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63ktg1 | Why is internet in Australia crap ? | Repost | explainlikeimfive | {
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"It's a large continent with a small population, and it's very isolated from the rest of the world. That means you have to lay a ton of undersea cables connecting Australia to Europe, Asia, and the USA, while not having many people to fund it. In addition there has been political back-and-forth on it leading to issues. Basically, one major party argues that high-speed future-proof fiber should be partly publicly funded because it's going to be crucial fundamental infrastructure (like the road and water systems) in the future and Australia doesn't have the population and population density for it to work by market forces. The other party disagrees, sometimes for controversial reasons like considering the internet an entertainment medium or having a much lower definition of acceptable speed. As power shifts between the parties, the level and future of internet infrastructure changes. It is worth noting that Australian internet access is generally improving at a rate better than in the Americas. Australia has traditionally had universal transfer caps, and in the last few years they've started disappearing; the USA and Canada have traditionally not had them, but in the last few years they've started appearing. And for the same price in the same house, I have gone from 1.3 Mbps to 22 Mbps to 94 Mbps over the last 5 years.",
"95% of the English language internet is located off the island. This means they need transoceanic cables to connect to the rest of the world. It's a long distance, there's a small population & there not any other major developed countries nearby so there's not a lot of money in laying new cables. Since there's shitty connectivity to the outside world, the whole island is stuck sharing some undersized connections. This is on top of the problems that low population density causes with laying broadband lines on land."
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63m51t | If wage gap exists between the sexes, why can't businesses hire more women as a way of saving money on salaries? | Repost | explainlikeimfive | {
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"> If wage gap exists between the sexes It doesn't. The \"70 cents to the dollar\" stat that people throw around doesn't take into account things like hours worked, years of experience, etc. When you control for these things, the gap closes to 98 cents to the dollar. The slight difference here is believed to be differences in how aggressive men and women are when negotiating salaries and raises.",
"They could seek out women, but it is illegal to pay someone more or less based solely on their sex, age, etc. That said, the wage gap doesn't really exist in the way that it is often portrayed. Generally speaking there is little to no wage gap for the same work in the same field/position. The wage gap is simply taking all income of full time earners of men vs women in the country and comparing them. This \"gap\" of all overall earned income between the sexes doesn't take into account actual hours worked, education level, position, fields they elect to go into, etc. Women as a whole tend to work less hours, in jobs that are less stressful/dangerous, have more flexibility with hours and choose to go into fields that are generally less paying than men. This among many other similar factors is what contributes to the vast majority of the wage gap. There's a lot of propaganda and misleading information in the news/media that try to make people believe otherwise, but it goes against all facts and data. It's more of a politically correct argument than a sound/rational one. The truth is that women are more likely to get a degree and in nearly all metropolitan areas of the US single, childless women earn more than men. As these trends continue in favor of women, young men have begun to speak out and advancing the myth of the wage gap is slowly becoming less politically correct as the current generation of workers enter the job market and find that men are actually less \"privileged\" than women in many regards. The \"wage gap\" is largely a product of life choices that women and families make for themselves and not something that can be explained squarely as a product of bias in the workplace.",
"The wage gap isn't real. Not in that sense. The only way women make less is if you look at every profession of both sexes and average out incomes. The reason the gap comes up is that men tend to take higher paying jobs like doctors and construction workers. As where women tend to take jobs like nurses and teachers which pay much less. There's exceptions but that's really the only way it works out to a gap.",
"It's just a myth to get more Democrats outraged by inequality even when there isn't inequality. That's one of the ways the left tricks young sensitive people to vote for their party.",
"First: supply and demand. If the demand for women increases, then that drives up competition and increases salaries. Second: a wage gap exists between entry level employees and C-level employees, so why don't business replace all their C-level employees with entry level employees?",
"It is illegal to discriminate in pay between genders. The difference in wages between men and women comes down to differences in the types of jobs men and women take and differences in tenure. Women are paid the same for the same work as men. Women do not tend to have the same sort of education, participate in the same industries, or stay in their positions for the same periods of time as men do on average. What this means for the employers is that even if they look for people to fill particular roles and are completely blind to gender, there will still be differences in the average pay of women vs men."
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63mwrw | The "sovereign man" movement, wherein people act like they not subject to the laws of the land. How does this work? | Repost | explainlikeimfive | {
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"Lawyer here. > How does this work? It doesn't. The Sovereign Citizen/Freeman-on-the-Land/Moorish movement is a complete and utter fabrication devoid of any legal substance or intellectual rigor. Not terribly long ago, con artists began giving seminars and selling literature that ultimately formed these movements. Their ideas are based on very tortured and supremely technical interpretations of ancient laws, which, when mixed with a lot of mumbo jumbo and logical witchcraft, result in academic-sounding nonsense. But this nonsense is appealing to some people because it offers them a (supposed) solution to their problems, so they buy into it even though they don't understand it. They _want_ to believe they can trade in their birth certificate for a huge stack of cash. They _want_ to believe they don't have to pay child support because the flag in the courtroom has gold trim. And so they do. They watch the youtube videos and pay for the seminars and buy the literature. They file arcane and bizarre \"legal\" documents with all sorts of colorful text and stamps because it gives them a greater sense of purpose than just hiring a lawyer (to say nothing of the fact that it's far cheaper, and probably at least a little bit more fun). For a while, courts struggled with what to do with these kinds of people. Judges everywhere tend to take it easy on *pro se* parties (individuals without attorneys). Most often, they simply cannot afford a lawyer, and judges don't want to dispose of meritorious cases just because one party is broke. So early on, the judicial response was slow and tempered. But as the movement grew, so did the burden on the judicial system. Judges get pretty tired of defendants who won't identify themselves in court, who refuse to enter pleas, who interrupt the proceedings to spout nonsense, who make their clerks process nonsensical documents, etc. Now there's something of a playbook forming to dispose of these types of claims. There's a Canadian case called _Meads v. Meads_ (google it), where the judge is faced with a litigant like this. He goes the extra mile in researching the Sov Citizen movemen, dissecting their \"legal\" arguments, and discussing why they don't hold water. I think the movement has produced some newer flavors of insanity since _Meads,_ but it's still a pretty comprehensive overview.",
"It doesn't work. People get so wrapped up in their own philosophical interpretation of the law that they forget that law is ultimately about who has the power to enforce their views.",
"It doesn't work. They make dramatic leaps of logic to create a poorly conceived view of \"how law works\" and then lose in court.",
"It \"works\" in that someone believes crazy people with stupid ideas about how the law works and then simply declare that the law doesn't apply to them. Law enforcement however disagrees and applies the law to them regardless of their views on the subject, and people generally point and laugh at their idiocy."
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63pd76 | If human body temperature is 37 C (99 F), why is it when it's the same temperature out we feel incredible discomfort? | Repost | explainlikeimfive | {
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"We generate heat, and then lose it. When it's closer to 70 degrees, its a good balances of generating heat and then cooling down. When its 99 degrees out, we are generating heat, and then still heating. Basically, when it's cooler out our body can generate enough heat to keep us comfortable. When it's hot out, the heat we create is just in addition to it being already hot. Thats the general idea."
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63q08n | Why aren't taxes just done automatically? | Repost | explainlikeimfive | {
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"Planet Money on NPR had an episode about this a little while ago. A big reason is that tax preparing (H & R Block, TurboTax, etc) is a huge industry that employs a lot of people, and they've been able to leverage that into political power to keep taxes complicated.",
"We have a pay as you earn system in the U.K. It's your employers job to get your tax right so all a person needs to do is double check that they're in the right tax code when they start work. We get sent a document each year called a P60 which is a statement of tax paid. [PAYE]( URL_0 )",
"It could be possible for the IRS to provide a pre-filled form using the information they have, but that may be discouraged by the tax preparation companies. And for the majority of filers, they have numerous free options for filing out federal returns, although they require manual entry of many forms. However, for some people, there is a lot of paperwork involved. (I'm 21 and my return was over 12 pages long, and I could not use the 1040A or 1040ez forms). For those living without complicated situations, the IRS has a one-page simplified 1040ez that can be filled out in minutes."
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63qqd0 | Why if you throw, for example, a spider from a tall height, chances are it will survive with no injuries, but if a human is thrown from the equivalent height, we'd be badly injured/die? | Repost | explainlikeimfive | {
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"Spiders aren't heavy enough for them to be greatly damaged by a fall, plus their skeletons are outside, so it acts like armor. Humans are heavy, and our skeleton is inside, for support rather than protection (skull, spine, and ribs notwithstanding)."
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63u4la | What is offensive about the Kendall Jenner Pepsi Commercial? | Repost | explainlikeimfive | {
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"Reducing the complex and nuanced issue of police tensions with protesters to an oversimplified use of the platitude \"cant we all just get along, man?\". Shitty sugary sodas won't solve widespread issues.",
"\"Police are systematically targeting, killing, or imprisoning in a forced labor system the black youth of America. We demand justice!\" \"Have a soda, you will feel better.\" \"Oh, well it's all good, man.\" That doesn't seem maybe a little offensive?",
"Besides what other comments have said, it's opportunistic as fuck. Capitalizing on what is a huge social issue like this is in poor taste. Expect Pepsi to make some huge donation or start a foundation very soon.",
"Pepsi claims to care about social justice but in reality it is just trying to sell drinks. The ad is superficial and disingenuous, and quite obviously so. The use of a Kardashian family member does not add credibility."
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63v8ij | How exactly does radiation kill you? Slowly and instantly? | Repost | explainlikeimfive | {
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"Radiation kills off cells. The type of radiation and the exposure dose determines how death occurs. Extremely high doses can be instantly fatal while lethal high doses can do things like kill off the cells of your GI tract and prevent the body from taking up nutrients. Other forms can cause cancers or other diseases that have various lengths of time before being fatal. Mostly, its unpleasant.",
"It depends on the degree of exposure. It can damage the structure of cells, and also DNA. If the structure of a cell is damaged, it can kill cells outright. If the DNA is damaged, it can be in such a way that the cell divides problematically and does not 'terminate' as desired, resulting in cancer. How you die depends on what is damaged, to what degree that is damaged, and what form the damage takes. If your GI tract is ruined, versus if you get cancer in your GI tract, as an example. A low dose exposure may not cause you any noticeable harm at all, and in fact we are all exposed to some level of background radiation all the time."
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63wbl5 | How to anti-virus scanners scan for a virus? How do they tell what is and isn't a virus? | Repost | explainlikeimfive | {
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"Most modern antivirus programs scan for virus in a variety of ways simultaneously. Most will use some combination of known virus \"names\" (common file names and extensions that have already been identified) and a heuristic analysis that recognizes specific \"behaviors\" that are considered harmful. For instance, let's imagine that you're a business, and you have a database located on your server. If a program were regularly turning itself on, accessing the data in the database, packaging it, and sending it out through the internet to some place, a heuristic analysis may read that behavior as potentially malicious, and quarantine the program. That doesn't mean the program is a virus, or is doing anything nefarious or harmful in any way -- it's just that a lot of viruses behave that way, and the heuristic analysis is just looking for a set of behaviors. I actually work for a company that makes a kind of data integration software that does just that -- accesses data in a database to be made available to different partners for different services. We often have to work with our clients to set up exceptions so that our files don't get quarantined (or in some cases, outright deleted) by their security software."
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63xpmr | What exactly happens when we die of "natural causes" or old age? | Repost | explainlikeimfive | {
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"As we get older (on the span of hours), our cells die. To replace them, our body splits living cells into more cells (mitosis). Sometimes, the two copies of the cell aren't perfect. Generally, cells work correctly and everything is good, even if there are some mistakes in copying DNA for the cell split. As we get really old (on the span of decades), these mistakes add up, and eventually, our cells are not able to split quickly and correctly enough to counteract natural cell death."
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63zpq2 | How do streaming websites like Netflix etc. protect their videos from downloading? | Repost | explainlikeimfive | {
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"The monthly subscription price is cheaper than buying the hard drives necessary to save the shows you might download. People don't want to pirate content, its just that when someone wants to charge an unfair price for it, or tie it down with all sorts of BS use restrictions, people will. Netflix proves that if you ask people to pay a reasonable sum for content and provide it in a nice, easy, manner, you don't have to worry about piracy. Edit: Seeing some of the reply comments I really think you can't read my comment without also reading /u/tomatoaway 's comment (and I would like to think vice versa as well).",
"Rather than sending the whole video as one continuous UDP procession, you can instead split it into HTTP packets and send it. These packets can then contain cookie-specific information that only correctly parse data for the current web client, so copying and pasting the video address into another browser won't work because it lacks the same cookies (or that cookie is already in use). Most browsers worth their salt let you jump around this though, by holding a record of all packets that were recieved and letting you save them externally. Edit: I should also add, [don't use Netflix/Chrome if you value an open internet]( URL_0 )",
"It's not a simple video file that you would download from a torrent or through P2P. It's an adaptive stream using what's probably a proprietary format. Meaning, if your connection slows down, the quality will adapt and look blurry. If your connection is fast, the quality will get better. Most offline video players support something called variable bitrate (VBR) but it's not quite the same thing. That isn't really the issue though because if people wanted to get around that and save the videos they could. But the point is that it's not worth the effort when the subscription is so cheap and they can watch the shows immediately when they're released. With that said, people *do* download Netflix shows from torrents so it does happen. Also, I believe Netflix started allowing offline viewing not too long ago so that probably makes it easier. Another important point that makes it more difficult is that Netflix doesn't download the whole movie. If you pause the stream, it will only buffer so much ahead of where you are. This also allows it to pick up where you left off if your computer crashes. So there is a constant communication between your browser and Netflix that makes downloading videos a bit more tricky than they otherwise would be.",
"There are always ways around it. It is difficult to download it as a file, but you can get a program to record the screen while it is playing and save that recording. I remember when I was big into downloading and got some music, but it was DRM protected so I could not copy it to another device or burn it to a disc. So I got a program that plays and records a new file and that was a good way around that.",
"While I don't know about the Netflix specifics, I worked in a similar system 6-7 years ago for a music streaming service. I was responsible for this area. While I can't go into details, up to now, we still haven't found anyone that 'cracked' the system. The only way to 'download' the music from that system is by recording the audio output in realtime. I developed a real-time encryption server that encrypted the music as it was being sent, and was based on several variables and independent of each user. We also had the audio data encrypted in a different format in memory and only decrypt it in small blocks (again based on several variables) when sending it to the audio device. I was approached by both Spotify and Netflix due to this project but ended up refusing as I knew part of what they wanted was the algorithms I developed and they were at the time property of the company that employed me.",
"They don't really, its trivial to capture the stream and save it to disk. But, you don't really gain anything from doing this, as you can watch whatever you want, whenever, so all you do is fill your harkdisk with files you don't need. If you wanted to, you could pirate them from other sources anyway, so they just make it slightly trickier than doing that. No point making it any more secure.",
"They don't not really well they do take some steps but it's annoying to pirates than anything else. Worse case scenario is people would just record the video right off their screens if need be to pirate the video. You don't even need to go that far though because there are ways to grab that data straight from a web browser. Thing is that Netflix is convenient and cheap enough that most people don't bother with that usually and the ones that do wouldn't have paid for the service anyway. They even actually added the ability recently to download stuff for viewing offline to even further the convenience aspect.",
"Pirate here. Been doing it for almost 10 years from sites like PirateBay, Demonoid, Kickass and even Mininova (back when it was good). Netflix really can't protect their stuff from being downloaded fully. They can protect it from things like Extensions on Google Chrome (like video downloader professional) but if someone has recording software, like Bandicam, and uploads it on a website? then it can be downloaded of course but the quality isn't that great. However most people don't download Netflix original content (house of Cards, Daredevil..) because the membership fee is so cheap, maybe something like The Walking Dead because it doesn't hit Netflix til later in the year after it finishes off the season on AMC. Personally I don't see a point in pirating Netflix original shows because of how cheap it is and there are even shows and documentaries that are old enough that you'd be hard pressed to find on any pirating website. The only people who do are those who're tight for cash or live in countries where Netflix isn't available or the show itself is not available on Netflix in their region."
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6416z5 | For websites, what's the difference between .com, .org, and .net? | Repost | explainlikeimfive | {
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"The idea was that .com would be used by general-purpose commercial entities, .org would be used by non-profits, and .net would be used by network providers. There's no policing or enforcement of this. Anyone can register a .com, .org or .net and they behave identically."
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64186p | Why do some products say "refrigerate after opening" when they can sit on a shelf at a grocery store at room temperature? | Repost | explainlikeimfive | {
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"Those foods are usually vacuum sealed, and are therefore protected from contaminants. Combined with the preservatives inside them, they can sit on a shelf for months or years and still be edible. Even most foods that have a \"best by\" date, are still perfect edible months or even years after they have \"expired.\" But once you open a product like that, you increase the risk of contamination which may cause the food to spoil. Keeping it refrigerated slows or prevents the growth of bacteria that may put the food off."
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642rug | Why do most females "throw like girls"? | Repost | explainlikeimfive | {
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"It's just from lack of proper instruction. At least in the US, people (boys and girls) who don't play baseball or softball aren't taught proper throwing mechanics, and the \"elbow in front of the hand\" technique is just what your brain thinks needs to happen. Try to throw with your non-dominant hand and see if you \"throw like a girl\" I bet dollars to donuts you will.",
"People in this thread have mentioned that girls who \"throw like girls\" don't have athletic training, which is definitely true and almost certainly the primary factor. However, it would be unfair not to mention that women are physically weaker than men. Studies have suggested that nearly all women are weaker than nearly all men. [Graph.]( URL_0 ) I mention this only because OP asked if there was a physical difference. There is, it's just not the biggest factor.",
"\"Throwing like a girl\" is really not knowing how to throw properly, lack of practice, and a lack of muscle memory. Your left arm is evidence of that. The phrase most likely came about because boys have historically been more interested in playing sports while girls were often actively discouraged from playing, leading to the belief that an inexperienced arm is a \"girls arm,\" so to speak. There is no structural difference between a girl's and boy's arm that would make someone throw a ball differently.",
"Blah blah triggered etc anyway this is actually interesting my sister and I were both pitchers in a softball league, it took her a lot longer to get the hang of it underhanded but once she did she was more accurate then me although my pitches were way faster. When we threw overhand no matter how many times they tried to beat It into her head she always \"threw like a girl\". All the guys got it immediately they threw like a hardball pitcher while all the girls did this weird throw using a shit ton of elbow and the arm would only extend at the last minute causing an extremely weak throw overhand. Personally I think it has to do with how the brain works. Only 1 girl got the hang of it at a decent rate out of the 10 that were on the team. After a few years that weird throw was eventually ironed out of their brains but they all did that weird elbow throw for ages. Science dictates that most girls tend to be better right hemisphere and men better left hemisphere so I would say that has something to do with it. Dudes tend to be really good at replicating actions and things while women seem better at coming up with original ideas and planning for most scenarios. At the Olympic stage women are 10% weaker than men which is negligible. This gap become a lot wider in normal everyday life as women tend to be smaller then males. When you take all the feminism and bullshit out of it and look at the data it can be really revealing."
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6430kq | What makes your body decide you're allergic to certain things? | Repost | explainlikeimfive | {
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"An allergy is the incorrect identification by your body of a chemical as being toxic. Some people are allergic to foods such as nuts because their bodies identify chemicals in those foods as being toxic, while bodies of people who are not allergic do not identify those things as being toxic. It comes down to the receptors on the surfaces of the cells that detect toxins."
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649yxb | Why does no other animal have their own language like humans? | Repost | explainlikeimfive | {
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"Some do, mostly whales and dolphins are thought to have some of the most complex languages other than humans. Bottlenosed Dolphins for example, have been shown to have \"name clicks,\" sounds other dolphins use to get their attention. Human researchers have reproduced these sounds and can still get the same dolphins attention."
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64ath9 | Why are cartoon characters always drawn with 4 fingers rather than 5? | Repost | explainlikeimfive | {
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"according to this: URL_0 because it was cheaper (quicker) this way. (also that's why there are exceptions to this rule, like God in the Simpsons, main characters in Disney movies, etc)",
"In the sense of practicality, it's cheaper and much easier to draw. It's basically a work around that made animation much easier to produce. Obviously the hand of a character plays a vital role when trying to depict an action or emotion, so it is crucial to animate the hand more effectively without the burden of adding a finger. However, some shows are starting to include the fifth finger. One example is Steven Universe. Consider a YouTube search of why early Disney Characters wore white gloves. It could tie its way into answering your question."
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64b0ev | Why do we get heartaches when feeling sad | Repost | explainlikeimfive | {
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"I recall it has something to do with stress and blood flowing rapidly from your heart to throughout your body leading to that \"heart broken\" feeling.",
"You got heartbroken by an ex too? :(",
"Increased levels of cortisol I'd imagine. Also, when you are emotionally distraught, you breathe less uniformly. Leading to a build up of lactic acid resulting from anaerobic respiration; which can equate to feeling physically exhausted."
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64bcom | Why are chemical weapons seemingly more abhorred than conventional weapons? (Chemical weapons are "banned" from warfare etc.) | Repost | explainlikeimfive | {
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"dg0tvdm",
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"text": [
"It is has long lasting effects, it kills indiscriminately, and can get out of control very quickly.",
"World War 1. They were used extensively by both sides, didn't prove to have much strategic value to winning a battle, because you can't go in the area you just dropped mustard gas on either, and they cause a slow, particularly brutal death compared to conventional weapons.",
"It's usually a pretty particularly fucking brutal and vicious way to kill someone, and it isn't as quick and 'humane' as a bullet. War is fucked up, but we need certain rules to prevent atrocities like the Rwandan Genocide (the first case of rape being officially declared a weapon of war)."
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64cbel | Why is the right hand the dominant hand for most people? | Repost | explainlikeimfive | {
"a_id": [
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"text": [
"I'd like insight. I'm decent with daily tasks with my left hand and was an excellent pitcher in baseball. If I was lefty I definitely would have made the majors if the same shoulder injury didn't happen to the other. (osteoarthritus at 16) now I have a little boy who I try teaching everything lefty. Thinking it was taught not genetics. He always ends up using his right hand by the end of it."
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64ieb4 | Why do we get dark patches under our eyes when we haven't slept enough? | Repost | explainlikeimfive | {
"a_id": [
"dg2k0s2"
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"text": [
"Increased cortisol from sleep deprivation causes dilation of blood vessels, which causes the bags under the eyes."
],
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64ipxr | What's the difference between unleaded, plus unleaded, and premium unleaded gasoline? | Repost | explainlikeimfive | {
"a_id": [
"dg2fhvk"
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"text": [
"The Octane rating is different for each one. Unleaded starts at 87 unleaded + is usually 89 and super is usually 91 or 93 depending on where you live. The octane rating is the fuel's resistance to combustion. The higher the rating the hotter the fuel has to be in order to light off. High performance engines operate at higher temperatures and pressures so they need a fuel that won't light off before the engine is ready. When this happens it can cause severe damage to your engine, but if your engine doesn't need it you're just wasting money."
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64iry7 | What is laughing and why do we do it? | Repost | explainlikeimfive | {
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"text": [
"Laughter is an instinctual jocular reaction to the inevitable ironies relevant to survival; sex, food, water, sleep, relationships to others, excretion, dangers from the elements, death, etc. Hypotheses as to it's evolutionary origin run the gamut. I favor the ones that claim positive responses to inevitable unpleasantness are adaptive for us, as negative responses to them would cause dysfunction through avoidance, thereby magnifying the problems.",
"Below is an explanation I recall. Laughing has a similar effect to panting, it helps increase our energy levels to perform a task. Panting out loud also lets others around us know that we've found something good like a fruit tree and that it's safe to approach it without risk. Over the course of many years it helped us to find energy, i.e. be happy about things that usually would bore us to death. This eventually lead to the creation of jokes which help us artificially find happiness in otherwise boring or sad tasks which we were under obligation to complete.",
"Laughter, at it's core, is a natural reaction to avoiding death/danger that evolved in order to alert others in the tribe that you are alive and the area is safe. This is the reason we find slapstick humor so funny. Simple things like a pie-to-the-face, or slipping on a banana are funny even to chimps, because they also share a similar evolutionary trait."
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64itcy | Why do we twitch in our sleep? | Repost | explainlikeimfive | {
"a_id": [
"dg2gt8v"
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"text": [
"Basically your brain has a reflex to check if all the parts of your body is still alive. During your sleep, it happens that your brain, as it notices your catatonic state, feels the need to check if some parts of your body are still alive. It does so by sending impulses to the muscles through the nerves in order to obtain a response. The impulse to the muscle is the twitch you have. So don't worry: it's just your brain doing his job at making sure you're fine"
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64j0qu | How computers store information, even when they're off | Repost | explainlikeimfive | {
"a_id": [
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"text": [
"There are two types of memory, firstly volatile such as RAM which is consumed while the machine is on and needs power to keep it running. Second is non-volatile and will not be lost on powering off, such as hard drives and SSD memory. Hard drives store the states in charge, i.e. Positive or negative charge for 1 or 0. SSD's have essentially tiny switches which can be set to these positions. Because electricity is then not needed to maintain this information you can safely power off keeping everything in position."
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64jbt5 | Where do electric eels get their electricity? | Repost | explainlikeimfive | {
"a_id": [
"dg2rlus"
],
"text": [
"Ions. It works just like the way electrical signals travel down your nerve cells, but in the electric organ of the eel, the cells are setup more like a battery than the \"communications wires\" of the nervous system. Just like with nerves there are ion pumps on the cells of the electric organ that maintain an unbalanced chemical and electrical gradient across the membranes of the cells, with more positive ions outside the cells than inside. This means there is a voltage across the membranes. When the signal to discharge arrives at the organ, ion channels open allowing certain ions to flow in, and certain ions to flow out, generating an electrical field as the current flows."
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64ji6s | Why do words start looking weird if you stare at them long enough? | Repost | explainlikeimfive | {
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"text": [
"It's called [semantic satiation](Semantic satiation - Wikipedia URL_0 ). According to Wikipedia: > The explanation for the phenomenon is that, in the cortex, verbal repetition repeatedly arouses a specific neural pattern that corresponds to the meaning of the word. Rapid repetition makes both the peripheralsensorimotor activity and central neural activation fire repeatedly. This is known to cause reactive inhibition, hence a reduction in the intensity of the activity with each repetition. Jakobovits James (1962) calls this conclusion the beginning of \"experimental neurosemantics\". So tl;dr, based on my admittedly basic understanding: after reading a word over and over, your brain goes \"we're seeing that same signal too much, better tone it down\" and makes itself less sensitive to that word, which is why the word starts to sound less meaningful",
"This is really good question, and so awesome that it has an actual answer. I swear this happens to me more often than it probably should."
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64jto6 | How will a self-driving car react when facing a choice: killing the driver or a pedestrian? | Repost | explainlikeimfive | {
"a_id": [
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"text": [
"There wouldn't be that kind of decision baked into it, deciding which lives to kill. It would follow the standard programming for collision avoidance. If it detected something heading toward it, it would brake, or steer into an available space to avoid the collision, or both. Nothing is perfect. Humans do this already. If a ball bounces into the road, you stop or swerve. Hopefully paying attention as you're supposed to at the lanes and traffic around you so you always have somewhere to go in such a situation. An automated car would do the same thing. The default solution would be to hit nothing. It doesn't matter if its a person or a vehicle. If the sensors detect a probable collision it would slow or move to prevent it. A person is just another thing not to hit. You would have code that also makes sure there is an out in a situation, such as making sure cars are spaced appropriately enough that there's an escape lane, proper distance between vehicles, and everything else. Are things perfect? No, but people aren't perfect either. Accidents happen, usually because of someone doing something stupid, like running into a street."
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64ke6y | Why do we forget whole chunks of time when we are "blackout drunk?" | Repost | explainlikeimfive | {
"a_id": [
"dg2v7rg"
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"text": [
"There's a part of your brain called the hippocampus that is believed to be important to the process of saving your thoughts and sensory experiences into long term memory. Excessive alcohol consumption appears to interfere with two neurotransmitters (gamma-Aminobutyric acid (GABA) and N-methyl-D-aspartate (NMDA)) that are used to communicate between neurons in the hippocampus, and so the theory is that the alcohol stops the chemical process of creating memories until your blood alcohol level decreases."
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64kfpn | How do airlines often overbook flights? | Repost | explainlikeimfive | {
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"Because they intentionally overbook them. They know that some people don't show for flights. They have pretty good stats on how many people, on average, won't show, so they know how many to overbook each flight. An empty seat is lost money. Sometimes there are fewer no-shows, and that's an overbook. They do have to compensate people for bumping them from the flight, but that's cheaper than having unsold seats.",
"It's intentional. If someone doesn't show for a flight or cancels, that's money the airline doesn't make on that flight. Overbooking gives them some cushion for cancellations and allows them to make more money per flight.",
"Large planes use almost the same amount of fuel whether they're half empty or packed, and airline companies know this. They also know from experience that some small percentage of booked passengers don't show up. They maximize profit margins (the margins on cheap seats are razor thin) by booking 102 seats on a 100 seat plane and assuming that at least two aren't gonna show. Usually they're right, but occasionally all 102 people show up and someone's waiting for the next plane.",
"As a crew scheduler, If a pilot or flight attendant gets sick somewhere we don't have reserve staffing I have to overbook flights to get a back-up out there. It's better to strand 1 person in Chicago than 97 in Fargo. Plus if the plane doesn't leave Fargo then planes that the crew in Fargo were supposed to operate later in the day might also get stranded. It can easily snowball into a huge mess, better to ruin one person's weekend than completely screw over 97 (or more) others. Edit: ok back from work let's see what Reddit thinks Edit numero dos: Reddit had 3 misunderstanding and 2 jokes about beating up an old Dr. I think I righted the misunderstandings and doubled the joke total.",
"they know that some people will not show up for the flight, so it is prudent to overbook to make sure they fill the flight, and if their statistics betray them, they will bump them to a later flight for a few hundred bucks. cheaper to pay to bump people on occassion than to fly with 10 empty seats almost every time.",
"Here's an outstanding video which should cover your question. [I hope this helps!]( URL_0 )",
"Overbooking flights in pretty common because airlines know a certain percentage of people will miss their flight or change their plans. Depending on the particular route it might be more or fewer seats. A Tues 8am flight from Chicago to New York probably has a lot of changes since it's mostly business travel, so it might get oversold by more seats that other flights... say a Sat AM flight to Orlando, which is much less likely to have changes since a family planning a trip to Disney World is going to keep their plans for Disney World.",
"Further how is this not false advertising when they sell more seats than they have ?",
"Airlines want to make as much money as they can, which means operating each flight as close to 100% full as possible. Imagine you're operating an airline. Most of the time, a few people don't show up for their flight. So you start selling a few extra tickets for each flight. If everyone shows up, you don't have seats for them all. But everyone showing up is very unlikely. Actual airlines use statistics to determine how many no-shows are likely to happen on each flight. They factor in everything, such as where the flight is to and from, age of the passenger, gender of the passenger, if they're flying with anyone else, the time of the flight, the weather that day, and a *ton* of other factors. With all of this information, they can get a *very* good estimate of how many people won't show up for a particular flight. So they then go ahead and sell more tickets for that flight, based on their estimate. Most of the time, there's no issue. Everyone who shows up gets to fly. But some of the time, there is an issue, because more people than expected showed up for the flight. In these cases, airlines typically offer incentives for travelers to voluntarily give up their seat on the flight, and although this costs the airline some money, the extra money they make by overbooking to get every flight as full as possible more than offsets this cost.",
"When I travel for my company my secretary will book multiple flights in case I want to leave earlier or later. We only get charged for the flight I take."
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64ksls | Why do many guys find legs, foot, stockings, pantyhose, etc. sexy? Aren't those parts far away from sexually sensitive zones, and not part of the female secondary sex characteristics? | Repost | explainlikeimfive | {
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"dg2xsit"
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"text": [
"Actually in the primary motor and primary somatosensory cortexes, the area of the brain associated with the genital areas is very close to that part of the brain associated with the legs and feet. The brain overlap theory states these areas can communicate with each other leading some individuals to sexualise feet. URL_0"
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64lnqg | At what "fps" do a human's eyes see at? | Repost | explainlikeimfive | {
"a_id": [
"dg34v7o"
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"text": [
"Eyes don't have a FPS. Your eyes take in a constant analog stream of light (until you get down to the individual photon level). The speed at which you see is mostly limited by the speed it takes the nerves in your retina to process and send the information to the brain. At that point, your brain processes the signals coming in to make your consciousness \"see\" whatever you are seeing. This is a combination of what the retinas are actually seeing, and what your brain \"fills in\" as what it thinks you should see. This is where a lot of optical illusions happen. If what you are asking is at what FPS do we need to see something for it to appear real, that's different. Things may appear real at 24 fps (the traditional cinema fps, which was mostly chosen because it was the slowest that would be flicker free), but that's because your brain is good at filling in those details. Watching the same video at 60 or 24 fps should be pretty noticeable. Some people think the slower traditional cinema speeds are better because of the motion blur that naturally occurs at the slower filming speed. 60 fps is too crisp and clean in motion scenes, not reproducing accurately the motion blur that naturally occurs to us (incidentally, this gets added in during post production in higher fps films now). But it's also an argument that we are seeing more frames than people previously thought. How many frames can your sight really differentiate? There's no solid answer for that. And it may vary wildly between individuals. Many people claim to be able to see a drastic difference between a 144Hz monitor and a 60Hz one. Others may not. But this also depends on the application. For instance, gamers often want the absolute highest refresh rate because they don't want to miss a single frame of action, in case that frame happens to have the critical info they need. But they often have been training themselves for years (not deliberately, necessarily) to be able to pull the data out of those frames quickly. The brain is pretty fluid in its abilities, so having it change how it processes visual stimulation is not surprising at all."
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|
64lqtl | With the universe constantly expanding in all directions, is there a centre of the universe and how do we find it? | Repost | explainlikeimfive | {
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"No, the general thought is that there is no center. Everything is moving away from everything else and there is no central point.",
"The center is right where you are standing. If you hopped in a time machine that was stationary but could travel through time like the one in H.G. Wells's \"The Time Machine,\" and set the dials for the beginning of the universe, you'd zoom back through time as the universe shrank around you. The universe would shrink to a size too small for you and your time machine to be in before you got to the beginning though, and even before you got to the end of the [cosmic inflation]( URL_1 ) period, at which time the universe was about the size of a grain of sand. On the other hand, we can \"see\" all the way to the cosmological horizon already, the edge of the observable universe. What we see there is photons that were emitted about 380,000 years after the start of the universe. Before that, the universe was so densely packed with stuff that any photon emitted by one atom would be absorbed by another atom almost immediately. Those photons have been travelling for so long and so far that they are all [redshifted]( URL_0 ) to microwaves, but in any direction, that redshift indicates a distance of 46.5 billion light years. The observable universe is a sphere 93 billion light years across, with you at the center.",
"It's all the centre. Like the surface of a balloon when you blow it up, but with the extra dimension.",
"Since everything is moving away from everything else, it will appear as though the point of observation is the center of the universe. That makes you the center of your universe. Have a nice day!",
"The more space between two object the faster the expansion is. This is due to dark energy. This means that where ever you are in the universe everything is generally moving away from you (with exceptions due to gravity). This means that all points appear to be the location of the big bag and the center of the universe from that locations frame of reference. Therefore it is not possible to find the center ( if there is one ) with this method. An easy way to demostrate this is to take a rubber band cut it so that it is a straight line and make different points on it with a marker. Stretch it and check the movements of each of the points relative to several different frames of reference and you will find all things seem to move away from the frame of reference you choose.",
"This [video by Minute Physics]( URL_0 ) explains it rather well.",
"Has any of this ever been animated? It might be a lot easier to understand if there was a visual to illustrate the concept. I don't know, it may be so complicated that a visual model is impossible."
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64n99i | Why are controversial moments in sport or politics dubbed "gate", e.g "towelgate" or "deflategate" | Repost | explainlikeimfive | {
"a_id": [
"dg3ho3x"
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"text": [
"Um, because of watergate? EDIT: Oh right, most of reddit was born long after Watergate, forgot :) Well this happened, it was a thing: URL_0"
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64q6u8 | How does a bank work? | Repost | explainlikeimfive | {
"a_id": [
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"text": [
"A traditional bank offers two services: Loans and savings. Loans are where the bank will lend money to a person or business, who will then pay the money back to the bank (plus interest). Savings are where a person or business will ask a bank to hold onto their money for them and the bank will pay them interest over time. The money that banks use for loans is the money deposited by people saving with bank. Banks make money by charging a higher interest rate on loans than they pay out to savers. For example, a bank might ask for 6% interest on a £100 loan and then pay 1% interest on a savings account with £100. This means that the bank will make £5 in profit. Investment banking is quite different. An investment bank offers advisory services to businesses looking to \"float\" themselves on the stock market. The investment bank can also buy all of a company's shares when they are issued and sell them to investors on the company's behalf (saving the company a lot of time and effort with finding investors). The investment bank makes money by selling the shares for a higher amount than they paid for them. As investment banking is based on a lot of speculation (trying to predict changes in the market), it's inherently risky. If an investment bank buys 10,000 shares in a company at £20 each, it could sell them for £25 (25% profit) each if it correctly predicts the market but it could also get it wrong and have the shares be worth less on the market than what they paid for them."
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64qo7r | is the universe as long as it as tall, or does it expand farther in one direction than the other | Repost | explainlikeimfive | {
"a_id": [
"dg48c3y"
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"text": [
"The universe is likely infinite in size. The observable universe, the part we can see, is limited by the speed of light and age of the universe so it is a sphere."
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64qwn8 | What is a raspberry pi and why is it so significant? | Repost | explainlikeimfive | {
"a_id": [
"dg4ac9u"
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"text": [
"They are very small, very cheap computers. They have very little processing power compared to more expensive devices, but they are powerful enough to run a basic desktop OS. You can use them for all sorts of things such as emulating old video games, or as a media player, a home automation controller. They also have generic IO connections so they can be used to control things like motors, allowing you to use them for basic robotics for example. They're aimed at hobbyists mainly. It's up to you to configure/program it to do whatever you want."
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64s82v | How did programming start? | Repost | explainlikeimfive | {
"a_id": [
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"text": [
"In a couple of ways, depending on how you look at it. The first \"programmable machines\" in the modern sense were looms and player pianos. Instructions would be encoded and punched into paper tape or cards, and the loom would weave patterns/piano would play music based on whether a lever/cog/puff of air made it through a hole or not. The first electronic computers were single-purposes devices. To change their programming you very literally rewired them. These early computers would have \"wiring boards\" that consisted of pegs and wrapped wires, and you'd wrap different pegs together to change the program. With the advent of stored-program computers, things got a little easier. The earliest ones would have a bank of switches as wide as a memory word, and a button that said \"store\". You'd flip the switches to represent a word of memory (on switches were 1 bits, off switches were 0), hit \"store\" and that word would be stored into memory. Believe it or not, they actually made these awesome giant-roller things with pins on them like music boxes that they'd roll up to the computer and hand crank - the pins would flip switches on and off and it made life easier. Early computers also used punched cards, which got their start as I said above with looms (and theorized by Charles Babbage for his machines), but which really hit their stride during the 1890 United States Census, where they were used to input census data. There wasn't a \"program\" per se in this case: cards would be put in a machine and holes would allow wires to touch, completing an electric circuit and incrementing a counter. At the end of a batch of cards, you could look at the counters to see what was tallied. However, since programs are just data, and because data processing equipment using cards was plentiful and well-tested, using cards to store program data became common place. The principle was the same as above: a card would be fed into the computer and a hole would allow an electric circuit to be completed, flipping a bit to \"on\" and storing that word somewhere. Eventually the programmer would say \"go\" and the stored program would be run. The code that a computer executes is called its \"machine code\". The number \"7\" for example, when interpreted as an instruction, might mean \"add the following two numbers together and put the result in memory location 382\" or whatever. Different types of computers have different machine codes, referred to as \"instruction sets\" or \"instruction set architectures\" (there's more to it than that, but that's the gist of it). Programmers used to write machine code directly. They'd put those numbers into whatever format was accessible to the computer. Then in the 1950s, we got the ideas of \"assemblers\", which would let you use \"mnemonics\" (easy to remember names) for instructions. So instead of saying \"7 2 4\" to add two and four, you could say \"ADD 2, 4\" and the assembler program would translate it into the appropriate machine code. Assemblers are just programs themselves, so the first assembler was written in machine code and then the second one would be written in assembler, and assembled by the first one, and from there on out you'd basically pulled yourself up by your own bootstraps. Compilers are the next level up. A compiler translates a (usually more complex-for-the-computer-but-easier-for-the-human) language to another language. Often they transform a language like C or C++ or whatever to assembly instructions or directly to machine code, meaning the programmer can write \"print 'hello'\" or whatever, instead of having to write whatever machine code or assembly the computer needs to write things to the screen/file/whatever. Sometimes the compiler generates machine code for a machine that doesn't really exist, called a *virtual machine*, and an emulator (a program that interprets the instruction set of that virtual machine) is run to interpret that program. This is how a lot of languages work, like Python. (There's a huge variety of compilation and interpretation strategies out there, further complicated by things like \"just-in-time compilation\" and what have you, but that's well beyond the the scope of this answer and at the end of the day is really just details...)"
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64wb10 | Why is the wind from fans cooler than the rest of the room? | Repost | explainlikeimfive | {
"a_id": [
"dg5izec"
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"text": [
"This is the same as other forms of wind chill. We are constantly losing body heat to the air around us, and in doing so we cause the air next to our skins to warm up. This heat eventually dissipates, and we lose more heat to the now cooled air. Wind chill speeds up this process by replacing the air around us as we are warming it up, in essence making us feel the \"real\" temperature of the air by blowing away the layer of body-heated air next to our skin."
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64x3it | Why are photos rectangular not circular? | Repost | explainlikeimfive | {
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"Other's have addressed the fact that the image from the lens is round. Something not covered is that you generally cannot use the entire circular image. The image quality is terrible at the edge (soft focus), and the light falls off (image is darker). So you have to chop some out. Since you have to chop something out, what shape should you choose.... 16 century. You want to paint on canvas. You have to stretch the canvas on a frame. You go to the guy that makes frames and say \"make me a circular frame\". He laughs at you, points at his stock, which is all straight sticks. Why? Because it is easy to cut straight sticks out of a log, and it wastes the least material. Any idiot can cut a straight line, and then with a bunch of straight sticks you can make any size frame you want. If you want a different sized circular frame, that means a different radius, which means a different cut. Instead of storing sticks, he needs to store entire boards, and then custom cut the wood for your frame, and throw a lot of wood away. Your $30 rectangular frame becomes a $450 circular one. Hmm, maybe you'll paint a rectangular painting! Aesthetics. I want to put something interesting in the foreground. In a circular painting, it has to be dead center. So, I don't have a lot of artistic license. In a rectangular one I can put it left, right, near center, or way off. I have choices. Then I need to frame the painting. Frame shop is going to have a lot of straight narrow sticks to make a frame from. It is easy to cut glass and mattes in straight lines, very hard in circles. Do you want to pay $300 for framing, or $2500? By the time cameras were around, images in commerce was a thing. Billboards. Theater posters. Flyers. Cereal boxes. Pages of magazines. Newspapers. Books. All needing images, and a photograph is cheaper than paying somebody to draw or paint something. These objects are all mostly square/rectangular for a multitude of reasons. So, we want square/rectangular images to put on them, mostly. Early cameras did not use film - photographs first went directly on metal. That was the final image. Which is cheaper and easier - cutting a rectangular piece of metal, or a round one, do you think? Soon they went to glass plates for the film. Think it is easier and cheaper to cut glass in rectangles or circles? Which is easier to transport? The cameras were those accordian looking contraptions where you put your head under the cloth. The accordion part was so you could move the film plate closer or further from the lens to focus. It is made of pleated paper/felt. Ever tried to fold paper into a cylindrical accordion? Pretty hard compared to a rectangle. The camera is basically several rectangular frames - one to hold the lens, one to hold the plate, and then the base. Why rectangular - easy to build. And, these were HUGE. If you wanted a 16x20 image, you needed a 16x20 camera. Everything is easiest to make rectangular, so they will be. So you want to carry all this material, only to get a photograph 15\" round? No! You aren't going to throw away parts of the image. Everything is rectangular, so here is your 16x20 image. And so on. Everything makes rectangles preferable, cheaper, and easier in the vast majority of cases.",
"Because they're captured on a rectangular segment of a roll of film- or, nowadays, a rectangular array of light-sensitive electronics. This way, it's easier to print the resulting images on rectangular paper, or display them on a rectangular computer or phone screen.",
"Let's use a digital camera, as this is simply easier. The image itself is square because that is the shape of the image sensor, which collects the light. The sensor is square, as it is made of millions of pixels, each of which collects and measures the amounts of red, green and blue light to create the colour we see as the image. These pixels are square, so it is easier for millions of these pixels to simply make up a larger square, rather than any other shape. However, the lens is circular. Why, then, does this not create a circular image? As it turns out, the image is circular when it comes out of the lens. The sensor just takes a rectangular image from inside this circle. Check out the \"Image Circle\" wikipedia page, there's a good image. I would link it, but I'm on mobile. So why is the lens circular? Simply put, it's just easier to make a circular lens. Lenses are ground to the correct shape on a lathe, which spins the lens and grinds away material. It would be nearly impossible to do this with a rectangular lens. A square lens would also not bend light in the same way as a circular lens, without more complex shapes. A circular lens alters the light uniformly, while a square has corners and edges. The aperture (iris) is easier to make as a circle, squares are difficult. There's more, advanced reasons why circular lenses are used, but this is ELI5 and you only asked for why the photos are rectangular. Hope this helped!"
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650c6i | How do televisions measure their viewership ? | Repost | explainlikeimfive | {
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"There are survey companies. One is called \"Nielsen\", like \"The Nielsen Ratings\" you might have heard about. By a process of magic, they select your household and send you an envelope. You fill out details about your household: how old you are, how many live there, what kind of shows you like to watch, radio stations... and you mail that back to them. They take that information and enter it into their database. They thank you. They tell you they may call you up and ask you questions, or maybe email you, things like this. Back in the day, the could also send you an electronic box to hook into your TV. This box would register what you watched as you flipped through the channels... and like Windows 10 but nicer, send that information back to Headquarters. So they have a group of people//households giving them information. They compile that information, think \"what if this was everybody\" type of thoughts, and then generate their ratings for TV shows."
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651j6o | How was a language first translated into another language? | Repost | explainlikeimfive | {
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"Point at tree, repeatedly say \"tree\" until the other person says the same word a few times. Rinse and repeat."
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651ro8 | How do the O2 monitors you clip to your finger work? | Repost | explainlikeimfive | {
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"So those finger clips don't actually measure oxygen saturation. They measure how much infrared light is absorbed by the cells. So let's say you were in a burning building and happen to inhale quite a bit of smoke. The O2 probe would probably read 100% because most of these finger probes cannot tell the difference between oxygen and carbon monoxide.",
"The protein in your red blood cells called hemoglobin has a small molecule of iron on it. Hemoglobin carries oxygen in your body, and the oxygen is stuck on that molecule of iron. When the iron has oxygen stuck to it, it's a slightly different color than when it doesn't have oxygen stuck to it. The finger device shines a light through your finger, and the amount of oxygen in your blood determines the color of your blood and thus how the light interacts with it. Sort of. Edit: thumb -- > finger"
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6561xo | why is smoking bad for you specifically and emotionally what can it do to your body? How long would it take to smoke for it to hurt your body? | Repost | explainlikeimfive | {
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"Gonna assume you mean smoking tobacco. Tobacco smoke contains carcinogenic compounds. These are chemicals that attack the DNA in your cells. 99.9% of the time that just results in the cell dying, and your body replacing it, but a small fraction of cells will become cancerous and start multiplying. Every cigarette is basically playing the cancer lottery. You could get cancer from the first one you ever smoke (*very* unlikely) or you could smoke 50 a day for 40 years and never get cancer (also *very* unlikely). Tobacco smoke also contains tar and other chemicals bad for your mouth, throat, and lungs. Smoking *will* lead to emphysema, and other lung disease, causes high blood pressure, and seriously increases your risk of heart attack and stroke. It also kills your senses of taste and smell pretty effectively. Smoking is never good for you, and it's a habit you should definitely avoid. Trust me. It's inconvenient, expensive, and a total bitch to quit. Edit: Nicotine is a seriously lame drug anyway. You get a little buzz at first, but after you get tolerant to it you get nothing at all except a constant craving to go smoke.",
"Imagine you're at a theme park and you get on one of those white-water rapid rides. When the ride ends, what are you probably going to see? Some of the riders are going to be soaked. Some are going to be at least a little wet. And there will probably be at least one person who didn't get wet at all. That's kind of how the negative effects of smoking work on a group. Most people are going to feel some negative effects from smoking over time. Some are going to get drenched in health issues (like cancer). A lucky few will get through unscathed. In both cases, the more you ride/smoke, the greater the likelihood that your luck runs out. I'm oversimplifying, of course, but I think it's a decent analogy. You get on the water ride assuming you'll get wet, not that you'll stay dry. You should pick up cigarettes assuming they'll cause health problems at some point.",
"There's no recognized \"lower limit\" to smoking safety, one cigarette is theoretically enough to cause harm. That being said, many of the prominent harms from smoking, increased cancer risk, decline in lung capability, are cumulative effects. So the more you smoke, the greater your risk/harm. But *any* smoking is recognized as a risk."
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65628x | Why does ribbon curl with scissors? | Repost | explainlikeimfive | {
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"When you run the edge of the blade of the scissor over the ribbon, you break the ribbon's structure a little causing one side to be stronger than the other. The stronger side curls the weaker side inward creating the curls."
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6562ll | How does more viewers or viewers in general(in tv , youtube) convert into money | Repost | explainlikeimfive | {
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"Advertising. Companies will pay other companies to put their products in front of your eyes. more eyes = more money."
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65663r | Why do men go bald solely on top of the head as opposed to on the sides or on the back? | Repost | explainlikeimfive | {
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"There are different levels of \"why\". There is something different about the hairs in that zone that makes them more sensitive to a particular hormone called DHT. There is a whole series of inflammatory events that slowly kill the follicle. Now, why are the hairs in one spot more sensitive than the hairs in another spot? No one knows.",
"The hair on top of the head is more sensitive to the hormones that cause the follicles to shrink in people who have male pattern baldness. This is why hair restoration procedures can implant hair from the back of your head/neck on the top and it will grow like normal hair (it is resistant to what caused the baldness).",
"I want to know how everybody else in my family has good hair and I was already mostly bald on top by 17. I shaved my head at 19 when I got tired of fighting it.",
"Why can't we grow bald on the back?!?!?"
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6574bb | Anti-aliasing | Repost | explainlikeimfive | {
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"**ELI5 Answer** Pixels are all square. That means they are very good at drawing straight lines, but very bad at drawing curved and diagonal lines, because things start looking jagged. Anti-aliasing uses blur and smoothing to hide the jagged edges so that things don't look quite as pixelated. [Here is a good example side by side]( URL_0 ).",
"Try taking some basic LEGO® bricks (let's use some black 2x2 blocks for our example, part #3003) and try to make a diagonal line with them. You'll find the best you can do looks like a staircase with zigzaggy corners. Now step back and squint a bit so your vision is blurry. The further you are, the less you notice the pointy corners. If you were to do the same thing with DUPLO® bricks of the same 2x2 size and color (part #3437), you'de find a similar effect, but you'de have to be much farther away to make it look less zigzaggy. So how can we get rid of the zigzaggyness? One way, as we saw, is to use smaller bricks (pixels), which allow us to be closer. But there's also another trick you can use. Going back to your original smaller bricks (which are black, on your conviniently white table), start placing grey bricks so that they touch a black brick on two sides. You'll notice the line is bigger, but if you step back and squint, it'll look even less zigzaggy than before. That's because the grey is the color in between the line and the background, which means they blend together better when we look at them. This is a type of antialiasing.",
"*I copy-pasted this from an old post I made on /r/pcmasterrace* To understand how anti aliasing works, I'm first going to explain why it is needed. First you need to know what a sample is. ###How images are rendered Imagine your computer is rendering an [image of a tomato on top of a table]( URL_0 ). In order to render the image each of the 1920 \\* 1080 pixels on your screen needs to have colors assigned to them. This isn't as easy as viewing a video or an image. The tomato can be viewed from any angle, and the pixels will need to be recalculated many times every second to produce a smooth animation. A sample is a light/color calculation that can be thought of as an infinitesimally thin ray of light. Imagine that you have a bunch of these rays of light, and pretend these light rays are 1-dimensional objects - lines - that are going straight through your screen. For those familiar with optics this is called normally incident. Most often each pixel will get one ray of light. Most often your computer runs a [single one of these rays through the middle of a pixel]( URL_1 ) (the surrounding pixels in that image are highlighted to make it easier to see the sample). When one of the rays hits an object in the game, it bounces off and goes back through the same pixel it came from, this time with the color of the object it hit. [That ray then determines the color for the whole pixel]( URL_4 ). ###Why AA is needed Now most of the time this works pretty well. If you have two pixels from the same object that are right next to each other - like two pixels on the inside of our tomato - they'll have pretty similar colors and the image will look smooth. However, when you reach the edge of this tomato, [you'll eventually find a pixel is no longer over top of the tomato]( URL_3 ). The pixel on the left will be red like the tomato, but the one to the right of it will be brown like the table it's on. The difference in color is dramatic. The pixels are either on the tomato or not, there is no middle ground. The problem here is that the pixel's don't accurately represent what's going. If you look at the \"pixels\" drawn over [the image of the tomato]( URL_2 ) you'll see that the area covered by the some of pixel has too much information to be conveyed by a single ray of light. On the right half of the pixel there's the table, and on the left half there's the tomato. Other pixels contain significantly less information. The pixels in the upper left corner of the image have fairly uniform colors throughout them, so when they are reduced to a single sample there is less information loss. The solution programmers have come up with this problem is what we call anti-aliasing. The game engine [takes more than one sample per pixel]( URL_5 ) (either one in each corner of the pixel, a few different samples in a grid formation, or sometimes even in random locations). Some will hit the tomato and some will hit the table. The colors are then averaged together to give you your final pixel color. ###Types of Antialiasing The method of AA that's the simplest to understand is called super sampling anti-aliasing (SSAA). It simply takes more than one sample in every pixel on the screen. Because sample calculations take a while to do, this form of AA is extremely taxing on your graphics card. You're essentially rendering the same screen multiple times. Another form of AA is called multi-sampling anti-aliasing (MSAA). This form of AA has an intelligent algorithm that finds out what pixels need more than one sample, and then simply does more samples on those pixels. This form of AA is much cheaper than SSAA and is also a lot more popular. MSAA doesn't work well for all games. Minecraft is the best example of a game where the edges of objects aren't the only thing that needs to be anti-aliased. Take a look at the insides of block textures. The game doesn't blur anything inside of blocks like most other games do, so SSAA is the best option for Minecraft. There are other forms of AA, but these two are the most popular and the simplest to describe.",
"Apparently Reddit is full of gamers who tell you nothing of the core concept. So let's start with what aliasing is. Let's say your checking to see how often a light blinks. So you decide you are going to check it every minute to see if it's on. You start the timer and you see that the light is on at the minute mark. Aha.. You say it blinks every minute. But wait... What if it was blinking every 30 seconds... And because you were checking every minute, you only saw every second blink and missed the 30th second blink event. So you say... Fine. I will check every 30 seconds now. And yet the question can be asked... What it was blinking every 15 seconds and you only saw every second and forth blink event? Essentially, you were seeing blinks that were partly determined by your speed of checking for them. You saw 1 when there could have been 2,4,6,8 etc. Blinks in that minute. There is a pattern here which I won't get you but this inaccuracy that occurred is called aliasing. This goes on and on and you eventually reach a conclusion. You can only be absolutely sure of the frequency of something if you check it at least twice as fast as that frequency. This is called the Shannon Nyquist sampling theorem. Anti-aliasing is basically the opposite of this and depending on how complicated the setup of frequencies is, methods to anti alias also change. The fundamental method of anti aliasing is simply check the frequency more often in time or space and hope that you are at least twice as fast as the actual frequency. This is called supersampling. You could do something more complicated. For example. You could check every 10 seconds , and also every 15 seconds. This means you will be able to see blinks if they occur at some point for all multiples of 10 and 15 seconds. That's pretty good. By checking at 2 different speeds, you've sort of reduced the need to go faster for one frequency. This is called multisampling Now in a computer for graphics, aliasing occurs because pixels are processed at a certain frequency, change at another and are displayed at still another frequency. This creates the jarring because of aliasing (you aren't getting all processor produced pixels displayed because you screen refresh is to slow for example). You have to use extra tricks in the GPU to makes sure the image does not get jarred. This is anti-aliasing... Performed by more complicated algorithms of the same basic steps above. Edit : A lot people seem to be assuming that the word \"frequency\" only refers to temporal frequency. It doesn't, your assumption is flawed. Before the \"this is wrong\" comment, I recommend you read up on Fourier analysis. URL_0 and URL_1 These links are definitely not for 5 year olds, but are suitable for the poorly informed tunnel-visioned teenagers who are whining below.",
"Depends on the type of antialiasing. They're all very different. MSAA and SSAA work on a pretty simple principle: increase the resolution of the content being rendered. You get more detail that way, which decreases aliasing. SSAA straight up increases the internal resolution of any 3D image. MSAA is more complex and selective, but still works on the same principle. Purely post-process antialiasing techniques like FXAA do not actually change how the picture is rendered at all. It's just a filter overlayed over the image being rendered. Think of an overlay making all colours red. It's that kind of filter. It's just a flat 2D filter overlaying your screen. It doesn't touch any of the 3D rendered model data in any way. Only instead of changing the colour value of all pixels to red it changes their values strategically to try to reduce the colour difference between contrasting parts of an image. This reduces the visual perception of aliasing. There are different hybrid forms of anti-aliasing as well. Some of them are pretty clever in how they achieve their goals.",
"Aliasing, in the most general sense, is a concept in the field of signal processing that happens when sampling a continuous signal. Think of a sine wave -- you could sample its value anywhere in time (assuming the time domain is continuous). But if you don't sample frequently enough, you might not get enough information in order to understand the original signal. As a contrived degenerate example, imagine a sine wave with a frequency of 1Hz. If your sampling rate is also 1Hz, you'd see the same exact value every time you sample, and you'd have no way of knowing that the value was fluctuating in between your samples. This concept extends to more complex signals -- by sampling a continuous signal at discrete intervals, you can lose information. ANTI-aliasing, which is what you asked about, is the set of techniques that can be used to mitigate the problems (known as artifacts) resulting from aliasing. If you give a little more info about exactly what application are you are talking about, e.g. computer graphics, I can provide more details.",
"Think of two squares touching at corners... the image is quite jaggedy. In things such as video games AA predicts what should be in the empty space to create a smoother images on thing objects (such as wires or lines) or object outlines.",
"This Linus tech video covers it. Saw 3 days ago URL_0 TL:DW - pixels are squares like a grid, which makes diagonals shit, so either add more tiny pixels to trick the eye into thinking it is smoother or smooth the colour of the pixels around.",
"Aliasing happens when you try to describe something that changes rapidly, and you can't describe it fast enough. For example, imagine you're measuring a half a meter deep hole, and your measuring stick is only capable of measuring in full meters. Whatever measurement you leave with, you've lost information of the real size; you're left with an approximation. The same thing happens in sound. Say you want to measure a 10Hz wave (moves up and down ten times a second), but you are only capable of measuring it five times a second. You'll never get an accurate representation of the true shape of the wave, and anything you come out with is distorted. This is aliasing. The more samples you make, the closer you get to a real representation what the shape truly is. A guy called Nyquist proved that in order to sample a frequency, we need to sample at at least twice the rate. So, anti aliasing is a way of getting around these fundamental issues in what happens when we lose information in our signals. With pixels for example, the square edges introduce such a harsh transition that we lose information of what goes on between the pixels. An interesting way of reducing this effect includes sub pixel anti aliasing, where you take advantage of the fact that each pixel is comprised of a discrete R, G, B value, smaller than the pixel itself and therefore capable of generating higher 'spatial' frequencies. It has been proven that you can share these colour components with neighbours to try and spoof the missing information, producing what appears to be a much higher quality image.",
"Screens are grids of rectangular dots called \"pixels\"; they're pretty small, but they're still _waaay_ too big to perfectly show curved or even just \"crooked\" shapes. This is most noticeable when computers are drawing shapes; if I draw a circle using only those dots, it'll look jagged. That's called _aliasing_. Humans don't expect their smooth shapes to look jagged, so aliasing makes computer-generated images look less real. _Anti-aliasing_ is a term for techniques you can use to trick people into not seeing as much of that jaggedness. One technique is to trace around the outside with \"lighter\" (less-saturated) versions of the color of the edge. This creates an optical illusion of \"blurriness\" which tricks us into thinking the edge is smoother and less jagged. And less-jagged images look more realistic to humans.",
"Aliasing is a duplication of signals that occurs when a signal is digitized. In the real world, signals like sound and light are *analog time continuous*. This means that their values can take any value at all. For example, a sound signal might have a maximum loudness, or intensity of 99.579 dB, and a frequency of 15 kHz. You can think of a wave as a collection of infinite points, that all together make a continuous wave. Because computers are digital, they can only take a certain amount of point from this wave. Computers measure the intensity, or sample the wave, at a certain rate, to measure the signal. This rate is called the sampling rate. If the sampling rate over twice our frequency, say, ~~20~~ 40kHz, then our signal of 15 kHz can be reconstructed pretty accurately. However, if we have a sampling rate of~~10~~* 20kHz, we will start running into problems. Because the sampling rate is less than our signal, it cannot accurately measure it. The signal reconstructed by our computer will be distorted, and will look like a lower frequency signal, or an *alias*. (will add a picture later for clarity) In order to fix this, frequencies higher than twice our sampling rate are simply blocked. In music files, the sampling rate is about ~~26~~ 44kHz, which means a maximum audible frequency of 22kHz. Since the human hearing range tops out at 20kHz, it doesn't matter that these high frequencies are blocked out, because we can't hear them. Edit: Thanks to /u/ipwnmice and /u/oonniioonn for some corrections.",
"Imagine pixels as a bunch of squares covering a perfectly smooth image. How do you color the pixels so they look like the image underneath? You could color each pixel according to the color of the image exactly at its center. But what if there's detail smaller than the pixel, and you happen to hit a small detail that doesn't represent the color of the whole pixel? You'll color the whole pixel like that small detail, and it will have a color that's mostly wrong. Really what you want is the *average* color of all the details inside the pixel. That means that all the details smaller than a pixel get smoothed out. This makes the image look better and smoother, and can also prevent pixels from blinking on and off as the centers move over small, high-contrast details. It's very hard to *exactly* compute the average, so must anti-aliasing techniques work by measuring the color at multiple specific locations inside each pixel, and mixing together the results. The way you mix things (i.e. [weighting locations differently]( URL_0 ) according to whether they are near the center of the pixel or far away) can affect the perception sharpness, or the brightness of fine details like highlights.",
"So there are a bunch of different techniques for anti-aliasing, but there are two main categories: render-time AA and post-process AA. **Render-Time AA** - These techniques are applied *during* the render of the scene. As pointed out elsewhere, one of the main ways of doing this is by super-sampling, or drawing the scene at a higher resolution before down-sampling it to the display resolution. This can fix both [jagged edges]( URL_2 ) and thin lines disappearing. Nvidia's [page on DSR]( URL_0 ) does a pretty god job of showing how super-sampling helps with both of these. One of the most important differences is that render-time techniques get to use information about the 3d geometry of the world, and only smooth things like the edges of polygons. **Post-Process AA** - These techniques are applied *after* the whole scene has already been drawn. The input to these is just the \"finished\" 2d image. The most common post-process AA is FXAA. The basic idea of these is to look at neighboring pixels and look for big changes in neighboring pixel color. These indicate hard-edges, which are where aliasing occurs. [Here]( URL_1 ) is an image showing the edge-detection steps of FXAA. Once you detect those edges, you can blur them a little, hiding the aliasing. Post-process AA is super easy to add to your game, because you just stick it on at the very end of your render pipeline. Just make sure to apply it before you add in your UI, because all those hard edges in the text and boxes will come out blurry. The problem with post-processes is that it doesn't know if a hard edge is *supposed* to be there. It may end up blurring some of your textures, especially if there is text on them.",
"Pixels are square, and solid colored outlines look jagged if the squares aren't small enough. Anti-aliasing corrects this by adding steps of transparent color near the edge to create the illusion of a smooth surface. Here's a [diagram]( URL_0 ) I made to show you with and without anti-aliasing.",
"Followup question: ELI5 Anisotropic Filtering? I mean, I know what it does (make surfaces you look at a small angle be less blurry), but my question is, why are they blurry to begin with and require extra filtering, if the same surface looks non-blurry if viewed at a direct angle."
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"https://i.kinja-img.com/gawker-media/image/upload/t_original/18j12dtou8x64jpg.jpg",
"https://people.cs.clemson.edu/~tadavis/cs809/aa/aliasing2.png"
],
[
"http://i.imgur.com/p9DRVfj.jpg"
],
[]
]
} | [
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|
659prn | Why can't we create infinite energy with something like this? | Repost | explainlikeimfive | {
"a_id": [
"dg8kpuh"
],
"text": [
"This is called a perpetual motion machine, where the energy you give in is less than the energy the machine gives out. I'm too inexperienced to answer this, but [this video by Tom Scott]( URL_0 ) debunks it and it features your machine (well a variant of it) also!"
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|
65apmw | why atomic bombs make mushroom clouds | Repost | explainlikeimfive | {
"a_id": [
"dg8stpq",
"dg8t15q"
],
"text": [
"It's not just atomic bombs that produce these. Other bombs do as well, just to a smaller extent. It occurs because the core or center of the explosion has a very high heat intensity. As the heat rises it picks up debris and carries it into the air. As the hot air cools it begins to dissipate creating the mushroom effect.",
"Energy release - > big boom fireball - > hot hot - > expands, starts to rise - > creates vacuum - > more air come in - > they rise too - > keep rising until the air on the top is like \"you shall not pass\" - > so the boop shape on the top"
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|
65b9pl | Why does your mouth water before you throw up? | Repost | explainlikeimfive | {
"a_id": [
"dg8wlzq"
],
"text": [
"It's a reflex to protect your mouth. Vomit is very acidic and can cause damage to your teeth and the soft tissue in your mouth (and esophagus too). Healthy saliva is neutral (neither acidic or basic) so it helps buffer the acid in vomit. By /u/thejennadaisy URL_0"
],
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"https://www.reddit.com/r/explainlikeimfive/comments/37stwa/eli5_why_does_my_mouth_water_before_i_throw_up/"
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|
65bwma | Out of all the human beings, living and dead, why in this particular body did I have my consciousness? | Repost | explainlikeimfive | {
"a_id": [
"dg90k30"
],
"text": [
"Well, you had to turn into someone. Turns out you turned into you. It's not that YOU were predetermined to be, it is not that you were before or will be after. It is simply because your body has a brain and that brain experiences consciousness and that consciousness happens to be you. Every person has to be someone."
],
"score": [
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|
65c5p2 | why do hackers want to use linux os even though it's easier to use windows or mac OS? | Repost | explainlikeimfive | {
"a_id": [
"dg922zu",
"dg92d42"
],
"text": [
"Once they get through the learning curve it is easier to use linux. Besides, linux is free. The other two will cost eventually.",
"Linux is generally far more customisable and it's far easier to change things, test out ideas, etc. Also you're less likely to get viruses."
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|
65dhh5 | Why does pulling a ribbon across the edge of a pair of scissors cause the ribbon to be curled? | Repost | explainlikeimfive | {
"a_id": [
"dg9cqyg"
],
"text": [
"When you run the edge of the blade of the scissor over the ribbon, you break the ribbon's structure a little causing one side to be stronger than the other. The stronger side curls the weaker side inward creating the curls."
],
"score": [
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|
65ej9i | How do people figure out what colors to use when coloring an old black and white photo? | Repost | explainlikeimfive | {
"a_id": [
"dg9mnc3",
"dg9p24u"
],
"text": [
"\"Black\" and \"white\" are actually a ton of different shades of grey. If you know the method the picture was taken with and how it converts visible light into something that can be put onto film in greyscale, you can tell with a pretty high degree of accuracy which shade of grey corresponds to which visible light color.",
"Historical perspective, contextual clues, hues and saturations, going with \"expected colors\". The sky is blue, the grass is green, cement is gray. Certain militaries wore certain colors, we have their uniforms today. Once you get through the \"basics\" and what we expect to see, you have quite a bit of info there. Then the other clues can help fill that in. All the colors may not be perfect, but there is still plenty of information in a photo to get buy and colorize it."
],
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|
65fe4x | Pee shivers | Repost | explainlikeimfive | {
"a_id": [
"dg9vfq5"
],
"text": [
"No one can explain this like you are five because this is an open, unanswered scientific question. Some people believe that your body temperature drops when you expel warm liquid, which is contradicted by the fact that you don't experience the same thing when you vomit, shit or donate blood. (Leaving out the Oxford comma for the fun implications). The most scientific explanation that I found had to do with the idea that when you switch from continence mode to free flowing, there is a switchover from sympathetic to parasympathetic nervous system activation and somehow this switchover causes the shivering. Seriously, though, if you answer this question, you're probably a candidate for the igNobel."
],
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|
65fs5q | long division. i'm now 30 nobody has ever been able to explain it to me. also long multiplication | Repost | explainlikeimfive | {
"a_id": [
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"text": [
"Let's say you have 573.5 and want to divide it by 25. First, you know 25•**2**=50, so 25•20=500. That leaves 73.5 left over. Now 25•3=75, so close, but a little too high, so we know it has to be between 2-3. 25•**2**=50 - > 73.5-50 = 23.5 Now, 23.5 is a bit less than 25, so we are gonna deal with decimals. To make things easier, let's times it by 10, making it thus 235. If we had to guess, 25•**9** should get us pretty close, it actually gives us 225. Now we have 10 left (actually 1 because we timed by by 10). Now, 10 is less than 25, so let's times it by 10 again (making it now times 100), giving us 100. This should be easy, 25•**4**=100. **Answer:** 22.94 In long division notation, the process should look like this: 2 ————————— 25| 573.5 -500 ——————— 73.5 —————— 22 ————————— 25| 573.5 -500 ———————— 73.5 -50 ———————— 23.5 —————— 22.9 ————————— 25| 573.5 -500 ———————— 73.5 -50 ———————— 23.5 -22.5 ———————— 1.0 —————— 22.94 ————————— 25| 573.5 -500 ———————— 73.5 -50 ———————— 23.5 -22.5 ———————— 1.0 -1.0 ———————— 0 Obviously you this is all a single workout, but I had to show the process in text. For even better visualization: 20.000 ————————— 25| 573.5 -500 ——————— 73.5 —————— 22.000 ————————— 25| 573.5 -500 ———————— 73.5 -50 ———————— 23.5 —————— 22.900 ————————— 25| 573.5 -500 ———————— 73.5 -50 ———————— 23.5 -22.5 ———————— 1.0 —————— 22.940 ————————— 25| 573.5 -500 ———————— 73.5 -50 ———————— 23.5 -22.5 ———————— 1.0 -1.0 ———————— 0"
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|
65hc8h | Why do guys get post jerk off guilt syndrome? | Repost | explainlikeimfive | {
"a_id": [
"dgaa9wg",
"dgaal56"
],
"text": [
"Post-orgasm your body quickly loses dopamine (chemicals which make you feel good which you get during orgasm) as it returns to its normal state. This quick loss of dopamine makes you feel a lot less happy than you were a few seconds ago, making you feel sad or guilty.",
"Sorry I can't help but I find this weird. Is it normal to have post jerk off guilt? I don't think I've ever had it."
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65if0u | How binary code works? | Repost | explainlikeimfive | {
"a_id": [
"dgair4m",
"dgal1lx"
],
"text": [
"Binary code is just another way to count. Instead having 10 digits, you only have two. In the 10 digit system, every digit to the left is the digit times 10^n (where n is the number of digits to the right, starting at 0). So the decimal number 4711 is basically 1 * 10^0 + 1 * 10^1 + 7 * 10^2 + 4 * 10^3 = 1 + 10 + 700 + 4000 = 4711. The binary system shifts everything times 2^n, so 1011 = 1 * 2^0 + 1 * 2^1 + 1 * 2^3 = 1 + 2 + 8 = 11. You can tell a system (like a computer) to interpret certain combinations of 0 and 1 as a code. For example, ASCII (the first usable text interpretation code) is a 7-digit binary code where every combination is one symbol (printable and non-printable), resulting in 128 possible symbols. For example, the ASCII code 1000001 is 1 + 64 = 65 in decimal and represents the symbol 'A'.",
"I'm currently a Computer Science major, and Computer Organization was my most recent course. Binary inside computers is like math with different rules. We manipulate the properties of it to do very complicated things. ~**The basics of binary:** Binary is, at its heart, a different counting base. Normal people count with Base10, where each place (ones, tens, hundreds) is simply a number multiplied by its base...Ten to a power. Base10 gets its name from having ten digits: 0,1,2,3,4,5,6,7,8,9. How Base10 works: 534 = 4x10^0 + 3x10^1 + 5x10^2. Binary, instead of ten numbers, works with two: 0 and 1. So the binary number 1111 isn't one thousand one hundred and eleven in binary. It is: 1111 = 1x2^0 + 1x2^1 + 1x2^2 + 1x2^3 1 + 2 + 4 + 8 = 15 This is how we count in binary. The whole power thing gets complex, so you usually pick up the powers of two. From right to left, you can label the bits 1, 2, 4, 8, 16, 32, 64, 128, 256.....Etc etc etc if that helps. ~**The Intermediate of Binary** So, now we have a grasp of WHAT a binary number is: it's just a number, represented in Base2 instead of Base10. How can we manipulate it? Well, arithmetic is a nice thing to do! Let's cover the basics. Adding 2 binary numbers: 1010 ... AKA Ten in Base10 0011 ... AKA Three in Base10 --------- 1101 ... AKA Thirteen in Base10 The numbers get added just like you remember from Base10. 0+0=0. 0+1=1. 1+0=1. 1+1=0 carry the 1. Multiplying 2 binary numbers: For the sake of staying near ELI5, we're going to do the easy multiplication: Multiplying something by 2, 4, 8, etc. Think of what happens when you multiply by ten in Base10. 6 becomes 60. 745 becomes 7450. Everything just shifts left one. Binary is no different when you multiply by 2. 01001 -- > 10010 Multiply by 4? Everything shifts twice. 001101 -- > 110100 ~**The Harder Levels of Binary** So now we know that Binary is a number system...And it has mathematical operations. However...Binary is also conveniently an easy way to control switches. One and Zero can count....Or One and Zero can be On and Off....Or One and Zero can be both. If I have 4 LEDs (lights) in a row on a breadboard, I can describe their states in binary. 1 0 0 1 On off off on. Computers use binary in this way as well. It can count, it can catalog, and it can serve as simple on/off. It will use a certain string of binary (example, 0111) sent to a certain place at a certain time to signal that something is being pulled from RAM. It will then use binary to define the address (think of how we define RAM. 512KB? That's stored in binary. See how it's a convenient 2-multiple?). The value stored at that address is a binary number. *How* this binary string is used depends entirely on context. You could be adding. You could be controlling switches. You could just be feeding into a complicated logic diagram of ANDs, ORs, XORs. It all depends on the context. As far as what binary physically does inside a computer....It just activates transistors - microscopic switches. It's boring and repetitive on an eli5 level..But oh so fascinating on a collegiate level. If you want to learn more about that: find an online Computer Organization course. It will teach you everything you want to know about computer basics. Binary logic - > Logic gates - > Solid State Machines - > Processors - > Memory (to include building memory gates) - > Registers - > etc. ~**Some fun facts:** 1 binary digit is a bit. 8 binary digits are a byte. 4 binary digits are a nibble. Hexadecimal numbers are just a bunch of nibbles (2^4 = 16). When you see a MAC address, an ugly default router password, or an IPV6 address, it's just a shorthand, eye-friendly way of showing you a humongous binary number (4 bits for every character)."
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65j997 | How do glass and other transparent materials work on a molecular level? Do they have more space in between molecules? Does the light interact a lot less with their molecules? How does the light come through where in other materials the light is absorbed? | Repost | explainlikeimfive | {
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"text": [
"Glass does absorb light, but not in the visible spectrum. Molecules have molecular energy levels for their electrons (and atoms also have atomic energy levels the same way). When they absorb light, the energy of the light matches the energy difference between the energy levels, and an electron is promoted to a higher energy level. It just so happens that typically, the molecules in glass (mostly SiO2) don't have a difference in energy levels corresponding to the energy of visible light. They do happen to have a difference in energy level that corresponds to light in the UV spectrum, hence UV light does not pass through normal glass very easily (unless it's pure SiO2). This also means you're unlikely to get a sunburn in your car with the windows up. It also happens that the glass molecules are generally not the right size or shape to scatter visible light either very much. However there is some light reflected from the surface because glass has a different refractive index than air (ie. light travels slower through glass). At any boundary where there is a refractive index change, some light will usually reflect (see the Fresnel Equations). Hence if the surface of the glass is not smooth, it will reflect light in many directions, and it will effectively scatter light at the surface. EDIT: like Mariofosheezy pointed out, also remember that most matter is not very dense, most of the volume is made up the \"electron clouds\" hence if the molecular orbitals of the glass don't interact much with the light, then it is basically passing though 99.9% empty space as far as it's concerned. EDIT2: It get's more complicated than this. Many other materials have other properties that make it so that visible light can't really pass through. Some have very good absorbance in the visible spectrum, others have very densely packed molecules/atoms that attenuate light very rapidly, etc.",
"The interactivity, attenuation, and refractive index of a material varies with the frequency/energy of the emr. Glass is mostly non interactive with visible light but will usually absorb infrared and ultraviolet light. Your cellphone still works indoors even though you can't see through walls. [Here is a stove top that is opaque to visible light but transparent to an infrared camera]( URL_0 ) A photon needs to be able to excite a molecule in order for it to be absorbed so it would need to have an energy near the band gap of its electron's next highest level or able to rotationally excite the molecule. Density matters some but only as it places more matter for light to travel through and the same effect could be achieved with a thicker window of less dense material.",
"Essentially the answer is one of your suggestions. The light interacts less with the molecules. Detail below: First, we need to understand that light is weird. It's neither strictly a wave, nor a particle. Under certain metrics it behaves like one or the other. This is called the \"wave-particle duality\". When referring to light when it behaves like a particle we call it a photon. Next, light of different colours has different wavelengths. Each individual photon has a specific wavelength, and light is essentially made up of a constant stream of photons. Smaller wavelengths are more energetic (this may seem counterintuitive when first introduced to the concept but you can think of a smaller wavelengths as vibrating faster). Blue has a smaller wavelength than red, thereby giving it more energy per photon. Similarly, ultraviolet has more energy then blue. The spectrum of light ranges from radio waves (1km+) to gamma rays (1nm-). The smallest wavelengths are incredibly energetic, enough to break apart chemical bonds and can even cause damage to a person's DNA. Visible light is approximately in the 500-1000nm range. When an opaque object is struck by these photons, the energy is absorbed. For each photon absorbed, a corresponding electron is bumped up to a higher energy state. The \"space\" where that electron used to \"fill\" is called a hole. These holes generally want to be filled again with electrons. After a very brief delay (incredibly brief for almost all materials), the electrons that are energized \"fall\" back into the hole. When this happens, they are no longer in a high energy state and need to expel the excess energy that they absorbed earlier. Depending on from what energy level they fell from, different amounts of energy needs to be expelled. This energy is released as new photon. However, the electrons don't fall back down in one step. There are only certain ranges of energy levels that electrons are allowed to be in (depending on atomic/crystal structures). This is different for every material. The electrons falls back down in a few steps and emits a photon for each jump down. For many objects, the energy between these gaps results in photons that have an energy level that puts them in the visible spectrum. Some have multiple jumps in the visible spectrum, and to the human eye they'll appear white or brown or some other \"non-rainbow\" colour. Now let's look at transparent objects. In glass (SiO), the bands of allowable energies that the electrons can have is quite limited. When a photon strikes the glass, it wants to give it's energy to an electron so it can jump up in energy levels. However, since the gap between allowable electron energies is so large, there would be nowhere for such an energized electron to go. Thus, the photon does not get absorbed and remains the same colour as it entered the glass and passes through unchanged in wavelength. (A percentage of photons may change direction due to reflection/refraction, but the colour remains the same) Photons that have a higher energy level may be able to overcome this bandgap. They will be absorbed and re-emit new photons just like if the glass were opaque. However, this isn't within the visible spectrum and can't be seen. Sidenote: The energy absorbed when the photon strikes an object doesn't have to ALL be re-released as new photons. It can also create \"phonons\" which are essentially molecular vibrations that increase the thermal energy (heat) of the object. That's why objects that don't re-emit the light (appears black to the human eye) get hotter when exposed to light.",
"Professor Moriarty explains it well in [this]( URL_0 ) video. He is a photon trying to get through his office, there are lots of ball pit balls on the floor (atoms). He wants to move them onto the shelf. If he manages to move the balls he uses his energy to move them off the floor and doesn't get through the room. If the shelf is too high to reach (the energy gap is too great) he doesn't move any balls and continues through the room and gets out the other side.",
"It's best to think of light in terms of waves for this. If ray of light hits a molecule, it will absorb part of it and emit another ray of light in the same direction as it usually can't absorb it. However the time it takes for the molecule to re-emit the wave varies. If a molecule re-emits the wave fast enough, it will appear that nothing has changed, and the light just passed through. If a molecule is too slow to emit, the new wave might vibrate in the opposite direction to the old wave, hence reducing the amount of light getting through. If the material is thick enough, no light will pass through at all, such as in wood."
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65lcda | If two or more items are plural, and one item is singular, why is zero items plural? | Repost | explainlikeimfive | {
"a_id": [
"dgb5q8v"
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"text": [
"Because singular is only one item. Zero isn't one, therefore it is plural. It may be intuitive to think of plural as being \"more than one\" but it isn't like that."
],
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|
65ls1n | When someone is given the death penalty, why are they on death row for so long? | Repost | explainlikeimfive | {
"a_id": [
"dgb9gz3",
"dgb9g1l",
"dgbwjzb"
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"text": [
"There's an appeals process that has to be followed, and that can take years because the courts are really very busy. Then there's the fact that issuing stays of execution is a very easy, low-cost way for governors to earn brownie points with more liberal constituencies who understand how many innocent men have danced the sisal two-step because the State was in a rush to punish someone.",
"There's a line for appeals, they have the right to challenge the ruling and exhaust their options. Then it comes down to the state and its resources; timing the executions. It can take a very long time to do all of this, years and years.",
"As NarnBatSquad and HappyShrapnel said, it all comes down to resources, legal avenues of appeal, and the long, long list of people that are already there. Many that are on 'death row' are actually awaiting a new trial or hearing; one of the West Memphis Three was on the Last Mile for 18 years, fighting for a new hearing, because his initial conviction was pretty much a show trial. Incidentally, while the 'last meal' for a death row inmate is simply a custom, and not a requirement or obligation, most prisons have stopped following the tradition because inmates regularly abuse the 'last meal' custom by ordering huge amounts of food that they can't possibly finish."
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|
65mvpz | What is dust? | Repost | explainlikeimfive | {
"a_id": [
"dgbjdmq"
],
"text": [
"Skin particles, human/animal fibers, minerals of various types, pollen, etc. The type of dust you encounter/inhale depends on the type of environment you're in. For example, you'll obviously inhale more paper fibers in a carpenters workshop than in a kitchen or some other random area."
],
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|
65oled | Dark Matter | Repost | explainlikeimfive | {
"a_id": [
"dgbxlbp"
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"text": [
"The laws of gravity are exceptionally well understood. They tell us exactly how an object of some mass should move around. On a cosmic scale we use Einstein's general theory of relativity to do this. All the major predictions of general relativity have been shown to be correct, so we are exceptionally confident that this is the right theory of gravity for our Universe. That being said, when we look at galaxies, we find that they don't move in accordance with our predictions from the law of gravity, based on all the mass we can see in them. We find that they rotate far too fast - if there was only the mass we could see, they should be breaking apart, yet they are still held together. Since we're exceptionally confident that our description of gravity is correct, it's only logical to assume that there must be some unseen mass. We call this dark matter. What is dark matter made of? We don't know. Leading theories suggest a new type of particle, that interacts via gravity and the weak force but not electromagnetism (which is why we can't see it). We call these hypothetical particles weakly-interacting massive particles, or WIMPs. Experiments are underway to try to detect them but so far we haven't found any. Particle theorists are also coming up with theories to predict what these new particles should be, but they are also having trouble. There are other ideas as to what dark matter could be, and some mavericks do suggest that our theory of gravity may be wrong, which is possible but unlikely given it's success in other areas."
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|
65p4p6 | Why do we seem to look different in mirrors compared to photos and such? | Repost | explainlikeimfive | {
"a_id": [
"dgc1kms"
],
"text": [
"because mirror image is flipped (mirrored), in other words mirror image is just how you see yourself (your perspective of 'you'). Whereas photos aren't flipped and display yourself as it is, in other words, you in a photo is how other people see you."
],
"score": [
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|
65pmyr | Muscle Growth | Repost | explainlikeimfive | {
"a_id": [
"dgc5hgd"
],
"text": [
"When you lift weights you're actually creating tears in the muscle tissue. The tears heal and create scar tissue on the muscles. That scar tissue is what causes muscles to grow."
],
"score": [
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|
65qyii | How did different languages start and how did people who first encountered new civilizations learn the languages? | Repost | explainlikeimfive | {
"a_id": [
"dgch22x",
"dgcgy9b"
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"text": [
"The relationships are quite complicated. [This great graphic]( URL_0 ) goes a good job of showing the connections.",
"Languages started through basic communication. Arbitrary sounds that related to a specific thing. Those naturally evolve over time and become more efficient and complicated at the same time. As for translation, they would have to start with common ground. Say you pick up a rock and say \"rock.\" You could establish how to say rock in both languages as long as the other person realizes you mean to communicate, which is pretty easy to determine. Have you ever tried to communicate with someone who didnt speak your language? Its the same process."
],
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"http://mentalfloss.com/article/59665/feast-your-eyes-beautiful-linguistic-family-tree"
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|
65r28y | What do the bunny and eggs have to do with the resurrection of Jesus Christ? | Repost | explainlikeimfive | {
"a_id": [
"dgchthn",
"dgchre4"
],
"text": [
"Nothing. Not even as much as Santa and Christmas. Spring fertility celebrations go way back into pagan days, and the new religions tried to fold in the things people enjoyed - it's good marketing.",
"They are all pagan rituals adapted to Christian mythos to increase the amount of believers."
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|
65rong | How do amplifiers work? | Repost | explainlikeimfive | {
"a_id": [
"dgcodlg",
"dgcopmy"
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"text": [
"This explanation depends somewhat on knowing basic electronics concepts. A transistor is a unit with 3 connections only. One is a pathway for current out of the transistor, usually ground. One is for controlling current. The last one is connected to a higher voltage, which is the source for current. If you expose the control to a changing signal, you'll get a changing amount of current flowing through the transistor. Technically, a certain type of amplification is already occurring. But we usually start with voltage and want to end with voltage. One way to achieve this is for the transistor to draw its current through a resistor, which will produce a changing voltage thanks to the fundamental relationship between current and voltage passing through a resistor. The problem is, this is a changing amount of current flowing in one direction. We usually want current flowing in both directions, alternately, for a signal like music playing through headphones. In short, you use an assortment of transistors passing electricity in one direction only *within each one*, but in opposite directions to other ones in the circuit. It takes some complex and clever design, but you get it balanced right and you can create current flow in both directions, just like your original source. A helpful tool is that you can make \"backwards\" transistors that control flow with a controlling signal that is compared to the high voltage, not low. Going into much more detail gets into \"take a class\" or \"read an intro to EE\" textbook levels of explanation, but that's the basic idea. Transistors take small signals and make them big. Hook them together right and you can get them to take the signal you need to use and produce a bigger one of the right type.",
"In general terms, an amplifier is a system where a small change in the input causes a big change in the resulted output. For an analogy, think about the flow of the river through a dam. When the dam is closed no water can pass through, but if we raise the damn just a few centimeters, a large amount of water from the river behind him will start to rush in. The electronic vacuum tube or the solid-state transistors in your amplifier are working in a similar fashion. Without getting into the physics behind their operation, you can think of an amplifier as a set of vacuum tubes or a set of transistors, acting as dams and directing the flow of electricity from the main power supply to your headphones or speakers. A small change of current at the base of the transistor will result in a big change of the current that pass through him from the supply to the output."
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65rxjw | Why is it that you have to look right next or past an object in the dark to see it rather then just looking at it directly? | Repost | explainlikeimfive | {
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"This is a result of the structure of receptors in your eye. The cones in the center are more sensitive to color and details, while the rods which are used for peripheral vision are more sensitive to light and movement. So looking sideways allows you to observe the darker object around you.",
"Rods and cones :D Rods are much more sensitive to low light than cones are so most (all?) low light vision is with rods. There are far fewer rods at the center of your vision than elsewhere on the retina so you see far less low level light there. URL_0 > \"If you see a dim star in your peripheral vision, it may disappear when you look at it directly since you are then moving the image onto the cone-rich fovea region which is less light sensitive. You can detect motion better with your peripheral vision, since it is primarily rod vision.\""
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65tltt | Brexit | Repost | explainlikeimfive | {
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"text": [
"EUROPE! Post WWII they all play nice and friendly. They form the European Union. ([And the Eurozone, Council of Europe, Schenzen zone, OMG SO MANY AGREEMENTS]( URL_0 )) Anyway, they're friends, they come together, they trade, travel, and all play along. Like how the states in the USA play nice... but without the big giant federal government enforcing it. A group of people in the UK don't like the how they're getting treated, don't want to play nice, and want to leave the EU. To appease them, Prime Minister David Cameron says they'll have a referendum on the matter in a few years. It's a special vote. Like, \"hey people, should we leave the EU\". People in London, Scotland, and N. Ireland voted to stay part of the EU, the country bumkins voted to leave. They get 51%. Cameron steps down. Theresa May becomes to new Prime Minister (it's like our president). And... it looks like it's happening. A lot of deals are being undone, rules enacted, but at least they never switched to their money to the Euro, so that's not a mess. So... Why did they want to leave the EU? That's a tough one. And you'll get a lot of political opinion that's only marginally associated with the truth on the matter. From both sides sadly. There are parallels between the Brexit vote and the victory of Trump in America. It's the effect of the rise of the [UK Independence Party]( URL_1 ). Both were rural, right-wing, mostly white, somewhat nationalistic, opposed multiculturalism, opposed immigration, and appealed to populism. Oh hey, tax cuts and climate change denial are both in there too. The two movements are quite similar. If you're looking for a \"why\", then pretty much every explanation you've heard for the Trump presidency applies to Brexit too. Something something, populist nationalism, disenfranchised working class, blaming immigrants, fight elitism. I personally blame automation taking away the jobs and growing inequality as seen by the GINI coefficient. But it's a lot easier to get people to vote for you if you have a more familiar scape-goat, and historically everyone hates immigrants. Imagine if Trump got elected as governor to Texas on the platform of separating from the USA. And that was legal and currently in the works. It's a lot like that."
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65ubl2 | Who decides if art is 'good' and what it's worth? | I remember reading a few years ago that a painting of a black dot on a white canvas sold for millions of dollars. Who actually decides if an art piece is actually any good? | Repost | explainlikeimfive | {
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"Usually it's based on the body of work of the artist. For example, by the end of his work life Joan Miró was placing a single stripe of paint on a canvas and these are very prized even though *anybody* could place a stripe of paint on a canvas. Like he'd stare at the canvas for a while and then in one fluid movement put a single stroke down and he'd love it and everyone else would love it. This is because he spent his whole life evolving from being a talented painter that you'd probably call \"normal\" (i.e. he made pretty pictures with paint) to becoming a more and more abstract painter. He kept reducing the complexity of his forms to see how to express emotions and form in an ever increasingly abstract way so that after decades of doing this he had developed a kind of language of form that was uniquely his. So if you're aware of his progression and have an understanding of how to \"read\" his abstraction you can see how his single stripe of paint has meaning and is different and special compared to a stupid stripe of paint that just *anyone* could do.",
"If someone wants it they'll buy it. If someone else wants it more they'll pay more for it. Eventually you've got an expensive work of art. As for why people want it, preferences are impossible to determine across a population.",
"This is what we mean when we say \"market forces\". So there is no single person or organization that decides what is worth what. A thing is worth as much as someone else is willing to pay for it. That dot sold for what it did because someone else was willing to pay that much for it. There is no central authority that sets prices for art. The question is, why would someone pay that much for a dot painting. And the answer is complex. Could be that they really liked the dot and really hated money, but likely not. A better answer is that they felt, given their experience in buying art, that this particular painting by this particular artist was worth that much money. This feeling was based on other paintings by that artist and how much other people have paid for them, along with a general feeling about what the future value of that artist's paintings is going to be. Art has no intrinsic value. Meaning, you can't break it down and sell it for parts. Art is only worth money because other people are willing to pay for it. If people all of a sudden decided that Pasco's paintings were all worthless, you'd not be able to sell them at all. The price of art is 100% based on other people's perceptions."
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65vmxi | Why does netflix drop titles? | Repost | explainlikeimfive | {
"a_id": [
"dgdi0jl"
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"text": [
"Netflix has agreements with content owners that can include specific times when content may be available. Its not always Netflix that decides. They also need a way to drive new subscribers and want to appear that they have things you have not seen yet. There is limited screen real estate on a web page and frankly viewer patience, and they want to keep your interest. Netflix is NOT a library."
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65vssj | Why do some words have silent letters? | Repost | explainlikeimfive | {
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"text": [
"\"Pneumonia\" is spelled that way because it comes from the Greek word \"pneumon\" which means \"lung\" (so \"inflammation of the lungs\"). In Greek, the \"p\" was (and still is) pronounced very clearly. But this cluster of consonants at the beginning of a word is not allowed in the phonology of English -- \"phonology\" being the rules about what sounds a language has and how they can be combined to make words. We can either insert a vowel between the consonants and say \"puh-neumonia\", or we can just not pronounce one of them -- which is what we choose to do. But we have kept the Greek spelling. Spanish-speakers, incidentally, have a similar problem with the consonant clusters \"sp-\" and \"st-\" at the beginning of a word. They find it quite difficult to say the English word \"Spanish\", and in Spanish itself words like \"to study\" become \"estudiar\", with an extra \"e\". French goes one better by then leaving off the \"s\" as well, to make \"étudier\". Another example is a word like \"night\", with a silent \"gh\" in the middle. This is a much older English word, and originally the \"gh\" represented a sound like a rasping or gurgling noise in the back of the mouth. The German language still has this sound (and spells it \"ch\" as in the German for \"night\", \"Nacht\"), but English doesn't any more. However, we haven't bothered to update the spelling."
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65w83z | Why are the planets all on the same plane? | Repost | explainlikeimfive | {
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"dgdmkr9"
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"text": [
"Because the solar system is spinning. Spinning things become flat. Like pizza dough when they throw it in the air."
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65yhqi | Why is it easier to carry a 50kg human than a 50kg dumbbell? | Repost | explainlikeimfive | {
"a_id": [
"dge5rs3"
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"text": [
"There are two parts to this problem. First, the human is larger, so you have more even weight distribution. You also generally carry a human differently from how you carry weights. Second, the human moves and shifts center of mass, which may make it harder to carry a person. The combination of these factors causes the weight carrying experience to be different. Different people may perceive one to be easier than the other or for them to be the same."
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660k65 | What is special relativity, and what does it mean for how we understand the Universe? | Repost | explainlikeimfive | {
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"Do you realize that entire college degrees are spent understanding this topic and its applications?",
"From Maxwell's equations to the Michelson-Morley experiment, the universe seemed to be telling us the speed of light was invariant. While scientists of the time saw this as a failure of the equations and experiments, Einstein recognized it as a confirmation of a fundamental truth of the universe. He accepted the fact that the invariant speed of the universe is defined as a constant c. From this postulate alone, Special Relativity is nearly the entire reformulation of physics to satisfy this postulate. We normally think of time as a parameter and distance as an observation: the position of an object as it moves through space is measured against time. x(t) represents the object's x coordinate at time t. And even then we could have recognized that space doesn't have a very meaningful intuition: depending on the reference frame used, your coordinates could map an object traversing a line or a parabolic path. This made movement a relationship between an object and a rigid body, not really between a natural set of spatial coordinates. Anyways... Depending on your frame of reference, a photon would travel a different path which requires an adjustment in the values of d and t to guarantee the velocity of light remains c. No longer is time simply a parameter, but is now also an observation dependent on the frame of reference used, similar to the previous example used of space. So now we create a new coordinate system that integrates both space and time as a transformation via reference frame to model reality instead of just modeling space."
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660rpg | What is encryption? | Repost | explainlikeimfive | {
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"First off, this isn't mine, source at the bottom. Secondly, imagine that the lockbox is an algorithm. Alice wants to send a private message to Bob, and the only easy way they have to communicate is via postal mail. Unfortunately, Alice is pretty sure that the postman is reading the mail she sends. That makes Alice sad, so she decides to find a way to send messages to Bob without anyone else being able to read them. **Symmetric-Key Encryption** Alice decides to put the message inside a lockbox, then mail the box to Bob. She buys a lockbox and two identical keys to open it. But then she realizes she can’t send the key to open the box to Bob via mail, as the mailman might open that package and take a copy of the key. Instead, Alice arranges to meet Bob at a nearby bar to give him one of the keys. It’s inconvenient, but she only has to do it once. After Alice gets home she uses her key to lock her message into the box. Then she sends the lockbox to Bob. The mailman could look at the outside, or even throw the box away so Bob doesn’t get the message – but there’s no way he can read the message, as he has no way of opening the lockbox. Bob can use his identical key to unlock the lockbox and read the message. This works well, and now that Alice and Bob have identical keys Bob can use the same method to securely reply. Meeting at a bar to exchange keys is inconvenient, though. It gets even more inconvenient when Alice and Bob are on opposite sides of an ocean. **Public-Key Encryption** This time, Alice and Bob don’t ever need to meet. First Bob buys a padlock and matching key. Then Bob mails the (unlocked) padlock to Alice, keeping the key safe. Alice buys a simple lockbox that closes with a padlock, and puts her message in it. Then she locks it with Bob’s padlock, and mails it to Bob. She knows that the mailman can’t read the message, as he has no way of opening the padlock. When Bob receives the lockbox he can open it with his key, and read the message. This only works to send messages in one direction, but Alice could buy a blue padlock and key and mail the padlock to Bob so that he can reply. Or, instead of sending a message in the padlock-secured lockbox, Alice could send Bob one of a pair of identical keys. Then Alice and Bob can send messages back and forth in their symmetric-key lockbox, as they did in the first example. This is how real world public-key encryption is often done. Bob generates a key pair, consisting of his public key (red padlock) and private key (red key). Bob then publishes his public key, and Alice fetches it (Bob mails his padlock to Alice). Alice then generates a temporary symmetric key (the pair of orange keys) and uses Bob’s public key (red padlock) to securely send it to Bob. Bob then uses his private key (red key) to unlock his copy of the symmetric key (orange key). Bob and Alice can then use those symmetric keys to securely send messages back and forth. Each time you click on an SSL link or connect to your mailserver this story plays out. Your browser or mail client plays the part of Alice and the server you’re connecting to plays Bob [source]( URL_0 )",
"Complex math done to scramble computer information. The only way to decode it is with a special secret password (that you give to only special people you want to see the info) that would takes hundreds of years to guess even with the fastest computers. You cant see the computer info without the special password.",
"Shortest possible answer: Using some sort of \"key\" to scramble a message so that it is unreadable to anyone without knowledge of the key. Simple +1 cipher. You send me the message \"Hello\". You use a +1 key, meaning A becomes B. B becomes C. C becomes D. etc. H=I E=F L=M L=M O=P. The message \"IFMMP\" is useless to anyone who doesn't know how to unscramble it. Obviously, +1 would be way too easy to figure out. That's why effective encryption uses a very complex math process and key. Now that most information is \"digital\" (can be represented on a computer with numerical values) complex math works very well for scrambling the data.",
"Imagine I have a message I want to send, but it's not something I want everybody to read. I can send it \"in code\" so it seems like gibberish to anyone else. That's basically what encryption is. I could for instance just move every letter up one space in the alphabet, so A becomes B, B becomes C, and so on. So the message \"I like pineapple on my pizza\" becomes \"J mjlf qjofbqqmf po nz qjaab\". Not making much sense, it it? But if you *know* what I did, you can just reverse it and read the message. So I make sure I only tell the people I want to be able to read that message, and I won't have to worry about anyone else reading it. In this case it's \"symmetric encryption\", because anyone who knows how the message was encrypted can also decrypt it. There's another form of encryption called \"asymmetric encryption\", which is essentially the same, except you need to use one specific way to encrypt your message, and then you can only use a *different* method to decrypt it again. You could also compare it a bit like sending your message in a lockbox. In asymmetric encryption, you give out padlocks and keys to everyone who asks for them, but those keys can only *lock* the padlocks. Only a special key can unlock it, and you're the only one with that key. In symmetric encryption you have to be very careful who you give the keys to, because anyone with a key can open any lockbox sent to or from you. Now, in computer terms, this is quite common, for instance in web traffic. You've probably heard of SSL at some point. SSL uses asymmetric encryption - so you connect to a server (which is really just the computer you're talking to) and it gives you a *public key* (the one that can only lock the box). You encrypt your messages with the public key, and because only the server you're talking to has the private key, you can be sure that nobody listening in on what you're sending can read what you send. The server does the same thing the other way around - you give the server *your* public key, which the server then uses to encrypt messages sent back to you, so only you can read them."
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669tic | Why do we have to turn off our cellphones during flights? | Repost | explainlikeimfive | {
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"text": [
"Because takeoff and landing are by far the most dangerous parts of any flight and are therefore the bits where you most need to be listening to the flight crew in case of emergency and not distracted by your phone. If they were actually dangerous to the aircraft, they wouldn't let you have them at all.",
"Air flight control and commercial ISP's run on different frequencies, so no. There is no interference. But its the better safe than sorry principle. There are no guarantees that all wireless devices are up to regulation standard."
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66cj87 | What is cultural appropriation and why is it a bad thing? | Repost | explainlikeimfive | {
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"It's basically when a majority group latches onto the trends started by a minority group. It's a pretty loaded term, and often taken to extremes to mean that one idea or custom belongs to that group and no one else can have it, when in a society with free trade and exchange of ideas, it will be inevitable. As with many things, the context of why someone is using those cultural items matters more than them just simply using them. If Youre dressing in blackface, that's bad. If you like native americans and want to own a dream catcher, nothing wrong with that.",
"Simplest terms. Do you share the culture of the one you are representing it? Are you attending a cultural event that requires this garb? Do you understand the cultural significance of this garb, and are you wearing it appropriately? This is not an issue of opinion. Appropriation of culture is when one individual attempts to use a culture as a fashion statement, and not for it's intended use. Let me add on to this using examples: A white man has a Native American dream catcher in their car as a mirror hang: appropriation A white man has a Native American dream catcher in a window or door way: not appropriation. A company sells kimono's as a Halloween costume: can you guess? It shouldn't be a guess because it's not a costume. Anyone can partake in any culture. That's not appropriation, that's appreciation. It's when someone decides it's use outside of the cultural norm."
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66cnrt | How can ~90% of the web be on the dark/deep web when the majority of the users on the surface web don't even know what it is? | Repost | explainlikeimfive | {
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"This is what happens when the mainstream media and its useful idiots make shit up, publish it, only to have it gobbled up, misinterpreted, and regurgitated by other useful idiots. The surface web, deep web, and dark web are all manufactured concepts that are almost entirely meaningless to any computer academic. Summed up briefly, they can be roughly defined as follows: Surface web: The surface web consists of web pages that are accessible or discoverable through search engines. Deep web: The deep web consists of content that is not accessible or discoverable through search engines, often requiring extensive navigation or even authentication. Most \"deep web\" content is obvious, such as password-protected services; for example, the contents of your GMail account will not be found on an anonymously accessible search engine. Dark web / Dark net: The dark web consists of content that is accessible only through the use of special software, most notably Tor, I2P, and Freenet. The problem: It's often repeated that 90% of web content is found on the deep web or dark web. However, a \"web page\" is entirely impossible to quantify, it's not a metric in any sane sense. Accordingly, it's impossible to evaluate objectively. The static web page of the 1990s and early 2000s is gone, now everything is dynamic. To make matters worse, most \"deep web\" content isn't actually deep at all, it's expressly excluded from search indexing at the website maintainer's request because it's not search worthy. However, this alone does not mean that it is not indirectly accessible through a search engine by way of another resource that incorporates it. To make matters worse, how big is a piece of \"web content\"? Are the petabytes of Youtube videos considered to be part of the surface web? It would have been more appropriate to say that there is a great deal more content on the internet than is available through most search engines; this maintains the largely subjective and highly imprecise and non-scientific matter of trying to quantify and classify the internet.",
"It's important to understand that the **deep web** should not be confused with the **dark net**. The **deep web** is simply composed of all the web pages on the Internet not typically indexed by search engines like Google. This includes things like password-protected pages, dynamic pages, or encrypted networks. You visit these pages all the time, usually through means of starting from a page found on the surface web and navigating further through the website. What you're likely thinking of is the **dark net**, which is a subset of the deep web accessible only through special means, the most well-known of which is likely the TOR network. It is here that you're more likely (but not always) to find \"shady\" transactions and media content. So, to answer your question, most people actually know *what* the deep web is but simply don't know *it's called.*",
"The majority of the internet is on the \"deep web\" because it is simply not indexed. This is things like user profiles on private web sites, all pages behind paywalls, and so on. Basically anything that requires you to log in, since most of those pages won't be indexed. The \"dark web\" is a very small part of the internet that also happens to be not indexed (so it's part of the deep web).",
"Ok, the deep web isn't the dark net. How large a portion of the Internet is the dark net? Also the claim that most of the Internet is porn and most people using the Internet are watching porn (which I've seen claimed plenty of times), how accurate is that?",
"Surface web/clearnet: google and anything you can find by using search engines. This accounts for the majority of sites and content (youtube, tv shows, pictures, ect). Deep web: Places you can't get to using a search engine. These include everything from email to databases to online libraries. For example, I can't access my Uni's online records or ebook library without a special login. Dark web: Refers to content accessible only through a tor browser in order to provide security and anonymity. An example of a dark web site is: URL_1 This is a mirror of an informative site ( URL_0 ), if you were to click on it in firefox, you'd get an error message because the address links to a 'darknet' page.",
"The deep Web is simply stuff that is Web hosted but not publically available through url links. So, for a super simplified example companies use intranets all the time for document and data storage. My lab, for example, has tens of terabytes of data from the last 2 years available for our collaborators to access. That's more data than I have probably downloaded personally in the last 20 years of using the Web. But it's not publically archived or accessible, so is classed as deep web.",
"well % of something does not mean % of the people who see it. my apple is 95% white, but the vast majority of people seeing it only saw the red part. theres also the black seeds, but thats the bad part and we dont really go there because thats a bit more taboo/illegal. you definitely cant see the seeds by just looking at the skin though",
"When that stat was developed, a healthy portion of the 90% of the data was the [NOAA's climate database]( URL_0 ) and several other large, public data sets. Which search engines pointed to but didn't index the data stored there.",
"The deep web is just anything that is not indexed by a search engine. If you have web-based email, every single part of that is \"deep.\" If you've gone to a site like amazon and bought something, the page with the purchase information is deep. As is any page that has content change based on if you are logged in. Dynamically generated pages like these far exceed the number of static web pages you could normally find, and so they make up the majority of the web. Even though a lot of them only exist temporarily.",
"What are some of the \"Must see\" or must visit sites on TOR? I've had an onion browser on my iPhone for a long time but I hardly ever use it. It's a paid for one so it's updated regularly.",
"ELI5 how do people access the dark web? Do they need a certain computer? Router? Edit: seems I only need the URL to a dark site, hook ya boy up! Unless it's illegal, then hook a friend of mine up!",
"My website is part of the deep web, because I told robots to stay away. I use it for testing, and I don't want it indexed.",
"It's like when you live in a big city and decide to shop at Walmart and target for everything when there are hundreds of smaller businesses you might have never heard of that you could go get all that stuff from instead.",
"There's no correlation. The underlying layers are like outdated infrastructure that nobody uses. The criminal element we're all enchanted with is a small portion of that. Imagine subway tunnels being successively built on top of each other due to unstable ground, rising water levels, or whatever. Once you've built the 4th tunnel, 75% of \"the subway system\" is unused. It still exists, and you might even have a few people in scuba gear doing some shady shit down there.",
"The Deep web is mostly just personal data and databases and stuff. And the darknet is a small part of the deep web. Sometimes, people separate the terms. The point is... Amazon, Google, Walmart, all those sites have lots of data. They have their own internal systems for managing data. And no one gets to browse this stuff, except for them. Now, granted, each company individually is not that much, but all of the companies together have a lot of data! That's the deep web. The non-indexable stuff. The private stuff. The dark web is TOR sites and doesn't take up that much storage. Compared, the deep web is huge and includes *all* non-public network-accessed pages. Some consider deep web to include darknet sites, and others don't. Really just arguing semantics at that point IMO."
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66ds5x | What prevents banks and other institutions that hold money electronically from just digitally changing the amount that they have? | Repost | explainlikeimfive | {
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"There are audit trails. Every time money is added to an account, there **must** be a corresponding removal from another account somewhere, and every step has to be recorded. If government auditors find that there was fraud committed, and money just materialized out of nowhere, someone is going to federal prison for a very long time.",
"banks don't actually hold money electronically in that sense. what they have is claims on other entities. for example, if they've given lons, they hve a right to repayment. if they change the amount loaned on their books, naturally the borrower will notice and sue them. if you're thinking of the \"spare cash\" a bank has, well, it has to keep it with some other bank, right? that's usually the central bank, which generally doubles as the regulator. and if you pretend you have more money deposited with it than you do, well, that'll go about as well as you pretending you're a millionaire.",
"The electronic banking record isn't a record of \"amount that they have\", but a record of how much money they owe to/from somebody. You can calculate the capital that a bank owns by subtracting the claims others have on the bank (i.e. customer deposits) from claims the bank has (i.e. loans, funds held with other institutions, bonds), but it's a secondary metric that depends on the actual claims that each can be verified separately. Changing the record doesn't change how much money you owe, it just means that you have a wrong record - which will be (generally) noticed by the other party. I.e. if a bank would set your account balance to zero and refuse to correct it, you'd go to a (small claims?) court and get your money anyway. It's a bit misleading to think of electronic banking as electronic cash (this analogy might be more suitable for Bitcoin), they're really electronic I-owe-you's exchanged all around.",
"They are audited by a 3rd party. If they tried to make something appear from nowhere, there would be a discrepancy in the records. Penalties could range from huge fines to criminal charges."
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66fv4q | If laws over marijuana use is such a concern-how can people (Willie Nelson, Woody Harrelson, Seth Rogen, etc) flaunt such a lifestyle seemingly without consequence? | Repost | explainlikeimfive | {
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"Possession is what is illegal. Snoop was arrested here in Texas after they pulled over his tour bus.",
"They have enough money that any punishment the court could possibly levy against them can be bargained away. With money, either given directly to the court system or donated to law enforcement.",
"Being caught with marijuana is only an issue for people that can't afford to get caught with marijuana. Edit: in states where it's still an issue."
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66ha0v | Why can't video game graphics be as realistic as movie CGI or the in-game cutscenes? | Repost | explainlikeimfive | {
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"Think about it - the difference between a cut scene, and actual gameplay. The main difference is that in a cut scene, it is a video. It may looks 3D but it in fact is not, it is a 2D flat video image which depicts a 3D scene. In game, however, everything has to be rendered in real time in 3D. It requires processing power and memory.",
"The question you're asking is about a process called rendering. Rendering is the grunt work that the computer does that turns code and 2d images into a simulated 3d scene. With a cut scene, or CGI they can make it incredibly complex, something that takes hours and hours to render using a very powerful computer. Then take that movie clip and show it to you. This is known as pre-rendering. It allows for very good, very complex computer generated graphics. Video games can't work that way because the scene has dynamic elements to it. Where your character is located, and what direction they are looking in changes the scene being displayed. You can't pre-render this kind of thing because that perspective information is required in advance. So with a video game, the game needs to do the rendering on the fly, as you are playing. That means they don't get to use a supercomputer for several hours to calculate the movement of individual strands of hair on someone's head. So they take shortcuts that are \"good enough\" but still noticeable. And that's why the graphics are not as good.",
"CGI is rendered on very high end hardware and usually takes hours to render. In game graphics need to be rendered 30+ times a second",
"The amount of time taken to render those scenes is massive. So if you have a movie that's two hours of CGI kickassery, that's probably close to a year of hard work from multiple artists. Taking that and applying it to a video game, making every inch of an environment, the characters, and anything else look that good would take even longer. Especially since in a movie, you aren't walking into every nook and cranny searching for things.",
"Former game developer here, The difference is in the capabilities of pre-rendering and real-time rendering. A modern console can render ~400k polygons per single frame - at 60 frames per second. A pre-render in a cutscene or in a movie is going to be in the hundreds of millions per frame. Further, the equations and algorithms we use to light and color each pixel are very different. pre-render doesn't care about cost so much as correctness, because they can always throw more hardware at the problem. In video games, we fake it as much as possible. A pre-render is far more capable in their visual effects than a game engine. The two simply do not compare and they never will. As real-time rendering becomes more capable, which is strictly a hardware problem, so too will pre-rendering.",
"If you'd like an extreme--and extremely stupid--example, I happen to have one: * URL_0 The original of this image was made from two 9999 x 6179 renders in DAZ Studio. It took just about 24 hours to compute each one to produce a red-blue 3D image. It's true that the processor was an old Intel Core 2 Quad, but it still ran GTA V at mediocre settings and 1280 x 768 resolution above 30 frames per second. (And yeah, the background is shite because I hand-drew it on a windy mountaintop.) So there you go: 30 frames per second versus one frame per *day*, helped along by various dumb decisions on my own part. Professionals don't make the mistakes I do and don't deal with obsolete hardware, but it still illustrates the disparity between a native render and a a game render: the game has to be (30 x 60 x 60 x 24 x 2) 86,400 times faster to be playable!",
"There are several reasons. Note that on this list number 2 and 3 apply less to in game cutscenes, even when rendered in real time. Two in particular is why you get stuff like Shepard in Mass Effect pulling out a pistol when you've got an assault rifle. 1) Processing power. This is a big one, doing it in real time on a home PC affords a lot less power than a week on a computing farm. 2) Games are dynamic - you have to have animations which work for any situation. By contrast, in a movie you can specifically do every single animation. Similarly, if you have a character in a game with equipment that you can change, the number of different permutations means each animation will look better or worse for each weapon. 3) Manual tweaks. Sometimes stuff looks a little weird randomly. Maybe a model will intersect another, maybe it will be perfectly accurate but look weird (for instance, lens flair is used in games / movies, but isn't actually realistic). For whatever reason, when this comes up in a movie, they can manually tweak that specific frame / section. Not so in video games."
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66noxx | What is a fascist? | Repost | explainlikeimfive | {
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"Fascism doesn't have a universal definition that can fit every iteration. Due to its roots in extreme nationalism, the \"flavor\" of a fascist ideology will vary heavily based on its country of origin. Hitler's National Socialism was not the same as Mussolini's Fascism, or Franco's Falange. Any homegrown American fascism will not be the same as Nazism. But by and large, fascist ideologies tend to be extremely nationalist, extremely statist, and extremely racist. However, the fascist ideologies tend to share a number of common or similar factors. [Umberto Eco's 1995 essay \"Ur-Fascism\" is extremely useful in this regard]( URL_0 ). Eco (who lived his childhood during Mussolini's rule of Italy) pinpointed 14 common factors that fascist ideologies largely share. I will attempt to briefly summarize each. 1. **Cult of Tradition**. Fascists will attempt to combine their associate their new ideology with much older traditions and traditional imagery. For example, in *Triumph of the Will*, there are many shots of centuries-old churches, cathedrals, and other medieval architecture, frequently with huge Nazi flags flying over them; the objective being to associate Nazism and Nazi rule with the stability and longevity of these buildings. This also played into Nazi architecture (an imitation of classical Greek and Rome) and symbolism (Nazis heavily, heavily cribbed Roman imagery) 2. **Rejection of Modernism**. Fascists will reject modern culture, political values, and art. They will frequently attempt to portray modern, post-Enlightenment values and art as \"degenerate\" in some way. For example, the Nazis suppressed \"degenerate\" art by Modernist artists, decrying it as \"Cultural Bolshevism\" (an attempt by the Jews to undermine German culture from within) and either throwing said dissidents into concentration camps or expelling them from the country. They also encouraged their own vision of \"traditional\" art. 3. **Cult of Action for Action's Sake**. Thinking and intellectualism is weak, degenerate, and unmanly. Fascists persecute intellectuals because intellectuals will be their fiercest and most dangerous political opponents. Thus, they must be discredited, so their professions and habits themselves must be portrayed as \"un-manly\", \"degenerate\", or \"cultural betrayal\". Proper INSERTCULTURE men shouldn't stop to think like a Jew or a woman, they should throw themselves against the Enemy in defense of the Nation without hesitation. 4. **Disagreement is Treason**. Fascist dogma is irrational and largely a pack of lies, and will not survive dedicated analytical criticism. Building upon #3, intellectuals must be persecuted and dissent suppressed. 5. **Fear of Difference**. Fascists stoke ethnic, religious, national, and/or racial divisions to channel the energy of their populations. They must fear the intervention and machinations of a great enemy or enemies. Arbitrary lines will be drawn to divide \"True Nationians\" from \"Others\". For the Nazis, this was the International Jewish Conspiracy against Germany. 6. **Appeal to the frustrated Middle Class**. Fascism's biggest support tends to come from a frustrated middle class that feels they are under intense pressure. This middle class will be resentful of the wealthy and privileged upper class far above them and fearful of the restless lower class below. Fascist takeovers are typically precipitated by major economic stress and the spectre of a socialist or communist revolution. 7. **Ethno-Nationalist Identity** and **Obsession With A Plot**. Fascists will seek to unite their key demographics through extreme ethno-nationalism. They will define what a \"Tue Nationian\" is via arbitrary lines and set that demographic against the Other. The Nazis used the Aryan ideal and anti-Jewish persecution to determine what a \"True German\" was. Additionally, fascists must convince their \"True Nationians\" that they are constantly under threat, under siege, by their enemies. They will do this by drumming up major xenophobic sentiments and targeting minority races and ethnicities. 8. **Paradoxical Opposing Strength**. Fascists must convince their people that their enemies are simultaneously so overwhelmingly strong that they humiliate the nation, but they also weak enough to be overcome by the united effort of the nation and people. Because they must encourage this narrative and in fascism dogma dominates policy, fascist nations frequently cannot objectively estimate the true strength of their enemies and will lose wars as a result. 9. **Life is Permanent Warfare**. Fascists are frequently extreme Social Darwinists. Struggle always improves oneself. The great enemy can only be overcome through struggle. The strong must constantly compete to determine the strongest. In reality, this creates a mess of petty, unstable politics as fascist officials backstab each other for advancement. Hitler's Nazi Party and German armed forces were an absolute mess of cross-jurisdictional conflicts. 10. **Contempt for the Weak**. Fascism is extremely hierarchical, and the masses from whom the fascists have seized power and mandate by force (it must always be by force in a democracy) must be kept under heel. Those who fail in the permanent struggle of life are weak and not worthy of attention. Fascists must despise their subordinates as weaker specimens of mankind. It is a popular elitism that plays into the fascist narratives of Social Darwinism and Ethno-Nationalist Identity. 11. **Cult of Heroic Death**. There is no greater virtue than to die in service of the Nation. Men are encouraged to seek a heroic death on the battlefield above all things. The ideal fascist hero *craves* his heroic death and will not hesitate to throw himself (or his subordinates) into combat against the enemies. This is a critical step in indoctrinating millions of young men into unquestioning military service. 12. **Machismo**. Women are held in contempt and confined to strict gender roles. Their primary purpose is to tend to the home and breed more soldiers. Hyper-masculine virtues are encouraged, and any lifestyle that runs counter (such as homosexuality) to hyper-masculinity is decried as \"degenerate\". 13. **Selective Populism**. The People is a monolithic entity. The People must be willing to sacrifice their individual rights and freedoms and fall in rank to support the State and the Leader. The Leader represents the voice and common will of the People. Fascists will drum up populist imagery and rhetoric in order to seize power, but the population is expected to fall in line behind them once they are in power. For example (and combining with #10), near the end of the war, when the Soviets battled for Berlin, Hitler expressed ultimate contempt for his own people and claimed that the German people \"deserved\" to be annihilated by the Soviets - they had voted him into power (they didn't), supported him as the embodiment of their Common Will (out of fear), struggled against their enemies, failed, and thus deserved to pay the price of extermination. 14. **Newspeak**. Fascists must alter language itself to suppress criticism, dissidence, and \"degenerate\" art. They will frequently use loaded phrases to communicate meaning or encourage certain concepts. Frequently, any communicative media that is not run by the State is suppressed, because the only truth comes from the State, the Party, and the Leader. To go on a slight tangent here at the end, the popular film *Fight Club* is a really great portrayal of the rise of a fictional fascist ideology, and it hits many of these exact points. And yes, Project Mayhem is *fascist*, not anarchist.",
"ITT: People defining a complex political term in terms of other complex political terms. A fascist is someone who: - believes their country is the best - convinces the people he has a plan or making his country the best - wants to elimimate other voices, opinions, and plans for making the country the best - wants to not be held accountable by the country's rules or constitution as he follows through on his plan - is willing to use force to keep the people in check as he follows through on his plan",
"Fascism specifically refers to authoritarian rule via nationalism. It comes from Mussolini's party pre-WWII. It's only associated with the Nazis because Germany was the more prominent Axis power.",
"Fascism is actually an Italian word, *fascismo*, which comes from the harmless word *fascia*, which is simply any device used to keep together or bundle things, like a buckle and strap. Fascismo is called that because it's the idea of keeping everything and everyone together under one \"fascia\". The meaning of the word is actually quite literal. In fact, it should probably be called fascismo in English as well, since the root of the word is 100% Italian, just like solo, arpeggio, scale, opera, orchestra, etc. Fascism is simply the word Mussolini used to coin his type of rule. A fascia is basically a fastener to bundle things together, so if we were to translate the word *fascismo*, it would be something like \"fastenerism\".",
"While there are specific meanings given in other answers, it's important to note that these days, \"Fascist\" is little more than a grab-bag political insult to mean basically \"anyone who doesn't agree with me\". Because of its association with Hitler, 'fascist' is the strongest pejorative used by both Left and Right to discredit/attack anyone they don't like. So be careful when you read that this person called this other person a 'fascist'.",
"In technical terms, a person subscribing to the political ideology of fascism: a socially-far-right, economically- and nationalist-authoritarian movement with a strong tendency to economic protectionism, militarism, and imperialism. Fascism tends to promote a totalitarian military government, and reject democracy. In (inaccurate and) hyperbolic rhetoric, anyone of an apparently authoritarian bent whom the speaker dislikes.",
"Under Fascism there's a strong emphasis on political, social and cultural unity. The [original symbol of Fascism] ( URL_0 ) in Italy is a tight bundle of sticks, symbolising strength through unity: one stick is weak, a bundle is strong if tightly bound. So anything that threatens that unity is a threat to the state and must be suppressed, even if that's just a dissenting opinion. It's important to understand that Fascism alone is not a system of government or an economic model: it appears alongside other systems. For example, Stalinism = communism that had fascist elements to enforce it, while National Socialsim (Nazism) was a warped, belligerent form of Socialism that favoured large private industries, with Fascism to ensure national unity behind the state's goals.",
"A person supporting a system of government based around extreme authoritarianism, nationalism and optionally a \"third position\" in economics against both capitalism and communism, or a member of a party that supports that system."
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66onrk | When and why did 18 years old become considered "adult age" worldwide? | Repost | explainlikeimfive | {
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"Eighteen is, on average, the age when people stop getting any taller, so many societies adopted that age as the age of adulthood."
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66pr62 | what is morning breath and why do we have it? | Repost | explainlikeimfive | {
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"Your mouth is filled with hundreds of millions of bacteria. Generally when you sleep, your mouth is open, which dries it out. Your salivary glands are also much less active when you sleep. This allows those bacteria to hang around and produce nasty-smelling compounds that are not swept away by your saliva and swallowed as they are when you're awake. If you want to reduce the stench of your morning breath, keep a glass of water next to your bed and have a few sips every time you wake up."
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66pxej | How can baby animals start walking basically immediately after their birth, but humans can't? | Repost | explainlikeimfive | {
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"Some species of animals are *precocial* which means they are relatively mature and mobile from the moment they are born (or hatched.) Humans are *altricial* which means our young are born pretty much helpless. But we are far from the only altricial species! Rabbits are born blind and hairless, for instance, which is why rabbits give birth underground. Most other primates are altricial as well. It has to do with evolution and habitat. For instance, cetaceans (whales and dolphins) are precocial, because they live in the sea, and their babies would drown if they couldn't swim from birth.",
"Humans are not able to survive alone. They are not very mature at birth, because their huge brain needs to grow and if their head was any bigger it wouldn't fit through their mother's pelvis. It takes months for it to grow enough that they can crawl, and years before then can walk and run adroitly. Smaller brains are simpler, less flexible, and fit into a smaller head, even though they can still control a large body."
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66t6p8 | What is Net Neutrality? | Repost | explainlikeimfive | {
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"its basically forcing internet service provider companies to treat all internet sites and services as equals instead of picking and choosing or setting up impossible hurdles for whom they want , either for money or other stuff. like imagine you had watchflicks and could potentially make a lot of money but the ISP couldnt handle the traffic or doesnt want to invest into the infrastrucuture/ R & D and instead they make it so your customers can only watch raw potato quality video after they buffer for 3 days and 2 nights in the bahamas, courtesy of you."
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66t71q | why school busses don't have seat belts? | Repost | explainlikeimfive | {
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"The primary purpose of a seatbelt is to prevent ejection through the windshield. This is a smaller risk in a bus because of the seat configuration and because of the mass of the vehicle. If a bus collides with a car the result will be that the bus pretty much just plows right through it because it weighs 10 times as much."
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66u9pa | "Beer before liquor, never been sicker. Liquor before beer, you're in the clear" | Repost | explainlikeimfive | {
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"It is a myth. It is based on the fact that if you drink hard liquor later in an evening of partying where you have already gotten drunk off of beer you will be more likely to drink too much and become too drunk, thus making you have a worse hangover and possibly making you sick during the night. But if you drink hard liquor first to get drunk then drink beer through the night you will tend to get less drunk due to beer having a lower amount of alcohol in it.",
"The mantra addresses the concept of \"tapering off\". Hit the hard stuff early and transition to the weak. It applies to most substances. Do a couple lines and then bump as necccesary. Dab and then smoke to maintenance the high. Start with a full tab and take a half if you aren't peaking. Remember: Alcohol is alcohol and drugs are drugs. Be smart about things and you'll always be \"in the clear\"."
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66uo58 | Why do rockets start vertically and not horizontally likes planes to reduce the needed thrust for the takeoff? | Repost | explainlikeimfive | {
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"It takes less fuel to launch vertically, get higher in the atmosphere where the air is thinner (less resistance to work against), and curve gradually to increase orbital velocity. The goal is to get out of as much of the thick lower atmosphere as possible using as little fuel as they can"
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66vyp3 | What are Gödel's Incompleteness Theorems? | Repost | explainlikeimfive | {
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"Maths is based on things called axioms. These are rules that we accept before we can do maths. For example, 10 + 5 = 5 + 10 the order in which we add numbers doesn't matter. Axioms are just rules we take to be true and using these rules we try and find out other things and prove whether something is true or false. Obviously in maths, in particular arithmetic (adding, subtracting ...), we have many axioms and those axioms form a system. A complete system is one where you can prove whether something within the system is either true or false. A consistent system is one where you will never get a contradiction i.e. something that can be proven both true and false. Godel's theorem states that you can never have both of these in an axiomatic system. Meaning you will either end up with a contradiction or there will be certain things that cannot be proved true or false no matter how hard you try",
"Mathematicians like to have systems for answering questions. You probably learned some of these systems in school. Long division is just a system for answering questions like \"What is 156/12?\" But mathematicians don't like having a different system for each kind of question. They want one system that can answer any kind of question. The first incompleteness theorem proved that this is impossible. No matter how cool your system is, there will always be some questions it can't answer. The second incompleteness theorem gives an example of an important question no system can answer. Specifically, no system can answer the question of whether they will ever contradict themselves."
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66w3yj | How is it possible for a "master key" to exist? | Repost | explainlikeimfive | {
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"A cylinder or 'Yale' lock has a rotating cylinder inside a fixed lock body. There are vertical holes in the lock body and cylinder, with pins in them, with each pin being cut into two pieces. The key lifts the pins by just the right amount so the cut lines up with the join between cylinder and body so the cylinder can rotate. If the wrong key is used the cuts don't line up and the pins stop the cylinder rotating. It's much easier to explain with a diagram: URL_0 To make such a lock work with a master key, each pin simply has two cuts not one. One set of cuts will be made to line up by the master key, the other set will be made to line up by different keys for each lock."
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6711se | What is a VPN and what does it do? | Repost | explainlikeimfive | {
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"The internet is similar to a postal system, everyone has an address and with that address, the post office knows how and where to send something. On the internet, this is done in the form of IP addresses, usually 4 different numbers that act as everyone's address. When you want to connect to google, your computer uses a system called DNS to find the IP address of google and send stuff back and forth between it. However, the person controlling your wifi can stop a signal to an address similarly to how a post office can stop your package from reaching other post offices if they don't want you sending something to that address. What to do then? Well, a VPN acts as a proxy in this case (it can be used for more, but this is its most common use). You want to send a letter to bob, but the post office doesn't let you send a letter to bob. So what you do is you go to your friend Joe who lives a city over and ask him to forward all your packages to him to Bob. And if bob wants to send you packages, he sends them to Joe, who sends them to you."
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673pp1 | Why does splitting an atom release so much energy? | Repost | explainlikeimfive | {
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"More specifically, nuclear reactions are not splitting just one atom. They split one atom, which succeeds at splitting more atoms, which split even more atoms. Each time those atoms split, they release a small amount of energy. Do this several billion billion times in a very short amount of time and you get a big release of energy, also known as an explosion."
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673rc8 | If you have a really long stick. | Repost | explainlikeimfive | {
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"No, the pressure moves at the speed of sound. This would be kind of entertaining because the stick, from a faster-than-light-thought-experiment standpoint, would be really curved.",
"No. An imaginary perfectly rigid stick would be impossible to rotate fast enough, its 'moment of inertia' - resistance to having its spin sped up - would increase without limit as its tip got closer and closer to the speed of light. A real stick would bend."
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673riy | Why do some body parts (e.g. breasts and penises) vary so widely in size and appearance while others (e.g. fingers and ears) stay within a relatively narrow range of size and appearance? | Repost | explainlikeimfive | {
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"text": [
"It's because breasts and penises are soft tissue while your fingers have bones in them. The bones are what ultimately dictates their size, and don't allow for as much variance across the population.",
"I think it has allot to do with hormones and genetics. So fingers and ears aren't that greatly affected by hormones compared to genitals and breasts. Also there's an evolutionary aspects to the shape of our ears, feet, hands, head, nose etc... They're shaped that way through evolutionary means. For breasts and genitals they generally all do their job so shape and size isn't as important as long as it works for what it's there for (breast feeding, pro creating). It may also have to do with what we generally see and how attractive ppl find others. Generally you don't use genital appearance or breasts size as a deciding factor to find a mate. I'm no expert but this is how I look at it, not sure if it answers and if someone has a better answer, I'd love you be educated on this as well."
],
"score": [
5,
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|
673wzj | Why is salt and pepper used to season EVERYTHING in the culinary world? Like, what makes these two things so special? | Repost | explainlikeimfive | {
"a_id": [
"dgngm61"
],
"text": [
"Pepper isn't *that* ubiquitous; it very much depends upon the cook and the style. Salt, on the other hand, is one of the basic flavours to which humans are sensitive, so it's hardly surprising that we like to be able to regulate the level of it in our food. It's like sweetness in that respect, only it doesn't occur naturally in as many foods, so having it as an additive is more useful. That's before we even consider what others (at the time of editing, BrokenSpectr and bashar_speaks) have noted about the body *needing* sodium and potassium, and their chlorides being among the most readily-available salts for consumption (OK, that's not exactly what they said, but I don't think inserting extra information should be a problem)."
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674bwr | If a Nuclear war can bring Havoc to worldwide climate then why that didn't happen when nuclear tests were in full swing ? | Repost | explainlikeimfive | {
"a_id": [
"dgnjqmw"
],
"text": [
"Well, to be honest, a few theoretical problems relating to nuclear weapons didn't really pan out. For one, some people thought even a small nuclear test would start a chain reaction in the Uranium in the Earth's crust, effectively scorching the entire surface of the planet. Or maybe igniting the atmosphere, and leaving us like Mars. It's not precisely 'nukes' that were going to cause climate havoc. Nuclear winter isn't really nuclear, necessarily. It just means enough crap gets kicked up that it blots out the sun for a while, and long-term increases the reflective powers of the atmosphere: less radiation, cold as Fick, ice age. You could get the same effect from a series of huge volcanoes, or even a big enough/proper distribution of conventional weapons. There's actually a device that can output particulate into the atmosphere, lowering the temperature quite drastically. It's more of a weapon than a solution though. I seem to have losty thread a bit. Nuclear winter would require multiple bombs in multiple locations. That said, large scale testing (that is, the big Russian bombs) did impact the weather for relatively short periods, similar to the eruption of Mount St Helens. Edit: Oh or a really big asteroid impact. Or possibly setting all the oil wells on fire at once. Or a magma plume ignites a huge coal seam (I think this might have been the cause of one of the major extinction events but I'm not sure). Remember the dinosaurs? Anyway. The end is fucking nigh, you know?"
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