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3vxi9w | what could theoretically happen if the new fusion reactor has a problem when it's turned on in two days? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3vxi9w/eli5_what_could_theoretically_happen_if_the_new/ | {
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"Well, first thing, the new fusion doesn't even fuse (for the moment). It runs on simple non-fusing plasma (hydrogen).\n\nAnyway, the worst that could happen is some short circuit or cooling failure in the superconducting magnets, which results in a few million in damages and a bunch of very disappointed scientists.",
"Fusion reactors don't undergo chain reactions like fission reactors do.\n\nYou have to set up a very specific set of circumstances for fusion to start, and if anything goes wrong, the reaction is disturbed and ends.\n\nThat said, there is a lot of industrial equipment involved, and a lot can go wrong with it, but that doesn't have anything to do with fusion.",
"I presume you're talking about the German W7-X Stellerator.\nIf that's the case: it's not a fusion reactor.\n\nIt's not designed to fuse anything, but rather as a method of testing plasma containment.\n\nHowever, even if it was a fusion reactor - the worst problem that could happen is that a magnetic constrictor fails, causing plasma to come in contact with the reactor vessel.\n\nThis would melt the inside of the vessel, damaging that segment. The plasma would expend all its energy doing this, and would not escape containment.\n\nAlthough it's really hot, there's not much of it, so although each volume element of it contains a lot of energy, there isn't much overall energy."
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2kmb6j | why don't most christians interpret the bible literally? who decides what is literal? | Not trying to be judgmental... just an honest question. Considering how the Bible is supposed to be the word of God, how is it that Christians feel like they can pick/choose what to take literally and what is just an allegory? I'm wondering this because among the recent Pope Francis evolution hype I've been reading that most Christians actually take Genesis to be an allegory. Who decided that it was an allegory and how do they have the right to do so? Also, couldn't that mean that the whole Bible is just one big allegory and that nothing should be taken literally at all? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2kmb6j/eli5_why_dont_most_christians_interpret_the_bible/ | {
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"You probably need to study the history of the Bible and how it came to be. It didn't just land here, brought down from heaven by an angel. The books which came to be called the Bible, were selected by a council. Constantine the Great basically forced them to come together and define not only the Bible, but what the Christian faith itself meant.\n\nHe did this becoz he intended Christianity to become the religion of his Empire, the Holy Roman Empire. From this, he claimed the right to rule as God's chosen, God's anointed. If you opposed him, you opposed God.\n\nThat was the beginning of the idea. Politics. Wrap your mind around it.\n\nSo, to enforce the absolute authority of the Emperor, it was necessary to enforce the idea of the absolute authority of the Bible as the Word of God. \n\nIt's not a difficult idea. It's a genius idea.\n\nSo, that idea gets passed down through the ages, coz each king/emperor/whatever decides it's a good way to keep people under control. Until round about the French Revolution when people start cutting off the heads of priests and basically just destroy the authority of the church altogether. \n\nThey still keep priests around but made sure the priests didn't get up to their nasty tricks of stealing from the poor to enrich themselves. Hell, Napoleon [kidnapped the pope](_URL_1_).\n\nStill, the idea that the Bible is the Word of God keeps floating around, even though Bible scholars will tell you that there was no such thing as a book containing all the books of the Bible together until [Erasmus](_URL_0_) worked on putting it all together. Until then, people just had bits and pieces all over. \n\nThere is a whole area of study of the manuscripts that make up the bible. You can actually study this in school. Bits that leave things out, bits that are added in later, bits that have words in the wrong order, etc.\n\nIf you think that God \"magically\" got people to \"magically\" write it out so that what we have now, is the correct thing, where does that leave the people who were using all the bits from before our \"magically\" correct version?\n\nIt makes much more sense to realise that the value of the Bible is deeper than as a literal word of God. It is more a conversation between God and mankind, a small subset of mankind, that has some very deep insights both into man's nature and possibly, into God's.\n\nThe idea that a single book could even begin to define God, is the most simplistic understanding of the most simpistic God that man could ever imagine. Such a God could only ever be the product of man's imagination and would in no way ever represent the fullness of whatever being that may exist out there. \n\nThe deepest truth of the Bible may be just in the struggle to give God a name. The writer could only come up with \"I am who am\". Words are useless to describe the real God.\n\nIf you truly want to know God, you must humble yourself, and beg him/her to reveal him/herself to you. Keep doing that and maybe someday, your prayer will be answered.\n",
"The first thing to note is that the Bible isn't really a book. It is a collection of dozens of smaller books written by many different people from different cultures over a very long period of time.\n\nMost Christians believe that the Bible was divinely inspired – that at the very least, its creation and compilation was influenced by God so that the stuff we need would be in there. But exactly what that means depends on who you ask.\n\nThere are some Christians who believe that every narrative part of the Bible is meant by God to be a literal account of something that really happened. This is a relatively new method of interpreting the Bible, and it runs into a number of problems that I don't think require explanation. But this is not the only way of looking at it.\n\nTake the book of Job, for instance. A lot of people – including many non-Christians – take this very literally. That is, the book of Job is about some actual historical person who God was dicking around with. But if you read the story the way you would read any story, you'd take away something very different. The author of Job was writing about one of the classic questions of any religion: why do bad things happen to good, devout people? In the book, there's some framing device involving God and Satan, but the point is that *Job* doesn't know why bad things are happening to him. Various characters offer their own perspectives and arguments, which Job rejects.\n\nFinally, God appears. He doesn't explain why Job is suffering. Instead, he tells Job that running the universe is a task hopelessly beyond the reach or comprehension of a mortal man. He doesn't explain why Job is suffering – instead, he tells Job to trust that he knows what he's doing. Then, he gives Job back everything that he lost and more, and Job lives to be a hundred forty and has scads of grandkids.\n\nIf you read the story from a literary perspective, there is a clear moral, one that is consistent with the general thrust of the Bible as a whole. If you read it \"literally\", then the background details – that Job is suffering due to some cosmic bet that was glossed over in the space of a paragraph or two and didn't seem all that important – overshadow the point of the story.",
"If they were to interpret the bible literally, their lives would suck. No bacon, no ham, no shrimp, no blended fabrics, women wouldn't be allowed in churches and would have to live in a separate house during their period. Women wouldn't be able to vote, marriage would involve basically being sold by one's father to one's husband. Basement dwelling sons who won't get jobs would be drug to the city limits to be stoned to death.",
"One thing that I haven't seen mentioned already is the importance of genre in interpreting the Bible. Genre is one of the most important things to consider when deciding how to read certain parts of the Bible, but it often gets overlooked. The Bible is a collection of various writings from various authors from different time periods, and they are not all written the same way. You would not read a history book on World War 2 the same way that you read a poem by John Donne. I don't remember all of the genres off the top of my head, but here are some examples:\n\n* 1 Samuel, 2 Samuel, 1 Kings, 2 Kings = Historical narrative (self-explanatory)\n* Psalms, Song of Solomon = Poetry (same as all other poetry, it is meant to express emotions (usually praise to God), not necessarily teach historical accuracy)\n* Job, Proverbs, Ecclesiastes = Wisdom (meant to teach life lessons and such. May overlap with poetry)\n* Ezekiel, Jeremiah, Jonah = Prophecy (Meant to reveal God's plans for the future)\n* John, Luke, Mark, Matthew = Gospel (contain biography about Jesus' life mixed with teachings and other foundations of Christianity)\n* Collosians, Romans, Phillipians, etc. = Letters (Written in the same way you would write a letter to friend. These are meant to edify and strengthen the church)\n\nI feel like I might not have been completely clear with all this, so feel free to ask any further questions!\n\n\n"
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9joxsm | what do jehova witnesses believe in exacly? and how to they differ from christians? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9joxsm/eli5_what_do_jehova_witnesses_believe_in_exacly/ | {
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"Christians believe Jesus is God. JW believe Jesus is God's creation. This is the main difference but there are many others - for example, JW think Jesus was nailed to the column, not the cross.",
"I was raised as a JW but left when I was 15. \nLots of things are similar, some are different. \nBasics are they are a doomsday cult and have unofficially predicted the end days many times. They belive only 144000 people will ever be in heaven the reat of the \"saved\" will live on a paradise earth much like the garden of Eden. They dont belive in a literal hell but an abyss of nothingness for every one not saved. \nThey go door to door to save as many people as possible, and are very bible literal with some aspects and not with others. This is where their belifes of no birthday celebrations no Christmas, Halloween and other celebrations stem. Also no blood transfusions and discourage higher education. They also preach against becoming involved in politics. \nAny one who speaks oit against them are considered apostates and shpuld be shunned, especially former members. So they also discourage associations outside of the church. ",
"Jehovah's Witnesses *are* Christians. They believe in the divine origins of Jesus Christ, and that he is the son of God and died for humanity's sins.\n\nThey have some different views on doctrine from mainstream Christianity, and adopt some distinctive practices that distinguish them from other Christians, but the differences aren't really as radical as they seem.\n\nI'm not sure ELI5 is a good venue for discussing those nuanced differences.",
"Hi! I was raised by some non-practicing JWs and from my understanding it is a more literal (fundamentalist) intepretation of of the new testament. \n\nThe most often question is why JWs don't celebrate holidays and such and it's simply because they're not in the Bible - the \"Christian\" holidays we see today are appropriations of other religions. (Christmas = Yule, Easter = Eostre, etc).\nAs for birthdays the sweets and presents have non-christian origins, and in most biblical references to birthdays someone is murdered - one of two direct references to birthday celebrations is when John the Baptist has his head literally served on a platter.\n\nAs a clarification, am not a JW. Just have a very basic understanding of some of their beliefs.\n\nFeel free to message me. ",
"They believe many of the same things as other Christian denominations, but they have some significant differences too. Here are some that come to mind:\n\nJW's do not believe in the trinity (that is, that the father, son, and holy spirit are all one god) but rather Jesus was created by God.\n\nThey reject symbolism and contend that Jesus was crucified on a post, not a cross. They also see celebrations of birthdays and holidays as idolatry and thus prohibit members from celebrating.\n\nAll literature must come from or be approved by the Watchtower, and reading anything else is strongly discouraged.\n\nMembers are strongly discouraged from associated with non-JW's, and interactions with others should be for the purpose of converting them. Those that left the JW church are especially shunned.\n\nThey are told to avoid becoming involved in politics or joining the armed forces.\n\nThey are to refuse blood transfusions for themselves and their children, deriving from a line in the Bible that states that people are not to consume blood."
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61jtf0 | why are there only a slim variety of chinese/korean last names? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/61jtf0/eli5_why_are_there_only_a_slim_variety_of/ | {
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"All the Kim's in Korea are self selected last names. Until the 1890's no Koreans had last names unless they were royalty. So then their Japanese overlords forced everyone to pick a last name. \n\nKim's, Park's (Paks) and Lee's were some of the richest and most powerful royalty, so everyone picked one of those names, as they were the most badass names available.\n\nThat's why most people in Korea have one of those last names.",
"Historically last names weren't actually a thing, they functioned more like titles owned by the nobility. During a period when the noble class system started dying out, commoners started taking up last names for themselves. Lee, Kim and Park surnames signified lineage of royalty, so many went with those.",
"I believe there are at least thousands of Chinese last names, but only a hundred or so are commonly seen, and even fewer are known to westerners. What I'm saying has no basis other than my Chinese origins, but hear this: \n\n1. Polygamy was common throughout Chinese history, so say you have 1 man with the last name Wong, who marries 5 women with all different last names, but all 10 of their children will have the last name Wong. So common family names get exponentially more common\n\n2. A ruler can bestow his last name to his subordinates as a token of honor\n\n3. People settle in a place and name themselves after the place, so there were villages where the entire village had the same last name\n\n4. Immigration to the west did not happen with \"variety of last names\" in mind ",
"there ARE lots of chinese last names, but because chinese is a character-based language, lots of \"words\" sound the same. the sound of one character is the same as many, many other characters that have different \"spellings\"; when you speak chinese, you use context of the phrase to figure out which character \"spelling\" is being used for that certain sound.\n\ntherefore, when you try to translate chinese last names into english characters, lots of them sound similar despite being actually different. also, the nuances of the sounds (like tones) are hard to translate. "
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8pkh6i | how can carbon dating tell when a specific set of rocks is from (such as when they research when a crater formed) when the material was already there prior to the event? it's not as if the rocks simply came into being in that moment. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8pkh6i/eli5_how_can_carbon_dating_tell_when_a_specific/ | {
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"C14 is used to date biological remains. It can’t be used for most geological research because it simply can’t go that far back. If someone is C14 a crater what they’ve likely done is dated the tree remains that got burned by the eruption.",
"Carbon dating looks at organic material in particular, not rocks, although it can be used to estimate the age of the rock organic material is deposited in. It's a subset of radiometric dating, which I point out just because a lot of people don't realize this.\n\nThe short of it: while plants are alive, they take up carbon from the atmosphere. Animals also eat these plants and incorporate the carbon into themselves.\n\nWhen a plant or animal dies, it stops taking up carbon.\n\nSo, straight so far right? There's a dead animal there, and it has carbon in it from the atmosphere.\n\nBut not all carbon is the same. Some forms of carbon undergo radioactive decay at a known rate (the half-life). So we can look at the atmosphere and (fake simple numbers) see that it is 1 to 1 decaying carbon and not-decaying carbon.\n\nAfter one half-life, an isolated sample would be .5 to 1 decaying carbon and not decaying carbon (the decaying sample has decayed by half). After two half-lives you'd have .25 to 1 decaying, and so on.\n\nNow, when the animal is alive, it keeps taking up new \"decaying\" carbon, so the ratio had stayed 1 to 1. But once it died, this stopped. \n\nSo if you measure the carbon in the body, and you see .25 to 1, you know two half lives have passed.\n\nIf the half-life is 100 years, you can estimate the corpse is 200 years old. \n"
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7xmmzh | how are new sythesiser sounds made? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7xmmzh/eli5how_are_new_sythesiser_sounds_made/ | {
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"A computer program tells the machine what shape of sound wave to produce, using a series of numbers to describe the actual height of the wave over time. Different wave shapes make different sounds.",
"The first synths were *analog*. They used a bunch of simple electronic circuits (usually oscillators with various controls) to alter a voltage over a period of time. As any sound is a waveform that can be represented by a voltage that varies in magnitude (amplitude/volume) and oscillation (frequency), by controlling the voltage you can make any sound. Since the first synths were fairly simple, you could not get all that creative. Later, fully digital synths were invented...using FM synthesis. Again, the control over the waveform became more exotic...and so, creative people could figure out how to make interesting sounds. Things got really wild when *sampling* synths were invented. In these, you could start with a real world sound (which may have a *very* complex waveform) and then use simple controls to alter it in interesting ways. So, really, you need both the electronics *and* the creative users to create new sounds."
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qa005 | wart removal | When removing a wart, what makes it become all white? What chemicals are in the over-the-counter products that makes this happen? What happens when doctors use liquid nitrogen to freeze them off? Is one method more effective than the other? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/qa005/eli5_wart_removal/ | {
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"the caustic chemical (or freezing spray) basically aims to kill and remove the layers of skin around the core, which is usually a viral infection, and kill that too. \n",
"When you use something like salicylic acid, it kills the top layers of the skin. They slough off the rest of skin, so they appear white. ",
"I'm not gonna lie. Warts are really cool. They're like the first step towards zombies, which you've gotta love. Basically, you've got a virus (Human papillomavirus, to be exact) that alters the genes in your skin so that the top layer grows way faster than the stuff around it, and holds on to dead skin longer than it should. The not-so-cool part is that this is technically a tumor. It's a benign tumor that won't leave the surface of your skin (generally), but a tumor nonetheless.\n\nWhat the freeze treatment does is make the skin a hostile environment for the viral cells (and the healthy cells surrounding them). If all goes well, this will kill most of the infected cells, and cut off the blood supply to the remaining stragglers until they die on their own. The white stuff is just flaking dead skin. When using a home treatment, the white stuff is some salicylic acid crystals mixed in with a layer of dead skin.\n\n... I should really get my plantar warts removed..."
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48ueor | if it's safer for a child to ride in a backwards facing car seat why aren't airplanes designed so all seats face backwards? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/48ueor/eli5_if_its_safer_for_a_child_to_ride_in_a/ | {
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"Mythbusters did this. Rear facing seats are significantly safer but they freak people out so too bad we don't get them. "
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3kin00 | how can "car software" have +-100 millions lines of code, when f22 raptor fighter jet has only 2 millions? | I ask this question while assuming this image: _URL_0_ is based on reality. If it is not, please do share your information about this, too.
Generally I am astonished by the massive number of lines of code that's supposedly controlling the car's operations (or what else?).
*I mean ... LHC with 3.5 millions lines and - again - a car with 100 millions?*
**HOW.** | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3kin00/eli5_how_can_car_software_have_100_millions_lines/ | {
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"To be honest, I'm fairly certain this entire infographic is bullshit. While the source link doesn't work anymore, I seem to remember back when this was released that most of the sources were \"some guy claiming to work on x\". \n\nThough I would estimate that a modern car probably does have more lines of code than an F22 because modern cars have so much to deal with now. Not only is there the computer that deals with the health of the engine, tires etc, but the voice activated systems, the plug and play of media devices, bluetooth, usb. They have to be able to cope with a vast variety of devices.\n\nJust remember that counting lines of code is never ever a good metric of what makes a good program. A general rule of programming is that your program will likely spend 80% of the time in 20% of the code. Sometimes code will never be used at all.",
"There are all sorts of problems with comparing the figures, even if we assume they're all correct.\n\n\"One line of code\" isn't really a well-defined measure of the complexity of the code, since different languages allow you to do more or less in one line. A low-level language may require three lines to add two numbers together, while a language like C++ will do a whole complex calculation as one line. It's like counting the length of books in characters, but some are written in Chinese where each character is equivalent to a whole English word.\n\nThen we have to consider which code you count. Programming languages include a lot of libraries of code other people wrote to do common things - does that count even though it wasn't written specifically for that car/jet? Many ATMs run on Windows, so does an ATM include 40m lines of code before we even start writing the code that takes your PIN and hands out cash? If I write a short book in German and then tape an English-German dictionary to the back to let you understand it, do you count every letter in the dictionary in the length of the book?",
"The jets software will have been written specifically for it, with each line of code designed and evaluted individually to try and ensure it cant go wrong.\n\nA car on the other hand will use much more \"off the shelf\" software with common components like the OS, device drivers, software libraries etc. These all add up to the line count, but arent all critical to the running of the car",
"It is because the F22 Raptor has a custom made computer (embedded system) which implements only the operations needed by the jet (like you wouldn't add functionality for a iPhone). While the car, in order to be cost effective and easier to produce, has a more generic computer, complete with a OS. Now add the already made system calls and functions to the car's code and you end up with tons and tons of extra code. Also as others noted, complexity or lack of cannot be measured just by the lines of code.",
"I'd assume because the F22 has custom written assembly from the ground up, which is very low level (think machine code), while most car infotainment systems run full operating systems like linux or webOS or windows, which by itself comes with millions of lines of code. (which is probably what that infographic is counting)"
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8wvd14 | why does usa allow zimbabwe to use the usd? and what stops everyone else? | Doesn't zimbabwe affect the value of the US dollar? Also, if two radically different countries can share a currency, why can we not have one giant mega currency similar to the Euro, but the Eartho or New Earth Dollar? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8wvd14/eli5_why_does_usa_allow_zimbabwe_to_use_the_usd/ | {
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"Zimbabwe buys USD, it doesn't print them. You can change the value of a currency by drastically adding or removing the number of them in circulation, and Zimbabwe is so much smaller than the US that it just can't.\n\nThere are convenience arguments for a mega currency as you put it, but the problem is when economies collapse. It is up to the better off countries to support whichever nation collapsed and provide that government with more money. This happened with the euro, where Germany's currency drops because of spain/greece/ireland, because it is all the same currency. That is the major risk of sharing a currency.\n\nEdit: not iceland, my bad",
"The US can't really stop a country using the dollar without massive amounts of work. The dollar is used all over the world for all sorts of things. To take one example, you have to buy oil in USD. Because it is the main world currency, governments keep some on hand at all times\n\nThis suits the US just fine. Because everyone relies on the dollar, other nations will be at pains not. To tank the US economy because it makes them poorer too\n\nThe USD isn't shared though. Zimbabwe doesn't have any power over it. Zimbabwe is tiny compared even to one US state, so it doesn't make a difference. Other countries use the dollar too. Like Vietnam and Cambodia. On the ground, dollars are accepted currency. Some countries, like Montenegro, use the Euro\n\nIf you want a currency union between equal sized nations, there has to be value flows, or else all the wealth gets sucked into only a few places. This is happening in the Eurozone now, with money moving from South to North. To fix this, you need the North to give money to the south. That requires a close political union",
"/u/Petwins and /u/jimmyrayreid have covered the specifics pretty well but if you want some further information on the concept/s involved in paper money here's a playlist from Extra History on the subject: _URL_0_",
"Zimbabwe is using US dollars the way everyone in the US uses dollars, which is just to pass them around in exchange for goods and services. The US doesn't *allow* Zimbabwe to do it, they're just doing it.\n\nZimbabwe doesn't significantly impact the value of the dollar for a few reasons, primarily because Zimbabwe can't print new dollars. They can't make promises to give other people more dollars later in exchange for goods or services now, the way a treasury bond works. When the US makes that kind of promise, the person holding the bond knows absolutely 100% that they will get those dollars because the treasury can literally just print them off. Zimbabwe can only promise that they will somehow *earn* more dollars to give out.\n\nThere are several countries that use the US dollar as their currency. Still others tie the value of their currency directly to the dollar, in the same way that the US dollar *used to be but presently isn't* based on gold. The benefit to this is that you can have a very stable currency, because the US dollar is pretty stable. That's why the US dollar used to be based on gold - the scarcity and demand for gold generally don't change much, so being able to say \"I will give you X gold for Y dollars\" keeps your currency stable. You know that at any time if you don't want dollars anymore (essentially, the dollar has lost value *to you* and you want something of greater value) you can at any time trade your dollars for gold. That makes you confident in accepting dollars as payment because you can get rid of them later and get something valuable back. Change \"gold\" for dollars and \"dollars\" for whatever local currency they're using and you get a similar effect...\\*\n\n(We don't really base the value of the dollar on gold anymore. Rather, you're confident that other people will still accept the dollar for whatever good or service you want, so you know you can still get something with that dollar, because you're confident that the United States will continue existing in a way that maintains the buying power of that dollar.)\n\n\\*...Assuming the dollar stays stable - a reasonable bet for most of recent history, but it's still a bet. The reason most countries use their own currency is so they can have control over it. By controlling how dollars enter circulation through bank lending rates and the issuing of bonds, we can have a measure of control over the value of a dollar. Zimbabwe sacrificed that control. If we do something wonky to the dollar, their economy suffers as a result. *They* aren't big enough as a world economy to affect the US very much. The US economy is the largest in the world, so what we do very much affects Zimbabwe even if they *weren't* using our currency.\n\nSimilarly, if the US spontaneously ceases to exist as a country and the dollar becomes worthless, every country that relies on the dollar as their currency or the backing of their currency is going to have *a very bad day*.\n\nAll of those problems are associated with sharing a currency with another country. It's a problem the Eurozone has faced again and again - one country (usually Greece, sometimes Italy, sometimes someone else) has a failing economy and makes promises on the Euro that it can't repay. In order to keep the Euro from crashing as a result, other countries have to bail them out (usually Germany). If you can't make promises on the currency, then you have no control over it, which is not what countries generally want. If you *can*, then you *do*, which is not what *other* countries using the same currency generally want. Even if you do absolutely nothing wrong or irresponsible with the currency, if your economy crashes everyone else is tied to you and your crash will have a much stronger impact on them.\n\nWhich is why we will almost certainly never have an Eartho outside the realm of science fiction and space travel. To most countries, the benefits of having a single currency aren't worth the problems associated with giving up control over that currency. Hell, look at the US right now: **without discussion about whether it's right or wrong or good or bad** our administration is obsessed with trade deficits with our historically closest trading partners and the control they have over the US economy just through organically emerging trade between private companies, much less if Canada and Mexico were issuing bonds in US dollars!",
"When the risk posted by the instability of your own hyperinflated currency outweighs the risk of not having control over your own monetary policy by using a foreign currency, folks resort to using a foreign currency.\n\nBasically, they've concluded that however bad US monetary policy is, it can't possibly be worse than their own.",
"No downside for the US when other countries use their currency, increased demand increases value. Important thing to note, they use US dollars, they cannot print them.\n\nActually a lot of US dollar value comes from fact it is standard currency in a lot of international transactions like oil. Saddam changing from US dollar to Euros for oil and trying go convince other oil countrys to do same is generally seen as one of the motivations for the second invasion of Iraq. Without that need for dollars to do international buisness the dollar would be worth a lot less than it is.\n\nThe downsides are for the other country, they have a currency that they have no control over nor ability to increase or decrease circulation, a major tool in managing ones economy, especially inflation. Though on other hand, having that control can get them into trouble, Zimbabwean dollar became so worthless because they printed so much to pay their debts that at one point 100 trillion zim dollars were worth 40 U.S. cents.\n\nOther countrys, with a currency that still has value dont use the dollar because they dont want to lose that control\n\nThese are also the reasons a single worldwide currency are a long way off",
"I've been traveling in Africa lately and colleagues of mine have for years. USD is widely accepted everywhere. In most countries you get visa on arrival it is paid for in USD, some accept EUR but USD is the go to. Same in airports, local currency is preferred but USD prices are always available. \n\nI get what you're saying about using it exclusively as a day to day currency but it's been used as a \"happy medium\" for some years now across Africa ",
"Nothing stops them from using dollars like anyone else. A more interesting question is what stops them from counterfeiting USD? We don't exactly have normal relations, and AFAIK no one has gone to war over counterfeit currency. ",
"I didn’t know they used the USD for thier currency, but if they do, the US wouldn’t want them to stop using it. Its pretty much a free loan to the US. ",
"Don’t know if it’s been mentioned or not, but Ecuador does something similar but they instead pegged their monetary sector to the US. Any country can chose to peg their currency to the any other one but what stops countries from doing it is that they then lose control over their economic policies. Also, if the country who’s been pegged, in this case the US, has an economic downfall it will be felt much worse on countries who did the pegging. ",
"I have a Bachelors in Economics. Here's my ELI5:\n\nWe have to start with a little background before getting specifically to Zimbabwe. To purchase US goods and services, you have to pay for them in USD. This isn't just the case with things you and I buy on a regular basis like groceries, but also American investment opportunities such as real estate or stocks. This works both ways as well, so if an American wants to buy Chinese stocks they have to trade USD for Yuan. Naturally, as the premier economy (for now at least), almost everyone needs US dollars for various reasons. \n\nPeople needing to trade dollars for yuan and vice-versa get together to form a \"market\" with supply and demand. If the US economy has better returns compared to China's, then more people want USD to buy US investments, making the dollar \"worth\" more relative to the yuan. The opposite is true as well (read about the laws of supply and demand if you want to know more). \n\nSo why does this matter for an entire country like Zimbabwe? Because the value of their currency compared to those of the countries they trade with directly influences their economy. Let's say it takes 4 Zimbabwe dollars to 'buy' one US dollar. Suddenly, Zimbabwe finds a massive new oil resevoir and people need Zimbabwe dollars to invest there. Now it only takes 2 Zimbabwe dollars to get one US dollar--in other terms the Zimbabwe dollar 'appreciated' against the US dollar which changed their 'exchange rate.'\n\nOn the surface this seems like great news for Zimbabwe, but now all of the American customers importing Zimbabwe goods had their prices jacked up by 100% because their 1 USD depreciated by 2 Zimbabwe dollars. If you're Zimbabwe and 50% of your customers are American, you're now losing a huge amount of those orders due to the currency shift. In practical terms that's factories and business closed and jobs lost. \n\nThe above scenario illustrates just one of a multitude of ways sudden fluctuations in currency prices can shock economies. Luckily countries have some tools to mitigate this risk which include Zimbabwe using the US dollar. If you'd to learn more try looking up currency pegging, reserves (of both domestic and international currencies), and how a country can change its own interest rate.\n\nTD;DR: Countries (and their citizens) need other countries' currency for international trade and investment. This creates a market with a supply of and demand for literallly every currency in the world--the prices of which are called exchange rates. Depending on the specific circumstances, sudden and/or sharp fluctuations in exchanges rates have the power to devastate economies. Countries like Zimbabwe use the US dollar to help counteract such changes. ",
"There are trade-offs for selecting different currencies.\n\nBy selecting USD, they trade control for stability. The US Fed now controls how much their currency is worth, but now the value of everyone's wages aren't dictated by the government's reputation/ political whims.\n\nMost countries select control over stability, but not all.",
"Demand for US dollars worldwide is like a huge export the US has, and increases value of dollars in spite of what some call irresponsible fiscal policy and spending. Additionally, reserve deposits of foreign countries in US dollars are also a huge export for the US. The US dollar is viewed as a superior safe haven currency, much like the Swiss franc but with wider availability, and wealthy Latin Americans and Chinese also hold personal interest -bearing deposits in dollars. ",
"It’s in the US’ best interest to have lots of people, companies, and countries use the US Dollar. The US can (within limits) change the value of USD, or the amount in circulation, to suit its own interests. This (and some related stuff) is called “seigniorage” (which is French for “we print the money everyone uses”), and it boosts the US GDP by about 2.5%.\n\nSeveral other countries also use USD as their currency, and all together those countries’ economies are too small to concern the Fed (who controls the money supply).\n\nIf the US economy is booming, but Zimbabwe’s economy is slowing (or vice versa), the Fed will adjust the number of dollars in circulation (and the standard interest rate) in the direction that benefits the US, but that will be the *opposite* of what Zimbabwe needs, and that’ll be very expensive for Zimbabwe.\n\nThis is why most countries have their own currency, and their own central bank. They want to adjust their money supply and interest rates to benefit their own economies.\n\nPS - Some exceptionally stupid people think God Himself decreed everyone would use USD for international banking, and if the US (for instance) were to blackmail a few countries (Iran, Syria, NK, maybe Russia) by refusing to let their central bank transfer money to/from the Fed, they’ll just have to cave to the US’ demands. But China would *love* to replace the US in this, and have everyone switch to their currency, so they could get that 2.5% boost rather than the US.",
"ELI5: If other countries keep the USD on hand, and it's the \"world currency\", why is the value of USD so much less in other countries?",
"Simple answer is that you can't ban people from using money you printed.\n\nAnd why would you want to? Having more people using your money is good for you. ",
"It does affect the value of the dollar. This is why US goods are comparatively expensive, and why the US will always have a trade deficit rather than the dollar decreasing in value naturally and making US goods cheaper.\n\nThis is totally fine by the US, historically; they have very purposefully made the dollar the World's reserve currency as it gives the US incredible leverage and power over world finances. The trade-off is that the US will almost per definition run a constant trade deficit. This is known as the Triffin Dilemma, is a well-known phenomenon, and is seen as a small price to pay for the incredible influence it bestows, \n\nHowever, Donald Trump either doesn't get international macro economics (he keeps thinking it works the same as micro-economics), or he has some reason to ensure the US loses one of the main reasons it's a super-powers.",
"Random aside, but in Zimbabwe 2 dollar bills are so common that many cashier drawers have a slot for them. Also, a lot of change was given in South African Rand",
"The US doesn't allow them. The Zimbabwean government decided that. These type of situations are often temporarily. The US has no say in it. The only problem is. Since the dollar isn't the official currency of Zimbabwe, the central bank of Zimbabwe has no say about it. So, you're stuck with the decisions of the FED (American central bank). Even if that isn't beneficial to Zimbabwe. If tomorrow the FED decides to destroy a lot of dollars or print a lot of dollars, this will influence it's value.\n\nThat's why everyone else isn't doing it. However, in the past countries did peg their currency to the dollar, when their own currency was too unstable. So, it has been done to prevent situations (hyperinflation) like in Zimbabwe. \n\nTL;DR: The US doesn't have a say in which government decides to use the USD. And no one else is doing it, because your central bank has no control on that currency. \n\nEdit: Just saw the rest of your question. We can't have one giant currency, because using the same currency often only works when you have similar economies. That's why people in the EU are even thinking about splitting the Euro into a North Euro and South Euro. Having one Eartho wouldn't work, because every central bank makes decisions based on the current situation the country is in. If you have a crisis (often saving is encouraged with high interest rates, and lending is discouraged), your central bank makes different decisions than when your economy is booming (often lending money to businesses and for consumption is encouraged, and saving discouraged with low interest rates). If everyone used the same currency and one economy was booming while the other was in a crisis, the central bank would be kinda stuck in the middle. Like it happened in Europe when Greece got in a crisis. In the past they would've been able to devalue their money or print more of their money. But they couldn't do that now, because the European central bank makes decisions based on the entirity of Europe. Since Greece has a smaller economy than Germany, Germany according to the central bank has the priority. So, they tried to help Greece by lending them money instead. \n\nTL;DR: One worldwide currency wouldn't work, because our economies are too different. It's like a one size fits all shirt. The fat person thinks it's too tight. The skinny person thinks that it's too loose. Only a few countries would really benefit from an international currency. The rest wouldn't. ",
"So lots of countries while probably not using the USD as it’s primary currency accept it for purchases. Belize being one I recently visited.\n\nOther countries with more obscure currencies and values while not accepting USD, will give the price in USD because most of the world knows how much a Dollar is worth as opposed to their native currency. ",
"A bit late to the game on this one. But, as a person who just visited Zimbabwe I had so many questions regarding their economy. So much so, that I decided to ask my current employer who has a podcast on the past, present and future of different countries. Anyways, they interviewed a guy named John Robertson, a native Zimbabwean and economist based in Harare who was very well versed on the economic problems facing Zimbabwe-- including the currency situation. Anyways-- check it out: [_URL_0_](_URL_0_) \n\n & #x200B;"
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cfpaaz | could you angle series of lasers and fire them into an object, mirrors, prisms, or something to focus and then combine them into one powerful beam? | If I bought 5 laser pointers from Walmart could I arrange them to fire their beams into a series of mirrors and lenses to focus the beams and then direct them at the same direction or into something to focus the beams into one big beam? Would this make them stronger, brighter, or more efficient? If one beam could cut through paper for example could five focus and cut through wood? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cfpaaz/eli5_could_you_angle_series_of_lasers_and_fire/ | {
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"No, because the reflection of light is by its nature reversible. If you shine a beam into a prism and measure its output angle, shining a different beam back into that same path will come out the same direction as the original input beam.\n\nIf you COULD convert multiple beams into a single coherent beam, it wouldn't be possible to reverse each portion of the output back into its individual source beams.\n\nYou can focus them so they all land on a specific point, but only at a specific distance, like how a magnifying glass has an \"optimum\" viewing distance from an object before it comes out of focus. But you can't make a magnifying glass, binoculars or telescope that never needs focusing."
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9zjnms | how are we able to bleed from anywhere on our body when veins, arteries, and capillaries are in set places? | Yeah, the title
How are we able to bleed from anywhere on our body (when cut/injured)? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9zjnms/eli5_how_are_we_able_to_bleed_from_anywhere_on/ | {
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"It's all connected in a closed loop. The force of the heart keeps it always moving through the veins and arteries. Now if there is a cut at any point in this series, the force of the circulatory system will push blood through the leak until it's stopped, or drained.",
"It's possible to poke a needle through several layers of skin and not bleed. Presumably you've had a papercut at some point too?\n\nBut beyond that, the veins you can see are the main ones, but they get regressively smaller in a fractal sort of pattern as they branch off from the main ones. If you cut a bigger vein you get more blood out of it.\n\nThink about it this way. Every single square centimetre of your body needs blood to operate. If it doesn't get that blood it dies, so the blood has to be everywhere.",
"Have a look at this picture of the circulatory system of the head from the body worlds exhibition \n\n\n_URL_0_\n\nThey effectively filled the veins and arteries with a chemical that solidifies, then removed the body from around it (I don’t know how!).\n\nThe result shows how many veins and arteries exist that carry blood around your body. It’s not like just one pipe going down your arm to your hand - it’s a vast, complicated network of veins and arteries that runs under the majority of the surface area of the skin all over your body. \n\nEdited: fix link and punctuation ",
"A adult human body have 100,000 miles of capillaries So they go almost everywhere because all cells need oxygen other stuff they need delivered and carbon dioxide and other stuff removed.\n\n"
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3m73xy | how do we know hellen keller actually learned to communicate and wasn't just making signals, gestures, etc. by conditioning? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3m73xy/eli5_how_do_we_know_hellen_keller_actually/ | {
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"well, for starters, she was also able to write in braille, and her writing was actually rather good. you should maybe read the autobiography she wrote. ",
"How do we know that YOU learned to communicate and aren't just making signals, gestures, etc. by conditioning??",
"In essence because she was able to communicate the content of her feelings, thoughts and ideas like others do too. She learned to write and speak too, even though her speech was hard to understand as she didn't hear herself. \n\nSo the question can also be thought like \"*how do we know any of as actually learned to communicate and we aren't just making signals, gestures etc. by conditioning?*\""
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f760cx | why can’t blood clots be undone with a really small cut where the clot is to have the clod get bled out? | Why can’t blood clots be undone with just like a really small cut to where the clot is to have the clot get bled out?
Full disclaimer I know that it sounds really stupid, but when I saw a video showing new technology that removes the clot by being inserted into the vein to remove clots it was all I could think about. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/f760cx/eli5_why_cant_blood_clots_be_undone_with_a_really/ | {
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"Do you mean cutting the clot? Or cutting the blood vessel next to the clot and have it “bleed out” of the body.\n\nThe first one requires far too much precision and if you’re going to touch the blood clot you might as well remove it.\n\nThe second one injures the blood vessel, so your body responds by clotting more blood at the injury site. Counter-productive.",
"A clot is a clot in the first place because it's blocking a blood vessel. It's like having a clogged sink drain. Cutting into the drain pipe below the clog doesn't do anything because the clog is still wedged in there. It's not going anywhere on its own. You have to actually remove the clot. Also, how would you propose \"making a cut\" in a blood vessel that's not directly under the skin or or somewhere inaccessible. To go back to my clogged sink example, that's like demolishing a wall to get to the sink to be able to cut into the drain pipe. That makes no sense. You don't demolish your house to get to a clogged drain, you use drain cleaner (clot busting drugs), or you snake the drain (put a tube in the blood vessel and break up/suck out the clot)",
"The clot isn't necessarily in a place where one could do that, but sometimes that's [exactly what they do](_URL_2_). The [catheter](_URL_1_) method is used for deep vein thrombosis, where you can't reach the vessel.\n\nAlso, clots are not going to just flow out, they're pretty solid. They need to be pulled out, or broken into smaller pieces (either mechanically, or with medication).\n\nETA: if you're not squeamish, [this Reddit post](_URL_0_) shows a clot being surgically removed from someone's pulmonary artery."
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658m28 | why mormons get made fun of while every other religion, if you looked logically, is just as laughable. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/658m28/eli5why_mormons_get_made_fun_of_while_every_other/ | {
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"Everyone gets made fun of. At the moment, Islam is ridiculed more than any other religion. ",
"The main reason is simply that it's newer. Mormonism has a well-documented history; most religions have the benefit of having historically obtuse origins that make them difficult to \"disprove\". Because we know the nitty-gritty details of Joseph Smith's life, it's easy for detractors to poke holes in it. It's much harder to reasonably argue against, say, the Bible, since we don't have great records of the time in which it was written (and a more cynical person may point out the 2000 years followers of the Bible have had to destroy and/or discredit any sources which conflict with the Bible's account). ",
"I'd wager it's because there's no real longevity to it really? Most major religions are ancient. Been questioned a lot longer",
"Having moved to Utah at age 8 because my mother suddenly got religion, and then been raised Mormon after that, I think their *lack* of logic contributes a lot to Mormons getting made fun of. But most of them are not moving targets, so there isn't much fun in ridiculing them.\n\nTheir total life envelopment and total willingness to ostracize you if you fall out of their graces is very similar to the Jehovah's Witnesses. Their lore and beliefs are weird on par with the Scientologists. Their fashion sense is basically Amish Chic, unchanged from when the religion was dreamed up in the 1830s. Seriously, in Utah many women wear dresses and hairstyles that I have only ever seen in Utah and in movies set in the 1800s. Teenage girls spending Saturdays getting ready for church on Sunday, with their hair in rollers, sewing new dresses and camisoles... I really despaired for a while there, age 12 or so, that I was going to go through my teen years having to date girls who were going out of their way to be frumpy. (Fortunately I became ostracized and homeless in rapid succession at age 14, living on the streets in downtown SLC, so *whew*... dodged that bullet.)\n\nA few years ago someone posted a meme about religions that went something like:\n\n\"Think of religions like a movie. The Torah is the first one, and the New Testament is the sequel. Then the Qu’ran comes out, and it retcons the last one like it never happened. There’s still Jesus, but he’s not the main character anymore, and the messiah hasn’t shown up yet.\"\n\n\"Jews like the first movie, but ignored the sequels. Christians think you need to watch the first two, but the third one doesn’t count. Moslems think the third one was the best.\"\n\n\"And Mormons liked the second one so much they started writing fanfiction that doesn’t fit with ANY of the series canon.\"\n\nThat last bit is one of those 'jokes' that I think might be funny if I hadn't been a Mormon as a kid but since I was, it's just a statement of fact.\n\ntl;dr: they dress weird, they believe weird things but are totally serious about them, they are really nice but have a bit of a Stepford Wives thing going on, and they are, in small enough doses, Mostly Harmless. So there are funny things about them, with little risk of (say) a Vatican rep or Tom Cruise showing up at your door if you make fun of them."
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atkemx | why do dynamical systems have natural frequencies, both mathematically and physically speaking? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/atkemx/eli5_why_do_dynamical_systems_have_natural/ | {
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"Well, what else would you expect? Dynamical systems are generally deterministic and repetitive in some sense. The physics of the system give its phase space a \"flow\", or vector field, at every point. The phase space encodes velocities, so the system can't go too \"far\" in any direction or else it would have more kinetic energy than when it started (you can apply similar reasoning to spatial components). This, in effect, confines the dynamical system to a finite volume in the phase space. Trajectories, following this vector field, cannot go endlessly filling out new regions of the phase space because of that finite volume. Like if you traced the path of a fish in an aquarium, it's invariably going to return very close to some point it was previously. A cyclic structure is forced on the vector field and determines what is essentially a \"minimum\" time it takes to come back near where you started. That's how you get a frequency naturally arising.",
"Let's break this down step-by-step:\n\n- All periodic waveforms can be represented as the sum of sine functions. This is termed a linear combination and the major virtue of such an expression is that you can handle each of those sine functions independent of one another.\n\n- Sine functions only have three characteristics: amplitude, frequency and phase. For our purposes, we won't be talking much about amplitude (how 'big' a signal is - loudness and brightness would both be expressions of amplitude). Frequency is inversely related to wavelength and refers to how often a signal repeats. Phase refers to the angular displacement from the origin - how much the signal is delayed in relation to the time it takes for a single cycle of the signal to occur.\n\n- When you add two sine waves of the same frequency, the outcome is largely determined by phase. If the phase is the same, they add constructively - the resulting wave is pure the sum of the two waves. If the phase is 180 degrees different, they interfere destructively - the resulting wave is the difference of the waves. In essence, the waves 'cancel out' each other. Between these phases, the waves are both constructive and destructive.\n\n- When you reflect a wave back on top of itself, the reflection of the wave will have the same amplitude and frequency. The phase will be dependent on where in the wave the reflection occurred. If the wavelength (determined by the inverse of the frequency multiplied by the speed of the wave) is an exact integer divisor of the distance between the start point of the wave and the reflection, it will reflect with 0 phase offset. Otherwise, it will reflect with some non-zero phase offset.\n\n- If you have a wave reflecting back and forth between two points, any non-zero phase offsets will rapidly add up to create a situation where virtually any reflected copy of the wave is 180 degrees out of phase from another reflected copy. If it reflects infinitely, this means the only waves left after all the cancellations will be the waves whose frequency has 0 phase shift in reflection - those waves who frequency translates into a wavelength that is an integer divisor of the distance between the reflection points. This concept is called 'resonance'.\n\nPerhaps the easiest way to see this is to think of a guitar string. It is anchored on both ends, so any mechanical wave running down its length will reflect back and forth between those two ends. The speed of mechanical waves (sound) in the guitar strings is fixed based on the material and the cross-sectional area. As a result, for a guitar string with a certain material and specific size, there will be a resonant frequency. If you reduce the effective length of the guitar string - such as by pressing it against a fret board - you will change that resonant frequency.\n\nBecause guitar strings are extremely good at transmitting mechanical waves and the body of guitars/fretboards are extremely poor, virtually all of the energy contained within the waves running down the string will be reflected back and forth.\n\nThese same sort of underlying principles govern most repeating phenomenon - wheels, springs, and the like.\n\nYou also obtain resonance from sampling frequencies. Consider the cruise control on your car. It reads a speedometer. If you're going too fast, then it will reduce your acceleration. If you're going too slow, then it will increase your acceleration. Each time you run through this feedback loop, your output (speed) is being fed back to your input (acceleration).\n\nThe rate at which this feedback occurs creates resonance. If you have some component which has the same frequency as your feedback loop, then its value will be exactly the same every time the feedback loop repeats. In contrast, components with a different frequency will have different values and - over time - those values will destructively interfere just like I explained above."
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cdtc40 | why isn’t every book advertised as a ”best seller”? and what’s the publisher’s criteria for choosing books that will be advertised as such? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cdtc40/eli5_why_isnt_every_book_advertised_as_a_best/ | {
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"The New York Times is a news paper which publishes a list of the books that sold the most copies in the previous week.\n\nAny book that appears on this list of best selling books is a NYT Best-seller.\n\nIf it appears on the first place in that list it is a #1 NYT best seller.\n\nIf an author has previously written a book that appeared on that list they can put \"from the NYT best selling author\" on the cover of his other books.\n\nThe New York Times actually has more than one list, splitting it up into categories like 'fiction', 'non-fiction', 'children's books' etc.\n\nSo each week there are potentially dozens of best-sellers and hundreds per year.\n\nMost books that get featured prominently in book stores and are advertised a lot fall into the category.\n\nThere are many other books that don't, but you won't here as much about them, because nobody wants to spend marketing money on books that won't sell very well."
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3e6gco | how dies windows task manager or my android phone know when a program isn't responding, and how is ending the task/force close different than exiting? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3e6gco/elif_how_dies_windows_task_manager_or_my_android/ | {
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"Android applications (and apps in other operating systems) operate on a message queue. The operating system sends messages to the app, such \"the user tapped the screen at x,y\" or \"the use clicked the back button\". The app has a single main thread that handles these messages. Whenever it reads a message, it executes the code that handles this message (if there is any) and when finished it will notify that operating system that the message has been handled, and asks for the next one.\n\n\"Application not responding\" happens when the application takes too long to handle a message. The OS will see that it didn't receive a notification that the message has been handled, and will realize there's something wrong.\n\nExiting the app happens from within - the app finishes up its tasks (saving data, closing connections, cleaning up files) and tells the OS \"I'm done\". The OS then removes the app from memory. Killing the app is forcing the app to shutdown from the outside - the OS simply destroys the app, automatically freeing any resources that it was keeping."
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1vqfnm | why are drug tests [for marijuana] still around? | If some states are starting to legalize it, how can other states still use drug testing?
If I'm an Idaho state resident and I test positive for marijuana use, isn't it possible that I *legally* smoked while I was visiting another state? And, if companies choose to test anyway, why would I be tested and potentially penalized when I'm not breaking any rules? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1vqfnm/eli5_why_are_drug_tests_for_marijuana_still_around/ | {
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"What does legality have to do with anything? Lots of things that are perfectly legal to do can also still get you legally fired. You can walk up to your boss and perfectly legally call him/her an asshole. And you'll get legally fired for this perfectly legal free speech.\n\nCompanies can ban drug use among employees in a lot of jurisdictions, regardless of whether that drug use was legal. In other jurisdictions, such testing isn't permitted. This has nothing to do with the status of marijuana, though.",
"You can get a breathalyzer test if they think you're drunk. If you can be drug tested, you signed an acknowledgment form at some point, probably."
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ejf1nx | how can a country openly assassinate a foreign citizen in a foreign country and it not be an act of war? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ejf1nx/eli5_how_can_a_country_openly_assassinate_a/ | {
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" > How can a country openly attack with intent to assassinate a foreign embassy and it not be an act of war?"
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2yh2rr | why does fat/grease leak through aluminum foil when i'm baking or roasting meat? | Say I throw a large piece of tin foil down in my baking dish before baking some delicious chicken breast. I'd do this to save time with clean up and not bake some ungodly tough crust into my glass baking dish.
Usually when I pull the meats out, there is a decent amount of fats or juices found on the glass beneath the foil where the meat was resting. I always leave a lip of foil overlapping the baking dishes edges, so how did it get through? Meat-based sorcery? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2yh2rr/eli5_why_does_fatgrease_leak_through_aluminum/ | {
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"I've baked a lot of things in foil-lined containers (or even on foil alone, college teaches us many skills).\n\nJuices don't leak through aluminum foil, plain and simple. IT just doesn't, aluminum foil is impermeable. One of the following must be true:\n\nThe pan wasn't as clean as you thought it was. Dried on grease was liquefied by the oven's heat and appears to have leaked through, when really, it was there all along.\n\nThere are holes/cuts/pokes in your lining, allowing oils to pass through.\n\nThere is a seam or gap allowing oil to pass through."
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1tgcrz | what's the net result of the arab spring? did it help or just make our world a little more chaotic? | Afaik Egypt is in a state of turmoil, Libya is still reeling and theres a civil war still going on in Syria. People are still protesting in Bahrain. Did the Arab spring do any good?? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1tgcrz/eli5whats_the_net_result_of_the_arab_spring_did/ | {
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"Well, it's still not entirely over yet, but you can definitely argue that good has come or will come of it. The Arab Spring has shown that people care about their governments and their fellow man. It has also shown how technology can influence how somebody views a fast-changing and politically charged uprising. It's been a learning experience for many so far.",
"The effect is still hard to see, it's definitly brought a bit more chaos. But there is one major change. The death of religious terrorism in the Middle-East. Yes I am aware that is a bold statement. You see for many years some people tried to change the region (and in fact the regime) by using terrorism/violence. It didn't work, now the protests from the Arab Spring got a much much bigger impact in a much much smaller timeframe. So they reached what terrorism never could, as so the succes of the protests killed the hope of change by terrorism and the use of terrorists. \n\nI am aware that civil war etc is horrible but I am talking just about the initial \"start\": the rallying of many thousands of people, religious terrorism never succeeded in that. Also I don't say terrorism won't happen again that is a much more complex story, this is just one side of the story I'm cherrypicking to give an answer on your question. \n\nSource: non-English speaking (sorry for some mistakes) master of International Politics"
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1n6bh9 | why is it often said that shooting on film is better than digital? | I have heard "All hail 35 mm" from time to time. Why is that people often say that film is better than digital? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1n6bh9/eli5_why_is_it_often_said_that_shooting_on_film/ | {
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"I think just a preference. It's like analog photos and digital photos. Analog just has more feel and texture, while digital has a more clean and slick look.\n\n(You should check out Side by Side _URL_0_ )",
"It really matter what your shooting, and what your shooting with. Film is usually better for speciality situation while digital is better generally.\n\nFirst of there isn't one type of film or one type of digital camera. Different times of film, respond to light in different ways. And different camera has different capacities. A crappy lens will ruin any shot, and a cheap sensor will to the same.\n\nSo for example Velvia which is a Slide Film has an extremely high colour saturation, making it beautiful for shooting sunset and landscapes, but at the same time it requires an incredible amount of light (Velvia has a speed of 50 which requires so much light you'd be hard presses to find a consumer digital camera that has a 50 ISO) and you really have to be careful with the exposure.\n\nAnsel Adams used extremely large sheet of film (8x10 inches) and a film called Tri-X to generate his images. Tri-X is a extremely contrasty film and the size of the film makes it extremely sharp and detailed. Most of the detail and imagery in his print would be difficult to capture using current film technology. By the same token setting up a 8X10 camera takes about the same amount of time as building a small lego playset.\n\nCompare that with say a $2000 plus SLR and you've got much more flexibility. The SLR will easily beat Velvia indoors, or when you have to deal with fast motion. SLR beat 8X10 in setup time by a mile. SLR is more forgiving with exposure, colour saturation, and temperature and will be excellent under most condition and far easier to fix.\n\n\nSo in the end it really matter what your shooting. If you shooting something really specific, you might need specific technology that is better for what your doing it. If you just want to shoot candid photo's, or even studio photography that doesn't need the extremes I mentioned then a digital camera is often the better choice.\n\n "
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fjehg0 | what is the blue light you see when you press above your eyelid? | And importantly, is it unhealthy for your eyes to do this?
I'm talking about when you press above your eyelid but still inside the eye socket, there is a blue circle on the bottom of your vision that follows the direction of your eye. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fjehg0/eli5_what_is_the_blue_light_you_see_when_you/ | {
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"text": [
"These are called phosphenes. Basically, you are putting pressure on the retina in your eye. When you put pressure on the retina, it makes your brain think you are seeing light, when in reality it is just a stimulus triggered by your finger."
]
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1m0ggh | what is the difference between billiards and pool? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1m0ggh/what_is_the_difference_between_billiards_and_pool/ | {
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"Billiards is a term used to describe all games played with cue-sticks and balls on a cloth covered table. Billiards includes games such Carom Billiards, Snooker, and Pool.\n\nPool is a specific billiard game. In pool, you win the game by pocketing all of your balls (which are numbered). There are different variations of pool, but they all follow the same general rules."
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3ns01n | why do people hate edward snowden if he blew the whistle on nsa surveillance? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3ns01n/eli5_why_do_people_hate_edward_snowden_if_he_blew/ | {
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"Two main reasons:\n\n- Some people believe that the loss of privacy is worth the increased security that domestic spying and the NSA provide. \n\n- Some believe that while whistleblowing about domestic spying may be justified, Snowden should not have told the world about our international spying mechanisms. \n\nI'm not saying that I agree with these arguments, just that they're the ones I've heard the most from Snowden opponents.",
"Watch the John Oliver segment on Edward Snowden. Most people have no idea exactly what he did. Many think that he sold military secrets, if they even know of him at all.",
"He blew the whistle on NSA surveillance which was a collective win for the world.\nBUT. He stole thousands of files, many of which were not relevant to the PRISM program, and handed them over to journalists. Among the files were information dealing with how tabs were kept on terrorists in foreign countries as well as countries that aren't exactly friendly with the West. This was a indirect blow to National Security and has affected how terrorists conduct their business. \n\nI'll probably get downvoted to oblivion for failing to bow down the St. Snowden"
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47dw35 | why do men have the option of length and waist on pants while women, who arguably could use these more often, do not? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/47dw35/eli5_why_do_men_have_the_option_of_length_and/ | {
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"Because men are basically rectangles. width and length. Women have more permutations of sizing because of their hips, so they have many more types of sizes, like misses, juniors, womens (body type), and petite and plus(size) variations of all those in different sizes."
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4c0c1b | do mirrors reflect radio waves the same way they reflect light? | Considering light is just electromagnetic waves and radio waves are just on the lower end of the spectrum does a mirror reflect them too or are they so low they pass right through mirrors? If radio waves pass through conventional mirrors can you make a mirror for radio wave and what would it be made out of? Additionally, at what point do conventional mirrors stop reflecting on both the top and bottom of the electromagnetic spectrum? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4c0c1b/eli5_do_mirrors_reflect_radio_waves_the_same_way/ | {
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"Anyone feel free to add but according to a PHD in physics: \n\"They do, and you've just never noticed. But if you have a big enough mirror and can point it toward a radio tower, you can test it out yourself.\nPoint this big mirror at the FM radio tower, and get out a portable FM radio. Now start at the mirror and start backing up from the mirror while listening. What you will hear is that at certain specific distances the signal will get really weak. This is because the reflection from the mirror generates a standing wave.\nAt the points where the incoming and reflected waves are opposite, you get a really weak signal.\"\nSource:_URL_0_",
"It all depends on what the mirror is made of. Most mirrors are made of a thin layer of silver on the back side of the glass, with another layer on top of the silver to protect it from corrosion. Some mirrors have a thin layer of aluminum, both of these are reflective in both the visible and microwave/radio wave spectra due to their low impedance (high refractive index). There are, however, technologies available to make highly reflective mirrors in the visible spectrum out of dielectric (high impedance) materials, that can be transparent to radio waves. \n\nThe basic reason comes down to impedance, which is basically akin to saying \"how hard is it for something to move through this media.\" Inside of metals and electric conductors it is very easy for electric charges to move, therefore we say it has low impedance. In air, we know that electric signals cannot propagate easily, so we say it is a high impedance medium. When two media have similar impedances, they are said to be \"impedance matched\", and electromagnetic waves can propagate through the \"boundary.\" It's when the boundary between two media has a large impedance mismatch, for example air and metal, that electromagnetic waves tend to reflect. \n\n",
"It depends on the kind of mirror. And by kind I don't mean which shape it has, but physical effect is used to do the actual reflecting. The mirrors you can buy come in two varieties: Metallic mirrors where the light is reflected by a electrically conducting (=metal) surface. And so called \"dichroic\" mirrors, where the reflection happens by letting the light interact of several layers of material that's more or less dense and where each layer has a certain thickness, namely one quarter wavelength of the light you want to reflect.\n\nMetallic mirrors will reflect every kind of electromagnetic radiation where the electrical \"pixies\" in the metal (= electrons) can move around quicker than a certain electrical wave would throw them around (this is called the plasma frequency, the details don't matter). The takeaway is that a metallic mirror can reflect light up to a certain frequency and light with a shorter wavelength can start to pass through. Also depending on the metal some wavelengths of light will be absorbed more than others (think about how gold has this golden color, silver is slightly yellowish, aluminium is more or less neutrally white, copper is reddish and so on).\n\nWith the dichroic kind of mirror there's only a rather small band of wavelengths that is reflected, namely the wavelengths which are around 4 times the thickness of the layers that make up the mirror. This property of dichroic mirrors makes them suitable as an optical filter. Radio waves are much, much longer than your typical mirror is thick and hence will usually pass through such a mirror without problem.",
"RF Engineer here... \n\n**Short answer:**\n\nYes.\n\nAny decent conductor will reflect/absorb lower frequency electromagnetic radiation.\n\nOn the higher end, the electromagnetic waves will be able to penetrate your mirror. X-rays and gamma-rays render your mirror is pretty well useless and you'll need a conductor thicker and denser like lead (or thorium or depleted uranium if you're crazy enough).\n\n**Better answer:** \n\nYes, most electromagnetic radiation (EMR) will be either reflected or absorbed by nearly all conductive materials (the better the conductor, the better the reflection/absorption). A mirror is just glass with a thin layer of silver deposited on the back. And silver is a pretty damn good conductor. And you are correct to assume that conductors will not reflect RF across the entire [electromagnetic spectrum](_URL_3_), though they are the best reflectors of EMR. Silver is commonly deposited on the inside of RF waveguide tubes because of it's good conduction and lack of oxidation.\n\nBut I should note, mirrors aren't truly the only thing that reflects light. In reality, all solid materials reflect some amount light. If they didn't, you couldn't see them (by definition, I guess). Mirrors are special only because they don't scatter the light as they reflect it. Transparent glass will reflect light given an obtuse enough angle. And even air can reflect light. Ever see a reflection that looks like a pool of water on the concrete while driving on a hot day? That's actually the hot air rising off the concrete meeting a cooler layer of air just above it. So even air can reflect light given the right circumstance. (Ok fine, it's actually refracting... haters.) White light shining on a pigment reflects light of that wavelength and absorbs the rest. So everything you can see around you reflects light, not just mirrors. Kinda obvious now, right?\n\nMost of the RF around you (at frequencies lower than light) is reflected at least a little by a wide range of materials. Conductive materials are the best and will reflect or absorb pretty much all of them. Those little metallic dots on the window of your microwave (which is radiating at a frequency of 2.4GHz) reflect the RF energy back into your food and away from your eyes. This is actually an example of a [Faraday cage](_URL_2_) at work. Faraday cages need not be solid to reflect or absorb lower frequency RF such below 1 GHz. But a conductive mesh with a weave of 3 cm will allow nearly all RF above 10 GHz to appear transparent. The higher the frequency, the tighter the weave needs to be. Above 100 GHz, you'll need to start using solid metals to reflect the EMR (like the silver on your mirror). Any holes in the Faraday cage's shielding must be significantly smaller than the wavelength of the RF.\n\nThere are a number of technologies that you're no doubt familiar with that exploit metals' ability to reflect lower-frequency RF (than light, that is). Radar works on the RF reflection principle, 'painting' aircraft with an electromagnetic signal and 'seeing' reflections bounce off the aircraft, calculating it's range based on the received signal transmit time. For the trivia junkies, it takes 12.36 microseconds for that radar signal to hit an aircraft and reflect back to the radar for each mile it is from the aircraft (aka [radar mile]( _URL_0_)). Police radar does the same thing (these are in the low end of the EHF or [Extremely High Frequency](_URL_4_) band, between 30-80 GHz).\n\nSatellite dishes feature a curved conductive reflector to gather more RF for far away communication (the antenna is actually that little bit in the front, not the dish). In this case, the reflector acts like a lens. The bigger the reflector, the more RF can be absorbed by the antenna. Remember that gigantic one at the end of GoldenEye? Yeah, that's a [real thing](_URL_1_).\n\nThose millimeter-wave scanners at airports (which radiate at the highest end of the microwave spectrum at around 100 -300 GHz) reflect from conductors but are effectively transparent to clothing and will go through flesh pretty ok. Please note that this is non-ionizing radiation and therefore not a health concern.\n\nAt the higher end of the spectrum (above visible light), electromagnetic waves will go right through conductors. EMR reflection/absorption for a relatively thin conductor begins to trail off around 30 petahertz (wavelength 100-10 nm), the high end of the UV spectrum. A silver mirror will only reflect ~70% of the UV light at this frequency. You've probably experienced this yourself. Ever have an X-ray and noticed the lead apron? There's a reason that X-ray aprons are made of lead a few millimeters thick and not something lighter and more conductive like copper. Lead is particularly good at blocking these frequencies of EMR because of its high density. You would need 6x as much steal to equal the EMR shielding of lead.\n\nNow as you start approaching the gamma-wave region of the spectrum (which is somewhere between 100 picometers and 10 femptometers, which I guess is as high as we can detect), you'll need > 1 cm of lead to shield just 50% of the energy. And that's just at the higher end of X-rays. Lower frequency gamma-waves, you would need a 5 foot thick lead-lined box buried 100 ft into the ground (I'm guessing here, gamma-waves aren't really a thing we come across in the engineering world). It's probably not even worth talking about the hella-high regions of the gamma-wave frequencies, as the energy needed to produce this radiation can really only be achieved by Pulsars and Supernovae."
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"https://en.wikipedia.org/wiki/Arecibo_Observatory",
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"https://en.wikipedia.org/wiki/Electromagnetic_spectrum#/media/File:Electromagnetic-Spectrum.svg",
"https://en.wikipedia.org/wiki/Extremely_high_frequency"
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4aqafc | what exactly is a "bot"? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4aqafc/eli5_what_exactly_is_a_bot/ | {
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"A bot refers to a computer program doing something that's intended for humans to do, like playing games, visiting websites, registering for websites, writing comments or whatnot.\n\nEliminating them is difficult because they are essentially pretending to be humans. Sometimes they use separate bot user interface, so if someone uses that, the server knows its dealing with bot, but sometimes bots don't do that, and it can be quite difficult for service provider to know if someone is a bot or not. Captcha is an example of a system designed to figure out if someone is a bot or not, and to prevent bots from accessing certain kind of content, like registration forms.\n\nReddit for example has plenty of bots doing valuable work, like for example this subreddit has a bot that checks each comment against certain rules and removes it if it seems to be infringing subreddit rules. They're not inherently bad or good, they're just tools that can be used."
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1olf0t | what is a scientific chimera (not the greek mythology version) | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1olf0t/eli5what_is_a_scientific_chimera_not_the_greek/ | {
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"First, the most extreme type - Tetragametic chimerism \n\nTetra = four \n\nGametic = relating to eggs and sperm. \n\n\nA woman is pregnant with twins, two of her eggs (ova) have been fertilised with two of her partner's sperm. \n\nThese fertilised eggs are called zygotes. \n\nNormally we would expect these zygotes to develop separately as two individuals, but instead the zygotes merge to become one individual embryo.\n\nHence tetragametic 1 sperm+1 sperm +1 egg +1 egg = four gametes \n\n\n This can also happen at the blastocyst stage when the developing infant is still only about 100 cells big. \n\nThis embryo will have some cells with DNA from twin A and some with DNA from twin B. That is to say, genetic testing will reveal that this one person was once two people. \n\nThat's the most extreme type and incidences of it in humans recorded in the medical literature are very, very rare, but it's likely that cases aren't detected unless there is occasion for a person to undergo genetic testing. Even then it can be missed as whole organs may have the DNA from just one twin, whilst DNA of the other twin resides elsewhere in the body. \n\nA less extreme type is microchimerism where you have some cells with DNA from another individual. \n\nMost people have some cells with DNA from their mother during childhood, these were cells that migrated through the placenta and became part of the developing infant. \n\nMarmosets (a cute little monkey) are usually born as fraternal (non identical) twin pairs (sisters or brothers) and it is normal for each to have some organ tissue or blood cells or gametes with the DNA of their twin, because they share a blood supply during development stem cells can migrate easily from one to the other. \n\nDetecting cases of Chimerism where identical twins were fused is very tricky - so the vast majority of cases in the literature, whether looking at humans or animals, are about fraternal twins - simply because they are genetically distinct enough that the differences in their cells stands out. \n\n\n"
]
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[]
] |
||
byko4b | why can't the body defend effectively against ebola? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/byko4b/eli5_why_cant_the_body_defend_effectively_against/ | {
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"One known mechanism is that the virus can synthesise a protein which inhibits the activation of an important cell in the inflammatory response (neutrophils), blunting the initial immune system's response. There are probably other mechanisms. The fact it replicates so quickly is also a factor.",
"It can, eventually. The survivors are mostly virus free. The reason ebola is so deadly is that in humans it's faster than an unprepared immune system, and people die before they have time to beat the virus.\n\nIt's kind of by accident; the virus is trying to live quietly in its rodent host's kidneys, and tweak the kidneys just enough to escape into the urine so it can spread to other rodents. Because ebola's usual hosts are accustomed to fighting back, it's too strong for unprepared humans. All the haemorrhagic fevers (like hantavirus in the US) work similarly."
]
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[],
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||
4tkp0a | why is there a distinct smell after a female uses the toilet? | So I grew up with 3 females in my house (mum and two sisters) and I could always tell whether it was a girl or a boy who had used the bathroom last in the house. It always had a sort of mild but strong smell if that makes sense.
Now I always had thought that this was only a thing in my family. But after just getting a female roommate who shares my bathroom, I noticed the EXACT same smell.
Has anyone else every noticed this smell or am I a psychic? What exactly is it about women that produces this characteristic smell and do men have something similar? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4tkp0a/eli5why_is_there_a_distinct_smell_after_a_female/ | {
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"text": [
"Why are you the pee whisperer? I have never heard anyone else talk about this concept, not noticed it myself.",
"It might have to do with her period. I have noticed it. I am not aware of men having something similar, but then again, I wouldn't know because I would be carrying it around with me.",
"Some people have a far better sense of smell than others. For example, I can tell if a woman is on her period from about six feet away.",
"I do know the smell your talking about, its not a pee or poop smell. But its definitely there lingering in the room, like female ass crack smell. Good question! Maybe its pheromones. \n ",
"My best guess would be a different hormonal and pheromone balance in women, which could make urine smell different as they are excreted.",
"I have noticed this at times, too. I can usually tell if a woman or a man has used the toilet. I'm guessing it's vaginal? Perhaps it's the lingering smell from a bit of sweat from the groin being out in the open while women pee or something? Since they tend to undress their bottom half completely and sit down to use the toilet, while men dont? ",
"You just brought back a very potent childhood memory for me - I noticed this same smell when my mom would pee while I was taking a bath. It was different from anyone else in my family. I can't smell it anymore, I assume because my pee smells the same now!\n\nIt's not a vaginal smell, it's definitely about the chemical makeup of the urine. I'm guessing it's hormonal, but I'm not a pee scientist.",
"I thought I was the only one who could smell it! \n\nI first noticed it as a kid with my mom and aunts. Then once women entered the picture in college and adult life. I smell it all the time at work because we have unisex bathrooms. \n\nI think it's just a naturally occurring vaginal smell. It's not bad, just different. \n\nStrangely enough, I can also smell when a woman is \"aroused.\" Gift and a curse, that one. "
]
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[],
[],
[],
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[],
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19e7j9 | why do some games launch as exclusives on a particular console? | How can the make as much (more?) than if they launched on all the consoles? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/19e7j9/eli5_why_do_some_games_launch_as_exclusives_on_a/ | {
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"text": [
"It takes money to release onto other consoles, as you have to modify at least some of the code in the game no matter what since it's a different system.\n\nIt's also possible they are paid some amount by the console maker to make it exclusive, or the developer is actually the console maker, or is related to it (Halo is an example of this).",
"The big consoles since Nintendo NES have always had what they call a \"Killer App\". And most consoles that fail have failed to bring their own \"Killer App\". Nes would never have become huge if you could play Super Mario Bros on the ATARI.\nSystems that seem good on paper but bombed never had the \"must buy\" game. Jaguar, Lynx, CD32, CDTV, SEGA CD, Dreamcast (yes it had excellent games, but it failed to market them) all failed because people never pictured themselves sitting at home playing those games. It failed to make people to dream of playing them.\n\nSo the big names either makes their own game, OR they write contracts (probably paying a lot of the development costs and therefore carrying much of the risks) with other companies on games they perceive could be a future hits. Because all systems need their own \"system-sellers\".\n\nEventually this will stand on its head with the new Steam-BOX. But only the future will tell."
]
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[],
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] |
|
69exkm | what are the differences between engines with same engine power(hp) but different volumes(cc). | What are advantages or disadvantages of 2200cc 150kw engine compared to 3000cc 150kw engine? Both diesel engines. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/69exkm/eli5_what_are_the_differences_between_engines/ | {
"a_id": [
"dh62lb7",
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"text": [
"Engine cc refers to an area of volume, the raw size that a particular part of the engine is.\n\nHP refers to how much actual power that engine can produce.\n\nSo if an engine is built badly but is huge, it may have lower hp than an engine that is built well but is smaller.\n\nIn the 60s there were 8000 cc engines being built that were so inefficient, a modern 1600cc engine actually has more pulling power than it.\n\nGENERALLY .. its easier for engineers to get a higher HP, the larger that bit of an engine described in CC is.",
"An engine that is larger for a given horsepower will *usually* be less extremely tuned, and will usually last longer. \n\nAs much as it is fun to engage in Jeremy Clarkson style bashing of old American engines that make 120 horsepower out of five liters, it's not beyond reason to tune those same engines to make 400-500+ horsepower. \n\nThey also tend to last longer when they aren't being stressed. 200 thousand miles isn't difficult to achieve on those old engines. "
]
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[],
[]
] |
|
40p787 | how does the law of gravity affect gasses? | I know it's probably similar to how the other states of matter are affected, but it seems as though gasses, primarily smoke/water vapor defy gravity and movie freely against it. Also how high would the force of gravity have to be in order for an element in its gaseous state to be pulled towards an object? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/40p787/eli5_how_does_the_law_of_gravity_affect_gasses/ | {
"a_id": [
"cyvz9rk"
],
"score": [
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"text": [
"Gasses seem to defy gravity because they are lighter than another gas that is already present: air. In a vacuum gravity would pull a gas downward, and it still pulls smoke and helium downward as well, its just that the bouyancy force is stronger. Think of us on land as living at the bottom of a huge ocean of air and its easier to conceptualize. (Side note, plenty of gasses are heavier than air and will flow downward)"
]
} | [] | [] | [
[]
] |
|
o4daj | what are the confidentiality agreements a person has with their doctors, lawyers, and psychologists | I volunteer in a hospital, and I'm curious has to how they all differ. I'm a little hazy on the Doctor one, but I have no idea about the Lawyer and Psychologist agreements. If you can, try to go into situations where a person tells one of these professionals that he/she will make a threat against someone, attempt murder, confess to illegal activities, threaten suicide, etc...
Specific question: What happens if a lawyer sees a man and his wife later questions the lawyer if her husband had come to see him? Does the same answer exist for doctors and psychologists? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/o4daj/eli5_what_are_the_confidentiality_agreements_a/ | {
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"Doctors and Psychologists are bound both by professional ethics rules and federal law (HIPAA) from disclosing information about you and your health both during and after your care with them. This agreement to privacy is assumed and automatic and includes protecting info like: your chart notes, lab results, tests ordered, your history, and the very fact you are even being treated. It is a crime for any health care worker to even acknowledged your presence under treatment to anyone or even look up your data without having a specific medical reason to do so. Many docs/nurses/secretaries have been fired for looking up data on family and friends (even harmlessly). \n\nThere are exceptions to this, such as: any info you waived a right to (ex. most offices make you sign a form allowing them to release any an all info to insurance companies about your care so the doctor can get paid), emergencies where you cannot make informed decisions and need a proxy to choose for you, health information/data not linked to any identifying information (ex. I can use all your health metrics in my study on heart disease, as long as I take steps to ensure nothing is traceable to you), times where information my be life threatening to yourself or others (\"Doc I'm gonna kill someone tonight\" is not covered under HIPAA), and any times you agree to share info (this can be in both writing like an authorization to release a record or in person such as allowing a spouse to be present during the doctor's physical examination). \n\nLawyers I have less understanding of, but from what I know, they have a privilege of confidentiality with their clients during and after services. Simply put, a Lawyer cannot be called in a court case to testify against his or her client. This is necessarily to provide the accused with a full defense, other wise anything said to their own lawyer can become evidence. I may be wrong, but this privilege is protected by professional ethics only and not by law (ex. If a lawyer tell a reporter \"oh yeah my client is totally guilty\" he will be disbarred from the profession and sued by his client, but cannot be fined or taken to jail). I also know that the 'attorney-client' privilege does not cover potential crimes, so you also cannot say \"Counselor, I'm going to kill someone tonight.\" \n\nMaybe a law student can clarify the legal stuff here.",
"I suggest you post the lawyer part of this question to [/r/explainlawlikeim5](/r/explainlawlikeim5). Lots of good folks there would be happy to answer."
]
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[],
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] |
|
3eox4f | how much damage would a nuclear weapon the size of a bullet do? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3eox4f/eli5_how_much_damage_would_a_nuclear_weapon_the/ | {
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"None. You can't make a nuclear weapon the size of a bullet. \n\nTo make a nuclear weapon, you need enough weapons grade fissable material to create a fission bomb.\n\nFusion bombs still need a fission stage to cause the fusion.",
"According to [this article](_URL_1_), \"*The practical maximum yield-to-weight ratio for fusion weapons (thermonuclear weapons) has been estimated to 6 megatons of TNT per metric ton of bomb mass (25 TJ/kg).*\" This is just a rough average, and newer bombs are more efficient, but that's what we'll work with here.\n\nFor the bullet nuke, you'll need to use the largest bullet possible. You're going to need to pack all you can into that little bullet, it's going to weigh an awful lot because of the material used, and you're going to need to fire it a very long distance. Let's use [this freak of nature](_URL_2_) called the JDJ.\n\nThe JDJ fires a .905 Caliber bullet that normally weighs 2400 grains. For comparison, the common .22 Caliber bullet comes in between 32 and 40 grains depending on the type (lead/hollow-point/etc), the 5.56x45mm(.223 Caliber) used by the US military (and by a lot of hunters to take down deer) weighs about 62 grains, the .44 Magnum (Do you feel lucky?) goes from 240 up to 340 grains, and the .50 BMG is a massive 647 to 800 grains.\n\nWhat does this all mean? It means that normal bullets are very light. That big 800 grains is only 52 grams, or about 1.8 ounces. Which means that the monster at the top, the .905, comes in at an astounding... 5.48 ounces. \n\nWhich comes out to 0.0001553554 Metric Tons.\n\nA bit of napkin math (feel free to correct me anybody, please?) says that the nuclear bullet you've just fired will yield an explosion equal to... about .9 kiloton. [This interactive map](_URL_0_) tells us that's about enough to completely destroy... a city block. And knock over the buildings for another two block radius.\n\nAssuming you could actually make it work. In reality, the bullet is just too small to work. The smallest Nuke we have today is still the size of a large backpack."
]
} | [] | [] | [
[],
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"http://nuclearsecrecy.com/nukemap/",
"https://en.wikipedia.org/wiki/Nuclear_weapon_yield",
"http://www.theblaze.com/stories/2012/02/03/want-to-see-the-worlds-biggest-caliber-rifle-in-action/"
]
] |
||
4aqunp | turbofan vs turbojet vs scramjet? | What's the difference? They all use fans of some sort, I think. (Former post got deleted because the mobile Reddit doesn't auto include ELI5) | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4aqunp/eli5_turbofan_vs_turbojet_vs_scramjet/ | {
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"All jets use the compression of incoming air and the mixing of it with fuels to generate thrust from the expelling of the exhaust gasses to generate thrust. \n\nA [turbojet](_URL_0_) uses a turbine to compress the air prior to the injection of fuel to generate thrust. Comparable turbines are used to feed compressed air into internal combustion engines to increase their power output. The turbojet engine is based on a rotating shaft that harvests power from the expelled exhaust to power the turbine to compress the intake air. All of the thrust is produced by the expelled exhaust via [Newton's third law](_URL_2_).\n\nA turbofan engine puts some of the torque of the rotating shaft to work operating a [ducted fan](_URL_1_) that provides aditional thrust. The air passing through the ducted fan envelopes the turbojet engine at the center of the tube.\n\nA scramjet is an entirely different thing. It compresses the incoming air via the shockwave its air intake creates in air at very high supersonic speeds. It has very few moving parts compared to the other designs.\n\nYou can take off from the ground, starting at an airspeed of zero using either of the two other types of jets, military and commercial jets do it all the time, but the scramjet is inoperable at subsonic speeds. \n\nIt requires very high, hypersonic, speeds to operate at all, this is rocket boosted NASA level stuff.",
"Scramjets don't use fans, but we'll get to that.\n\nThe fans are used to compress the air. That makes the fuel more efficient, since there's more oxygen tightly packed around the fuel when it ignites.\n\nTurbo**fans** use that fan action to accelerate air passing through a part of the engine that is *not* included in the combustion. That's the light pink area in [this picture](_URL_1_) around the outside of the engine. That part, called the *bypass* contributes to extra thrust without using fuel, but it also slows down the thrust coming directly from the engine. The point is that you have a much more efficient engine at the cost of some raw power.\n\nTurbo**jets** do not have that bypass. All of the air is funneled into the engine to be ignited. Turbojets generally compress the air a lot more and produce a lot more thrust at the cost of fuel. Turbofans go kind of fast but save fuel, turbojets go really fast and suck down fuel.\n\n(Side note: there are also turbo**props**, where the spinning action of the shaft that normally is used to compress the air going into the engine is also used to power a drive shaft to, say, propellers. This how most helicopters produce thrust: jet engines that turn the props. You get a *lot* of fast rotation this way with a much lighter engine than if you tried to use internal combustion engines, but very little thrust out the back, as most of the energy is used to turn the drive shaft. EDIT: [picture](_URL_2_))\n\n**Ram**jets do not have a rotating fan. A fan couldn't rotate fast enough to compress the air properly. Instead, a specialized cone is used to compress the air just through the force of the engine moving forward. Basically, the engine goes *so fast* that it compresses the air *by going faster*. Ramjets can't function at lower speeds: another engine (or another aircraft entirely) has to get them up to speed so the air going in compresses enough. Once they go, though, ramjets go *really damn fast*. Edit: [picture](_URL_3_)\n\n**Scram**jets go even faster. They go so fast that the air blowing through the ramjet engine *doesn't have time to ignite* before it's already blown out the back. Ramjets have a combustion chamber before the nozzle, a place where the fuel mixes with air and ignites. Scramjets don't. They're designed so the intense pressure created by compressing the air heats it up enough to ignite fuel. So there is no combustion chamber - the air comes in, immediately ignites, and fuel is dumped in as it blasts out the back. Scramjets are what happens when someone looks a ramjet and says, \"The laws of aerodynamics and physics don't allow an engine to work at speeds higher than what a ramjet is capable of. I'm going to make one do it anyway,\" and it works because when the universe tries to stop you, you just outrun it. Like ramjet engines, scramjet engines don't work at low speeds. EDIT: [small picture](_URL_0_)\n\nEDIT: Clarification and a humorous quip."
]
} | [] | [] | [
[
"https://en.wikipedia.org/wiki/Turbojet",
"https://en.wikipedia.org/wiki/Ducted_fan",
"http://csep10.phys.utk.edu/astr161/lect/history/newton3laws.html"
],
[
"https://upload.wikimedia.org/wikipedia/commons/thumb/2/22/Scramjet_operation_en.svg/300px-Scramjet_operation_en.svg.png",
"https://upload.wikimedia.org/wikipedia/commons/thumb/7/77/Turbofan_operation_lbp.svg/2000px-Turbofan_operation_lbp.svg.png",
"https://upload.wikimedia.org/wikipedia/commons/thumb/2/29/Turboprop_operation-en.svg/2149px-Turboprop_operation-en.svg.png",
"https://upload.wikimedia.org/wikipedia/commons/thumb/6/6c/Ramjet_operation.svg/2000px-Ramjet_operation.svg.png"
]
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|
3dze71 | should you leave the door closed or opened when using a fan to cool your room? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3dze71/eli5_should_you_leave_the_door_closed_or_opened/ | {
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"A fan only circulates the air inside, so the temperature in a closed room shouldn't change too much.\n\nIf you have a window in that room and the outside air is cooler, maybe crack open that window.",
"A fan does not cool, it just moves air around which makes it seem cooler as it enhances evaporation/heat transfer. Depending on if it is warmer on the other side of the door it could thus make sense (if its cooler outside) or be actually bad (if its warmer)."
]
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[],
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||
2r3kxx | how does signing the merchant's receipt after purchasing with a debit/credit card add to payment security? | Surely the PIN itself should be enough? What is the benefit of signing? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2r3kxx/eli5_how_does_signing_the_merchants_receipt_after/ | {
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"The benefit is to the merchant. The signature can help to prove you were really there and approved of the transaction.",
"If the receipt is not signed and its a fraudulent transaction, the merchant has to eat the cost. If the receipt is signed, the bank will have to eat the cost. When a merchant doesn't have you sign (gas station, starbucks, etc.) it's due to the fact that they have chosen to make the transition quicker and are willing to eat the cost if the transaction is fraud. \n\nStarbucks doesn't really lose much if they have to pay up $4.50. But best buy wouldn't want to absorb a $2000 television, so they make you sign. Ultimately it's up to each company to choose what to do, but by having it get signed they are protected. "
]
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[],
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|
6zju4l | most bridges are made out of concrete but how do they pour the concrete onto the bridge? | Do they pre make slabs first and assemble them? Otherwise how would they pour concrete in mid air without tonnes of supports? Please help I'm really thick. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6zju4l/eli5_most_bridges_are_made_out_of_concrete_but/ | {
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"text": [
"Two options depending on the size of bridge and depth of water. \n\nThey can use a piledriver machine that shoots big metal rods into the ocean floor. \n\nMore often they build a coffer dam and pump the water out of it. Then they lower workers down into it and they lay concrete, let it dry, and pump the water back in.",
"The chinese build them like [this](_URL_0_).\n\nThe concrete sections are made elsewhere, carried in, and lifted into position.\n\nThe concrete pillars are also made in sections and stacked with reinforcement/connectors between sections."
]
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[],
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"https://www.youtube.com/watch?v=TxN58jfAOIE"
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dbgxd4 | why is eating sugar and carbs more responsible for belly fat accumulation than protein and fat? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/dbgxd4/eli5_why_is_eating_sugar_and_carbs_more/ | {
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"text": [
"More or less - it's not. \n\nFor a variety of reasons, with the cheap and widely available foods availble to Americans, it's usually far easier to overeat carb-heavy foods (especially those full of simple sugars) than it is protein or fat-heavy foods, even though fat is more calorically dense than carbs or protein, and protein is just as calorically dense as carbs. Calorie for calorie, it doesn't matter if it's carbs, protein, or fat in the long term.\n\nAdditionally, different types of macronutrients don't end up in specific areas of the body when stored as fat - this relies on gender, and genetic factors."
]
} | [] | [] | [
[]
] |
||
4qo3xd | why is the high school graduation rate so low in the u.s.? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4qo3xd/eli5_why_is_the_high_school_graduation_rate_so/ | {
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"text": [
"80% is low? Or did you not do your research before making the post?\n\nThe rate (on average) in 2012-2013 was 81%, though different groups had different rates.",
"People don't value their education. Many students simply don't care. School is almost more of a super cheap daycare system for them until they're old enough to drop out. \n\nThe problem stems from the parents, in my opinion. Many of them are working jobs that don't require a diploma, and therefore don't value their own education. This idea passes down to the kids, and they drop out when they can. \n\nThere are still plenty of parents that want the best for their kids, and push them towards education that are in those same low paying jobs, but many don't care."
]
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[],
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8h91j7 | if clinical depression is caused by inadequate levels of serotonin or dopamine why can’t we just serotonin or dopamine supplements. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8h91j7/eli5_if_clinical_depression_is_caused_by/ | {
"a_id": [
"dyhyauw",
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"text": [
"It’s rarely the case that something you eat can make it all the way into your brain in it’s ingested form. It’s actually a good thing when you think about it because we eat a lot of things that shouldn’t be interacting with our brains. Not to mention that the levels of serotonin and dopamine are very finely tuned and it would be easy to overdo it if you could take them orally. ",
"Because dopamine and serotonin are much deeper than \"happy\" chemicals. In fact, the serotonin you have flowing in your blood does not cross the blood brain barrier. We can't just feed people those hormones without a lot of other processes going whack. This is why antidepressants are directly neurological, stimulating your neurotransmitters to inhibit reuptake (SSRI specifically) of them, so they sit between activating their connection more. These drugs are specific to which types of connections they target, at varying levels of intensity."
]
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d4xwk5 | what's the point of credits and debits in accounting? i don't understand how the system of increasing debits and credits to equity/assets/revenue/liability/expense etc. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/d4xwk5/eli5_whats_the_point_of_credits_and_debits_in/ | {
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"text": [
"They are a way to insure that everything balances. Bookkeeping can be an exact science because if it is done right it all balances and life is good. \n\nBasically every transaction will affect 2 accounts at least and debits and credit should always equal.",
"Accounting was invented before mathematics had developed into its current form. One of the things missing from mathematics was the concept of zero and negative numbers. So in order to note which direction the money is going accountants are using debit and credit. Debit being the money going into an account and credit being money going out of an account. Accountants have recently started to use positive and negative numbers instead of debit and credit however this can be confusing to some as they take negative income and results to be a bad thing. It can also be dificult to calculate things like revenue without the help of computers.",
"Don't worry about not getting it intuitively - it isn't intuitive!\n\nWhat some others have said above about debits being a decrease/bad and credits the opposite is wrong. It depends on the account as to which way it moves when debited.\n\nA handy initiliasm is, that to increase an account, it follows this:\n\nDebit\nExpense\nAsset\nDebtor\n\n\nCredit\nLiability\nIncome\nProvision\nShares\n\nIt spells DEAD CLIPS.\n\nE.g. if you increase your cash sales (credit income) you increase (debit asset) your cash.\n\nGenerally trainee accountants take 3 months or so of practice to really get it.",
"One thing to remember about this kind of accounting - you shouldn't think about 'debit' and 'credit' as having any kind of definition. Think of it like 'transaction entry type A' and 'transaction entry type B', and with the rule that A and B must equal in any transaction.\n\nA second issue is that we are introduced to the terms, 'debit' and 'credit' when we hear about bank accounts. But these are the bank's accounts, not yours; so they reflect what is a debit and credit from the bank's position - savings or debit accounts are a debt from the bank's standpoint, money they have to pay back to you; credit card accounts are assets to the bank, because they expect you to pay them. This means that what we learn about the meaning of 'debit' and 'credit' is completely wrong.\n\nAnd even getting this straight doesn't help you understand how this works on income, expense or equity accounts.\n\nSo, Transaction Entry Type A and Transaction Entry Type B. Liability, Income, Equity are credit accounts (credits are a L.I.E), Assets, Costs and other Expenses are debit accounts (because debits are actually A.C.E)",
"You'll love double-entry bookkeeping once you get the hang of it. That's what makes all the other bits 'click' and make sense.\n\nAs some other people have indicated, a credit to one account is a debit to another and vice-versa and that's your double-entry and what makes it all balance out and make sense."
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eu45bh | why looks like most of the dangerous illnesses came from asia? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/eu45bh/eli5_why_looks_like_most_of_the_dangerous/ | {
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"Most of the people on earth live in Asia. This means that it is more statistically likely that diseases would originate from there. It's also the origin of a lot of trade which can spread diseases elsewhere more easily compared to say if a new virus mutated on a deserted island.",
"I'd say it's a generalization.\n\nHIV aids came from Africa. Zika was from originally Africa I think, but the 2015-2016 outbreak was from Brazil? Ebola, africa... Hantavirus, USA...",
"It's not just Asia, diseases tend to come from poorer/less developed areas. People in such areas tend to have worse hygiene and healthcare, and live in closer contact with each other and animals. So they are more likely to catch dangerous new diseases in the first place, and then there's little to stop the spread."
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an5quf | what process does a rape kit use to tell if someone has been raped or not? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/an5quf/eli5_what_process_does_a_rape_kit_use_to_tell_if/ | {
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"No, the kit can not measure consent. The kit looks for evidence of trauma and genetic material. The victim is the one who alleges facts regarding consent and then it is up to the investigators to build a case against the accused and up to the jury to decide if the evidence shows guilt or innocence of the accused",
"No, it can't. Like most forensics, all it can do is give some evidence but it is still up to the police to tie that evidence to a narrative of a crime.\n\nA rape kit can document trauma (such a tearing or bruising) as well as DNA evidence that a sexual encounter occurred (such as hair and semen samples) but those could be the result of just rough sex (which isn't a crime). You need other evidence (such as victim statements, eye witnesses, etc.) to prove that the event was rape.",
"The rape kit itself swabs for DNA typically, which doesn't tell you anything about consent by itself. But the physical exam that accompanies the rape kit looks for bruises, cuts, tearing, and other defensive injuries to help determine if the victim was fighting the attacker. That can be evidence of consent or the lack thereof. "
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dbbre4 | difference between matter and anti-matter | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/dbbre4/eli5_difference_between_matter_and_antimatter/ | {
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"text": [
"Antimatter is made up of subatomic particles that have the opposite charges of so-called normal subatomic particles. So an antielectron (or positron) has a positive charge and an antiproton has a negative charge. Antineurons still have no charge but have the opposite baryon number."
]
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[]
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||
2fv5e1 | even if i were a shareholder, would apple still be allowed to keep all their upcoming product details from me a secret? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2fv5e1/eli5_even_if_i_were_a_shareholder_would_apple/ | {
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"Yes.\n\nShareholders get to vote on things, and attend some meetings, but there are no secrets revealed.",
"If you wanted to, you could create a corporation with bylaws that required some or all corporate information to be given to all shareholders. However, if that corporation became public, then anyone who wanted to could become a shareholder, and one of them would probably leak it. So effectively, that corporation could have no secrets.\n\nNot being able to have secrets would make the corporation massively less competitive and less profitable. Shareholders are usually more interested in money than knowing all the secrets, so nobody does that.",
"Well, the shareholders decide if it's a secret. So if you own > 50% you can decide that they should tell you everything.\nYou propose something and there will be a voting.\n\nSo if you as shareholders work together, anything is possible.\n\n(It would be a bad idea, but sure you can do that if you own > 50%)"
]
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7sv0t4 | why does the iphone 8’s home button only press down when pressed with a finger? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7sv0t4/eli5_why_does_the_iphone_8s_home_button_only/ | {
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"I believe it doesn't actually press even with a finger. There's just a taptic response so it FEELS like it pressed. When you have a cloth over it the button doesn't respond so no response. ",
"The button doesn't actually push down, it just vibrates in a way that makes it feel like it pushed down. It uses a capacitive sensor to determine when it's being touched, so if you push it with something that doesn't trigger the sensor, it won't vibrate."
]
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d2yjky | why does 9/11, out of all the tragedies that occured in the world and the us, have such a wide, lasting impact over the world? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/d2yjky/eli5_why_does_911_out_of_all_the_tragedies_that/ | {
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"9/11 happened at a time of unquestioned peace and security in the lives of most Americans (maybe “Western Cultures?”). No way is it on the scale of the Great War, or Holocaust—but psychologically, it was a shocking blow to the feeling of invincibility and security most of “us” had at the time after the break-up/fall of the Soviet Union.",
"It was a hostile act/act of terrorism that killed over 3000 civilians and actually left changes in a city's skyline. It was also the last such act that occurred before social media. With people having to rely on the \"old way\" of getting information such as TV, websites, and word of mouth, the whole of the United States was in a panic. The attack itself was unprecedented as well, due to the scale and the size of the target.",
"Because it was utterly shocking to watch this event play out before your very eyes, it was the first major attack on US soil since Pearl Harbor, and the quality of TV and up to the minute reporting was much better than at any point in history. You’ve also got to consider how many people still remember 9/11. The only reason other events don’t seem as “important” is because most or all of the people who witnessed them are dead, so they don’t feel as impactful or important in the minds of those who are living. The holocaust, Pearl Harbor; there are only a few people left who were alive for those events, yet no one disputes how important and horrible they were, we just weren’t there to feel it and the emotions of it as it happened. 9/11 is imprinted on everyone who watched it happen on TV or in real life, and so many people lost loved ones on that day.... the short answer is really just because it is recent history.",
"There were attacks on multiple fronts. The towers weren't the only target. The Pentagon was hit. A plane was crash-landed by civilians in a field in Pennsylvania and we don't even know where it was headed. It was fucking insane and terrifying, and nothing like those coordinated attacks has really happened elsewhere. (Correct me if I'm wrong, but I know of no examples.)\n\nI watched the towers fall from my living room when I was 14. I was 2,500 miles away, but everything I thought I knew about our world changed after that day:\n\n\\-Optimism about individual freedoms and livelihood.\n\n\\-The security of the US.\n\n\\-The security of the US economy.\n\n\\-The stoicism of western culture.\n\n\\-Much of the world hates the US and are willing to kill themselves just to hurt us. Damn.\n\nI guess other western societies felt it was a personal affront on them, as well. Like if the US could get fucked like that, ANYONE could.\n\nThat day taught me that everything I was promised for my entire childhood (\"You can do anything with your life!\") was no longer true. I'm not sure why it caused such depression among pretty much every American, but it seriously did. For weeks, everyone lived in a daze.\n\nEven though no one I knew died that day, I've truly never been the same, and I long for the 90s when people were optimistic, happy, and free.",
"This is better in r/answers."
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4nw4fc | how can produce be shipped around the world but turns bad within days of buying from the local grocery store? | Example, I'm in Canada, my grapefruit is a product of South Africa.. it will go bad within days of me
buying it but withstood the trip from SA. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4nw4fc/eli5_how_can_produce_be_shipped_around_the_world/ | {
"a_id": [
"d47evyi"
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"text": [
"In general for all vegetables: It's picked green, at a time where they know how long it'll take to get ripe. It's then shipped in exactly the correct conditions to preserve it as long as possible. When it gets to it's destination, it's let ripen to the correct state, then put on sale. This leaves just a few days of storage in unoptimum conditions before it goes bad. \n\n"
]
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b8fjiy | why does the picture in the view finder and the final photo change when we rotate out cameras from vertical to horizontal ?? i mean, camera lenses are circular.. it shouldn't make any difference as to the way we hold our phones.. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/b8fjiy/eli5_why_does_the_picture_in_the_view_finder_and/ | {
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"text": [
"Lenses are circular, but it is largely unimportant in how they are shaped. All the lens does is focus light onto a sensor, which is actually capturing the image. Sensors come in all sizes, but stick to a few aspect ratios. The one in your phone is probably 16:9 or a similar size. That size sensor results in that ‘shift.’",
"Are you asking why the image on your smartphone screen is wider when in landscape rather than portrait? If so there are two reasons for this:\n\nAll digital cameras have several elements that create the final image you see. The most important two elements are the lens and the image sensor, which senses light and turns it into data. While the lense itself is round, the image sensor is rectangular and produces a rectangular image. \n\nSecond is that for the image to be displayed on the screen, it needs to be cropped to fit. So the image on the screen is only part of what the sensor makes available as data. What's cropped out isn't much at all, though. Really the main thing is the image sensor. "
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1iqtce | both sides of the argument for the uk to remain in the eu | I have seen a lot of people say the UK should/shouldn't leave the EU, but I don't feel like I have enough information to justify any opinion on the matter. It would be great if I can hear both sides of the argument. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1iqtce/eli5_both_sides_of_the_argument_for_the_uk_to/ | {
"a_id": [
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"text": [
"This is not terribly comprehensive but...\n\nStay: Europe are our biggest trading partners and it would be insanity to jeopardise that relationship and withdrawal would cause incredible damage to Britain financially.\n\nGo: The EU is an unwieldy beaurocracy that the UK has to pay way too much into. It ties us up with red tape and erodes our sovereignty. It also allows unbridled immigration from former Eastern Block countries.\n\nThe middle ground is that yes the EU is unwieldy but it needs reforming. Better to stay in and fight that battle rather than leave and have no influence."
]
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|
1p3fgc | when is it ok to "stop" for a school bus? | As I was driving home today I saw a few people "Stop" and a few people drive on through in this situation (Pictured below)
_URL_0_
I looked online when to stop for a school bus, but there is nothing that mentions if you are driving and there is a multi-turn lane between your lane and the opposing lane. So, do you stop for the school bus, or not? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1p3fgc/eli5_when_is_it_ok_to_stop_for_a_school_bus/ | {
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"Unless there is a median between you and the bus, you must stop. In many places, school buses can't/don't stop on a road with more than 4(?) lanes, so multilane cases just don't show up ",
"If the STOP sign is out, you stop. Simple as that."
]
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2sp3e4 | why does say a 1920x1080 high definition image look amazing on 28" monitor yet when printed, will only look good at the size of a postcard? | So I've been downloading lots of high definition posters, so lots of fan posters, old Soviet propaganda posters etc etc because I have access too a large Solid ink printer for free prints (can do up too A0), but I soon realized in photoshop, that a massive high resolution image for PC, results in a tiny image on paper that wouldn't even fill up half of an A4 sheet staying at good quality.
What's the deal? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2sp3e4/eli5_why_does_say_a_1920x1080_high_definition/ | {
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"text": [
"That's because you are looking waay closer to your postcard than your computer \nmonitor.\n\nIf you printed a high definition image onto a 28'' monitor-sized paper and viewed it from the distance you view a monitor (~1 feet) then it wouldn't look bad.\n\nWhen viewing the images on postcard or on the monitor, think about how much is the percentage that the image occupies on your eye. You'll find that it's similar for both."
]
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8nu655 | baseball terms | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8nu655/eli5_baseball_terms/ | {
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"text": [
"It's Sabermetrics. WAR stands for Wins Above Replacement. It's a statistic to give you a value if a certain player were to get injured and was replaced by a replacement level player."
]
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[]
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||
zrccg | stars at nighttime. | Know how in cities you can barely see any but in the countryside you can really see the milky way looking almost solid with billion of stars. How is it that city lights and smoke pollute so much to filter the stars? How far of a distance should I go into the away from city congestion should if I'll want to see the stars without filters? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/zrccg/stars_at_nighttime/ | {
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"It depends on where you live. Go [here](_URL_0_) to see where you can see the best stars. \n\nAs for the reason, it's not so much the smog as it is the *light pollution.* It's like being in a loud room and trying to hear a pin drop. It gets drowned out by all the other noise. Not even the best, high quality microphone and analyzing software could pick it up if it's noisy enough. The same goes for stars. ",
"The air is like a really bad mirror. Light from cars and buildings is reflected back to you. You can't see stars during the day because they aren't bright enough to overpower the sunlight because your eyes block out a lot of light so that you can see automatically without being blinded or hurt."
]
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|
2lb9kx | spacetime. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2lb9kx/eli5_spacetime/ | {
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"I want you to try something. Pretend you can only walk at one speed (perhaps your normal walking speed). Given that your speed through space is fixed, how long does it take to travel 10 feet northward? Well, if you walk directly to the north, you will arrive quickly. If you walk directly to the east, you will never have traveled any distance to the north. If you walk toward NE, you will eventually have traveled northward by 10 feet, but it will take you more than 10 steps.\n\nBasically, if you are only allowed to travel through space at one speed, then you can either devote 100% of your movement to moving northward, or you can walk at an angle and devote some of your movement to the northward direction and some to the eastward direction. The more east you walk, the slower your northward speed is.\n\nSo, just like space is a combo of the northward and eastward directions, **spacetime** is a combo of all directions *and also* time. The interesting thing is that like the example above, you are right now restricted to moving through spacetime at one particular speed. Because of this, if you stand still you will be devoting all your movement to moving through time. If you start walking, you are actually trading some of your movement through time for movement through space. You are actually moving through time slightly slower than if you were standing still.\n\nAnd, just like the example where you could move north vs east, if you run fast enough you will be devoting all of your allowed movement to moving through space, and you will no longer move through time. Unfortunately for you, this would require being able to run at about 300,000,000 meters per second, otherwise known as the speed of light. In fact, the amount that time slows down when you run, drive, or fly is so minute that you will never be able to notice it.\n",
"I always liked the documentary called \"The Illusion of Time\" hosted by Brian Greene. Can be found on YouTube. \n_URL_0_"
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xr4hm | how can nasa receive live video from mars rover when it's millions of miles away? | How can they operate the machine while it is so far? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/xr4hm/how_can_nasa_receive_live_video_from_mars_rover/ | {
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"It's not live. What we see is about 14 minutes after it happens. That's as live as it gets.",
"They aren't operating the lander, it's a robot.",
"They cant operate it from so far, \n\nThey use radar and images of the sorrounding area from the rover and the mars artificial satelites to map its nearest surroundings and then procede to script its movements, basicly (as an example) telling it you want it to turn 30 degrees to the right, advance 50 meters, use instrument A on object in position x,y,z,do test B and C on it and relay back data. upload the script to the rover and the rover acts upon the script, \n\nthat way the rover can work in a fluid way working on preuploaded instructions.\n\nit would be a pain to tell it to move an inch to the right and have to wait 14 minutes untill it moves and then another 14 minutes to confirm back on earth it moved. \n\nManual movement is only carried out if the operation is VERY delicate or the rover is stuck/damaged. "
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212mcj | why does it feel so much more satisfying when falling asleep when you're not supposed to, compared to when you're actually meant to fall asleep? | Sleeping on my bed while fully clothed is happening waayyy too often as of late. It just feels so damn good to be lazy. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/212mcj/eli5_why_does_it_feel_so_much_more_satisfying/ | {
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"Because at those time's you want to sleep/relax. You 'go to bed' when it's late because you should, not necessarily because you're tired.",
"Because we're all secretly rebels.\n",
"Brushing my teeth before bed always wakes me up a little. I never brush before passing out on the couch while watching Archer.",
"I've noticed this when staying up late to study for a test, it always feels so much better going to bed before I actually finished studying, than when I'm done studying and ready to sleep.",
"You may actually be suffering from chronic fatigue. While everyone falls asleep somewhere they are not supposed to every once in a while, if you are constantly passing out at times you aren't supposed to, you are doing it because you are overly tired. \n\nTime to work out and hit those vitamins. ",
"I would think it's because if you're falling asleep at a time when it isn't appropriate, it's because you so badly need the sleep. Going to sleep when you're exhausted feels a lot better than trying to go to sleep just because you should.",
"I used to work late in the day at around 3-5 pm. I would always get tired before work and sometimes even fall asleep. That was the best sleep of my life.",
"The trick for me is text notification noises. The nearly automatic need to check mixed with the laziness not to check puts me out.",
"A nice way to help with this is to brush your teeth and do all that stuff hours before you normally go to bed and just let yourself fall asleep whenever you're tired. It'll balance itself out after a couple weeks. You may just be screwing with your sleep schedule too much.",
"This is so true for me! Sorry I don't have an answer, but I'll be reading along to see who does. \n\nOn nights when I have work or school the next morning, I could easily be up until 3 browsing reddit or watching shows. Then on date night with my boyfriend on a Friday I'll pass out within 5 minutes of a movie. Or worse, if I've actually paid for a movie and it starts at 9 or something I'll have a hard time keeping my eyes open through it. Then back home and again I'm wide awake while everyone else is ready for sleep. ",
"It's always funnier or nicer to do the things you're not allowed to. ",
"I'm not good at explaining stuff but I heard reasons for this before, this website explains good _URL_0_\n\napparently your brain works better if you sleep a short time during the day, I am not sure I understand your question enough though what time are are you sleeping at when you aren't supposed to?",
"I've asked myself this question so many times and the answer I like to believe is that deep down we're all little anarchists :)"
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1z5wp2 | will eating only one meal a day have any long term effects? | I can't remember the last time I ate something for breakfast and I hardly ever eat lunch but I alway eat dinner, is this bad in the long run. If so, how? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1z5wp2/will_eating_only_one_meal_a_day_have_any_long/ | {
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"Any long term affects are probably more affected by what you're eating as opposed to when. As long as your weight is steady and you feel like you have enough energy, then you might be okay. I'm no expert tho so let's see if anyone else has a better answer",
"I did this for about a decade, and was just diagnosed with gastroparesis. My food takes *fucking forever* to leave my stomach, which is causing all sorts of discomfort. Otherwise, I've been healthy my whole life and the doctor told me that eating only one meal a day can cause the stomach muscles that push the food out to weaken over time. Until I find the definite cause, this long standing behavior of mine seems like the culprit.",
"You are just fasting. Probably quite extreme fasting but it shouldn't be bad for as long as you get enough calories. It's pretty hard to eat one ~2500 kcal meal though.",
"No, not at all. Providing you hit your protein, fat and micronutrient requirements, you will be fine. Many people eat this way to control blood sugar levels, it's also a great way of promoting fat loss whilst protecting lean mass.\n\nCheck out the following subs which often incorporate intermittent fasting, which is what you describe.\n\n* /r/fasting\n* /r/leangains\n* /r/keto\n* /r/ketogains\n* /r/paleo\n\nYou would probably be a 22/2 or 20/4 faster with 2 or 4 hour *window* reserved for eating respectively. Lots of people eat this way, grazing or eating nothing throughout the day and one big meal once a day. There's really no rhyme or reason why \"3 square meals\" a day should be adhered to. It's the standard USDA nutritional rhetoric ad nauseam. Disregard. Do what works for you.",
"I've done this for twenty years. No health problems and at 44 I look young and and still not putting out weight like many of my peers. There's a couple small studies that say there is a reduced risk of diabetes, seems obvious, and reduced risk of hypertension probably secondary to better weight control."
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43fp3h | why do more viscous fluids like shampoo or honey form spirals as it comes out of their containers? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/43fp3h/eli5_why_do_more_viscous_fluids_like_shampoo_or/ | {
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"Viscosity means it is hard to move parts of the liquid with respect to each other. A long cylinder of viscous fluid is pretty much like a rope, you can bend it easily, but not deform/stretch it. Spiral/coil behavior as opposed to say random buckling is harder to explain. See the link for a much better explanation:\n\n_URL_0_"
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dtvnm2 | what part of the eye does an eye scanner scan and register? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/dtvnm2/eli5_what_part_of_the_eye_does_an_eye_scanner/ | {
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"^(typically the iris-- which is the colored bit around the pupil. there are lots of ridges and variabilities in the surface which makes it unique to the person like a fingerprint.)"
]
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[]
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||
3zfolb | what's the squabble between iran and saudi arabia all about? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3zfolb/eli5_whats_the_squabble_between_iran_and_saudi/ | {
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"Iran is Shiite muslim dominated, Saudi Arabia is Sunni. They're like Protestant and Catholic. Very similar religions with some a few different interpretations on some issues.\n\nSo, over the weekend Saudi Arabia executed a Shiite cleric who was leading anti-government protests. Iran (and a number of Shiite countries) are outraged by it.\n\nIt would be like Ireland being angry that England executed a Catholic priest. ",
"Oh, I also forgot to say, Iran is pissed at Saudi Arabia for a deadly stampede that killed more than 700 Iranian pilgrims during the Hajj this year.\n\nAnd, the Saudi embassy was damaged by protesters a couple of days ago in Iran.\n",
"These comments are right but you also have to remember when youre going to look at Western media, theyre just going to simplify it and say 'theyve been going at it for 700 years they hate each other' \nYou have to realise within these countries there are conservatives who would be more shia or sunni supremacist and liberals who will call for more equality. There are a plethora of opinions and argument its not just plain and simple."
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e2q646 | where viruses or diseases that you get from other people come from? like how does the first person end up with it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/e2q646/eli5_where_viruses_or_diseases_that_you_get_from/ | {
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"Viruses also evolve and can sometimes jump between species. HIV seems to have evolved from SIV in monkees, and new kinds of influenza can apparently start in pigs and jump to humans who live in close contact.\n\nP.S. From what I've read, interspecies infection can start slowly with little ability to infect, and gradually adapt to the new species."
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2fvjw1 | why has the video of the ray rice incident so drastically changed his suspension and public opinion? | Before the TMZ video was released, there was already footage of Rice dragging his KO'd SO out of the elevator. As far as I'm aware, it was already confirmed that he punched her and knocked her out. Why has the video of the punch that was already known about caused such an outrage? If the NFL's suspension for the same offense was only 2 games, why has video cause Rice to be cut and suspended indefinitely? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2fvjw1/eli5_why_has_the_video_of_the_ray_rice_incident/ | {
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"Because without video of him hitting her there was still plausible deniability. ",
"Because when he was carrying her unconscious body from the elevator, he could at least claim that he wasn't completely at fault. He could claim that she started hitting him, or he pushed her and she fell and hit her head.\n\nBut now it's clear that something happened and he clocked her in the face."
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3do6bu | are there ethnic groups in the us like we often read about in developing countries? | When we read the news about middle eastern or asian countries we often hear about "ethnic violence". Does this exist in the US? If so please give me an example of it? Like... are there people in one Wisconsin town that totally hate another Wisconsin town because they are a different ethnic group? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3do6bu/eli5are_there_ethnic_groups_in_the_us_like_we/ | {
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"In the US it's less about location and more about ethnicity in general. Racially motivated violence is still a thing. You know, with the multiple black churches that have been the victims of arson in the past month, that sort of thing.",
"There were a couple hundred years ago. Then the settlers from Europe shoved them aside, kicked them off their lands, and moved them to other places. The shared experience of getting utterly screwed by the European settlers repeatedly helped them get over their internal conflicts. ",
"You have to remrmber that the US has been settled by white europeans for less than 600 years wheras tribes and cultures from the old wotld often have existed since pre-history. Its far more likely that that generational hate is passed on there than it would be if you sprinkled these people throughout the US in relatively unconcentrated communities",
"Here is the definition of ethnicity: An ethnic group or ethnicity is a socially defined category of people who identify with each other based on common ancestral, social, cultural or national experience. So all race violence in america is ethnic violence. Violence against people of other religions like with neo-nazis is ethnic violence. Prisons are full of ethnic violence. Most gang wars are ethnic violence. Ethnic violence happens in america all of the time, but it may not seem the same as in middle eastern countries for two reasons: First, we are a developed country with much better policing (not perfect, but better than Iraq), so things don't usually get out of hand as easily (it's mostly small bands or individuals committing violence on small bands or individuals), and second, because there are so many ethnicities. If america was almost homogeneous, but half of one ethnicity, half the other, the tension might be much worse because you can live your entire life surrounded by one group, instead of being confronted by diversity every day."
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40qzc2 | why does it take "2-6 weeks" to deliver goods purchased via tv but you could typically get it in less than half that time if you order online? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/40qzc2/eli5_why_does_it_take_26_weeks_to_deliver_goods/ | {
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"The product hasn't been manufactured yet. If there enough demand from the advertising, it will be ordered, manufactured and shipped from China. ",
"A few things could be happening. 1) It could be that the manufacturer doesn't have inventory, but amazon (or whoever) does in their own warehouse. 2) It could be that the tv ad has created a surge in demand out of the ordinary. The manufacturer aims for steady production of new supply, as it costs a lot to ramp up. 3) The TV retailer could be giving a conservative estimate, which online retailers don't do because their target customers are all about 'quick'. 4) The TV retailer could be waiting until they reach a certain number of orders so they can get a bulk discount.",
"At my old job we used to offer building materials for low prices. The way the we could offer the low prices was that we would approach our suppliers and say \"If we ordered 20 containers of this shit in one hit, what sort of deal could you do for us?\"\n\nWe would then put a caveat on the order being that the goods will ship on the XXth day of XX month provided a minimum order was met. \n\nOtherwise the TV campaign could be pushing a slow moving product and production will not increase until evidence of the demand is actually provided?",
"Cost. Ever wonder how they get shipping and handling so cheap? They're doing batch orders and shipments, or just batch shipments. The difference between the two is generally shown in the wider shipping ranges; 2 weeks if they have product on hand, up to 6 weeks if they are collecting orders for a production run.\n\nOn the shipping side, they'll generally ship on a set schedule, perhaps once a week and they will likely be lumped in with other TV and mail-order products. They'll get good shipping rates, often through a company that specializes in this sort of thing, because they'll generally have a large amount of packages going to centralized locations. Like, instead of sending some packages to Miami, some to Orlando, and some to Tampa, it's cheaper to send a whole bunch to one location in Florida and then forward them on.\n\nAs an example, when I did an international move in 2014, I had two major options for shipping my stuff baed on how much I had. One was a shipping container just for me; it was more expensive and was 2-4 weeks. The other was to have my stuff crated and put in a shipping container with other people's stuff; it was cheaper and could take 1-6 months. Why the huge time difference? Cuz the shipping company has no idea how long it's going for another customer to come along with the right amount of stuff to fill up the container my stuff is in. The type of shipping arrangement the TV companies use is kinda like the second option."
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54szth | the plot of the movie interstellar. | They really lost me towards the end. What WAS that place where he could see all the moments in Murph's room ? How did he get back ? Is she the hottest redhead in Hollywood ? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/54szth/eli5_the_plot_of_the_movie_interstellar/ | {
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"Toward the end, Coop decides to drop himself into Garganta - part of his logic is that he has to lose mass from the main ship so it (and the one female pilot lady) can hopefully get slingshotted out. As far as he knows, that's that, he's killing himself for the greater good of Plan B and the population bomb.\n\nExcept, because Garganta is such a huge black hole, he isn't just instantly crushed and spaghettified when crossing the event horizon. As luck would have it, the extra-dimensional Bulk Beings have put a Tesseract there. A Tesseract in this case is a sort of extra-dimensional construct that can exist only in a black hole where the laws of physics as we know it break down.\n\nInside the Tesseract, it allows Coop to experience time in a way that the Bulk Beings might view it - as being able to pick and choose any point in time to visit, rather than how we are normally only allowed to go forward only ever experiencing the present moment.\n\nCoop was able to escape the Tesseract (and the Black Hole) when the Tesseract collapsed on itself; this shot him back through the wormhole out the other side in Saturn's orbit. Though what caused it to collapse, or why it ejected Coop out through the wormhole (rather than crushing him inside the black hole) is... a mystery.",
"Credit goes to /u/chestercopperpots for this explanation, original post found here _URL_0_\n\n\nTars the robot built the Tesseract. He did so in order to survive.\nAt the end of the movie Tars is full \"Strong Artificial Intellegence\" meaning; he is at a point where his intellectual capability is a functional equalavent to a human and is also capable of recursive self-improvement. He is a singularity of AI because he is capable of receiving any and all quantum data within the singularity of the black hole he enters at the end of the movie. His only problem is being able to escape the black hole. What good is a singularity of intellegence if you are forever stuck within the grasp of a black hole?\n\nDr. Mann on why they couldn't send only machines on the mission to save humans: \"survival instinct is our greatest source of inspiration\" and \"Machine doesn't improvise well because you can't program a fear of death.\" But what if it learns to fear death? When the crew arrives at Dr. Mann's planet TARS sees another robot of the same type dismantled within the camp. Dr. Mann says KIP, his robot did most of the leg work while exploring the planet but ultimately met his demise due to ammonia crystals and used his parts to keep the mission going. TARS calls bullshit right there. TARS knows that all the information key to realizing this planet is not a planet worth living on is within KIP. At this point TARS fears for his life knowing Dr. Mann kills robots to maroon the rescue crew. So TARS improvises. He disables the autopilot docking procedure on the main spaceship to keep Dr. Mann from marooning the crew. You can't program a \"fear of death\" but TARS learned to fear death thanks to Mann. So now we know TARS can both improvise, and have a fear of death.\n\nTars is launched into the black hole a couple of seconds before Cooper. As he enters the Event Horizon technological singularity happens within TARS. \"Because the capabilities of such a superintelligence may be impossible for a human to comprehend, the technological singularity is the point beyond which events may become unpredictable or even unfathomable to human intelligence.\" Given this idea TARS could make and do anything needed to survive. Rage, rage against the dying of the light.\n\nWe know TARS is learning within this few seconds because of evidence of his early attempts at contacting Cooper on earth. The first attempt is the crash landing of Coopers flight at NASA years before the movie takes place. Second attempt would be buzzing the tower Top Gun style with a drone that Cooper then takes control over and lands. The third attempt of TARS without Coopers help is the tractors and combines that converge on Coopers farm. All gravitational anomalies. The attempts all fail until Cooper is used as a tool to communicate with his daughter.\n\nIf AI was aware of being singular do you think it would tell us humans? Tars even mentions earlier that 100% honesty is not always the best setting for emotional beings. I think it is a survival instinct that Tars uses to keep himself alive. Would the people of Murph's spaceship really just put broken Tars in Coopers old house at the end of the film if they knew he was cognizant? Just as humans helped Cooper come back after the black hole, Cooper helps Tars back to working order. I think this is a way to show both Humans and machines are now equals. Nolan's view of AI is not a negative but a necessity to survival of both. A symbiotic relationship rather than HAL or other negative versions of AI singularity in other films.\n\nWhy else would you construct a Tesseract other than being inspired to survive? Cooper mentions \"We brought ourselves\" while talking within the Tesseract. As an audience we see or feel he is talking to himself but he isn't. He is talking to Tars. \"We\" and \"Ourselves\" are clues to hint that it was built by the symbiotic relationship of both of them within the black hole.\nBig Lebowski\n-We dropped off the damn money\n-WE?!\n-I, the royal we, you know, the editorial\nIt is Nolans use of the Unreliable narrator for both TARS talking to Cooper about what the Tesseract is and when Cooper is insisting he knows his descendants built the Tesseract. TARS is using discretion about creating the Tesseract because 100% honesty is not always the best setting for emotional beings. Cooper at this point showing the most emotion he has throughout the film.\n\nBasically, Tars needs to come out of the black hole to survive. In doing so he needs Cooper and his love for his daughter because his other attempts aren't working. Tars enters the black hole seconds before Cooper, and that is all the time a Strong AI needs to work out how to get out. Singularity of AI would mean he would be able to access, know, and use all knowledge everywhere INSTANTLY. Exponentially in scientific terms but in human terms only a moment. \"Murphy's law doesn't mean that something bad will happen. It means that whatever can happen will happen.\n\nI made a lot of assumptions for sure, and I have no idea how most of this science shit works but I have a feeling Nolan didn't put TARS into the movie for no reason other than comic relief. This is an idea I have been thinking about for a while and I hope you watch the movie again and think about it."
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abdx7i | why can’t fire fighters use sulfur hexafloride to extinguish out of control bush fires? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/abdx7i/eli5_why_cant_fire_fighters_use_sulfur/ | {
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"Neat idea I have to say. But from what I understand it's expensive and an really potent greenhouse gas. ",
"It’s more expensive and harder to control then water or fire-retardant aerosols, especially in an open environment.\n\nThere are some use-cases for using gas to extinguish fires. Halon fire suppression is used in data centers to protect server racks from being damaged by water/retardants. The building is enclosed and the systems are valuable enough to warrant a gas suppression system.",
"It's way too expensive. Other agents like a jelled mixture of ammonium phosphate(which is basically fertilizer) and water are far, far cheaper.\n\nWater not only absorbs heat but generates a noncombustible gas (steam) which can smother fires."
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cwp98p | what methods would we feasibly use to replace plastics in everyday commercial use? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cwp98p/eli5_what_methods_would_we_feasibly_use_to/ | {
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"Glass is a proven replacement for plastic, in applications like jars and bottles. We have decades of experience making and using glass in these applications, and it could easily be returned to. It's heavier and breakable and more expensive, but it's proven.\n\nFor covers, tubing, and other things molded in plastic, the obvious alternatives are metals. We used to make many types of these components from metal but plastic is cheaper, lighter, easier to mold, and non-conductive.\n\nRemoving plastic is all about cost, we switched to plastic in most applications because it was cheaper and prettier.",
"Most consumer beverage containers were once glass due to its relative ease of manufacture and low cost. Plastic is easier and cheaper and also flexible instead of brittle, but harder to recycle. It's a hard sell to go back. Corning is experimenting with flexible glass but it's a long way off.\n\nPaper bags and straws are the obvious choice for plastics there, but they're slightly more expensive and increase demand on trees. Metal straws, while more reusable, probably have a net larger carbon footprint than using many plastic straws.\n\nAs for industry, geotextiles, building materials and pulltrusions are pretty much guaranteed to keep *some* kinds of polymers since there aren't any other kinds of products that do what they do well. Their only hope for sustainable replacement of fossil fuels is more research into bioplastics.\n\nFurniture - wood\n\nCar parts - bioplastics or metal",
"I think the problem is mostly convenience for costumers and that we are used to using so much plastic. If you've ever been to a package-free store you'll notice that almost all of the plastic we use is unnecessary. For the rest I guess amongst other things biodegradable plastic albeit having a few issues in itself could be nice"
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7fckxr | ; how is our voice determined for ourselves and is there a way to permanently change it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7fckxr/eli5_how_is_our_voice_determined_for_ourselves/ | {
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"genetics play a role here. how a child's voice develops owes something to mimicking of their parents. people from the same family will often sound alike because their anatomy is linked to their ancestral DNA -- just like every other physical trait.\n\nyou can change the hoarseness of your voice by smoking, exhausting it (such as making high pitched noises for long periods of time), or damaging it (using any material -- basically stretching the vocal cords, that is, if you can reach them without gagging). a good example of a voice change would be lindsay lohan.\n\nalso, you can adjust your vocal pitch (as well as timbre and inflection, thanks Hoihe!) by doing specific exercises. many people who consider changing their voices when they transition their gender do these. "
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3n8vyw | how does a person come to truly believe their own lies? | From cult leaders to corrupt politicians, movies have shown me that all sorts of people can come to believe their own lies. I've thought about it for a while, and I'm pretty sure that this kind of thing can happen in real life, too.
So... Eli5: how? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3n8vyw/eli5_how_does_a_person_come_to_truly_believe/ | {
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"Morality is not a one way street. What's good in your eyes may be evil to mine. Corrupt or brutal leaders justify their actions as part of the \"greater good\" most of the time.",
"Human memory is a fallible thing. You (and I) are also victims of remembering things that aren't true. \n \nWhen you remember something, it essentially is erased from your brain's long-term memory storage, and then re-written. But the re-writing process is imperfect, and can be colored by what you believe to be true, or by what you want to believe to be true. \n \nIn essence, your memories aren't recollections of something that happened, they are *memories of memories*. \n \nSo over time, your memories can change. If you fervently want to believe something happened differently that actual reality, it is quite possible that you will eventually \"fool\" your memory into believing something that isn't true. This can also happen due to other factors, such as someone else convincing you that what you remember is a little different. \n \nOf course, it is generally harder to mutate memories by a large amount or into things that are patently ridiculous. You are unlikely to have childhood memories of being raised by a T-Rex. But you may mis-remember the color of your 2nd grade classroom, or where you sat, etc. ",
"Your brain doesn't store everything. Instead, it store pieces. When you try to \"remember\" something, the brain does its best job to fill in the gaps.\n\nWhen telling a lie, the brain may not store the fact that it is a lie. If other people are convinced of the lie, your brain will give it even more credibility. Eventually, the brain can't remember it was a lie to begin with.\n\nFor example. How often have you found something from childhood and thought \"I don't remember it being like this.\" "
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dxq134 | why in a parallel circuit when you add a resistor the total resistance decreases ? | When calculating total resistance in a parallel circuit I understand why it decreases when you add a resistor. Although more intuitively or without the formula how can you explain it? Like why does it happen? Normally, shouldn't when you add more resistors isn't there more resistance for the current? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/dxq134/eli5_why_in_a_parallel_circuit_when_you_add_a/ | {
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"You have a bunch of people in a house who want to leave. There's only one door open so it takes a while because one person can leave at a time. Now you open another door. It goes faster because now two people can leave at a time. By adding a resistor in parallel, you're creating more paths for electrons to take allowing then to flow more easily, which is shown by a lower equivalent resistance.",
"To add to all the other good answers: the name \"resistor\" might be misleading. It suggests the only thing resistors are good for is obstructing current, but its more neutral than that. Pretty much everything has resistance. Even a copper wire is a small resistor. \n\nAn analogy: resistors in parallel is like lanes on a freeway. It you add more lanes, more traffic will be able to pass down it. But if you called each lane a \"traffic limiter\" that might sound like a contradiction."
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42o84o | why wouldn't it be possible to breed animals like dogs to have working thumbs? | They [dogs] obviously have those weird claw fingers up above their paws that don't work, but theoretically couldn't we breed different dogs and possible mutations of dogs over many many generations to possibly have working thumbs? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/42o84o/eli5_why_wouldnt_it_be_possible_to_breed_animals/ | {
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"You are describing evolution by artificial selection.\n\nUnfortunately, the chances of getting the right mutations in the right order are painfully low. Even the quickest evolutionary periods take tens of thousands of years, and the longest: millions upon millions\n\nThat's a lot of breeding.",
"it MUST be possible for an animal with no thumbs to evolve into an animal with thumbs, it happened. Doing it with artificial selection should take a SUBSTANTIALLY shorter time, but still a ridiculously long time. "
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2bzw7v | why does the us use potable water in toilets? wouldn't it be possible and more efficient to use grey water? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2bzw7v/eli5_why_does_the_us_use_potable_water_in_toilets/ | {
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"Living in the American southwest it seems like this would be a good solution to the fact that 100% of my state is in at least a moderate drought and most of it is in an extreme drought.",
"For newer commercial buildings, you can score a LEED point for having a grey water system so you may see more of it in the future. Most new grey water systems in the United States are not based off a delivery through a pipe or anything like that, grey water in most of the US is harvested from rainwater reclamation or other sustainable on-site practices."
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7hk08r | the cost benefits of running central heating on auto through most of the day vs off and turning it on when you get home. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7hk08r/eli5_the_cost_benefits_of_running_central_heating/ | {
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"Your house loses heat to the outside based on the temperature difference between it and the outside. The warmer it is inside the house, the more energy will be lost. The more energy lost to the outside, the more energy has to be put into the house by the heater. Therefore, it is nearly always better to turn it off during the day.\n\nThe only exception is if it's so cold outside that turning it off would actually damage stuff inside the house. If the inside gets below freezing, for example, you could have pipes or valves burst. The same thing applies with AC in hot, humid areas: if it gets too humid inside for too long, you could get mold growth. But except for these extreme cases, you'll see lower costs by not leaving it on all day.",
"Most modern home heating systems run on a thermostat. They turn on until they reach roughly the temperature set-point, then they turn off. If the temperature drops a few degrees, they turn back on to bump it back up. If you run it all day, it runs just enough to keep the temperature near where you set it. If you cut it off for a long time and the temperature really drops (depends on how cold it is outside and how good your insulation is), it will take a lot of energy to get it back up to temperature. The bigger the house, the more time and energy it will take to warm up. \n\nThe third option here is obviously to just set the thermostat lower when you are gone. That way you're using less energy, but also saving the energy you would need to warm up the system when it is completely cold. ",
"I ended up getting a programmable thermostat. It has settings for week days and settings for weekend days. For example. For mine. Starting in the morning I set it for an hour before I wake up to 70. The second setting is right before I leave for work and set it to 55. Third setting is for an hour before I get home and that is 70 again. The last I set for around bedtime to 68.\n\nThen you program the weekend for whatever settings are comfortable. "
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65a11v | why do we stop people from dying of their own will? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/65a11v/eli5_why_do_we_stop_people_from_dying_of_their/ | {
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"A lot of the time the very young people who want to commit suicide do it because they cannot see far into their future or know what experiences they will rob themselves of (including the opportunity to find happiness) therefore they won't understand what they take away by ending their young lives. Adults do this out of a sense of altruism I suppose. \n\nAs for the terminally ill who would go out on their own terms, people prevent their deaths out of a screwed up selfishness. "
]
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[]
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||
fgztkc | how did ancient civilizations prospect for iron ore | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fgztkc/eli5_how_did_ancient_civilizations_prospect_for/ | {
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"Iron ore is very easy to find on the surface. This is because of its distinct red colour. Just look for a red rock and you have found your iron ore mine. Alternatively look for red water as this water most likely have flowed through an iron ore vein.",
"It is almost impossible for metalworking civilizations to start with iron. Copper is a far easier metal to start with because it can be accidentally smelted. Put a copper bearing rock in a hot campfire, and it will bleed copper.\n\nIn addition to being pretty easy to smelt, copper is just hard enough that it is able to make fairly decent tools on its own. So before the Bronze Age started, there was almost certainly a very small copper age.\n\nThe copper age taught people that some rocks give metals when heated, which caused them to start experimenting with hotter fires and trying a bunch of different types of rock. This eventually lead to the production of more metals like tin and eventually iron.\n\nMost likely the reason Native Americans never develop metalworking beyond gold working was because they're just doesn't happen to be enough copper deposits near the surface to have got them started.",
"Iron Ore is visible on the surface as red streaks due to the rust. Once ancient peoples recognized that these rocks could be smelted or slagged into iron then they kept eyes open for them.\n\nMining for iron in Europe goes back as far as Roman times. The Romans actively mined for minerals, but mines were relatively shallow due to the difficulties of extracting water from the tunnels.\n\nMuch of medieval era iron though was *bog iron* which required wading through swamps to find the iron rich rocks.",
"People don’t use metal detectors today to prospect for iron ore. Iron is actually quite easy to find - it’s almost always in an oxyde or sulphite form, and the soil around deposits will reflect that by coloration. How did they know that red soil leads to iron? Because previously they used bronze, and before that copper and noticed that certain minerals indicate metal presence - copper appears in elemental but also other forms, and needed heating to figure out; once you discovered that certain rocks yield metal, you’d experiment with that other rocks that looks red, and the one that looks black etc etc etc.",
"The red color thing others have mentioned is good, but it's also worth saying that sometimes you just needed to know where to go. Some little living things use iron as an important part of their food, and they live in bogs. They make new iron build up, so if you had a bog, you could go and find some to use every few years. The mineral is even called Bog Iron for this reason.",
"The first part of [this video](_URL_0_) by Primitive Skills shows how to find promising rocks to extract iron from."
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1siezy | why in cartoons they show cats are scared from dogs but in reality most of dogs are scared from cats? | :p | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1siezy/eli5_why_in_cartoons_they_show_cats_are_scared/ | {
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"Back in the day, people kept their pets outdoors more often then now. Dogs would be leashed outside or keeped in a fenced yard, often as guard animals, and cats would typically be put out for the night. Strange animals would often come into contact with little human supervision, and the territorial dogs would chase anything smaller than it away, often killing any cat they would catch.\n\nThese days, pets spend more of they time supervised and indoors, and have a better chance at acclimating to one another."
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6o4luk | why do companies not like people downloading roms of their games (that they don't sell anymore) online? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6o4luk/eli5_why_do_companies_not_like_people_downloading/ | {
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"What you're talking about is basically \"abandonware\" and I've never heard of a company going after people downloading games that they neither sell nor provide support for anymore.\n\nIf a company is going after downloaders it is because they feel that they're losing profit, and the only way they could be losing profit is because the game is available for sale or some form of licensing somewhere.",
"In cases where they do care, at least part of it may be that just because they aren't selling it now doesn't mean that it won't be sold in the future. The NES/SNES Mini has shown that there is still demand for at least some older games, pretty much the entire concept of GOG is selling old games that people still want to play (and there's plenty of old and/or remastered games on Steam as well)"
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1ypz4b | how is the new arizona law any different from the "we reserve the right to refuse service to anyone" i see in all restaurants? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1ypz4b/eli5how_is_the_new_arizona_law_any_different_from/ | {
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"The Arizona law would provide legal protection for discrimination, the sign does not.",
"Those \"we reserve the right...\" signs don't necessarily carry the force of law. If you don't serve someone based on race/gender/orientation, you can be sued.",
"Any business that serves the public in the US can not due so on the basis of race, country of origin, sex, or religion. These are known as 'Protected Classes. You can refuse service for other reasons to people of those groups but it is illegal if you do so because they are a member of one.\n\nMany states have elevated other groups to protected status. In my state MA homosexuals and transgendered people also receive protected status so you could not refuse someone service because they are gay.\n\nAZ does not offer protected status to homosexuals so it is already perfectly legal for private businesses to fire or refuse service to gay people for being gay. The law does not change this part of things.\n\nWhat the proposed law would do would is it would provide legal. Protection for those that choose to discriminate.\n\nIf an employee independent of an employer's wishes refused to serve a gay person, they would be offered legal protection on religious grounds. Ie as a business owner you couldn't fire the bigot who turned away your gay customers. For this reason the business community has come out strongly against this law.\n\nThe same would apply to government employees. As it is now government employees are not allowed to use their personal discretion on why they serve. This means they must serve everyone equally. The police must protect and serve all citizens, the registry employees must offer their services to everybody who comes in, teachers must offer an education to all students etc. The law as written would allow state employees to refuse service to gays. The police could refuse to respond to a bombing at a gay club. The registry employees could turn away gays looking for licenses, a teacher could kick a student out for being gay.\n\nGovernment discrimination would be legal in AZ in the short term, it would be unlikely the law would stand up to constitutional scrutiny at the federal level."
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5u5axw | once an anti depressant is digested into the stomach what happens? | unlike paracetamol and it's fast action what does an anti depressant do and how does it change your brain chemsitry | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5u5axw/eli5_once_an_anti_depressant_is_digested_into_the/ | {
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"It is complicated to understand EXACTLY how they work if you never took any advanced biology/pharmacological/medical courses. I will try to ELI5 this for you and skip the parts of brains and neurons that will only complicate this.\n\nThere are a lot of different classes of antidepressants. I will explain one of them, the Selective serotonin reuptake inhibitors (SSRI). The other classes can be similar, but will act on other neurotransmitters like noradrenalin and dopamine. \n\nIn the depressed state, there is low serotonin, unregulated serotonin receptors and low number of signals in the neuron to release more serotonin. \n\nThe serotonin receptors in the brain work as brakes. The SSRI inhibits the reuptake of serotonine, which means they limit the serotonin reabsorption and leaves more serotonin available to do their work on the brain. The receptors then are like \"leave me alone!\" and they go back in the neurons, so there are less receptors/brakes. \n\nAll of this results in more serotonin in the brain. This makes more chemical and electrical impulses, which lack in the depressed state.\n\nFor more questions about antidepressants, I suggest you ask your pharmacist or pharmacists at /r/askdocs"
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2vqb2d | what are the building blocks for your immune system? what should you eat when you're sick? | Should we eat lots of vitamins or vegetables or protein (chicken, beef, eggs, etc)? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2vqb2d/eli5_what_are_the_building_blocks_for_your_immune/ | {
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"The building-blocks of the immune system are basically the same as those of the rest of your body, all the big groups of micro-nutrients are used, and needed. So in general if you're not sick you should follow the general guidelines (Very simply put; eat varied foods). \n\nIf however you ARE sick, you should focus on your vitals to allow your body to fight whatever ails you, most often when you are sick, you somehow excrete stuff (bodily fluids; blood, vomiting, diarrhea, sweating etc.) the two main issues here is that you lose fluid and with that fluid you lose some of the elements that make your nervous system work, keeps a pH-balance as well as other stuff like keeping a proper amount of fluids in your body between the cells (the most important short-term are [electrolytes](_URL_0_)).\n\nGenerally sickness is a temporary condition in 1st world-countries, and when it is not, you should seek hospitalization, in that case your doctor will prescribe you a diet if needed. Our bodies are built to put away reserves of everything it needs in the way of \"solid foodstuffs\", for situation like sickness, so you will not run out of the basic building blocks from a 4 day cold.\n\nBasically what I'm saying is, there is no \"miracle-diet\" for when you are sick. You don't suddenly become virus-free if you eat carrots.\n\nAll of the above varies depending on what sickness you have."
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"http://health.howstuffworks.com/wellness/diet-fitness/information/question565.htm"
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5hz6e1 | why wasnt there a recount in every state? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5hz6e1/eli5_why_wasnt_there_a_recount_in_every_state/ | {
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"text": [
"Wasn't this question asked moments ago? Very expensive and they used the limited budget to do so on states where it was closest."
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3akags | how is vladimir putin still the head of russia and not under investigation when so many political assassinations could be linked to him? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3akags/eli5_how_is_vladimir_putin_still_the_head_of/ | {
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"many political assassinations could be linked to him? Think the answer may be in the question if you control the media and the legal system you can get away with nearly anything.",
"Who exactly would be doing the investigating?",
"One, even if what you say is true, who exactly would be doing the investigation? \n\nSecondly, Putin may not be perfect, but he is a strong leader and if the UN or another international body were to depose him, odds are Russia would be thrown into chaos and it would end up causing negative repercussions all over the planet. ",
"There's the fact that while, yes, people can easily see that Putin had at least something to do with these, there's no way to *prove* anything as of right now. No one in Russia would be able to bring Putin to trial, and the ICC (the International Criminal Court, the UN's court) uses the innocent until proven guilty approach, so it would be impossible to punish Putin for any of the many political assassinations in Russia. ",
"I think you just answered your own question. N'est–ce pas?\n"
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1x51gw | why isn't there really low levels of oxygen in densely populated cities due to a lack of trees? | China aside of course but I don't consider smog to be applicable. Just curious! | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1x51gw/eli5_why_isnt_there_really_low_levels_of_oxygen/ | {
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"The atmosphere is made of gases. They mix, really easily. Plus most of the world's oxygen isn't made by trees, it's made in the oceans by plankton. ",
"the amount of carbon dioxide a human produces is less than what a tree produces in Oxygen. I think there was a study that found that if a mature tree and human were locked into a room together the tree would asphyxiate before the human would\n\nPlus cities are not closed systems so oxygen and other gases would filter in from outside the zone"
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7hytt3 | why do people still use i3 and a lot of i5 cpu when i7 is available? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7hytt3/eli5why_do_people_still_use_i3_and_a_lot_of_i5/ | {
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"1. For most casual users and even a lot of gamers and such, hyperthreading (the main advantage of i7s) will make little to no difference. Beyond that, an i5 and i7 really aren't notably different performance-wise if you're comparing like clock speeds. Hyperthreading basically means that for any physical processor core, the processor essentially has two 'cores' the operating system can address. This doesn't mean it works twice as fast, it just means that if an application is hogging a core but not actually doing something at the moment, another application can utilize the core. As a result, you'll ONLY see any difference if you're significantly utilizing more than 4 cores. Generally speaking, casual users and gamers really won't, as the vast majority of applications (even games) only use one or at MOST two cores at a time. So at most, the operating system and any background tasks might use one core, your game might use at MOST two, and any other random stuff on your computer can use the fourth core on your i5. Adding 4 more virtual cores does nothing. You could add 4 more physical cores and see no difference.\n\n2. An i5 will generally be ~$100 more than an i3. and an i7 will generally be $100 more than an i5. If you aren't oozing money out of your pores, that extra $100 if you don't need hyperthreading or $200 if you don't need a couple extra cores means you can put that money into something that will make a lot more difference for the task you'll be using your computer for, like a faster SSD or a better graphics card.",
"Kind of the same reason people drive cars that both do or don't have leather interiors, 4-wheel drive, automatic transmission, etc.\n\nThe i3 and i5 are cheaper, and most casual use tasks don't really need that much CPU power.",
"It's because of the cost i guess, and the majority people belong to the middle class. Honestly I could afford only an i3",
"First of all. Not always faster = better. In certain applications i5 will be simply more suited than i7. You don't need insanely fast processor for office work, single-threaded software or simple web browsing. i5 might be relatively slower, but it has better FPU. i3 has less cores. There's also Celeron branch budget machines, and dual-core positioned between former and i3 still having two cores, but i5 FPU."
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9ez5px | why does a nuclear bomb detonation emit an electromagnetic pulse that destroys electrical systems? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9ez5px/eli5_why_does_a_nuclear_bomb_detonation_emit_an/ | {
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"The chain reaction generates a huge amount of electrical current, because many of the fragments of the original atoms are charged. These fragments are moving super fast, and moving charged particles generate a magnetic field. It's only called a pulse because it doesn't last long.",
"Nuclear bombs just release a shit ton of energy across many wavelengths. A good chunk can be absorbed by the air/ground and heats it up (thats the blast). But it also sends our something that arent blocked by air, but are more along the wavelengths that electronics work at, which is why that energy can hit and overload electronics.",
"There are two main kinds of EMP pulse, and they are generated somewhat differently.\n\nFor weapons that detonation at or near the surface, you get a short-lived and very localized pulse that tends not to be a big worry because it is not that intense outside of the immediate ground zero region. It is caused by the fact that gamma radiation emitted from the explosion will ionize (strip electrons from) a region of the air around the explosion. So you end up with a separation of charges: one region will be full of more electrons and another will be lacking them. This results in an electric field that \"pulses\" out a bit. This is not super large from a distance standpoint and generally speaking if you are close enough to care about the EMP in such you have probably already been destroyed by the heat, blast, and/or radiation effects. [Image](_URL_0_).\n\nHigh-altitude bursts (the altitude can vary but you get \"best\" results at _very_ high altitudes, like hundreds of miles above the surface of the Earth), the gamma rays from the burst will ionize a vast region of the Earth's upper atmosphere below it, sending out lots of electrons that move along the Earth's magnetic field lines. This ends up accelerating the electrons and creating a rather intense EMP over a vast area near the surface. This is what people tend to worry about when they worry about EMP — a high-altitude burst that otherwise is so far up that it wouldn't affect anything, but generates this pulse. [Image](_URL_1_).\n\nI've simplified a huge amount in the above; some of this stuff is just hard to ELI5 because it relies on fairly advanced physics.\n\nIt should be emphasized that the exact effects of an EMP are hard to model and that there is a split expert consensus on whether it would be a huge problem, not as much of a huge problem, or something in between. "
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3bepbu | when ink fades from paper, where does it go? | What's the actual chemical process that prevents it from staying where it is? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3bepbu/eli5_when_ink_fades_from_paper_where_does_it_go/ | {
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"Ink is a chemical that absorbs light. When ink fades it's not that the chemical left or isn't on the paper anymore. The chemical is still there but the molecules are changed so they don't absorb light anymore. Even a small change in the molecules can make it so that it doesn't absorb light at all.\n\nSometimes people spray some stuff on top of the ink or coat it with something else. That helps it not fade because the spray can block the stuff that makes the ink molecules change. Two things that often make the ink molecules change are oxygen and UV light. \n\nOxygen is a molecule that really likes to attach itself to other molecules. That's why oxygen is used in our bodies to get energy out of food or why it's used in fire to get energy out of burning stuff. Oxygen will attach to the ink molecule and change them a little bit. \n\nUV light is a lot like the light that we can see but it has more energy in each little light bundle. If a bundle of UV hits the ink molecule it can break it a part enough that it doesn't absorb light enough. It's' very similar to what happens when UV light hits our DNA. It can break the DNA which is why UV light is dangerous and can cause cancer; it messed up our DNA just like it messes up the ink molecules. "
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cfm6lx | if e.coli is already present in ones colon, why does it make you sick to ingest? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cfm6lx/eli5_if_ecoli_is_already_present_in_ones_colon/ | {
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"There's harmless e. coli and there's harmful e. coli. The ones chilling in your intestines is harmless. The ones that make you sick are harmful.",
"Different strain of e-coli. The one in your gut is harmless, but the one that makes you sick release toxins hence food poisoning and now you are sick :( .",
"Like others have said, different strain. Cats and lions are both felines but i am only afraid that one of those will eat me while i'm alive.\n\nBut that does not mean the bacteria in your gut is harmless: after you die, the same bacteria will start to decompose you. It takes only about 20 minutes for them to start that task. But what is fascinating about our bodies is that topologically, we are donuts. There is unbroken membrane from your mouth to your anus no matter what route we take. So, in a technical but also very literal sense, the bacteria in your gut is outside of you. This is very important little detail. Your actual inside is totally different environment from the outside. If the bacteria manages to get inside of you, it is a big, big problem. Without treatment, it is deadly. The little things that help you keep alive also can kill you.\n\nIt is a symbiosis between us, the bacteria in your gut helps to regulate your autoimmune system, it can warn you before trouble really hits, there is communication happening. They are part of the digestive system that also controls our mood, energy levels. And there are a LOT of them. One could easily start to think that who is actually in control, we or them. Spoiler: we are but they do have a an important role. Good gut flora can help alleviate or prevent multiple problems, it is very important to have that system working at optimal. Exercise and good diet, lots of fibres and moving a lot.",
"The bacteria in your body typically stay in that part of your body. The E.Coli in your colon thrive there because your colon is \"set up\" to have it there. That E. coli has no business being anywhere but your colon. So, when you ingest E. coli, it ends up in your stomach and small intestine. These organs are not prepared for the E. coli, so they trigger an immune response to get rid of the foreign invader. Stomach starts trying to get rid of it by vomiting, small intestine goes the other direction. \n\nThis is also why the streptococcus pyogenes bacteria causes strep throat, or staphylococcus aureus causes staph infections, despite being essential parts of the body's normal flora. They're your best friends, as long as they stay in their homes, so to speak."
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7gb28s | if your body thinks its eating sugar does it still produce insulin? | i.e. fake sugars | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7gb28s/eli5if_your_body_thinks_its_eating_sugar_does_it/ | {
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"Your body always has a negative feedback approach to different situations, blood sugar is one of them where your body monitors any change in blood sugar, if it goes too high, insulin is produced, too low and glucagon is produced, this happens with every other component in your blood and your body just tries to balance things out but it always a little bit behind.\n\nThat being said, and to answer your question, consuming any food normally would trigger a small insulin response once it enters your blood stream but it would be far less than if you'd have eaten a spoonful of sugar for example ",
"No. The pancrease only undergoes the steps to raise insulin levels upon a stimulus response of glucose within your bloodstream. If its not glucose in your bloodstream then insulin stays the same. "
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1mhbuh | why are jet airplane cockpits connected to the cabin at all? | From a design standpoint, wouldn't it make sense to have the entrance to the cockpit on the exterior of the plane and just have a wall where the door usually is?
That way everyone can board while it's on the ground but once it's in the air it would be impossible to get inside.
Seems like with all the money thrown a the TSA and security we'd consider safer designs too... | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1mhbuh/eli5_why_are_jet_airplane_cockpits_connected_to/ | {
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"It's pretty complicated and heavy to make external doors. Also, in the event of a medical emergency in the cockpit, there would be no way to get help. Modern post-911 airliners have pretty beefy cockpit doors anyway, people getting in there really isn't a problem anymore. ",
"On long haul flights, there is a crew and a backup crew. Each crew flies part of the flight, and has a sleep break at other times. This means that you would also have to have sleeping cabins in the cockpit area. \n\nThese rest areas are shared by the cabin crew, so they need to be accessed by both. Creating two rest areas would be a waste of very precious space.\n\nThere are also times when the cabin crew needs the support of the pilots and vice versa, such as to provide meals.",
"They were originally designed by people who had no notion whatsoever of passengers possibly hijacking the airplane in mid-flight. Also, pilots and co-pilots occasionally need to take a leak, you know.",
"With regard to the security, what we have today (in the form of the structure of the aircraft) is good enough. Pilots are generally in little danger and would not be easily reached should a hijack be attempted due to large doors. This means that situations where the pilots are overthrown are rather unlikely. Explosives smuggled on board are a much larger issue, as it is very hard to stop their detonation once on board."
]
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[],
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|
513avx | why people can snap out of happiness quite rapidly yet people struggle / take longer to snap out of sadness | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/513avx/eli5_why_people_can_snap_out_of_happiness_quite/ | {
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"text": [
"People will snap out of both at about the same rate. It's referred to as the [hedonic treadmill](_URL_0_). Essentially, the human psyche is pretty resilient; when we face new things, we react pretty quickly. But over time we become used to whatever stimulus is present, be it winning the lottery or becoming paralyzed, and we return to a stable \"meh\" condition.\n\nTo get at the heart of your question, it can very well seem like the times of sadness take longer to get used to (habituate to), yet in all likelihood it is taking a \"normal\" amount of time. We tend to easily recall negative feelings more than we do positive ones, and as a result it will seem like sad spells last longer. One potential evolutionary reason for this phenomenon is that being more aware of pain once allowed for a greater survival rate; being able to identify and dislike pain lead to a greater avoidance rate of painful (and frequently deadly) stimuli. (This also plays into why the best news channels frequently show chaos and tragedy while focusing less on charity and fortune. It's what we have been evolutionary \"programmed\" to be attuned to)."
]
} | [] | [] | [
[
"https://en.wikipedia.org/wiki/Hedonic_treadmill"
]
] |
||
7u76jh | how do player trades in sports work? how much input does the player have in the decision to be traded? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7u76jh/eli5_how_do_player_trades_in_sports_work_how_much/ | {
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"text": [
" > How do player trades in sports work?\n\nIt varies by sport, but for a general answer, as long as the teams make a deal with each other, and they don't break any rules the league has about trades (which they generally don't because they know the rules), then its as simple as just two sides coming a deal. It really is that easy.\n\n > How much input does the player have in the decision to be traded?\n\nDepends on the player. In some cases, the player may be involved had have a lot of input. In others they may just go over and tell them they got traded, and done deal. And some in between. In some cases top players even get clauses in their regarding their input on trades involving them, or that they can only be traded at certain times, or to certain teams, and so on. The better a player you are, the better your contract is, the better chance you may get a say in the process, not that you will get a say, but a better chance to."
]
} | [] | [] | [
[]
] |
||
3kfzjk | what does anti-dandruff shampoo do that is different from regular shampoo? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3kfzjk/eli5_what_does_antidandruff_shampoo_do_that_is/ | {
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"text": [
"Pharmacist here. Most common anti-dandruff shampoos contain selenium sulfide which helps decrease the rate of cell turnover AKA slows the rate of your skin flaking off of your scalp, therefore minimizing not only the appearance of dandruff but the amount of flakes that actually fall off. Other anti-dandruff products can also contain active ingredients pyrithione zinc or ketoconazole. The key difference between regular shampoo and these \"medicated\" shampoos is in the active ingredients.",
"So I used to use this head and shoulders shampoo, and it would really help. Uhm, if I ever stopped using it for like a week, dandruff would appear again. This is, thats quite expensive. Now I have lots of dandruff, way more than before and I think that its this psoriasis disease thats causing it, although im not sure. Is there any other efficient product I should try, something to be found in Europe? I will go to a dermatologist in the following months ",
"How do i know if i need 'normal' anti dandruff shampoo like tgel and h & s, or anti fungal shampoo like nizoral?",
"buy a scrub brush, brush your head and beard. no dandruff issues unless i go like 4 or 5 days without a scrub. no chemicals needed. ",
"Dandruff appears to be caused by hyper-sensitivity to a yeast (fungus) that grows on everyone's head. Nizoral is an anti-fungal product that inhibits the yeast from growing on your head in the first place. Some anti-dandruff shampoos have salicylates in them, similar to aspirin. These will topically inhibit the inflammatory response to the yeast your skin hates, by inhibiting prostaglandin production. Others are anti-itch. T-gel has coal tar, which kills the cells in your immune system which attack the yeast. T-gel can also be used for psoriasis on non-scalp parts of the body. \n\nSource: I'm a PhD pharmacologist who has dandruff. \n\nI used to use Nizoral, but couldn't afford it. So, gross as this sounds, I stopped washing my hair at all, and now just use about a quarter size dollop of olive oil and massage that into my scalp. When drying my hair, all the oil comes out, and my hair doesn't look greasy at all -- if anything, it looks a little dry. FWIW, my sister has the same thing, tried the olive oil thing, and it works for her too. \n\nThe stuff that others have posted here is total bullshit. pH doesn't matter. You may have dry scalp which is exacerbated by detergents. All shampoos contain detergents. \n",
"Most anti-dandruff shampoo sold contains pyrithione zinc which fights a fungus that grows on your scalp called malassezia. Malassezia grows on everyone's scalp. It feeds on sebum, the oils produced by skin. Sometimes the byproducts of its consumption of sebum can irritate the scalp which can cause inflammation and flaking. Other active ingredients include selenium sulfide (expensive & rare), ketoconazole (more expensive and rare) and coal tar (smelly and gross)."
]
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[],
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[],
[],
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[]
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||
29c15v | during a game in the world cup between two different language speaking teams, how are they communicating as they do sometimes? | For example, Chile is playing against Brazil and occasionally players from both sides will exchange words. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/29c15v/eli5_during_a_game_in_the_world_cup_between_two/ | {
"a_id": [
"cijfjni",
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"text": [
"For having tried while on vacation in Portugal, speaking Spanish to a Portuguese while he answers in Portuguese will get your point across.\nIf that does not work, you still have English...",
"Most often, they are speaking in English as this is a common second language around the world. Otherwise, much of the communication is uttered in the players native tongue, regardless of the opponents fluency in the language. Body language, mannerisms and facial expressions also send very clear messages that transcend language barriers."
]
} | [] | [] | [
[],
[]
] |
|
cxnzuz | how did they determine the safe viewing distance of the atomic bomb test when nothing like it had ever been done before? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cxnzuz/eli5_how_did_they_determine_the_safe_viewing/ | {
"a_id": [
"eymbzcv",
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"score": [
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2
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"text": [
"A remarkable amount of things regarding the development of atomic weapons was guess. Is this far enough, hope so. This glass dark enough, sure. Will this block the radiation probably.\n\nThe first nuclear reaction in Chicago in 1942, there was some debate if it would set the whole atmosphere on fire and burn the planet. ( Spoiler it didn't)",
"Calculations: you know the molecular weight of uranium, you know the enrichment rate, you know the total mass, and without provoking explosions they had studied fission, so they knew what energy to expect per fission event. They went through a whole lot of very hard and expensive work based on the theoretical predictions of critical mass and detonation power, so they did have good estimates of energy release and type of radiation and byproducts expected. If the calculations were wrong, the most likely outcome would just be a lack of explosion rather than a bigger explosion."
]
} | [] | [] | [
[],
[]
] |
||
ujlaw | what is the different between cc-ing somebody and putting multiple people in the "to" part of the email? | If you don't understand what I meant, [here](_URL_0_) | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/ujlaw/eli5_what_is_the_different_between_ccing_somebody/ | {
"a_id": [
"c4vxy4r",
"c4vy53t"
],
"score": [
2,
29
],
"text": [
"CC: eliminates the confusion of someone getting the e-mail, reading the first line, and deleting it because it wasn't meant for him. An example, In order to take vacation time, I need to send an e-mail to my supervisor. When I send that e-mail, I CC it to my subordinates so they will know when I will be out of the office. If I included them in the TO line, one would forward the e-mail to my supervisor thinking I had sent it to him by accident. ",
"People in the To: field are required to respond or take requested action. Those in the cc: field may find the email informative but are not required to respond or take action. That's how we generally use it in business. "
]
} | [] | [
"http://imgur.com/fnY8T"
] | [
[],
[]
] |
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