible combinations of 𝜑 and 𝜓.)\n6. [ax-2](http://us._URL_9_/mpeuni/ax-2.html): The second real axiom: (𝜑 → (𝜓 → 𝜒)) → ((𝜑 → 𝜓) → (𝜑 → 𝜒))). This is a sort of distributive law. It's true in the other direction as well (((𝜑 → 𝜓) → (𝜑 → 𝜒))) → (𝜑 → (𝜓 → 𝜒))), but that's [theorem #351](_URL_0_).)\n7. [ax-3](_URL_6_): The third axiom of propositional calculus: ((¬ 𝜑 → ¬ 𝜓) → (𝜓 → 𝜑)). Called \"the principle of transposition\", negating statements reverses the direction of implication. E.g. if \"if the sidewalk is *not* wet, it's not raining\", then \"if it's raining, then the sidewalk is wet.\"\n8. [ax-mp](http://us._URL_9_/mpeuni/ax-mp.html): *Modus ponens*: Given 𝜑 and (𝜑 → 𝜓), we may conclude 𝜓.\n9. [mp2b](_URL_5_). The first actual *theorem* that's proved, as opposed to a definition or axiom that's simply asserted. It's a double *modus ponens* implication: Given 𝜑, (𝜑 → 𝜓), and (𝜓 → 𝜒), we may conclude 𝜒. This shows you how metamath presents a proof. Each step is either one of the three hypotheses, or another theorem (or axiom) applied to a previous step.\n10. [a1i](http://us._URL_9_/mpeuni/a1i.html): Axiom ax-1 in inference form: Given 𝜑, we may conclude (𝜓 → 𝜑). This is not the same thing as ax-1 itself, because although we informally describe \"→\" as \"implies\", that's just a nickname. The actual *meaning* is defined by the axioms. In this case, we apply *modus pollens* to the hypothesis (𝜑) and axiom ax-1 (𝜑 → (𝜓 → 𝜑)), to reach the desired conclusion.\n\nIt goes on like this, in teensy tiny steps (step #401 is the [law of the excluded middle](_URL_2_)) and finally builds a large chunk of mathematics."
]
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"https://archive.org/details/PrincipiaMathematicaVolumeI"
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"http://us.metamath.org/mpeuni/pm5.41.html",
"http://us.metamath.org/mpeuni/pm110.643.html",
"http://us.metamath.org/mpeuni/exmid.html",
"http://us.metamath.org/mpeuni/2p2e4.html",
"http://us.metamath.org/mpeuni/ax-1.html",
"http://us.metamath.org/mpeuni/mp2b.html",
"http://us.metamath.org/mpeuni/ax-3.html",
"http://us.metamath.org/mpeuni/mmset.html#theorems",
"http://us.metamath.org/mpeuni/mmset.html#trivia",
"metamath.org",
"http://us.metamath.org/mpeuni/wi.html",
"http://us.metamath.org/mpeuni/wn.html",
"http://us.metamath.org/mpeuni/idi.html",
"http://us.metamath.org/mpeuni/df-2.html",
"http://us.metamath.org/mpeuni/ax-mp.html",
"http://us.metamath.org/mpeuni/dummylink.html",
"http://us.metamath.org/mpeuni/a1i.html",
"http://us.metamath.org/mpeuni/mmset.html",
"http://us.metamath.org/mpeuni/ax-2.html"
]
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||
10hnbl | why do people bother charging, say, $6.99 when they might as well charge $7? | Why the 1c discrepancy? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/10hnbl/eli5_why_do_people_bother_charging_say_699_when/ | {
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"It's a psychological phenomenon that can be called \"price attractiveness\".\n\nEssentially, when someone sees a price tag, they see the first digit, and ignore the rest.",
"When you want to emphasize value, you say it's 6.99, when you want to emphasize quality, it is 7 dollars.",
"Working in a grocery store, i can assure you it makes a difference. People will look at the 6.99 and think \"oh, around 6 dollars, what a decent deal\" but if they were to see the $7, the would think \"oh it's 7 dollars, the other store is around 6 dollars so it's a much better deal.\" The moral is, people are easily manipulated.",
"Aside from the psychological \"price attractiveness\", it used to form a better-than-nothing method of forcing retail staff to register the purchase properly. \n\nIf a customer bought 1 item at $5.00, it is fairly convenient for the customer to just hand over an even $5 and the employee to just pocket it and bid the customer farewell. Pricing that forces the employee to use the register (for change or totalling) has naturally always been strongly preferred by employers.",
"Even numbered prices make people think \"Quality\"\n\nOdd numbered prices make people think \"Value\"",
"Apart from sounding cheaper, there is a second reason for the 1c. \n\nStore managers wants the cashiers to give change to all customers. If a purchase comes to a round number say $5, and the customer hands over a single note, it is too easy for a cashier to pocket it but when it's $4.99 he has to open the cash register to get a penny and it forces him to enter the purchase. ",
"I think I'm the only person that this psychological tactic doesn't work on.\n\nWhen I see x.99 I think how 99 sounds like such a lot. But when I see a clean £7 it looks neat, tidy and small.",
"TL;DR: To trick people."
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fjmmhf | how come the body doesn’t see the ink from a tattoo as a foreign object and try to attack/get rid of it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fjmmhf/eli5_how_come_the_body_doesnt_see_the_ink_from_a/ | {
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"The body does recognize the pigments in the ink as a foreign object and does try to get rid of it. This is why tatoos fade. The problem is that some of the pigments are physically too large to be transported away as there is not enough room between the cells to squeeze the pigment between them. They will therefore be left in place. They may be slowly broken down and there may be some openings as the cells rejuvinate to allow the pigments through but this is a very slow process that takes decades before the tatoo is visibly fading.",
"The body does respond in this way. It attempts to deal with the foreign body of the ink particles in two ways. 1) surrounding it with fibrous scar tissue, 2) attempting to surround and slowly haul the particles into the lymphatic system. \n\nIn the Case of 2), the pigment particles are simply too large, and it's like an ant trying to move a teapot. \n\nOver time the ink particles are slowly moved deeper into the skin which causes tattoos to blur and fade.\n\nLaser tattoo removal takes advantage of this process. \n\nIt uses extremely short but extremely intense pulses of light. The total light energy of each pulse is low, but it's compressed into a period of time so short that it stretches the imagination a bit. Usually it's around 300-400 trillionths of a second. \n\nWhen such brief but intense light is absorbed by the surface of the pigment, it causes powerful electromagnetic forces there which result in a shock wave propogating through the particles. This pulverizes them into much smaller fragments. This action also breaks up the capsule of scar tissue surrounding the particles by extension. Because the surrounding skin is mostly transparent compared to the pigment, the living tissue tends to be mostly unaffected because it doesn't absorb much energy from the pulse, except by the force of the imploding pigment. \n\nCertain skin cells called melanocytes which produce dark skin pigment may be killed, which can cause skin lightening as a side effect. As I mentioned the overall energy is low, similar to shining a flashlight on your skin.\n\nOnce the pigments have been broken up into much smaller pieces, thet can be absorbed by immune system cells and transported to the lymph nodes, spleen, and kidneys. \n\nThe analogy of ants is a good one here. If you can imagine ants trying to chew up and carry away a dinner roll, they'll have a hard time of it because of the sheer size difference, and due to the hard outer crust. But if you dry out the roll then crush it into crumbs, then ants won't have much problem dragging off a pile of crumbs, piece by piece.",
"After having my tattoo for 16 years my body has started attacking it as if it is foreign. When my seasonal allergies act up my tattoo swells and itches. The ink raises as if it is brand new."
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1sx0s1 | what's the deal with the narwhal bacon thing? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1sx0s1/eli5_whats_the_deal_with_the_narwhal_bacon_thing/ | {
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"[Here](_URL_1_)\n\nand [here](_URL_0_)\n\n"
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"http://imgur.com/DsxvJJv",
"http://www.reddit.com/r/AskReddit/comments/98mm8/hey_reddit_im_redditing_from_the_denver/c0bt710"
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c2woh8 | in an action film, the hero climbed on top of a fast moving train, then jumped forwards from one carriage to the next to get to the front of the train. is it possible in real life, and whats the physics behind it? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/c2woh8/eli5_in_an_action_film_the_hero_climbed_on_top_of/ | {
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"ern3uv0"
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"text": [
"Yes it's possible. The only thing making it difficult would be the rushing air pushing you back."
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|
c0v37f | iuds... i understand what they’re used for, that there are two kinds, but i want to know how/why they work. what is the mechanism behind them and how do they act as a contraceptive? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/c0v37f/eli5_iuds_i_understand_what_theyre_used_for_that/ | {
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"**Hormonal IUD:** These work by messing with your hormones just enough so that your ovaries don't release eggs when it's time to ovulate. Depending on IUD, it may not prevent the ovaries from ovulating. Another way, then, is that the hormonal IUD thickens the mucus in your uterus, thereby slowing down sperm. It's like asking someone to swim across a pool of water versus a pool of honey. The thickened mucus makes it harder for the sperm to \"cross the pool\" to the egg.\n\n**Copper IUD:** Sperm don't like copper and die when there's too much copper in the uterus. In fact, the copper sort of \"decapitates\" the sperm. It's like Gandalf saying, \"You shall not pass!\" The egg's still there, but the sperm can't get to the egg because the copper's killing them off in their journey.\n\nSo one acts on egg-release in the ovaries, and the other acts on sperm that try to swim to those eggs.",
"Hormonal IUDs release a constant stream of hormones, similar to the pill, but localised, and sort of trick the uterus into thinking it's pregnant. They are hormone based, so someone sensitive to hormones might experience some sode effects (hormonal acne,...), but make periods lighter and potentialy nonexistent. \n\nCopper IUDs basically kill the sperm, but also irritate the uterine lining, making pregnancy near impossible, come with a high chance of heavier periods and cramps, but are non hormonal and don't influence anything else. \n\nBoth are generaly a reliable contraceptive option, the one who has them doesn't need to remember to take a pill every day, making less room for human error, but after being inserted might cause cramps and pain, and might need to have the strings shortened (if felt during penetrative sex, for example)"
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2g2s7h | what is polyester? | Every clothing item, bedding, basically everything is made out of polyester...but it all feels different. What is polyester? On google it says that it's made out of esters...what is an ester? How come polyester materials all feel different? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2g2s7h/eli5what_is_polyester/ | {
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"An ester is a molecule with a specific small chunk of it in a certain configuration. Most \"life\" molecules have a set of atoms that largely includes carbon (C), oxygen (O), and hydrogen (H) in them, plus some other elements. Certain configurations of these three create certain classes of molecules. For example, alcohols have an OH cluster jammed in them, but fuels like gasoline have only C's and H's. Esters have a couple O's jammed in them that are connected to a C. You get them in fruits and candies (where they make that classic banana smell), and they're in your DNA as the parts that set up your genetic instructions.\n\n\"Poly\" means many (polygon = many sides, for example), and a Polyester is an ester molecule with a huge number of atoms attached to that COO group. The long length of the molecule and its chemical properties means it converts into fibre easily, which is why it is used for many fabrics and clothes. And because those polyesters can be woven into threads of various thicknesses, and that thread can be woven together and processed in various ways, the cloth that comes from them can feel very different, heavy for furniture cloth but light for a t-shirt."
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5tzqgd | why are americans so upset over russia influencing the election when they influence elections around the world all the time? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5tzqgd/eli5_why_are_americans_so_upset_over_russia/ | {
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"text": [
"Same reason a mobster is mad one of his crew gets killed when they kill people all the time."
]
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||
8rtpz1 | why does a plastic straw rise out of diet, no ice, but stays put with ice in the drink? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8rtpz1/eli5_why_does_a_plastic_straw_rise_out_of_diet_no/ | {
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"The straws act as nucleation points for the formation of bubbles. These growing bubbles sticking to the sides of the straw from surface tension add their buoyancy to the straw which can lift it some out of the drink. The presence of ice can press on the straw enough to keep the minor change in buoyancy from moving the straw though."
]
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||
37wjie | how is hiring private military contractors cheaper then using the regular forces yet everyone in a pmc makes three times the money as a soldier? | ELI5: How is hiring private military contractors cheaper then using the regular forces yet everyone in a PMC makes three times the money as a soldier? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/37wjie/eli5_how_is_hiring_private_military_contractors/ | {
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"When you have a full-time employee, you're on the hook for the long term. In the case of the military, they hire people for 3-4 year contracts. They have to pay for all the effort to recruit qualified soldiers, several months of training on a new soldier, full room & board, retirement pay, long-term health care, and tons of other things.\n\nWith a contractor, they're *only* paying for the time they're working. You can bring somebody in *today* for a single job & then let them go with zero long-term financial commitments. Yes, the cost per day is usually higher, but you're not paying for tomorrow.",
"For an awful lot of cases where the military or government hires contractors \"because private companies can operate more efficiently than the government,\" it turns out they AREN'T cheaper.\n\nContractors frequently come with all kinds of hidden costs and gotchas, but by the time governments figure that out, they're often trapped in long-term contracts they either can't back out of, or they won't because it would look bad politically for them, so they just keep slathering money on it.\n\nSometimes, saving money isn't even a consideration, it's just straight-up pork. When former Halliburton CEO Dick Cheney found himself in de facto charge of the US government at the start of his Splendid Little War in Iraq, he ordered fleets of dump trucks to deposit mountains of cash on Halliburton's doorstep, and then just said, \"party on, dudes!\" \n\nHalliburton and its subsidiary KBR were *everywhere* in Iraq, providing every kind of service imaginable...like building showers for US troops. Because they were operating more efficiently than the government, they cut a corner or two, and the showers came with the added bonus feature that they electrocuted the people who used them. After *more than one* US soldier was injured or killed by these things, they grudgingly fixed them, but only because the mother of one of the dead soldiers wouldn't stop whining about it.\n\nThere was very little accountability for how much Halliburton was paid or what they spent it on, but it's pretty certain they profited HUGELY from their former boss's little tea party.\n\nEven when corruption and no-bid contracts *aren't* an issue, contractors are STILL always seriously hampered by the requirement that they have to generate an ever-increasing profit to keep the stockholders happy. So they way they work is to cut corners. They slash employee benefits to the minimum, they use cheaper materials. Private prisons--as one example--cut down on the quality of the food they serve to inmates, cut down on the quality of the training of the guards, that kind of thing. No way THAT could go wrong.\n\nThis has also gotten to be a big thing in the intelligence world, there are an alarming number of private companies that are handling some of the most sensitive intelligence the country has. The way it works these days over at the CIA is you get hired, put in five years or so of training at government pay, then quit and walk back in the doors the very next day as a private intelligence contractor making many times your government salary.\n",
"Usually it's not cheaper. It's:\n\n1) politicians awarding contracts to their sponsors\n\n2) hiring contractors who can do untoward shit, be blamed, dissolve, rename themselves, and be back on payroll next time you need them (look up Blackwater, or Xi, or Academi, or whateverthefuck they call themselves nowadays)",
"It's not. The military can't hire engineers and experts at the prices that have been set for what they are allowed to pay by law.",
"Basic training is VERY expensive. A member of the military gets free food and shelter for the duration of their enlistment. (Many don't use it.) Also, vets get free health care for life at VA if wounded. Retirement bennies for 20 years service run into MILLIONS of dollars, esp for mid-level officers and senior NCOs. Government contractors don't get any of that.."
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1mev25 | the satisfaction some (including myself) get from picking a scab, peeling a sunburn, etc. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1mev25/eli5_the_satisfaction_some_including_myself_get/ | {
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"text": [
"Grooming instinct, .Removing something you feel should not be there."
]
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[]
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||
9ng2gj | why do humans roll around in pain? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9ng2gj/eli5_why_do_humans_roll_around_in_pain/ | {
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"text": [
"Rolling around generates a multitude of neutral sensations.\n\nIt is better that your brain should be filled with more sensations than solely agony."
]
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5drtxu | 5: can someone help me understand the concepts of bytes and bits? how are they related to each other, and why is 255 such an important number? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5drtxu/elif5_can_someone_help_me_understand_the_concepts/ | {
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"A bit is the absolute smallest piece of information that we can deal with in a digital system - it's either a 1 or a 0, it can't be anything else. A bit, for the most part, isn't much use by itself though, so we have to stick them together into something larger - and that's a byte, or eight bits.\n\nWhen we're dealing with them in groups of eight, we can do useful things with them. We can say, for instance that the eight bits in the sequence 01000001 are equal the the letter A, 01000010 is B, 01000011 is C and so on.\n\nHowever, we can also use a sequence of bits to represent a number. If you think about what our normal numbers that we'd use in everyday life mean, you'll recall that each position in a number represents something - for the number 123, it represents:\n\n1x 100 \n2x 10 \n3x 1\n\nNow, we can do that because we're using base 10, where every single one of those digits can be somewhere between 0 and 9. When you only have two digits, 0 and 1, that changes things, so instead of 100s, 10s and 1s, we have powers of 2 (i.e. 2 multiplied by itself a certain number of times):\n\n\n\n1 | 1 | 1 | 1 | 1 | 1 | 1 | 1\n---|---|----|----|----|----|----|----\n2^7 | 2^6 | 2^5 | 2^4 | 2^3 | 2^2 | 2^1 | 2^0\n128 | 64 | 32 | 16 | 8 | 4 | 2 | 1\n\nIf you add up the bottom row of the table, you'll get 255 - the reason it's so important is that it's the largest number we can represent in 8 bits.",
"The word \"bit\" is short for \"binary digit\". Binary is just a way of counting, just like the way you normally do. The difference is, instead of starting at 0, going up to 9 and starting over at 0 (with a 1 written to the left), the highest number you can have in one digit is 1. If you hit 1 and want to keep going, you put a 1 on the left and go back to 0. So a bit just a binary digit. It has two possible values: 1 or 0.\n\nWhy do we care? Computers. A computer is really just a very large collection of very small switches. By carefully arranging them, we can do math with them, and by carefully doing math, we can write words, and by carefully writing words, we can give a machine instructions, and it will do work for us. Each switch has two possible positions: on or off. So if you're trying to do math with 2-position switches, it makes sense to use a number system that has two possible values.\n\nNow of course we want to work with more information than just a single 1 or 0, and it's a real pain to count them all. So they needed to come up with a unit that could measure a bunch of bits, and one that made sense from the perspective of making words and instructions. A variety of different word sizes were experimented with, but they eventually settled on 8 bits as the standard. So that's all a byte is: a collection of 8 bits.\n\nWhy 255? Well, how many ways can we arrange 8 bits? One bit has two possibilities: 0,1. Two bits though, has four: 00,01,10,11. Three bits have eight possibilities: 000,001,010,011,100,101,111. Seeing the pattern here? Every time I add another bit, I multiply the possibilities by 2 again. Essentially, I keep raising 2 to a power that's one higher than the last. So what's 2^8? 256. But we start counting from 0, so the highest number you can represent with 8 bits is 255, or in binary, 11111111.",
"A bit is simply a zero or a one. Think of it like a light switch. The light can be off (zero) or on (one). \n\nA byte is simply a collection of bits that mean something. In the old days the number of bits in a byte wasn't agreed. Now a days we pretty much agree that 8 bits make up a byte. \n\nNow for why 255 is important. The way you normally could is base 10. Thinl back to school and when you did columns. The first column was '1's, the second column was '10's, the third column was '100's and so on. You counted from 0 to 9 in the first column then 10 was a 1 in the tens column and a zero on the ones column. \n\nBinary - counting in bits - is the same. In binary your columns are '1's, '2's, '4's, '8's, '16's, and so on. You count 0 to 1 in the ones column, but to get to 2 you need to put a 1 in the twos column. \n\nSo, now consider what this looks like with eight bits in a byte. \n\n128 64 32 16 8 4 2 1 (column val) \n\n 0 0 0 0 0 0 0 0 = 0\n\n 0 0 0 0 0 0 0 1 = 1\n\n 0 0 0 0 0 0 1 0 = 2\n\n 0 0 0 0 0 0 1 1 = 3\n\n 0 0 0 0 0 1 0 0 = 4\n\n 0 0 0 0 0 1 0 1 = 5\n\n\nAnd if we have all '1's\n\n 1 1 1 1 1 1 1 1 = 255\n\nThere is your magic 255.\n\n\n\n",
"bits are the basic units for software, think of them as the smallest part of the programs and applications.\n\nA bit is a binary unit wich means it can have two posible values wich are 1 and 0, now that sounds pretty limited knowing that a bit is the base of all software, so you may be thinking, how is it possible to create games and webpages and all the other stuff with only a thing wich represents 0s an 1s? well to do it we group this bits and then we interpret them to create more complex structures, the most basic of this agrupations is the byte.\n\nWhat is a byte? a byte is a group of eight bits, and why its 255 so relevant? well it is the maximum value wich can be represented using eight bits in binary system, in case you dont know binary system is a system in which values are represented using two values wich are 0 and 1 so in binary 0=0 1=1 10=2 11=3 100=4 and so on....\nand therebefore the biggest number that can be represented using eight bits is 11111111 wich equals 255\n\n\nSo the number is found in a lot of things because a byte is used to represent them, for example a IP address wich is used to connect to networks is represented by four bytes, they usually look like this: 151.101.193.140 every dot separates the bytes. and as you may imagine, the biggest IP address possible is 255.255.255.255\n\nIn short 255 is important because it is a standarized value.\n",
"255 is an important number in file systems because it is the max amount allowed for a name in most file systems. ",
"A bit is a binary digit, for example whether a switch is up or down, or whether a wire is on or off. It's either a 0 or a 1, as opposed to a decimal digit that can also be 2,3,4,5,6,7,8 or 9.\n\nA byte is a group of bits used to represent a larger value, for example a 2-bit byte can count to 11 (3), a 4-bit byte can count to 1111 (15), and an 8-bit byte can count to 11111111 (255). 8-bit bytes have been the standard for a pretty long time now."
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7mwb60 | when photons hit objects and then come back to our eyes, do they kind of just "bounce" off the object, or are they always absorbed and re-emitted by its atoms? | I was reading about the photoelectric effect, where photons are absorbed by atoms and then re-emitted. But I couldn't really find any information on when exactly this happens. Is that what happens every time light hits something and then reaches our eyes? Or do the photons with improper wavelengths not "fit" and get "rejected", thereby bouncing off and never being absorbed at all? Or is bouncing and re-emission basically the difference between color and shininess, like a pure white object re-emits all photons and a mirror bounces away all photons...or something? Idklol | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7mwb60/eli5_when_photons_hit_objects_and_then_come_back/ | {
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"You can picture the process as an absorption and emission, but things in the quantum realm work in ways we cannot easily imagine. Here's a simple depiction.\n\n\n\nPhotons are little pieces of energy: sometimes it looks like a ball, sometimes like a wave I the sea. If a photon encountering a molecule has the right amount of energy (if it isn't too big or too small), an electron in the molecule will accept that energy and become excited, frenetic with that extra energy. Soon after this excitation the electron will get tired and throw away that extra energy in a new photon, as big as the one it previously accepted. This photon may occasionally be directed towards the retina in your eyes and produce an image in your mind.\n\n\nBe aware that electrons are very choosy and won't accept all the photons, but only those with the right amount of energy. This is the reason why a banana is always yellow: its outer molecules have electrons that absorb and emit only photons with an energy corresponding to the yellow color. In fact, for a photon any amount of energy can be put into relation with a different color.\n\n\nThere are many processes in which photons are absorbed and emitted by an object, this is just one of them. Metals for example behave somehow differently, but this is a nice example.",
"Photons can interact with matter through:\n\n* Rayleigh Scattering\n* Thomson Scattering\n* Photoelectric Effect\n* Compton Scattering\n* Nuclear Pair Production\n* Electronic Pair Production\n* Photonuclear Interaction\n\nIf we're talking about normal everyday light we can focus on the first three only since the other interactions are either impossible or extremely unlikely.\n\nThomson and Rayleigh Scattering are both elastic. This means that the photon \"bounces\" off either the whole atom or one electron (Rayleigh and Thomson effect respectively) without losing any energy. For the photoelectric effect to occur, the photon needs to be energetic enough to ionize the atom, i.e. knock out an electron completely. This is much rarer to see in everyday life, since out of the sunlight spectrum, only the ultraviolet part is typically energetic enough for this process.\n\n"
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bhqslh | what causes iridescence? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bhqslh/eli5_what_causes_iridescence/ | {
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"A couple of ways. One is thin film interference like soap bubbles or oil film on water. The other is due to microscopic structures which act as diffraction gratings. Examples are some birds/insects, the green in sliced cooked beef or ham, and the rainbows from CD reflections. Interference is when some waves are cancelled and others are reinforced."
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7ut5j3 | how did they combine many old screens into one giant tv-wall back in the day? | Like you see some films, and you'd have an evil lair or some imposing cold-war bunker. And you'd have like 50 TV's hanging on a wall, most of the time they did their own thing, but in some cases all fifty TV's were connected to display one signal, extended across all the TV's in one big impressive image.
Nowadays with modern computers, it's pretty easy to connect a few screens to a single computer. But how did they do that back in the day before there were digital video ports and fancy computer OS's? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7ut5j3/eli5_how_did_they_combine_many_old_screens_into/ | {
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"Support for a multi-monitor setup is either achieved by installing multiple graphics cards into one computer or by special display controllers, that have the ability to feed multiple monitors independently with a signal. Monitors supporting DisplayPort allow driving multiple monitors from only one external clock. DisplayPort version 1.2 supports Multi-Stream Transport; this makes it possible to drive multiple displays on one single DisplayPort connector using a multi-head cable or loop through.\n\nFurthermore, multiple computers can be connected to provide a single display, e.g. over Gigabit Ethernet/Ethernet to drive a large video wall.\n\n_URL_0_ will tell you more and also has pictures of what they used.",
"In films, I'm pretty sure it was done with special effects. Without digital video, it is practically impossible to turn a bunch of TV's into a single display. You could use a bunch of cameras in an array and point that at an image. \n\nThese days, some monitors can do the processing for you. No PC needed, but the monitors are expensive (3-5K$). We use them in broadcast control rooms. ",
"\"Back in the day\" was only as far back as the late 1970s or early 1980s, and actually, they were using some of the first digital video hardware for that. These devices would take an analog signal, convert it to digital, manipulate it, and convert it back to analog again.",
"Before the 1980's multiple cameras was used to record video on to multi-track video tape, or to record to multiple laser disks that were synchronized on playback. Very cumbersome and not very practical. In 1986 Philips introduced the [Vidiwall device](_URL_0_) that could split a signal to multiple screens. "
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g1vvwl | what is the electric potential? i checked wikipedia but didn't quite understood... | I mean, i pictured like the top of a waterfall and the base of It, the top has potential of letting the water(the elctricity) flow down, instead the base has none, or less than the top. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/g1vvwl/eli5_what_is_the_electric_potential_i_checked/ | {
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"It's electrical gravity!\n\nIf you've got a waterwheel, you can generate energy by letting high elevation water fall down to a lower elevation\n\nThe high elevation water has \"potential energy\", or the energy associated with its position. \n\nAs water falls from \"high potential\" to \"low potential\", that \"potential\" energy is converted into \"Kinetic\" energy, or the energy associated with its motion.\n\nIf you have two magnets with both north poles touching, and you let go, they fling apart. Holding them in place is a form of \"potential\" energy. When given the opportunity, that potential energy will begin converting to \"kinetic\" energy as the magnets begin moving away from one another.\n\nWell, electric potential is basically the quantification of the magnet example. When you have two electrons pushed close together, they try to repel one another. If you keep up this repelling action, then you basically get the waterwheel analogy."
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43y7x7 | why does the united states have such a weak mental health care system and a general stigma against it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/43y7x7/eli5_why_does_the_united_states_have_such_a_weak/ | {
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"In the 1960's we came to realize that our mental institutions were generally terrible places full of misery and torment for the patients. We started closing these places down in an act that was seen as merciful for the patients. Unfortunately, plans to *replace* all these institutions with quality care facilities never materialized. They had intended to open up new institutions, but just never got around to it. As a result, jails have become the primary care facilities for the mentally ill. Their inability of mentally ill people to cope with society's rules lands them in institutions that place a priority on punishment over rehabilitation. If I recall correctly, at least a quarter of prison inmates are thought to be mentally ill and incapable of taking care of themselves in the real world.",
"Plus let's not forget just how messed up our criminal justice system is. We are addicted to incarceration, and are struggling with state budgets as is. I doubt much effort will go to mental health with everything else money isn't going to",
"There's a stigma against because people have a hard time understanding what they can't see. For instance someone with ocd might be unable to grab a door handle with their bare hand because they fear it's dirty and will cause them to get deathly ill. Someone without ocd sees this and thinks the person is weird and writes them off as such. They don't understand the true fear and anguish the person is being forced to go through. The person with ocd doesn't want to be gripped by such debilitating fear, but the way their brain works makes thoughts get stuck. It's not as easy as saying get over it, and many people with ocd understand that their thoughts are irrational but that doesn't always help. I also think the chronic nature of it can scare people. If someone has ocd they will always have it, even if they get better at dealing with it. It generally goes through periods where it gets much worse and that can be hard for many people to understand. ",
"Because a health care system like here in europe ( where everybody pays some amount into and everybody gets something out) is often stigmatized as socialistic. And Socialism was the great enemy in the cold war",
"JFK had a sister who was lobotomized and institutionalized in the 1940's , he played a large role in dismantling the system. ",
"From what I understand it's probably a fallacy to believe the US attaches a greater stigma to mental health issues than the rest of the world.",
"I'll throw out a few things others have not said. First off, most people want to help others, so do not listen to the people here saying American hate mentally ill people. People do hate when it is used as a criminal defense when it is obviously not the case; ie a drug dealer running a semi large distribution system but his lawyer claims his IQ is low he would not be able to button up his own shirt (I have seen that). \nLocal government health centers will help mentally ill, give then medication, but the patient will feel better and decide to stop taking their medicine (from friend who does this as a job). Also, the mentally ill do not always ask for help. So here is the problem, should the government be able to forcible medicate someone. Can the government pick someone off the street and medicate them etc. I don't know and and I feel this is a slippery slope that goes against all the US stands for. \n\nAlso I think there will be an increase in mental health spending from the mass shootings we have had. I just wish the government would tell us if these shooters were on any medications and what signs where missed.",
"the common american ignores that \"mental health\" issues even exist, since the concept that your brain can become physically or chemically sick and change essentially who you are is inherently awful and scary.",
"Everything is basically a business in the United States.\n\nUntil they can figure out how to monetize mental health care, it will continue to be under funded and under staffed.",
"im not sure why we look down on people who are attempting to get help, but the bigger issue is that people can't afford the help. Because we can not afford the help we need, people get worse and end up committing crimes or are sent to a mental health institute. \n\n",
"Why is the care system weak? Because it's not there to actually help people with mental illnesses. It exists because it's profitable. There's no other industry where you can literally force people to buy your services.\n\nI was put in the psych ward against my will for a week. They pretty much lock you in a room with a bed and nothing else, and you're for the most part completely deprived of human interaction, except the rare 5 minutes the doctor will come in and ask a few questions. I'll tell you, if you have depression, being isolated and having nothing to do doesn't help, and, if you have anxiety, being detained against your will, forced to neglect your responsibilities, and given no idea when you might get out doesn't help, either. But you have to try to convince them that you're happy in this horrible setting for them to consider letting you out. And then, when they think you're alright to leave, they force you to sign a paper that says you were there of your own free will, and they won't let you out unless you sign it. Then they send a bill for tens of thousands of dollars.\n\nThe first step we need to take to make mental health care better for the patients is to have some respect for them. It needs to be less like a prison. And we need to eliminate involuntary hospitalization because that's no different than kidnapping. Let people who suffer from mental illness live as normal of a life as possible. As long as they have not committed a crime, the mentally ill should have the same rights as any other person. No one else should get to determine what's in someone's best interest. \n\nWhy is there a stigma around mental illness? There's only two real possibilities for someone with mental illness, either they try to blend in as best they can, or they get shoved in a hospital. If they're blending in, people think it's not so serious because they don't know what's going on in their head. If they're in the hospital, it's easy to dismiss them as crazy and dangerous because that justifies locking them up. There's no middle ground. ",
"It's not a United States thing, it's a global thing. The attitude is no different to any other western nation. And with the US being the current global leader in medical innovation, the lack of research into mental health ends up stagnating the whole field and thus the whole world."
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4cype5 | where were the federal regulators in the years leading up to the financial crisis? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4cype5/eli5_where_were_the_federal_regulators_in_the/ | {
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"They just weren't there. Someone will come along with a better answer, but this is my understanding. \n\nObviously these agencies existed, but they just weren't doing anything. Nobody was was doing the necessary checks for mortgages and all that. It was just a \"Let it ride\" kind of mob mentality, and everything seemed to be going great. Everyone really was blindsided by the whole thing. It's not like the FDIC etc. Was just turning a blind eye; they truly failed to do their jobs so badly that they had no clue about the state of the situation. "
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3660om | i'm stoned and have to know immediately- why is bubble wrap made of plastic bubbles that pop, rather than non-poppable plastic? | I understand HOW they pop - i.e. it's a buildup of pressure that the plastic isn't strong enough to withstand, so it bursts. But why not make it un-poppable so it was reusable? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3660om/eli5_im_stoned_and_have_to_know_immediately_why/ | {
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"To make it unpopable you could remove the air inside them or make the material much more elastic. \n\nRemoving the air isn't really bubble wrap anymore and doesn't protect your stuff with. A cushion. \n\nMaking the plastic able to move enough to be unpopable would have the same effect. Weights on certain areas? The plastic expands and the air moves away from those areas or spreads out enough that there isn't much air there anymore anyways. Basically it would lessen the effectiveness, if not void it completely, of bubble wrap. Also, I would assume the cost to manufacture would be higher."
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9mucth | why do the numbers mean on an automatic gearbox? (ex. 4, 3, 2, 2l) | My Lexus GX470 has D, which is normal driving, but it also has 4, 3, 2, and 2L. Now some places I have looked say it for capping the RPMs, some say it’s for Engine-breaking, and some say it’s for if you want to have some fun with a manual-like experience without having to use a clutch. What do the numbers mean? Which should I use for different road conditions? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9mucth/eli5_why_do_the_numbers_mean_on_an_automatic/ | {
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"The numbers correspond to the gear. Automatic gearboxes have gears just like manual gearboxes. So slipping the gear shift from D to 4 would be down shifting (assuming you’re on the highway above say 50mph). Same thing for gears 2 and 3. If you try this, you’ll notice your engine will rev higher. If you take your foot off the gas, this is called engine braking - as it will lightly slow down the car. If you keep your foot on the gas, you’ll accelerate more quickly than if you had left It in D. \n\n2L is a step below 2nd gear and is used for decelerating steep grades at fairly low speeds. ",
"On all automatics I've ever driven, that's the highest gear the car will automatically shift into. Your car is (I think) a 5-speed automatic, so D means that when you start from a stop, it's in 1st gear, then it will automatically shift through all the gears up to 5th. If you put it in 4, it will only ever go up to 4th gear, 3 to 3rd, etc.\n\nThere are a few reasons you might want to do this. Ever wanted to pass a car, so you step on the accelerator and there's a bit of a delay before your engine revs and you get more power? That's because it takes time for your car to realize it should automatically downshift. You can instead shift to 4th or 3rd yourself just before you want to accelerate, and it will respond more quickly.\n\nOr if you're towing something, especially up a hill at low speeds, you may want to put it in 2 or 2L in order to get more torque.\n\nOr engine braking, as /u/Moron14 talked about.\n\nSide note: on some cars, the top gear is called \"Overdrive,\" because the second-to-highest gear has a gear ratio of 1:1, and the highest gear actually spins the wheels faster than the engine for better efficiency at highway speeds.",
"To expand on why you would use these lower gears. Say you are pulling a heavy load up an incline at low speed. Selecting 2 or 2 low will keep your transmission in a low gear that is more advantageous for towing. If you live in a place with bad winters you know the feeing of hitting the brakes and immediately starting the slide. Shifting down will help to slow the car without locking the wheels, keeping you in control. ",
"Each of those numbers represents a gear that you can manually select by shifting to that position.\n\nD is for normal driving in automatic mode. The car makes calculations based on how far the accelerator is depressed and RPMs, among a few other things. It automatically makes a decision based off of these calculations as to what gear it should be in, and shifts to that gear. This is why as you accelerate gradually, you hear the engine revs go up and then suddenly fall repeatedly. Each time the RPMs and speed hit a certain threshold, the car will shift to the next gear, and drop the engine speed to match the needed RPMs to match that gear's rotation speed. \n\n4 for 4th gear, 3 for 3rd gear, 2 for 2nd gear, and 2L for low 2nd gear.\n\nThis serves multiple purposes. \n\nOne purpose is that it essentially lets you have a \"clutchless manual\" experience. You are in relative control of what gear the vehicle is in (some vehicles will automatically start to downshift as you come to a stop. This depends on how they've set up the manual selection mode in the vehicle), but you don't have to worry about working the clutch pedal, the car does that work for you.\n\nAnother purpose is to provide you with enhanced acceleration. If you're experiencing a bit of hesitation in your shifts when you try to suddenly accelerate, you can override what the transmission is seeing and directly instruct it to shift into a specific gear (usually down 1 gear) in order to quickly surge forward.\n\nYet another purpose, and the one that I use this feature most frequently for, is for enhanced control in slippery conditions. When the vehicle is in a lower gear, more power is put into torque, rather than speed. So instead of the wheels spinning quickly, they'll give a slow, hard shove. This is particularly useful in snowy conditions where traction is low at higher speeds. By forcing the car to stay in low gear, you limit your speed to what that gear can achieve (wheel spin is less likely at lower speeds, thus giving you more traction), and you increase torque to the drive wheels, which helps give you a shove. This allows you to maintain more control over your vehicle. ",
"They're for restricting the transmission to lower gears, which you may want to do in situations where it may be beneficial to run the engine at higher RPMs for more torque rather than letting the transmission decide to shift. Such situations would include driving on very hilly terrain or pulling a trailer - situations where you want strength rather than speed."
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65xa06 | how did recording on wax cylinders in the early phonograph days work? | I can't seem to find a reliable source online that explains how someone at home, with a phonograph and a blank wax cylinder, was able to record themselves. I'm preparing for a brief presentation on the topic, and would like to be able to explain how this works in a simple way that makes sense to all.
| explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/65xa06/eli5how_did_recording_on_wax_cylinders_in_the/ | {
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"Recording on wax cylinders required a two needle machine, not the single needle player that most people had at home. The recording mechanism had a clockwork system to move the stylus along the cylinder in a long spiral. This could be played or used to make a master. To make a master, gold vapor was plated into the groves to make a reverse master. The brown wax cylinders people played were molded from this master."
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a4h2vx | what patterns am i supposed to hope for on slot machines? | I know from movies that seeing three 7's means "You're a winner!!!" But random patterns seem to give small returns randomly as well. Are there basic patterns across slot machines that signify a win? Or is it just madness and flashing lights. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/a4h2vx/eli5_what_patterns_am_i_supposed_to_hope_for_on/ | {
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"There are keys to winnings on slots nowadays. And if you play 2 or 3 coins at a time you can win on diagonal combinations.\n\nThe whole point is to be flashy and fun though. ",
"Each slot machine will have a different pattern of \"paylines\" and reels. Each individual game should tell you what the paylines are.\n\nGenerally, though, you're looking for at least three of the same symbol in a row, starting from the leftmost reel. Betting more coins generally gives you access to more paylines; betting one coin probably only pays if you hit three of the same symbol in the dead middle of the reel.\n\nEach symbol also has a value; some symbols are worth more than others. Hitting three or more of a higher-paying symbol gives correspondingly higher payouts."
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259ivf | why do we use the nielsen rating system, it seems like it wouldn't be very accurate | it just seems like its a flawed system i even found out that only about 20,000 people even have a nielsen box, that cant be an accurate representation of what 300 million people are watching | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/259ivf/eli5why_do_we_use_the_nielsen_rating_system_it/ | {
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"Statistics are weird like that. It seems like you would need to ask way more people, but you actually really don't. A general rule of thumb is that if you want to sample a population of size X, you only really need to ask sqrt(X) people to get an accurate result. The square root of 300 million is somewhere around 17 thousand, so 20 thousand people with Nielsen boxes is more than enough.\n\nWhy's that the case? Well, the math behind it is fairly sophisticated, unfortunately. Suffice to say that this is something that has both theoretical (ie mathematical) backing, and has also been verified by people who actually went through the trouble of asking an entire large population something and comparing it to their result when they only asked a small subset of the population. It turns out to just not matter how many people you ask after a certain point.\n\nAlso, there are 300 million Americans, but only about 100 million households or so. The Nielsen box records what everyone in the household is watching."
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bdrj8t | why is the notre dame so important? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bdrj8t/eli5_why_is_the_notre_dame_so_important/ | {
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"One of the most historically important cathedrals of the Christian world and an architecturally significant structure for Paris. The cathedral is considered to be one of the finest examples of French Gothic architecture. The cathedral is one of the most widely recognized symbols of the city of Paris and the French nation.",
"It has a great historical significance which made it a symbol of power, the place where you had to be crowned or buried to matter in France (and thus Europe when France was its most important country). It was for a long time the biggest cathedral and one of the biggest buildings in the western world.\n\nAnd it's a beautiful cathedral in the middle of one of the most visited cities in the world.\n\nSit in an island, it magnificently stands out and it's a building you often see when crossing the city. It makes it part of the mental representation of Paris in the mind of all who have lived here.",
"Historically, it was the first building (at least in western culture) to have reached an inside height of 100'+ when all the others were only 70-80'. That's a pretty significant difference when your talking 800 years ago. \n\nAlso, all streets in Paris radiated from it and it was considered to be the city centre, so if it was 100 miles to Paris, it was 100 miles to Notre Dame.\n\nSource: some architect discusing this topic on the news earlier so I could be wrong.",
"Dude, I can appreciate ELI5 posts, put just Google it. That's kind of like asking, \"ELI5- why is Neil Armstrong's moon landing considered noteworthy?\"",
"This is better in r/outoftheloop."
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3m7gtt | how does glock come up with the model numbers for their pistols? | Is there some kind of system behind it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3m7gtt/eli5_how_does_glock_come_up_with_the_model/ | {
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"Their first pistol was the Model 17, named because it was the company's 17th patent (Glock had patents for 16 non-pistol items prior to the model 17). I believe the rest are numbered in order of introduction (with the select fire 18 being unavailable for civilian sale and 25 and 28 not meeting US import laws (due to their size) so are skipped in the States). "
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cvr4ex | how do small landlocked countries have different languages? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cvr4ex/eli5_how_do_small_landlocked_countries_have/ | {
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"Historically, transport was terrible. If you lived between two mountain ranges, you likely spent your whole life without ever leaving your area.",
"Because there are plenty of geological barriers that would, historically, inhibit travel, such as mountains, rivers, oceans, vast swaths of desert. Even lacking something like that, most people throughout history simply didn't travel. You were born in a city/town/village, grew up there, and died their, without ever leaving or traveling to visit some other place.\n\nAll it takes for a language to diverge is relative isolation over time.",
"This is a very modern type change of languages being more unified.\n\nFor much of history, even people in the town next to you might not speak or same language or if they did, it may not really be mutually understandable between the two towns, it could be that different just a town away.\n\nTransport and travel were pretty rare, people almost never left within a very close area of where you were born and resided. This meant that there wasn't as much mixing as you see now and each town or area would often have their own language or dialect, and since interaction wasn't that common, they didn't really have more standardized stuff or a reason to need to understand others or coordinate on a mutual language.\n\nFor example, French that we know today wasn't even widely spoken in France until the 1800s, it was really just in Paris and some of the surrounding areas. The rest of the country spoke various, often not mutually intelligible versions of French or local variant languages, and even basque, italian and such. Yes it seems weird as an English speaker to think that only a small portion of France spoke french, but until reforms after the French revolution, which spread modern French (forcibly spread), the country certainly had nothing of the sort of a universal language/dialect and with especially if you lived in the south of france, where likely to speak a dialect of french that didn't extend past within a couple towns of your birth, and past that you were totally un-understandable to a modern french speaker"
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1vuuag | what is happening in a babies mouth when they are cutting teeth? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1vuuag/eli5_what_is_happening_in_a_babies_mouth_when/ | {
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"The teeth are pushing up through the gums. It's rather irritating to the baby, so they often will put things in their mouth in an attempt to alleviate the irritation."
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2b0hfg | i currently have a cold, and have a runny nose. why is it that when i snort really hard and my nasal cavity seems to get "tight" that i feel that release of air shortly after? | It's hard to describe but if any of you are scuba divers it's similar to equalizing your ears | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2b0hfg/eli5_i_currently_have_a_cold_and_have_a_runny/ | {
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"I know exactly what you're talking about, like your nose pressurises then slowly deflates. \n\nWaiting for a good answer :)"
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6weifs | what are hadley cells and what role, if any, do they play in atmospheric/weather changes? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6weifs/eli5_what_are_hadley_cells_and_what_role_if_any/ | {
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"They're large scale atmospheric circulations that go from the equator to the mid latitude areas for both the north and south hemispheres. They're what drive the weather in the tropics and subtropics. For example, they cause the trade winds that push tropical waves off of africa and into the atlantic, resulting in Cape Verde style hurricanes.\n"
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6a6er4 | why do university professors make tests impossibly hard and then curve the grades? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6a6er4/eli5_why_do_university_professors_make_tests/ | {
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"Doing that is the only way to differentiate between the top students. If the test is easy, and 5 people get 100%, then the professor has no way of knowing what advanced topics those students are struggling with. Be making the test difficult enough that *no one* gets 100%, it becomes possible to rank the top students in relation to each other, and help them discover what their weak points in the subject are.",
"There are two purposes for Tests. One is to know how well you have learned the material, the other is to find out what areas of the material the teacher need to focus more lessons on. \n\nFor most of high school the subject are only taught at a \"surface level\" and you really only ever see tests that measure the amount learned. As such you design the test to be completable at 100% if a student has a mastery of everything taught so far. \n\nCollege classes go much deeper into subjects. They get into the complexities of things such that no human is capable of actually mastering everything taught on the subject. So they tend to lean more heavily into testing to find out what areas of the material that they have covered need to be covered more or in a different manner to help the students understand. So if all the class only gets about 50% of the test right and they for the most part all fail the same parts then those parts need to be taught again. ",
" > Is there a reasoning behind this? \n \nYes there is. Simply put, if every student answers a question correctly, then you've wasted a bunch of their time but haven't really gained anything. The purpose of the test is to quantify how well the students understand the material. Hard questions are better diagnostic tools. Lets simplify it and say the person designing the test has three types of questions he can use: \n1) Questions he thinks everyone will answer correctly. Not super useful but a few let you identify the occasional student who completely fails to understand even the basics of the material. \n2) 'Hard' questions. Generally each of these will involve going into a single topic to some depth. These will identify if there are some concepts that the students sorta understand but don't quite grasp the details of. \n3) Ask some complex (or really hard) questions that you don't actually expect the students to answer. Often these involve interactions between different topics that you've covered that may not always be obvious. This allows you to identify the really exceptional students in the class. \nWhen I used to help design tests we would shoot for an even mix of these three kinds of questions (or more often our questions would have an 'easy' part, a 'hard' part and a 'complex' part). The end result of this was that 'passing' was generally 40-70%, above 70% signaled someone who was worth some special attention, and below 40% signaled someone who needed some serious help. If the average dipped below 50% then that was an indication that we might have screwed up somewhere in teaching the material. ",
"One of the things I've noticed is that while making tests extremely difficult has its uses, it's used way too often. Many times, it's professors that are brand new and straight out of industry who routinely write tests that are basically impossible.",
"As a math professor, I can give you an honest answer to this. When you study a subject for ten, twenty, thirty years you internalize a great deal of it. The basic things you're teaching undergraduates over and over come to seem *really easy*. This can lead to unrealistic expectations about what you can expect students to learn.\n\n(This is also the reason many professors aren't great at explaining their subject --- they forget that all the \"trivial\" things they now take for granted weren't obvious at first.)\n\nOn the other hand, you're going to take a lot of heat from the university administration if you fail everybody. So one easy way out is to make a test that you think is fair, but is actually really hard, and then grade it on a curve so enough students pass."
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29v26s | how do people train themselves to sleep with their eyes open? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/29v26s/eli5_how_do_people_train_themselves_to_sleep_with/ | {
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"[Like this]( _URL_0_ )"
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57k9a8 | why is it impossible to generate truly random numbers with a computer? what is the closest humans have come to a true rng? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/57k9a8/eli5_why_is_it_impossible_to_generate_truly/ | {
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"The issue stems from the fact that there is nothing random about your computer. Everything a computer does is simply arithmetic operations. So you want a mathematical function that can create a random number.\n\nOkay well, a function takes and input and gives you an output, with your output being your random number. But that would mean that your output is somehow related to your input. By that logic, if your output is truely random, then your input must be truly random. You can see we've arrived at the same problem, so we're out of luck in that department.\n\nSo we can't get a really random number because our computer can only do math, but we can get a pseudorandom number that kind of gives us a random number. There are a few ways of doing this, but a popular way is using the current time as your \"input\" value. Then your function takes that input, does some mathemagic, and spits out an output. How \"random\" your output ends up being is directly related to how good your function is.\n\nYou could have a function that takes today's date and outputs the current hour as your random digit. Obviously that's a terrible way of doing it. Perhaps your function can be summing all the numbers in the date, diving by 4, then adding 18 then dividing by 3, then rounding up to the nearest integer. That might get you something more useful, but you can still probably do better.\n\nOne of the best ways I've seen random numbers generated is by having an input value that comes from outside the machine. In this case, the input seed would be a measurement of the background static noise on a certain radio frequency as measured above the lab. This is a fairly decent way of ensuring you have a fair, random number.\n\nOf course there are other, and some definitely better, ways of generating numbers as I'm sure people will point out, but the gist is that you need an outside source of random info to give you that \"seed\" of randomness that you can grow into a usable value.",
"Software is always predictable, it always does what you tell it to. A software random number generator will go from one number to the next in a totally predictable order, a good random number generator takes so long to repeat that you can't figure out where it is in it's cycle.\n\nAs for a real random number generator, we have these, basically quantum noise is random by definition. The tick noises from a Geiger counter are random and proportional to radiation. People have connected these to computers to use but it's slow. For modern high speed random number generators they build multiple clocks with poor accuracy and heavily dependent on temperature. Temperature affects stuff in a truly random manner, this is exploited by making the clocks drift and then they are compared, the difference is converted into a number for use on the computer.\n\nThe latest Intel processor actually includes this in its design, if you have it and you're computer and you're using it then you get truly random numbers (hopefully, they haven't shown the design to us so we can't know if they did it right or if the NSA paid them to do it wrong).",
"A computer is primarily a machine that takes and input, does a calculation, and produces and output. This will never produce a random output, unless it has a random input.\n\nHowever, some of those inputs are slightly random, generally when people get involved. The time of day when you turn the computer on -- it's probably always around 9:00, but the exact second or millisecond is random. (In technical terms we talk about how many \"bits or entropy\" there are in the measurement.)\n\nWhen you move the mouse, the exact pixel it moves to is random. By collecting a lot of measurements with some randomness, it's possible for the calculation to combine them in a way that the output is truly random. Doing this requires correctly estimating how random different measurements are, so if the mouse moves because of a script written to automate the computer configuration then the estimate could be wrong. The clever part is that if the calculation is done right then adding non-random data doesn't hurt anything, so generally the computer collects a lot more entropy than it needs.\n\nIn Linux there is a part of the operating system that constantly collects these measurements so it can always produce truly random output. Of course once you've collected 100-200 bits of entropy, then you can use a pseudo random number generator for everything, since it's practically impossible to figure out what the input was or predict what the output will be. (In technical terms /dev/urandom is just as secure as /dev/random after it is properly initialized.)",
"Computers are designed to be deterministic. That means they will always do the same thing when given an instruction. Randomness is the exact opposite of this. Thus, the only 'true' sources of random data are external to a computer. \n\nCasinos, for example, have a CCD (charge-couple device; basically the sensor from your digital camera) in a heavily shielded box, and they poll that CCD for values several times a second. Cosmic radiation, bits of static, random other shit creates charges in parts of the CCD and not in others, and that 'noise' is the source of their random data. \n\nThere are methods for grabbing similar data from the CPU itself, but the attacks against those all boil down to the sentence \"If I can control all the other tasks the CPU is doing, then I can predict the random data...\" And that is true because, as I said, CPUs are designed to be deterministic.",
"Truly random means that there is no pattern or order what so ever to the numbers. Computers generate random numbers by using algorithms the problem with algorithms is that the spit out predictable results that follow a pattern. A basic RNG algorithm will use a pool of inputs to create outputs of random numbers. Say the algorithm takes in system time from OS and runs it through the algorithm and spits out a number. Thing is if you can repeat the seed you will get the same number out so not random.\n\n It's possible make a really fancy algorithm and use a fancy seed method that will sure as heck make it seem random to the average human and much less obvious to manipulate but the fact is that if you probe the inputs and outputs enough you will find a pattern eventually. \n\n The problem lies is algorithms themselves defined as \"a process or set of rules to be followed in calculations or other problem-solving operations\". As long as you are following \" a set of rules\" or steps to solve a problem guess what? It can't possibly be random. True randomness means no rules or set procedure and computers just can't do that. they only follow code programmed into by humans and have to use algorithms to do things like number generation.",
"In theoretical computer science, there is a concept called [Kolmogorov complexity](_URL_3_) that helps us define what it means for a string to be *random*. Basically, the Kolmogorov complexity of a string *s* is the *size of the smallest program required to produce s*.\n\nHere's an example:\n\n* String 1: \"abcabcabcabcabcabcabcabcabcabc\"\n* String 2: \"asdfgvcdertbvnmerticofhgtewqsx\"\n\nWhile both strings are 30 characters long, the first can be simply described as \"abc 10 times\", while there is no \"compact\" way to describe the second. Intuitively, string 2 is more random than string 1, because it's much easier to construct a set of instructions (aka a program) to generate String 1.\n\nThe only way that we could define a *truly random* string is to write down the string itself; if there were a (deterministic) program that could produce it for us, then the string is no longer truly random by definition. So if we'd like a \"random number generator\" program to generate random numbers on demand, it would have to be able to generate an infinite number of random numbers. And because the Kolmogorov complexity of this infinite string of numbers is as long as the string itself, the program would need to take up infinite space.\n\nIn real life, we use pseudo-random number generators, which take advantage of some amount of randomness or entropy from the program's surroundings, and often a user-specified \"seed\". But, given identical initial conditions, the program would produce identical output. So while the numbers are often \"random enough\" for our use, they are not truly random.\n\n[_URL_2_](_URL_0_) generates random numbers via atmospheric noise and has passed a number of statistical tests. You can read some of their analysis [here](_URL_0_analysis/).",
"There are random processes within your computer. You can measure the thermal noise in the resistors in your sound card for example. Then use that for your random number generation. It's called Johnson–Nyquist noise. All you would need is a sensitive voltmeter built into your computer and an ADC converter to generate random numbers all day long.",
"It is *not* impossible to generate truly random numbers with a computer.\n\nThere are microprocessors with an internal mechanism for generating entropy based on random manufacturing anomalies and unstable circuits. The point of it is that it is not externally examinable by any reasonable means, so it's not only a genuine source of random numbers, but it is secure. That is to say, if an isolated process running in your system fetches these entropy values no other process can know what those values were.\n\n[The latest processors from Intel and AMD have this technology](_URL_0_).",
"John Von Neumann, who developed a lot of the groundwork that led to computers, said:\n\n > \"Anyone attempting to generate random numbers by deterministic means is, of course, living in a state of sin.\"\n\nIf computers are reliable, they aren't random. For their behavior to be completely deterministic - for the program to do what you want it to do, and hopefully not do anything you don't want it to do - there needs to be clearly-defined steps to get from here to there. Figuring out how to do this led to the computer architectures we have today.\n\nSomewhere along the line people realized they needed random numbers for certain things, and people developed many ways of generating *pseudorandom* numbers: numbers that appear to be reasonably random, if you don't watch them too closely or for too long.\n\nPseudorandom number generators (PRNGs) are given a 'seed' number to get them started, then they do their thing to create a chain of hopefully-random-enough numbers... but if you know the seed, or can precompute many chains of values based on many different seeds, such generators stop being random. They are completely deterministic, so anyone who figures them out has complete knowledge of past and future values. A while back an online poker site published their randomizing code so people could see that the game wasn't rigged; someone fed a huge number of possible seed values into the site's PRNG, and from seeing what cards they got next they could narrow it down until they knew exactly what seed value was used, exactly what numbers were coming next, and therefore exactly what cards everyone else would be dealt.\n\nIf PNRGs are watched long enough to cycle through every step in the chain, they repeat the same numbers. This is called their 'periodicity', and in general more = better. The good news is that the period of a PNRG gets doubled for each bit added to the internal states they use to generate numbers. The bad news is that computers trying to crack open the PNRG (or data encrypted using the numbers generated by the PNRG) get faster all the time.\n\nTo get truly random numbers, something other than the completely deterministic output of a computer is needed. When generating a public/private key pair for encrypting and decrypting data, for example, many programs ask you to jiggle the mouse and hit random keys on the keyboard. Some of this data would be too deterministic, but if you take the time each event happened and throw away everything but the milliseconds (or everything but the last bit) the numbers jump all over the place.\n\nThere *are* electronic methods of generating truly random numbers. While computers depend on a bit being a 1 or a 0, the CCD of a digital camera needs to figure out how much light hit a specific location. Incoming photons smack electrons around, and electric charge is measured. But most electronics are sensitive to heat, because heat is (basically) jiggling electrons... not the best thing to have happen, in a device paying close attention to how many electrons are moving around. In practice, an extra electron here or one less electron there wont change a digital photo much, but if you sample the CCD when the camera is in the dark the *only* thing you see is the noise created by thermal excitation, and heat is truly random. As with mouse movements and keyboard hits, some of the data won't be particularly random - e.g. most of the CCD will be at the same temperature - but if you look at just the differences, the small amounts of thermal 'noise' are truly random.",
"Modern Intel processors, and likely others, DO have a truly nondeterministic random source. There is a (relatively) new instruction that lets you retrieve random numbers seeded from it.",
"A lot of good explanations here about the deterministic nature of computers and why they don't generate random numbers. I'm surprised about the little mention of quantum mechanics, though, which as far as we know is truly random.\n\nHeat flow and atmospheric noise can produce some very random data, but whether they are truly random is iffy and depends on what kind of thermal/atmospheric system you are look at.\n\nNothing beats quantum mechanics when it comes to random generation.",
"In short: you cannot do it in software. If you don't mind buying an extra piece of hardware that measures background noise or something quantum mechanical you can have true randomness",
"Not an answer to the question, but here's a really good explanation of the RNG in Super Mario 64. The function is well-defined and we know how it works, but for a person casually playing the game it looks totally random.\n\n_URL_0_",
"I just wanted to point out that _URL_0_ uses radio static as a source for true randomness, and they have all kinds of cool info and stats on why they are truly random. Great reading.",
"Computers, with well-written programs can produce excellent pseudorandom numbers, as tested by various statistical and cryptographic measures. Pseudorandomness is a critically useful property because it allows programs that are controlled by these numbers to run multiple times taking the same control paths, allowing programmers to locate bugs in such programs and carefully debug them.\n\nEspecially for security purposes, when truly random, non-reproducible random numbers are needed, measurements of unpredictable events, often referred to as \"entropy\" and including, for example, keyboard input timing, local temperature, speed of disc accesses, or bits sampled from high-speed ring oscillators, can be mixed into otherwise PR algorithms. This is often referred to as mixing in \"entropy.\"",
"Radioactive decay is random. Hook your computer to a Geiger counter and you can make a truly random sequence of numbers. ",
"Okay, people are dancing around the actual part of randomness, so let me address this with a little more clarity. The interesting part is at the end:\n\n\nComputers are designed to take an input and give a predictable output based on that input. By that idea, they are inherently non-random machines. However, we can write a program that takes an input number, and gives an output number that does not seem to be related to the input number. Essentially this means that to the human eye, we put in any non-random number and get a random number out.\n\nThe problem is that because it's a program, if you run enough times, a smart person can figure out how the program works, thus breaking the illusion of randomness. So how do we get around this? Simply, we find a non-predictable input, or a truly random input.\n\nNon-predictable inputs? This could be things like the 3th decimal of the current temperature inside your computer, or how many miliseconds past the hour it is. Because these numbers change so fast and so often, picking one at any time gives a number that is pretty close to random. \n\nActually random numbers? Well, particles like electrons are actually random. Not just unpredictable in a human sense, but actually random by nature. They can teleport short distances, exist in multiple places, exist in a location purely by probability. Basically, on the quantum mechanical level, they are truly random. And we can use that to make an input to the computer.\n\nHow do they do this? Well, one way that is actually in some of the latest processors works like this: Imagine you are tuning on a light switch. At the bottom it's off, and at the top it's on. But what happens in the middle? If you are in the bottom half, it's still off, and the top half, it's on. But when the switch is truly in the middle, the switch might start popping and the light will flicker as it figures out whether it's connected or not. Transistors in a computer work the same way as that switch. Too little electricity, and they are closed, more than that, and they are open. But, right in the middle, only one or two electrons make the difference between open and closed. Because these electrons are inherently random, the whole switch then becomes randomly open or closed based on their behavior. We can then sample this switch a couple times and build a binary number using open as a 1 and closed as a 0, and that gives us a usable number from a switch.\n\nSo, modern computers can use this actually random number, feed it into a program that changes it a bit, and then spits out a truly random number.",
"OP, I hope you're still reading responses. Many of the responses here are inaccurate or incorrect.\n\nThe answer to your question depends very much on how you define two terms: \"computer\" and \"random\".\n\nIf by computer, you mean a [Turing machine](_URL_1_), then the answer was sufficiently provided already. A Turing machine is, in essence, a machine that simply follows instructions and performs computations. Computer scientists like to think of real-world computers this way because they act this way for almost all intents and purposes. So the reason why no randomness can exist is because at every step, you know exactly what is going to happen next because the instructions are known. If everything is known and predictable, then nothing can be random.\n\nIf your definition of computer actually refers to real, physical computers that go into laptops and phones and such, the answer is different. You need to define randomness. u/mtgsrfer started with a pretty good definition of random, which is that an outcome is random if you have no way of determining how that outcome was generated.\n\nThis needs to be clarified, however, because when considering randomness, we also need to consider the *reproducibility* of the outcome. You may not know *how* a random number was generated (e.g. the algorithm), but if you can reproduce the outcome by setting up the same conditions, then the outcome really isn't random. For example, a coin toss is supposed to be random. But if you can set up a toss such that it was flipped the exact same way (maybe with a precise robot, for example), then the coin toss is not random. We often call numbers that *seem* random but are reproducible *pseudo-random* numbers. The main factor in being pseudo-random is if a sequence is *deterministic*, or can be predicted based on its input conditions. If you know the exact position and motion of a coin, as well as the environment its in (temperature, density, etc), it can be (almost) deterministic.\n\nThe measure of quality people use to when trying to generate random numbers is \"How predictable is a generated number compared to complete noise\", where noise is a number that cannot possibly be predicted no matter what the input conditions are or how much information is known about the system.\n\nPeople *have* found sources of randomness that are completely random and indistinguishable from noise. The two main sources are from [turbulence](_URL_3_) and [quantum noise](_URL_0_). Turbulence is the randomness associated with motion in a chaotic environment (think of rapids in a river or smoke coming from a fire). It is currently unknown if turbulence is predictable, even in theory. Even if it were predictable, the amount of information that you have to know about the system and the amount of computation required to predict it would be mindbogglingly massive. Therefore, it makes for a good source of randomness.\n\nQuantum noise, as far as we know, actually is completely random. There is currently no possible way to predict it, and science has not shown any hints that it might be predictable, either.\n\nGetting back to how this applies to computers, all standard Intel chips have a circuit built into them that can measure quantum noise. [Source](_URL_2_). I'm sure other companies at this point probably have similar offerings. So while this doesn't fit into the \"ideal\" definition of a computer because it isn't a Turing machine, real-word physical computers are capable of generating truly random numbers because they can directly measure random sources.\n\nI hope this helps!",
"You could probably make a real number generator by putting a bunch of numbered balls into a roller, shake it around to mix them up, then take them out one by one. ",
"I'm just going to leave this here...\n\n_URL_0_\n\nTo elaborate, this would be considered the \"closest\". It's basically based on a multitude of factors that could technically be predicted but the amount of work that would go in to syncing up with the milisecond randomness that something like this offers is well...\n\nYou'd be better off just rolling dice yourself and guessing in advance.",
"It isn't. Some [microcontrollers](_URL_0_) include true random number generators. \n\nBasically every electronic circuit contains a tiny amount of randomness in it. For the most part, computers are designed to shrink this randomness so they always give the same number 1 + 1 should always equal 2. A true random number flips this on its head -- it takes this tiny randomness and blows it up so every time the main part of the computer reads from the true random number generator, it gets a different number.",
"Several of the top responses in this thread seem to say that random numbers don't really exist even outside of computers, which isn't true. \n\nRadioactive decay is one example of a truly random process. If you have a radioactive sample of a given size there can be a 50% chance of it radiating an electron in a given interval of time. You can take 8 (or 16, or however many you want..) of these intervals of time and create a binary number from the decay events - 1 if there is a decay, 0 if not. There are even [websites](_URL_0_) where you can buy sequences of these 0s and 1s.\n\nThese numbers are truly random. The universe according to quantum physics (which describes things like radioactive decay very well) is *not* deterministic.",
"As to how close humans are to ever reaching true rng, we can use the radiation decay of an item (Think a Geiger counter ticking) as it is completely random and cannot be predicted. Unless you use something to see the atomic level and you can actually use the information there to predict the decay but that doesn't exist right now.",
"Technically you can't get anything truly random, a dice falls as it does because of physics and that makes it predictable (maybe not by us), not random. ",
"Theres one example I can think of where a company has built a number generator used by one of the worlds largest online poker websites _URL_1_. I have no idea if it's the best or closest thing to a random number generator, but it has been verified by the gaming commissions of multiple countries as well as independent labs. \n\nFor those who can't or don't want to watch the video it basically starts by explaining that a software generator is fundamentally not random and there needs to be hardware input to create truly random numbers. It works by shining a laser through a moving semi opaque mirror and every instant this is creating a stream of 1's and 0's by reading a reflection as a 1 and a pass through as a 0. Then it takes another stream of random numbers generated by the players mouse movements and the amount of time between their clicks. The video only gives a pretty non technical and laymen overview of how it works but still interesting and is a true attempt at making a random number consistently. From what they say they have dealt over a billion hands of poker using this method and from that data set they are able to see that the cards come out in a distribution one would expect statistically over the long haul. Although they have a huge financial interest in lying or not fully representing the truth of how truly random their system is so who knows for sure. But I would guess that if the system works as they say it does it's probably as close to random as one could expect to get within a reasonable budget.\n\n_URL_0_\n\nSo basically it seems the best way for a computer to create a random number is for it to take input from multiple uncontrollable sources that have no pattern. I would imagine true randomness isn't possible, but I'm way too dumb to explain or understand why.",
"/u/Bojodude already did a fantastic explanation so here's my eli5:\nComputers only compute aka calculate. The results of these calculations are always the same for the same input. If you want to add a random element to it, you need to get a random element elsewhere. Since it's really hard get a true random element as data into the computer, we usually just take non-static inputs from somewhere and allow it to be quirky with that.\nBasically when your computer does a random, it is about as random as a stereotypical 14 year old girl. Meaning it tries to be unpredictable, but if you look at the inputs and a little bit into her diary you can figure out why she had to put your razor in the microwave.",
"To put it simply, randomness is what cannot be predicted.\n\nBy definition, a computer program has inputs, and will always generate the same output, so it's predictable by design.\n\nComputers do have ways to generate truly random numbers, but it involves an external source of electrical noise, which cannot be practically predicted.\n\nPRNG (pseudo RNG) generates numbers but they require a seed (an unique number), and they will always generate the same list of pseudo random numbers each time.\n\n",
"What it really all breaks down to is that in a macroscopic, physical sense, can anything truly be random?\n\nFor example, think of the roll of a six sided die. Intuitive thinking tells you that after rolling it, the side you get is highly random, and equally likely as any other, right? You're as likely to roll a 6 as a 1, in theory, because it is a fair die, with perfect symmetry.\n\nBut once you consider that you need to mark each side by either adding paint, drilling out pits, or both, you realize that in reality, some sides can end up turning up more than others, and that's already less random.\n\nBut besides that fact, even an object with perfect symmetry with uniquely and immediately distinguishable sides can not only be predicted if you know all the starting variables, but can even be manipulated so that you get the result you want every time. This is true of any die, whether it be fair or unfair, due to limitations of the macroscopic, physical world.\n\nRandom Number Functions on computers are no different than dice. Both take input variables and act as a sequence of steps that result in an output value, and both can be predicted with enough study, and even manipulated.",
"There is a site that generates random numbers based on atmospheric pressure. Don't know how true since there weren't any sources on the article but I thought you might be interested.\n\n[_URL_1_](_URL_0_)",
"Technically we too can't generate truly random numbers, since any number we choose has a reason we chose it",
"Computers base their random generators on a current time seed, but if you know the algorithm and the current time, you would be able to compute it ahead of time. \n\nWhat is truly random in the universe? quantum level mechanics? In theory, if you know all the conditions and rules to a system, you can predict any 'random' outcomes. ",
"Real ELI5: you have to tell a computer how to generate the number. If you tell it how, it's not really random.\n\nThis of course isn't a perfect way to answer, but gets the point across. Programming instructions aren't random, neither are the physical foundations of the computer itself (generally) so it's not really random.",
"I can't believe the [lavaRnd](_URL_1_) isn't in the top comments! It still isn't truly random, but I'd say its the one of the most random and [interesting](_URL_0_) methods we have come up with! Here's an excerpt from the wikipedia: \n > \"Lavarand was a hardware random number generator designed by Silicon Graphics that worked by taking pictures of the patterns made by the floating material in lava lamps, extracting random data from the pictures, and using the result to seed a pseudorandom number generator.[1] Although the secondary part of the random number generation uses a pseudorandom number generator, the full process essentially qualifies as a \"true\" random number generator due to the random seed that is used. However, its applicability is limited by its low bandwidth.\" \n",
"Isn't radioactive decay considered, from what we understand about it right now, random? I could have sworn I read once that some computers will measure decay as an input source.",
"I know I'm very late to this topic, but it's something I have quite a bit of experience with. I'm a developer for [Roll20](_URL_1_) a VTT (virtual table top) to play tabletop games like Dungeons and Dragons online.\n\nPsudo-random numbers are probably random enough, but gamers are very picky about their dice. Roll20 implemented our [Quantum Roll](_URL_0_) system. As has been explained elsewhere the Quantum Roll takes a seed from a third party lab, that measures the fluctuation of a beam of light striking a particle, something that can't be predicted and uses that as the base for our calculations. \n\nYou can see the results [here](_URL_2_). Out of over a million rolls in the last hour, the average mean of a d20 roll is less than one one-thousandth of a percent off the perfect mean. Statistically speaking, the QuantumRoll is more random than the plastic molded and polished dice you buy from the game store."
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1jyzvq | i know some diseases take more than one shot, but many don't. why can't we clump all the vaccines we have a vaccine for into a single supershot? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1jyzvq/eli5_i_know_some_diseases_take_more_than_one_shot/ | {
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"Vaccines are like carefully cooked up dishes. Icecream sandwich and fries taste great individually but together they would probably suck. Likewise, when two vaccines mix they won't be as effective as they are individually.\n\nA vaccine is nothing but a sample of the organism that actually causes the disease in question (albeit on a very very low dosage). What a vaccine does is that it makes the immune system of our body get familiar with the disease and teaches it to fight it. The vaccine is the punching bag the immune system can practice on so that it can handle the real deal. \n\nTwo vaccines (which are again nothing but disease causing agents) might act against each other and render the complex substance ineffective hence defeating the whole purpose of the vaccine. Like the icecream sandwich spoiling the fries for you.\n",
"We can't give all vaccines at once because the immune response is somewhat cumulative in nature, meaning the more vaccines you give at one time the greater the spike in immune system response. This could cause your immune system to essentially make you sick by greatly overreacting. Given one or two at a time vaccines seldom cause the immune system to react to the point of being dangerous to the patient e.g. a prolonged high fever. "
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1ccfv6 | why did nobody attack vatican city and ww2? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1ccfv6/eli5_why_did_nobody_attack_vatican_city_and_ww2/ | {
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"Vatican City, to this day, is an independent nation \"of the church.\" It was neutral in WW2, as it has been for many conflicts.\n\nAlso, since Catholicism is so wide spread, any nation that went to war with Vatican City would have to deal with massive internal unrest.",
"Who would've wanted to? Which side? Why?"
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bl15b0 | do computers files weigh anything ? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bl15b0/eli5_do_computers_files_weigh_anything/ | {
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"Short answer: Digital files do not weigh anything.\nLong answer: storage devices have weight, and since they have a finite storage limit, more and larger files require more storage devices and therefore more weight, but the weight of storage devices is the same whether they contain data or not. Storing data does not add mass to the storage medium, it just changes the state of a tiny portion of the storage medium to represent the data, but the material that represents that state is already present in its entirety, it just exists in a state that reads 'empty'.",
"heyyy, always wanted to actually contribute to one of these!\n\nOk, imagine a checker board with one coin in each square. Flipping one coin to heads stores information, tails also stores information. But the board and the coins all exist already and weigh the same no matter what's stored. So no, the file doesn't have weight, but the physical thing the file lives on has a weight, BUT that weight isn't effected by what it happens to be storing."
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7x0a1g | what exactly sparked the culture of the stereotypical "wild west"? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7x0a1g/eli5_what_exactly_sparked_the_culture_of_the/ | {
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"It probably originated with *The Virginian*, a novel published in 1902 authored Owen Wister set in Wyoming.",
"Travelers were disappointed when traveling west and not seeing the old west. The town of Palisades, NV would stage gunfights and bank robberies for tourists during their train stop in the 1870s. The newspapers ran stories about the “dangerous” town.",
"More than anything else the stereotypical \"Wild West\" was popularized by the [Dime Westerns](_URL_0_) of the 1860s to the early 1900s. For example, Prentiss Ingraham, best known for his Buffalo Bill series, wrote as many as 600 novels by year 1900 and these sold wildly across the world. If one factor can be called the \"spark\" of the Wild West genre, it is the dime novel or dime western. "
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39u3p3 | do 'battery saver/extender' apps really work on mobile devices (phones/tablets)? | Does the rate at which a battery is charged affect performance? If so, why are these types of applications unavailable in the Apple ecosystem... | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/39u3p3/eli5_do_battery_saverextender_apps_really_work_on/ | {
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"Depends on the app and how it's designed to work. Remember that no app can increase the charge capacity of your battery, nor can it harvest energy to put into the battery. So usually these apps work on reducing CPU load and terminating background services. You may find them that they work well depends on how you use the phone.\n\nIf you are a gamer, I'm sorry to tell you that these apps will not change a lot how long your battery will last.\n\nOn the other hand if you are a regular user, you may find they extend the battery a bit. How much? It varies from phone to phone.\n\nEdit: spelling"
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7mp4xx | what is it about the chemical structure of gasoline, kerosine, and lighter fluid that makes them so instantly combustible? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7mp4xx/eli5_what_is_it_about_the_chemical_structure_of/ | {
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"They are hydrocarbon chain molecules. The hydrogen atoms are not very strongly bonded to the carbon atoms. As a result at a relatively low temperature the mixture can burn by regrouping with oxygen in the air to make H2O and CO2.",
"Imagine a rock teetering over a cliff. It has a lot of potential energy due to gravity. The rock wants to hit the ground, but the cliff is just barely holding it up. If you give it a tiny push, it will fall all the way down and smash into the ground. Then the rock would have the lowest potential energy and would be the most stable.\n\nThe fuels you mentioned work the same way. They have a ton of energy stored as carbon to hydrogen bonds. The carbon would rather partner with oxygen to make carbon dioxide. That would be the more stable form. Hydrogen wants to combine with oxygen to form water. That is it's more stable form. But they are loosely stuck together. If they get just a little push in the form of an input of energy from a mask, they will go directly to their most stable forms and release a ton of energy."
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6lzz1y | how will elon musk's battery fix south australias energy problem if it can only power 30k homes? | How will it force prices down as the premier claims? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6lzz1y/eli5_how_will_elon_musks_battery_fix_south/ | {
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"It won't 'fix' everything on it's own, it's when you combine it with all their other power stations it provides (in theory) enough extra power to make up for current shortfalls.\n\nIt needs to be noted also that it won't only be connected to just 30k houses, it will be spread over the grid. It provides the equivalent power for 30k homes, but this will be shared by everyone in SA.\n\nAnd it will do it (in theory) for a lot cheaper than the current methods (esp coal). The initial saving won't be much (maybe a few dollars on your bill) but what it means if it works is that when it comes time to build new power stations/replace old ones they have a better cheaper option available.\n\nLong term, this will mean more similar projects will be built, causing (again, in theory) prices to go down, because people will naturally want the cheapest option - as long as it works. \n\n"
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1ub02c | why do some people seem to be naturally nocturnal! | I've always felt more comfortable sleeping through the day than I have during the night. I often wake up at about 8pm and go to bed just before noon.
A few other people in my family have similar sleep patterns, but none of us are able to figure out why. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1ub02c/eli5_why_do_some_people_seem_to_be_naturally/ | {
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"Delayed Sleep Phase Syndrome. Its a pita to get an official diagnosis."
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25b85a | why is college education in the united states so focused on career acquisition/progression rather than the pursuit of knowledge? has it always been this way or is it a "recent" development? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/25b85a/eli5_why_is_college_education_in_the_united/ | {
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"This is written by Edsger Dijkstra : _URL_0_",
"I think your question is based on a somewhat false premise: there are many, many degree programs offered in the US that don't have an easily identifiable career path linked to them.",
"I'm sure there was a point in history, up to the early 20th Century, where higher education was mostly a way for the upper class to acquire a liberal arts education, learn how to be a gentleman, read Latin, etc. There was also a point up to the 50s or 60s where women mostly went to college in order to find a college-educated husband (\"get an Mrs degree.\")\n\nNow, college is widely available to the middle class, and women aren't expected to stay in the kitchen. The downside is that the people who go to college will need to work for a living. College is incredibly expensive, and it has been for a long time. It only makes financial sense to get a BS, MS, or PhD if you're rich enough to not care if it's useful, or if it helps you make enough money to pay off your student loans.",
"The cost of college education has increased exponentially and at a faster rate than inflation since around 1985. This has gotten worse within the past 6ish years: with the \"every child goes to college\" mentality of high school, the death of tracking students into trades and apprenticeships, the increase in standardized testing which lead to school's receiving better budgets for the students they send to college, the exponential increase in student loans which lead to the exponential increase in tuition and university administrative staff, the death of unskilled labor via automation and outsourced labor, and every actually available job requiring a diploma, and the death of on-the-job training.\n\nNo one's going to pay $70,000 to read Proust because Exxon doesn't give a shit you read Proust except you. I can self-enlighten myself for free, but if I'm going to drop that kind of money, I need to be employable.",
"Part of this stems from the price of education and convincing parents that it is worth the price. When they are writing those checks for thousands of dollars they want to believe that their kid is going to have a job when they are done. To answer your question though I'm not sure how much this is reality versus a marketing strategy to get parents to keep paying these crazy prices.",
"\" A well rounded individual is rarely societies sharpest tool\" \nOur society has placed a very strong emphasis on specialization. \nWhile we talk a good game of individuality, independence, and freedom, we are largely funneled into narrow utilitarian roles. \n ",
"College admission counselor here:\n\nThe big question we get most often is easily about JOBS. It's coming from the parents AND the students. This is a big shift from even ten years ago when it was about dreams and desires - now even 16-year-olds (juniors in hs) are looking at the decision with an extremely pragmatic eye. \n\nCollege is an enormous financial investment that will follow many students and families for years after graduation, so they want assurances that it's worth it. Every college has to have hard statistical data to back up career success and every college is creating career centers to help boost those numbers relative to their competitor institutions.\n\ntl;dr - Job placement percents are the new student-faculty ratio.",
"It's a personal reason, but for me, I wanted to be able to take my intelligence, hone it, add practical knowledge, and leverage the network of my school into a career that would support my family for the remainder of my life. My school determined that the value of those services was in the neighborhood of $20k/year. My employer determined that the value of my education and demonstrated ability was worth in the neighborhood of $100k/year. \n\nIf I simply wanted knowledge, I would just click through wikipedia articles. ",
"If anything, I think most US colleges aren't focused nearly enough on career development for graduates. They pretty much hand you a degree and say farewell. And you start making monthly payments for their troubles.",
"Colleges and universities started out mainly as finishing schools for gentlemen. The goal was to receive a classical education so that you would fit in with others of your social class. Technical universities started with the Ecole Polytechnique in Napoleonic France two hundred years ago. Today in the U.S. virtually the entire focus is on future earning potential. Students really don't care about using their college experience to better understand the world, study history, etc. \n\nI would say the major sea change came in the 1980s during the Reagan era, although other stages of this change came about earlier as well. The decline of industry in the U.S. after the 1960s meant that those who wanted an upper middle class salary had to seek an advanced degree in a business or technical field. \n\nBut the downside is that this has brought about a general change in public sentiment. Fewer people with college degrees have even an inkling about literature, history, cultural relativism, etc. As a human being, there's a lot to be gained from a liberal arts education, which is why universities still (much to students' chagrin) require them to have two semesters of U.S. history, etc., before they can graduate - regardless of their major. If the students had their way, they'd only take courses within their major, since they see all other subjects as useless. \n\nWitness the rise of philistinism. It's not pretty.",
"Its hard to justify soul crushing debt with out the justification of future success",
"I'm sure if college was free or cheap then there would be lots of people who would pursue degrees just for the knowledge. Since you have you to pay A LOT for a college education then people are trying to make sure the investment pays off.",
"Fifteen years ago, a lot of people sort of had the attitude of \"you can do anything! Get a degree in what you feel like getting!\" The attitude wasn't universal, other people said \"get a degree that pays well, because hard times are coming!\"\n\nRecently, people have realized that it's hard to make a living with a degree that doesn't translate directly to a career (in our current economy), so the first viewpoint has fallen out of favor.",
"I think that it used to be this way but has since changed because of the high cost of a college education. Everyone still wants knowledge and a college education, but now you have to pay off your loans. So you might as well kill two birds with one stone and go to college in order to get a career to pay off your loans. \n\nYou learn a lot more in college than just your major, and a college education is often all some employers want; they don't always require you to have a specific major. However, had I been not concerned at all about loans, I might have majored in paleontology instead of Mech Eng. I really like mech eng and I would love to have a career in it, but I've also loved dinosaurs as far back as I can remember. Currently, I am just content to make sure that I keep up with all of the latest dinosaur news.",
"A lot of people have pointed out that it has to do with the debt that is accumulated while going to college. A degree in the US is an investment towards a higher class. Now compare that to other countries that offer college for \"free\" (taxes instead of \"soul crushing debt\"). What type of affect does that have on a schools academic programs and an individuals choice for a degree? Would it still be about career progression/acquisition or the pursuit of knowledge? "
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7x6exg | why does water bother our eyes so much? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7x6exg/eli5_why_does_water_bother_our_eyes_so_much/ | {
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"This is dependent on the source obviously, but most water is not \"clean\", meaning it has particles of other things in it. Water in outdoor environments can have contaminants from farm runoff, dirt, algae, etc. Pool water can have chlorine, bromine, and salts that can cause irritation, and virtually all water, from taps, pools, bottles, the Atlantic ocean, you name it, has microbial life in it. The water isn't what usually bothers your eyes, it's all the microscopic bits of gunk in it that cause irritation by drying out the mucus membranes, stripping them, blocking the tear ducts, etc."
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5xok9g | what's to stop someone from broadcasting a radio frequency that is already taken by a local station? | For example: if a local top hits station uses 92.5 FM, what's to stop Joe-Shmo from broadcasting on the same frequency and disrupting the local stations radio? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5xok9g/eli5_whats_to_stop_someone_from_broadcasting_a/ | {
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"He will quickly be located and shut down by the FCC. Plus, he would need some powerful broadcasting equipment to disrupt the radio station over its whole area. That equipment is expensive to get and too big to hide.",
"Isn't there a malcom in the middle episode where hank tries doing that, and some government people chase him, because it's illegal",
"A raspberry pi single board computer can be programmed to brodcast FM across the entire frequency range used in America and I'm assuming the rest of the world too. It broadcasts with enough power and only using a 70cm single strand of copper wire as the antenna to over power any radio station for roughly 100 yards. The Pi costs $35, it's mindboggling. Crazy illegal, however if only done for a few minutes, the FCC probably won't have you in their crosshairs.",
"nothing other than laws. if you did it one time, nothing would stop you. the station would report it to the FCC and they'll log it. if you keep on doing it, FCC will send a team to track you down and when they catch you, they'll toss you in jail for it.",
"I assume that's why at night when your station turns into Mexican radio it's because they don't comply with FCC. I don't know why it seems to happen only at night either. Someone needs to ELI5. ",
"The law. And that's about it.\n\nBut you'd be surprised just how many legal hoops you have to jump through before the law is fine with you transmitting anything.",
"my high school electronics teacher was fond of answering similar questions with, \"but then they triangulate your signal and the big burly FCC guys show up at your door. \"\n\nMy buddy likes to broadcast his favorite music, pirate style, but he does it from a truck and gets away with it. probably not enough range to ruffle any government feathers, just a few confused commuters from time to time ..trying to figure out why Rush Limbaugh suddenly dropped the bass.",
"Legal consequences. There are some pretty hefty fines and criminal charges involved with doing this.",
"Nothing but the law, and the people who enforce it.\n\nBasically the same thing that keeps bad or stupid people from doing any particular thing that other people would find annoying.",
"That is \"pirate radio\". And nothing really stops someone from doing it, other than the fact that you'll get found and get in trouble with the FCC fairly quickly. Well, that and the initial cost of building a transmitter.",
"Amateur radio clubs sometimes have a contest called a \"fox hunt\" in which someone will set up a transmitter in a city (on a legally available frequency) and the rest of the club will try to locate it by tracking the signal. If amateurs can do it for weekend fun, a government law enforcement agency is gonna be more than capable.",
"Search for signal interruptions on youtube. There are some pretty well known signal hijackings that have taken place. ",
"Someone actually does this on a small scale on the interstate by our house. AM station randomly turns to Bluegrass for a very short distance. ",
"Now what's really interesting is if you did this on the 2.4ghz spectrum with a big enough transmitter you'd shutdown wireless networks citywide. \n\nThey'd probably also charge you with terrorism. ",
"So here is a true story. I was on a military exercise in nirthern california. I am electronics technician and responsible for the operation and maintenance of RF (radio frequency) equipment. We were operating in the VHF portuon of the spectrum and had a single channel plain text (unencrypted) net set up using 89.7 mhz as the transmission frequency. At one point our primary net went down due to equipment failure and switched to the 89.7 mhz frequency. After operating on thatvnet for about 4 hours a helicopter was circling our position and 3 federal agents in government vehicles arrived at the entry control point of our basebin the field. We were told that we were interfering with a public broadcast and needed to cease operations on thay frequency immediately. ",
"There is an old Christian Slater movie called [Pump Up The Volume](_URL_0_) that explores this very topic. Can't say it's super accurate, but I remember it being a decent 80's \"Teen Angst\" type movie..",
"Physically, nothing. Nothing at all.\n\nThat said, there are people who will be upset by it, and will track it down and turn it in. That then leads to five-digit fines and potentially jail time.\n\n",
"Triangulating and finding the source is fast. Once they have the equipment in place, they'll do it in minutes. Remember, the military does stuff like that all the time, so the technology is well known.\n\nThe same goes, by the way, if you set up an unauthorised cell phone repeater to boost reception at your home. Know a guy who, within a day, had people knocking on his door, asking him to shut it down. He quickly did, apologized and was lucky it ended there.",
"I once built a portable FM transmitter that runs off of a portable battery used to charge cellular devices. The range was about 100ft. The transmitter could broadcast on the entire FM and AM band, meaning I could set it to any popular station and everyone within 100ft would hear what I was broadcasting if they were on that particular frequency. As long as I'm moving I.e in a car, they will have difficulties tracking since they use the tri-locate method described in the comment section. \n\nP.S I made it as a prank to mess with a friend who loves alternative music, or rather, hates popular music. I put magnets on it and attached it underneath his car for a week. I made it play pop music on all of his favorite alternative stations. "
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4a7s5w | why can't doctors simply cut blood clots out of blood vessels before they reach vital organs? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4a7s5w/eli5_why_cant_doctors_simply_cut_blood_clots_out/ | {
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"A) blood flows quickly in larger blood vessels, 40cm/seconds in major arteries like the aorta, 15cm/sec vena cavae, so its hard to catch a clot\n\nB) every time you open a blood vessel, you risk rapturing it, also you have to clamp it, the larger ones have to be bypassed or you risk starving the brain or vital organs of oxygen and cause major damage and the blood pressure would make it impossible to work on, An Aortan dissection (when your aorta bursts due to a defect or injury) basicaly leaves you dead in a couple of minutes if they dont infuse you with fresh blood and crack you open immidiatly to patch it.\n\nIts just much easier and safer to use medication (blood thinners) or even smaller tools like a thin needle with a ballon over and inflate it to clear up a blockage then you actually dissect a blood vessel and destroy it. "
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8iyogv | lotteries, who funds them? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8iyogv/eli5_lotteries_who_funds_them/ | {
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"They're funded by ticket sales. If they give away $2 million in prizes, it's because people bought $3 million worth of tickets. ",
"The players find them. You pay to play and be amounts paid out are less than what is collected. Plus payouts are usually structured over a long time so the payer holds the cash during that time as well. "
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45xkkr | why does google release different features for their android and ios apps? | Google maps is a good example. It has "your timeline" feature that iphones dont. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/45xkkr/eli5_why_does_google_release_different_features/ | {
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"One reason may be that Mac has very specific style guidelines for its apps, to make everything look seamless and iPhone-like. Another reason might be that they simple have not implemented the feature yet as you often have to rewrite an app basically from scratch to make port it to another platform. Maybe they just thought that iPhone users and Android users want different features and styles. It might partially just be that there are different defaults and you can enable/disable some of the features in the settings."
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3pric3 | what is pump and dump scam? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3pric3/eli5_what_is_pump_and_dump_scam/ | {
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"Do you remember back early in this century, half the spam you recieved was stock \"tips\".\n\nThe objective of those emails was to get people to buy into a stock to rise it's price (pump) and then the spammers could sell the stock the bought before sending the email at a profit (dump).\n\ntl;dr artificially inflating stocks so you can sell at a profit.",
"There exists in this world a candy company. Let's call it Bob's Candies, Inc. They are a publicly traded company where stocks can be purchased by everyone. However, right now, the stocks are very very cheap because Bob's Candies, Inc. is a brand new candy company.\n\nYou decide you want to get a lot of money so you can spend it on things you enjoy. \n\nYou and your friends buy a whole bunch of Bob's Candies stock at $1 each. As much as you possibly can afford. \n\nThen you get a room full of telephones. You call as many people as you possibly can and you tell them the good news. \"Bob's Candies stock is trending upwards, you should buy some,\" you tell them. You don't tell them, however, that the upwards trend is because you and your friends bought a bunch of it. \n\nYou convince a bunch of people, hundreds, maybe even thousands of people to buy Bob's Candy stocks over the phone. Now your pile of $1 stocks is worth $10-a-piece because of how many people you convinced to buy it over the phone. \n\nYou then turn around and sell off your stocks at $10 a piece and make a profit. \n\nAnd with that profit, I assume, you buy some candy. "
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2dc2l9 | why is getting custody of children so complicated? | An expert would be nice, but I am just curious | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2dc2l9/eli5_why_is_getting_custody_of_children_so/ | {
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"Well in order for you to get custody, the other parent has to lose custody. You need to prove to a court that the other parent is so incapable of caring for the child that they shouldn't be given any time alone with it.",
"Because they are priceless, living people. If a parent who isn't fit to parent gets joint or sole custody, something can happen to them. It's a very touchy situation. \n\nI got sole custody of my daughter, and it was an annoying process. The thing is that the other parent can always petition to get an order modified (New York). So while she sits on welfare and pregnant with another man's child, I would have to take a day off from work to go out to court. The mother sees my daughter once a month, and doesn't even fulfill that amount usually. Children need consistency, especially when it comes to caretakers.\n\nSorry, went off on a rant. Family Court blows."
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2gglte | college football divisions/conferences. | SEC, PAC-12, Mountain West, Big 10... what are the differences? How are they formed? What are their reputations? Basically, if I'm trying to get into college football, which ones should I know, and what should I know about them? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2gglte/eli5college_football_divisionsconferences/ | {
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"First, let's discuss the divisions. \n\nCurrently there is Division I, II, and III for the major divisions. They are divided mostly by the number of scholarships they can award to players, which is based on factors like enrollment and funding. So Division I can award the most--85 scholarships on the roster at any given time. \n\nDiverging a bit here--scholarships are important. Most prospective players are not wealthy enough to go to play for a school and pay for it as well. Thus the very best players get the scholarships and the rest are allowed to \"walk on\" eg pay to play. Div I is allowed to award the most scholarships, thus its teams are the most talented. \n\nSo! Back to the ELI5. Division I (which we will focus on) is divided into two halves: FBS and FCS. These were formerly referred to as Division IA and IAA, respectively. They now mean Football Bowl Subdivision (the top half, which plays in bowls in its postseason but also starting this year has a small playoff) and Football Championship Subdivision (which straight up plays a playoff to end its season). As I explained above, the division is caused by the number of scholarships available. \n\nFBS itself is divided into halves as well, but this is more colloquial. The bottom half is referred to as the \"mid-majors\" or more recently, the \"Group of Five\" or G5. These are the Sun Belt, the Mid-American, Conference USA, Mountain West, and the American Athletic (not to be confused with the ACC--this was formed over the corpse of the now-defunct Big East). The mid-majors are not considered \"big time\" like the top half and are often subject to negative bias when it comes to ranking. While they get the same number of scholarships like the big boys, they often get the \"leftovers\" as they lack the large fanbases and tradition. However, parity has been increasing lately, and the best mid majors are often better than the worst-performing P5 teams; occasionally they can rise and challenge the best of them for everything (see: Boise State in the previous decade). \n\nThe top half of FBS was previously referred to as \"BCS Conferences\" or Automatic Qualifiers (AQs). These conferences are now the Big Ten, the Big Twelve, the Pac Twelve, the ACC, and the SEC. The Big East was a part of these conferences, but it became unstable after the transferral of Miami and Virginia Tech to the ACC, and it got raided for teams. The remainder dissolved the BE and formed the AAC (see above) but their status as a premier conference disappeared. Anyway, these are now called the \"Power Five\" or P5 conferences. They're the NFL factories. They have the largest enrollments, most funding, and have traditionally put out the most NFL prospects. Some of these programs, however, are really bad--teams like Purdue (Big Ten), Colorado (PAC Twelve) and Arkansas (SEC) are worse off than programs like Boise State or Nevada. \n\nThe best of P5 are often referred to the \"bluebloods.\" There are only a dozen or so, and they're the powerhouse programs, able to market their long and deep tradition of winning championships and putting players in the NFL. While some of them have had down periods, their tradition and support base is so deep they can often weather them and resume their dominance. Teams like Ohio State, Michigan, Penn State, Alabama, Texas, Oklahoma, Southern California and Notre Dame (plus a few others) reside at this lofty perch. These are the perennial contenders for the crown--which will for the first time be decided by a four team playoff at the end of this season."
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3d9x5h | how do personality tests know if people are lying? | This is honestly one thing I do a lot. You have to take some online personality test when applying for jobs, and you of course give the "correct" answers, that you know they want to hear.
How do these tests, or the people interpreting them, know if you're full of shit? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3d9x5h/eli5_how_do_personality_tests_know_if_people_are/ | {
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"One way they detect lying is by asking the same question in different words several times and seeing if you give the same answer. For example \"Do you usually find yourself the life of the party?\" \"Are you extroverted?\" \"Do you prefer the company of others to being alone?\" Depending on the test, the recruiter may also compare it to your resume or whatever else they know about you.\n\nBut if you're consistent and the graders don't have anything else to go on, they have no way of knowing whether you're lying or not.",
"Many personality tests have a \"lie scale\" that attempts to track the respondents honesty. Tests like these often ask similar questions multiple times to track if you give a consistent response. ",
"It depends on the rigor of the test.\n\nThe [Minnesota Multiphasic Personality Inventory](_URL_0_) is the gold standard \"personality test.\" Depending on the version, it has anywhere from 300-600 true/false questions specifically designed to get accurate responses. It asked the same question multiple times in various wordings to tell if you are being truthful. \n\nThe results of the test actually have confidence intervals for each personality trait; it assesses how accurate (i.e. truthful) the answers are. While you may be able to fool a few questions by actively lying, its tough to keep that up on a 600 question test _designed_ to prevent you from doing that."
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awcv67 | in a nuclear bomb detonation, how long does the fission/fusion last? what causes and makes up the mushroom cloud? | To clarify the second part, what *is* the mushroom cloud? I think it has to do with air pressures, but what is the cause of it in the first place? Does the fission occur in it as well, or is it just a mass of heat from the fission? Why is it still "on fire" for a while after the bomb drops? Is there actually fire (fuel + oxygen mix) inside of it?
Sorry for all the questions, I just watched a documentary on nukes, and have so many questions.
Thanks for the help! | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/awcv67/eli5_in_a_nuclear_bomb_detonation_how_long_does/ | {
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"The fusion/fission itself takes a fraction of a second generally.\n\nThis itself does not produce an explosion. It just releases a lot of energy in the form of heat and light\n\nIn physics/chemistry you may have learned that hot things expand and cool things contract. In practice, this is exactly what happens here. The matter in the bomb and much of the surrounding matter is heated so incredibly quickly that it expands so quickly, generating an exploding shockwave.\n\nIn a fire, it isn't the chemical flame reaction that causes the flame to glow. It is simply the heat. No matter the source of heat, heat up air enough and it will glow. This principle does not change with atomic bombs.\n\nAfterwards, once the explosion has expanded generally as much as it can, this hot air will rise up in a general column shape, mainly because it is less dense than normal air. However, the higher you go in the atmosphere, the less the pressure becomes. At this point the hot air just kinda expands in all directions, creating the \"head of the mushroom.\"",
"The fission and fusion reactions last on the order of a microsecond or so. All that energy is released, and the bomb destroys itself in the process, stopping the reaction. So the cloud does not contain fission reactions to any great degree (not on the order of those that produced it, anyway).\n\nWhere the bomb device once was is now a blob of superheated air, basically. Think of it as an exceptionally hot \"bubble\" in a colder and thicker atmosphere. It dumps a LOT of heat and radiation into the air around it, which creates the blast wave and other effects. But that blob maintains a lot of its gases and material (remnants of the bomb) and starts to rise (like a hot-air balloon). As it rises, it will churn around and suck in other dirt and smoke into it — this forms the \"stem\" of the cloud, if it's close enough to the ground to pull things in. As it rises, it flattens out (\"pancakes\"), which gives it the mushroom appearance. This basic appearance is common anytime you have one fluid moving through a fluid of a different density — it is called Rayleigh–Taylor instability.\n\nAnyway. After that microsecond or so, it's not undergoing a chemical reaction or a nuclear chain reaction, no. But it is very hot, _both_ from the remnants of the gases left over after the bomb goes off, _and_ because it's full of fission products, the half-atoms left over when you split uranium or plutonium. These half-atoms are _very_ radioactive, and that means that the cloud itself is super hot just from the radioactivity alone. \n\nIt starts to cool rather quickly, which is why it changes from the fireball (which is giving off lots of light) to a dusty cloud that, at best, is \"glowing\" with ionizing radioactivity (all sorts of interesting colors — reds and purples mostly — were often reported).",
"The actual fission/fusion only happens for an extremely brief period of time. It needs such high pressures that the triggering explosive has to be very carefully designed. In fact, fusion bombs have a conventional explosive that sets off a fission explosive, which *then* sets off the fusion.\n\nThe explosion creates an expanding sphere of super-heated matter. Once the initial fireball is over, there is a region of extremely hot smoky air, which starts to rise. That creates the stem of the mushroom cloud.\n\nAs the mass rises, air rises in the center, moves out to the sides, and gets sucked in again, which creates the top of the mushroom. This is similar to how blowing smoke rings works, except on a massive scale, and vertically.\n\nThe light you can see from the mushroom cloud is dust and air that is still glowing from the heat. Any combustion is long over."
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3daujb | why do so many european countrys have such a small military? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3daujb/eli5_why_do_so_many_european_countrys_have_such_a/ | {
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"Mostly because after WWII the US formed NATO which allowed those European countries to be secure under the umbrella of the American military with only a minimal contribution from their own domestic military. Basically, NATO spread the responsibility for collective security in Europe around to be shared by the various countries. \n\nAlso, with the European Union and the opening of borders across the continent, militaries and their associated costs have gone out of fashion in many European governments and most now spend very little."
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4phfdg | how are the olympics still going forward with all the issues they're facing? is an almost certain outbreak of zika not enough to put a halt to them? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4phfdg/eli5_how_are_the_olympics_still_going_forward/ | {
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"There's too much money at stake for the event to be cancelled or even delayed. You have people who have bought tickets in advanced and already set up travel plans which are not easy to change if at all. You have nation wide event plans which are date specific which were drawn up probably well over a year ago. You also have Brazil who spent a good deal of money to host the Olympics in the first place. Not to mention the potential hundreds of millions of dollars in bribes. \n\nAt this point the men and women in control are not willing to prioritize the lives of people over the financial chaos that would erupt if they chose to even hold off the event. ",
"\nZIka is not a huge problem as an adult, unless you're pregnant\n\nThe Olympics will also be during the winter, mosquito activity is reduced\n\n",
"Although there are many big problems with the Rio Olympics (corruption, crime, human rights abuses etc.), Zika isn't that big an issue. Firstly the games are taking place outside of mosquito season, secondly Rio hasn't been a hotspot of infections (the most affected area is the north-east of the country) and thirdly there's going to be lots of mosquito control efforts around games venues. \n\nThe World Health Organisation and others have examined the issue and all agree that influenza will be a much larger public health risk than Zika (and the flu is typically the biggest public health risk at any games). Some researchers have modelled the Zika risk and amongst all the games related travellers there might be only one or two Zika infections."
]
} | [] | [] | [
[],
[],
[]
] |
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