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1mxbqy | what exactly does the nucleolus do in a cell? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1mxbqy/eli5what_exactly_does_the_nucleolus_do_in_a_cell/ | {
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"I could tell you, but seriously, play this video game. It's called \"Cellcraft\" and it will do a better job of teaching you about how cells work than any textbook I've ever come across.\n\n_URL_0_"
]
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"http://www.kongregate.com/games/CellCraft/cellcraft"
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fw7x1q | why does a boat need a rudder to turn, while a surfboard, skimboard, and etc. don’t? | As a surfer, I feel like it could not just help me understand the technique, but I think it would be cool to know the mechanics behind it. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fw7x1q/eli5_why_does_a_boat_need_a_rudder_to_turn_while/ | {
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"Rudders change drag in the water, forcing the boat to change direction (because water is now hitting the rudder more on one side when turning).\n\nSurfers achieve the same result by directly tilting the board with their weight.\n\nCan't easily tilt an entire boat.",
"Surfboard fins serve the same purpose as rudders.\n\nAs for skimboards, tr14l is correct: tilting the board with ones weight is what helps steer the board.",
"Because Surfboards and Skimboards weigh less than the rider.\n\n\nBoats weigh more, which means the rider can't use his weight to move them."
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45n7vf | how does the possible equality of p = np allow us to solve some currently unsolved problems? surely knowing that there's a simple solution doesn't mean we are gonna find it, right? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/45n7vf/eli5_how_does_the_possible_equality_of_p_np_allow/ | {
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" > How does the possible equality of P = NP allow us to solve some currently unsolved problems? \n\nIt wouldn't. The problems in this domain are solvable, but there is currently no know way to solve them quickly.\n\n > Surely KNOWING that there's a simple solution doesn't mean we are gonna find it, right?\n\nThe most common way to prove something exists in mathematics to find an example of that something...this is called a constructive proof.\n\nSo while it is possible it could be proven indirectly, the most likely way P = NP would be proven would be by producing an algorithm that computed NP complete problems \"quickly\"."
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9fgxje | how does a river maintain such a large size from such a small stream? | This might be a stupid question but It was on my mind yesterday. So the river stream is only a small narrow bit of water. If you go to the widest and deepest part of the river further down how does it reach that level and furthermore how does it maintain it from such a small source? Is it something to do with how fast it flows the further up you go? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9fgxje/eli5_how_does_a_river_maintain_such_a_large_size/ | {
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"Water will always flow downhill to the lowest point. That's physics, thank you force of gravity. \n\nThe Earth is not flat, therefore all water will search for the lowest point. \n\nA stream comes up out of the ground on a mountain. It trickles down the mountain until it merges with another stream coming down off a different mountain or area, but who's water is also seeking the lowest point. The two streams merge, forming a new stream with double the volume (probably not but for the sake of the example). \n\nThis keeps happening again and again until you get a river. As for the depth and such, well that much water is a force unto it's own. It literally cuts through rocks and carves out Grand Canyons over time. When you've got that much of it, it's pretty easy to make a river. \n\nYou should watch YouTube videos of the Okavango Delta (sp?) Basically it's an area of the world that's so dry and flat, that once a year the rainy season from up North washes all the water down south, where it pools. \n\nIt is literally just a yearly puddle that forms. An enormous thousand kilometer puddle. That's all it is. But it's one of the most biodiverse places on Earth. It's wild. \n\nEdit: and here you go \n\n_URL_0_\n",
"The river gets larger every time a smaller stream flows into it. By convention, the \"river\" is the larger branch at every junction, but its kind of arbitrary, because usually big rivers are fed by lots of smaller ones of about the same size, and don't have a single \"source\".\n\n[Example](_URL_0_)"
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6pzmsq | why do very small amounts of elements such as arsenic and toxins such as botulinum toxin have such deadly effects. is it some type of crazy chain reaction? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6pzmsq/eli5_why_do_very_small_amounts_of_elements_such/ | {
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"Yer not alone in askin', and kind strangers have explained:\n\n1. [ELI5: How can such a tiny amount of poison kill someone? ](_URL_2_)\n1. [ELI5: How can a seemingly small amount of poison or venom be so eefective. 100 mg of venom from a Black Mamba snake is enough to kill a 100kg adult human. How is this possible? ](_URL_0_)\n1. [ELI5: How can something as tiny as a pill or a few drops of poison affect a full-grown adult so much? ](_URL_3_)\n1. [freenarative comments on ELI5](_URL_1_)\n"
]
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"https://www.reddit.com/r/explainlikeimfive/comments/3igkl5/eli5_how_can_a_seemingly_small_amount_of_poison/",
"https://www.reddit.com/r/explainlikeimfive/comments/4680ke/eli5_how_can_something_as_tiny_as_a_pill_or_a_few/d03htvi/",
"https://www.reddit.com/r/explainlikeimfive/comments/3nol1y/eli5_how_c... | ||
4mnm3b | how do freeware companies like mozilla or opera max stay in business? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4mnm3b/eli5_how_do_freeware_companies_like_mozilla_or/ | {
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"These questions are easily answered by looking at the company in question's website. \n\nFirefox is mostly sponsored by Netscape, but has other sources of income. You know how Google is the default search engine? Google pays (a lot) for that. \n\nOpera, too, is funded by an independent company that sells other products, and Opera itself does more than just make a browser. They also sell commercial software. \n\nYou will find that, in many cases, the freeware software is just a small part of what a company does, and may be considered a loss-leader. \n\nBy the way, Google doesn't \"own\" an ad company. It pretty much *is* an ad company. It owns everything else. ",
"Mozilla and Google and Opera are big enough that they do rely on some sort of funding, but it is perhaps a bit cynical to say \"everything that's free gets paid for somehow\" here.\n\nSometimes people just write and release software out of the goodness of their hearts.\n\nMaybe they'll get a grant from Google or something, but there is no guarantee that any given piece of free software - this especially applies to smaller projects - actually does create any very clear return on time investment for the creators."
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5m2zcx | why are some video games or updates released with major problems instead of being delayed? | Even with a deadline, surely they would understand that releasing what they've got will only hurt, no? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5m2zcx/eli5_why_are_some_video_games_or_updates_released/ | {
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"Money.\n\nThey need the income to fund the continued development of the game. This is a practice that software developers have been using for a very long time. It is not just games either but OS and network gear. They all do some amount of 'sell to fund' and it doesn't seem to hurt them because people still are buying.",
" > ...releasing what they've got will only hurt, no?\n\nNo.\n\nOn Christmas Day that kid needs to be glued to *your* game come hell or high water. Doesn't matter if it doesn't work. Doesn't matter if the console is made out of wood and bailing wire.\n\nA good plan today is better than a perfect plan tomorrow.\n",
"Let's say your boss gives you an assignment you need to get done by Friday. Thursday comes, and you know that it won't be done - you go to your boss and explain, but they insist that they need whatever you've got by Friday, because your assignment needs to go out to partner companies and other branches due to agreements and contracts.\n\nIt works the same largely with games. For an example, let's go with Dragon Age 2. The game is *developed* by BioWare, but *published* by EA. EA is the \"boss\" in this scenario - they told BioWare, the \"employee,\" that they needed the game done by a certain release date. This is due to contracts with retail stores, advertisers, partners, etc. Despite the fact that the game was released with many flaws and a lot had to be cut, they had a strict deadline they had to meet, or the team could potentially be fired. The other reasons for set release dates can vary. They might want to get in the holiday rush, compete with a new console release as a sort of package deal, be bound by an exclusivity contract with a certain platform, or want to avoid crashing into other games they're developing (if a company has two blockbuster titles, it's better to release them apart than to have them both come out at once and have their audience split between them). If it's an online game, things like servers might come into play - you're paying for the server from a certain date, and if the game isn't out you're just throwing the money away.\n\nIn certain very egregious examples, or if the developer and publisher are on good terms or are close enough, you might get a delay instead. If a game literally just will not work, they can delay it. Or if you have a smaller publisher that works more closely, they might understand. But the AAA companies tend to want what they want when they want it - and they have so much clout and name recognition that people will go out and buy it no matter how broken it is."
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1fq5x7 | what would happen if we stopped social security today? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1fq5x7/what_would_happen_if_we_stopped_social_security/ | {
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"There'd be no more money coming in to pay retirement, widow/widower and disability benefits to millions of people who may depend on SS to survive, so there would probably be a big increase in poverty. SS is a pay-as-you-go system, so current revenue funds current benefits.\n\n\nIt's difficult to predict how this would play out in the real world, but it's certain that charities would be overrun with requests from people who are unable to work for health reasons or who are too old for work, and this would probably overwhelm other parts of the welfare system as well.",
"Old people riots.",
"Instant Recession or Depression. [Per the SSA](_URL_0_), $821 Billion goes out each year. Almost all of this money is spent on consumer goods and utilities as fast as it's dispensed. Money in immediate circulation (think stimulus) drives consumption and employment. Regardless of where on the economic scale the recipient is, most of that cash rolls right back into the economy.\n\nSo, even if Gramps has enough alternate funding to pay the electric bill, he might not have enough to take Gramma out to Denny's or get little Tommy a colorful piece of plastic for Christmas. Or buy a new Buick. Or lend Susie the mortgage down payment she'll never repay him. Or have an addition built on the garage. And all the folks who would have done that work, provided that service or sold those items would be hosed.\n\nOr...they might not have adequate alternate funding, and they're the \"new poor.\"\n\nThe system sucks. Most alternatives suck more. IMO."
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6r025t | if you leave an appliance, lamp, charger, etc, plugged into the wall when not in use, does this eat electricity and run up your electric bill? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6r025t/eli5_if_you_leave_an_appliance_lamp_charger_etc/ | {
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"Depends on the device, for a cell phone charger, yes. The older ones use to use quite a bit of power when no phone was connected. Newer ones turn off 99% of their stuff when there is no phone, but they still consume something.\n\nAs for the other things, well it depends, but stuff like a cheap toaster, no, it contains a physical switch, and has exactly two states, on and off, when off the power is physically disconnected and it uses zero power. Many appliances with physical switches are similar (microwaves, washers, dryers, etc), they might have an on switch with a spring powered timer, and when off physically disconnect power. The modern ones have fancy screens, touch buttons, clocks, wifi, whatever, that stuff stays on when it's off."
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9ortzb | how does penicillin work, why is it so effective, and will it work forever? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9ortzb/eli5_how_does_penicillin_work_why_is_it_so/ | {
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"Penicillin disrupts the cell walls of certain bacteria causing them to die, not all bacteria are vulnerable to it and the more often bacteria are exposed to penicillin and survive the more likely they are to become resistant to it. For more details - _URL_0_",
"Penicillin is already becoming way less effective then when it was discovered because the bacteria that doesn’t die and is immune survives and spreads creating an immune strain ",
"Penicillin won’t work forever, and had already stopped working in many cases. Antibiotic resistance is becoming a serious problem. Bacteria are evolving to be impervious to antibiotics. With penicillin being the oldest one, it’s had the longest time for bacteria to become resistant to it. So it doesn’t work for a lot of things now. Fortunately there are other antibiotics that will work. But there are some bacteria that are resistant to all bacteria, and people die of that every day. ",
"Penicillins are a group of compounds that are produced by the mold *Pennicillium chrysogenum.* as well as some related species.\n\nPenicillins work by blocking a key enzyme that bacteria use to repair, remodel and expand their cell walls. This causes defects in the cell wall to accumulate and causes the cell wall to rupture. In some bacteria this may not be immediately fatal, but it weakens them against attack by the immune system.\n\nIt is effective because a large number of bacteria have cell walls of similar composition and require a similar enzyme to perform repairs and growth. Bacterial cell walls are their first line of defense against hostile environmental conditions. \n\nHowever, the more that penicillins are used, the more *selection pressure* there is for Drug Resistance. This is just the same as going through a bag of beans, picking out the beans that are yellow colored, planting those next season, and feeding the rest to pigs. \n\nIt's safe to say that a good portion most of next year's crop will be yellow. If you do this over three years of crops, pretty soon your whole crop will be yellow.\n\nThis is an unfortunate side effects of widespread use of antibiotics. This will always also work to breed for organisms that are resistant. \n\nBacteria can develop resistance to penicillins in three common ways. Bacteria have *pore proteins* in their surface that allow desirable molecules like nutrients to enter the cell. But penicillins are small enough that they can pass through too.\n\nSo changes in the protein can limit the ability for penicillin to enter the cell, and do it's work. \n\nThis is like making the doors and windows on a fortress smaller so enemy soldiers can't sneak through. \n\nThe second is to change the target molecules in such a way that penicillin can no longer fit in the active site on the enzyme.\n\nThis is like preventing people from stealing custom wheels and tires on your car, by using lug nuts with an unusual shape, that can't be gripped with normal wrenches. \n\nThe third mechanism is the most impressive. That is, modify enzymes the bacteria uses to detoxify certain compounds, to target penicillin and break it down into a harmless form. These are known as Beta-lactamase enzymes. This s like creating heat seeking missiles that will seek out and destroy incoming aircraft.\n\nNote that *Pennicillium* molds have been around a long time and bacteria have had a long time to develop countermeasures to them. \n"
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26mdkw | where does sound go when it fades? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/26mdkw/eli5_where_does_sound_go_when_it_fades/ | {
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"Sound is energy in the form of compression waves through the air. Any time the waves hit something, they absorb some of the energy and reflect some of it. Eventually, all the energy is absorbed into the environment.",
"The best way to visualize a sound wave is by comparing it to a the [waves formed when something is dropped into water](_URL_0_).\n\nA higher or taller wave is the equivalent of the sound being louder. As the water/sound wave gets further from the source, it spreads out more and beings shorter/quieter. The sound doesn't disappear, it just spreads out further and further until it becomes unnoticeable.\n\nIn some cases, the sound waves may also be absorbed by another material, such as a soft carpet or dirt, and in other cases they may be reflected (echos). These would look very similar to waves being absorbed by/reflecting in water.",
"it is turned into heat. \n\nout past a certain distance, the very tiny friction force between the molecules in the gas is enough to be larger than the amount of force exerted by the wave once it spreads itself thin enough.\n\nedit: spelling/grammar. stupid phones"
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18l18j | hair color. | What is it that makes people have different colored hair? And why is it that peoples natural hair color can't be all different colors? Why isn't the color blue a natural hair color? Or green or any other color, why is it limited to white, black, brown, red, and blond? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/18l18j/eli5_hair_color/ | {
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"Humans can only make one color pigment: brown. It is what makes freckles, skin coloration, and hair color. All hair colors come from different levels of the same pigment."
]
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9qgyry | the difference between first past the post vs proportional representation systems | I've read up on it but it just muddles my brain. I'd greatly appreciate it if someone could explain using simple terms involving chicken nuggets or something. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9qgyry/eli5_the_difference_between_first_past_the_post/ | {
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"First past the post means that the winner of a contest gets all the chicken nuggets. Proportional representation means that the winner simply has more chicken nuggets than anyone else in the contest.",
"There are some great videos on a bunch of systems perfectly explained by CGP grey\n\n_URL_0_\n\nCheck out some of the others he explains too",
"First past the post: the country is divided into a number of regions equal to seats in Parliament. In each region, one specific person is elected to represent that region in Parliament. There is usually one candidate per political party. Whoever gets the highest number of votes among the voters in that particular region, gets the Parliament seat.\n\nProportional representation: the country is split into large areas, and each area is assigned a certain number of seats in Parliament. (Or even the entire country is one big region.) A whole bunch of people compete within the region, and they are arranged in lists. (Each list usually represents a political party.) All the votes in the region are counted, and the votes for each list are summed up. Then the total number of Parliament seats for the region are distributed among the lists **in proportion** to what percentage of the total votes each list got. For each list, they give the Parliament seats to either the people at the top of the list, or the people within the list who got the most individual votes (depends on the country's laws).",
"Imagine you and your friends (Alice, Bob, Charlie, Diana, Erin) live in the suburbs and there's no food in the house. You decide to get food delivered, but naturally you don't want to pay for delivery from multiple different places. So you get together and vote on what restaurant you want, and whatever place gets the most votes wins. Say Alice and Bob vote for chicken nuggets, Charlie votes for pizza, Diana votes for Chinese, and Erin votes for sushi - the result is everybody eats chicken nuggets, even though only 40% of the house voted for it! This is first past the post - whatever option gets the most votes wins.\n\nNow imagine instead of being at home, you're all at the food court in a mall. The voting goes the same way, but instead of needing to pick one option, everybody can go to the place they want and still eat together! This is proportional representation - the goal is for the representatives of the district reflect the distribution of voters.\n\nYou'll notice that to do proportional voting, you need to be able to elect **multiple representatives for any district**. If you're switching from first past the post system like in the United States, that means you'd need to either expand the legislature or draw bigger districts. For example, in Ireland, districts are represented by 3-5 members."
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2955gm | the difference between scientific theory, hypothesis and colloquial theory... | My understanding is that there are three words that often get used interchangeably but are often used incorrectly. For this reason I try and stay away from using any of them!
There's theory in the usual sense (*my theory is that Tom is tapping Erin, but i'm not sure*)
Theory in the scientific sense (The theory of evolution)
And hypothesis... which i've only ever heard in a scientific setting. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2955gm/eli5_the_difference_between_scientific_theory/ | {
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"**A *scientific theory* is a substantiated and testable explanation for a variety of observations and facts**; it also makes predictions about the future. It is often modified to reconcile new facts, but it can also become obsolete when a new scientific theory is proposed that can explain more observations and facts than the previous one.\n\n**A *hypothesis* is a testable, reproducible and falsifiable statement that has to be refuted by experiments and/or observations**. In other words, one must be able to test it multiple times and see if it is false. If it turns out that the hypothesis is true (e.g. \"phenomenon X is correlated with phenomenon Y\"), then it can be extended (e.g. \"Is phenomenon X correlated with phenomenon Z?\") and/or inserted into the relevant scientific theory.\n\n**A *theory* in everyday use is a guess, conjecture.**"
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3mru23 | will earth's population continue to grow at the rate it has over the last 40 years? or will we start dieing off faster due to overcrowding? | The earth's population has about doubled in the past 50 years or so... will this trend continue? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3mru23/eli5_will_earths_population_continue_to_grow_at/ | {
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"Probably not.\n\nAs populations become more affluent they have fewer children. Basically because when you work in an office and live in a developed country you don't need to have 17 kids because half will die of polio and the other half have to milk the goats.",
"Nope. In fact the rate of global growth has been dropping fairly steadily over the last 20 years. As more countries become affluent their birth rates drop and we will eventually reach a stable point where population stabilizes or even declines. "
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3bn2ex | why are checks still in use? it seems horribly insecure, seeing as you only need the numbers on the check itself to withdraw money from the account. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3bn2ex/eli5_why_are_checks_still_in_use_it_seems/ | {
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"Some people want proof of payment. This is far more easily attainable from a cancelled check than hoping to get a credit card statement, which does not always clearly show the entity who was paid. ",
"Think about it systematically. I have money in my bank account and I want to give it to put it into someone else's bank account.\n\nWhat information is needed to do this:\n\n1. My account number (not just my name as the money can't go into the wrong account).\n2. Some kind of verification/security check that the transaction is authorized.\n3. The amount of the transfer.\n4. Information to identify to whom the money goes (we can talk about this later).\n\nNow a cheque contains all four of those things. The signature/holograms on the cheque are the security feature. \n\nIf we wanted to get around providing someone else our account number we would need to set up the transfer directly with out banks. That means calling in (unsecure), or attending in person (inconvienient), or faxing/emailing in some kind of form (which aside from difficulty finding the account number to draw from would be no more secure than a physical cheque).\n\nThe problem however is that any of the above require us to know the account number the money is going into. Instead of us giving someone else our account number, they have to give theirs to us. You can't just say \"Hello Bank of America please give john smith a million dollars from my account\". John smith on the other hand can take your cheque and deposit it into his account. As long as the names match the onus is on the depositer to put it into the correct account.\n\nEver try and do a wire transfer? Much bigger pain in the ass than just writing a cheque. Even those email money transfer apps. If I had a cheque on me it would be faster to write it out than transfer money that way."
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7d3ytd | what's the difference between a serial killer and a mass murderer legally or in the media? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7d3ytd/eli5_whats_the_difference_between_a_serial_killer/ | {
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"These are not legal categories.\n\nMedia-wise, a serial killer kills on several different occasions, widely separated in time; a mass murderer kills numerous people on one day.\n\nAlso, this usually implies a serial killer must work hard to avoid detection and capture, while a mass murderer risks being caught or killed on-the-spot, and many are even suicidal.",
"For the most part these are not really legally defined concepts. They are mostly classifications and subject to some discussion.\n\nThere was one attempt to legally define a serial killer, which was in the *Protection of Children from Sexual Predator Act of 1998 (Title 18, United States Code, Chapter 51, and Section 1111)*. This gives the definition:\n\n > The term ‘serial killings’ means a series of three or more killings, not less than one of which was committed within the United States, having common characteristics such as to suggest the reasonable possibility that the crimes were committed by the same actor or actors.\n\nThat definition was fairly limited in application and was mostly for establishing when the FBI could assist local law enforcement. \n\n\nAgain, for the most part these are classifications which get used by law enforcement, the media, and other people that like to talk about crime and can be subject to a lot of discussion. The common list for differentiating between a serial killer and a mass murderer is \n\n- one or more offenders\n\n- two or more murdered victims\n\n- incidents should be occurring in separate events, at different times\n\n- the time period between murders separates serial murder from mass murder\n\nOr roughly speaking it's mass murderer (someone who kills several people in a single event in a single location) vs spree killer (someone who kills several people in a single event but in different locations) vs serial killer (someone who kills several people at different occasions) "
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7tenvh | if some english words like hit, put, etc, have no different version of past tense, why every other word has to? | if its understandable to talk about having put something in the past, without a different word than the present tense, isnt any other past tense useless, since they all can be understood anyways? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7tenvh/eli5_if_some_english_words_like_hit_put_etc_have/ | {
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"English is legendary for its tendency to \"acquire\" words from other languages, and the rules that apply to some do not always apply to others. English is an inconsistent, bizarre, organic mutant of a language, flexible and creative, and indifferent to your arbitrary \"rules\", man. "
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3mj3fj | what causes a smoke ring in bbq? | I'm referring to the ring of pink meat just under the bark on bbq'ed meats like ribs, brisket, etc. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3mj3fj/eli5_what_causes_a_smoke_ring_in_bbq/ | {
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"When wood or wood chips are burned in the BBQ or wood smoker, the two gasses nitric oxide (NO) and carbon monoxide (CO) are produced. These gasses react with the iron that is in the myoglobin, preventing it from turning colour. Myoglobin is a substance in the muscle fibers that stores and transfers oxygen and gives raw meat its pinkish colour. As meat cooks it turns from pink to brown as the myoglobin breaks down from the heat, but where NO and CO have fixed the iron in the myoglobin it remains pink. \n\nThe pink forms in a ring shape because before the NO and CO can penetrate very deep into the meat it has become hot enough to turn brown, so it is only pink near the surface, where the gasses have been able to reach.\n\n[More details](_URL_0_)"
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aqh4st | if i clench my teeth hard enough could they break? if not, why? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/aqh4st/eli5_if_i_clench_my_teeth_hard_enough_could_they/ | {
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"Your jaw is quite likely strong enough to break your teeth, but you probably won't ever clench with maximum force. ",
"Son of a dentist here.\n\nYes your jaws are strong enough to break or crack or chip your teeth however when just clenching you rarely use that much force but it can happen. \n\nYou can also crack or break your teeth if you eat something hard like a really hard piece of candy. When eating we usually use more force than when just clenching and thus the risk is higher. Eating a piece of hard candy also focuses the force to a smaller surface area since the other teeth don't touch and help spread the load."
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62h08w | can y'all simplify what's happening with/about/around devin nunes? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/62h08w/eli5_can_yall_simplify_whats_happening/ | {
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"Charged with co-chairing the purportedly non-partisan House committee investigating the possibility that the Trump campaign acted in collusion with a foreign government to affect the outcome of the last election, Nunez instead acted as a partisan by going first to his party leaders instead of his committee co-chair with what he called new, classified and determinative information. \n\n(This is the very least of what he did; there is a possibility that he didn't just warn the target of an investigation but rather laundered information.)",
"He is Chairman of the House Intelligence Oversight Committee. In that position he would be resopnsible for looking into allegations of Russian interference with the 2016 election and any collusion in that interference by Americans, particularly Trump staff/surrogates. He as steadfastedly refused to look into this, and instead has tried to deflect attention away from it by claimin to have secret information supporting Trump's twitter allegation that \"Obama had Trump Tower wiretapped\" which, rather than share with the other members of h. s committee, he instead rushed to the white house to share with Trump staffers. And now it turns out that Trump staffers are the sources of that still unreleased and unshared information to begin with."
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2kvt8y | why don't space shuttles use nuclear energy? | Nuclear fuel would (I assume) be more efficient and cheaper. Why don't space shuttles, and other rockets use nuclear energy to fuel them? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2kvt8y/eli5_why_dont_space_shuttles_use_nuclear_energy/ | {
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"Chemical energy is like a bag of Doritos: it's not a perfect source of energy, but if you want to use it, you just open it, and start eating right now.\n\nNuclear energy is more like a fridge full of raw meat. It can provide you much more energy, but to actually use it, you need to have a whole kitchen full of appliances, and invest a lot of time. \n\nIn other words, nuclear reactors have fantastic energy-to-mass ratio: a small load of fuel would run you forever. However, they have very poor power-to-mass ratio: if you want a lot of energy not over the years, but over the seconds, you'll have to build a huge reactor. So huge it won't be able to lift itself with the engines you can realistically hook up to it.\n\nNow, that's now a problem for orbital vessels, since once in a stable orbit, you can take your to maneuver. So, a nuclear-powered orbital tower is a great idea, that would open deep space frontiers for humans. There are some engineering difficulties with that, and the public concern over nuclear energy doesn't help to get funding for these projects either, but people are working that.\n\nLaunch vehicles, however, require a lot of power right now. They have to fly with the acceleration about 1.5g, which is a hell lot if you want to maintain it for a long time (about 10-15 minutes). In fact, carrier rockets have the highest power-to-mass ratio among all non-explosive devices, outperforming even turbojets by more than 10 times. Currently there is no way to have a nuclear reactor of a comparable mass output comparable power.",
"there were plans for use nuclear explosion to propel space ships, but it's not easy and there is not too many other methods you can use. the closest to your idea is [Nuclear Thermal Rocket](_URL_0_), but it still needs other \"fuel\", not only radioactive elements. \n\nhere are other projects:\n\n_URL_1_",
"Not really a great answer, but space flights require a Push to help them break free from earths gravitational pull. AFAIK, currently we use nuclear power only to heat water, turn it into steam and use the steam to turn a turbine to generate electricity. While the fuel in the space shuttle ,actually called the propellant, produces enough energy burning itself that it propels the shuttle off earths pull. ",
"_URL_0_\n\n_URL_1_\n\nquite a few equations but you can ignore them and still get a good idea on what's going on",
"It's true that nuclear reactions tend to output greater energy over time than chemical ones, but chemical ones are far easier to engineer. When it comes to getting a payload into orbit, you need enough thrust to not only push your cargo into space, but also the engines and the fuel. This is the paradox of rocket science. More fuel and bigger engines mean you can go further, but also means you need more fuel and bigger engines to lift them in the first place.\n\nA nuclear reactor of any kind is a complex, heavy and cumbersome thing, certainly when compared to a (relatively) simple oxygen/hydrogen/kerosene ignition system. Ultimately, it's just easier to get the required lift and speed from burning some chemicals together than it is from heating hydrogen and expelling it at high speed as would be done in a nuclear rocket. The alternative, a nuclear pulse rocket, has huge drawbacks in terms of its waste products (see below).\n\nAlso, consider the safety aspects. When a chemical rocket explodes - as they have a tendancy to do now and then - you're left with a big fire, some debris and maybe some unpleasant and hazardous materials from burning plastics / metals. If a nuclear reactor expodes mid-air, you've then got radioactive material being dispersed over a wide area. (Consider that the Columbus disaster had wrekage spread over hundreds of square miles). There wouldn't be any nuclear detonations, the design of a nucelar reactor doesn't work on the same principle as a bomb, but you would have the same or comparable fallout effects.",
"There's actually been quite a bit of work on this! [Project Orion](_URL_3_) was one of the earliest ones. NASA is currently thinking [fusion](_URL_1_) power, but that's hard since we can't yet produce a net-energy-positive fusion reaction on Earth, let alone in a rocket. NASA is also looking at [thermonuclear](_URL_2_) propulsion for a future trip to Mars. Their [Design Reference Architecture](_URL_4_) has a LOT of info on the specs for any proposed reactors.\n\nThere were a bunch of prototypes made by the USSR and a couple by the US; some even [launched](_URL_0_) during the Cold War.\n\nOne of the biggest challenges is that you don't want the reactor to be what breaks you out of the atmosphere. It could potentially cause a lot of radiation exposure if anything went wrong. This is where SNAP-10A had its problems. That means you have to remotely start a brand new reactor in space, in addition to being able to reliably control it. To get the rocket out of the atmosphere, you'd need a detachable stage with traditional propulsion engines.\n\nThe biggest advantage of using nuclear propulsion is that it is much lighter than current propulsion systems, which means you can accelerate more and go faster. At that point, efficiency doesn't matter as much.\n\nI'm not sure on cost of building a nuclear-powered rocket. The up-front cost of researching and testing would be much greater than continuing to use traditional means, which is the biggest barrier to implementing thermonuclear rockets.\n\nSource: Did a year of undergrad research on the topic. Let me know if there are any more questions, I'd be happy to clear anything up.",
"Like with the Antares rocket the other day. If you determine that it's off course and the decision to self destruct is made, you just crop sprayed nuclear fuel over your own country.",
"For launches, the most valuable of a rocket engine is the thrust-to-weight ratio, or how much more it can lift than it itself weighs. Nuclear rockets, while very efficient, are also very heavy - they can only lift about 5 times more than their own weight. For comparison, for a modern chemical rocket engine this number is on the order of 100-150. That means that despite their inefficiency, chemical rockets are much better at getting things into orbit.\n\nFor maneuvering in outer space, that matters less and a nuclear rocket would indeed be a great solution for going to the Moon, or Mars. But we don't do that on any significant scale, so we don't use nuclear engines.",
"I think we miss interpret what a nuclear fuel do exactly. Nuclear reactor heats up water to create steam which spins a turbine to generator electricity. The issue here is the \"waste\" is steam which is converted back to water through the cooling system nuclear reactor have. So if we were to imagine that same reactor in a space shuttle, the system would require an endless amount of water or a way to cool down the water for the reactor again. \n\n\nSo how about we modify the nuclear reactor to heat something else to generate electricity. I assume genus minds can modify it to work. But the another main issue is a nuclear reactor is a \"control\" radiation death machine. A normal nuclear reactor would have a few feet of concrete to stop the random radiation that is given off. Plus metal tend to stay radioactive once radiated. So a tiny shuttle, made of metal, having thick heavy concrete walls is not efficient. ",
"because nuclear energy is some kind of anachronistic union of atomic fission and a 1800s steam turbine. \nthrow in some decorative brass plaiting and its something you'd expect to see powering a steampunk airship\n\nbatteries last forever but it doesn't have the power output to throw something into space. you need the explosive power of something that lets go of all its energy at once."
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3a7dx8 | what's up with all of those lines on the back windshield? | I'm sitting in a parking lot, and wondering, what's with all of those lines? Do they measure anything? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3a7dx8/eli5_whats_up_with_all_of_those_lines_on_the_back/ | {
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"No, they are made of material that conducts heat better than glass. This is done so that, when you have your rear defroster on, heat gets channeled through your back windshield faster and thus melts ice/evaporates fog more quickly.",
"They're rubber with wires in them that heat up when current is applied. They're used to melt snow and ice off the window.",
"The lines on the back windshield are heaters, designed to defrost the back windshield if necessary. You have a button on the dashboard that will activate it.",
"They're for the rear window defroster.\n\nTurning it on sends an electric current through those lines. The lines are resistant to electrical flow so much of the electricity is converted to heat (basically an electric heater or toaster). This heat either evaporates the vapor or defrosts the ice on the rear windshield."
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d3wqho | how do delivery companies like ups and fedex deliver my packages so quickly when my item is on the other side of the country? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/d3wqho/eli5_how_do_delivery_companies_like_ups_and_fedex/ | {
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"If desired, air cargo. It isn't hard to get packages across the country when you load then up in a plane and fly them most of the distance.\n\nThis is also why guaranteed 2-day/next-day/overnight services are typically very expensive, especially for large/heavy items.",
"The key is ride sharing. Consider that every package has a source city and every one has a destination. If you put a single sorting warehouse somewhere central, then you can ride share in AND out.\n\nFor example, one package comes from Los Angeles, the other from New York, and they’re both headed for San Francisco. Yes it would be cheaper to drive or fly LA to SF directly, but the cost of NY to SF is many times larger.\n\nWhat if you put a hub in Kansas? Both packages go there first, and get put on the same flight out to SF. Now each person pays about the same to ship and they can still both ship in about the same amount of time.\n\nNow multiple that across several million packages across thousands of cities...several large geographically central hubs...and that’s UPS and FedEx.\n\nAs a bonus, suppliers can strategically place their warehouse IN that same city as a UPS or FedEx hub and save one of those flights, getting their goods to you even quicker.",
"It’s fairly easy to get between any two points in the world with a decent number of people in them in the span of a single day. Given that, if I wanted to take a package to someone almost anywhere in the world, I could probably hand deliver it to them within 24 hours if I knew where I was going and had the money to travel.\n\nSo the travel portion isn’t really the hard part. It’s the logistics of doing that with a lot of different packages going to a lot of different places all at once. That requires a lot of tracking and organizational work with hubs that allow packages from relatively the same place that are going to relatively the same place to be grouped together, shipped at once and then dispersed to the correct places on arrival."
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2nzufi | how and why certain species of birds imitate noises? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2nzufi/eli5_how_and_why_certain_species_of_birds_imitate/ | {
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"Exactly like 'we' learn to speak. If you practice enough (and if the sound is physically capable of being produced from your physiology) you can produce many bird / other human sounds as well.\nSome birds have that section of neuron particularly well developed.\nI don't know as to why they do it. ",
"Birds often have complex courtship rituals. Bird song can be one of those. For many birds there is very little variation, and you will hear pretty much the same call over and over again. But for species that mimic other sounds they are showing off how smart they are that they can memorize and exactly copy such a large and varied set of sounds. They collect these sounds over their lives, and older more experienced birds will often have better collection. This is similar to the way some birds dance rituals are extremely involved and show a large degree of personalization."
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alnjg3 | in a big city like chicago how are the drainage and sewer systems maintained during winters, when temperatures drop to like -20 and everything just freezes instantly? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/alnjg3/eli5_in_a_big_city_like_chicago_how_are_the/ | {
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"There's this thing known as a \"frost line\". It's the depth that the ground will freeze to, given a prolonged temperature.\n\nCities know how cold it can get, and bury their sewage lines well below the frost line. This ensures that they don't freeze, even in extremely cold winters.",
"While the frost line is important for pressurized water main, most sewers are actually hot in winter. Most of the sewage comes from your house, where the water is well above the freezing temperatures when it get to the underground pipes. The combined heat from every waste in every house the pipe is connected to will keep everything warm, combined with the fact the pipes themselves are buried underground, with the ground itself acting as insulation. That’s why in very cold temperatures you can see steam coming out of manhole covers. \n\nDrainage can freeze has it’s doesn’t typically contains any household wastes. Here the frost line is a bit more important, but not critical since there’s no pressure. It’s not as critical as water pipes, which can burst if they freeze because of the pressure. \n\nSource : Civil engineer in Montreal. \n\nEDIT: As someone else pointed out, the fact the water is constantly moving in sewers helps a lot. Pressure pipe, like the water line from the street to your house, can freeze in extreme cold if you’re not using it. That’s why it is recommended to leave a tap running if you’re worried about your water service to freeze. ",
"First of all everything does not freeze instantly. Larger moving bodies of water takes a good while to freeze. And secondly it is under ground below the frost line. This is normal in all cold countries. In super cold places permafrost can cause other solutions. ",
"Native Chicagoan chiming in: everything everyone has said about the frost line is true, but Chicago doesn’t regularly drop this low. While we’ve seen windchills around -25 semi-frequently the last few years, that doesn’t affect subterranean infrastructure as much. \n\nThe current temperatures are very much an anomaly. Usually the “true temp” taps out in the single digits Fahrenheit. We haven’t seen a freeze like this since the 80s and it is affecting infrastructure that normally doesn’t have a problem. ",
"Dig down a bit and the temperature is always around 55 degrees or so. Constant, year round, regardless of surface temperature.\n\nThe Earth is a great insulator. The interior of the Earth is also very hot. Dig down too deep and things will get too hot. Dig down a little bit, just enough to go beneath the surface so that the ground itself insulates against the outside air temperature, and things start to warm up again.\n\nThis is why wine cellars are a thing. Wine likes a constant temperature. Put your wine underground, in a cellar, to keep it at a constant temperature regardless if its -20 degrees or 110 degrees above ground. Before an era of refrigeration or electricity this constant temperature was critically important to storage. Even today its common for wineries to have large underground caves for storage. The caves may be natural or man made but regardless of origin they serve to keep the wine at a constant temperature.\n\nDirt above the cave prevents heat from reaching the interior. The cool, wet soil is constant, and the warmth of the planet itself prevents things from getting too cold.\n\nVery deep mines get hot. Some of the deepest mines on the planet are so hot due to the heat of the Earth miners can only work short shifts in refrigerated protective clothes before overheating. Wine cellars and sewer lines dig deep enough to be protected from weather above, deep enough to get a bit of warmth, but not too deep."
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a4ojdt | why does rubbing alcohol get rid of sticky stuff so well? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/a4ojdt/eli5_why_does_rubbing_alcohol_get_rid_of_sticky/ | {
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"The chemical structure of alcohol lets it grab on to pretty much any substance, to the point of 'equaling out' the solution. Alcohol will bind to parts of a substance enough that the substance can't hold itself together, by wedging itself between the molecular structures.\n\nwhen that happens to a substance, it melts. Just falls apart.",
"I am not a chemist, but here is how I understand it. Some things dissolve well in water - sugar, for example. Some things do not dissolve well in water - certain types of glues. Alcohol has a dissolving ability for those glues, thus making it very easy to remove them after applying alcohol. Is a chemist in here who could tell us more about the process?"
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zwnvs | when i hold a microphone to a speaker, how is feedback produced? what is the science behind it? | I can understand the concept of.... y'know... feeding nothing into nothing destroying the universe, but what actually causes the EEEEEEEEEEEEEEE sound? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/zwnvs/when_i_hold_a_microphone_to_a_speaker_how_is/ | {
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"Each time a microphone picks up a sound, and replays it through speakers, there's just a little bit of distortion added. You can hear it just faintly when there are noises.\n\nHowever, when there's silence, the microphone picks that up, adds a little distortion, plays that, hears the sound now with a little distortion, adds a little more distortion, hears the sound with that distortion added, adds even more distortion, etc. Pretty soon it gets amplified from just a little crackle added to your voice (or the silence) to a raging scream because of the feedback loop."
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45h4ye | how do dogs know their food is their food? i mean their dog food in their bowls? it looks and smells nothing like real food | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/45h4ye/eli5_how_do_dogs_know_their_food_is_their_food_i/ | {
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"How do people know their food is their food? I mean their people food in their bowls? It looks and smells nothing like dog food",
"Dogs eat or at least chew on a disturbingly large number of things that are not real food, or in fact, intended to be food of any kind. After the first bite, it is apparently sufficiently food like for them to continue.",
"Well, what is real food? Obviously a dog isn't smart enough to rationalize concepts like spices. Their sense of smell and criteria for food is very basic. If it smells like meat or anything they've ever been fed or ate and came to realize it was food, they will eat it.\n\nThat's also why dogs eat poop and garbage. To them, it smells like food. (And that is also why dogs do not like to take their medications. Because medications do not smell like food, so it is not to be eaten) "
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9hca1b | why is it that when you put pressure on your eyeball’s corners, you can see something that looks similar to the iris of an eye opposite the side you’re pressing on? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9hca1b/eli5_why_is_it_that_when_you_put_pressure_on_your/ | {
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"When you put pressure on your eyeball's corners, you are deforming the lens which focuses light. This can create shadows in your vision.\n\nIf you've ever looked at the shadow of a clear bottle of water, you've probably noticed this effect. The water acts as a lens to focus light on the shadow; if you squeeze the bottle, dark spots will form in the shadow.",
"Your eye acts as an inverted camera. The inside of your eye acts as the sensor or film for the light that enters it.\n\nIf you drew a line from an object to the top of your eye through your pupil, it would hit the bottom of the inside of your eye. Likewise, a line from an object on the right goes through your pupil to hit the inside left of your eye.\n\nWhen you press on the corners of your eye, a few things may happen. The denting in the eye makes one part of the sensor/film bend so that it does not receive proper light, much like a bump in something flat can cast a shadow. This makes the area of your vision appear dark. The pressure may also cause the light sensitive cells to misfire, and assume that it's seeing something. Lastly, pressing too much will prevent blood flow to the area so the cells cannot properly send the signals to indicate light to your brain.\n\nThis appears on the opposite side of where you are pressing due to the inverted camera nature of our eyes."
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141pdk | if internet was created to allow independent connections from each computer, how is it possible to just shut down a full state connection (aka syria)? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/141pdk/if_internet_was_created_to_allow_independent/ | {
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"***Edit: Here's a [crude drawing](_URL_0_) to help visualize it.*\n\nBob and Joe are friends. Joe lives just around the corner from Bob, so Bob decides to walk to Joe's house. He walks down his street, turns right at the corner, and walks down Joe's street. He then walks down the path from the sidewalk to to Joe's front door.\n\nSuzy and Jill are friends. Suzy lives around the corner from Bob in the opposite direction of Joe (left at the corner instead of right). Jill lives next door to Joe. Suzy decides to walk to Jill's house, so she walks down her street, passes Bob's street, and continues onto Jill's street until she turns to walk from the sidewalk down the path to Jill's front door.\n\nEven though Bob and Suzy can each get to their friends' houses, their friends share a street, so they both have to walk down the same section of road to get to their friends' houses. There isn't a single road that goes straight from Bob to Joe, and there isn't a single road that goes straight from Suzy to Jill. They have to share *part* of the path.\n\nOne day there is road construction, and Joe/Jill's section of the street is blocked off at the corner (shown in orange in the picture). Now neither Bob nor Suzy can reach their friend. Bob and Suzy could theoretically walk to each other's houses, because the intersection itself isn't totally blocked. Only the section that goes to Jill and Joe.\n\nNow imagine that the road is a wire that you send a message through. In order to actually make a connection directly to someone else's computer, there would have to be a single wire going directly from your computer to their computer. Really there are hubs where a bunch of wires connect, like the intersection of Bob and Suzy's streets. That hub is then connected to other hubs where the wires split off again to go to the individual houses, like how Bob went down the path to Joe's door, and Suzy went down the path to Jill's door.\n\nTo shut down the connection to a large area like Syria, one would shut down the hubs that allow connections within that area.",
"You can think of Internet access like a person entering or exiting a country. You're free to get on a plane and leave the country and comeback. Everyone can do this using a passport (IP). But now imagine the government shuts down all airports. Now no one can leave or enter, cutting connections with the outside world. ",
"Well, Briefly. The internet is not exactly everything it was originally intended to be.\n\n[Check out this image](_URL_0_)\n\nYou are right that originally we thought it would look more like the 3rd image, but mostly it looks more like the second, and some parts even like the first (the internet is really really big)\n\nSome of those center points of the stars are called ISPs. If you take out the ISPs, then nobody is connected to one another anymore!",
"The internet uses hubs. Computers don't all connect directly to one another, they connect to a series of hubs to get information in and out. If you shut down one hub, you can black-out an area. \n\nThink of it like a giant highway system connection cities. There is often more than one way to get from one city to the next, but just as often you need to pass through a particular interchange/roundabout/rotary to get to the off ramp to a particular city. If you block all the traffic to that off-ramp/highway exit, you can block off an area. Some cities have more than one off ramp, so you may have to close down two or three highway exits, but it can be done.\n",
"[How Syria Turned Off the Internet](_URL_0_)",
"E.G. not aka",
"There are typically 2 ways to take the Internet offline for an entire nation.\n\n1. If the government owns the Internet providers or\n\n2. If the government owns the power suppliers of the nation\n\nIn the case of Syria both of those things happened. The government can simply shut off power to the Internet provider, or stop supplying service if the provider is controlled by the government",
"While the top answer is a good explanation of how things can end up separated on the internet, it is not actually what happened in Syria.\n\n_URL_0_ is a good technical write up of what actually happened.\n\nI'll try and make this ELI5 ready. In terms of the internet, there is a model called the OSI model used to descibe the different layers of things riding on a connection on the internet. It is described in terms of 7 layers, and in order for the upper layers to work, all layers below them must be working. As an example, in order for Layer 5 to work, layers 1-4 must be functioning properly. In order to build a 7th floor to a building, the first 6 floors must be able to support it.\n\nThe first layer of the OSI model is the Physical layer. In order for anything to connect to the internet, there needs to be a physical connection between it and something else connected to the internet.\n\nthe 2nd layer doesn't matter in this example with Syria, so we'll just skip over it.\n\nAnd the 3rd layer is called Network, which describes where people get IP address, and the easiest way to get from one IP address to another. Essentially, layer 3 is where you would get your home address, and the layer responsible for mapping how you get from one person's home address to another person's home address.\n\nIn the example with roads, the road being under construction would be an interuption at layer 1. In reality, what the Syrian teleco most likely did was an interruption at layer 3. This would be like saying that all the sudden, the entire neighborhood that Bob lives in had all their street signs taken down. No one knows how to get from their address to Bob's address because the sign \"Syria St.\" is missing, and they don't know where to turn. Its not that the roads are under construction. Its just that no one knows where Bob's neighborhood is now. ",
"just think that if in your house you unplugged the router providing wifi and wired access to everyone around it. same deal. they just turned off a very big router....to the whole country.",
"A lot of these answers assume that the physical connections into Syria have been severed. Last I knew, this was *not* the case, but rather the BGP routes for Syria's IP blocks were withdrawn from Syria's edge routers.\n\nTo translate that to an ELI5:\n\nImagine that you're in a room with a bunch of doors and you have to put mail through slots on those doors. You only know who is behind which door because the people on the other side shout \"HEY, I'M BEHIND DOOR #1.\" Occasionally people shift rooms or new people show up behind a door. When they shout \"HEY, I'M HERE!\" that's a BGP announcement and you're a router. When someone leaves one door to go to another they say \"HEY, I'M NOT HERE ANY MORE!\" so that you stop sending their messages through that old door.\n\nNow imaging that you **have** to respect those messages, because it's the foundation of the Internet and it's just how it works. What Syria just did was have every one of their country's edge routers say \"We're not here any more!\" within three minutes of each other. In turn, all of the other routers said \"Hey guys, they're not here any more\".\n\nNow, since the Internet is normally decentralized, if one or two routers shout that they're not there anymore, other routers will just get extra messages to pick up the slack, but since Syria controls all routers, they were able to make them *all* say that they aren't there any more, all at once, isolating Syria from the rest of the world.\n\n[Cloudflare](_URL_0_) has a nice blog post about this.",
"A small town is full of light bulbs. But there may only be one road into that town. Take out that road, and nobody sees the light.",
"A \"like your 5\" answer would be this:\n\nImagine every computer is like a leaf on a tree, and the branches and twigs are the internet going to the leaves. If I cut the branch going to your neighborhood's computers, then you and your neighbors will no longer have internet.\n\nIn the real world these branches and trees are referred to as \"hubs\" or \"nodes\". They are the place where internet connections get routed and branched off into neighborhoods. Some countries have their entire internet funnelled through one or two majors nodes (e.g. China) so that they can control all traffic easily. I don't know if Syria does this, but apparently they knew how to take out the major nodes.\n\n"
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vj319 | what is the muslim brotherhood? (as unbiased as possible) | what is it? what is their goal? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/vj319/eli5_what_is_the_muslim_brotherhood_as_unbiased/ | {
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"It is an international Islamist social and political movement which seeks to promote and install Islam as the basis of social life from the family to the state. They're similar in some respects to organizations like the Salvation Army, doing charity work, operating hospitals, and promoting religious faith as a means to solving social problems. Unlike the SA and other similar groups, the Muslim Brotherhood maintains a strong political motive and actively seeks political power in the countries in which it operates, sometimes through violence.\n\nThe Egyptian wing of the movement which has been in the news lately has openly rejected violence and is seeking to come to power through democratic means. While they are tolerant to a degree (expressing a \"respect\" for the \"personal conviction\" of others), there is much valid concern on the part of secular and Coptic (Christian) Egyptians that the type of government the MB offers (essentially a soft Muslim theocracy built on democratic underpinnings) could lead to discrimination and oppression.",
"Has there been any previous instance of the muslim brotherhood being in power in a democratic country?"
]
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[],
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7b2gia | why, in the days of dial-up internet, if someone picked up a phone on the same line it would drop the connection. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7b2gia/eli5_why_in_the_days_of_dialup_internet_if/ | {
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"Data was being communicated via sound on the phone line. If someone picks up an extension, that adds noise via the microphone on that phone, and causes errors in data transmission. If there are too many errors, the connection is lost.",
"Dial up modems communicate by noises over the telephone, the beeps and buzzing noises. For two modems to stay in communication, they have to establish and maintain a connection. If it doesn’t, the models lose track of what they’re saying to each other, so to speak. Sort of the same way that if you and I were talking and other people were talking loudly around us, at some point we wouldn’t be able to hear each other over the other voices. We’re still making noises at each other but we’ve lost track of what we were saying and aren’t effectively communicating anymore. \n\nLifting up the phone, even the ambient background noise and the click of the receiver being picked up is enough to break the connection, since the modems are relying on such subtle noises to talk. ",
"Imagine you're playing a huge game of battleship on the phone. You're taking turns telling each other moves, like C8, and giving responses.\n\nIf you lose your concentration, and miss something, the whole game is ruined -- did you try C8 already? Did your opponent sink your battleship?\n\nNow imagine your little sibling picks up the extension and starts yelling \"d 10! X eleventy one! Sixty q!\" You have to backtrack, maybe start the whole game over again.\n\nYour computer has the same problem when you interrupt it. The sequence of numbers it's using to talk loses meaning when a chunk goes missing.",
"In the really early days, when the modems were [physical cradles] (_URL_0_) into which you set the handpiece of the phone, you could listen in on another phone without it dropping the connection.\n\nOnce they started wiring the phone lines into the modem, without going through a set of speakers and then microphones, they could make them much faster because the speakers and microphones degrade the signal. Once they got fast enough, just having a speaker looped into the circuit in parallel, like lifting the handset on another line, would degrade the signal enough to cause problems."
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2aac71 | space-time relation | I'm trying to wrap my head about the concept of space-time and how it works~ | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2aac71/eli5_spacetime_relation/ | {
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"This is a very nonspecific question, but I'll give it a whack. If this doesn't address what you're curious about, feel free to ask more.\n\nBecause of the way that events occur, it's necessary to not only have physical coordinates for events, but also temporal ones as well.\n\nThere's a marked separation, for example, between two events that occur in exactly the same space but are separated by time. If you have a bulb in a fixed position and flash it twice, both the flashes come from the same location but are not the same.\n\nThis is why time is generally married in with space to make spacetime.\n\nAlso, both space and time share other things in common - they're both, for example, twisted by similar amounts when viewed as inertial reference frames (this means a reference frame which is not undergoing acceleration) with different velocities.\n\nAs you get faster and faster, you get length contraction along the axis of movement, as well as time contraction. Essentially things that are moving very rapidly compared to you appear to become squashed along the direction they're travelling, and appear as if time for them slows down.\n\nLikewise if you're moving very fast compared to something else, that other thing appears to be stretched out along the direction of relative movement, and appears as if time for it is moving faster."
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25sqqd | does a drug that prevents the spread of hiv mean we could eradicate the disease? if so, how do we coordinate that kind of effort? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/25sqqd/eli5_does_a_drug_that_prevents_the_spread_of_hiv/ | {
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"Supposing it was 100 percent effective, and we could get absolutely everyone to take it, and it could prevent transmission mother-to-child, then we could eradicate it in a generation. But the first two assumptions, at least, are false: the pill has 99 percent efficacy (still pretty great), and there's no way we could finance it for everyone, distribute it to everyone, and get everyone to take it, (because it seems like you need to keep taking it for it to keep working), so it would take a great deal of time. This would be like eradicating polio; find the places it's most prevalent, dose as many people as possible, and spend a few generations stamping it out. Then, stay vigilant for outbreaks."
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32kapw | why do our bums feel numb after sitting down for a long time, even on a soft surface? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/32kapw/eli5_why_do_our_bums_feel_numb_after_sitting_down/ | {
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"When we sit on our butts, we compress and flex our butt muscles. Essentially when we compress and flex them over time, they tend to get a little tired. This would be a simple answer to your question."
]
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[]
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330vv8 | pi is irrational, therefore it goes on forever. could that mean that, within pi, you could find other irrational numbers, like √2, and vice versa? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/330vv8/eli5_pi_is_irrational_therefore_it_goes_on/ | {
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"We don't know. \nObviously if you remove some of the first numbers of pi you get a new irrational number from pi. \nBut we know that pi can't contain something like √2. \nBut it could in theory contain something like e.\n\n\n/r/askscience has several more detailed posts about this(I guess they go a bit beyond eli5) \n_URL_0_ \n_URL_1_ \n",
"Can pi contain another pi? ",
"Well, 1.010010001.... May go forever and contain infinite numbers but you won't find any number 2s in it. Sooo.... If you have number that never ends and never repeats, you also got a number (like 2*original number) that won't be in the original number. Also, if pi contains 2^.5 then you really can't have 2^.5 and find pi in it. \n\nNow, more beer. I should be studying and must make sure I can't do it.",
"Of course you can. Start with the binary representation of pi. No matter where you are in the expansion, there will always be both a 0 and a 1 after that point (otherwise pi would be rational). To make the binary representation of any other fraction, rational or irrational, just select the next 1 or 0 that you need to match the expansion of whatever you are looking for."
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fk9p00 | how is it possible to cure people from hiv? and if it's possible why are there only two cured people? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fk9p00/eli5_how_is_it_possible_to_cure_people_from_hiv/ | {
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"At the moment under *normal circumstances*, it's usually not possible to cure HIV with modern medicine. HIV is becoming more treatable than it used to, by a long shot. Anti-retroviral treatments have improved significantly over the last few decades to the point where they can sometimes reduce HIV to undetectable levels, meaning that HIV+ people can live long and healthy lives and have a significantly reduced (even negligible) chances of transmitting the disease to a partner under the right circumstances.\n\nThe two people who have been cured, to date, received a special treatment for lymphoma while also being HIV+. They had stem cells from bone marrow transplanted into them from donors, and (I believe) had donors who were specially picked for having genetic resistances to HIV as well. After the treatment (which involved chemotherapy and radiation for at least one of the cases as well), they were functionally cured of HIV and able to stop taking retroviral drugs.\n\nThe issue with this treatment right now is that it's fairly high-risk and wouldn't be a good idea outside of treating cancer - for most HIV+ people, retrovirals are just the safer option. But the fact that it's occurred twice under similar circumstances does open the door for future research into ways to make this treatment safer and easier, potentially setting researchers on the right path towards a true cure down the road.",
"The two people who have been cured so far are special cases. They are people who have HIV and lymphoma, which is a type of cancer. The patients received stem cell transplants for their cancer. \n\nThe stem cell donors have genes that caused them to be resistant to HIV infection. When the cancer patients received these stem cells, they suddenly gained a resistance to the HIV infection. Their immune systems cleared out the HIV and they now appear to be cured.\n\nSource: _URL_0_\n\n\n\nWhy only two people so far? That's not as clear, because we have so few examples to look at it. Three likely reasons come to mind:\n\n(1) The process of getting a stem cell transplant is risky and difficult. The extra risks may not be justified for people with HIV who are otherwise healthy.\n\n(2) Not that many people have natural HIV resistance, so there are also very few donors whose stem cells can cause this.\n\n(3) Even IF there were a lot of donors who could help, this outcome has only happened twice in 12 years. It's not guaranteed that this could happen consistently enough for it to become a regular treatment. We need to know more."
]
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11023t | how does the president, who i'm assuming has a 40+ hour, 7 day a week job, campaign? | When I read about how often presidents are campaigning, and practicing debates, isn't that time directly being taken away from meeting with foreign statesmen, advisers, cabinet members, departments, keeping up with current events, and reflecting on critical decisions? How much time do they put into campaigning? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/11023t/eli5_how_does_the_president_who_im_assuming_has_a/ | {
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"They work on the plane/bus between campaign stops.",
" > who I'm assuming has a 40+ hour, 7 day a week job\n\nThis assumption is wrong.",
"This might surprise you but the president is just one person representing a large group that has an even larger group of assistents.",
"Because they never get just a 40 hour day. A White House \"workday\" starts at around 6am and ends at roughly 8pm, at least for a lot of the general staff."
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29ahpm | why people keep saying that banks/bankers are bad? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/29ahpm/eli5_why_people_keep_saying_that_banksbankers_are/ | {
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"A lot of the hate is justified. Lenders did take extraordinary risks that hurt the economy and they did lend to people they knew couldn't afford the loans. But a lot of people are anti-bank because they think banks by their nature are bad, and those people are morons and have no grasp on how modern economies work.",
"If you're referring to the banks that helped cause the financial crisis in 2008:\n\n* Many took the money people put in the bank and used it on investments they didn't understand and still didn't understand because some ratings agency said they're okay, winding up losing a whole lot of the money people put in the bank.\n* Many gave out loans to people without actually actually checking if they were telling the truth. In other words, they loaned your money to someone without checking to see if they could pay it back.\n* In the midst of the recession, the government loaned them money at near 0% interest rate with the expectation that they would then take that money and loan it to small businesses to help the economy recover. They didn't do that and used the money they borrowed to pretend that everything is okay.\n* Despite all this, they pretend that they know exactly what they're doing and complain that the real reason is there are too many rules telling them how to behave properly.\n\nThat's why I don't like them. Other people may have other reasons."
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84kldo | how does expelling russian diplomats from the uk punish russia? what do the diplomats do? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/84kldo/eli5_how_does_expelling_russian_diplomats_from/ | {
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"Expelling diplomats over a conflict is like sending your partner to sleep on the couch. It doesn't solve the argument but makes it clear that the conflict is to be taken seriously since communication is cut off. ",
"Expelling diplomats is a country's way of saying \"we don't like you\" or \"we disapprove of something you did\" without really doing anything. It's largely symbolic and usually part of a tit-for-tat diplomatic dispute. As for what the diplomats do, I don't know that it's been released what their jobs were in the UK. It's not common for host countries, when expelling diplomats, to send home foreign intelligence operatives working under diplomatic cover, so it's possible, but purely speculative that some or all of the diplomats being expelled are with Russian Intelligence. ",
"I heard an analysis of this on BBC Radio 4 yesterday. Embassies are quite blatantly used for espionage, but they also have normal functions to perform. The specific Russian diplomats expelled are allegedly high ranking officials, meaning their jobs are more difficult to replace. Therefore the idea is that the rest of the staff have to struggle to get the embassy running normally, forcing espionage to be prioritised less."
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11mpuh | what are the details of romney's five-point plan? | Governor Romney keeps talking about his five point plan, and I honestly couldn't tell you the specifics of any of it, despite watching the debates, reading political magazines, and following blog coverage of the election. What are the specifics? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/11mpuh/eli5_what_are_the_details_of_romneys_fivepoint/ | {
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"there are no specifics, and he's actually defended the fact that there are no specifics\n",
"No specifics. When you change your stance on topics so much, the lack of specifics are the best policy to look credible."
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2900to | ontology in computer science | I have a background in philosophy, but I would like an example or two as to what ontology means perhaps from a consumer's perspective. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2900to/eli5_ontology_in_computer_science/ | {
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"Can you clarify this? First you ask about computer science in the title, and then you ask about a consumer's perspective.",
"In CS, ontologies are collections of related concepts. For instance, the lab I work in does a lot of work with medical systems so we deal a lot with medical ontologies. In an ontology designed for medicine you would be able to search for a term like \"heart attack\", and the ontology would know that there are other terms for it such as myocardial infarction, it would know that it affects the heart, and it would know anything else that the designer of the ontology would think is important. For another example, you might have a disease ontology, where you can search for a disease and the ontology would know related diseases, disease classifications, symptoms of the disease, treatments, etc.\n\nIn CS an ontology is really just a list of things plus any relevant connection between those things where relevance is determined by the person making it."
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aikdm6 | how has the cost of living/schooling and economy in general inflated to such a degree? is there a way that we can fix it or will it simply become worse? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/aikdm6/eli5_how_has_the_cost_of_livingschooling_and/ | {
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"Instead of charging a reasonable amount for services, employees, etc., universities compare costs with other universities. Thus what should a math teacher be paid? Well what do math teachers at other universities get paid? Using an untethered closed loop can only make prices go higher, because everyone gives their permission for prices to rise.",
"No one has mentioned this yet, but in part because of drastically increasing amenities and administrative fees for colleges. \n\nThe number of jobs mandated at colleges is MASSIVE. You need the ethics committee to go over all the proposed projects, you need the diversity committee, you need the rape counselors, you need specially trained police, student escorts, parking commission, specially trained judges, department of conservation, finance idiots to lose the endowment money, marketing wiz to get the students to even know your college exists, training for all the teachers in whatever's important that month, auditors to make sure the professors don't waste money (or steal it), charity people to harass the graduates to give them more endowment money. And on top of all that you need lots of people to manage the people you have to hire.\n\nAmenities are just nice things for the students - you can no longer expect them to go to the grocery store and live cheap. To attract good students you need emergency call boxes, non-shitty chef prepared food for all cultural groups, a gym, a nice stadium for sports, a giant TV for the stadium, luxery boxes for the stadium, a pool (heated of course), comfey chairs, a nice student union, clean grounds and buildings, TVs in the dorm rooms, a computer center, good cellular signals for all major carriers, free campus wi-fi with no dead zones, ultra-fast internet so students can stream Netflix.\n\nAll of this stuff is \\*MASSIVLY\\* expensive and that's reflected in the tuition. You ask how someone can get a 200k student loan bill and the answer is they spent 5 years at a luxury hotel and counseling center."
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1hgouw | electric fields | I don't really understand how an electric field works. I get electric force, it's when charges interact and depending on their charge they'll either attract or repel. That's for two charges. So with electric field, we look at one charge and introduce a test charge and it's influenced by an electric field? What electric field? What causes it, the force? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1hgouw/eli5_electric_fields/ | {
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"Think about an electric field in terms of a gravitational field. You're in a gravitational field right now - drop something, and it falls. If that were an electric field, things would be much the same, except if you dropped a positively charged thing, it would fall, but if you dropped a negatively charged thing, it would fly upwards. Unlike a gravitational field, an electrical field is easily controlled by turning it on and off, changing its direction, etc. ",
"Imagine there's a charged object just sitting there doing nothing. If we introduce a test charge, the test charge will be either attracted or repelled by the object. Depending on the distance from the object, the test charge will experience a different strength of attraction or repulsion.\n\nThis is where the idea of the electric field comes from. It's a mathematical description of what the attraction/repulsion force would be on a test charge due to the charged object. Since the force depends on the position of the test charge, we use a *field* to describe it, because we need to be able to calculate what the strength is at a given position. More specifically, we use a *vector field*, because we need to know both how strong the force is, and which direction it's pointing in.\n\nWe don't really think that the field is a real thing, in the sense that there's some actual field permeating all of the universe. It's more of a mathematical construct that we can use to explain the physics than anything else.\n\nAs for what *causes* the attraction? In quantum electrodynamics, the force is mediated by \"virtual photons.\" Mathematically, at least, the charges trade photons between each other, which is how they manage to exchange energy between each other, and thus attract/repel. Again, though, it's not really clear whether they're *physically* real, or if it's just a way to make the math work out really nicely. I've heard some really elegant explanations to make sense of how they may or may not be real, but I'm not really equipped to delve into those."
]
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[],
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cq5zai | if we heat up food to kill germs, why can't we do it all the time? | If the idea of heating food above a certain temperature is to kill the bacteria to make it safe for eating, why is it that if you leave cooked meat in the fridge for a week or so, or leave cooked meat at room temperature overnight, that suddenly, no matter how much you reheat it, that food is waste and is no longer safe for eating even if heated up to 150 Celsius or above? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cq5zai/eli5_if_we_heat_up_food_to_kill_germs_why_cant_we/ | {
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"Heating food will kill the microbes, not what the microbes left behind. Without excessively cooking the spoiled food you're not able to remove the toxins left behind by the microbes and you'll get sick. Destroying those toxins with heat would effectively mean, \"cook until ash\".",
"Another point: cooking isn't just for killing germs.\n\nWhen you eat meat, for example, the nutrients you are trying to get to are inside the animal's cells, protected by the cell membrane. Cooking destroys this membrane and allows the nutrients to be absorbed better (it's why when you cook a steak, the juices of the meat start to come out)",
"A third point: bacteria can shrivel up into heat resistant spores, called endospores. This means that when you let enough bacteria build up, even cooking it won't get rid of enough of them. Also, heating can act as a trigger to start the endospores waking up, which means the food will be even more likely to make you sick than if you just ate it cold."
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[],
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blzzwh | howcome the liver shot is so effective in boxing? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/blzzwh/elif_howcome_the_liver_shot_is_so_effective_in/ | {
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"I mean, hitting an organ not really protected by the rib cage is pretty painful, but since the liver is an important organ, the body probably focuses more on it when any damage is done to it.",
"The liver is on the right side of the body and is partially unprotected by the rib cage. A hard and fast blow right below the ribs can rupture the liver causing your body to go into shock and panic. You immediately hit the floor as your body needs all the blood it can in your liver. Due to the fact that the liver is a vital organ and without it you will die, so your body will try to save it. For a more in-depth and educational video watch this: _URL_0_"
]
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[],
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"https://youtu.be/KVZbEE0nx70"
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bz02xh | how animals can carry diseases but not actually have those diseases | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bz02xh/eli5_how_animals_can_carry_diseases_but_not/ | {
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"You do this too. You carry around all manner of intestinal bacteria that are kept segregated from the rest of your body. If they get into other animals or into places they don't belong, they can cause a serious infection. They'd rather just ride along with you indefinitely.\n\nYou also occasionally carry around human-specific cold viruses that are just a minor annoyance to you but always have the risk of jumping species by accident.\n\nLethal bacteria and viruses like bubonic plague and ebola and smallpox aren't purposely trying to kill you, this isn't a viable reproductive strategy. The want you up and about and passably healthy to spread the passengers far and wide forever.\n\nWhen they accidentally get into a species they haven't evolved to coexist with, the infection is too aggressive and the animal and the infection both die.",
"A good example is the Bubonic plague.\n\nMost people attribute rats to spreading the disease when it was actually fleas. Rats would carry the fleas, fleas would bite and spread the plague. \n\nThere are also diseases that have no symptoms for animals, but cause severe reactions in humans. \n\nThere are also examples in humans as well. There are several diseases where a host will be asymptomatic, but whoever they spread it to has symptoms. Mono, Herpes, and Menengitis to name a few.",
"Think of your body as a forest. Diseases happen when invasive new wildlife gets introduced to it. The wolves and foxes of your body don't know how to hunt them yet, and they don't have anything that limits their numbers. So they grow and multiply and eat way more food than the forest can support, tear up plants, poop everywhere, crowd out all their native competitors, etc. This is what being sick is.\n\nAnimals that carry diseases are the animals whose body's \"forests\" are their native home. They fit in there, don't disrupt anything, and get along with the species they evolved in harmony with.\n\nOver time, diseases introduced to humans tend to get weaker. Plagues are when things get so bad that the forest burns down as a result of all the disruption, and that's not good for the long term survival of the new germs. Those germs that evolve to live in harmony have more success, because they're not all dying with their hosts, either from the disease itself or from their host getting so weak something else can eat it.\n\nPast a certain point, evolving \"harmony\" no longer matters as much (or becomes a disadvantage), which is why the common cold never becomes truly harmonious, but plagues almost always dial back to something survivable over time.\n\nBasically, animals that are carriers are \"native\" ecosystems for germs, and those made sick are ones where they are \"invasive\" and disruptive."
]
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[],
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1ieque | divining rods | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1ieque/eli5_divining_rods/ | {
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"They're supposed to be tools that allow the user to detect water, or minerals or any of a million things under the ground.\n\nThey don't work."
]
} | [] | [] | [
[]
] | ||
2gsmj9 | if there are bigger stars than the sun, why is it that the brightest light we see is from the sun? and why isn't earth illuminated completely every hour of the day if there are stars big enough to engulf everything including the sun? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2gsmj9/eli5_if_there_are_bigger_stars_than_the_sun_why/ | {
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"If you have a 30W light bulb right in front of you and a 100W light bulb on the other side of the football field, the 30W bulb will appear *much* brighter because it's so close. By the time the 100W bulb's light gets to you, it's scattered so much that there's barely anything left to come straight at you.\n\nStars are the same way, only with much, much vaster distances between them."
]
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[]
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50rsjr | how is it possible for my exact speed to be accurately determined from a vehicle moving in the opposite direction? | Example: Speeding ticket issued by a police car traveling in the opposite direction. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/50rsjr/eli5_how_is_it_possible_for_my_exact_speed_to_be/ | {
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"It works the same as if the cop car was sitting still or moving in the same direction as you.\n\nThe math the allows the speed guns to work can handle all these scenarios as long as it can determine the relative speed and direction of the cop car. \n\nRemember radar uses electromagnetic waves which travel at the speed of light, so the speed gun can determine in less than the blink of an eye if he thing it's bouncing waves off is is getting closer or getting farther away. Once it knows that and the speed of the cop car, it tweaks the equation to match and can then determine the speed.\n\nAnd this is well before you even see the cop car in most cases. ",
"Basically because the radar gun is hooked into the speedometer of the cop car. The radar gun only returns *relative* speed, so the cop's speed plus your speed.\n\nHence, if the radar gun says you're going 120, and the cop was going 50 (which the radar gun knows because it'll be connected to it)... well, you must have been going 70!"
]
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[],
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] | |
8smqcj | is it legal for someone to secretly record a conversation with the president? why / why not? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8smqcj/eli5_is_it_legal_for_someone_to_secretly_record_a/ | {
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"That solely depends on where the conversation is taking place. Run into the president in the grocery store? Record away. Have a one on one conversation in the Oval Office? May want to ask first. It all has to do with the implication of privacy. Grocery stores are public places, and nobody has a right to privacy there. But a one on one conversation in a closed room can be considered an implication of privacy, where they have the right to assume they are speaking in confidence unless notified otherwise. "
]
} | [] | [] | [
[]
] | ||
66ymtu | how do games, like ones on the n64, with such limited capacity have loads of unused assets and levels hidden in the data? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/66ymtu/eli5_how_do_games_like_ones_on_the_n64_with_such/ | {
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"The programmers can't be certain that removing \"unused\" assets won't break the game. Adding or removing any content requires lots of QA testing to make sure nothing broke. Since there's no pressing need to remove that data, it usually stays \"on-disk\" in the final product.\n\nMaybe later, when the developer makes more content, they can call on that already present data to make their job a bit easier."
]
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[]
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230hbm | game of thrones. just the back story and all? | How did the seven kingdoms break apart from one another? What are the White Walkers? First People? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/230hbm/eli5_game_of_thrones_just_the_back_story_and_all/ | {
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"As far as background and backstory goes, you cannot do better than this video, narrated by the cast of the TV show _URL_0_\n\nAbsolutely the most comprehensive resource I've found."
]
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[
"https://www.youtube.com/watch?v=kPI_xA1SoRg"
]
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4d3b62 | why does microwaved food shrivel up, get hard and rubbery if you don't eat it right away? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4d3b62/eli5_why_does_microwaved_food_shrivel_up_get_hard/ | {
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"microwave ovens are basically enclosed chambers which emit microwaves on whatever you put in them. When you put food with water in it's liquid state, the microwaves basically cause the water molecules to excite and heat up. \n\n\nif you warm it up in the microwave and leave the water to just evaporate, the result is dehydrated food. but also because of the resulting heat from the hot water it also overcooks the food causing it to caramelize/burn and go rubbery.\n\n\nFun fact: because microwaves only excite water molecules in liquid state, it's possible to make a bowl from ice, fill it with water, put it in the microwave and the water will heat and boil before the ice melts...as long as the water doesn't melt the ice first. "
]
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[]
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3hmhv6 | why are the japanese not having children? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3hmhv6/eli5_why_are_the_japanese_not_having_children/ | {
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"Tricky answer because nobody knows. The crux seems to be that modern Japanese men are not interested in relationships. I have seen everything from internet culture to estrogenic compounds in their food (mostly soy and plastic packaging) blamed, but really nobody knows for sure. ",
"So it's a pretty common phenomenon that [as wealth rises fertility rates fall](_URL_0_). Lot's of rich countries have low fertility rates in the same neighborhood as Japan. \n\nThe overarching theory behind this relationship between wealth and fertility is that richer countries have more educated women with more economic opportunity (that often choose to delay childbirth) and that in especially poor families children are still seen as an economic investment. ",
"There are multiple explanations, which have been pointed out by other redditors, but I'd like to point out the economic factor.\n\nJapan's economy hasn't been great, wages have stagnated, and people are working more. \n\nMany people I personally know have started to get married, but they feel too financially limited due to pay vs. cost of living balance and have no plans to have kids (even if they would like to).\n\nThe two couples I know who have kids live with their parents, so at least they don't have to pay rent."
]
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[],
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"https://en.wikipedia.org/wiki/Demographic-economic_paradox"
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femvm8 | paradox and juxtaposition | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/femvm8/eli5_paradox_and_juxtaposition/ | {
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"juxtapostition is when two things are put next to each other to create an effect, normally showing how different they both are.",
"Paradoxes are when you have a situation that contradicts on itself. For example, \"This statement is a lie,\" is one. If it actually was a lie, then it wouldn't be a lie. But if it were true, then the statement would be lying to you.\n\nJuxtaposition is an artistic choice to put two things next to one another, to highlight the differences or similarities that they have. If a painting were to have a forest teeming with life, next to a factory polluting the sky, that would be an example of juxtaposition, as it shows the difference between the two situations."
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2cnnrw | if a vision impaired person were to practice shooting targets without wearing glasses and got good, would they become exponentially better with the glasses on? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2cnnrw/eli5_if_a_vision_impaired_person_were_to_practice/ | {
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"I would expect most visually impaired people would very much struggle with getting good absent their glasses. \n\nShooting isn't just about seeing the target, it's also about timing the natural motion of ones body and controlling every movement that can be controlled so the recoil does exactly the same thing each shot. ",
"I think it can really vary person to person. Just how severe is the impairment will all depend and what type of shooting.. \nIf this is long range rifle shooting with iron sights they might do just fine since you're sight picture of the target will be blurry anyway while your sights will be what you're focussing on. ",
"Nope. With modern sights, target shooting is more a matter of 'hold' and 'trigger control' than of visual acuity."
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8sbcwn | why aren't immigrant children who have been detained at the border being deported with their parents? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8sbcwn/eli5_why_arent_immigrant_children_who_have_been/ | {
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"Because neither have been deported yet. The parents are being held in holding facilities while they are processed and what country they are to be deported to is determined. The children are not allowed to be held in the same facilities and so are sent to different ones till their parents are deported, parents are allowed entry, or they can be given to other relatives either in or out of country. \n\nMany of the children also come alone and so cannot be released on their own if they are under age. These have to be placed with relatives or given over to foster parents. ",
"One reason is that the male and female adults accompanying child isn't necessarily the parents. Due to human trafficking, those can be human traffickers trying to sell those kids in the US.\n\nWhen my bring my kid back from international trip, I always have to pack a copy of her birth certificate just in case. These illegal immigrants aren't going to have papers.....cause they're trying to cross illegally."
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26ziwd | the class structure of bee and ant hives, particularly the queen. | I don't think I understand this topic very will, I'm sure others are in the same situation. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/26ziwd/eli5_the_class_structure_of_bee_and_ant_hives/ | {
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"I cant speak to ants but as a beekeeper I am familiar with them. There are three types of bees in the hive, the workers, the drones and the queen.\n\n The workers are all female and comprise most of the bees in the hive. As their name implies, they do almost all of the work. They forage, they build comb, they take care of the queen and the eggs. A worker can range up to roughly 2 miles in search for pollen. She can visit between 50-100 flowers on each trip, though in her lifetime she will only make about 1/12 of a teaspoon of honey. \n\n The drones are male, but don't do much -- their primary responsibility is doing the nasty with the queen. While it sounds like a nice gig, the drone dies after mating ([in a not very nice wa](_URL_0_)y!). Any drones in the hive at the start of winter are booted out. Less mouths to feed = a better chance of surviving winter. You never need to worry about being stung by a drone as they have no stingers. \n\nThe queen lays up to 1500 eggs per day. It takes 3 weeks for an egg to become a new worker bee. Her production can slow after 2-3 seasons and she might be replaced. Worker bees can make new queens by feeding larva a substance called royal jelly. The old queen will usually swarm about half of the worker bees before the new queen emerges from her cell. \n\n [Here](_URL_1_) is what the three types of bees look like.\n"
]
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"http://en.wikipedia.org/wiki/Drone_%28bee%29#Mating_and_the_drone_reproductive_organ",
"http://www.google.com/imgres?imgurl=http%3A%2F%2Fwww.oxfordshirebeekeepers.com%2Fuserimages%2FCastes.jpg&imgrefurl=http%3A%2F%2Ftcpermaculture.blogspot.com%2F2011%2F06%2Fintroduction-to-beekeeping.html&h=304&a... | |
81r4xv | what’s the difference between suntan lotion and sunscreen lotion | Title | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/81r4xv/eli5_whats_the_difference_between_suntan_lotion/ | {
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"Old \"suntan\" lotions - most of which don't call themselves that anymore - are sunscreens with a lower SPF (typically below 15SPF). The idea being that they would keep you from burning as quickly, whilst still allowing you to tan relatively naturally. They don't provide enough protection, however, to keep one from burning completely and should not be confused with higher SPF sunscreens"
]
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[]
] | |
28c38g | why don't countries with very large populations, like india or the u.s., consistently produce better soccer/football teams than smaller countries like the netherlands, italy and portugal, when they have a much larger talent pool to draw from? | Given that soccer isn't as popular in India, the U.S. and China, you would still think that they would statistically have an equal or greater number of capable players due to their populations. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/28c38g/eli5_why_dont_countries_with_very_large/ | {
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"In the Netherlands, Italy, and Portugal everyone plays soccer from a young age. In the United States there seems to be an early interest in soccer that wanes at pre-teen years. Then there is a lot more emphasis on football (American) and baseball. In India I believe cricket is similarly big.",
"If there's no attention then there's no money. Without money, there's no robust farming system, no ability to hire talent, and top coaches/trainers/assistants won't want to work here.",
"Everyone in India is too busy playing cricket. Everyone in the USA is busy playing basketball/baseball/American football."
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4jo4t3 | why a developing country like india have cheaper health care then developed country like america? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4jo4t3/eli5_why_a_developing_country_like_india_have/ | {
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"The economics of health care are complicated, especially when it comes to the United States, which has a rather unique position. Indians have less money, so demand is lower--prices must drop to accommodate this. On the other hand, the quality of care in India is also poorer, and fewer people have access to good care than in the U.S. \n\nAmericans subsidize much of the world's drugs, because Americans pay a high price and collective schemes in Europe purchase them below cost. Besides care being more expense, Americans use more care than others, so that total expenditures get quite high.\n\nThese trends are not iron rules, and aren't necessarily sustainable. For example, if reforms in the U.S. cause drug prices to lower, drug prices across Europe will go up.",
"America has by far the most expensive health care system in the world, with costs per operation approximately 10 times the average costs in other developed countries. This is because American health care lacks 'vertical integration'. Just like Walmart can undercut prices by controlling it's supply chain and providing massive bulk services from a central administration, government health care providers can too, negotiating better prices and saving on advertising, negotiation, insurance, etc.\n\nDeveloping nations services are even cheaper than other integrated health services for the same reasons. Wages for doctors and nurses are lower, rent is lower, and they can negotiate bulk drug purchases at cost or near cost, since it's better for a drug company to sell to Cambodia for a tiny profit than for none. These factors (cheaper labor, cheaper drugs, and cheaper land) make publicly administrated health care in developing nations affordable, if slightly less high quality.",
"1. Everything is cheaper in India than the US. There are in-depth economic reasons for this, but just know that it is the case either way\n2. Quality is lower (significantly lower in many cases)\n3. Overall, less healthcare services are consumed, thus lower total spending - someone struggling to scrape by isn't going to go pay to see a doctor just because they have a fever, while someone in the US who lives a comfortable middle-class lifestyle likely would.\n",
"A developed nations healthcare system will be more widely available, better organised and of a higher quality. Each of these costs more money to sustain than a worse system.\n\nThe US is a rather bad example because it's healthcare sector is so bloated which I would attribute to it's for-profit nature. \n\nA good and easy to understand explanation (imo) is here:\n\n_URL_0_\n\n\n\n\n",
"Because being in the medical business is useless if nobody can buy your medicine, they pretty much have to adapt to selling way cheaper than they would be able to do in another country if they want to be able to stay in business. They could try only having insanely expensive medicine and only treating the super rich, but I don't think the super rich are the people getting sick all to often.\n\nAdditionally from an American side: healthcare, liability, safety & testing, procedures, all of that tends to be of higher quality (and thus more expensive) than it is in India.",
"US has a private health insurance system that is profit driving, so that's a bad example and pretty obvious why it's more expensive. \n\nSo lets compare to European countries instead. \n\nSalaries of the hospital personell is more expensive in Europe, and drugs may also be cheaper (much of the cost of drugs is to cover research to develop the drugs, and therefore not really a cost per pill, just a total cost they need to cover up) because the developing countries simply wouldn't afford to buy the drug, selling it for a small profit is better than not at all (Not to mention they help saving lives that way). So it's easy to see that India can easily provide health care at a lower price.\n\nUnfortunately that's not the whole story, there are probably a ton of rare and/or chronical diseases that can be cured/treated, but for a huge price, that in Europe and US is in fact are treated - but not in India or other developing countries.\n\nThis is basically also why healthcare used to be much cheaper in developed countries 30 years ago - they simply weren't able to cure the same things as they are today. \n\nPerhaps it would be more efficient for the society to not spend money treating diseases that costs more per month than an average worker pays in taxes each month, but since it can be treated it would be a bit inhumane of the society to not do so."
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1f64s3 | why isn't russia a superpower in the world considering it's huge land mass? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1f64s3/eli5_why_isnt_russia_a_superpower_in_the_world/ | {
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"They have the most nukes, third highest military expenditure, are the 9th most populous, has had one of the fastest growing economies in the developed world over the last several years, they are geopolitical allies of just about everyone the US isnt...\n\nHow are they not a super power?",
"Superpower status comes from the ability and will to exert global power. Size of landmass is at best a crude proxy for a nation's power. ",
"Holy shit, look at Canada, right above the US! Do you see the size of that fucking thing? Now we know who the real superpowers are. \n\nThe second cold war is going to be way colder than the first. ",
"They are a superpower.",
"It's based on political influence on a world-wide scale not by land or population size. The U.S. is the only super power in the world but that's debated, many believe that the superpower status is non-existant and we now have several equal great powers.",
"They aren't really because they lost the Cold War. That sounds naive at first, but let me explain. During the Cold War, both nations not only had proxy wars, but fought for allies. They each offered weapons and aid to \"third world countries\" (essentially, countries not allied with either power). Once the United States won, the Russian government was forced to reform. They essentially had to come to a capitalist system. This meant that all the power that was held by the communist party essentially broke apart. They lost their international standing, much of their land, and lost a lot of their military.\n\nThe soviet economy was also forced on inefficient ways of production. People were forced to produce things in quotas rather than using supply and demand. Once the communist party lost power, this production basically had to be reinvented. They lost a lot of economic power.\n\nA lot of their allied nations also revolted and reformed. Eastern Europe went through massive revolution to become democratic (on the surface) today. They no longer ally themselves them.\n\nSince the United States became bigger and bigger after the fall of the Soviet Union, we invested more and more in our military. This meant that we became the dominant force for global power, meaning that we became the superpower.\n\nA lot of people have said that Russia is still a superpower, and this is somewhat true. Saying that, however, is kind of a misnomer because when you compare the power America wields to the power Russia has, we easily win out. Russia definitely has a strong amount of power in the world, but nothing like the United States.",
"A number of reasons, but the ELI5 version is because Russia is not very good at using that land mass productivelly. They do. They sell gas and oil and diamonds. However ten years ago or so a russian newspaper published an article about how Russian agriculture (nom, nom food) wasn't enough to provide for the entirety of the Russian population (many, many people). I'm sure that's fixed now, but it has never been a very effective \"clockwork\" (tick-tock), unlike the intra-extra connections between the states in US, as well as EU nations.\n\nThat being said, Russia *is* a political super power. Unlike US, however, it's not a media empire. Very few (none) russian films leave the Slavic nations. \n\nAnd I say all of this with love in my heart for Russia. They need to shape up."
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2b9qyi | how has india managed to largely resist the influence of islam? | Taking a look at the wikipedia article for religions in India (you know how wiki takes you places) I noticed that while Islam is the second largest religion practiced in India, that only amounts to 13.8% of the population.
It's India, so that's still a shit-ton of people, but I expected it to be much higher given India's geographic placement. It's bordered by at least 2 largely Muslim countries (Pakistan and Bangladesh)
ELI5. Why so few Muslims (relatively) in India? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2b9qyi/eli5_how_has_india_managed_to_largely_resist_the/ | {
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"Sorry to send you right back down the wiki rabbit hole, but you might want to check out [this page](_URL_0_) on the Partition of British India.\n\nBasically, the British Indian Empire was made up of the modern nations of India, Pakistan and Bangladesh. The split occurred mainly due to religious differences between Muslim Pakistan and Hindu India; if India and Pakistan had been one nation, the legislature would have been dominated by Hindus simply due to relative populations. With an independent Pakistan, the Muslim portion of British India could control its own destiny.\n\nEdit: I can't spell",
"Did you know [Bengladesh and Pakistan were created from India in 1947](_URL_0_)? Pakistan and \"East Pakistan\" (Bangladesh) were intended as Muslim states, while India would be Hindu. Mass migrations occurred after the new borders were drawn as the two religions moved to their respective states. The transition was violent and horribly managed. Maybe a million people died, estimates are uncertain. Based on today's population numbers within India's pre-Partition borders, Muslims are about 33% of the population.\n\nSo to answer your question, the Muslims did live in India and have made up a big part of its population for a thousand years. Britain split the country into Hindu and Muslim states.\n\nEdit: I can't stress just how important Islam has been in the history of the Indian subcontinent. The whole of India was ruled by the Mughal Dynasty, a Muslim empire, from the 16th to 19th centuries. It was, by some estimates, the 10th wealthiest empire in history.",
" > that only amounts to 13.8% of the population.\n\nThat's 13.8 percent of 1.237 billion people. That is 160,810,000.\n\nThe population of Pakistan is 179.2 million and Bangladesh is 154.7 million. Indonesia is the world's largest Muslim country, with a population of 252 million. \n\nAs you can see, India is the *third* largest Muslim country in the world and it has the world's largest Muslim minority population. \n\n > ELI5. Why so few Muslims (relatively) in India?\n\nThe Muslims in India are clustered in a few areas. Many left in 1947 when the chaos of partition happened. Jammu and Kashmir State in the very north of India has one of the largest populations of Muslims in India. \n\n_URL_0_"
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3g1r6x | why do people of foreign cultures take american names when they move here or come for education? | In my experience it is almost always East Asian people, for example my friend Weijun goes by Wilson. Wilson!? Weijun is way cooler. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3g1r6x/eli5_why_do_people_of_foreign_cultures_take/ | {
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"A lot of names are difficult for native English speakers to pronounce correctly. I imagine after a while having every person you meet totally butcher your name gets old and it's easier to just say \"Call me Bob.\"",
"I went to school with a middle eastern guy named Layath. People butchered his name alllllll the time. When he finished high school, he legally changed his name to Lawrence. It's easier to pronounce, and there is less of a stigma attached to a name like that.",
"Two things: Avoiding stigma associated with being foreign (Americans are, on the whole, reasonably tolerant of foreigners but there can still be discrimination) and avoiding frustration associated with people never pronouncing your name right and having a hard time spelling it."
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3kloii | what does the text in square brackets in newspaper articles mean? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3kloii/eli5_what_does_the_text_in_square_brackets_in/ | {
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"John: \"i said he was being ridiculous\"\n\n\nnewspaper article: John said \"[Michael] was being ridiculous.\"\n\nIt uses a word not used by the quoted person."
]
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zai10 | basic basketball strategy | inb4: "U PUT DA BALL IN HOOP N SCORE." -___-
Really.
What does an intelligently designed play look like? What would basic player positioning look like? How does a good player know which player to pass to? How does a good player know when to take the shot? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/zai10/eli5_basic_basketball_strategy/ | {
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"/r/NBA had an amazing contributor, /u/Mens_rea, who put together an excellent series on the fundamentals of basketball strategy. Check it out; it's pretty close to ELI5 level.\n\n_URL_0_"
]
} | [] | [] | [
[
"http://analyzetheoffense.blogspot.com/2012/06/mensrea-teaches-you-things-about.html"
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1hfxwp | when your voice 'breaks'. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1hfxwp/eli5when_your_voice_breaks/ | {
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"As part of your growth and development, as you go through puberty your larynx gets bigger and tilts forwards (giving boys their \"adam's apple\") and the vocal chords (note: no \"h\" in chords) within it increase in length and mass. Just like the strings on a piano or guitar, length and thickness are directly related to pitch. So as your vocal chords get bigger, the pitch gets lower when they vibrate. In some boys, the vocal chords do not grow at the same speed, so they may be of different sizes for a while. During that period, a pubescent boy's voice can sometimes jump unpredictably from high to low, giving the well-known \"voice cracking\" effect.\n\nThese vocal chords, also know as vocal folds, are dual strips of cartilage and other tissues in the voice box (also called the larynx). The vocal folds vibrate to produce the basic sounds that make up our voices.\nThe longer and thicker the vocal chords the lower pitched the sounds are. When we are born, boys’ and girls’ vocal folds are of similar lengths, measuring about 2 millimeters long, but they continue to grow as the child grows. Girl's vocal folds grow 0.4 mm in length each year, but boy's vocal folds grow 0.7 mm in length for the same time period – almost twice as much. This growth eventually slows down, leaving girls with a maximum vocal fold length of 10 mm and boys with a length of 16 mm. A longer vocal fold means a deeper voice, which is why males tend to have a deeper voice than girls.\n\nEdit:spelling."
]
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1z8nsk | how do i make money with original you tube videos? | If I post a video of myself falling down the stairs and 10 million people see it how to I get my check? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1z8nsk/eli5_how_do_i_make_money_with_original_you_tube/ | {
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"Once it becomes noteworthy, you will receive an alert that your account is now eligible for monetization. I got this when one of my videos managed to go viral and reach 80K views in a day. After setting up an Adsense account you use the Video Manager to select videos to monetize. They will feature ads, and you will collect ad revenue based on the *future* views and impressions generated by your video.\n\nIf you hit at least $100 USD you get a check in the mail from Google.",
"You can monetize any video from the get go with an Adsense account linked to your YouTube channel. Both of the other response are relics of a past system (before early 2013). ",
"[I recommend you try looking through youtube's account settings, as this is very clearly marked in there](_URL_0_)"
]
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"http://www.youtube.com/account_monetization"
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3fu4v6 | what does gate mean when it pertains to watergate, deflategate, penisgate? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3fu4v6/eli5_what_does_gate_mean_when_it_pertains_to/ | {
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"Watergate is the origin of the \"-gate\", there was a big scandal with Nixon were basically some files from DNC were stolen from the Watergate hotel. now people add \"-gate\" to try to compare it to that",
"Watergate was the name of the hotel in which Richard Nixon's cronies were found snooping on the Democrats (they were attempting to lay a recording device or something, I don't remember exact details.) So, the whole fiasco was penned the \"Watergate\" scandal by the media, and of course it went down in history as a hugely famous scandal. Since then, every large public scandal that's made headlines has been quickly named with a buzzword representing the case (deflate) with the \"-gate\" suffix added by the media, making it instantly recognizable as a major scandal. So yeah, the \"gate\" doesn't really mean anything, it's just more of a common media icon."
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20okev | eli12: what should a person look out for when buying headphones? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/20okev/eli12_what_should_a_person_look_out_for_when/ | {
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"If you are going to buy new headphones you want to go into a store and try on as many pairs as you can and narrow the list down from their, thinks to look for right away are comfort, sound quality, and what style you want (wireless one cord 2 cords). then after you have looked at all of those things you can look at looks. its important not to buy headphones purely based on looks. after you picked out a pair buy them and try listening to music for extended periods of time to see if they are still comfortable, if not return them and try another pair. best buy is a good store if you just want to go and try on a bunch of different brands. (good luck to ya:) )",
"[Sennheiser](_URL_0_). I would endorse anything they make, including the cheapest pair which is likely better than more expensive Beats branded ones. This brand is used by actual professionals, so you won't look like a trend chaser.\n\nIMO over the ear is always the way to go, despite how it makes you look like an alien or w/e. In ear and On ear both get uncomfortable eventually.",
"The built, the brand, and possible after-sales-support. I'd recommend Grado products, especially Grado SR-60i.",
"The problem with sound and headphones is that not all people listen to the same kind of music, have the same ears (both in hearing and aesthetics) or find the same style comfortable, so it's a bit hard to recommend. Reading specs won't help you much on figuring out how they will sound; aside of a general guidance, they won't be very useful.\n\nHere are some brands you can look into. They usually have wide range of options ($-wise) and manufacture high quality products:\n\n\nSennheiser\n\nAudio Technica\n\nShure\n\nAKG\n\nPioneer (High end)\n\nThere are some other brands that also have good headphones, but quality can vary and I can't vouch for them as I would for the ones above:\n\n\nPioneer (Low-Mid end)\n\nSony\n\nGrado\n\n\nIf you have any $ target I could help you a bit more."
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8f6cey | how do birds mate, and why can we still eat an egg? | I got asked this question the other day, and I cannot answer it.
I've watched a few documentaries which show birds dancing as a call for mating, but how does "mating" work?
Additionally, how is it possible we can eat an egg, if two birds have mated?
I never grew up in an environment where eggs and birds come together, so a bit of info on this would be educational for everybody.
Thank you for your time. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8f6cey/eli5how_do_birds_mate_and_why_can_we_still_eat_an/ | {
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"The chicken eggs in the grocery store have never come in contact with a rooster. They are unfertilized eggs. ",
"Hens lay eggs whether they are fertilized or not, and aside from the presence of the embryo, there's no difference between fertilized and unfertilized eggs. The eggs we buy in grocery stores are unfertilized but you can eat fertilized eggs too."
]
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2h5i8w | is taste an evolutionary adaptation, and if so, why do people living in the same area have such different taste preferences? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2h5i8w/eli5_is_taste_an_evolutionary_adaptation_and_if/ | {
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"Taste from the standpoint of being able to avoid spoiled or poisonous foods is obviously an evolutionary adaptation.\n\nRelatively minor differences in palettes between people are just individual variation."
]
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] | ||
491kzc | how did the wright brothers know how to land? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/491kzc/eli5how_did_the_wright_brothers_know_how_to_land/ | {
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"It turns out that you land whether you know how to or not. \n\nAnyway, the thing that makes them a part of history is the powered flight. Unpowered flight, which also required landings, had been around for a while. "
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218mio | atoms, how do they work? | Already tried AskScience, and I literally have not received a reply in 2 days so I thought I'd try here:
I understand what atoms are made of, Protons, Neutrons and Electrons, but what makes them so... Strong? If everything is made of atoms, why don't they mix together and just kind of form one big blob? For instance if I dropped a steel bar on a pillow, why wouldn't the atoms mix due to the forces? Does this mean they're basically the strongest things we know of? And also, if atoms are the smallest things we know of, what makes up the space between atoms? Is that literally nothing? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/218mio/eli5_atoms_how_do_they_work/ | {
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"Not only is there (pretty much) empty space between the atoms, but atoms themselves are pretty much empty space. There's a nucleus, made up of protons and neutrons, then vast amounts of nothing, then a sort of cloud of electron (not the neat little spherical balls in your science books -- that's just a helpful way of understanding it -- but fuzzy clouds of electron-ness).\n\nYou can actually smush atoms together into one big blob, but it takes a massive amount of force to do this. What you need is a star, significantly bigger than our own sun (at least 1.44 times as big), and then wait for it to use up all its fuel. It will then expand into a big \"red giant\", and then collapse.\n\nWith a star the size of our sun, the force of the collapse won't be great enough, and the star will become a \"white dwarf\" -- a small, dense star, but a star nevertheless, which will eventually die.\n\nBut a much bigger star... Well, if it collapses fast enough, the forces will be enough to smash the electron shells. The electrons -- which have a negative charge -- will fuse with the protons -- which have a positive charge -- and turn them into neutrons. Now there will be nothing stopping the neutrons from touching each other. As I said, atoms are mostly empty space, so the star would collapse into something just a few miles across, perhaps about the size of Brooklyn. This would be called a \"neutron star\", and it would be weird. It would have a shell of iron, but the centre would be pure neutron. One teaspoonful of pure neutron would weigh 900 times the Great Pyramid of Gizeh.\n\nIf the collapsing star is even more massive, it may actually smash the neutrons, which themselves are mostly empty space, and the star would collapse to almost nothing and become a black hole.\n\nSo if it takes that much energy -- the force of a collapsing star -- to smash an atom... why?\n\nWell, atoms are surrounded by a negative electrical charge, and we know that like charges repel each other. Atoms will tend to keep out of each others' way, the electron charges acting like fenders. You know how if you get two bar magnets and try to force the two south poles together? Like that.\n\nMost atoms, though, have unequal negative charges (in the electron cloud) and positive charges (in the nucleus), so will bond with other atoms to cancel out the charges, forming molecules, but still they don't smash each other's electron shells. Smashing electron shells takes, as I said, masses and masses of energy.\n\nThe electron cloud would like to escape the atom, but is attracted by the positive charge of the nucleus, so it gets stuck around the outside. Although electrons don't actually orbit the nucleus, it is a useful way to imagine it: the moon would like to fly off in a straight line, but is attracted by the earth and so is stuck in orbit around it.\n\nWhy don't all the positively-charged protons fly away from each other, since like charges repel? Because they're being held together by a much stronger force, called the \"strong interaction\" or \"strong nuclear force\". This force is much more powerful than gravity or electromagnetism -- far more powerful -- so it keeps the nucleus together; but it also falls off very, very quickly with distance, so it doesn't affect anything else.\n\nIncidentally, atoms are not the smallest things we know of. Even protons and neutrons are not the smallest things we know of: they're made up of quarks (three quarks make one proton or one neutron) and masses of empty space. It's not known what quarks are made of."
]
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2sk4iu | why is china building ghost towns in africa? who benefits from this? | _URL_0_
I searched for past topics here in ELI5 and saw some explanations about the ghost towns of China - that they are not that empty, and that the true empy ones are in the middle of nowhere, with no roads or ways to get a job.
But this one is right beside a big city, so it doesn't lack infrastructure, it is not far from jobs and it seems attractive to the people living nearby. But no one can afford it because their wages are low. This problem was pretty easy to predict, so why did China build it? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2sk4iu/eli5_why_is_china_building_ghost_towns_in_africa/ | {
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"Most likely because a local politician had gotten some 'funds' from ~~western~~ donors to develop their country or area. It's for prestige, and most likely some of the money found it's way towards the pockets of that politician.\n\nIt's sad, but it happens a lot.\n\nedit: it used to be mostly western donors, but that has changed."
]
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[]
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22gcg0 | why does nestea come in a 341ml can while carbonated coke products are 355ml? | Seriously, why? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/22gcg0/eli5why_does_nestea_come_in_a_341ml_can_while/ | {
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"It could be a variety of factors, we can never be sure.\n\n- To get a nice, rounded, amount of \"something\" in the Nutritional Information.\n\n- Because the design of the bottle amounted to that and they said \"well, that's close enough\".\n\n- So people would ask \"why is it 341 instead of 355?\", marketing. Hey, we're talking about Nestea, it worked.",
"The primary reason this sort of sizing is becoming more common is to adjust the shipping dimensions of a product to be more efficiently packed for distribution. That size difference likely makes for more product overall in a truck."
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2l1dtx | what is that awkward, hanging feeling of reality you get sometimes? | It's randoms sometimes. You're going on about your day, and your feelings just drop. You realize what you are, and the concept of reality. But sometime's its with interactions with other people. Or being around them. You feel strange, you want to close your eyes, wanting to be somewhere else, it's almost as if you just can't accept reality. But I really don't know..
But that's why I posted that here. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2l1dtx/eli5_what_is_that_awkward_hanging_feeling_of/ | {
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"text": [
"Sounds to me like you were having a momentary existential crisis. I get them a lot.\n\n_URL_0_"
]
} | [] | [] | [
[
"http://en.m.wikipedia.org/wiki/Existential_crisis"
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9239r7 | why do foods with higher fat content taste better? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9239r7/eli5_why_do_foods_with_higher_fat_content_taste/ | {
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"Fat is calorie-dense, and for the vast, vast majority of human civilization, starvation was a significant concern. Therefore, your body wants you to eat calorie-dense things to not starve to death, thus it's adapted to find those things tasty.",
"Foods with higher fat content are full of lipids, basically just long carbon chains with a few differences. Hydrogenated, sometimes not, etc. However you have to realize that 20,000 years ago humans were not able to put food in their belly consistently. They had to live for days without food. When they did find food, they had to eat as much as possible to survive. Because of this, humans evolved to eat as many lipids as possible as possible. It’s remarkable how this occurred. The ones who had genes that made fat taste good went on to survive and reproduce. The ones who did not enjoy fat, likely died of starvation, sickness, or other lack-of-food illnesses. \n\nThat’s why something like a donut or ice cream or cake tastes so good. These things are concentrated fat and sugar (sugar works the same way). It’s an unnatural drug for our body. ",
"Our bodies are wired to crave things that we need that are in short supply. Our body needs fat, but until very recently in human evolution, fat was in very short supply. So, our body tells us to eat the fat when we find it, because it probably won't still be there in an hour.\n\nOf course, we don't have that fat scarcity anymore, but evolution moves much slower than technology."
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1ssw31 | what's the big deal with north korea executing kim jung un's uncle, jang song thaek? why haven't we heard of him before? who was he and why was he killed? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1ssw31/eli5_whats_the_big_deal_with_north_korea/ | {
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"He was one of the most important leaders in the North Korean government for some time. While his exact position is unknown its suspected that he was leading the country while Kim Jong-il was ill and helped Kim Jong-un through the transition process. He was considered to be China's point man into the country and the Chinese considered him a voice of reason in a country that is known for going off the deep end. You don't know about him because he worked behind the scenes and was never a public face for the media. \n\nNobody actually knows why he was killed but they suspect that Kim Jong-un is purging the leadership of the country in order to ensure his power. Executing such a high level figure publicly is something that simply does not happen often in North Korea so this is a very shocking event. "
]
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66q6g6 | why aren't metropolitan transit services (such as subways, commuter rail, and amtrak) privatized in the u.s.? put another way, why does the u.s. lag behind the rest of the world in providing reliable, high-speed transit services? | Facing another rash of horrendous travel delays in the NYC area today, it begs the question, why are these services provided by the government, or heavily subsidized in the case of Amtrak, and not privatized? Would privatization help?
Why does the U.S. lag behind the rest of the developed world (especially Japan, for instance) in providing reliable, high-speed transit services, especially in the densely populated Northeast corridor?
Not trying to get political. Thanks! | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/66q6g6/eli5_why_arent_metropolitan_transit_services_such/ | {
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"The US has a huge driving culture, that's the simple enough reason. \n\nThat makes it really difficult to live in a lot of places without a car. There may be transit from A to B, but you might need a car to get from your home to A, or from B to your workplace.\n\nCar culture is a self-catalyzing thing. The more your culture is about owning and driving your car, the more you need a car (because cars and parking and roads take up a lot of space, meaning you need a car to go longer distances).",
"Subways don't lend themselves well to privatization because they depend completely on city-owned rights of way -- that is, they are underneath the streets.\n\nAs for other rail service... Amtrak exists because privatized rail service was failing. Even with its subsidies, Amtrak offers an alternative to air travel that is slower and more expensive, except for places like the Northeast, with large cities closely packed together.\n\nIt's really hard for a private company to want to enter a market where their competition can already do it faster and cheaper.",
"They were for a long time... in most cities I think you'll find there were private mass transit companies (some specializing in specific routes, others offering general service) from the 19th century up to the mid-20th century (1940s to 1970s). What usually happened is they went bankrupt, stopped operations, or it was clear they were on that path, so the city took over.\n\nWhy that happened is somewhat controversial. I know in my city of Louisville there was no sweeping conspiracy, ridership levels just fell over time to the point where the company announced it was no longer profitable so it would cease operations. It was basic economics... as people became more spread out, and preferred cars, it wasn't so profitable to run a bus down a 9-mile loop picking up people who wanted a ride. The density was way down and popular destinations like shopping centers, apartment complexes and major employers were being built with only car access in mind. If you ran a bus company today without any government subsidization, a ticket would cost like $7-10 and few people would want to pay that. \n\nThere is also a theory that car companies accelerated or entirely engineered this process: \n\n_URL_0_",
"There is nearly no benefit to privatizing public transit. It takes too much money to build and run. We know this from experience because the US used to have those services privatized. They started to fail and so cities either took them over completely or started to subsidize them. \n\nYou cannot make enough money with them for profit and keep the costs low enough for customers to use them while maintaining them at the same time. Because you cannot profit from them there is no incentive for a private company to attempt to do them anymore. ",
" > Why does the U.S. lag behind the rest of the developed world (especially Japan, for instance) in providing reliable, high-speed transit services, especially in the densely populated Northeast corridor?\n\nThe answer is both geographic and political. \n\nThe geographic answer is that Japan has just under 130 milliion people living in an area similar in size to California. The US' population density is [182nd out of 246 States and Territories](_URL_2_). While it has more densely populated regions (like California and the I-95 corridor), the most [densely populated state](_URL_1_) would only be 25th on the list (and New York State would be the 150th well below most developed nations). \n\nThat low density (even in our relatively dense regions) means a given length of transit crosses fewer people's paths, making the average cost per rider higher than in most nations. \n\nFurther there are political problems. The US was designed to be a federation of states. To achive this federation, smaller states had a justifiable concern that they would be dominated by the large, high population states. So the compromise to get all of them to join, reserved significant political power for the smaller states (and many states do something similar for their smaller, less populated regions). As a result of this political power, it's difficult to spend lots of money on transit for the dense regions that ignores the lower population regions, so either you spend a ton building mass transit to places that don't have the population to justify it (high costs and low usage that makes projects a boondoggle) or projects are hard to justify at the state level (because those city folks want to spend all our state money on projects that only benefit them). \n\nSpecific to Japan, geography means that a large proportion of the people live in [two rough bands of population](_URL_0_), so two railroad lines that go up along each coast of the nation, plus a few interconnections between the two create a network that covers an enormous proportion of the population of Japan. That means the average cost of a high speed rail ticket in Japan can be significantly lower than in the US. ",
"Also, privatizing doesn't allways help when you create a monopoly. It's not like you can choose which subway company you want to ride on depending on services provided.\nI live in Spain and the train company was privatized some years ago, the train tends to be more expensive than the plain and there isn't much you can do about it."
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"https://en.wikipedia.org/wiki/List_of_countries_and_... | |
726fby | why do horses willingly fight wars/battles for humans? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/726fby/eli5_why_do_horses_willingly_fight_warsbattles/ | {
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"Same reason they let people ride them, pull wagons, and plow fields for humans\n\nThey were domesticated and trained to do so.\n\nA war horse simply receives different training than a farm horse. Instead of practicing pulling a heavy load, it practices being ridden with a heavy rider with lots of noise going on around it. After a while it doesn't mind the noise so much, it knows its going to go back to a stable and get fed and brushed after its all over so it does what its told. After its been well trained in practice then you can bring it onto a field where it might not get to go back to a stable at the end of the day, if you trained properly then it won't realize the difference until its too late.",
"Cavalry horses are carefully selected for courage and obedience, and are trained with loud noises and frightening sights to prepare them. \n\nOn top of this, once a horse forms a deep bond with its rider, it will trust the rider and be willing to follow commands even when they seem dangerous. And horses are herd animals by nature--once they see the herd charging into battle, they feel pressured to charge with it."
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aoe6gc | why does smoke look different after inhaling? | Like if I hold the smoke in my mouth, when I push it out it looks different than when I blow it out after inhaling. Idk if that makes sense. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/aoe6gc/eli5_why_does_smoke_look_different_after_inhaling/ | {
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"Some of the particles dissipate inside your lungs making it less thick.\n\nIf you're looking for a scientific explanation in detail I can provide that as well.",
"If you inhale the smoke, the lungs filter it before you exhale.\nA nice trick a teacher once showed me.\nTake 2 tissues.\nInhale the smoke and the exhale with the 1 tissue covering your mouth.\nThen don't inhale and keep the smoke in your mouth, and push it out through the 2nd tissue.\nYou should see a significant difference.\n"
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80c9lr | how does hrt affect muscle mass and bone density in trans women? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/80c9lr/eli5_how_does_hrt_affect_muscle_mass_and_bone/ | {
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"In general, undergoing HRT causes trans women to have an increased BMI, which involves both a reduction in muscle mass and an increase in stored body fat. The body fat is mostly gained in more \"feminine\" areas. \n\nAccording to [this study ](_URL_0_), there is no increased risk of osteoporosis (i.e. lower bone density) as long as estrogen is being taken. These days it is extremely rare for trans women to be prescribed a testosterone blocker without an accompanying estrogen. "
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a1l9rl | does air itself have a volume ? | Does air itself (outside a container) have an innate volume ? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/a1l9rl/eli5_does_air_itself_have_a_volume/ | {
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"Yup! All matter takes up space. Air outside of a container is just in the really big container that is the earth’s atmosphere. It’s harder to breath at higher elevations because the air is taking up more volume per particle of air, and there’s less oxygen around to breath. That’s also why if you run forwards while holding a trash bag open behind you, it will fill up. The air that was free in the atmosphere is trapped in the bag, and takes up the same volume it did before when it was free.",
"Yes, air is made up of several gases and those gases certainly have a volume. You can take an amount of air and compress it so it takes up less volume. ",
"No, like all gases, air will expand to fill whatever volume you put it into, without limit. You can put a gram of air into a small container or a huge one, equally well.",
"Yes — there are individual gas molecules in ‘air’ — roughly 78% is nitrogen, roughly 20.5% of it is oxygen. The molecules have a volume— each of them is obviously very small, but it has a size, and a weight. The volume is dependent upon pressure when air is in a gaseous state, though. ",
"When you say “air” you probably refer to the - invisible - air around you. But that air actually consists of a number of different invisible particles, all very small and light and floating around. You can actually feel them when you wave your hand, so they’re definitely there. \n\nIt’s almost like water, but even easier to move around in. \n\nAll these particles take up space, thus volume. But since they are so light and move around freely, they can take up less, or more, space based on how many you try to put together.\n\nImagine when you fill up a balloon, you are actually blowing many of these particles into a confined space (the balloon). They occupied more space/volume before than they do now you’ve filled the balloon. Note how it takes effort to blow up a balloon. That’s because it takes energy to compress air. When you pop the balloon, the energy is released with a bang, because the particles forcefully take up their original space. ",
"It depend what you mean. Air is made of molecule and atoms and there is something we call atomic radius, which is the measure between the centre of the nucleus and the boundary of the electrons cloud. Technically speaking with this radius you can calculate the volume of that element, but that wouldn't be that useful.\n\nOther than that, no gas doesn't have an objective or innate volume. The element and atoms of a gas are not linked between them, so they will spread as much as they are allowed to. Technically there is molecule of hydrogen spread across the universe.\n\nThe volume of the atmosphere is limited by gravity that keep the air from spreading across space. But that volume is determined by the balance between the outward pressure of the gas (air) and the gravity.",
"Well, yes. Air, like any other gas, will expand to fill out any container it is put into. Container can be a balloon, a metal canister (like divers use), or an entire planet. The interesting thing is, you can squeeze the air into smaller containers, by applying pressure on it. So, volume can be varied.\n\n",
"I have a 1L bottle of air that I open and I look how the volume evolves over time:\n\nAt t = 0 the volume is 1L.\n\nAt t =1ns the air is still mostly there. Since nothing can travel faster than the speed of light the physical space where a particle of this air could possibly be is less than 1m^(3).\n\nAt t = 1h the air is mixed with part of the atmosphere but probably it's still mostly around there.\n\nAt t = 10 years the air is very mixed so now it's spread over the whole atmosphere.\n\nI can't think of a definition of volume which is consistent over all this timeline yet it's an innate poperty of air.\n\nOn the other hand I can just define an imaginary volume of 1L that happens to contain air and it doesn't even matter whether this air is always the same or not.",
"The ideal gas law states that any 1 mole of air (which is avagadro's # of molecules) will occupy 22.4m\\^3 at standard temperature and pressure.\n\n & #x200B;\n\nso yes. It's volume is 22.4 cubic meters/kmol at STP.\n\n & #x200B;\n\nRegards,\n\nJW"
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dbn865 | finding the inverse of a number with (mod n)? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/dbn865/eli5_finding_the_inverse_of_a_number_with_mod_n/ | {
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"First, a number x can only have an inverse (mod n) if that number and n are coprime, i.e., they don't have any common factors. In other words, gcd(x, n) = 1.\n\nWe can use the [Extended Euclidean Algorithm](_URL_0_), which extends Euclid's algorithm for finding the GCD of two numbers, to find the inverse of x (mod n). In Euclid's algorithm, the divisors in one step become the dividends in the next. That link is used in the extended algorithm to express the GCD as a linear combination of the two original numbers (x and n).\n\nLet's say we want to find the inverse of 17 (mod 39):\n\n1. First, we find the GCD using the Euclidean algorithm\n 1. 39 = 2 × 17 + 5\n 2. 17 = 3 × 5 + 2\n 3. 5 = 2 × 2 + 1\n2. Therefore the gcd = 1, which means that 17 does have an inverse (mod 39)\n3. To help with the extended algorithm, we rewrite the above progression of equations such that the remainders are written in terms of the dividends and divisors:\n 1. 5 = 39 - 2 × 17\n 2. 2 = 17 - 3 × 5\n 3. 1 = 5 - 2 × 2\n4. Now, for the extended algorithm, we work our way upwards, starting with the last equation 3.3 above, replacing the divisor with its equivalent expression as a dividend in the equation above, so that we get an equation in the form of 1 = 39*P* \\+ 17*Q*\n 1. 1 = 5 - 2 × 2 (from 3.3)\n 2. 1 = 5 - 2 × (17 - 3 × 5) (from 3.2)\n 3. Simplify and then group the 5's: \n1 = 5 - (2 × 17) + (6 × 5) \n1 = 7 × 5 - 2 × 17\n 4. Notice how the above equation has now been written as 1 = 5*A* \\+ 17*B*, and the 2 has been eliminated. The same process will be recursively applied until the desired form is reached\n 5. 1 = -2 × 17 + 7 × 5 (from 4.3)\n 6. 1 = -2 × 17 + 7 × (39 - 2 × 17) (from 3.1)\n 7. 1 = -2 × 17 + 7 × 39 - 14 × 17\n 8. 1 = -16 × 17 + 7 × 39\n 9. In other words1 = -16 × 17 (mod 39)\n 10. That means that -16 is the inverse of 17 (mod 39). If we want a number between 0 and 38, just add/subtract 39 as necessary:\n 11. \\-16 = -16 + 39 (mod 39)-16 = 23 (mod 39)\n 12. Therefore,17^(-1) = 23 (mod 39)\n\nThis can be verified, by simply multiplying the two and checking the remainder:\n\n17 × 23 = 391 = 10 × 39 + 1"
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10ramt | why are there 720p movies of 750mb and 5.5gb if the 750 looks seemingly as good as the 5.5gb? what's the difference? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/10ramt/eli5_why_are_there_720p_movies_of_750mb_and_55gb/ | {
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"The difference is simply in high how the bit-rate is. This is why 720p occasionally looks better than 1080p. More bit-rate means more detail up until a certain point where it is redundant.\nIt's alot like mp3 in a way. All standard mp3 files have the same amount of frequencies that can be played back, though how much detail is allocated to each part depends on the bit-rate.\nAt around 320kb/s theres no concievable difference between the lossless and the lossy compressed one (mp3)",
"Video compression works by throwing things out. The trick is to only throw out the bits that you won't miss. There are lots and lots of settings that determine what gets thrown out and when. If you use transcoding software like handbrake with the default settings, the converted video will look good, but it won't be all that small. You can start playing around with these settings, but unless you know what you're doing, the video may come out even bigger or it might look bad. It takes practice and effort to know what to change for what types of movies.\n\nTo get *really* small (under 1.5GB) 720p rips that actually look good, you need to adjust these settings not just for the whole film, but from scene to scene. This requires a lot of work, and getting it right is almost an art. But no matter how good someone is at it, the h.264 codec is still not perfect and you're still throwing things out to make the video small. Some people are more sensitive to the distortions caused by this extra compression. You may not notice the difference (or at least not enough to ruin the experience), but others might. So between the effort involved and some people still not liking these super-compressed rips, they're not very common.\n\nBut there is hope. The Motion Picture Experts Group (MPEG) has [recently finalized the specifications](_URL_0_) for a new, better compression scheme called h.265. It is said to be twice as efficient as the current popular codec, so in the future, visually-identical 720p videos can really be half the size they are now without all the effort that is currently required.",
"Uncompressed video is extremely big. So outside of working in video editing, all video you have is compressed in some way. Data compression can roughly be divided into two categories. There's the lossless compression and the lossy compression.\n\nLossless compression is compression where you get exactly the original content after you uncompress the data. If you compress any program files, they will be compressed using a lossless compression because even the slightest difference in a program file will cause the program to malfunction. \n\nLossy compression is compression where you accept that after uncompressing the file, the result may not be exactly what it was before. This is fine for things like video and audio where people probably won't notice if there is a tiny difference to the original. We're talking things like the shade red at some small part of the screen being a bit wrong. In general, you can compress things much more with lossy compression so pretty much all video is compressed with it. Lossless compression simply doesn't compress the video enough.\n\nOne obvious thing that affects the file size and quality is bitrate. It's how many bits of data there is per one second of video. If you can have more bits per second of video then you can include more details in the picture. So maybe the 5.5 GB file had a much bigger bitrate. But that's not the only thing that affects quality and file size.\n\nOften with compression, especially lossy compression, there isn't one correct way to do it. Even if the file type is the same and the codec is the same and the bitrate is the same, you can get two very different files from the same source material. The encoder that does the compression does some guesswork in what details it can throw away from the picture in order to get a better compression ratio but without affecting the resulting picture too much. Different encoders may very well do this differently. In general, the encoders also have a lot of settings that the user may fine tune. So if you have a bad encoder or one where the settings aren't tweaked very well then it may need to use a much higher bitrate in order to achieve a similar quality. \n",
"The 5.5 gig version will likely have better fine texture, especially in scenes with a lot of movement. It's not so noticeable while watching but becomes much more obvious if you pause.\n\nIt's a bit like how [adjusting jpeg compression works](_URL_0_), the smaller file (rightmost image) looks roughly the same, but if you look closer it's a lot smoother than the larger files because compression removes fine details.",
"I'm sorry, but almost no 750 MB 720p rip look as good as a 5.5 GB rip, assuming you're talking about a normal, live action, 2 hour movie. Honestly, 750 MB isn't even enough to make an SD rip look very great.\n\nVideo compression works by taking advantage of temporal redundancies (each frame looks very similar to the ones immediately before it) and by getting rid of spatial details humans don't notice easily. An uncompressed 720p movie takes up 530311 kbps for just the video. Video compression is amazingly efficient, and for a typical movie, that can be brought down to 4000-10000 and still appear almost identical to the uncompressed original.\n\nHowever, at that 750 MB file size, you're looking at bitrates of 700-900 kbps. For 720p, that means throwing away *tons* of high frequency details. The picture appears smoothed, natural grain in the original becomes dancing distortion, and you're only saved from terrible blocking by the deblocking filter (meaning further smoothing). It's still watchable; you can still tell what's happening, but you're not really getting an HD picture by any standard other than the resolution. It's probably even worse quality than watching an upscaled properly made SD rip.",
"\"Seemingly\" being the key word. Your eyes, your screen, the light in the room -- it all affects how you perceive the quality of the video. Remember, most video encoders are freakishly adept at removing the things you don't \"see.\" So, it's only natural that you say \"hey, this looks pretty good.\" \n\nHowever, were you to buy a good TV or monitor, and sit close to it in a dimly lit room, and freeze one fast-moving frame, I guarantee you that you would see a significant difference.",
"All good points so far, but it helps to consider the entire end-to-end of encoding. Specifically:\n\nSource quality + resolution - > Encoding algorithm - > Encoder settings - > Output bitrate + resolution\n\nA high quality source means generally less \"noise\" and a more efficient encode. Source resolution determines the number of pixels, which gives a crisper/larger picture but increases filesize.\n\nThe encoding algorithm determines, generally speaking, how efficient the encoding is. Generally speaking, more modern encoders are more efficient/smarter than older encoders.\n\nThe settings on the encoder also affect the efficiency of the encoding - these are the expertise that the user puts in, and can cause a large amount of difference.\n\nThe output bitrate and resolution both directly affect the filesize, and together the quality (lower resolution + higher bitrate = higher quality picture, for example).\n\nThus you can see there are a number of contributing factors - a smaller size rip might look better if the larger size rip uses an old encoder, poor settings, and has poor source material. However, if you have good source, good encoding, high bitrate etc, you're going to typically end up with a largeish file that looks awesome.",
"One method of reducing size while maintaining quality is keeping the Green channel at the highest resolution while reducing Red and Blue. For your eyes green is easier to see details and is more \"contrasty\".",
"Another point I don't see mentioned yet: Your ability to compress depends greatly on how active the picture is.\n\nIf your film is full of long, slow scenes with little camera motion, it'll compress *vastly* smaller than a full on action movie with shit exploding and flying everywhere. \n\nMotion, activity, changing shapes and colors cost a lot more bits than a static image. So does fine detail. This is why cartoons like South Park or Family Guy compress so ridiculously small compared to live action. It's also why action movies are often so much larger than dramas.",
"Sound data is another big factor, in addition to the very good posts about video data and compression. Some movie rips only include MP3 stereo sound, which usually has bitrate of 160 to 320 kilobits per second. The resulting stream only occupies around **150 to 250 megabytes of sound data** in the video container. But some movie rips include multichannel surround sound (e.g. 5.1 Dolby Digital, 6.1 DTS, 7.1 Dolby Digital Plus, etc.) which is compressed using the Dolby AC3 audio codec, which is less efficient than MP3. This results in a bitrate of [640 to 18,000 kilobits per second](_URL_0_), which can then occupy **500 to many thousands of megabytes of sound data** in the video container.",
"Imagine you wanted to tell someone over the phone exactly how to draw a picture of a checkerboard you're looking at. You can tell them the basic pattern and the angle and distance the board is at, and they'll do a pretty good job of making a picture that looks REALLY similar to the one you're staring at... and it didn't take much time to get the info across. But now suppose you want them to be really exact and to get all the tiny paint variations and specks of dust on the board in the same space. You are going to have to talk on the phone for a LOT longer to tell them where to draw those, and they really won't make much difference in the end. \n\nIt's the same idea in compression, just with a lot fancier math. The \"big picture\" you see has a lot of structure to it, so you can communicate it quickly. But the tiny details are usually not as ordered and you have to start specifying them at a more individual level.",
"I have an additional, related question. So, when I go to download a movie, there are 720p and 1080p rips of various sizes in the .mkv format; the 720's are often around 4 or 5GB and the 1080's are often around 6, 8, or 10GB. These both look really great on my monitor, but they eat HD space. But then I get these files that are .mp4 format around 1 or 2 GB each, and they only look slightly worse than the HD rips. Why is that? What is so special about the .mp4 format?",
"I was actually on the encoding group that introduced mHD (micro-HD) rips. We took 720p sources and sized them down. We had a chart that we went off of. If the movie was less than 90 minutes, we shrunk it to 1099mb, if it was 91-120 minutes, we used 1466mb, and so on.\n\nBasically you can reduce the quality to a certain point before it really gets noticed. We would take a lot of the quality out of the audio tracks because unless the viewer had a multi-thousand dollar sound system, they wouldn't be able to tell the difference.\n\nSo basically, deleting as much as you can without it being noticed.\n\nNever did we get a 750mb rip that looked as good as the original 4gb 720p source, but we could consistently take 4gb 720p rips and convert them to anywhere from 1099mb to 2199mb (depending on length of the film) and have the quality be damn near identical.",
"These answers are really great, but I think they are missing the spirit of this subreddit. Or they know some fucking smart 5th graders.",
"The small ones don't look as good. If you know what to look for you will see the compression. A transparent 720p encode will be about 6gigs for an average length movie. A transparent encode of a 1080p film should run about 10gigs. That's with DTS audio. Some of the smaller rips may toss out the DTS audio. \n\nThe most obvious compression artifacts will be in the dark areas of the film. These are the areas which suffer the most due to the way the algorithms work. Look for swirling or waving patterns in the grain. To me, they are very distracting because I know what they are.",
"Have you been pirating movies, Charles?",
"720p is a HD resolution. 1280 horizontal x 720 vertical lines of resolution. Within that \"pixel map\", how much information per second (frame rate and bit rate) you're gonna get is the difference between a 750 MB and a 5.5G movie. \nThere are many many different codecs offering low to high bit rates, and the number of frames per second is also a factor in the size of the file, and the quality of a movie.\nOn a small computer screen, you won't see much of a difference. On a 32\" you will notice clear differences, and on a projection screen or very large plasma screen, your 720p movie of 750 MB will look awful.\nIn professional/corporate environments, the codec Apple Pro res 4:2:2 for Quicktime is very often used because it is absolutely stunning. Let's say a 10 mn 720p video @ 29.97 fps would have a data rate between 100 to 150 Mbps and probably be around 4Gigs. ",
"The 5.5gb movies you see are made by Release Groups, They follow Rules which have been agreed upon by these groups, They release it for amongst themselves but it always gets leaked to the clearnet but anyway i will leave out irrelevant information.\n\nThese are the rules for x264 Movies,\n_URL_0_\n\nThey state (7.1) that \"Final mkv file size in MiB (1048576 bytes) must be:\n\n 7.1) Final mkv file size in MiB (1048576 bytes) must be:\n Multiples of 1120\n DVD5/x (896, 1493, 2240, etc.)\n Also allowed 2713, 8140 for all releases and 4070 for 1080p tv.\"\n\nI cannot really explain this part to you, maybe someone with better technical knowledge can explain, but these are the rules. These releases are for archives, for traders and for people with direct axx to these releases, not for people who download it off file hosters or private torrent sites although they are 99.995% of the audience.\n\n\nAs a result of this, \n\n* A 720p movie with 02:04:40 runtime will be 5600mb.\n\n* A 720p movie with 01:45:24 runtime will be 4480mb.\n\n* A 1080p movie with 02:20:02 runtime will be 11200mb.\n\n* A 1080p movie with 02:16:14.258 runtime will be 10066.58 MB\n\netc etc.\n\nThis is the only answer you have been looking for, i wish i can explain it to you like you was five, I don't see anyone else here knowing about the scene, all they could give is info about compression of x264 codecs etc, although i am not saying they are wrong, they don't know anything about why the movies are around 5.5gb.\n\n\n**TLDR; 5.5GB Movies are that size because of rules set by scene groups amongst each other, As a result of that, the movie you are talking about is probably 720p in quality, around 1 hours 14 minutes in runtime. They are not these sizes for optimum filesize but because these are the rules.**\n\n\n\n",
"Damn it I love YIFI's releases.",
"ELI5: your question"
]
} | [] | [] | [
[],
[
"http://www.engadget.com/2012/08/15/mpeg-drafts-twice-as-efficient-h-265-video-standard/"
],
[],
[
"http://www.uxbooth.com/wordpress/wp-content/uploads/2009/07/image-optimization/image-compression-quality-comparison.jpg"
],
[],
[],
[],
[],
[],
[
"http://en.wikipedia.org/wiki/... | ||
39y3e5 | why does flying from, say, seattle to calgary through vancouver cost less than flying from vancouver to calgary | Something that I've thought about for a while but have never been able to understand.
4 years go I flew from Seattle to Calgary through Vancouver. At the time I considered bussing to Vancouver and flying to Calgary, but the flight from Vancouver to Calgary actually cost more than the flight from Seattle to Calgary (through Vancouver).
I fly semi frequently and have seen this time and time again. Why? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/39y3e5/eli5_why_does_flying_from_say_seattle_to_calgary/ | {
"a_id": [
"cs7hgvo"
],
"score": [
3
],
"text": [
"Flights are mostly priced on demand, not cost. Nonstop flights are almost always the most expensive option because they are the most demanded. They fill up quickly with business passengers that are willing to pay more for the convenience of saving time. "
]
} | [] | [] | [
[]
] | |
1y2rwn | how does a burnout work? | Considering the friction between tire and road, and tire and rim: Shouldn't the rim rotate within the tire? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1y2rwn/eli5_how_does_a_burnout_work/ | {
"a_id": [
"cfgu59k"
],
"score": [
2
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"text": [
"The rim would not rotate within the tire because the bead of the tire creates a seal with the rim, then once the tire is inflated it creates enough friction to keep them spinning at the same rotational velocity. The tires, and rim, are able to spin freely over the road during a burnout because the tire is spinning fast enough that it does not grip the road (like when you slide over ice, the tire is unable to grip the road)"
]
} | [] | [] | [
[]
] | |
1z9imx | would cleaning my teeth for an hour effectively whiten my teeth? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1z9imx/eli5_would_cleaning_my_teeth_for_an_hour/ | {
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"cfrpbbl",
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"score": [
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"text": [
"From my understanding, no it will not. Toothpaste is abrasive and brushing your teeth for hours at a time will eventually wear down your enamel. In fact, it will make your teeth yellow because of the enamel deterioration.\n\nYour teeth a porous to an extent, and are stained because they slowly take in the colors of food, drinks, and smoke. \n\nSource: I read an article somewhere about a month ago. I in no way can say any of this is %100 true.",
"No. Dentine is pale yellow, enamel is white, but enamel is also translucent. Brushing with toothpaste may remove stains from coffee and red wine but also may wear away at the enamel, making your teeth look more yellow. Bleaching can make your teeth look more white but it also can damage them, so pale yellow teeth are actually stronger than white teeth. [Source](_URL_0_)\n\nUse a soft toothbrush, a good sodium fluoride or stannous fluoride toothpaste, and rinse after coffee/soda. Don't brush your teeth within 30 mins of food or drink consumption. \n\nEdited for clarification. ",
"No, it would damage your teeth.",
"No, it will stain them red as your gums get shredded and bleed all over. Enjoy that image for the rest of your day :)"
]
} | [] | [] | [
[],
[
"http://m.sciencefocus.com/qa/are-yellow-teeth-stronger"
],
[],
[]
] | ||
2ui23v | how does the brain produce voices and visions that arent actually there in cases of mental disorders like schizophrenia. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2ui23v/eli5_how_does_the_brain_produce_voices_and/ | {
"a_id": [
"co8l9t9",
"co8lrf7",
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"score": [
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"text": [
"One of the great questions of neuroscience. I would take a stab at doing an ELI5, but the short explanation for why I won't is that most of what anyone knows about auditory hallucinations is conjecture. You might crosspost this to /r/neuroscience and see if anyone there can help. \n\nWhat I **can** tell you is that it's a result of misfirings neurons in certain areas of the brain that deal with auditory processing. But as far as an easy and thorough explanation goes...I'll leave that to someone more capable. ",
"I remember reading somewhere that schizophrenic brains have activity patterns similar to people deep in REM sleep.\n\nIt would seem they are creating & perceiving their reality, just like a dreamer.",
"The speech areas of a human brain are normally all located in the left hemisphere (Broca's area and Wernicke's area). In a schizophrenic person experiencing an auditory hallucination, they have additional brain activity in the parts of the right hemisphere that correspond to the speech centers. In effect, the right brain is trying to \"talk.\"\n\nThere was a man named Julian Jaynes who had some rather peculiar ideas about cognition, consciousness, neuroscience, and the development of human society and religion. His ideas were... well, they had pretty astounding implications, but his reasoning looked sound and not crazy. One aspect of his theories is that he predicted this exact type of brain activity in schizophrenics, years before imaging technology existed to confirm it. His theories aren't regarded as gospel truth, but this confirmation did make significant and lasting changes on how schizophrenia is viewed and treated.\n\nOne of Jaynes' ideas was that the mind is not a single, monolithic entity. There's actually a bunch of components, and they coordinate to a greater or lesser degree, and the unity of identity is an illusion that the brain creates about itself, which is an aspect of consciousness. The part of the brain responsible for consciousness lives in the left hemisphere. Moreover, this part of the brain is not responsible for nearly as much thinking as you would like--thinking is handled elsewhere, and fed into the consciousness. In particular, the part of the brain that handles decision-making lives in the right hemisphere.\n\nJaynes' idea of a normal, functioning brain is that decisions are made in the right hemisphere, and then sent over as thoughts and integrated by the left hemisphere into the consciousness (or illusion of self). His idea of schizophrenia is that this process breaks down, and the consciousness treats these incoming thoughts and foreign intrusions rather than the normal way that things work. This can happen in a number of different ways.\n\nOne way things can go wrong is the right hemisphere uses its speech centers, and delivers words describing the thoughts in addition to the thoughts themselves. The result is that it *seems like* someone/something is commanding you to do certain things. Now, I want to emphasize: the vocalization is *in addition to* the normal information that the right hemisphere sends over, which is decisions. And the brain has no other source of decisions except the part which is now narrating itself. The consciousness receives the decision and acts on it, but also receives spech describing the decision. This is very hard for the consciousness to reconcile with itself, and in order to preserve the illusion of self it arrives at the solution that words and the decisions are arriving from an external source. The person now perceives their own thoughts as being alien to themselves, which has a lot of negative consequences."
]
} | [] | [] | [
[],
[],
[]
] | ||
1tqlu7 | do radio waves travel at the speed of sound or a different speed? | basically what the title says. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1tqlu7/eli5do_radio_waves_travel_at_the_speed_of_sound/ | {
"a_id": [
"ceah7t3"
],
"score": [
9
],
"text": [
"They travel at the speed of light, because they are a form of light."
]
} | [] | [] | [
[]
] | |
1mervv | why do we still need our licenses when we drive? | I don't understand why it is still required to have a license on your person when driving. With today's technology officers can just ask for your name and address and they can pull you up on their computer. The only real reason I can see for people to have their license on them is for age identification. Can someone explain why we still need to carry them? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1mervv/why_do_we_still_need_our_licenses_when_we_drive/ | {
"a_id": [
"cc8i8vk",
"cc8ja8b"
],
"score": [
2,
4
],
"text": [
"If you lied and said you were \"Joe Bloggs from 123 Example Street\", how would they prove otherwise?",
"In the UK you don't need it with you. When i was stopped by a policeman he just asked for details then sent me on my way."
]
} | [] | [] | [
[],
[]
] | |
2h89bj | if everyone agrees they hate the current cable companies, why doesn't a new company just come in and promise to treat it's customers well and take a large amount of business? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2h89bj/eli5_if_everyone_agrees_they_hate_the_current/ | {
"a_id": [
"ckq9gb7"
],
"score": [
3
],
"text": [
"Many industries, cable being a perfect example, have HUGE barriers to entry. Specifically in this case, actually physically installing thousands of miles of expensive fiber optic cable across the country. They would have to spend literally tens of billions of dollars to set up their business before they could even open their doors.\n\nThere just isn't really any way to get in to the market. That's why there aren't a ton of competitors.\n\nEven more so, in the event that they did try to open shop, they would have to compete with prices of the bigger companies, which would be very hard.\n"
]
} | [] | [] | [
[]
] | ||
dyl8hy | why do humans do wierd things when they are really horny? why did nature program us in such way, what's the point of that? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/dyl8hy/eli5_why_do_humans_do_wierd_things_when_they_are/ | {
"a_id": [
"f81pwua"
],
"score": [
2
],
"text": [
"Competition amongst males requires them to do crazy things in order to get female attention."
]
} | [] | [] | [
[]
] | ||
1o0pbn | why doesn't a slinky going down an up escalator keep going forever? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1o0pbn/eli5_why_doesnt_a_slinky_going_down_an_up/ | {
"a_id": [
"ccnsq46"
],
"score": [
4
],
"text": [
"Just as with a regular set of stairs, a slinky often will stop for reasons other than reaching the bottom. With an escalator, you would need to perfect the timing so that the slinky is not going too fast and reaches the bottom or too slow and hits the top.\n\n[Otherwise, it can work fairly well](_URL_0_)"
]
} | [] | [] | [
[
"http://www.youtube.com/watch?v=0L-P7XymVm0"
]
] | ||
3alyou | why does liquid pancake mix solidify when heated? | So when you make pancakes, you mix flour, milk, eggs and sugar together to get a liquid mix. When you make the actual pancakes though, this mix turns into a solid, which doesn't make sense to me.
I'm sure there's a good reason for this. Solids exists in lower temperature ranges than their liquid and gaseous counterparts, so why does pancake mix not follow this rule? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3alyou/eli5why_does_liquid_pancake_mix_solidify_when/ | {
"a_id": [
"csduh4t"
],
"score": [
2
],
"text": [
"Because a batter of pancakes is not the same substance as a pancake.\n\nAs the pancake batter is subjected to the intense heat it changes. new bonds break, gasses are released, protein chains break and form, molecules move closer together, and the batter becomes a pancake. The batter is liquid at room temp. The pancake is a solid at the same temp.\n\n"
]
} | [] | [] | [
[]
] | |
1pohgp | steroids reduce the effects of the immune system. wouldn't that make you sicker? | A lot of times when you get sick, the doc will give you a steroid shot to make you feel better. I get that you feel better because it decreases the symptoms. But, wouldn't you risk the infection getting much worse? Are there certain illnesses (flu, sinus infection, bacterial infections, etc) where a steroid injection would be contraindicated? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1pohgp/eli5_steroids_reduce_the_effects_of_the_immune/ | {
"a_id": [
"cd4cgn4",
"cd4cq6w"
],
"score": [
2,
3
],
"text": [
"Not if your immune system is the thing that's making you sick. Corticosteroids especially are used in autoimmune diseases like rheumatoid arthritis. I've never heard of them being used when there's an actual pathogen attacking your body.",
"If you have an active infection, steroids are definitely contraindicated. They are sometimes used to help with some of the lingering symptoms after a cold/upper respiratory infection (inflammation, stuffy sinuses, etc.), but only after the initial infection is clear."
]
} | [] | [] | [
[],
[]
] | |
36lpt8 | difference between vpn, pptp and proxy servers | Hi, as someone taking their GCSE ICT exam soon, I was unsure of the difference between these three as from my POV, they all serve the same function, thanks. Also, is Google Chrome's 'Incognito Mode' an example of one of these? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/36lpt8/eli5_difference_between_vpn_pptp_and_proxy_servers/ | {
"a_id": [
"crf1ktt"
],
"score": [
8
],
"text": [
"VPN is just a collective name for all Virtual Private Networks solutions that we have, of which PPTP is one.\nA VPN solution is a solution that encapsulates/encrypts all communication between your computer and a VPN host to get access to an internal network, such as your work network. \n\nPPTP (point to point tunneling protocol) is a Microsoft protocol for VPN access, it is a VPN/encryption protocol only so it relies on other protocols for authentication (such as PEAP) to establish connection to the VPN host. PPTP is not considered a very safe protocol so most today would use L2TP/IPSec or SSP instead. \n\nA proxy server is not an encrypted communication channel, it is just a way to route all your traffic via another host than your own computer. Proxies are used most commonly by average users to get a public IP adress that is different from your own. Since all your communication is routed via the proxy all requests from your computer will have the proxy's public IP address, a nifty way to get around geo locked resources for example.\n\nGoogle chromes incognito mode is just a mode where the browser doesn't save any of your browsing history, it is not a VPN and it is not a proxy, it's just a good way to hide what you browse for other users. "
]
} | [] | [] | [
[]
] |
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