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5tg7zp | what happens to sleepwalkers in space? do they move about? | I was wondering whether somebody that frequently sleepwalks on Earth could possibly move about in space? As they would have adapted to moving about in zero gravity would they now apply this new skill and instead use this?
Also, would their sleeping bags anchor them in to stop them moving and only allow wriggling? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5tg7zp/eli5_what_happens_to_sleepwalkers_in_space_do/ | {
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"They would be strapped down when they sleep regardless of whether or not they're a sleepwalker. The reason for this is that in space even the slightest turning around in your sleep would cause you to float all around the cabin, and that would be bad because you might hurt yourself bumping into things. They also need a way to keep you still so that they can guarantee the fan gets to your face so you don't suffocate."
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1ocz5y | reciprocal altruism | Both in the natural sense and the human, please. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1ocz5y/eli5_reciprocal_altruism/ | {
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"Here is an interesting Wikipedia article: _URL_0_\n\nSince I don't know what point your starting from ill start from the simplest. Altruism is the practice of being concerned with another persons welfare. Reciprocal means going both ways.\n\nSo in nature, an organism that helps another organism hopes that the organism that is helped will return the favor.\n\nIn the human sense it means that you are doing someone a favor and hope that they will return that help later when you need it."
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aj9hk6 | why after a long train trip, when the train stops at a station, do i feel like the train (and me) are moving backwards? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/aj9hk6/eli5_why_after_a_long_train_trip_when_the_train/ | {
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"Relative motion.\nYou get used to the motion of the train, and that motion becomes the kind of calibrated as \"still\". Then after you stop moving your internal motion sensors are giving you wrong information until they recalibrate. It's basically the exact same reason the room spins after you twirl in circles. ",
"Dump a little water in a glass, now slide it across the table, like you see the bartender do on TV or in the movie. Now watch the water in the glass. \n\nWell the glass is sliding in motion, the water is naturally going to settle inside the glass and basically fill out the bottom. However when it comes to a stop the container may stop while the water keeps pressing forward, only to wind up sliding backward the same amount.\n\nEspecially in instances where a second actor is there to stop the glass(abruptly) when it reaches a certain point, the liquid in it is going to slosh forward a bit, then back, hard. \n\nYour inner ear, has fluid in it, and this is what helps you find your balance. It does the same thing as the water in that glass when it sloshes back-and-forth coming to a sudden stop."
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d273fj | even if no changes were made in the first place, why do word/powerpoint and similar software ask only sometimes if i wanted to save changes made? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/d273fj/eli5_even_if_no_changes_were_made_in_the_first/ | {
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"It's hard to answer this question generally, as it's kind of akin to asking why my car doesn't turn on, there are a myriad of possible causes that are consistent with the behavior. While I'm a developer, some of this is speculation, and just based on my own hunches.\n\nApplications that work with files have very few options or behaviors that don't affect files, as such I don't think they code explicitly that this option needs a file save, it's sort of automatic where they look at the structure of the file in memory and maybe a flag is tripped when a mutation is performed.\n\nSo what are some things that could mutate the structure in memory without you doing it, and would appear sometimes.\n\n1) If you open a file from a different version of the Software. Word and Power point in particular may be able to parse a general format but save in a slightly different way that looks the same. For instance they could change compression algorithms that shrink the document and it would be the same document uncompressed, but it could require a change. Or it could be something like this version uses metric, and another uses imperial for internal document format.\n\n2) You could have plugins etc that embed data in them that need updates. Word and Powerpoint in particular can embed other things in them, and those other plugins could potentially be registering as changes, or be changing content that you don't see.\n\n3) Something automatic like Macros could be changed or updated in the document and when you open on this computer it updates the document. For instance (and I'm not saying that you have one, and would find it very surprising), but if a computer was infected with a virus that exploited a piece of software it might change the document every time and prompt you to save.\n\nThose are just three reasons I could think of.",
"Just because you didn't change anything doesn't mean nothing was changed. Both these programs have sophisticated macro programming capabilities. Maybe you don't realize that you are using them, but that \"date\" box on the bottom of your powerpoint slide is updated by a macro. Sure, it might show the same date as two hours ago, but the macro ran, removed the old date and inserted the current one. That's a change, and it marks the file dirty, so you're asked to save it when you quit/close it."
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6mgklt | what are fumes and why do they appear to warp light (eg. from gasoline of butane)? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6mgklt/eli5_what_are_fumes_and_why_do_they_appear_to/ | {
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"They appear to warp light because they're warping light.\n\nThis is called [refraction](_URL_1_), and is caused by changes to the light itself as it moves through different substances.\n\nFumes are caused when a solid or liquid substance turns to gas via [evaporataion](_URL_2_) or [sublimation](_URL_3_. Because these fumes are made up of different chemicals than the surrounding air, they refract light differently.\n\nThis also happens because of temperature differences, and is the reason why hot cars make the air around them \"shimmer\", and is also the cause of [mirages](_URL_0_)."
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8yljem | - when a program or game has a bug, how do developers track it down? | This is more about games.. when a bug is found and needs to be patched, is there an easy way of tracking it down based on what it is? Or is it just luck? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8yljem/eli5_when_a_program_or_game_has_a_bug_how_do/ | {
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"Through a tedious process called debugging.\n\nBasically you run the program one step at a time and check where is it malfunctioning.\n\nFor example if you had a bunch if math operations and you checked the results one at a time you could see that X*X=Y instead of X^2.\n\nThen you could fix whatever code is causing the malfunction.",
"Depends on the bug. If you're lucky, the bug is associated with an error in the log, which will tell you exactly where the error is happening and gives you a good idea of what code you need to be looking at to fix it. If you're unlucky, you'll have to go through a tedious process of elimination--is it a hardware issue, is it a network issue, is it a problem in the UI layer, is it a data issue...I'm simplifying, but basically, you look at the bug and make a list of all the things that *could* be causing it and carefully and thoughtfully run tests to eliminate each as a possible cause. Depending on the bug, that process could take days or months to complete, which is why sometimes companies just decide not to fix it."
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3psag9 | why do most areas in america have counties and cities that overlap each other? | So if you are driving through a largish city (a metro area), you may drive over a county and then over a city into another city or county. And just looking at schools and police activity. A county police department have a larger force than a city force. You see police for Countyx police. And then you may have schools that say Cityz schools.
Why is there always that overlap and when do services and restrictions end? And why not simplify that? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3psag9/eli5_why_do_most_areas_in_america_have_counties/ | {
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"The country is divided into states, states are divided into counties, and counties are divided into towns and cities (with some areas that are \"unincorporated\"- not part of any town or city). Counties generally don't provide many services, but when the county has unincorporated areas, they have to step in and provide the services normally provided by the city, such as police.\n\n It's not uncommon for all of the cities in a county to work together for things like schools and public transit because it doesn't make sense for each small town to run its own transit system, and running a larger school network can allow for schools to specialize.",
"It's pretty rare for a single city to cross county lines. The only one I'm aware of is New York which covers the entirety of 5 counties.\n\nVirtually the entire country is covered by counties. Louisiana has parishes instead of counties, but as far as I can tell, the difference between parish and county is the name. There are some independent cities, Baltimore for example, that operate as if they were a unified city and county."
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3f9qxz | after a person is in the ocean and being moved around by waves, how does their body continue to feel this sensation of being tossed by waves long after they have left the water? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3f9qxz/eli5_after_a_person_is_in_the_ocean_and_being/ | {
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"Your brain tends to turn off or suppress senses that are experiencing the exact same input for long periods of time, much like staring at a flat color until it seems dull, then when you look away you can see it's inverse.\n\nAfter a while of repetitive rocking motions on the waves you just get used to it, your brain reprograms this to be the norm. When you step off onto land you feel the inverse until your brain re-adjusts to that."
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449hnm | what causes the air to move slower under a planes wing? | Or more or less, how come air moving across a flat surface is slower than a curved one. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/449hnm/eli5_what_causes_the_air_to_move_slower_under_a/ | {
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"The short answer. It doesn't. It moves at the same speed. What creates flight is relative densities of the air above and below an airplanes wing. The curve shape of the top of the wing pushed air out of the way while the flat shape underneath allows air to flow underneath. This creates more density underneath than there is above. This causes the air to move up to fill the empty space lifting the plane with it in the process."
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2pft7n | why the sell-by date is not the expiration-date. | Eggs for example. Why have a date that says "Sell-by two weeks from now" if I can properly refrigerate them and make them last another week and a half? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2pft7n/eli5_why_the_sellby_date_is_not_the_expirationdate/ | {
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"1) people generally keep things for a few days once it has been bought - hence shops need to sell and item by a certain date so that it isn't bad by the time you use it\n\n2) stock control - you have to order and sell items in a certain timeframe otherwise the next order will overstock you\n\n3) people equate \"sell by\" and \"use by\" and \"not edible\" dates meaning the same. Throw away good food and buy more. $$$ for the supermarkets. "
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9iwwsr | why/how do wild animals always look clean? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9iwwsr/eli5_whyhow_do_wild_animals_always_look_clean/ | {
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"Most animals spend a lot of time cleaning themselves, by for example licking themselves. Humans apparently don't like licking themselves, so pretty much their only option is to go in some water.\nAlso, fur often takes more dirt to look dirty than bare skin, since there are many layers where the dirt can go unseen",
"They are very dirty. Go brush a wild horse (if you can get it to stand still), or feel the pelt of an animal that was just hunted, or just look at anyplace a raccoon has been. Their fur hides the filth."
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1mxh03 | why unlike other germanic languages english lacks the "ch/sch" phonetic like in german/dutch? | I don't know what linguists call this phonetic, but it's the ch/sch for example in Dutch/German or the j in "Mujer". *i know Spanish isn't Germanic but useful example since more people know Spanish* | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1mxh03/eli5why_unlike_other_germanic_languages_english/ | {
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"English used to have it - it's a voiceless velar fricative. It was spelled \"gh\", but over time changed to either became silent (taught) or shifted to an f sound (tough).",
"Armchair historio-linguist here; My guess would be that exposure to the 'longer' vowels of Norman/French kind of polished off the fricative sounds, since it's hard to make the mouth move that way- an 'och' sound would have become an 'ohh' or 'aah' or 'auh' sound- more breathy. \n\nI learned Old English to read Beowulf, and have an okay Chaucer accent. "
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22968w | what is "new journalism" as opposed to regular journalism? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/22968w/eli5_what_is_new_journalism_as_opposed_to_regular/ | {
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"New journalism can add the journalist into the story as a character. New journalism can use literary techniques to tell a story. New journalism doesn't adhere as closely to the facts as regular journalism, but strikes more at the \"truth\" of the matter. That is to say it's more \"true,\" which is hard to understand until you've read quite a few examples. It certainly makes for a more entertaining experience, which may help in getting the news/message out (think Jon Stewart/ Stephen Colbert). \n\nTom Wolfe, Hunter Thompson, Truman Capote, and Ted Conover are good places to start hashing out your definition of what \"new journalism\" means to you. \n\nEdit: added emphasis"
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1pj6di | - some countries have profoundly benefited from limiting or eliminating their military spending. the us spends more on the military than any other economy. why has it continued to do so well economically for so long? | Costa Rica decided to stop military spending after WWII (it isn't that simple, but we are five year olds here). As a result of investing in education, health care, and basic infrastructure, they have become much better off economically than their neighbours.
Germany had to limit military spending after WWII and has done well economically as a result. Japan has a similar story.
The US is the strongest economy but behaves in a way that is opposite to the above examples. You can cite imperialism, in which one spends to overpower and seize resources, but this must have its limits. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1pj6di/eli5_some_countries_have_profoundly_benefited/ | {
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"There is no single right answer in economics. Each country plays to its own strengths based on what resources are available to them, what technology they have access to, etc.\n\nAs it so happens, the US is the world's main supplier of weapons, planes, etc. Manufacturing these things creates a lot of jobs in the US, so by increasing military spending, the government is basically able to pump money directly into the economy. In other countries, they would not be creating weapons, but importing them from the US, so it doesn't make as much sense to have the exorbitant defense budget there as we do here.",
" > Germany had to limit military spending after WWII and has done well economically as a result\n\nI would very much argue that Germanys economc success has very little to do with military spending. Do you have something to back up this claim?",
"Well, honestly this is a tough question, one that I've been talking about a lot recently for some reason, so I wanna share some of my thoughts and start at a pivotal point in history - The Great Depression. \n \nBecause what brought America out of The Great Depression? WW2. Suddenly there was a high demand for production and lots of work to go around. Other factors, like not being involved as long as other countries, meant America hadn't spent itself to ruin like England or Germany. In fact, though the years of post-war rebuilding would see a boom for many countries, America was about the only country to *end* the war in better shape financially. \n \nSo at this point in history, military spending took America from it's worst financial troubles in history to making it the strongest economy in the world. That's gonna impact how said economy functions. \n \nThe economy, really, has been riding a military wave since then. The military and institutions that support it are a huge source of jobs and money for Americans. Military spending isn't a *hole*, it gives people their livelihoods. When you buy American tanks, you pay the factory workers' wages. When they stock up on MREs, they support the farmers who grow the food and the plants that process it. The millions of military employees who's paycheck is covered by military spending use it to do everything from pay rent or buy beer. \n \nThe simple fact is that it just *works*. They could cut military spending, but you'd likely have a rut right after where all the people who relied on the military industry for a livelihood find themselves out of a paycheck. I mean you can pump that money into schools, but a factory worker can't be trained into a teacher overnight, there will always be a period of adjustment when you re-focus the economy. So instead of knocking the economy off kilter, it's more stable to just keep things going as they are and keep riding the wave. \n \nOf course you could argue that it would be worth it, but that's not my point, I'm just illustrating that historically the American economy has relied a lot on it's military spending.",
"It's not that we do better because of our military, its that our economy is so robust that it can support a military the size of ours. \n\nThe reason other countries have smaller military spending (post WW2 Germany and Japan for example) is because of \"pax americana.\" US military might subsidizes the defense of all of our allies so they can spend less and still be protected through allying themselves with the US. \n\nThere are some fringe benefits - engineering and science advacements through military spending, but the big benefit is that the world is incredibly stable thanks to the US subsidizing the defense of the world through its military spending and projection of power.\n",
"If you want to assume this, you first need to show these things:\n\n* Does the US really spend more than any other country from a *relative* perspective?\n* What's the economic multiplier of military spending.\n* How did countries benefit from limiting defense spending? Did the change in allocating resources mean they spent their money on items that gave higher economic multipliers?\n\nAs a percentage of GDP, Israel's military spending is higher than the US. So is Russia. And Saudi Arabia. Their economies are doing well too. \n\nFrom those, Russia and Saudi Arabia do well because of energy. Israel has a very educated workforce. The US has a very educated workforce and an attitude that allows for dynamic and creative businesses and universities. \n\nIn other words, it seems the economic multiplier for military spending is likely close to 1. Meaning that there doesn't appear to be much of a net gain or net loss by having some government money go to defense spending. \n\n\n\n",
"You might think that if politicians made changes for the better for the majority of people they would get more votes, but that is not necessarily true. For instance if they reduce government spending that might make a very small improvement for most people, but the displaced people who lost their jobs are likely to actively campaign against them and could lose them a net number of votes.\n\nIt's much more effective to buy votes with slick advertising than to make marginal improvements. They take campaign financing from the lobbyists to buy the advertising. For instance the military industrial lobbyists spent more on campaign financing in 2008 than Obama and McCain spent on their entire campaigns combined. Obama had originally extolled the virtues of ending the war, but if he had of stuck to that position all of that campaign financing would have gone to the other side and Obama wouldn't even have got the nomination, let alone get elected. \n\nPeople can complain all they want about corrupt politicians or evil lobbyists, but both are doing as we have designed them to do. The fault lies with the people who allow their votes to be bought by advertising and pundits. Most politicians would much rather people band together and vote in their favor based on their good work rather than have to rely on campaign financing. \n\nedit: missed a word",
"A lot of these countries are able to reduced their military spending *because* of the US.\n\nJapan and Germany have treaties with the US and US military stationed on their soil. Costa Rica has a few thousand US military personnel stationed there doing drug intervention.\n\nThese countries would most likely have larger military expenditures if not for their relation with the US."
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6c4sr2 | how can a company like kmart / sears still have a stock value of hundreds of millions of dollars when they haven't made a profit in ten years and are technically bankrupt. | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6c4sr2/eli5_how_can_a_company_like_kmart_sears_still/ | {
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"Sears current Market cap is $830m. They have about 1400 stores between K-Mart and Sears. That comes out to a value of less than $600k per store. That's probably LESS than the value of the real estate they hold, the inventory in the stores and the fixtures, computers, etc. they own in the stores.\n\nThe ongoing business entity may very well have negative value and the entire value in the company is its physical assets.",
"Because stock value is often related but not actually determined by the assets, cash flow, or profits of a business. When someone buys stock in Sears, they are buying a (very) small ownership stake in the company and speculating that their ownership stake in the company will increase in value in the future. \n\nThe people currently holding/buying stock in Sears might believe (based on new leadership, a new product or policy, new markets, market position, or any theory they might have) that the company will eventually correct course and rise in value, at which point they can sell the shares they are holding for a profit. Less optimistically, they might recognize that there would be some value to Sears competitors to buy the company out (an immediate infrastructure for expansion, an outlet for new brands they are invested in etc), and be betting that a competitor will offer them more per share if a takeover or buyout occurs. Here the price of the stock isn't based on the return the company can make for itself or pass on to shareholders directly, instead the price would be influenced by the value a sale of the company could bring to a buyer.\n\nIt is also possible that the stock price is based on other factors that are more valuable than store profit. For example, Yahoo was recently assessed by most industry experts as having an almost worthless core business, but they had made significant investments in Alibaba (basically the Chinese Amazon) and other companies which were performing very well. In that case, the value of yahoo stock was based more on it's holdings in other companies than in its direct ability to turn a profit.",
"There's a certain amount of value in the names alone. Well, in the Sears name, anyway. Even if the company is liquidated, someone would want to buy the rights to the Sears company, and perhaps relaunch the brand.\n\nThe news won't necessarily report on some upstart store brand. The news will absolutely pick up stories about the \"new Sears,\" and free press and good will has value."
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2mss3w | how can monopolies like duke energy operate so smoothly and monopolies like comcast operate so poorly? | I don't get it.
Large capital corporations have plenty of money. Wouldn't it be logical that they should also have 1) more money for training 2) more staff to service clients and 3) more resources for research and improvement? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2mss3w/eli5_how_can_monopolies_like_duke_energy_operate/ | {
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"Energy companies are legally classified as utilities, and as such are subject to more regulation than a telecom like Comcast. Long ago, the government decided that electrical service was vital enough to our society that the companies that provide it need to follow a bunch of rules in order to help ensure consistent and useful electricity supplies.\n\nThis is one reason why big ISP's like Comcast are fighting so hard not to become classified as a common carrier, they don't want to have to deal with more stringent regulations."
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5xzfjd | what is aws (amazon web server) and what are the basic things one should know to understand how it functions? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5xzfjd/eli5_what_is_aws_amazon_web_server_and_what_are/ | {
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"AWS stands for Amazon Web Services to contrast their shipping services. It is a collection of services that Amazon provides online. These are things like storage, backup, DNS, database, load balancing and maybe the most popular, virtual machine hosting. The concept about all this is the economy of scale. Amazon will build huge data centers and engineer them to provide the kind of services that most businesses need. Since they do it on a huge scale they are able to do it cheaper then if every business were to build their own from scratch. There are however lots of disadvantages like needing a lot more spare capacity and having to build something that fits everyone as opposed to something that fits a particular user. So it depends on the use case if you save money by using their services as opposed to making your own from scratch.\n\nOne of the most revolutionary benefits that AWS brought into the market is that purchasing additional capacity is much easier and faster. You might have taken weeks to buy hardware and install it at your location. Or if you are renting though traditional suppliers you might take a few hours to let them manually reconfigure things. However AWS made everything automatic so you can get a new server within seconds. This have allowed businesses to build their applications to allow them to scale on demand. This means that they pay different amount of money for the services depending on how much they use. This have the ability to reduce costs but it again require more time to develop and maintain the more complex applications.",
"When navigating to \"_URL_0_\" in your browser, first thing you do is asking the DNS server \"Where is _URL_0_?\" Then it will redirect you to the IP address of the server, and you'll request \"Can you give me the homepage, please?\" On that server - think of it as a regular computer - there's a program that receives the request, looks up all the necessary data in the database - a hard drive-, and sends you back the webpage. \n\nSince Amazon has thousands of those servers and huge databases, they get a nice deal on their infrastructure price. Using this discount, they decided to buy even more servers and database space, and make it available to other people who want to host a website. So Amazon gets all the resources (server, database, internet connection, DNS registration, ... ) at a nice bulk discount, much cheaper than when you had to do this all yourself. \n\nUsing AWS means you're renting some of that server space. Now you're not getting an entire server for yourself, those are way to powerful for just one simple website. So they use virtual machines to share the hardware. These machines act like individual computers, each with their own operating system and hard drive space. ",
"You can think of AWS (Amazon Web Services) like a supermarket that sells different products. Long before there were any supermarkets people would have to milk their own cows and bake their own bread. The problem with having your own cows is that you have to feed them and sometimes they get sick. They also probably produce way more milk than you require. With a supermarket you only purchase the amount of milk and bread you require and you don't have to grow your own cow or bake your own bread.\n\nBefore AWS, most companies would maintain their own physical servers in a data centre. With AWS you can purchase the servers you require and no longer have to maintain physical hardware. Like a supermarket, AWS sells different products/services to solve different needs."
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2diyxt | why do zookeepers and animal workers wear green? | Every zoo I've ever been to all the keepers wear green, same for all the veterinary nurses I've seen in the UK. Is there any reason for this? I suspect it's that green is a calming colour, but that's just a guess. My girlfriend asked so if anyone can help thanks. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2diyxt/eli5_why_do_zookeepers_and_animal_workers_wear/ | {
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"Green is a natural, soothing color that animals are always seeing. For example, they do not often the the color red in the wild unless hunting (thought: kill, eat!) or their own blood from being attacked (danger!) so depending on the animal a specific color could cause them to react in a specific way.",
"I think its just for people. Honestly aside from certain colour perceptive species, most animals are colourblind. Not to say that they cannot altogether see colour, but that their colour vision is restricted compared to ours. They may not be able to distinguish red-green, blue, yellow etc. Plus colour cues can be so different for different species. Red in one species might instil a flight-or-fight response, where in another it is a sexually attractive colour. Green is a pretty natural and neutral colour but there is no reason why they might not choose blue, black, white, yellow etc.\n\nOur zookeepers wear tan/kakis and I think many in North America do. ",
"we wear blue because of the look. i think most zoos wear green to sandy olive colours because of the public perception of what an explorer would be. _URL_0_ also it's a nice neutral and natural looking colour so the keepers blend in to the background and don't stick out in enclosures whilst doing rounds or maintenance. "
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2basyu | how would the internet work on an interstellar scale? | What I'm trying to say is if we use something like optical fiber connections across an array of solar systems, would editing a website in one solar system take however many lightyears away it is from the next one is to be seen? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2basyu/eli5_how_would_the_internet_work_on_an/ | {
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"It would. The closest star to our own is over four light years away. The fastest **any** information can get there is 4 years and a bit, and then that long again to confirm receipt or reply. Networking on such a scale won't ever be feasible. ",
"That is correct. No information can travel faster than the speed of light, and so any \"universal internet\" would only update that fast.\n\nIn other news, aliens on the planet Kepler 9b just updated space-Reddit to find that Jesus has just been crucified.\n\nEdit: Due to the amount of people responding to this with \"quantum entanglement\", let me just remind you that, as far as we can tell, quantum entanglement does not allow for communication of information. Please see \"No-Communication Theorem\" for more information.",
"As things stand now : yes.\n\nBut if we have figured out interstellar travel, perhaps we will have also worked out FTL communication.",
"There's a science fiction book by Vernor Vinge that explore this a bit. A Deepness in the Sky.\n\nIIRC they send and receive messages at light speed and are basically unreachable when far away. They do employ networking locally. They travel often at reletavistic speeds in cold sleep so people will end up all over the galaxy and being older than their grandparents and all kinds of weird stuff. Nice sci fi read if that's your thing and there's another one called A Fire Upon the Deep to which this one is actually a prequel. In that one they do have FTL speeds and communication. ",
"Everyone is saying \"yes\" but in fact, **no is the correct answer**. It would take **decades, perhaps centuries** for it to be seen.\n\nAlpha Centauri is 4.37 light years away from our sun. For convenience in this example let's just round it to 4.5 light years. Here on Earth I post this message on Reddit, but my reader in Alpha Centauri hasn't seen it yet because he hasn't visited the page yet. So he types in the URL to this post and the query is sent from his computer to the server on Earth; that query would take 4.5 years to arrive on Earth. Then reddit's servers would send the page back to him, adding another 4.5 years to arrive back on my reader's screen.\n\nSo, nine years, right? Well, no. On the modern (current day) internet queries are sent to your computer from servers all over the place, especially in the realm of advertising. So while your computer sends a query to a given web site, your computer may get queried a half dozen times or more before you get the page you requested, updating tracking cookies and all that crap while you browse. And your computer has to respond to each of those queries in turn. So let's say my Alpha Centauri reader visits my post that has a conservative three other servers linked to it via advertising engines and the like. Assuming there was only a single inquiry from every associated server (which isn't often the case) the traffic pattern would work out thusly:\n\n1. Alpha Centauri PC to \"main\" web server: 4.5 years\n2. Advertising server #1 to Alpha Centauri PC: 4.5 years\n3. Alpha Centauri PC to advertising server #1: 4.5 years\n4. Advertising server #2 to Alpha Centauri PC: 4.5 years\n5. Alpha Centauri PC to advertising server #2: 4.5 years\n6. Advertising server #3 to Alpha Centauri PC: 4.5 years\n7. Alpha Centauri PC to advertising server #3: 4.5 years\n8. \"Main\" web server to Alpha Centauri PC: 4.5 years\n\nSo that's 36 years just to view a single post on a single page, right?\n\nWell, again, no.\n\nThe web's backbone is TCP; every web page works over a TCP stack. It could be argued that for long distances like the Alpha Centauri run you'd translate everything to UDP since it has lower latency and overhead but that's a conversation for another day. But you'd have to deal with TCP's latency and error detection, particularly when traveling through the nether regions of outer space. Every time a TCP packet is received its checksum is verified. If the checksum passes, the packet is assumed good and life goes on. But if it fails, a request to resend that packet is sent and the process begins anew for that packet. So if your web page request has a perfect transmission you're looking at 36 years of communication, but for every imperfect packet transmission you're adding another eight years to the process. Even terrestrial internet generates enough imperfect packets to \"clog up\" network switches; imagine what would happen when you have to deal with trillions of miles of fiber, radiation belts, astronomical anomalies, and who knows what else.\n\nOf course, this all assumes that all systems involved — server, client, network switches, etc — never suffer any crash, update, power interruption, or other issue that would break the connection, and that the servers and clients have enough chutzpah to adequately manage a packet network transmission with the lifespan measured in years."
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1qpm18 | why "next gen" graphics aren't as impressive as they were last time. | Maybe it's because I was in fifth grade when the last consoles were released, but I remember thinking they looked much much better than they had been. I am really underwhelmed with how the new games look. Was it just my (more) immature mind, or was there really a bigger leap in performance? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1qpm18/eli5_why_next_gen_graphics_arent_as_impressive_as/ | {
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"Partially because of [this](_URL_0_).",
"It's a bit of both. \n\n- PS1/N64: Wow, the game is actually in 3D, you can move around in any direction just like real life! Holy shit! Never mind that Link's face is just 25 triangles, we're in 3D!\n\n- PS2/etc: Wow, not only is it 3D, but there's lip sync, sophisticated character animations, objects go flying when they're exploded or knocked, characters have individual faces, etc! Not mindblowing, but a huge step forward.\n\n- PS3/etc: Wow, now you can actually see individual blades of grass on the ground, and the wind blows the trees, characters have believable facial animations, you can see things reflected in the water, this looks pretty realistic, that's cool.\n\n- PS4/etc: Wow, now the surface of the rubber tires actually looks rubbery, when I run on the ground it leaves footprints and kicks sand up, skin stretches and looks more real when he opens his mouth, their clothes are all billowing realistically. Looks pretty real, neat.\n\nAnd the next generation will seem even less impressive, and the next even less impressive than that, etc. It's just a result of the fact that going from 'pretty damn realistic' to 'really damn realistic' is just cool, not mindblowing like going from 'squares arranged in a vaguely human shape' to 'actual 3D models with voices' was, or like going from 'jagged plasticene humans' to 'believably animated humans with motion-capture animation' was. Every generation of improvements from now on is just going to be improvement in fine details, not radically new ways of seeing models and the game world.\n\nIt happens with all technologies. VHS to DVD was a huge deal, DVD to BluRay wasn't as important to most people, and barely anyone is excited about 4K now. People loved going from cassette tape to CD, but no one gives a fuck about SACD/DVD-Audio. "
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8ea15x | what causes a speech impedement such as a lisp, and is it possible to learn to speak without it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8ea15x/eli5_what_causes_a_speech_impedement_such_as_a/ | {
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"When I was five I had a lisp and so my parents sent me to a speech therapist. As I recall, they taught me how to make certain sounds with my mouth and that slowly transitioned into words. So for me it was relearning tongue muscle memory. It hasn't been a problem since",
"As far as I know a lisp is caused by your tongue being too long, therefore touching your teeth while you speak. You can learn to control this though with therapy.",
"I also had a speech impediment when I was young, and learned to overcome it with speech therapy. It didn't take very long (just a few weeks of therapy). \n\nLater on in life, I had to have many teeth taken out and developed a speech impediment yet again due to the shape of my mouth changing, and I had to relearn how to speak all over again when I was 30. Took a lot less time than when I was young.",
"When making the s sound, your teeth are supposed to be closed or nearly closed. If your tongue is a little too large for your jaw, it can be hard to keep your teeth together, resulting in a th rather than an s.\n\nThis can be corrected through speech therapy, where you essentially practice putting your tongue in the right place. Sometimes it can be corrected with surgery, but that will usually only be done if the small jaw is causing other problems. ",
"I had a lisp. There was nothing wrong with my mouth or tongue. It’s just that to me, the “Th” sounded sufficiently like “s” that I though i was making that sound. There’s a bit of a whistle of exhaling air when you make a “th” sound. I went to a speech therapist who shows me how to make the sound, how to move my mouth and tongue, etc, and to distinguish the sound properly. And that made the problem go away."
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djq09v | how does the skin on your feet get harder and thicker the more you walk barefoot on harsh ground? | I know people who have no problem walking on places most people would never think of walking on barefoot, been wondering how developing hard feet works. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/djq09v/eli5_how_does_the_skin_on_your_feet_get_harder/ | {
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"When you walk on harsh/hard ground, your weight is applied only to your feet, namely to tissue on the ball and heel of your foot. In addition, the rough terrain can act like sandpaper on your skin. Your body then goes to repair the tissue. When it repairs it, it builds new skin layers. So now you have scar tissue and new tissue. Of course the scar tissue is micro formed. Simply, your body forms calluses across your feet to protect your foot tissue. \n\nGuitar players form calluses on their fingertips which help when holding down strings. Some people will develop calluses on their finger if their pen/pencil rests on that finger when writing. Runners may develop calluses on the back of their heels from where their shoes rub. \n\nIt’s similar to how you form a blister if the skin is burned of receives a lot of friction within a sort period of time. A callus forms in the presence of steady, regular, moderate friction, as a way of preventing blisters and injury.",
"Skin, as the rest of your body is amazing at adapting.\nCallus(or hard skin) is usually a result to excessive pressure or friction as a natural mechanism which offers protection.\nSo basically, the more you expose your bottom of your foot to pressure and friction, the more your body thinks they need extra protection and create more callus."
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4mklsw | how do some plants mimic insects for camouflage when the plant has no way of seeing the insect? | How can the plant possibly know what to replicate and then manipulate its own DNA (or whatever plants have) accordingly? I think the scientific term is Pouyannian mimicry but I'm interested in knowing how it's possible for plants and even animals to do this. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4mklsw/eli5_how_do_some_plants_mimic_insects_for/ | {
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"It's just evolution. The plants don't do it on purpose. Rather, the plants which *by accident* have a hard-to-see appearance tend not to get found and eaten, so they tend to produce more offspring.\n\nThis is a version of *natural selection,* the key discovery of Charles Darwin.",
"Your response to another comment explains what happens. The plant doesn't see the insect and then manipulate its own DNA to imitate what it sees. It has an appearance that looks sort of like one type of insect, and also emits scent that attracts that same type of insect. The plant doesn't vary this behavior for different kinds of insects, and nothing suggests that it does anything on purpose. ",
"This is a really interesting question – the fact that some animals and even plants can actively change to mimic their environment or other organisms is incredible. \n\nBut a plant doesn’t need to see something to mimic it. Neither does an animal for that matter. Let’s look at an example: consider the cuttlefish (a color-changing expert). \n\nIt’s easy to assume the cuttlefish sees a patch of red and white coral (for example) and decides on the spot to change its own colors to red and white. BUT a cuttlefish for the most part can’t see itself, so it can’t really see what color its body is. Besides that, [cuttlefish are colorblind](_URL_0_), so they can’t see the colors some of their predators can. Clearly, the cuttlefish isn’t seeing a specific color and choosing to mimic it as it sees it. So what’s happening?\n\nSignals. The cuttlefish receives a signal – in this case, a visual one (maybe combined with signals of a nearby threat) – and that incites an instinctive reaction that causes its skin cells to change, displaying a different appearance.\n\nThe same is true of the plant. That study you linked about the [mimicking vine](_URL_1_) (fascinating!) has a couple of references that showed how plants can receive chemical signals from each other, which can spur changes in their structure or activity. In the case of that vine that mimics its plant hosts, the vine is picking up on a signal (probably chemical) that causes it to change the appearance of its leaves. As with the cuttlefish, the way in which the leaves react to that signal is something that was built into its instinct by natural selection. "
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ligw1 | the difference between small block, big block and hemi engine. | watching Top Gear recently and hear Clarkson say something and I realized that I have no idea what the difference between the 3 is, I know that dodge uses hemi exclusively. Any help is appreciated! | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/ligw1/eli5_the_difference_between_small_block_big_block/ | {
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"Basically, big block engines were more powerful, because they had to keep up with the size / weight progress of cars throughout the years.\n\nSmall block engines are less powerful, and are for lighter cars.\n\nHemis are named after the hemisphere shaped combustion chamber, that supposedly is the best at burning fuel. ",
"Big Block engines use a larger engine block size than small blocks. Think of it as an ice cream cone. The bigger the cone, the more ice cream (dispalcement) it can hold. A hemi engine refers to the shape of the combustion chamber. Instead of a cone, you have a bowl which fits the icecream perfectly. A hemi head is completely round and matches the shape of the fuels combustion much better than a standard head. ",
"Basically, big block engines were more powerful, because they had to keep up with the size / weight progress of cars throughout the years.\n\nSmall block engines are less powerful, and are for lighter cars.\n\nHemis are named after the hemisphere shaped combustion chamber, that supposedly is the best at burning fuel. ",
"Big Block engines use a larger engine block size than small blocks. Think of it as an ice cream cone. The bigger the cone, the more ice cream (dispalcement) it can hold. A hemi engine refers to the shape of the combustion chamber. Instead of a cone, you have a bowl which fits the icecream perfectly. A hemi head is completely round and matches the shape of the fuels combustion much better than a standard head. "
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2bbggj | why don't we have a "microwave" equivalent of a freezer that could take a beer, or whatever, down to zero degrees in 60-90 seconds? | I mean that would be super convenient at parties and before going to the beach.
**Edit:** Getting lots of cool answers including the explanation of why adding energy is easier than subtracting it. Also the **blast chiller** is cool. but this was not meant to be limited to chilling drinks other applications would be quick freezing meals before hopping in the car on a long trip etc. Thanks, reddit. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2bbggj/eli5_why_dont_we_have_a_microwave_equivalent_of_a/ | {
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"It's much easier to quickly add energy than it is to quickly take it away.",
"This took me 4 seconds to Google: _URL_0_",
"It is much easier to apply additional energy to a system than to remove energy from a system. It's very difficult to systematically take energy away from vibrating atoms, whereas it's relatively quite simple to increase that energy.\n\nExample: It's very easy to input energy into the air by making loud sounds and noises that create pressure waves. It's much more difficult to stop those waves once they are in motion. All you can really hope to do is let them disperse at their own rate.",
"You mean a blast chiller? Have you never watched chopped",
"Here's what I do to chill beer quickly. It doesn't take a minute but it works way faster than just putting it in the freezer or a cooler with ice. You soak a paper towel and wrap the bottle in it. Throw it in the freezer and in 10 minutes you got an ice cold beer. I've been using this trick for years. ",
"On the molecular scale, when things are hot there are molecules whizzing everywhere, but when it's cold, the molecules are pretty well ordered. How quickly can you make a mess compared to cleaning up?\n\nIn practice, it's not actually that hard to make devices that cool things quickly, but it can be energy intensive or require relatively large equipment. (When things get bigger - like a roast turkey - it also gets harder to warm them up quickly.)",
"Refrigeration guy here! \n\nAs said earlier it is easier to add energy than it is to take away.\n\nWITH THAT BEING SAID!\n\nWe/They have what are called blast chillers also already noted in the comments. The ones in the 'Chopped series' are a common small scale type using ice. \n\nWe commonly size large scale blast chillers for places that cook hot food and need to quickly brought down to desired temp. Think cooking hot beans then to be frozen and shipped. \n\nNow you wont get anywhere near 60-90 seconds. But we can bring hot food 200*F+ Down to below 32*F in about 10-20min depending on plenty of variables! Pretty cool! ",
"dip in liquid nitrogen. Bam.",
"already exists\n\n_URL_0_",
"Perhaps [this](_URL_0_) is the product you're looking for - the spin chill, chills beers in 1 minute!",
"Co2 tank or co2 fire extinguisher point and shoot at beer.",
"Fire extinguisher will do it.",
"Reverse microwaves are being made but they are absurdly expensive. They use them on *Chopped* occasionally. Also anti-griddles.",
"It's like the difference between shooting a gun at someone's head vs. launching a bullet out of your skull. The energy we need to do stuff is in the gun (microwave), not the person (food item).",
"Mythbusters did it.",
"We actually do. I can't remember the official names for them, but we had a few in my culinary school (Johnson & Wales, North Miami) in our stocks and sauces kitchen. We always called them \"blast freezers\", IIRC. We used them to cool off large batches of stocks quickly (health codes require they reach a certain temperature in a certain amount of time, which can be tricky if you have 50 gallons of something). \n\nEdit: Turns out my memory was better than I thought! They are, indeed called [blast chillers](_URL_0_), and can bring large batches of food down to temp very quickly (this advertises from 135-41 in 90 minutes, which is actually insanely fast). Of course, it's not exactly practical for home use, with it's [$24,392.12 price tag](_URL_1_)",
"LG makes a fridge with a blast chiller in it. Closest to an actual product intended for the masses. _URL_0_",
"Any material has a property called 'thermal conductivity'. Basically, this is a measure of hot fast heat 'travels' through something. If you poke a copper pipe into a fire, the end you are holding gets very hot very quickly; copper has a high thermal conductivity. If you poke a wooden broomstick into the same fire, the end you are holding will barely warm up at all; wood has a low thermal conductivity.\n\nThe thicker something is and the lower thermal conductivity it has, the harder it is to get heat into its center. This is why a big beef roast takes hours to cook but a thin steak takes only a minute. \n\nSo this all limits how quickly you can put heat into an object or take it out of an object to change its temperature.\n\nA microwave oven gets around this by using microwaves, which can partially pass straight through things. This lets the waves reach the center of the food and directly heat it up as opposed to a normal oven where the heat has to slowly work its way in from the surface. This is why food in a microwave is generally hotter in the center when you pull it out.\n\nUnfortunately, there is no simple way to do a similar process in reverse to cool things down quickly. Things generally tend towards disorder and random motion in nature; disorder means heat. See the second law of thermodynamics.\n\nThe closest thing is special coolers for liquid which pump the liquid through a very thin, cold, tube. Since the liquid is very thin, its thermal conductivity does not really matter (think of cooking the thin steak) and it can be cooled much quicker than simply putting a glass into the freezer. This is how most drinking fountains cool down water quickly on demand. ",
"We do. It's called a bucket with ice water and lots of salt. Literally about 2-3 minutes and it's nice and cold. Don't forget to rinse the beer off first our your first couple of sips will be salty.",
"Brandon Dicamillo is working on this. Haggard. ",
"You must be talking about the Reverse Microwave!!!\n\n_URL_0_",
"They have liquid nitrogen \"grills\" that will freeze your food.",
"One important thing to remember is that it's always a transfer of **heat**.\n\nSince you're never transferring \"cold\", it's always going to be an issue of trying to transfer heat from the thing you want chilled. Because of this, you're limited by normal rules of heat transfer.\n\nYou could speed things up by increasing surface area of the thing you want chilled. It would also be beneficial to ensure the thing is \"circulating\" contact with the substance absorbing heat, as well as circulating the substance absorbing heat. You want to balance it so that you have continuous contact between the parts with more remaining heat and the substance with less absorbed heat.\n\nThis works best with liquids. They are easier to spread out into a wider surface area. They can even be pumped through the heat absorbing substance. If you want to chill something like... a whole cow, you'd need/want the heat absorbing substance to be pumped through the inner parts as well. Otherwise, you're limited by how the whole cow could transfer heat from inside out, as you cool the rest of it.",
"Ice cream salt in an ice-water bath works wonders for warm beers",
"Gonna get buried, but here we go.\n\nWe do, if you want to use the beer example. There was a Kickstarter a couple months ago for a lid you would attach to the top of your aluminum can or glass bottle (up to the size of a wine bottle iirc) and you would put the other end in your power drill, set the drink in a case of ice and spin the drill, chilling your drink in ~60 seconds. Legit worked.",
"Not sure if somebody has mentioned it yet but Laser-Cooling is pretty neat. I don't know how long it takes to get something to 0 degrees Celsius but if you give it a bit you can get pretty close to 0 Kelvin. Both use electromagnetic waves!",
"I need more freon for my reverse microwave!",
"We do. They're just not super popular... yet.\n\n_URL_0_",
"I used to work in a liquor store. Such things exist. They had this vat of cold water that when you put your wine or beer in, it cooled it rapido",
"There are also mug frosters that use co2",
"These machines actually exist in a way. My last job was at a factory that makes ice cream. When the ice cream is put into the containers, its obviously not fully frozen like it is when you buy it. The lab had to have some sample pints frozen before the batch was finished to run some test on them so they put them in a freezer machine that used liquid nitrogen to freeze it solid really quick. ",
"Put whatever you want to chill into a large container. Put in a bunch of ice. Pour in a couple of cups of salt. Pour in water until it's full. Rotate the bottle or cans every once on a while. It should be completely chilled after a few minutes.",
"Put water, ice, and salt in a bowl. Then put your drink in it. That chills it down to fridge temp in like three minutes. ",
"it's a lot easier to make waves in a calm pond than it is to calm a pond full of waves.\n\nMicrowaving food is like throwing a rock into a perfectly calm pond. Whereas, cooling something is like trying calming a turbulent pond. In this anaology, throwing a rock is like the micowave adding energy to the food. When food (or whatever) is hot, the best way to cool it is to calm everything around it (like a freezer).\n\nEdit: thanks for the gold!",
"That's not how it works! That's not how any of this works!",
"A peltier module can do this could it not? ",
"It's called a blast chiller.. They exist..",
"These answers are all fucking terrible! Here is the *actual* answer:\n\nThere are three ways to transfer heat: conduction, convection, and radiation. You might remember that from middle school science class.\n\nConduction means that if something cold touches something hot, the hot thing gets cold, and the cold thing gets hot. This takes an amount of time proportional to the temperature difference, so you want something very very cold or very very hot.\n\nConvection happens when a fluid has circulation. In addition to conduction, here the molecules are moving around, constantly circulating the energy difference. Your freezer works by convection, for example. Once again, the temperature difference affects how long it takes to heat or cool.\n\nFinally, there is radiation. All matter radiates energy according to its [black-body spectrum](_URL_0_). Radiating energy results in heat loss, but it is very slow. Radiation can also be absorbed, making objects hotter.\n\nYour microwave works by converting electrical energy into radiation, which is then absorbed by the object inside. The microwave is *actively* heating the food -- using large amounts of energy to heat it. But your food can only *passively* radiate energy according to its black-body spectrum, which is quite slow. Radiation just doesn't work in reverse like that. So now the only two options are convection and conduction, using freezers or something like liquid nitrogen, both of which do not work the same way as a microwave.",
"Salt water and Ice in a Cooler. Cold in five mins. (Source: Mythbusters _URL_0_)",
"Basically, it comes down to entropy and the laws of thermodynamics. The Universe has a built-in physical bias that makes it easy to add heat to stuff (by converting other forms of energy into heat), but hard to get rid of heat once it's there.\n\nRefrigerators (and freezers, and air conditioners, and so on) do not cool down the Universe overall, in fact they heat it up. They just cool down a certain region by applying a mechanism that concentrates heat (creating a bit more heat in the process) and releases it in a different place. But they work by using gas laws, and since you can't just compress some beer the way you can with air, what the refrigerator has to do is surround the beer with cold air and wait while the heat in the beer leaks out into the colder air around it.\n\nIt might be possible using nanotechnology to basically create a whole lot of microscopic mobile fridges can fly in and out of beer removing heat from it and cooling it as rapidly as a microwave oven could warm it. But we are still quite a ways from having that sort of capability.",
"It's worth noting that microwaves heat things by vibrating the water molecules in them and adding kinetic energy, whereas most coolers cool things by circulating cold air over them, which is much less efficient.",
"Liquid nitrogen. Frozen everything in 15 seconds. Bring your own container, that's where they rip you off.",
"We do. They're called wine chillers. Mine cools cans in about 60 seconds.",
"You can buy dry ice. A drop in your beer=instant cold. Few friends of mine in Australia do this. ",
"Mythbusters had this: Icebox filled with ice, water and bit of salt. Faster cooling then in fridge alone.",
"\n\n[Haggard](_URL_0_) Reverse Microwave",
"there's tech for something like that, using sound waves. you reverberate ultra low frequencies. temperature is the excitement and collisions of molecules. microwaves have a short wavelength that excites molecules and ultra low sound waves have long wavelengths that depress molecules, so they're less likely to have collisions or at least that's my understanding. the refrigerator I saw did this in an air chamber that then passes the cool air around your food. eh, it's kinda just a regular fridge, just without freon. the one I saw on the military channel that did the same thing was used for treating hypothermia or heat stroke. you would put your arm in and it would pass waves through your arm, cooling you down or heating you up instantly. so to answer your question; it's because the military loves to hoard technology.\n\n\n ",
"You see, it's all relative here. Just microwave yourself and the drink will seem cool in comparison. \n\nI'm a professional engineer. Trust me. ",
"While we're on the subject why is it that we have washers and dryers but no folders?",
"Its much easier to make a chaos than to add order to a system.",
"Take a can of soda, and shake it up - properly pump that elbow. If you pop that ringpull the soda is going to explode everywhere because of the fizz.\n\nOk, now unshake it. Yeah, you heard me. Unshake it. Get all the energy back out. Quickly now, I don't want to get soda all over me when I open that can.\n\nMicrowaves operate on the same principle. They shake up the water inside a food so much that it heats up and cooks the food. You're asking for something that could unshake the water, thereby removing its energy and cooling it down. Energy transferal doesn't work that way.",
"Presenting the [ChillCan!](_URL_0_) One of my friends is doing a PhD based around this product. It's a pretty cool idea. It achieves a temperature reduction of 10-15 degrees C below starting temp, using compressed CO2 which is released when the button is pressed. It is based on a much older idea, but unlike previous versions it doesn't require the use of CFCs in order to operate!\n\nDetails:\n\nThe ChillCan contains a cylindrical chamber of high-pressure CO2 gas, which ends in a valve that extends through the base of the can and is capped by a button. When the user pushes the button, the valve opens and the CO2 rushes out of the bottom of the can and into the air. As the gas expands, it absorbs heat from the surrounding liquid, lowering the temperature. ",
"Professional kitchens use something called a blast chiller, or a blast freezer. \n\nIt's not quite what you're referring to, nothing like it at all in fact but looks like a fun gadget to have...",
"Because heat is chaotic, in a sense. Random movements of atoms constitute heat, and adding more chaotic movement will generate heat (such as firing microwaves that excite some of the atoms, or placing it in contact with something with already excited atoms, ie. something hot).\nNot so with cold. Cold is the opposite, when atoms are moving slower. You cannot fire a beam or other energy at something, and make its atoms move slower. Or you can, but then you have to hit the atom from the direction it is travelling to - which is infinitely harder than just \"add energy by firing energy into something\".\n\nTL;DR: There is no cold, only less heat. You have to make the heat disappear in order to cool something - and there is no way to make eg. a beer suddenly give off more heat than by giving it a medium to do it to (something cold).\n\nYour best bet would be, I think, taking advantage of the chill factor. Move a lot of a colder medium close by the thing to be cooled, quickly. \n\nPS: Not a scientist, the wording here is not correct, but I believe the principles described are.",
"For the same reason you can't run a lamp in reverse to make it dark.",
"We have 'blast coolers' where I work that provide this function on a larger scale. Because of food safety concerns, food either has to be kept very hot (above 141 degrees) or chilled (below 41F) to prevent bacteria from growing. So, food that is cooked but meant to be sold cold gets put in a blast cooler that brings the temperature down within a couple of minutes. I don't know the specifics, but I imagine it is very costly and consumes a lot of energy to operate.\n\nThere are table top systems that are essentially the opposite of an electric stove top that draw heat out quickly from one surface. In theory you could get a big styrofoam cooler and fit a couple of those plates in, but it may not be efficient enough.",
"Maybe /r/askscience might be better if you're looking for a scientific answer.",
"Not enough fuckin freons",
"Mythbusters found the fastest way to chill beer is ice/salt/water in a cooler. 4/5 min freezing cold beer. Faster than any of their devices.",
"they have chillers like this in beer and wine stores sometimes (but they take a few minutes, not a few seconds), but the best you can do DIY is putting your beer in a cooler of water, ice cubes, and salt",
"Entropy. Heating something moves energy from a high energy source to a body in a state of low energy, until the two are at the same temperature. The machine you are describing would move energy from something cold into something warmer. This is like expecting all of the balls in the ball pit to stack up against one wall.",
"Heating is like adding sugar to tea or coffee. You have the thing, and you add another thing. You can add sugar but putting more sugar in. You can add heat by putting more heat in. It is very difficult, however, to take the sugar OUT of the mix. In fact, the only easy way to do it would be to add more unsweetened tea or coffee. \n\nSame with heat. It is easy to add more heat to your mixture, but it is hard to get heat out. The only easy way of getting heat out, is to add in some unheated and let them mix and dilute. If you want to make something cold quickly, the only way would be to find something even colder and let them mix. This is how a fridge or freezer work, except that air doesn't hold as much heat as a liquid, so the mix happens slowly. Adding your thing to be chilled to a a bucket of ice water will make it happen sooner. ",
"The way the microwave works is by agitating water molecules. Water molecules are polar (like little magnets) and if you change a field from up to down to up to down really fast you make them move a lot .... which is how you heat up stuff in the microwave. \n\nTo cool things down you would need to \"calm\" the molecules a lot and align them to allow them to create \"loose\" bonds (like they are in ice). So all we need is an electro-magnetic system that will align and calm down the molecules relatively fast. \n\nTo do so I thought of maybe using a very strong stable field. Like an ...MRI machine, but maybe stronger. Not sure if it would work or not. ",
"The reverse microwave:\nIs makes thing like really cold really fast. \nLike if your pizza is to hot and you don't want to burn the top of your mouth",
"Microwaves are radio waves. Like the waves on the sea that pound the shore, they work by slamming into your food and beating the shit out of its constituent molecules, speeding them up (which is the same thing as heat). There is no such thing as a *negative* wave that could *remove* heat. Electromagnetic waves contain energy and they can slam into things and donate their energy to the stuff they slam in to. No such thing as the opposite. Any attempt to cool something will rely on thermodynamic methods like convection (blast chiller) or conduction (freezer). These methods don't produce cold, they remove heat from food and move it somewhere else (back of your freezer). ",
"The process of removing heat doesn't work like that your not essentially freezing food your lowering the temperature of the space by removing heat that's what freezes the food. Heat travels from a warm object to a cooler one, the refrigerant is that medium. The process of the a refrigerator, freezer, a/c etc is to move the heat to a different area.",
"They do. In Hammond Louisiana at the Red, White, and Brew there is a chilling thingamabobber. There is a round hole on top, inside there is swirling freezing cold water. You take one to three warm beers off the shelf and place them in the water. Above the device is a sign that says 1 minute for chilled, up to 3 minutes for ice cold. So yeah go beer!",
"Kinda like how its much easier to push a car to get it moving than it is to slow a car down by standing in front of it. \n\nIts easier to go from low energy to high energy... its harder to take away energy like that. \n",
"This doesn't answer the question but I think it's relevant, if you want to chill a drink down wrap the can/bottle in a damp paper towel then place in the freezer. 5-10 min later it should be pretty cold! ",
"We do already! It's called my ex-wife, That bitch is COLD!!!!!",
"Doesn't ice water and salt chill a drink in like 2 minutes?",
"Theoretically, would it be possible to make something that tries to restrict/slow the movement of the molecules? If hitting them with a burst of microwaves makes em 'jiggle', could you hit it from multiple angles to keep them suspended in one place? Sort of like Acoustic Suspension?Levitation?",
"Haggard: the movie anyone ?",
"Someone did come up with something: _URL_0_"
]
} | [] | [] | [
[],
[
"http://www.amazon.com/Cooper-Cooler-Beverage-Chiller-Brushed-Silver/dp/B0000U3CIW"
],
[],
[],
[],
[],
[],
[],
[
"http://www.telegraph.co.uk/science/science-news/10404692/Reverse-microwave-can-chill-wine-bottles-and-fizzy-drink-cans-in-45-seconds.html"
],
[
"http://www.gizmag.com/spin-chill-kickstarter-drink-cooler/29382/"
],
[],
[],
[],
[],
[],
[
"http://www.traulsen.com/products/blast-chillers/",
"http://www.katom.com/206-TBC1332.html?CID=Shopzilla&utm_source=Shopzilla&utm_medium=CSE&utm_campaign=CSE&zmam=29342707&zmas=1&zmac=26&zmap=206-TBC1332"
],
[
"http://www.lg.com/us/refrigerators/lg-LFX31935ST-french-door-refrigerator"
],
[],
[],
[],
[
"http://youtu.be/haan3Tz0SJk"
],
[],
[],
[],
[],
[],
[],
[
"https://www.youtube.com/watch?v=JaGzz6RmbEQ"
],
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[],
[],
[],
[],
[],
[],
[],
[],
[
"http://en.wikipedia.org/wiki/Black-body_radiation"
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[
"http://kwc.org/mythbusters/2005/03/mythbusters_cooling_a_sixpack.html"
],
[],
[],
[],
[],
[],
[],
[
"https://www.youtube.com/watch?v=haan3Tz0SJk"
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"https://www.youtube.com/watch?v=j5FFcydaqKU"
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[],
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"http://www.dailymail.co.uk/sciencetech/article-2440094/Rapidcool-device-chills-drinks-45-secs-high-efficiency.html"
]
] |
|
6ccr7t | why can humans regrow things like skin and muscle but not organs like eyes and kidneys? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6ccr7t/eli5_why_can_humans_regrow_things_like_skin_and/ | {
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"I think you're confusing how skin and muscle *heal*, with *regrow*. \n\nYour organs heal on a daily basis from natural cell death and the toxins you ingest or are exposed to (such as alcohol), just like how your skin and muscle heal. But if you remove a muscle from the body, like if you removed a kidney, neither of them are going to regrow. \n\nYour skin doesn't regrow easily - scars don't count as regrowing. Scars are basically the body saying \"We can't regrow the original skin, use scar tissue to plug up the wound.\" like putting a poster over a hole in a wall.",
"So if the question is basically, *'why has our body not learnt how to regenerate major organs when damaged?'* remember that the only pressures on it having to do something like that, were part of natural selection as part of the food chain.\n\nAnd that selective process is dispassionate. It doesn't care for your overall well-being. It only matters that you, broadly speaking as an organism, can reach maturity and sexually reproduce. The things that work towards that goal would be well-developed. The things that didn't, not at all.\n\nThis is why your body replaces injuries with scar tissue instead of taking time and energy to restore the damage properly. This is why the loss of a digit has the body seal off the stump quickly and not invest the energy to regrow it. \n\nIt's basic damage control because doing it properly was not worth the investment of that organisms energy.\n\nRemember that through 99.999% of your ancestors history, food availability would have been patchy. Spending nutrients fixing a major organ would not have been sensible from a survival perspective. It only matters that you grow, breed, and then die off.",
"We can regrow a organ. The Liver. As long as you got a bit the rest will grow back. That's now transplants work. You slice a chunk of liver from a healthy person and shove it into the sick person. "
]
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||
46jemw | why hasn't the price of daraprim dropped since martin shkreli was arrested and resigned? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/46jemw/eli5_why_hasnt_the_price_of_daraprim_dropped/ | {
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"Because it turns out the problem was NEVER *one* rich greedy asshole. The whole system is fucked up.\n\nSee, for example [this.](_URL_0_)\n",
"The company has [offered](_URL_0_) a 50% discount to hospitals because insurers refused to pay. A compounding facility is [offering](_URL_1_) an alternative for $1. ",
"Because the whole thing is bullshit. The government refuses to regulate the industry, then when people take advantage of it, these dumb dicks all shake their head and act like the scam artist is the one who fucked up.\n\nIt's like leaving the keys in the ignition of your unlocked Maserati then getting mad that a bad guy stole it. Yeah the thief is a bad guy, but you didn't even do the simplest thing to stop them."
]
} | [] | [] | [
[
"http://qz.com/514553/massive-unexpected-drug-price-increases-are-happening-all-the-time/"
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"http://money.cnn.com/2015/11/25/news/companies/turing-pharmaceuticals-daraprim-price-drop/",
"http://www.fiercepharma.com/story/compounder-targets-turings-now-pricey-daraprim-1-pill-alternative/2015-10-22"
],
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||
4cr2jy | how do waiters and waitresses remember what dish goes to what table, when they are not numbered, in a large restaurant? | It has always blown my mind, maybe I'm just stupid or have a terrible memory. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4cr2jy/eli5_how_do_waiters_and_waitresses_remember_what/ | {
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"Tables typically are numbered in a restaurant, just the numbers are on charts the staff uses to refer to the tables and thus are not visible to customers. You sometimes may see your host or hostess with the chart when they are looking to see if there's an open table for you. The waiters and waitresses know the numbers of the tables they are in charge of and will write it down when taking your order.",
"Even if you can't see the tables, they're most probably numbered.\n\nNumbering is also crucial in defining sections for waitstaff as well. \n\nGenerally each restaurant will have a diagram that new employees have to learn. ",
"As noted, tables are numbered on a chart somewhere. Also, most waiters and waitresses are assigned specific sections for their shift; they aren't working with the entire restaurant at once.",
"One of the first thing you learn on a job are table numbers. The table itself may not have a place card on it, but there's usually a map of the dining room posted somewhere in the back or as part of the terminal the server uses to ring in orders.\n\nWhen a bill gets printed to the kitchen it will include the table number so whoever is running the food will also know where it goes."
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9upwhq | why do things, when deformed in any way (cutting, crushing etc.), make sounds? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9upwhq/eli5_why_do_things_when_deformed_in_any_way/ | {
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"Because sound is vibrating air, moving “stuff” also creates moving air, so when you cut an object it, along with the blade vibrate because the surface and object are not even, when crushing the folding and bending creates fast moving sections of the object and push out air that creates turbulence and therefore sound",
"When things bond together, they enter a lower energy state.\n\nTo make them break, you have to do work on them (push them, pull them, cut them, etc.). This temporarily increases their energy so that the bonds can break.\n\nNow that the bonds are broken, they have excess energy and settle back into a lower, unbonded energy condition. To settle, they release their excess energy, which comes in the form of sound waves.",
"When doing something like crushing a can different parts of the can suddenly twist and buckle causing the vibrations in the air that we perceive as sound. Even if it looks like things are deforming relatively smoothly, on a microscopic scale there are constant sudden random movements."
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||
9boc25 | why do some bank tellers have to stand behind a glass wall? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9boc25/eli5_why_do_some_bank_tellers_have_to_stand/ | {
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"Usually a rule implemented in high risk areas for security reasons\n\nSource: my wife is a banker"
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} | [] | [] | [
[]
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||
3y0h23 | how do search engines find and index websites? | We use a search engine to find a website, but how does the search engine find it?
In short, what is a search engine's search engine? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3y0h23/eli5_how_do_search_engines_find_and_index_websites/ | {
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"Search engines run applications - called bots, robots, crawlers, etc - that go out onto the internet and look at a particular page. They make a note of all the other pages that one links to, on the same site and on different sites, and mark those for visiting in the future. They extract all the relevant information they can out of the page they're looking at and add it to their index. Then they get the next page, and so on. Eventually they'll go back an have another look at a page to see if it's been changed since last time so they can keep things up to date.\n\nBig search engines are doing this on an industrial scale, I recall reading somewhere that google can re-index the entire internet in under a week, and are looking to get it down to under a day.\n\nHave a look at these pages for information about a couple of the more popular ones: [Googlebot](_URL_0_), [BingBot](_URL_1_)\n\nIt's also possible for website owners to submit their own sites to search engines, so that they'll be able to find out about it without having to 'discover' it organically.\n\nOne of the more interesting uses of this type of technology is the university assignment submission service called [TurnItIn](_URL_0_), they also use search engines and index the internet but rather than making it available as a search engine they use the data to detect plagiarised text in essays where a student has just lifted a sentence or more from a website verbatim.\n\nEdit: got better links for googlebot"
]
} | [] | [] | [
[
"http://turnitin.com/",
"https://en.wikipedia.org/wiki/Bingbot"
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|
25ntsi | how is pain and suffering calculated in lawsuits? | I was watching a court TV show and the plaintiff was suing for $7k for pain and suffering. After the judge, defendant, and plaintiff talked, the judge awarded $2000 in pain and suffering. How is pain and suffering calculated? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/25ntsi/eli5how_is_pain_and_suffering_calculated_in/ | {
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"Pain and suffering is purely subjective but it is calculated in loss. \n\n•Loss of physical safety. \n•Loss of mental safety...e.g. peace of mind. \n•Loss of potential. That is future limiting factors to the complainant brought about by the action of the defendant. ",
"\n\n\nThere is no hard and fast rule for how an insurance company must calculate pain and suffering. \n\nMany plaintiffs’ attorneys use something long the lines of the following: multiply the plaintiff's actual damages (medical bills and lost wages) by a certain number, generally between 1 and 5 (depending on the severity of the injury). For example, if a plaintiff incurs $3,000 in medical bills related to a broken arm, he might multiply that by three, and conclude that $9,000 represents a reasonable amount for pain and suffering.\n\n"
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8o1arm | what is it about enriching uranium that counties can't hide it from the rest of the world? | In movies villains have a way to secretly build nukes, but irl it always seems to be public information. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8o1arm/eli5_what_is_it_about_enriching_uranium_that/ | {
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"Enriching uranium requires you to take the rare U-235 out from the common U-238 and discard the rest.\n\nFirstly, you will need to purchase large amounts of uranium. This is pretty obvious to look for, everybody will know when large quantities are being shipped to/within your country. Unless your processing lab happens to sit on an undiscovered uranium mine you can’t access it.\n\nSecondly, you will generate a lot of radioactive waste (the common U-238). You need to dispose of it somewhere, preferably away from the population centres and where your processing lab is. This can be easily detected by satellites / random people with Geiger counters. The trucks used to transport the waste, personnel and equipment all need to be decontaminated which is near impossible to cover up.\n\nThirdly, you will need to hire nuclear Engineers. Oh suddenly all the nuclear Engineers in the country started working for the military/disappeared? Pretty big sign of a nuclear program. You also need very specialized centrifuges and chemicals which again can be easily tracked internationally.",
"Lots of extremely specialized equipment, industrial scale operations that are unique and a cuck ton of raw resources.\n\nThe size and scale makes it impossible to hide.\n\nIt would be like building the Hoover dam in secret. It just cant be done",
"Let me introduce you to [Oak Ridge, TN](_URL_0_). \n\nIn 1942 the US **built an entire city** just for the purpose of enriching Uranium for the Manhattan project. They used **60,000 acres** to build the necessary factories, and **70,000** people were housed in Oak Ridge to build and operate the factories. All told, this 3 year effort only produced enough enriched Uranium (about 100 lbs) for **ONE BOMB** (the other two bombs were plutonium based) by the end of the war.\n\nNow, I imagine that current technology has probably advanced this process somewhat, but it is still something that has to occur on a massive industrial scale. You can't hide construction like this from a spy satellite. And you can't hide purchases of some of the specialized materials needed to build the equipment. And you have to buy the raw materials from somewhere - raw Uranium is fairly rare and its purchase is carefully tracked.",
"First, you'll need quite a bit of uranium, likely more than your own country could mine in a few years time, unless you're in North America which has large reserves.\n\nNatural uranium contains only 0.72% of the isotope U-235, which is the one that can undergo fission, and the one that is useful for power reactors and weapons.\n\nExcept for microscopic traces of other isotopes, the rest is U-238 which is not directly useful in weapons or reactors\n\n(However U-238 can slowly be converted into plutonium by absorbing excess neutrons.)\n\nSo, to produce, say, 100 kg of material that is highly enriched in U-235, you would need a very minimum:\n\n100kg/.007 = 13,889 kg.\n\nIn reality you will need at least an order of magnitude more than this since the enrichment process is highly inefficient. Weapons grade material needs to be about 2/3 U-235.\n\nSo, importing dozens or hundreds of tons of uranium ore concentrates (\"yellocake\") is likely to raise a few eyebrows.\n\nThe second problem is that various enrichment processes require some pretty specific metals and materials. Enrichment involves converting the uranium into corrosive uranium hexafluoride, then vaporizing it into a gas. \n\nThe most common technique is the gas ultracentrifuge. This involves spinning the hot gas at a moderate vacuum, at incredibly high speed. The cylinders need to be fabricated and machined with the utmost precision and need to be perfectly balanced, otherwise they self destruct when spun up. It turns out that a special Cobalt-containing steel called \"maraging steel\" is the only material with the right combination of properties. So if you start trying to buy that stuff on the down-low, the International Atomic Energy Agency takes notice.\n\nEven still, the separation factor for one cylinder is low, so you need thousands of cylinders and hundreds of tons of metals and piping.\n\nSeal and gasket materials for process pipes and pumps also need to be made from rather specific materials to withstand the hot corrosive gas. You can't just buy the stuff from hardware stores.\n\nThen there's the fact that enrichment requires huge amounts of electricity. If you build a large power plant and transmission lines, buy a bunch of electrical switching equipment, but don't connect it to a known city or group of legit business, that's going to be pretty suspicious.",
"Enriching uranium requires doing very small amounts of activity on a very large scale. You're literally sorting atoms into \"heavy\" and \"slightly less heavy\" piles. Every machine you run the atoms through separates them by a tiny, tiny amount. So to change the overall percentage of \"slightly less heavy\" atoms (U-235) from less than 1% to 90% or so, and to do so in a reasonable amount of time (e.g., not a thousand years), you need a very large factory that takes a lot of electricity. \n\n\nThat size and electricity profile has made it possible to detect these factories from a distance — when you see a massive building that takes a massive amount of electricity and practically nothing is made by it, then you might ask what they're doing there, if you're already suspicious. Once you are suspicious there are other ways to verify it (e.g., taking a soil sample nearby, because trace amounts of uranium are often very detectable, just because of the large amounts of uranium gas that these plants handle).\n\nNow there is a historical caveat here. The early methods for doing this were _huge_. It's very hard to hide a gaseous diffusion plant, for example. [Here's the first one ever made](_URL_4_); here's a [more modern one](_URL_0_). Both are huge, but very efficient in terms of uranium enrichment.\n\nIf you're a clandestine nuclear power, you don't go in that direction. It's way too obvious and it's also pretty hard to pull off (the technology is difficult to get working and still highly classified). What you do is use a technology that was developed a bit later: the gas centrifuge. \n\nZippe-style gas centrifuges are not (usually) as efficient as gaseous diffusion. You still need a lot of them and their electricity profile is large. But they are physically much smaller and you can hide them in rather generic looking warehouses and even underground. And you don't have to commit to building them all at once — they can be built one-by-one. You still need a lot of them (e.g., a thousand or so) to start really enriching uranium in useful amounts for a weapon. But once you know how to build one, you can build another, and so on, until you have a lot of them. And the facilities are much lower profile. [Here's a Russian enrichment plant](_URL_3_), here's [an early centrifuge cascade in Iran](_URL_1_), and [here's the centrifuge building in North Korea that we didn't really know existed until they showed it to us, because it looks like a totally normal industrial building from the air](_URL_2_). Again, you still need a _lot_ to build a weapon, and it's still not super easy to pull off, but it's a lot easier to hide facilities like this, and much harder to tell what is going on.\n\nThe one other thing I'd note is that uranium enrichment requires very large amounts of uranium gas as uranium hexafluoride. This has literally no other use beyond enriching uranium, basically. So if you can track how a country moves uranium around, where it is producing this gas, where it moves that gas, etc., you're bound to see their enrichment activities. How hard is this? If you have no access to a country whatsoever (like North Korea), then very hard. If you do have access, through IAEA inspections or just spies, then the odds of these activities being spotted goes up."
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6cfc41 | when sad, we either eat too little or we eat too much; what decides our appetite to go one way or the other? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6cfc41/eli5_when_sad_we_either_eat_too_little_or_we_eat/ | {
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"I don't have an answer, but I've only ever felt this one way, being that I don't eat when I'm sad. I lose my appetite every time",
"Negative emotions decrease appetite **but** some people have learned that eating food makes them feel better so they turn to food when they're down."
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3h98dx | how come black coffee has a laxative effect while most other stimulants make people constipated? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3h98dx/eli5_how_come_black_coffee_has_a_laxative_effect/ | {
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"Which other stimulants cause constipation? Are you talking about rebound constipation?\n"
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9zasba | why don’t bones decompose? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9zasba/eli5_why_dont_bones_decompose/ | {
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"They do. What makes you think they don't?",
"Bones *do* decompose. They just do it slower than flesh. If you are referring to fossils, then fossils are NOT bones. Fossils are rock. A fossil is created when the bone is *replaced* by minerals slowly over a long long period of time. The end result after all the bone has decayed, is a rock copy of the bone."
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9uee8r | when driving, is there a speed that is the most fuel efficient? if so, what is it and why? | For the sake of simplicity, assume one is driving at a constant speed on flat ground. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9uee8r/eli5_when_driving_is_there_a_speed_that_is_the/ | {
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"I believe I read a while back that it was in your car’s highest gear, at the lowest possible rpm, which was usually around 55 mph but could vary.",
"Yup it's typically 50 to 55 mph, although most cars nowadays try to have as much fuel efficiency as possible when you're driving on cruise-control.",
"I see a lot of answers focusing on rpm, but we should also remember that this is something of an oversimplification that isn't overtly considering wind resistance (yes, they're related, I know). Most cars will hit the best mix of speed, reasonable wind resistance, and mpg at around 50-55mph, simply because it's \"fast enough\" for reasonable travel, but not so fast that you're wasting gas pushing through air. On average (depending on car and gearing) you're looking at a 20% decrease in mpg going from 55mph to 70mph. ",
"Yes, there is. It's called the \"cruising speed\", and it varies between engine designs (i.e. Ford's ecocharger* 6 cylinder engine can have a different cruising speed than Ferrari's turboguzzler* 6 cylinder engine). It's the optimal balance between speed and fuel consumption. \n\nJets, ships, helicopters, etc. all also have a cruising speed. ",
"In Pat Frank's novel, *Alas, Babylon* (1959), about a group of people surviving a nuclear war in rural 1950's Florida, there's an entire chapter about using a store-supply truck as bait to lure out some bandits who are raiding people. The book makes a point to explain that 35 mph, for cars back then, was the optimal speed for fuel efficiency. \n\nWith modern cars, according to the US Department of Energy:\n\"While each vehicle reaches its optimal fuel economy at a different speed (or range of speeds), gas mileage usually decreases rapidly at speeds above 50 mph.\n\nYou can assume that each 5 mph you drive over 50 mph is like paying an additional $0.20 per gallon for gas.4\n\nObserving the speed limit is also safer.\"\n\n_URL_0_",
"Because of wind resistance and rolling resistance, moving a car faster always requires more energy than moving it slower, so you might assume it's always more fuel efficient to drive slower than faster.\n\nHowever this isn't true for two reasons. You have a set amount of constant energy use to power the heater, the lights, the stereo, etc. The faster you go, the less time you are using this power.\n\nGasoline engines are inefficient at low power. Air and gas need to be mixed at a 14.7:1 ratio to burn correctly. So at low power if injecting just a small amount of gas, the air coming into the engine needs to be restricted. The engine needs to work harder to suck air in around this restriction. So the engine is wasting energy pumping air. (This is also how engine braking works)\n\nSo by going faster, you are creating more usable power out, with less energy in.\n\nThis does not apply to electric and hybrid vehicles which are much more efficient driving slowly, since they waste a lot less energy. A Tesla will be most efficient around 15 mph. ",
"The long and short of it is to go at the slowest speed in the highest gear that your engine can manage without labouring the engine. \n\nOn flat ground with most petrol engines this will be about 1500rpm. There will be comments that 1500rpm is too low but remember we are doing probably about 40mph on the flat so the load on the engine is really very slight (less than 20hp). On larger engines the revs can drop even further",
"You are balancing fuel usage for multiple things, internal frictions, rolling resistance, air resistance, baseline usage (electrical, etc.). The result is that there is a curve that peaks at a certain point, usually between 35 and 55 mpg. Here is a picture of such a curve, for two vehicles: [_URL_0_](_URL_0_) \n\n & #x200B;\n\n & #x200B;",
"At 0 MPH, your getting 0MPG, at 2500 MPH, your car would be glowing red hot from the friction. \n\n\nThere must be an optimum some where in the middle",
"[a glorious test](_URL_0_) was done by another redditor explaining this",
"All variables being equal between vehicles, each one will have a different RPM at which they're most efficient. The major factor at play is engine timing. Notice I said RPM instead of speed, I'll come back to that later. For now, lets start with an analogy. Think of a [speed bag](_URL_0_), like for training boxers. It starts out at low speed, it will require the entirety of the force of your punch to get it moving. As it speeds up and bounces back and forth, it requires less force to keep it going at a given speed, this is analogous to the engines RPM. Your cars engine works the same way. When you get the engine to the right RPM, it requires less fuel to keep it there. Lets say you start hitting the bag harder to get it spinning up faster. That requires more energy and will wear you out quickly. Letting the bag slow down will require more force to bounce the bag in a complete cycle. There's a sweet spot where the bag will complete bounces with minimal input. \n\n & #x200B;\n\nNow lets talk about timing. I've been assuming that your punches to this point have been continuously efficient, meaning that you hit the bag at the exact right time to increase its speed. Lets pretend you can only swing your hands at 4 different speeds. The slowest speed hits the bag as its just rebounding toward you. It requires a lot of force, but gets the bag up to speed faster. The next pace your hands can move at trades force for rate of speed increase, until you get to the top, where your hand is just tapping the bag as its swinging away from you. You can think of these hand-speeds as how much fuel your car is using and the point at which the fuel is being ignited. \n\n & #x200B;\n\nCoupling the most efficient timing and fuel delivery with the highest gear ratio will give you the speed at which your vehicle is most efficient.",
"_URL_0_\n\nIt depends on the vehicle and where it's power band is designed to be. In the 70's, when the US had a national speed limit of 55mph and subsequently in the late 80's that raised limits to 65mph and relaxed enforcement, drives manufacturer's to have the power band in that range as it let's them have higher efficiency ratings.\n\n",
"This question can be broken down into two parts. \n\n1) How much power is needed to push the car at different speeds.\n\n2) How much power the engine supplies at different RPMs and gears.\n\nAs for the power required to push the car, if we assume that wind resistance is the only force acting to slow down the car then you want to drive as slowly as possible. Doubling the speed will require four times as much power, so obviously the slower the better the efficiency.\n\nOn the engine side, the engine will suck up fuel at idle, because of this, if you go really slowly, the majority of your fuel will be used just to idle the engine and not to pushing the car forward. So you want to minimize how much power goes into turning the engine's moving parts (as it is wasted energy) yet keep the car at a slow speed to minimize air resistance. Going into the top gear means the engine needs push the car further for every time the engine turns over. This means more of the power from the engine goes into propulsion and less is wasted.\n\nIn an electric car, assuming that you don't have any overhead power draw (music, lights) you would be most efficient going very very slowly, but in a combustion engine car, keep to the top gear at a low engine RPM.",
"Not too sure if it’s a placebo effect or what. But I’m getting the best Mileage keeping my car under 250rpms up to fifth gear. \n\nEDIT; 2500Rpms",
"Look up hypermiling in EVs, especially Tesla’s. The most efficient speed is around 22mph. Has to do with drag and motor efficiency \n\nedit:\n\n_URL_0_",
"Air resistance to a moving vehicle is proportional to the square of the speed. Double your speed and you quadruple the power you need to move. Of course, you're covering twice as much distance, so the energy penalty is only 2:1 instead of 4:1, but it's still significant.\n\n(Now there are other factors that come in to play like the amount of energy it takes to simply keep the motor turning, or to provide heat or air conditioning in the cabin. Those factors can be *improved* by going faster.)\n\nBut at higher speeds, the air resistance dominates. After that it's essentially a nearly straight line on the speed-vs-fuel-consumption graph.\n\nThere might be certain RPMs that are more efficient than others for your given engine, which would cause a certain amount of waviness on the speed-vs-fuel-consumption curve, and there *might* conceivably be some actual dips in the curve, but for the most part, faster = more fuel consumption.\n\nA lot of people will *claim* that their pet vehicle is actually more fuel efficient at higher speeds, but these are mostly people who chafe at the 55 or 65 mpg speed limits.\n\nI would need to see some real scientific tests before I believe a truck running at 74mph gets better mileage than at 65 or 55 mph.\n\n----\nFinally, if you determine that say 2500 rpm is *much* more efficient than any other speed, then 2500 in second gear is still going to get much better mileage than 2500 rpm in 5th gear.",
"Depends on the car entirely. Every car has a sweet spot, a place where, for the gearing, engine stays at lowest possible revs, but without choking up (at which point consumption goes up considerably). \n\nEssentially, 6th gear, roughly 1300-1500rpm. Whatever the speed comes up to, that's about the sweet spot, give or take a few kms.",
"Mechanical engineer here, there's a lot of confusion going around this subject. and testing something yourself is almost useless, unless you can strictly control all variables which is close to impossible.\n\n & #x200B;\n\nthere are 2 things that have a major impact on your fuel efficiency,\n\n & #x200B;\n\n1: Wind drag and other losses, assuming you'll be going faster then grandma picking up the kids at school, wind drag becomes the dominant factor. ( [_URL_1_](_URL_1_) ) . so for all cases, the lower the speed the more fuel efficient with regards to drag and frictional loses. (not very useful info here) \n\n & #x200B;\n\n2: Engine efficiency, this is a big one that almost everybody gets wrong. The main thing here is called BSFC (Brake specific fuel consumption), this is the amount of fuel required to produce 1 hp (amount of fuel per hp). the lower the number, the more efficient your running the engine. and this says that an engine at its maximum load will be the most efficient, at an rpm range of 1/3 to 2/3 its max rpm. this is for a normal engine (not turbo or supercharger) , for those its actually better to be at \\~125% engine load (above 100% is only possible with a turbo or supercharger) .\n\nthey way to identify this load % is easiest achieved with a vacuum or vacuum/boost gauge. 0 vacuum = 100% load.\n\n( [_URL_0_](_URL_0_) )\n\ni have a 1.8t (1.8L turbo), i found almost a 50% increase in fuel efficiency by trying to hit 0 vacuum all the time while staying between 2500-3500 RPM. it requires you to think ahead a lot and occasionally speed.\n\n & #x200B;\n\nI hope this helps some people with this very confusing subject.",
"This depends on a lot of factors including engine size, camshaft profile, transmission gear ratios, and axle gear ratios. It’s different for each car. Generally it’s when your car is around 1700-2100 rpm in the highest gear. This happens to be around 55-65 mph. ",
"Yes. Generally, it'll be the middle RPM range for your highest gear. This is the main reason we have transmissions in the first place. Gasoline engines have the highest torque to fuel ratio in a tight RPM range. To be able to keep the car close to that RPM range at any speed, we have different gears you can switch between. I used to own an inboard boat, and they only have one gear generally. You learn to watch your tachometer and run it usually 3k-4k RPM for max fuel efficiency. Actual speed will depend on conditions, car, engine, etc...\n\nElectric cars incidentally have the same torque to energy ratio at any RPM. This is why they often dont have the need for a transmission. Highest energy economy in one would be quite slow as wind resistance would be your main enemy.",
"This kinda explains it.\n\n_URL_0_\n\nThe speed will be dependent on the engine and transmission of the car. People will say 55 or there about because that's the target that the manufacturer is trying to hit",
"I think it's not about speed but your engine's RPM, varies from engine to engine but I guess an average of 2000 - 2500 rpm is usually the spot for consumer cars",
"My car handbook says my most efficient speed is 80km/h. Check your handbook perhaps?",
"You've got a bazillion answers here. There's the ELI5:\n\nYes, there is a speed for every car that is the most fuel efficient.\n\nThen, there's the rest:\n\nIt's a sweet spot that is different for every car, but is a combination of:\n\n* Engine design - Every engine has a sweet spot, both in RPMs and in *temperature*, of both the engine and the incoming air. There's a certain engine speed that makes the most power for the least amount of throttle application. At this point, you're getting the most energy possible out of each measured explosion. \n* Transmission design & associated gear ratios. These are chosen to either give you good acceleration, good fuel mileage, or an attempt at both. Transmissions like the modern \"CVT\" can play games to give you both. \n* Wheel & tire design. Tread design, tire inflation, rubber compound. Tires will heat & soften at higher sustained speeds, increasing rolling resistance. Different tires have different behaviors with regard to increased speeds and ambient temperatures. \n* Aerodynamics. \n\n**Of this entire list, aerodynamics will be the most dominant. When you double your speed, you quadruple the wind resistance. It is the only parameter in this list that increases in this fashion.**",
"There is but for each car is different due to different gearing. \n\nSo to safe fuel you is to keep the engine rpm low with no power added. Depending on the gears and ratio on some it could be 50 others 40 and so on. This is what over drive is. It’s just not a standard thing since we have different sizes of vehicles and power ranges.\n\n",
"On hilly roads, cruise control eats up gas to make sure you maintain the set speed.\n\nI drove from Chicago to LA in 4 days. Over the first two days i used cruise control. The final two days i did not use cruise control, i just kept my foot slightly on the gas, going uphill slower and downhill faster. 4 MPG better without the cruise control.\n\nTLDR: dont use cruise control.",
"How much fuel you use is combination of how hard you press the accelerator, and how high your rpm is.\n\nIt changes for each car, as different wind resistance, engine torque, and friction of moving parts all impacts it. \n\nBut you don't need to know these things. In fact modern cars have a little meter to tell you \"mi/gal\" or \"km/L\" which is essentially measuring fuel useage. And you can watch it go way up when you accelerate hard, and drop when you back off.\n\nYou can use this to see \"what your most efficient speed is\" by getting on the highway and traveling at different speeds, and seeing which speed reads the lowest fuel consumption.\n\n\nEdit: to specifically answer \"is there a most efficient speed\" yes, there is. But it varies depending on the vehicle. \nFuel useage will always increase the faster you go, but there will be a point where \"the distance you cover vs the fuel used\" will reach a sweet spot.",
"Secondary question: Would there be a way to make a dashboard gauge that tells you when/where this equilibrium is acheived?",
"I drive a 2018 honda crv. Theres a circle around the speedometer that changes colour based on your acceleration or speed or whatever. Is the computer calculating that sweet spot in real time for my car (when its green its most fuel efficient)?",
"There's another very important reason that hasn't been brought up. Not only do the inherent thermodynamic/mechanical properties of an engine or car determine its most fuel efficient speed, but so does the EPA (in the USA, at least.) The EPA tends to test the fuel efficiency of cars at a specific speed, so often the manufacturers deliberately design the engine/car to be the most fuel efficient at that speed, typically ~55 mph.\n",
"I don’t know if it has already been said but basically what you want to do is look at your tachometer and stay below 2500 rpm even when accelerating. I do this and i get a lot of miles per tank (just a lil over whats advertised for the car. ",
"Eli5: it's not the speed but the revolutions of the engine. The lower the better. So try to reach your destination in time with the lowest possible to drive most efficient.",
"I think the simplest answer here for someone that doesn't want the math; an answer that is most universal and approximately true.\nThe slowest speed after the car shifted into the highest gear. In other words, if most automatics shift into last (overdrive) gear near 45-50mph. This is likely the best gas milage you'll get. ",
"I'm no professional, but I think in general, the most fuel efficient cruising speed will be at the lowest rpm you can get in the highest gear of your transmission. This should mean fewer explosions per mile. ",
"I have found my car gets better fuel mileage when going downhill. That's why I put taller tires on the rear so it's always going downhill.",
"None of these essays people are writing seem very eli5. The simple answer is every car has different gearing and tuning so there is no certain speed that is most efficient for every car. It's the same reason that 2 cars can put cruise control on a 70 and still gain or lose distance. The cars accelerate and decelerate at different speeds on hills and inclines because the cars have different gearing. "
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"https://en.m.wikipedia.org/wiki/Power_band"
],
[],
[],
[
"https://cleantechnica.com/2018/07/15/tesla-range-plotted-relative-to-speed-temperature-graphs/"
],
[],
[],
[
"https://www.researchgate.net/publication/316530475/figure/fig4/AS:495842618089478@1495229500689/BSFC-map-of-the-engine-7-BSFC-brake-specific-fuel-consumption-rpm-r-min-Max-maximum.png",
"https://www.withouthotair.com/cA/figure321.png"
],
[],
[],
[
"https://youtu.be/iNspNdVkslA"
],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
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] |
|
3ryy44 | why are there so many psychotic idiots in the youtube comment sections? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3ryy44/eli5_why_are_there_so_many_psychotic_idiots_in/ | {
"a_id": [
"cwsjsn9"
],
"score": [
2
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"text": [
"I think it has more to do with the large user base on Youtube and that anybody can comment on any video, without any criteria, given that they have an account.\n\nAlso, the anonymity allows trolls and internet bullies to come out and hide behind an internet wall where they can berate video makers with little consequence."
]
} | [] | [] | [
[]
] |
|
61tu4u | does data have mass? | If I have a backup tape, and fill it to capacity (say 6.25 TB in this case) does it weigh any more than it did when it was empty? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/61tu4u/eli5_does_data_have_mass/ | {
"a_id": [
"dfh7iyj",
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"text": [
"Data may use a medium that has mass, like a magnetic platter to be stored on.\n\nA hard disk full of data is no heavier than a hard drive with no data.\n\nData may be transmitted via a \"massless\" system, such as light.\n\nSo, I would say, no, data does not \"need to\" have mass, unless some physical substance is added to put the data into a readable or storable state.\n\nAlso, [this.](_URL_0_)",
"[**EDIT: CyberJerryJurgensen and MatheM_ are correct. Not all data has mass, but some does.]\n\nIt absolutely does! It will weigh more, but almost infinitesimally more. There is a great Vsauce video on this very topic: _URL_0_",
"Yes and no. No electronic storage medium will have an appreciable change in mass when \"full\" or \"empty.\" Magnetic storage media (HDDs and tapes) work by flipping magnetic domains on the media which does not change their mass at all. Other types of memory (RAM and SSDs) work by storing electrons in capacitors or floating gate transitors and because electrons *do* have a very small amount of mass writing one of these devices with all 1's would increase the mass ever so slightly. \n\nNow if you were to ask a physicist, particularly one who believes the holographic principle, then information absolutely has mass. If you were able to cram enough information into a small enough area you could reach an information density high enough to create a black hole.",
"You can think of data as a verbal language. A word does not have weight, it is an idea that is transmitted from one person to another via sound waves. It can also be transmitted through writing on a piece of papaer with, lets say, a pen. In both cases of using sound and paper as the medium, we can detect the word being presented by noticing a change in the matter around us. But that does not change the fact that the original word is an idea to begin in the first place.\n\nNow, if you want to get really nitpicky you could argue that a word cannot be created without the use of mass. Even as a thought, the word is transmitted through the brain via electrical and chemical pathways. But in the end all you've really done is say that there is potential in everything that has mass to carry data, not that the mass itself has been increased or decreased; the mass has been shifted.\n\nSo tl;dr\n\nTo answer your question fully, the only reason a hard drive would weigh more is if something were added to the hard drive in order to represent the data. Otherwise, the mass in your hard drive is simply being shifted around to represent your fluffy cat pictures.",
"It depends on how the encoding of the data is done. In your example of magnetic tape, data is just different assortment of bits (ones and zeros) on that tape. In that regard any combination of bits is data. Even all zeroes or all ones or gibberish. Now there are three options.\n\n* logical one can weigh tiny mini more than zero. In that case tape full of ones is heaviest.\n\n* logical zero can weigh tiny mini more than one. In that case tape full of zeros is heaviest.\n\n* they weigh the same. In that case the there is no diference between ones zeroes or gibberish.\n\nSo without knowing how exactly is the storage implemented it can be either of these options."
]
} | [] | [] | [
[
"https://www.reddit.com/r/askscience/comments/3nrr10/does_data_have_mass/"
],
[
"https://youtu.be/WaUzu-iksi8"
],
[],
[],
[]
] |
|
2vs5aj | why is it that sometimes when i browse a page the browser's "loading" circle at top does not stop even after a long time and when the page seems to have completely loaded | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2vs5aj/eli5why_is_it_that_sometimes_when_i_browse_a_page/ | {
"a_id": [
"cokiidf",
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"score": [
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30
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"text": [
"The most likely reason behind this is that there is javascript that is still being processed.\n\nA well-respected design practice is to put as much javascript/jquery code at the bottom (end) of your website, because a lot of the things you use javascript/jquery for take longer to process. Code is read from top to bottom, so all the basic text and html will get processed first by the browser, allowing it to display the core page elements, leaving the javascript for last. A lot of the actions javascript is used for are things that aren't immediately visible on the webpage, but allow for background functionality.\n\nAnother possibility is that the website host has successfully served up all of its page data, but the ad-servers haven't. Especially with ads that have audio and/or video that take longer to retrieve, and in the cases where the ad server is physically located further away than the host server.",
"Your browser considers page fully loaded when all the assets (styles, images, scripts etc) on the page are loaded. Some of those might be located on different servers or provided by third party on completely seperate network. When at least one of such resource is still loading, your browser will show the spinning circle.\n\nSometimes things break and server with single unimportant asset (like ad provider or facebook widget) might be unreachable. It can take up to a minute for your browser to realize that it is not going to get those files and give up. The browser can't tell if the thing it is trying to load is important or if it would matter to you at all - so to play it safe, it spins the circle to let you know there is more to come.\n\nThere are ways for web developers to load external assets asynchronously - that's why you won't see spinning circle on high-profile script-heavy pages like gmail, even when you clearly see the page is not fully loaded yet - but barely anyone minds or cares and it takes significantly less effort to do it \"the okay way\" than \"the better way\"."
]
} | [] | [] | [
[],
[]
] |
||
1uo99h | why does the xbox one need a brick in between the outlet plug and the console where as the ps4 doesn't? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1uo99h/eli5_why_does_the_xbox_one_need_a_brick_in/ | {
"a_id": [
"cek27rf",
"cek4fyj"
],
"score": [
7,
4
],
"text": [
"The PS4 has the power brick built into the console itself.\n\nThis choice is a design trade-off. If you have it inside the case, your case has to be bigger to make it fit, and has to have better airflow to account for the increased heat. On the other hand, having it on the outside means you can see it, and some people don't like that.",
"Power supplies do two things: \n\nThey convert electricity from the kind that comes out of the wall to the kind used inside the device. In most advanced economies, that's Alternating Current from the wall, and Direct Current inside the device(1).\n\nThey also \"condition\" the power, smoothing it out and removing variation and spikes. Most electronics work best (and can be damaged without) very \"clean\" electricity without much variation.\n\nThe problem is that the circuits we use to do the conversion and the conditioning generate heat and generate radio frequency radiation. Managing the heat inside the \"enclosure\" - the box - is a tradeoff of engineering; the hotter things run, the more fan power and cooling is needed to get that heat out of the enclosure to keep the temperature within the enclosure safe for the electronics. Radio frequencies can also interfere with the functioning of electronic components, and shielding the components from the radio frequencies being emitted by the power converter/conditioner add weight and complexity to the enclosure.\n\nMaking converter/conditioners that can work inside the enclosure is expensive, tricky engineering. Those parts fail more often than a lot of other things like the circuits of the motherboard or the optical drives, so having an external converter/conditioner makes replacement easier/cheaper too.\n\nEnd of the day, Microsoft's engineers and marketers decided that the best cost/benefit tradeoff for the XBone was an external converter/conditioner, and Sony's engineers and marketers decided the opposite.\n\n(1) Alternating current has properties that make it easier to transmit over long distances. Direct Current makes more logical sense when you operate a device - you usually don't want the current flow to change direction several times a second. Turns out converting from AC to DC is reasonably easy to do, which is why we have a hybrid electrical grid."
]
} | [] | [] | [
[],
[]
] |
||
4iguqv | why are people claiming that the silicon valley start up bubble is going to pop? | Lived here my whole life, always knew we were the life of technology. Once I started going to college in sf, I was introduced to the fact that start ups were a huge thing. Recently however, people are claiming that the start up bubble is going to crash. Why is this? And why does a dead unicorn symbolize it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4iguqv/eli5_why_are_people_claiming_that_the_silicon/ | {
"a_id": [
"d2xz7ae"
],
"score": [
2
],
"text": [
"One factor is that the computer science industry is not sustainable. When I was in school, I had a bunch of friends in computer science. On of them hadn't picked up CS until his freshman year of college, yet by his sophomore summer, he was getting summer internships that paid the equivalent of $50,000/year plus bonuses. He received a job offer out of undergrad for $100,000/year, but turned it down because he wanted to do something else with his degree. \n\nNow, he's very good at what he does. But that's a crazy return on investment compared to other industries. Lots of internships are unpaid, and most fields don't have nearly that kind of immediate payoff. But until very recently, having just a little bit of formal education in the subject made you an expert in a very valuable field. But as more people do computer science, and as more people do it longer, the pool of applicants will grow and landing that crazy awesome internship will be a LOT harder. And when these skills become more readily available, they won't be as valuable. Eventually, CS will become like most other industries--the top tier make awesome money, the middle tier are fine, and the lower tier struggle to get by."
]
} | [] | [] | [
[]
] |
|
110krh | what happens when you get into a car wreck with an on-duty police officer, and said officer is clearly at fault? | I've never actually heard of anyone getting into a wreck with a cop where the cop was at fault for the accident.
What happens in this process? Assume the on-duty cop is *NOT* responding to an emergency...he's just driving around. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/110krh/eli5_what_happens_when_you_get_into_a_car_wreck/ | {
"a_id": [
"c6i8e72"
],
"score": [
3
],
"text": [
"The cop would be subject to the same laws and insurance policies as anyone else. Additionally, they would probably be reprimanded by their supervisor or superior officer."
]
} | [] | [] | [
[]
] |
|
2oqbnq | why do i look at and think the shirt is yellow and white but my friends all clearly say it's dark blue and black? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2oqbnq/eli5_why_do_i_look_at_and_think_the_shirt_is/ | {
"a_id": [
"cmpiqi1",
"cmpj2bb",
"cmpj6uh",
"cmpjpng",
"cmpju9f"
],
"score": [
8,
3,
3,
3,
2
],
"text": [
"I see blue and black. You sir are colorblind. ",
"Tell your friends to not use shitty filters if they are discussing the colour of something. I'm colourblind but I see blue/black.",
"I can tell it's blue and black but there's a yellow wash in the image, possibly due to a filter. The black has a very yelliw tinge.",
"Huh. I've taken three forms of color blindness tests in the past few minutes, scored perfectly on all of them. That shirt looks yellow and white to me. I think it might be something to do with the computer display?",
"I see black and blue. OP send us a different picture of what you see as absolute black and blue. "
]
} | [] | [] | [
[],
[],
[],
[],
[]
] |
||
dztqip | how do vegas oddsmakers decide what the spread will be in football, and how do they seem to get it right most of the time? | Additionally how do they figure other odds like over/under etc? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/dztqip/eli5_how_do_vegas_oddsmakers_decide_what_the/ | {
"a_id": [
"f8a55q5",
"f8a7asb"
],
"score": [
9,
2
],
"text": [
"So we have to toss out one part of your question because its actually wrong, and it'll make it even more confusing for you!\n\n > and how do they seem to get it right most of the time?\n\nThey don't get it \"right\", and they aren't even trying to, thats not their goal.\n\nTheir goal with the line(s) is to put them in a position where they have about a 50/50 bet on each way of the bet. It's NOT to predict the actual score, its to find the perfect line that will get about half the bets one way, and half the bets the other way.",
"Honestly, for years, money has been on Velveeta or Philadelphia Cream Cheese, but recently (thanks to either Gen-X’ers, millennials or picky-eaters coming to terms with their limited pallets) Guacamole has nearly reigned supreme.\n\nNow I will agree, chili-cheese or some other cheese-enabled-concoction has been the front runner for decades as the official hometown football spread (or dip), running the market and maintaining its supremacy, but the folks in Vegas will agree that it is seeing a sharp (cheese pun) decline.\n\nAs is, this is solely based on market driven opportunities coupled with the ever growing implementations of how the American culture changes with growing appreciation for medical care and health advice. Vegas is currently seeing 3/5 for Guac, 2/5 for Cheese, and a humble 1/5 for plain Salsa, however there is a flex for a median of Spicy-Queso Blanco (which folks are using to hedge their bets) as a middle ground for those trying to work numbers."
]
} | [] | [] | [
[],
[]
] |
|
akw0eu | what is the difference between standard and itemized deductions? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/akw0eu/eli5_what_is_the_difference_between_standard_and/ | {
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"ef8dtj6",
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"text": [
"Standard deduction is a number declared by tax law to be an amount you're allowed to deduct I believe from gross income.\n\nItemized deductions is where instead of using that standard number, you tally up all expenses considered deductible (It's all specified in the law and most tax prep software will ask you all sorts of questions to help you get everything if you select itemized) and deduct them instead. There's actually quite a bit allowed in itemizing, but it is not worth going itemized unless your total is greater than the standard deduction.\n\nIf you will be going itemized, it is extremely important that you save all receipts related to the deductions in case you are audited.",
"At a certain point in a typical person's tax return, you have the option to reduce your taxable income by either:\n\n1. The Standard Deduction(a fixed amount based on you filing status), or\n\n2.The sum total of specific Itemized Deductions based upon you other financial data (e.g. total local and state taxes, mortgage interest, etc.)\n\nWhich ever one of the above gives you the highest amount, is the one you want to elect to reduce your taxable income. \n",
"Standard deduction is just Set amount anybody can claim without having to prove anything.\n\nItemized is when you add up all the various deductions you’re eligible for, and have proof to back them up. Things that can be deducted include mortgage interest, student loan interest, state and local taxes paid, certain medical expenses, charitable donation. You’d only utilize if your deductions would be greater than the standard deduction."
]
} | [] | [] | [
[],
[],
[]
] |
||
79a7wi | how can we discover planets that are so far away? | I always wondered how can we find those planets that are light years from Earth. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/79a7wi/eli5_how_can_we_discover_planets_that_are_so_far/ | {
"a_id": [
"dp0bpaw",
"dp0rups"
],
"score": [
18,
17
],
"text": [
"Usually exoplanets are discovered by looking for a characteristic wobble of stars in a telescope.\n\nBecause gravity from planets will affect the spin of their star, stars with planets will appear to wobble back and forth compared to other, naked stars.\n\nThen, by calculating the expected size of the star and the size and frequency of the wobble, they can make an educated guess as to the size and distance of the exoplanet from their star, or even if there are multiple exoplanets.",
"5 Ways to Find a Planet according to _URL_0_:\n\n1. WATCHING FOR WOBBLE; Radial Velocity; 654 planets discovered\n\n2. SEARCHING FOR SHADOWS; Transit; 2758 planets discovered\n\n3. TAKING PICTURES; Direct Imaging; 44 planets discovered\n\n4. LIGHT IN A GRAVITY LENS; Gravitational Microlensing; 51 planets discovered\n\n5. MINISCULE MOVEMENTS; Astrometry; 1 planet discovered\n\nYou can watch simple gif's and animated videos of each method here: _URL_1_"
]
} | [] | [] | [
[],
[
"Nasa.gov",
"https://exoplanets.nasa.gov/interactable/11/"
]
] |
|
1oxxzu | why can the senate keep trying to pass cispa, even though it keeps getting voted against? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1oxxzu/eli5_why_can_the_senate_keep_trying_to_pass_cispa/ | {
"a_id": [
"ccwqt04"
],
"score": [
2
],
"text": [
"They can keep proposing it as much as they want. Maybe votes will change, maybe it won't, but you can always propose a bill to vote on. \n\nFor reference, the house has voted (and passed) a repeal to The affordable care act something like 42 times. "
]
} | [] | [] | [
[]
] |
||
a1ut8y | how does the nintendo 3ds work? | How does the 3DS display 3D gameplay with just turning the switch on? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/a1ut8y/eli5_how_does_the_nintendo_3ds_work/ | {
"a_id": [
"eat4tmo",
"eataslv"
],
"score": [
20,
3
],
"text": [
"The screen is displaying two images at once, in alternating vertical columns. In front of the screen is a barrier that blocks half of the columns. When you're at the right distance away from the screen, the barrier blocks one image entirely for one eye, and the other for the other eye, creating a 3D effect. At the wrong distance, you get a garbled mess of both images. Turning the effect off just causes the entire screen to display the same image. The barrier is still there, but now it doesn't matter what angle you view it from, both eyes will see the same image.",
"Have you seen those rulers with bumpy surface, and they show you different pictures when you look at it from different angle? It's like those.\n\nThe 3DS screen is a made up of a bunch things like really small Triangular prism, they will direct 1 picture to your left eye, and another to your right eye.\n\nThe picture actually looks like this +-+-+-+-, there's a prism for each set of +- (or may be ++--++--, then each prism for each set of ++--, I hope you get the idea), so your left eye will see ++++ and your right eye will see ----. The important thing is how far apart the prisms sent each picture, which is adjustable\n\nedit: it may not be prism, but the idea is sending alternating slivers of picture to each of your eyes"
]
} | [] | [] | [
[],
[]
] |
|
3596kg | what would happen if we just threw all the nuclear weapons into a volcano? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3596kg/eli5what_would_happen_if_we_just_threw_all_the/ | {
"a_id": [
"cr27f2v"
],
"score": [
3
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"text": [
"Nothing at all. Nuclear weapons are not just really really big sticks of dynamite, they're complicated machines that need a very particular sequence of events to arm and detonate. They are *active explosives*, they will never explode unless you *really really* want them to. \n\nedit: The most important thing to realize is that the \"active ingredient\" in nuclear weapons, the thing that explodes, is elemental Uranium. It's just a block of metal. It's hard, it's shiny, and if you saw some in real life you would think it's iron or lead. It is not interesting at all until you compact it, heat it up, and then bombard it with ultra-high-velocity neutrons. "
]
} | [] | [] | [
[]
] |
||
8k0k7o | what happens to my plastic bottle after i throw it in the recycling bin? | How long does it take before it is another plastic object for consumer use? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8k0k7o/eli5_what_happens_to_my_plastic_bottle_after_i/ | {
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9,
30,
2
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"text": [
"To piggyback on this. I've always wondered if it all goes through some type of decontamination process of some sort....?",
"\" We've all been told that we should recycle plastic bottles and containers. But what actually happens to the plastic if we just throw it away? Emma Bryce traces the life cycles of three different plastic bottles, shedding light on the dangers these disposables present to our world \"\n\n[_URL_1_](_URL_0_)",
"I once met a guy whose dad made a fortune spinning bottles into thread (unsure of the method). The thread ended up in clothing like polar fleeces and such. This was a few years ago so market conditions may have changed.",
"TL;DR: Your plastic bottle will almost always wind up in a bale of sorted \"mixed plastic\" in a few days, maybe a week or so. But it's hard to say how long it will be until that bale is processed into recycled plastic granules/pellets and then used to make consumer goods. \n\nLet's start with you putting your plastic bottle in a recycling bin. What happens next?\n\nFirst, the bin gets collected by a waste management company. This may or may not be the same company that collects non-recyclable garbage in any given area, but it's almost always done with trucks dedicated to recycling. The recycling trucks dump their loads at a recovery facility that may or may not be owned by the same company that owns the trucks. These drop offs occur pretty much all day during business hours, but any given recycling bin is typically only collected once a week. \n\nSecond, the recovery facility sorts incoming \"mixed material\" into different categories using a number of different processes, some automated, some manual. Paper is sorted with an \"air knife\" that blows it onto a different belt while leaving heavier materials behind. Metals are separated with a magnet (yes, even aluminum, though not in the same way that steel cans are). Rotating drums sort out lighter materials (like plastic) from heavier ones (like glass). And \"pickers\" remove things like plastic bags, contaminated cardboard, wet/shredded paper, etc., that tend to jam up the machines. Your plastic bottle will most likely end up in a gigantic container containing almost all plastic, sometimes even sorted by plastic type (depends on the facility). The recovery facility will then compact these plastics (mixed or otherwise) into bales, usually of a size appropriate for moving around with a skid loader. This sorting/baling process can potentially run 24/7, depending on how many different waste management companies are dropping off \"mixed material\" at a particular recovery facility. \n\nSo, how long does all of the above take? Well, it could be anywhere from a few minutes to an entire week after you put your bottle in the bin before it gets picked up. But once that happens, it'll probably make its way into a sorted \"mixed plastics\" bale in less than 24 hours, as recovery facilities try to process material more-or-less as fast as it comes in. Otherwise they'd wind up with an ever-expanding amount of un-sorted material to store!\n\nRecovery facilities sell these bales to plastic recycling companies. Plastic recycling companies take in these bales, sort them (far more carefully than the recovery facility does, and sometimes dividing different kinds of plastic into different production lines), wash them (recovery facility doesn't do that), shred them, and then melt them down to be molded into granules/pellets suitable for use in manufacturing processes. \n\nHow long does it take for mixed plastic bales to get recycled? Hard to say. Recovered \"mixed plastic\" bales are an industrial commodity. Recovery facilities obviously like to move their inventory as fast as possible, but it could be anywhere from a few days to a few weeks before any particular bale gets sold, for any number of reasons not important here. Once a recycler buys a bale, it will typically process it almost right away. But then there's another indefinite period between producing the recycled plastic granules/pellets and selling those on to a manufacturer. Once a manufacturer buys recycled plastic, it's typically used to make consumer products almost right away. But those two delay periods--between compacting a bale and selling it, and between producing recycled plastic granules/pellets and selling those--make it hard to provide a precise estimate. Again, anywhere from a few days to a few weeks. A few *months* even, if the market in recycled plastic is slow for whatever reason. Shipping takes time too, so add in a day or two for each step. ",
"Well if you throw it away at your work it most likely gets combined with all the other trash and taken to the dump."
]
} | [] | [] | [
[],
[
"https://www.ted.com/talks/emma_bryce_what_really_happens_to_the_plastic_you_throw_away",
"https://www.ted.com/talks/emma\\_bryce\\_what\\_really\\_happens\\_to\\_the\\_plastic\\_you\\_throw\\_away"
],
[],
[],
[]
] |
|
8oulu1 | why math are so difficult? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8oulu1/eli5_why_math_are_so_difficult/ | {
"a_id": [
"e0689xd"
],
"score": [
2
],
"text": [
"This probably depends from person to person, but math can be very difficult because it's not really tangible and it's not something that we see in our every day lives. By contrast, something like English might be picked up much easier in the United states because we speak it every day and are constantly surrounded by it, so it \"makes more sense\" because we are used to it.\n\nAnother reason could actually have to do with how our brains work versus how numbers work. Our brains work with orders of magnitude (this is why it takes a 10× increase in amplitude to make something sound twice as loud) where as numbers are linear. Our brains have developed to better understand the difference between 10 lions and 100 lions, not 100 lions and 101 lions.\n\nSo there's probably a lot of factors and it probably varies between everyone, but I would say a lot of it lies in the fact that it's just not really occupying our minds for a large part of life, so it doesn't come as naturally."
]
} | [] | [] | [
[]
] |
||
3agbzz | why do i see red and blue dots and lines instead of darness. | When it's really dark, I see blue and red dots or lines. Is this normal in people? Why does it happen? Shouldn't we just see darkness? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3agbzz/eli5_why_do_i_see_red_and_blue_dots_and_lines/ | {
"a_id": [
"cscl5a0"
],
"score": [
6
],
"text": [
"I believe you're seeing the after effect of what you were looking at after saturating the cones in your eye."
]
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7cswnn | do fish in aquariums know they’re in aquariums? can they tell the difference? | Does it vary among different types of fish? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7cswnn/eli5_do_fish_in_aquariums_know_theyre_in/ | {
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"They are aware of their surroundings but since pet fish have never known freedom they have no perspective(assuming fish are intelligent enough to have any perspective...I doubt they are). Fish tank fish are raised from egg to adult in tanks of one sort or another.",
"Believe it or not, [fish can get depressed](_URL_2_)! Anecdotally, as someone who works in the aquarium industry I've heard countless stories of fish that acted differently when moved to a different tank: for instance, when moved to a smaller tank they sat on the bottom, were less active, displayed stress coloration more, and refused to eat. On the other hand, fish that were moved to a larger tank became much more active. (And not just inappropriately small tanks, but also tanks that were big enough, if a little cramped.) Fish also display differences in behavior when decorations are added or removed, when other fish in the tank die, etc.\n\n/u/equus007 is partially mistaken, in that while *most* fish you find in aquariums were probably captive raised, if not captive bred (the difference being that captive raised fish may have been harvested as eggs or very young fry, but not actually bred from captive parents) and lived their whole lives in aquariums, not all fish are. In fact, the vast majority of saltwater fish are wild caught. Only some species of clownfish, seahorses, *very recently* some tangs (including [blue regal tangs](_URL_0_)), and one or two other species are bred in captivity. All other saltwater fish are wild caught, so they're definitely not used to captivity.\n\nAnd sometimes it shows. Some fish take well to captivity and adapt, easily switching their diet to include prepared foods like pellets and flakes and/or frozen foods. Some do not, and never accept prepared foods. Some never accept food in captivity at all! They get stressed out and can't calm down enough to eat.\n\nI don't think a fish has the capacity to understand the concept of *captivity*. I don't think they understand that they are in an *aquarium* in any sense other than the understanding that they're in a very different environment than what they're used to. Even captive bred fish have instincts that evolved for living in the wild that have to be either adapted for captivity or accommodated by someone keeping them. But they do absolutely understand the limitations of the environment around them. They understand the size and shape of the tank surrounding them. And they understand that this new surrounding is not *normal* until they get used to it and it becomes their new normal.\n\nEDIT: Also worth noting, it *totally* varies by fish. Some fish are very intelligent. Remember, \"fish\" is a broad category, almost like saying, \"Are mammals intelligent?\" Well, *some* of us are, eh? And you're more closely related to, say, a bony fish like Dory than that bony fish is to a shark, even though they're both called \"fish\". The family [mormyridae](_URL_1_) is quite intelligent - they have one of the largest brain mass to body mass ratios of any animal! Again, anecdotally, most saltwater fish seem to be pretty intelligent - as far fish go - especially puffers, triggers, and eels.\n\nIf you're willing to expand your explanation to include other undersea creatures, like cephalopods, they're absolutely intelligent enough to understand what an aquarium is (even if they probably still can't understand the abstract concept that is \"captivity\"). Octopuses have been known to crawl out of their aquariums and into nearby aquariums to snag some fish, and then back again to avoid getting caught doing it."
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"https://en.wikipedia.org/wiki/Mormyridae",
"http://www.nydailynews.com/life-style/health/depressed-fish-controversial-tool-developing-anti-depressants-article-1.3569565"
]
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|
20r5ou | how a country "annex" a portion of another country without it's permission? | Edit: How CAN a country "Annex" a portion of another country without it's permission?
I'm sure I've missed several details, but how can Russia just say, "Hey, Crimea is part of Russia now." Furthermore, how is the world just letting this sort of thing happen? To me it's like Canada saying, "Hey, Montana is part of Canada now." It just sounds really odd to me.
| explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/20r5ou/eli5_how_a_country_annex_a_portion_of_another/ | {
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"It's illegal in every domestic (Ukraine) and international definition. But what do you do? Start a war with Russia?"
]
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[]
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5408ry | why does it help to vent about our problems? why is it harder to get over them on our own? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5408ry/eli5_why_does_it_help_to_vent_about_our_problems/ | {
"a_id": [
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"For much the same reason it helps you learn a topic by trying to teach it to someone else. Our brains do not always process information in the most coherent or logical way. When going through some kind of problem or emotional turmoil, your brain will attempt to process all of that information at the same time, which can lead you to feel very confused and disoriented.\n\nWhen venting to someone, you're formulating your problems into a coherent statement to try to explain it to them. In doing so, you're also helping to organize your own thoughts and understand all of the information you're taking in."
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6adtx6 | why are mice bodies viewed as analogous to human bodies in laboratory settings? | Sometimes I'll see a "medical breakthrough" where researchers will find something happening in a mouse's body, then they'll apply the same principle to the human body. Is this really sensible? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6adtx6/eli5_why_are_mice_bodies_viewed_as_analogous_to/ | {
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"Because mice are cheap.\n\nIn theory, researchers could use virtually any mammal for the types of tests they're running with mice. But mice are a lot easier to keep, breed and feed than, say, mountain lions.\n\nOnly once you've run what tests you can on mice do you start moving to organisms closer (in the particular way need you) to human beings. So if you're testing on monkeys, chances are the basic research in your field has already exhausted the possibilities of using mice.",
"Mice are mammals, so they have a lot of similarities to humans. And they are cheap and easy to breed and breed in large numbers, so it's quite easy to get a number of sample groups for testing. Testing on primates would give more analogous results, but they are much more difficult to raise and keep compared to simple mice.\n\nThey aren't perfect, and many of the results of a mouse study may not apply to humans. But it can give some validity or reveal potential problems before testing on actual people.",
"We're both mammals, with all the same organs and subsystems.\n\nJust the 'code' that grows them says small, four feet, big ears and tail, not big-ish mostly hairless ape with freakish big head. There isn't a single bit of you that you can't find in a mouse, but with a different shape, and smaller. The microscopic things (cells, neurons) are all more or less identical, according to breed of rodent.\n\nMice conveniently have quick breeding/life cycles, so things like cancer develop quickly and you can see multiple generations of effects in a reasonable time period.\n\nThings that can accumulate for decades in a human with little or no ill effect will have more immediate effects in mice. Mice are WAY more prone to develop a tumor than humans. The LD-50 model for toxins is extremely skewed, too. However, the fact that a mammal similar to us CAN have negative (or positive) effects from something is useful.\n\nAlso, (unlike human experiments and even vivisection done from the 19th and early 20th century with a brief of stopping before the nazis revived the practice, then stopped again, except in secret) most people don't care much about what happens to mice.\n\nMice and rats are overall way cheaper than rabbits, cats, dogs or monkeys or volunteer humans for a trial, for the very early testing of various pharmaceuticals, and a lot less 'noise' happens when people find out you're using them.\n"
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3m888p | currently in us history class learning about shay's rebellion. i have no idea what's going on, can someone explain what it was to me? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3m888p/eli5_currently_in_us_history_class_learning_about/ | {
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"Shays' rebellion (his name was Shays, so the apostrophe comes after the s) was a rebellion by farmers in Massachusetts. It was (mostly) bloodless, but it really spooked the founding fathers. They realized that the Articles of Confederations created a central government that was far too weak. A few years later, they scrapped them and wrote the US Constitution"
]
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||
2d3lc9 | why is it so hard to install a new os on a phone? | On normal PCs, installing a new OS is easy. You pop in a disc or a USB drive with the OS, go to your BIOS settings and change the boot order (or hold C on a Mac) and you're done. On a phone it's a huge hassle to do it, and many phones don't support it at all. Why is this? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2d3lc9/eli5_why_is_it_so_hard_to_install_a_new_os_on_a/ | {
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"The OS that comes on your phone is 'approved' or 'authorized' by the carrier(s) its meant to be used on. This allows then to add in bloat ware and make sure you cannot use features that rely on a paid service.\n\nIf you where able to install a fresh operating system, there isn't restrictions, and you can hotspot for free, and not worry about OTA updates."
]
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|
3lte1s | how microwave ovens work, and how they keep the microwaves from escaping? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3lte1s/eli5_how_microwave_ovens_work_and_how_they_keep/ | {
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"A device called a \"magnetron\" turns electricity into microwaves (a type of electromagnetic wave), which are directed into the main chamber with your food. If you look inside the main chamber, you'll see a \"grille\" in the side with a bunch of holes-this is where the microwaves come from.\n\nMicrowaves can't pass through metal, so the entire inside of the microwave is lined with metal, including the window (basically a metal screen or a sheet with lots of little holes). It forms a sealed \"cage\" to keep any microwaves from escaping, as well as helping bounce the waves around to cook food evenly.\n\nAs for actually heating up food: Microwaves happen to be the correct frequency to interact with water. Basically, it makes water molecules vibrate, which creates friction, which creates heat. This is why \"wet\" stuff gets so much hotter so much faster.\n\nChocolate chip cookies are a good example. The chips have a lot of fat, and therefore water. The cookie is dry, and has very little water. This is why a few seconds in the microwave results in a warm cookie with molten lava temperature chips.",
"Does that mean the bowl that gets scolding hot before my food is heated has water in it? ",
"I have watched **The Engineer Guy's** [video](_URL_0_) on this topic. I love his videos. Check it out!",
"To keep them from escaping, keep them plugged into the wall and up high on a counter. Microwaves are afraid of heights. ",
"Microwaves sound tiny because of \"micro\", but actually they travel in huge wave shapes, so they can't get through those small holes in the front screen.\n\nBonus: the waves are so big that if a tiny gnat were to get inside when you ran the microwave with a plate of food, it would probably not be harmed."
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5w0nir | why would a nuclear war be the end of the world? | Perhaps I'm being naive but I'm aware of hundreds of nuclear tests that went on in the Nevada desert/atolls etc. as well as many other nation's tests. Why would an all-out nuclear war be any different? You hear of the creation of a nuclear winter/doomsday scenarios etc. Thanks | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5w0nir/eli5_why_would_a_nuclear_war_be_the_end_of_the/ | {
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" > Why would an all-out nuclear war be any different?\n\n1. A much greater concentration of nuclear fallout. Setting off one or two weapons a year in underground tests produces almost no nuclear fallout. Setting off a thousand weapons in counter-force ground bursts is going to throw a huge amount of radioactive debris into the air all at once.\n\n2. Firestorms. Put simply, the desert doesn't burn, but cities and forests do. A major nuclear exchange would result in massive firestorms. The \"Nuclear Winter\" theory says that the amount of smoke and soot produced by major cities and huge swaths of land burning out of control for weeks or months would cause a catastrophic cooling effect.",
"First, other that a few tests, most nuclear bomb tests are done deep underground so that radiation isn't an issue and the rest are done in deserts or islands where nobody lives. If a nuclear bomb went off in a major city, not only would it kill lots of people and destroy lots of builds, but nobody could live there for hundreds or thousands of years.\n\nNext is the number of nuclear weapons. See if we are two countries at war and I decide to use a nuclear weapons, there is the issue of escalation. I shoot one at you, you retaliate by shooting one at me. So I shoot another and so on. Well I don't like that so I decide to shoot all of my nuclear missiles at you in the beginning in hopes of killing everyone in your country before you can fire yours. But you are ready for that so you fire all of yours in a \"if I am going you are coming with me\" strategy. Then everyone dies. Plus now instead of 1 or 2 it is 300-500 missiles going off.\n\nThis leads to nuclear winter. All those missiles cause a lot of dust and ash to get thrown into the air. All that dust and ash blocks a lot of light so it gets cold.This means with the weather and possible starts an ice age depending on how many nuclear weapons go off.",
"People do exaggerate the effect of nuclear bombs sometimes. You are correct. A few bombs would not end the world. Although they could kill millions of humans. \n\nAt the same time, thousands of bombs blown up in a short period of time above ground is different than a few hundreds of bombs over decades with many of them underground. \n\nKicking up large amounts of dust is a big deal though. In the past things like volcanoes and asteroid strikes have darkened the sky for years or decades and it's been a big deal. Mix in radioactivity to the dust and it's a huge big deal. "
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9nv6rt | how do pharmaceutical companies manufacture drugs | If they produce 500 different medications, do they have 500 separate assembly lines?
What do they start with? I'm guessing not buckets of pure elements... Where do they get the materials? Who manufactures those?
If a company wants to start producing a generic variant of a drug, is it up to them to figure out how to assemble the active molecule? Do they get the chemical "blueprints" of the molecule's structure from somewhere or do they buy a batch of the original drug and hand it over to a team of engineers to analyze? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9nv6rt/eli5_how_do_pharmaceutical_companies_manufacture/ | {
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"They produce each medication per batch, they may use the same machines and equipments depending on what type of medicine they would produce, like if it is a tablet or a capsule. They produce, clean the machine, then repeat basically. They get their raw materials from manufacturers of these. They use A LOT of raw materials, you need a whole semester to learn those. Lol. \n\nProducing generics depends on if they have the patent or not. If a certain drug is patented by a company, other companies can't produce it. Other companies could wait until the patent expires, then that is when they can produce that generic or make their own brand. All these drugs' specifications, ingredient, use, etc are written in a \"monograph\", usually compiled in a \"pharmacopeia\". Basically a book of drugs. Lol. \n\nI hope this helped (and I hope it didn't make things harder to understand). Sorry I used some technical terms. And also if I made some mistakes, feel free to correct me.",
"Various companies do nothing but make refined products for other companies to use to make a final product. Dow Chemical/Dupont is major player in that field. Alot of brands of OTC and generic medicines are made by a company named Perrigo.",
"It's possible to add and combine various chemicals into distilled water, to get a reaction going and form an organic chemistry compound that's the drug. \n\nThen you pass this liquid through filters to remove impurities and bacteria. Then you vacuum-dry it in specialized ovens, removing the water and getting a powder of the chemical, dry, pure, and sterile. \n\nAnd finally you use robots in a sterile clean-room to squeeze the powder into the shape of pills.\n\nFrom start to finish, the process doesn't require assembly lines as much as various big bulk tanks and mixing devices, and stainless steel pipes to move the liquids from one stage to the next. May require assembly or robotic lines at the pill-forming stage. \n\nBut pipes, tanks, and various equipment can be cleaned and sterilized for production of a new lot or a different drug, by passing hot water with maybe some soap through, then hot distilled water to \"rinse\", then super-hot steam to sterilize everything. Which is why the equipment is made of stainless-steel, which will not corrode and can withstand the pressures and temperatures of hot steam, repeatedly.\n\nThe drug manufacture sector is controlled by the FDA, who require sterility and lots of testing before they allow the drug to be sold publicly. Usually when inventing a new drug (new chemical formula), the inventing company will have patents (that typically last 17 years), and nobody else can make that. \n\nAfter the patent expires, anybody else can be free to copy the formula and make \"generic\" variations of the drug, but the FDA still requires each company that makes the drug to provide testing and proof that it's sterile and safe for use. So, even for generics, the manufacturer still has to go through testing, clinical studies, and audits from the FDA, before they can sell.\n\nAll of that is a big investment, takes several years to do all the studies and audits, so what you see is that only a few companies, who already have the facilities and manufacturing devices in place, bother to try to \"copy\" drug formulas and make generics. And they only do so if the price of the \"generic\" can offset 2 years of clinical research and testing with no sales."
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2faw77 | the rotherham child sex scandal, specifically the facts and figures | The enquiry found that 1,400 girls were sexually exploited:
_URL_0_
But the town itself has a population of only 250,000. 1,400 is about 5 per cent of that. So not 5% of the young women of the town, but 5% of the population of the town was exploited? One in every twenty people?
It just doesn't make sense to me. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2faw77/eli5_the_rotherham_child_sex_scandal_specifically/ | {
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"It happened over the course of 16 years, and frequently girls were brought in and out of the town. It wouldnt be 5% of the population unless it happened all at once."
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embwtu | how do aquatic mammals living in the arctic not get frostbite on their skin? | I understand that blubber insulates a walrus and keeps their core body temp from dropping to dangerous levels, but how does their skin keep from being damaged by extreme cold?
Also, from what we can tell do they get uncomfortable when there's a stinging -20 degree stiff wind blowing over their bodies? Do they seek shelter? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/embwtu/eli5_how_do_aquatic_mammals_living_in_the_arctic/ | {
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"Fur and chemical processes that produce heat. Remember that bodies are mostly water so it takes a lot of energy to increase the temp and a loss of a lot of energy to decrease the temp. Humans get frostbite easily in their extremities because the himan body withdraws blood from the extremities and doesn't spend energy to keep them warm.",
"So frostbite is a phenomenon where the cells that make up your skin get so cold that ice crystals begin to form inside the cells, which will eventually cause the cells to burst, which means the cells are now dead. \n\n\nCold weather animals have come up with some interesting ways of avoiding this. For mammals, they typically have very dense fur that can trap a layer of air against the skin, and that layer of air is a wonderful insulator. Otters are a supreme example of this. One square centimeter of otter skin has about as many hairs as an entire human head, and when hairs are packed that tightly together, cold air and water can't get in all the way to the skin. Even when they're swimming around in freezing water, the fur still keeps that insulating layer of air next to the skin. \n\n\nHaving lots of fat is also a great way to keep all the important parts warm, and sometimes an arctic animal CAN freeze to death if their fat layer gets thin enough, like if the animal can't find food or has suffered some long-term illness. But if the animal is healthy, the fat layer will give the skin just enough heat to keep it from freezing, but not so much heat that it's being wasted by getting sucked into the cold air or water. \n\n\nThe type of fat makes a difference as well. Water conducts heat something like 25 times more than air does, so critters that spend most or all of their time in freezing water need extra heavy-duty fat, and that's blubber. If you've ever had steak or something, you've probably seen that land mammal fat is pretty blobby and jiggly, but blubber has a completely different structure. The fat is incredibly dense and firm (here's a photo that shows how thick whale blubber is: [_URL_1_](_URL_0_)) \n\n\nAnother thing we see in the bodies of animals that live in cold water is that their skin temperature is usually about the same as the surrounding water (Animals like whales don't have a fur layer to trap warm air, remember) so the skin is pretty cold, but still a bit above freezing, so ice crystals won't form. The blubber helps make sure that the skin doesn't freeze, while keeping all the internal organs and muscles nice and toasty. And the reason the skin is kept cold is to prevent loss of heat. If the skin was kept warm, the cold water would constantly be sucking that heat away, and it takes a HUGE amount of energy to keep producing that much heat, so rather than wasting that heat by trying to keep the skin warm, whale bodies allow the skin to be cold, and keeps the heat inside. \n\n\nAs far as what it feels like for the animal, we're still not entirely sure. We know that they have about as much feeling in their skin as humans do, they can feel it when something touches them, and they appear to be able to sense heat and colds just as well as we can, but as far as how they \"feel\" about that cold, we aren't sure. It doesn't seem to bother them, which makes sense, because it wouldn't work too well to have a critter that spends its life in freezing water and then make it be in agony 24/7. So probably they sense the cold, but their brains just don't translate that information as something unpleasant or painful or bad. \n\n\nThen we have arctic birds, who have their own ways of coping with cold. They have dense feathers, of course, that they can fluff up to trap insulating air next to the skin, like arctic mammals do, and many bird species also use shivering to generate heat, just like people do. \n\n\nThere are a few species of birds that have feathers on their feet (like willow ptarmigan) to help keep them from freezing, but most birds don't (like penguins), so they use a special kind of circulatory system called a countercurrent blood exchange. Basically, you have one main artery that brings warm blood from the core down to the feet, and another main artery bringing cold blood from the feet back to the core. Now, this could potentially cause a problem, because if you pump cold blood directly back to the core, that cools down the core, and then the body would have to keep using enormous amounts of energy to re-warm the core, and that's just a ridiculous waste of energy. \n\n\nSo what happens is, the cold blood artery lies right next to the warm blood artery, and even has little veins that come out and wrap around the warm blood artery. This way the cold blood gets warmed up on its way back to the core, and so the core won't get cooled down. And even though the cold blood artery is taking some of the heat away from the warm blood as it travels down to the feet, it's still plenty warm enough to keep the feet from freezing. \n\n\nAnd then of course there are the animals that migrate with the seasons. That certainly helps a lot of species, and you don't need to have such a highly adapted body to cope with the weather. You just start wandering south when it gets cold in winter, and wander back north when it warms up in summer. Lots of bird species do this,",
"If they're in water, it's not cold enough to damage their skin via frostbite, otherwise they'd be in ice.\n\nAll water is, by definition, warmer than freezing."
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b0rhae | why does a cd/dvd reflect rainbow colours when it is placed under sunlight? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/b0rhae/eli5_why_does_a_cddvd_reflect_rainbow_colours/ | {
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"text": [
"Because the way light bounces off of it (because of the foil the data pattern is engraved on stck to the clear plastic spine or whatever) the light is scattered revealing the various notes (colors, more or less) enclosed in white light"
]
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||
2hl8yw | why is our easier to have deep conversations with people late at night, but not during the day? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2hl8yw/eli5_why_is_our_easier_to_have_deep_conversations/ | {
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"At night it's dark. We feel hidden and protected. Ready to open up.\nDuring the day it's daylight. We feel exposed in the light. Easier to be judged when one can be \"seen\". ",
"I can't explain the science behind it, but I think there are several factors. First, there's what /u/chiefinspector2 said below about the dark causing us to feel hidden and protected. Then, also, we tend to be a little more inclined to think about serious topics at night, when our energy levels are at a low ebb; and at the same time, when we are tired, our inhibitions are lowered."
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4hc5b4 | when mass is fast, time slows but what it is that actually slows? what is time? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4hc5b4/eli5_when_mass_is_fast_time_slows_but_what_it_is/ | {
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"Here's a neat way to think of it. You're always moving the speed of light. Always. When you're not physically moving, 100% of that motion is along the time axis. When you're physically moving, you borrow some of that motion from the time axis and apply it toward one of the three spatial axes. If you were physically moving at the speed of light (100% of your motion is physical), your motion through time would be zero. Does that help any? Or just make things confusing (in which case, I apologize)?\n\n^^Edit: ^^typos."
]
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||
211nkt | is there any real reason for the 'l' and 'r' on headphones? does it matter what ear they go in? | I can't say I've ever noticed a difference but I'll be damned before I put the 'R' headphone in my left ear.
Edit: Well that was fast. Thanks guys!
Edit edit: Some more fantastic replies from people, thanks again! I especially liked the examples /u/thesweetestpunch gave - and with one of my favourite songs too! | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/211nkt/eli5_is_there_any_real_reason_for_the_l_and_r_on/ | {
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"Many headphones are designed to fit more comfortable in or on your ear. The left and right identifiers help do you know which goes where.",
"Some TV and music is mixed for going left to right, or right to left. In those cases, or if you have a ear buds that are made to fit the ear, you need to heed the L and R.\n\nOtherwise, nope!",
"They can be shaped differently for ergonomics, but they also retain the 3D effect of what you are listening to. If it is music then maybe it doesn't matter, but for a movie where a car drives left to right across the screen, having the sound go right to left would be confusing.",
"Many songs have unique left and right channels -- most games do too.\n\nIf you play a game and put your headphones on wrong, it can be pretty disorienting.",
"Depends on what you listen to most. It's less obvious in music, and less obvious with headphones than it would be with a full surround setup, but in movies and some video games, the sound is mixed to contribute to the illusion of movement and space. If you have your headphones on backward, that car zooming by left to right will sound like it's going right to left instead.",
"Many studio engineers will mix the different instruments based on their location during a performance.\n\nExample: If you're watching a band play and the bass player is on the right side of the stage and the guitar player is on the left, the recording engineer might \"pan\" the instruments to match their positions. \n\nThis is one basic example, but hopefully it will keep you from feeling OCD when you make sure the R is on your right ear ;)",
"Almost all audio since the 1960s is mixed in stereo, meaning that the left and right headphones/speakers are giving you separate mixes of sound, which combine to create a full mix and often a \"three-dimensional\" effect (this is felt more in speakers; when you sit in the sweet spot of good speakers, elements mixed to the center of the mix - like lead vocals - will seem to be coming from the space in front of the center of the speakers). Moving something to the left or right speaker is called \"panning,\" and is a big part of making things sound the way they do. \n\nYou can hear this most obviously if you listen to a late 1960s mix, like a Beatles song. The left and right channels are panned hard, meaning that some instruments will be only in one side or only in another. Listen to something like \"Eleanor Rigby\" in just the left side, and then just the right side. Assuming that your headphones settings aren't cancelling the stereo image, you'll hear very, very different things in each. \n\nOne of the most important effects that panning can have is whether you have what it called \"audience perspective\" or \"[musician]'s perspective\". Meaning, from the audience, a drummer's ride cymbal is on the left and the hi hat cymbal is on the right. By panning the cymbals one way or the other, the audio mixer can make you feel like you're in the audience, or they can make you feel like you're sitting right behind the drums. You may not consciously be aware of this effect, but it really changes the emotional effect of the music.\n\nAlso, as others said re movies: if a car is racing on the screen from left to right, and you wear headphones backwards, the sound won't match the image. ",
"Try playing counter strike with your headphones reversed."
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8304gg | not sure if the right community to ask, but why don’t cemeteries bury our loved ones vertically? wouldn’t it save more space to do so this way? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8304gg/eli5_not_sure_if_the_right_community_to_ask_but/ | {
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"It would be MUCH harder to dig, as you'd need to dig far deeper so the body would have sufficient amount of dirt covering it. ",
"There is a practical reason and a religious/tradition reason. The religious/traditional reason is pretty self explanatory. In past times people tend to be burried with their heads faced a certain way. Facing the sun, or a holy place. Tradition tends to stick when the actual reason has long been forgotten. Also it has some symbolic meaning. You are literally placing your loved one to rest. Hence, why alot of coffins tend to look like a bed and are 'cozy' for a lack of a better word. \n\nThe practical reason is that it is much much easier to dig a horizontal hole. You have to dig way deeper with a vertical hole and you require specialized equipment. With a horizontal hole you can pretty much use a shovel.",
"If the problem were to save space, I guess that bodies would be burnt more often, and not buried",
"Possibly also horizontal makes it easier for mourners to think of burial as \"laying someone to rest\".\n\nVertical would be more like \"leaving someone standing around underground\", which would probably make the mouning process a little more interesting to deal with psychologically...",
"I'm surprised no one's mentioned how it could be because as the body decomposes the bones would collapse and become a pile. Or am I being stupid? ",
"Not an answer to you question, but there’s a farm near where I grew up that according to local legend, the first owner had himself buried vertically in the corner of the field, facing the house, so he could eternally keep an eye on his slaves. The house is supposed to be haunted, of course. "
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5ghmzk | how did people in the 50's and 60's look so good when their diets were basically bread, cigarettes, donuts, and bread? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5ghmzk/eli5_how_did_people_in_the_50s_and_60s_look_so/ | {
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"I imagine it was smaller portion sizes, less of an emphasis on preservatives and chemical additives in prepared foods, and due to a lack of TV, people generally did not lead sedentary lifestyles. ",
"It was before the era of corn syrup: dirt cheap sugar that has been added to everything. It's in your tomato soup.",
"I don't understand why you think their diet was all complex carbs. In fact, [if anything we eat a lot more grains today than anytime in the past century](_URL_0_). Moreover, the total calorie intake has increased as well.",
"There were like 2 channels and most of the TV was lame AF. People still played sports for fun! Movie theaters were great fun but there was no home video, so it was kind of a treat. No video games either. Basically people had to read or go outside. \n\nAnd while they didn't necessarily eat healthy foods, they also didn't eat constantly the whole day munching on bags of whatnot. You ate a meal with your family and then out of the house. ",
"Selection bias.\n\nThe images you see in the media from that era are much more likely to show young looking, trim, well groomed people, often with profession makeup, lighting, and photography. Ugly people are are lot less likely to be memorialized. In addition, the mainstream fashions of the day tended towards a neat, clean, conservative look (at least until the late 1960s), which also helps.\n"
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2j8k2x | if power stations can use steam to spin turbines and produce electricity, why haven't we set up something near a huge lava flow and harnessed that energy? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2j8k2x/eli5_if_power_stations_can_use_steam_to_spin/ | {
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"geothermal energy is a thing. You don't tap the energy from the lava on the surface, instead you tap the energy from the heat deep down in the earth. It's not exactly cheap, and apparently it can have some repercussions.\n\nArticle [here](_URL_0_)",
"Huge lava flows imply a degree of danger and uncertainty, and they're generally not that accessible or commonplace. As /u/limbodog notes, we do use geothermal energy in places where it is advantageous, but you can't simply 'dig and hit lava' anywhere you want. ",
"Because the lava might randomly destroy what you set up?"
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5ytw3q | why do men shave their beards downward, but women shave their legs upward? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5ytw3q/eli5why_do_men_shave_their_beards_downward_but/ | {
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"Legs are below your arm level so the natural motion is upwards. Beards are above your arm level so the natural motion is downwards. "
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ewcd5u | how do parking machines read a validation stamp and know not to charge you? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ewcd5u/eli5_how_do_parking_machines_read_a_validation/ | {
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"I would guess that the stamps are provided by the company and programmed into the machine. Using technology more primitive than facial recognition software, when the machine recognizes one of these symbols, it applies a '0' in the calculation of time x $ or it overrides calculation to open the gate."
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1u8741 | what are liquid assets? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1u8741/eli5_what_are_liquid_assets/ | {
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"Liquid assets are cash or assets that are as good as cash (and hence can be traded directly), or goods that can easily be convertible to cash.",
"Liquidity in investing is a property dictating how easy it is to trade away for something else. For example, some goods have very high demand, and so are easy to trade in return for something you want. On the other end, some items are not in high demand, and so are hard to get rid of.\n\nThe ultimate liquid asset is cash, because it is accepted everywhere. Precious metals are almost as good as cash, and so are good liquid assets as well.",
"Assets can be liquid or illiquid. Liquid means that you can really easily trade them for other stuff; illiquid means that it's difficult to trade them for other stuff. Examples:\n\n**Liquid**\n\nUS dollars. A lot of people want them. You can pretty much trade US dollars for anything. Plus because so many people want them you can find someone to trade with really quickly and easily. You can walk down the street and find a buyer plus get a great value for your dollars.\n\nSo if you want an investment and you want to be able to \"cash it out\" immediately then liquid assets are pretty great.\n\n**Illiquid**\n\nAn antique. Not a lot of people want them; most people wouldn't accept an antique as payment. Plus because so few people want them it takes you a lot of time to find the people who do. You can't walk down the street and find a buyer (easily), plus if you do find a buyer you may have to sell your antique for way less than it's worth.\n\nSo if you want an investment and you're OK with not being able to easily \"cash it out\" then illiquid assets can be pretty great.",
"Liquid Assets, Cash, it's in its most distributable form. "
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63tr3v | why is it that mlb calls aren't reviewed like nfl plays are? | I was browsing along my timeline when I saw an article about "The Worst Calls In Baseball History". Enclosed was a bunch of videos with blatantly obvious terrible base-calls. Why can't they be reviewed and overturned like in the NFL, where the "booth" can review the plays? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/63tr3v/eli5_why_is_it_that_mlb_calls_arent_reviewed_like/ | {
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"They do have reviews...You can challenge 2 calls per game. You can not challenge balls/strikes.",
"They do review calls. \n\nBut the system was not put into place until 2014. So the article you're referring to was probably from before then. ",
"[There is replay review in MLB now](_URL_0_), and has been for a couple years... I believe at first it was just used in playoffs and is now used more widely throughout the entire season.",
"There is controversy about this in almost every sport. First of all reviewing the footage takes time and if there is a need to review the footage you need to stop the play as you might have to change the call before you move on. It may help in some sports to have another judge who have the time to review the footage in real time but it still slows the game down. Another reason to not implement video reviews is that not all games have cameras and they may be of different quality. Of course this differs between leagues and the top leagues in the most viewed sports tend to always have high quality video productions. But this might not be the case in all events. This makes the games uneven as sometimes you have video judging and sometimes you don't. Requiring that all games have video production is quite expensive if nobody have bough the rights to show the video so people are unwilling to do so.",
"MLB is slow enough as it is. If they slow the game down anymore then the players will need to retire before the game even ends. "
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9go641 | what observations led to the interpretation that the inner core is solid? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9go641/eli5_what_observations_led_to_the_interpretation/ | {
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"When there is an earthquake, the \"sound\" is transmitted through the Earth in two kinds waves, P waves and S waves. P waves are compression (in and out relative to the core). These waves transmit quite clearly through the Earth, so an Earthquake on one side can be detected on the other side. S waves are shear (from side to side), and only solids are strong in sheer. The S wave sound does not go through the center, because there is a liquid region in the core. Most interesting, the P waves can be detected reflecting off something inside the Earth, and bouncing back at a time too short for them to be reflecting off the solid surface on the other side of an all-liquid core. Thus we need a liquid part of the core, plus this is where the magnetic field comes from, and a solid innermost core for the P waves to bounce off."
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43mqxi | would there be any benefit if we removed the democratic and republican parties from the american system? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/43mqxi/eli5_would_there_be_any_benefit_if_we_removed_the/ | {
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"Moot point. The Constitution does not allow the banning of parties and if they were gotten rid of two new ones would take their place. It's a consequence of the way that we elect our leaders."
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6rytil | immunosuppressants for organ transplant/blood transfusion? | So, I know that if someone has an organ transplant, they have to be on immunosuppressants for life so their body doesn't attack the new organ.
Why do people who have blood transfusions not have to be on immunosuppressants? Doesn't blood also contain "different" DNA that the immune system would attack? What's the difference between a blood transfusion and an organ transplant in terms of care after the procedure? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6rytil/eli5_immunosuppressants_for_organ_transplantblood/ | {
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" > Doesn't blood also contain \"different\" DNA that the immune system would attack\n\nNo. Neither red blood cells nor platelets contain a nucleus and therefore no DNA. And to be precise, not the foreign DNA is the main problem - although it will be detected too, eventually - the expression of \"foreign\" MHC (also called HLA) molecules would be the problem. But red blood cells and platelets don't bear those. That is pretty much the point of the AB0 blood system. And in most blood transfusions white blood cells are removed before the donated material is used. So only the blood type has to match. Plus blood components are really short lived (red blood cells about 4 months) and will eventually be replaced by recipient cells, in contrast to organs like liver or kidneys that would stay for years inside the recipient, optimally until death."
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31wrwm | why anyone would buy swiss 10-year bonds with negative yields. | [Article for reference: Switzerland becomes first to sell 10-year bond at negative yield](_URL_0_)
If a cash position for 10 years gives a better yield than the bonds, why buy the bond at all?
And if these bonds are actually being sold, why wouldn't someone simply short sell them all? I'm remembering a brief period during the 2007-8 crisis where Warren Buffett sold/shorted a bunch of short term US Treasuries when yields were negative.
You don't have to ELI5 here - I actually have a math, econ, finance background. But there is something I'm missing here.
Edit from mobile: Wow. Way more response that I ever expected. Good karma to you and you kin! | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/31wrwm/eli5_why_anyone_would_buy_swiss_10year_bonds_with/ | {
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"Ahh I'm glad you've asked because this is something I've recently learned and I'm more than happy to enlighten you!\n\nThe answer involves the storing of cash, and the risks associated with that when you approach a certain wealth level. The FDIC insures depositors up to $250,000 per account, but what if I have $100,000,000? Well, aside from it being a bit ridiculous to have 400 checking accounts (so as to ensure all of the cash is protected by the FDIC), it boils down to the fact that sometimes, taking a GUARANTEED loss of 0.05% is often times better for someone with that much money than to put it into something where there's a greater risk.\n\nTL;DR - sometimes it makes sense (when you have exorbitant amounts of money) to know that you'll only lose X% as opposed to other market alternatives where your risk could be much higher\n\n**EDIT:** Admittedly, my answer doesn't address the entirety of OP's question, and actually leaves out several pertinent factors to consider. There's a lot of information floating around this post and I'm trying myself to wrap my head around it. Inflation, exchange rates, and overall diversification/tax planning strategies are extremely relevant to understanding the correct answer",
"Notice the denomination. The Swiss bonds are paid in Swiss Francs. If you expect the Franc to appreciate with 5 % relative to your currency, taking a 1 % loss in Francs is acceptable, because you still make a 4% profit.\n\nAlso, if I remember correctly, the Swiss Franc was tied to the Euro, meaning you actually could expect it to either appreciate or depreciate shortly relative to the Euro. We almost saw the same in Denmark, where the national bank completely stopped selling some bonds, in order to defend the tie.",
"Why not put it in gold instead?",
"The largest driver for negative bond yields is central bank buying. The mandate of the central bank is full employment and positive GDP, not to make money. Central banks are the ultimate dumb money as they are purposefully acting counter cyclical to the market. They buy bonds when prices are high (like today) with a goal of pushing prices higher and interest rates lower. \n\nInterest rates are artificially low due to this buying. Take the central bank bidders out of the market and the price of bonds would fall causing yields to rise.\n",
"If there's deflation, you can still make a profit with negative yield bonds.",
"A few good answers here. You also have to distinguish between nominal and real rates. Real rates are the Nominal rate (let's say -0.5%) minus inflation. Nominal is the rate you get before inflation/deflation. If you have deflation of -2%, ie, price of assets is going down, then Real rates = -0.5 - -2 = +1.5%\n\nPretty sure that's right. Happy to stand corrected.",
"To sum up other answers and add my own ideas\n\n1. you believe the Swiss Franc will appreciate faster than that negative yield in the medium term you decide to hold your bonds (3 years)\n\n2. You're plan on retiring in Switzerland and do not want to expose yourself to currency risk AND expect bond prices to go up as markets correct in the short term. Worst case scenario you lose a bit of cash. Best case scenario prices shoot up and you make a bit. This is assuming markets correct and there is a flight to safety (sovereign guaranteed debt.\n\nWhats the worst case scenario here? In a year you regret your decision and take margin against your bond position and use that cash to buy something else? With the Euro dropping so much this year, parking your money in francs isnt the worst idea if you're looking to maintain cash in the coming months to see how things play out.;\n ",
"It has to do with the real value of a currency and the risk you are willing to take. Let's say you invest the same amount in US bonds and Swiss Bonds. The Swiss bond loses 5% and the US bond gains 5%. But the value of a dollar drops 10% and the value of a franc gains 10%. Even though you gained dollars and lost francs, the US bonds actually lost you money in real terms while the Swiss bonds made you money.",
"Because even with a negative yield the risk to your capital is lower than buying high yield bonds that may be in a devaluing currency.\n\nEssentially it's a safer place to keep your capital in an uncertain market.",
"There are a few answers to this, but I think one of them not to overlook is:\nPeople with money aren't always rational. I'd argue that this is *usually* a bad decision.\n\nHowever, there are some conditions that make it worthwhile if they are all met, such as:\n\n1) They specifically want Swiss Franc denominated currency\n\n2) They are incapable of keeping their cash secure for free (no FDIC insurance or equivalent)\n\nEssentially, this becomes the price of holding large amounts of cash in the form of Francs for large, institutional investors.\n\nHowever, it's also worth noting that greater fool economics and QE are alive and well in this world -- if you think that bond yields are going to go down below -1%, then it's rational to view the bonds as having some degree of upside potential. How rational it is to think that will happen with Swiss Francs, though..."
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tqkwq | internet "security" | What is it? What does it fight against? How do you improve it? What makes something "insecure?"
EDIT: What threat does insecurity have? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/tqkwq/eli5_internet_security/ | {
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"When you connect a computer to the Internet, you allow other computer the possibility to connect to it as well. This allows people to connect to you computer without your permission. Internet security is the attempt to 'secure' a computer against these unwanted Internet connections."
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2d90k5 | how do we guide probes and satellites to orbit other space bodies, saving them from all the space debris, asteroids, meteors, etc? | I understand that the space is really big and has lots of really big space, but how do we navigate satellites and probes like Cassini-Hugyens, Voyager, Curiosity, etc through all the space ? Do they have some kind of automatic collision prevention system or do we do it manually (though it seems improbable when it takes 2 hours to send/receive instructions for Cassini)? Do we "know" the paths and orbits of the asteroids and other such space bodies when we send them out there ? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2d90k5/eli5_how_do_we_guide_probes_and_satellites_to/ | {
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"We don't do anything. If a meteor is going to hit a probe we will have no idea until after the collision occurs, even then the probe might just stop sending data and that'll be it.",
" > Do they have some kind of automatic collision prevention system or do we do it manually\n\nNeither. We just point them in a direction and let them go.\n\nSpace is really, *really*, **really** big, and really, *really*, **really** empty. If you don't put a ton of time and effort into *trying* to hit something, then you almost certainly won't hit anything.",
"To give you an idea....in the most densely part of our solar system, the asteroid's bell, the distance between one asteroid and another one tends to be hundreds of miles apart (an approximation I read once said that every asteroid with a diameter of 1 meter or more has 4000square kilometers for himself)"
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2eq4bn | what would it take to classify isp's as utilities? | If we wanted to change something starting today, what would it take? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2eq4bn/eli5_what_would_it_take_to_classify_isps_as/ | {
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"Quite a few things would have to happen. \n\n\n\n1) The average American would have to be more informed. Many people don't know that you can only get 1-2 ISP's in a certain area. Many believe that there is competition in the internet market when there isn't. More Americans need to realize that 50 mbps isn't fast and that 1Gbps is possible. In other words the more people that are informed the stronger the public pressure. \n\n2) Young people need to start voting. Despite what you hear on Reddit, most people above the age of 30 are very ignorant on technology. Most people above 30 have spent a significant chunk of there life with little to no technology. I doubt most of them know that there is little competition in the ISP market. Older people are disproportionately represented in Congress so there interests are represented more. \n\n3) A change in paradigm among older Americans. Technology is seen by many people above the age of 40 as being a luxury. Many don't realize that technology is more important than ever. When most people in congress are in their 60-70's you're going to have a hard time passing technology bills that are favorable to the average consumer. \n\n\nOverall I see the main problem being that most Americans aren't informed. As long as older people make up a majority of the voting block you won't get anywhere on ISP's being reclassified. The average 60 year old voter doesn't care about ISP regulation. They will vote for congressmen that favor \" Free Market policies.\" "
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3ikdcb | the difference between the effectiveness of antibacterial hand soap and hand sanitizer. why waste water to wash hands when you can can lather on some gel and be on your way? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3ikdcb/eli5_the_difference_between_the_effectiveness_of/ | {
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"Hand sanitizer does not remove dirt, it just kills certain bacteria and viruses. If you have blood, faeces, urine, mucous, or other potentially infectious fluids on your hands, it will not remove them not will it effectively kill everything. \n\nSome germs, such as C. difficile, are highly contagious and do not die when exposed to hand sanitizer. The spores must be washed away with soap and water. \n\nMost people do not properly use hand sanitizer and miss large portions of their hands, particularly between the fingers, around knuckles, nails, and on the tops of the thumbs. The palms and backs of hands are all that get clean in typical users, so germs are still lurking everywhere. ",
"Antibacterial soap is actually equally or less effective at removing bacteria from your hands compared to regular soap with warm water. \n\nHand sanitizer eliminates only some bacteria before it's absorbed into your skin, which is why it's not as effective. It also dries out your skin, which gives the remaining bacteria some material to take cover under (the dry skin buffers the antimicrobial effect as it passes through, versus open exposure). "
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1yn9je | why are so many people on reddit socially awkward? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1yn9je/eli5why_are_so_many_people_on_reddit_socially/ | {
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"I think it's a combination of 1) the fact that socially awkward people spend more time on the internet and less with friends in real life and thus post more on reddit and 2) it being a sort of running gag where people will exaggerate or fake their social awkwardness because it is expected of Reddit users."
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8ywddu | question about weight gain. looking for a more in depth explanation beyond calories in/out. | This is not a calories in/out question. I know how that works on the basic level, use it myself all the time. I'm questioning it more on a biological (?) level.
Let's use neat round numbers for this example and ignore the intricacies of water weight.
I'm 125 lbs. I eat a magic burrito that has 3500 calories in it but has a scale weight of 6 oz. I go weigh myself as soon as I finish that burrito. I now should weigh 125 lbs 6 oz. Fast forward however much time it takes to process that food. Now I weigh myself and I'm 126 lbs.
How? How is a food/drink/whatever that weighs less than a pound able to increase your body weight by a pound or more? How does that work? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8ywddu/eli5_question_about_weight_gain_looking_for_a/ | {
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"Your body is storing fat in fat cells not as solid lipids.\n\nWe can consider lard which is 763 calories/3 oz according to google. An 85 gram serving contains 85 grams of fat(lipids) and therefore zero grams of water. When your body breaks this down and goes to store this, it can't store the lipids directly so it packs them into cells *which contain water*.\n\nIf you were to eat a pound of lard you'd be consuming 4063 calories in 16 ounces. Your body will start packing this away and mix in 2.6 ounces of water turning your 16 ounces of lard into 18.6 ounces of fat tissue.",
" > How? How is a food/drink/whatever that weighs less than a pound able to increase your body weight by a pound or more?\n\nYour \"magic burrito\" really gets in the way of making sense out of this. Even if you consumed a 3500 calorie block of *pure fat*, it's going to weigh over 13 ounces. If you didn't consume anything else, you'd never be able to actually put on that pound of weight. You'd have to consume water or *something* to be able to properly store it."
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103b42 | what do people do with stolen cars? | My car was stolen last night. What happens to cars people steal. I've heard of stripping it for parts and other things. What are the chances of getting it back? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/103b42/eli5_what_do_people_do_with_stolen_cars/ | {
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"If they want to make money then yea they will most likely bring them to an illegal chop shop where they take apart the cars and sell the parts. \n\nI don't know what the odds are of you getting back but i hope you do."
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4ewchc | do all the instruments/speakers that we hear produce sound that can't be heard by us? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4ewchc/eli5_do_all_the_instrumentsspeakers_that_we_hear/ | {
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"Basically whenever you have a resonance somewhere, you have overtones, which are harmonic oscillations at a higher frequency. So when you strike a string tuned to 1kHz, you will also have frequencies at 2kHz, 3kHz, 4kHz and so on and so forth. This is a large part of what makes up the characteristic sound of instruments. The volume of each overtone is typically lower the further away from the fundamental frequency it is, but in theory will always go all the way to frequencies which we can't hear.\n\nBesides music instruments, you will have these oscillations on any moving part. The membrane of a speaker also oscillates, and it'll also have upper tones beyond what we can hear, even if it's a subwoofer.\n\nSo yes, they will. It may just be so low that you'll have a hard time measuring it.",
"The runout groove at the end of many copies of Sgt. Pepper's Lonely Hearts Club Band has a high-pitched 15 kilohertz tone put there by John Lennon to annoy dogs. Some people can hear it and some people can't.",
"ELI5 version is going to have to be a little long to get all the concepts in.\n\nYes. Absolutely. They are called overtones. They are what gives different sounds their characteristics.\n\nThe way sound works is, a thing vibrates a certain number times a second. That is called \"frequency.\" Western music usually has what is called A440 as the basis for its frequencies. This means that the A note vibrates 440 times a second.\n\nWhen sound hits the eardrum, it vibrates at the same(ish) frequency of that sound and sends that frequency to your brain. The brain interprets that signal to be music, or a speech, or a car crash or whatever.\n\nSo. Back to overtones. The reason why a guitar and a piano playing the same note don't sound the same is because of overtones. Something with no overtones just sounds like tone. [This](_URL_0_) is tone. Basically the frequency is just vibrating at 440 times a second exactly. It's sound wave is uniform and looks like [this.](_URL_2_) But different sounds don't really happen in that uniformed a fashion. [Here](_URL_1_) is an example of different real world sound waves. See how they go up and down before crossing that X axis? Those mini waves are what sets apart different tones and whatnot.\n\nThose waves are called overtones. You really cannot hear them as separate sounds, but their blend is what gives a sound a sound. Kind of like when you drink a Coke, you don't taste the individual chemicals and flavors, it's one distinct taste. Some of these overtones will happen above and below what the ear can hear, so you won't hear those specific overtones as part of the overall sound. But here is where is gets funky. Overtones affect other overtones. So even though you cannot hear them, you can hear their effect on other sounds.\n\nAn experiment you can try is to take a song in your music collection that is at a high bitrate and re-encode it at a low bitrate, say less than 100. A *lot* of those overtones will be missing and you'll easily be able to hear the \"hollowness\" of that sound.",
"It also depends on the source of the music. An analogue source such as a vinyl record or a tape will produce a lot of sounds outside of hearing range as discussed. They combine with audible sound to make the overall effect required. Digital, compressed recordings however are designed to remove all kinds of stuff outside of the audible range to reduce the \"payload\" and so the file size. They can sound very poor but I guess like Video recordings on tape the convenience over rides the poor quality and we put up with it.\n\nTLDR: yes, with vinyl, not necessarily with MP3.",
"Without getting too science-y (a lot of good answers are in this thread) I just want to say, yes.\n\nAny form of mechanical oscillation will produce \"sound\" if there's a medium to carry it. The frequency produced by the oscillation may be very high or very low. Consider the vibration of an earthquake. We can't \"hear\" the earthquake, but we sure can feel it.\n\nWhen it comes to sound, whales use frequencies far outside of the normal 20-20k range humans can hear, because they *can* hear them.\n\nSo instruments, speakers, motors, friction vibration, etc all can produce sound, and any of these sounds can exist in bands above and below our timpanic membrane's resonance range."
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6s8vkf | how does a huge building like a skyscraper go from a blueprint to a constructed building? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6s8vkf/eli5_how_does_a_huge_building_like_a_skyscraper/ | {
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"contractors look at the drawings. They bid on work. Then they build according to the blueprints. Do you have a more specific question? ",
"I am assuming you are asking how it goes from scale on plans to real life? Math. Take the scale it was drawn in, figure out what the life size measurements are, and boom. \nIf the plans where drawn in 1/2 scale, that means everything would be doubled off of that to make it full size. If a beam was 10 ft in 1/2 scale, then you would make the actual life size beam 20 ft. "
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3nb0y2 | why is it relatively easy to lift a person, but hard to lift a weight that weighs less than half the person's weight? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3nb0y2/eli5_why_is_it_relatively_easy_to_lift_a_person/ | {
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"It's because the weight is spread out, and you can use more muscles to lift it, giving you more strength.\n\nLet's say you're attempting to pick up a 50lb dumbbell. You're effectively relying only on the muscles in your arm to lift the weight. Now, let's say you're giving your little cousin (who weighs 100lbs) a piggyback ride: you're using your arms, back, torso, legs, and plenty of other muscles in the body to lift your cousin, so you have a lot more strength to draw from. On top of that, the cousin's weight is spread out; no one part of your body is lifting the whole 100lbs by itself, unlike with the dumbbell, whose weight is condensed and only being handled by one arm. ",
"When you lift a person, they instinctively assist you with it. If you have ever had to move a dummy or an unconcious person, that same body seems 10x heavier. "
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87n7pc | why is it that other countries know of american artists and music but in the us we, usually, only know us/uk artists? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/87n7pc/eli5_why_is_it_that_other_countries_know_of/ | {
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"Part of it is, you assume the English language artists are American. They quite commonly are not. \n\nAlso, you're only listening to English language artists, so you don't get the rest of the world in your mix. The rest of the world study English as well as their native language, tho, so what is popular in the us is approachable elsewhere."
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vxifr | dyson sphere | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/vxifr/eli5_dyson_sphere/ | {
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"a dyson sphere is built around a star in order to contain and utilize 100% of the star's energy output, as well as trap curious starships.",
"A dyson sphere is a theoretical device of massive (i.e. planetary) scale. The theory was developed by Freeman Dyson, who suggested that scientists look for evidence of a dyson sphere as an indication of intelligent life. The theory argues that ultimate evolution of a civilization is that they would build their own planet \"around\" a star, instead of colonizing nearby planets. Star Trek: TNG did an episode that featured one, which also included Scotty from TOS. He drank green scotch with Picard. ",
"So as you probably know already, its an enormous spherical structure built around a star. If we assume humans built one around the sun, it would presumably have a diameter equal to the diameter of the Earth's orbit, or a radius of 1AU.\n\nThis leads to two results: first, 100 percent of the sun's energy would fall on the inner surface of the sphere, presumably to be captured and used somehow. That's a really, really huge amount of energy.\n\nSecond, every point on the inside of the sphere would be about the same distance from the sun - and about the same distance we are now, so the entire inner surface could support life, at least in terms of temperature. That's 550 thousand times the surface area of the earth. A really, really huge amount of living space.\n\nAs kareemabduljabbq points out, one theory is that, as this lets a species use all the energy output of their sun, it's kind of the ultimate development in technology. Thus, if you were looking for really, really advanced extraterrestrial civilizations, you could look for the signature of a Dyson Sphere (it would re-radiate solar energy in the infrared spectrum) so astronomers are indeed using infrared satellite telescopes to look for these strong infrared sources. Fermilab has a list of 17 possible sources. They remain unproven (obviously) so far because it's not entirely clear how to distinguish a Dyson Sphere from other natural infrared sources.\n",
"It makes it easier to maneuver around corners or furniture.",
"a lot of people here seem to be referring to a Dyson shell, which Dyson himself admitted to be the least likely type of Dyson sphere. instead a \"bubble\" of non-orbital satellites with solar panels is more realistic, or perhaps a Dyson ring, swarm, or net. a Dyson shell that you could walk on or live on would be dangerously unstable and without some kind of propulsion system it could drift and collide with the sun (that's bad)"
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1ka4rd | what is a jugaloo/jugaloo culture? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1ka4rd/what_is_a_jugaloojugaloo_culture/ | {
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"A Juggalo is a fan of rap-group Insane Clown Posse (ICP) and similar performers. \n\nThese fans tend to be low class, white youth. They wear black and white clown-makeup to shows, drink Faygo (a cheap soda preferred by ICP). There is a tendency in Juggalo culture to be violent with a positive response to anti-intellectualism. This is because members of ICP are High School drop-outs from Detroit - who sold and abused hard drugs in their hay-day. "
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5tzinl | in the usa, considering the emphasis on the separation of legislature, judiciary and executive, why are many judges, including in the federal and supreme courts, appointed by the executive/approved by congress? | Is there not a conflict of interest involved such as if an executive would appoint a judge that has similar ideals over another 'better' candidate?
The whole point of separation of powers, I thought, was to keep each power mutually in check. Having the nominations/appointments decided by the other bodies seems strange to me. Would it make more sense for these things to be decided internally? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5tzinl/eli5_in_the_usa_considering_the_emphasis_on_the/ | {
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"Well the same way, the executive for example is \"checked\" by the judiciary, the judiciary itself is checked by the other two branches in the form of nominations and confirmations.\n\nIf judges were able to appoint themselves, there would be no checks on that branch.",
"The idea is \"checks and balances\".\n\nThe judiciary also needs to be subject to checks or else that would be rule by judges.\n\nAll the branches have some degree of power over each other. These \"competing\" powers is how they keep each other in balance.\n\nHaving one branch wholly independent would allow that branch to overpower the others."
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171tl1 | what are the differences between the european and north-american education systems? | Especially the whole med-school business is extremely confusing. You have to do research in order to get *in* med school? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/171tl1/eli5_what_are_the_differences_between_the/ | {
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"There are 50 countries in Europe, each of which have their own education system developed over decades or often centuries. You might need to be a bit more specific as to which systems you want to compare to the USA."
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29xpk7 | why do allied countries spy on each other? and what kind of information are they looking for? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/29xpk7/eli5_why_do_allied_countries_spy_on_each_other/ | {
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"Spying is used to watch your country's back. When you have hundreds of millions of people's lives riding on your knowledge, it really cannot be justified to not try to get all the information possible.\n\nThere is a lot of information you might want from allies, such as their own motivations for their foreign policy. Perhaps by knowing something your country could position itself to offer a mutually beneficial arrangement, or avoiding putting them in a position where they had to weigh their alliance with you against their own interests. Or maybe it is just the confidence that no shenanigans are going on behind your back.",
"There's a saying in intelligence: *Only your friends can betray you.*\n\nIntelligence agents are paid to be paranoid. They are trying to find out what their friends are going to do before they do it, just like they do with enemy or neutral countries.",
"In addition to what /u/phage0070 said, the \"five eyes\" spy on each other in order to circumvent domestic laws. E.g.: US spies on Canada and provides intel that would be (bureaucratically) difficult or illegal for the Canadian intelligence service to collect. "
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8n3gwf | why is it that we find some repetitive sounds such a raindrops on a tin roof so soothing, yet other repetitive sounds such as snoring or water dripping from a tap, so irritating? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8n3gwf/eli5_why_is_it_that_we_find_some_repetitive/ | {
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"Rain is a constant sound. You don’t hear the individual raindrops pinging from the roof, you hear all 9 billion or so of them at once. It’s like white noise - constant and soothing. \n\nSnoring is an irregular pattern of snorting/snuffling/growling/gurgling. Unpleasant and grating on the nerves. Same thing with a leaky faucet - it’s a repetitive sound that grates on the nerves because our brains are wired to focus on repetitive sounds. It’s distracting and we can’t focus on anything else. ",
"if the noise is constant, our brains learn to tune it out. dripping from a tap is a sound followed by a period of silence. our instincts make it difficult to relax when the noise level keeps changing.",
"White noise is soothing because it soothes you from the earliest time. Inside the womb the outside word is muffled and muddled and the internal sounds of the body add to create a nice white noise that is present until birth essentially. That connection to white noise is carried through. It’s while ppl put white noise machines in infants rooms to help sooth and create stress free environment. The leads to sleep, strengthening the connection between white noise and sleep/soothing.",
"we like sounds or tolerate the ones that sooth us in regard and perception of our entire surroundings. Things like rain, a fan or air conditioning, etc. are good examples of that.\n\nBut snoring and water dripping are not only irregular and obtuse from a constant, environmental sound, they also seem more pronounced and therefore distracting, annoying, etc.",
"Our brains are more sensitive to changes in sound AMPLITUDE than pitch. \"White noise\" is basically sound which has all the same loudness, but lots of different and changing tones. We automatically filter out these noises because they generally represent a constant stimulus and therefore not an important change in our environment.\n\nWhen someone is talking, the volume of their voice changes often, and there are spaces of silence in between. Someone speaking in a monotone is boring, because their voice does not change much in volume, although you can still understand the words they are saying. \n\nWith raindrops or ocean waves, there are small (or at least slow) changes in volume. With dripping water and snoring, there are bigger changes in volume. It goes from loud to silent and back again. For this reason, you can often help yourself fall asleep by \"drowning out\" these stimuli with white noise. Even though it's louder and has more types of sound, it fills in the little gaps of quietness.",
"Pro tip: if you have a dripping faucet, wrap/rubberband a cloth or paper towel around the lip/opening and connect the other end to the bottom of the sink so the water slowly flows down the towel without dripping individually and making that sound.\n\n....maybe do the same for someone snoring\n\nKidding.\n\nMostly...\n\n\n\n...possibly",
"I don’t think the comments attributing it to the consistency and quantity of raindrops are actually covering the larger psychological cause of irritation. \n\nOur brain subconsciously forms context for many of the things we perceive. Although we don’t entirely understand the processes which the brain uses, it is generally understood to be an important part of memory. The brain forms similar patterns of neurons firing in tandem with a specific memory or experience which associate it to previous memories which elicited the same pattern of neurons firing. \n\nThe important thing is that we relate our current experiences constantly to our memories and our memories to our emotions(context); this is a process our brain does automatically and subconsciously. This becomes relevant to dripping water vs rain in that rain is something we are used to, and as a species have been used to for for our entire existence and evolution. Regardless of what the rain is falling on, we know it is rain and have certain brain activity patterns associated with it. \n\nLikewise in the opposite fashion, a leaking faucet, snoring, etc. are commonly associated with negative feelings; a leaky faucet is broken, snoring is unattractive, and so on. It’s not that we are consciously thinking about these things, but our brain will do that subconsciously whether we like it or not. \n\n\nELI5 answer: We know rain is rain and associate it with less negative ideas. A dripping faucet however would be associated with negative thoughts and would therefore more easily elicit negative feelings. ",
"I don't know I have to assume that some people find snoring very soothing or else my dad would not be remarried.",
" Most sounds are repetitive in some way, whether it be frequency or pitch, but rain and fans or other forms of white noise lack most of that repetition. So not only is there no rhythm to speak of in rain, there also isn't a distinct tone to it because it actually covers a large audible range. Because our brains find patterns so easily, any kind of repetition is noticeable to us causing distraction, but the inability to find a pattern means our brains don't focus on it.\n\nThink about it like laying on a bed of nails. When your weight is distributed each point is so minor that you rest on top of it, but take away some of that density and the nails go through you.",
"Did the clock just get louder or did I just notice it?\n\nPlease I must know. ",
"It’s the amygdala- the part of your brain that basically controls your alarm. So if a balloon gets popped behind your head, your amygdala reacts to it. There’s a disorder called misophonia that’s the hatred of sound. People with misophonia have an issue with their amygdala which make it react to sounds like sniffing, breathing, eating, certain letters of the alphabet and more. Basically, think about how infuriating pen clicking is or snoring is and then imagine that it’s like that for many normal sounds. That’s basically misophonia for you except it’s non-stop and constant, which is why it’s an issue. Your amygdala tries to determine what sounds could be dangerous and sets off your “alarm,” which is basically like a jump scare in a way.\n\nTLDR; your amygdala messes with you and sets off your alarm for random sounds like snoring. ",
"I have always thought that rain only sounds soothing when you aren't getting soaked by it. The sound of rain accompanying staying dry might just be a combination that evolution has deemed rewarding and thus relaxing. ",
"This is something in the brain that occurs to prevent sensory overload.\n\nIt's called Sensory Gating. \n\nThere is a frequency of time that your brain \"gates\" out to prevent your mind from being overloaded.\n\nNicotine strangely has an effect on this and helps people from getting sensory overload.\n\nPeople with schizophrenia and autism are both noted to have issues with this. Their gating doesn't function as well as others. \n\n_URL_0_\n\nELI5 : Your brain takes noise that is fast and repetitive and blocks part of it out. If the noise is slow and repetitive you hear it normally. Nicotine enhances our ability to be less bothered by it. ",
"What about a ticking clock while you are trying to go to sleep? Like, a ticking clock that is in the other room so you can barely hear it so you try really hard to hear it to make sure you can’t hear then you concentrate so hard you hear it but then you can’t stop hearing it and you can’t sleep so eventually you get up and take it off the wall and hide it under a pile of blankets and you finally sleep but in the morning your buddies mom is like, “why is my clock off the wall and hidden underneath a mound of blankets and pillows?” So you play dumb and then she’s like “...and why are the batteries out of it as well?” And then you feel really dumb because you took the batteries out but then muffled the inoperable clock anyways. ",
"Probably because you've never played basketball in a wood shop with a tin roof in a downpour.\n\nWe had to quit playing. It was deafening. ",
"Am I the only one who finds snoring kinda soothing in a way? I can fall asleep to it perfectly fine. I feel like I need it to sleep at times",
"A six foot water fountain on the other side of a 6 foot wall drives me crazy. There is nothing soothing about the sound that carries over the wall. Can anyone explain why? Advertisers are constantly saying how soothing water fountains are.\n\nAlso, why are low frequency monotone sounds so irritating and go right through walls and doors - no way to block it out.",
"Am i the only one that loves the sound of black shoes tapping on any surface? Especially the one's with heels!",
"Man as soon as I read snoring I threw my phone at the wall. You were right about the irritating part. Now where did I put that falling rain CD?",
"Can anyone ELI5 why some people like me do, in fact, find even constant noises like white noise machines or rain irritating and cannot sleep without absolute silence. What happened to my mind's tuning it out ability?",
"Can confirm. Student was clicking pen for a good hour yesterday and I had to refrain from throwing him across the class... Am not a student. Administration frowns on that here. ",
"i think it boils down to sound frequency (wave lenghts). The more constant, the more soothing. While longer frequencies tend to be disturbing.",
"I'm going to disagree with these other posts and say that a huge element is where you focus your mind and thoughts. You can improve control over what you mentally focus on, with practice. A tap dripping, people talking, a fan blowing...these can all be ignorable background noises if you will it. It's a matter of letting yourself notice the noise, or directing your attention to something else. \n\nA great example is TV and film mixing. There are tons of background noises added in to every scene, and you don't typically think about them because you're not supposed to. You're supposed to focus on the dialog, so you do. Even when there's no dialog, you're thinking about what you're seeing, not what you're hearing, so you shove all those sounds to the back of your mind. ",
"This could be bullshit but I remember reading once that people love staring into a fire so much because it's a chaotic system that your brain is trying to make sense of or fit a pattern to, so you kind of get lost in a trance, maybe rain has a similar effect. A drip on the other hand repeatedly grabs your attention, like archer 'lana, lana, Lana, Lana! LANNAAA' and so is the opposite of relaxing.",
"Well, snoring at least is no longer irritating.\n\nMy wife snores and when we first married it was a thing for awhile.\n\nNow, after nearly 20 years and both of us well into our 40s, it makes me feel good because i know she's alive (she's a silent sleeper when she's not snoring and it freaks me out).",
"Most likely the constant cadence of a single drip is not something your brain can ignore as white noise. A single noise is danger, while constant noise is safe. A drip is single noise, wake, panic, danger, oh false alarm, go back to rest. Next drip. Repeat cycle until brain is tired of false positives, and stays alert (and now you are pissed off) \n"
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"https://en.wikipedia.org/wiki/Sensory_gating"
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||
jcxz0 | explain the slashed number on an ip address (ex:100.23.16.0/24) | What does the slashed number (/24 in 100.23.16.0/24) mean? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/jcxz0/explain_the_slashed_number_on_an_ip_address/ | {
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"This is called CIDR notation. \n\nIP addresses are made up of two components joined together: the network address and the host address. \n\nThe slash on the end is used to denote the size (in bits) of the network portion of the address. \n\nAllow me to explain further. \n\nTake the address 192.168.0.0/**24**. In this instance, **24** bits (3 bytes: the 192.168.0) make up the network address, and the remaining 8 bits (1 byte: the final 0) make up the host address. \n\nWhat this means: \n\nWhen one computer sends data to another computer, it has to know how to get that data there. When the receiving computer is on the same network (for instance, plugged into the same network switch), all the sender has to do is throw the data out on the wire, and the receiver will see it. It's like talking to someone in the same room - you just talk, and they can hear you. \n\nHowever, if the receiver is on a different network - whether on the other side of the planet, in the next department, or whatever - that approach isn't going to work. You can't have one big room with everyone in it - your voice wouldn't carry, and you'd never be able to hear anyone over all the babble. So instead, the internet is divided up into zillions of separate network, each with a maximum number of hosts in each. \n\nIn the case of 192.168.0.0/24, the 1-byte host address can be anything from 0 to 255, so you've got a maximum of 256 possible host addresses, and a corresponding 256 hosts in the local network. \n\n(actually, 254. because .0 and .255 are reserved, but let's not split hairs)\n\nNow, if you want to talk to someone in another room, what do you do? You talk into the phone, of course. And in the case of networking, it's much the same. Instead of trying to send data to the receiver directly, the sender addresses the data to the network's router, which forwards it on to the correct network (or at least to the next router along the way).\n\nIn order to know which hosts can be reached directly, and which ones need to be reached through a router, the sender compares the two addresses, and considers the subnet size. \n\nFor instance, 192.168.0.1 wants to talk to 192.168.0.3. It's been told it lives on a /24 network, so it compares the first 24 bits: 192.168.0 and 192.168.0. They're the same, so it can just send locally. \n\nBut suppose it wants to talk to 192.168.1.12 - now it compares 192.168.0 and 192.168.1, and they're different. So instead, it sends the data to the router (also known as the *default gateway*), which will forward it on to 192.168.1-land, where the receiver will be able to see it. \n\nCIDR notation is just the inverse of the \"subnet mask\" used when setting an IP address - the subnet mask is a 32-bit number with 1s for the network portion. So a 24-bit subnet mask would thus be 255.255.255.0 - 24 bits of 1s, followed by 8 bits of 0s. \n\n",
"This is called CIDR notation. \n\nIP addresses are made up of two components joined together: the network address and the host address. \n\nThe slash on the end is used to denote the size (in bits) of the network portion of the address. \n\nAllow me to explain further. \n\nTake the address 192.168.0.0/**24**. In this instance, **24** bits (3 bytes: the 192.168.0) make up the network address, and the remaining 8 bits (1 byte: the final 0) make up the host address. \n\nWhat this means: \n\nWhen one computer sends data to another computer, it has to know how to get that data there. When the receiving computer is on the same network (for instance, plugged into the same network switch), all the sender has to do is throw the data out on the wire, and the receiver will see it. It's like talking to someone in the same room - you just talk, and they can hear you. \n\nHowever, if the receiver is on a different network - whether on the other side of the planet, in the next department, or whatever - that approach isn't going to work. You can't have one big room with everyone in it - your voice wouldn't carry, and you'd never be able to hear anyone over all the babble. So instead, the internet is divided up into zillions of separate network, each with a maximum number of hosts in each. \n\nIn the case of 192.168.0.0/24, the 1-byte host address can be anything from 0 to 255, so you've got a maximum of 256 possible host addresses, and a corresponding 256 hosts in the local network. \n\n(actually, 254. because .0 and .255 are reserved, but let's not split hairs)\n\nNow, if you want to talk to someone in another room, what do you do? You talk into the phone, of course. And in the case of networking, it's much the same. Instead of trying to send data to the receiver directly, the sender addresses the data to the network's router, which forwards it on to the correct network (or at least to the next router along the way).\n\nIn order to know which hosts can be reached directly, and which ones need to be reached through a router, the sender compares the two addresses, and considers the subnet size. \n\nFor instance, 192.168.0.1 wants to talk to 192.168.0.3. It's been told it lives on a /24 network, so it compares the first 24 bits: 192.168.0 and 192.168.0. They're the same, so it can just send locally. \n\nBut suppose it wants to talk to 192.168.1.12 - now it compares 192.168.0 and 192.168.1, and they're different. So instead, it sends the data to the router (also known as the *default gateway*), which will forward it on to 192.168.1-land, where the receiver will be able to see it. \n\nCIDR notation is just the inverse of the \"subnet mask\" used when setting an IP address - the subnet mask is a 32-bit number with 1s for the network portion. So a 24-bit subnet mask would thus be 255.255.255.0 - 24 bits of 1s, followed by 8 bits of 0s. \n\n"
]
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[],
[]
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|
fl7tf5 | why do higher end vehicles tend to have their car models named after numbers? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fl7tf5/eli5_why_do_higher_end_vehicles_tend_to_have/ | {
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"Some car makers rely on the strength of their name while others rely on the strength of their models names. For example, people are more apt to take pride in saying they drive a Mustang or a Corvette rather than say they drive a Ford or a Chevrolet. Other companies don’t need the model name recognition - if you drive a Lexus that is enough. Lamborghini is an example of a company that uses model names like Gallardo and Murcielago but at the end of day people just recognize it as a Lambo.",
"You mean like this one? \n [_URL_0_](_URL_1_)",
"Two reasons:\n\n1. Using alpha-numerics, you can create a code that clearly informs the customer base where a model falls in the range (IE, a BMW 340 is \"below\" a BMW 540). It can also communicate characteristics - different ways of showing SUV vs Sports vs Sedan, engine sizes, stretch or standard length, etc.\n2. Translation is easy. Names are very hard to translate into world languages if you are a global brand, instead you can just numeric everything and be done with it. Brands that name cars have to be careful when translating those names into other languages and usually they come up with whole new names or even brands.",
"Also the number can sometimes refer to the engine\nsize, at least in BMW, Mercedes and several others.\nIn a BMW 540 the 40 stands for 4.0 litre V8. In a 525 that would be a 2.5 litre straight six.",
"I dont have personal expertise in this field in any way, but I have heard this is an example of car companies conforming to modern marketing strategies. For newer vehicles, there is a tendency for automakers to name their premium lines something \"meaningless\" like a stream of numbers with a letter tracked on the end so that the model will be associated with the brand. In the case of their economy models they will give the car a name people will remember and say so it will be associated only with itself and not the brand.",
"Me: \"get the ball, it's next to the 240sx!\"\n\nFriends: \"what?!\"\n\nMe: \"the nissan over there.\"\n\nFriends: \" the purple car?\"\n\nMe: \"yes, the purple car...\""
]
} | [] | [] | [
[],
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"https://en.wikipedia.org/wiki/Fiat\\_Uno",
"https://en.wikipedia.org/wiki/Fiat_Uno"
],
[],
[],
[],
[]
] |
||
3paiv1 | is there any "ultimate" security clearance that gives you access to anything the government does if you ask? | Either legally, or technically illegally but noone would deny you if you showed up and demanded to know? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3paiv1/eli5_is_there_any_ultimate_security_clearance/ | {
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"I'm going to go out and say if any such thing does exist then there is absolutely no way you're going to find out about it. If someone has that much clearance, that much power, then you're getting into conspiracy theory level stuff and need a conspiracy explanation.",
"No, having a secret clearance doesn't entitle you to see everything that is classified secret; the same goes for top secret. You also have to have a need to know the information. For example, a janitor at the NSA must have the level of clearance required to enter any room he/she enters but cannot demand to see anything classified.",
"My previous security clearance was DPA:SC (British security \"secret\" level clearance) The wording of the clearance was for \"unrestricted\" access to secret and \"as required\" access to top secret. But all this means is that I cannot be prosecuted for having read anything marked as secret that was related to my work, or anything that my work *required* me to access marked as top secret. But this does not mean that I could request anything I felt like and read it out of boredom. Even if I requested information with a public classification it could still be denied. \n\nYour clearance level is just a safety guideline, but you still need to be \"read in\" for any specific information that you need. But it is not all encompassing, so in theory you could be arrested for having a copy of the snowdon leaked documents even if your security clearance covers everything in it."
]
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|
cv5eks | what is the difference between an estate vs trust | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cv5eks/eli5_what_is_the_difference_between_an_estate_vs/ | {
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"text": [
"An estate is the totality of a deceased person’s property, which is (eventually) transferred to his heirs. A trust is a legal instrument by which a (living) person gives some of his property to a new legal entity (the trust) to hold, which has rules about who gets the property when the person (called the grantor) dies. An estate must go through a regulated process (called probate) between when the descendant dies and when the money or other property is distributed, and this can take a long time. Whereas a trust, the property is already there, so when the decedent dies, the trust is already operating according to the decadent's wishes, and it just keeps operating, but the money in it is immediately available to the heirs, if that’s how the grantor wanted it to be. Also, some kinds of trusts avoid certain taxes.",
"An estate is a dummy that stands in for a dead person who recently died. They own whatever the dead person owned the last second they were alive. Someone alive is then named executor, meaning they have to do what the will says. If there is no will or someone fights the will, the executor does what the court decides is fair. When all property has been given away, the estate stops existing.\n\nA trust is a dummy that stands in for a living person until soon after they die. That person, the administrator, can give the trust stuff and money. Someone else, the trustee, must take care and hold onto the trust for someone else, the beneficiary, to get when the administrator dies. The trustee must be paid from the trust to do this. If it gets too expensive to maintain, it can end sooner. In any case, it stops existing when it has no more stuff.\n\nAnything in a trust isn't part of that person's estate. When the administrator dies, the trust gives out its stuff to the beneficiary. No questions asked, no challenges allowed. The estate has to wait for a judge to tell it who gets what before it gives the stuff away."
]
} | [] | [] | [
[],
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] |
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