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nvedmm | What does history mean when they say a figure was exiled? | Other | explainlikeimfive | {
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"It depends. Caesar was \"exiled\" during the Marius/Sulla shenanigans, but basically his name was put on a list(proscription list) where his property and inheritance was forfeit and he could be killed without consequence so Caesar was forced to go into hiding with family friends. If anyone not friendly saw him he was likely to be killed so he had to get out of Rome where people knew him, but the Roman Republic was a *big* place For Napoleon it happened twice. Once he was just dropped off on the island of Elba and told not to come back to France, it didn't work particularly well and he returned. The second time the British exiled him to St Helena which is inconveniently far from Africa, and they had two Royal Navy ships circling the island to make sure he *stayed* exiled this time Exiles are generally poorly defined and generally just \"Go away! If we see you again we'll arrest/kill you\" Details about individual's exiles are probably better for /r/history or /r/AskHistorians because there are only loose similarities between Caesar, Napoleon, and Castro"
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nveq94 | Why water in the arctic that's below freezing, not frozen? | I was watching a documentary about a team that was planning to go down to the lowest point on the ocean floor somewhere in the arctic. While the gentleman in the sub was going down, the narrator stated "at this depth, the water outside the submarine is below freezing". Soo... why is it not frozen? Does it have to do with the salt content in the water? ELI5, thanks! | Earth Science | explainlikeimfive | {
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"Salt lower the freezing point of water. In the same way that salt is used as an ice melter for sidewalks in winter.",
"Salt water freezes at a lower temperature then fresh water. This is for example why people use salt in the winter to thaw ice. But this also allows salt water to be cooled to a bit under freezing without actually forming ice.",
"Because its not below freezing, you're right that if it was below freezing then it should turn into ice Water in the deep ocean is very close to 4C always. Water is a bit weird in that it expands when it tries to freeze so water need the freezing point *floats* on water slightly above the freezing point rather than *sinking* like you would expect Water is densest at 4C so if the water gets any cooler than 4C it'll rise and mix with the warmer water. If its any warmer than 4C it'll also rise. The end result is that water at peak density sinks and displaces any water that isn't at peak density so any deep portion of the ocean is at just about the same temperature regardless of the temperature of the water at the surface"
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nvf337 | what is superposition of particles and how is it possible? | Physics | explainlikeimfive | {
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"\"Superposition\" is a word that means that the math that describes a particle adds together nicely. When I say \"add\" I mean literally the operation of addition, like 2+2=4. So what does that really mean, physically? Well, particles are, at least in some sense, waves. We describe them as functions [just like this]( URL_0 ). Okay, not exactly like that, there's also imaginary numbers involved, but don't stress on that as this is ELI5. In a sense, the wave function sort-of-kind-of is the particle, or at least the square of the wave function (called the probability density function) sort-of-kind-of is the particle. And this is where we get to superposition. When people talk about particle superposition, they mean that when 2 particles are occupying the same region of space, the wave functions add together, [just like this]( URL_1 ). That's all there is to it. If the height of the waves at a specific point are 2 and 5, they add up to 7 at that spot. How is it possible? It's a general property of basically everything unless there's a specific phenomena that physically causes the particles to separate. It's just like how if two ocean waves collide they can add together to make a bigger wave, or how noise cancelling headphones add the negative version of a sound wave to the ambient noise in a room so the total sound wave adds up to 0."
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nvgri5 | How do spiked shoes make runners faster? It's obviously counterintuitive but I would have thought extra grip would slow you down. | Physics | explainlikeimfive | {
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"Spiked shoes provide more traction for running on specific surfaces. The pressure from the foot pushing down and back could cause the shoe to slip over the ground instead of propelling the runner forward. The friction that helps maintain traction creates only a small amount of friction when the runner lifts their foot.",
"Friction is what allows you to push yourself forward without slipping. The more friction you have, the harder you can push.",
"I'm sorry, you're going to have to explain your thinking to me. How do you think that having extra grip, meaning more energy is transferred to locomotion rather than slipping on a surface, is counter intuitive? I'm not trying to be facetious, just curious to your thinking."
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nvh0mk | Condensation | Can you theoretically have an endless supply of water if you can find a way to collect the water that condensates on the outside of a water bottle? | Chemistry | explainlikeimfive | {
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"Not strictly speaking endless no. There's not an infinite amount of water in theair. However there is a process called fog condensation which actually uses the process that you described on a larger scale.",
"That water comes from the air. It deposits from the warmer air onto the cold bottle. It’s dew. Yes you could get an “endless” supply of water at a small scale. As long as you aren’t sucking entire clouds in, because then people might get angry. Rain is kind of good for the environment it turns out"
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nvi9gk | Why does water from a shower the same temperature as the room feel colder? | Physics | explainlikeimfive | {
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"So first; its important to note that what you can't actually feel \"temperature,\" but instead you feel rates of heat transfer. Now, heat transfer *is* partially dependent on the difference in temperature between you and the object you're touching, **but** its also dependent on the heat capacity and conductivity of the material in question. Water has a much higher heat capacity than air, and as a result water at room temperature fill soak up more heat from your body than the air, which your body will interpret as the water being \"colder.\" This is also why room-temperature metals feel cool to the touch.",
"Your skin is hotter than the ambient temperature so you're warming both the air and the water - but since the water is a better thermal conductor than air, there's a more rapid transfer of energy. By heating the water, you're cooling your skin - this is also why you sweat."
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nvicr9 | why can nerve signals only travel in one direction? | Biology | explainlikeimfive | {
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"They can travel along both directions within a single cell, but to jump between neurons a signal must traverse a gap by releasing some neurotransmitter, which initiates a signal in the next neuron. This can only happen in one direction, since only the axon can release and only the dendrites can receive."
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nvifq7 | In math, what exactly is a Manifold? | I’ve done way too much research trying to understand what it is but I can’t understand it. This actually doesn’t really need to be a full ELI5 but can someone explain to me what a manifold is without me having to understand differential geometry? | Mathematics | explainlikeimfive | {
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"A manifold is a space that \"looks like\" regular old Euclidean space (like a line, a plane, 3d space, and so on) if you zoom in enough. More formally, every point in a manifold has a neighborhood that is homeomorphic to (\"the same as\") a neighborhood in some Euclidean space. Easy examples include circles and spheres. A circle is curved in a global sense, but if you're realllllllly close to a circle, it looks like a line. Similarly, a sphere is curved in a global sense, but if you're really close, it looks like a plane (which is why the Earth looks flat when you live on it). If you cut off a little chunk of circle, it's essentially just a line (that is, it's the same as 1D Euclidean space). If you cut off a little chunk of sphere, it's essentially just a plane (that is, it's the same as 2D Euclidean space).",
"It's a very general term. A line is a one dimensional manifold. A plane is a two dimensional manifold. A field is a three dimensional manifold, and so on. A manifold can have any number of dimensions, and is called a n-manifold, where n is the number of dimensions. A manifold can go on forever, or it can loop back on itself, but it can't have holes and can't intersect with itself in any funky ways. So a figure-8 is not a manifold, because it intersects itself."
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nvim3d | Why are iron, cobalt, and nickel magnetic, but other metals are not? | Physics | explainlikeimfive | {
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"This is a really complex topic, but to start, electrons act basically as tiny little magnets. They have a North Pole and a South Pole, and put out a tiny magnetic field. In a lot of elements, electrons pair up, pointing in opposite directions, and mostly cancel out the magnetism, but some elements have unpaired electrons, which lets the magnetism add up, instead of cancelling. Even this isn’t enough though. Some atoms like to line up facing opposite directions, cancelling the magnetism. Only certain elements like lining up all in the same direction, creating an even stronger magnetic field. These atoms are called “ferromagnetic”, and that’s the type of magnetism you’re talking about. Because all their atoms like lining up in the same direction, and they have unpaired electrons, they can create a magnetic field, and respond strongly to outside magnetic fields. As for why certain metals like lining up one way vs the other, that’s some quantum stuff that’s way outside the scope of an ELI5. By the way, I skipped over a bunch, cause again, this is a really complex topic, but that should be enough to give you an idea.",
"The shape of the atom. They have a dangling electron which gives the thing polarity. If enough atoms are pointed the same way, the effects of those electrons sum up to macro-level effects like magnetism.",
"To Eli5, while this doesn’t cover all of it, metals form in crystalline structures, and there are a few different types. Some types arrange the electrons so that they are magnetic and others don’t (they are all magnetic, just to greatly different degrees). Also, most metals and metal alloys can be forced into different crystal structures by cooling slowly or rapidly. Take steel for example. Based on its heating and cooling method, and its atomic mixture, it can form various crystal structures. This site has a good explanation and pictures. URL_0 .",
"To add on to everyone saying the atoms are pointing in the same direction, they're not really pointing, we just use arrows to indicate the direction of a magnetic field. In reality, magnetic fields are circular.",
"I just have to put a top level comment here to point out I hadn't realised that cobalt and nickel are magnetic metals and want to thank the OP for pointing that out to me.",
"To have a magnetic you need a magnetic field, to have a magnetic field you need charges to be in motion and a force. You can either cause this by a current following into an element or alloy or the element itself would have it's own particles in motion. You see elements want to be in a stable state outside of chaos and to have that stable you need to have the same number of protons which are a positive particle and electrons that is a negative particle in which case the protons are centered inside the electrons and the electrons are around the protons in shells the first shell will have 2 electrons while the rest will have up to 8 and 8 electrons on the shell basically makes it very stable like having a highway with proper exists and traffic control but when the number isn't 8 the electrons aren't stable so they want more electrons to be stable. The thing is iron, cobalt and nickel like other transition metals don't have a number of protons to accommodate that number of electrons to become stable so how do these guys stabilize? Instead of only using their valence electrons they also use the shell below it when that happens you have the electrons travel in motion and they have a velocity and they cause a centripetal force and what happens is you get a magnetic field that is perpendicular to this force and electron motion basically [like this picture]( URL_0 ). & #x200B; tl/dr: Those elements got an unstable outter shell which gets the bois from the lower shell to do their dirty work which pisses off the laws of nature but their screams go the wrong way. Kinda like outsourcing...."
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nvjgo6 | what prevents people from using the routing and account number at the bottom of the check to steal from the account or write fraudulent checks? | Other | explainlikeimfive | {
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"There’s usually nothing stopping it but there are lots of ways to get caught. Before a check clears, banks may do additional verification of names or other details on the check which is easier than ever with today’s technology. Before accepting a check, most businesses do ask for ID. If the name on the check is wrong, it won’t go through. If the name on the check is right, it won’t match the scammer’s ID. If they have a fake ID that’s another criminal charge if/when they get caught. And it’s in business’s own interest to check IDs because they are the ones who won’t get paid if the check is bad, it’s not like shady businesses will just let a little fraud happen, they are the victims of it. It‘s kind of like stealing a credit card or skimming numbers and using it to buy stuff. Nobody’s stopping you at first, but eventually you’ll be on camera using it somewhere, or there will be a record of goods being shipped to your address. And the merchant you paid is the one who ultimately doesn’t get their money when the transaction gets reversed, so they will happily hand any info they have over to police to track you down.",
"It will leave a paper trail. What they'll do is print their own checks with these numbers and send the pictures to a unknowing 'mule' who thinks they are getting some sort of job lucrative job, with instructions to mobile-deposit that check into their own account and send most of the proceeds out in the form of gift cards or cryptocurrency. The mule is left holding the bag when the fraud is discovered.",
"Nothing. I work retail and a best practice (stuff you should always do) I learned when checks were more common was to always put checks in the cash drawer where they can't be seen. That way a person with good memory couldn't memorize a check during the brief moment the drawer is open. As a side note, routing numbers aren't unique and are Bank specific. 125000024 is the routing number I found on the Bank of America website for Washington state just now. There. I'm halfway to stealing a check. For clarity, when I say nothing, I mean that anyone who is stealing account numbers know how to do it. What stops me is I know its wrong. What stops you could be the lack of knowledge. Nothing is stopping someone who already does it and they have learned the best way to use the check info to profit."
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nvjojy | Why does it seem like prolific serial killers are less common nowadays in the U.S.? | Other | explainlikeimfive | {
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"There’s cameras and phones literally everywhere. Not only is it (obviously) helpful to investigators, but people can be reported missing waaay faster. 30 years ago, not being able to get ahold of a person for a few days was totally normal. Now? Everyone has a phone in them all the time, so not getting a response for a while is more likely to be cause for concern",
"In short: Modern technology. There are no fewer crazy people now than there were in times past. But, given that those types tend to be fairly intelligent, they're more cautious and protective. Trust me, the nutters are still out there. And, given that, it's not entirely inconceivable that knowledge of how things work these days has resulted in people who are better at hiding their tracks. Statistically, serials killers could be *more* common these days...we just haven't heard about them."
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nvjtre | How can so many types of normally nonsocial animals form social bonds with humans? | Is this just projection? Does your pet snake actually like you? | Biology | explainlikeimfive | {
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"A lot of those animals aren't inherently antisocial, either. They're smart enough to recognize the general fact that you are a source of food and comfort. That's plenty incentive to be nice to you. And a lot of animals have a sense of territory. You could just be identified as part of their territory. Also we anthropomorphize their behavior. Meaning we interpret their behavior from the POV of a human. But the reasons for their behavior and what that behavior means may be totally different. So we may see what they do as \"social\" but the truth is it isn't. I like the shade of a tree, but my behavior doesn't mean I an socializing with the tree or see the tree as a social equal. Maybe I don't even understand that the shade comes from the tree. So you'd be surprised if I cut the tree down later, but that's because you expect me to have normal human reasoning and know the shade comes from the tree.",
"For the most part, it's tolerance rather than a social bond. These animals recognize that you're not a threat or competition and you provide food and shelter and as a result, they don't behave aggressively or scared around you. The difference between tolerance and actual affection is that it can end really quickly when you do something to overstep those bounds and the animal stops feeling like you're not a threat. For example, the reason we managed to co-habit with wolves so well is that we have very similar social and communication frameworks. Wolves understand cooperative, hierarchical social structures and they're very capable of reading our body language and learning commands. The difference between wolves and dogs is that dogs have been selectively bred to crave our approval while wolves are far more individualistic and really don't care about your approval. That's why wolves and wolfdogs are considerably more dangerous than dogs. You can get along with them for years but you can overstep their boundaries without even realising it and they'll snap at you. Or if you prefer a simpler example. My uncle was an expert in reptiles and often worked as an advisor to zoos. He worked with large animals like crocodiles, dangerous animals like venomous snakes. The only time he ever got hurt was working with monitor lizards. He'd cared for these lizards for years, they were perfectly docile around him most of the time. Until one day he made the mistake of bending over to pick something up while he was in between a lizard and a raw bucket of chicken. The lizards saw him as competition for the food, attacked and shredded my uncle's back to the tune of several hundred stitches.",
"Because we take caretaking roles with them, they see us as parents, or at least as providers of food, which overrides their antisocial tendencies."
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nvk27w | Critical Race Theory? | Other | explainlikeimfive | {
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"The basic concept of critical race theory is that our modern society is shaped by racism due to the lingering influence of racist people who helped form our society's views and laws and concepts long ago. It's about analyzing how racism impacts the modern day. Critics of it feel that this theory often can be used to just go \"Bad things happened because of white people\" and believe that it focuses too much on bad things in the past and assigning blame. Supporters of it feel that the only way to get past racism is to acknowledge it and be aware of it, and that ignoring racism won't make it go away.",
"In a nutshell, it's a sociological set of ideas detailing how when laws are created by and society shaped by one race in power, those laws and societal norms, consciously or subconsciously, are formed to benefit that race and when laws are written by racist people, again, consciously or subconsciously, those laws tends to be racist. CRT does not single out any particular race, it can apply just as much to White People in America as Han in China. It at no point says or even implies \"White people bad\". Anyone saying it does is spreading or has bought into propoganda. Examples range from the blatant Reagan administration admitting it made a war on marijuana to go after Black People more making the existing marijuana bans racist in themselves to immigration laws written to favor European immigrants over Central American ones.",
"They've deleted your post, but I think you'll still be able to see my response. Critical theory (generally) is a critique of particular social systems. It's a way of analyzing a particular system and deconstructing it. The basic methods are the same, it just depends on what lens you want to use in your analysis. You can have critical race theory, critical feminist theory, critical economic theory, etc. The gist of it is that any social structure is going to have particular rules in place. Frequently those rules may *appear* to be unbiased. However, critical theory takes the position that they will *always* have a \"disparate impact\". In other words, they will affect some groups beneficially and other groups negatively. Critical race theory analyzes these differences through the lens of race. For instance, suppose the government creates a tax credit that lowers your taxes if you buy a new house. That doesn't sound racist at all, does it? But what if white people are 70% of the population, but are 90% of new home buyers? Then the government is effectively giving an under the table tax discount to white people. Critical theory takes the position that disparate impacts like these are inevitable (often intentional, but sometimes even subconscious). As long as you've got one group of people in charge, they're *always* going to pass laws that benefit themselves. People who believe in it think that the only answer is major structural change -- tear down the old system and replace it. The problem with that is no matter what you replace it with, you've got the same issues. Critical theory says these \"rigged\" systems are inevitable. Whoever is in charge is going to do the same damn thing. There are legitimate criticisms that critical theory brings up. But there's also a lot of blaming other people for anything that goes wrong.",
"Critical race theory is a school of thought meant to emphasize the effects of race on one's social standing. While \"race\" as a notion is a social construction and not rooted in biology, it has had real, tangible effects on people of color in terms of economic resources, educational and professional opportunities, and experiences with the legal system."
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nvkjhr | why is there no such thing as brown light? | Physics | explainlikeimfive | {
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"Brown, like grey and other colors not at full brightness, isn't just about what light enters your eye. It's about the *contrast* between what enters your eye and what the rest of your visual field look like. As an example, if you're outside during a sunny day, the 'black' asphalt on a street is actually reflecting more light into your eyes than the 'white' surface of an indoor wall does when you have the lights on at night. The reason the asphalt looks black is that it's reflecting much *less* light than the rest of the environment (including the lighter spots in its own surface), and the reason a wall looks white indoors is that it's reflecting much *more* light than its darker surroundings. To see a dramatic version of this effect, look out of a dark tunnel into a sunlit scene: almost everything looks brilliantly bright, almost white. Light can be orange, but brown is a darker shade of orange - which means it needs to be contrasted against something brighter in your visual field.",
"Brown can't be made with light because brown is a shade of orange. This means it's made with pigments. It's made by taking orange pigments and adding black pigments to it. There's no such thing as black light (I know UV lights are referred to as black light but they're not actually putting out black) so you can't make that shade of orange with lights and because lights aren't pigments you couldn't do it anyway. Edit: When you talk about primary colours there's different sets depending on if you're using pigments (and things like that) or light. Certain colours made with pigments cannot be made with light. Edit 2: You may be wondering why you can see brown on TV and computer screens. You can't, not really. It's tricks to trick your brain into thinking you're seeing brown when you're really not."
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nvkprf | Why are some items only ‘top rack dishwasher safe’? | What is the difference between the top and bottom rack? | Other | explainlikeimfive | {
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"The proximity to the giant heating element at the bottom of the dishwasher. When the dishwasher goes into its dry cycle, that heating element gets really really hot, the top rack doesn’t get nearly as hot as the bottom rack. Picture sitting right next a fire place versus across the room on the couch. Sure the fireplace warms the whole room, but sitting on the hearth is WAY hotter. So if you’re made out of plastic that could warp or deform from high heat, you should stay on the top rack.",
"Most dishwashers have a heating element under the bottom rack for heating the water and drying; top rack items can be damaged (melted/warped) by the extra heat.",
"Modern higher cost dishwashers place the heating element in the water pump and super-heat the water (which also sanitizes) during final rinse so that moisture will dissipate. Meltable dishes are safe top or bottom.",
"The heating element for drying is at the bottom of the dishwasher, and due to its proximity can melt plastics.",
"The top rack water has a slightly lower temperature - so some things (like plastic items) are less likely to melt/warp",
"A lot of plastics used in food containers are from the polyolefin family of polymers, polyethylene (HDPE) and polypropylene (PP), which get soft and begin to deform at 140F and 180F, respectively. The heating element in many dishwashers is at the bottom, so it’s more likely that deformation of those plastics will occur the closer they are to it. Most plastic containers are made from these plastics because they A) are food safe (aka generally unreactive to the compounds found in food and do not leech chemicals or break down when exposed to food) and B) are cheap as hell. For example the clear parts of Rubbermaid containers are usually HDPE and the lids are usually PP. Nalgene bottles are usually some specialized form of HDPE."
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nvl9e4 | What causes the blurry patches in someone's vision, or "sunblindness", when looking at a really bright light? | Biology | explainlikeimfive | {
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"Are you talking about the afterimage of the light you see in your vision when you look away? That's caused because the light-sensitive cells in your eyes use chemicals to detect the incoming light. In the normal course of events they have an excess of these chemicals and so your vision never fades or dims. However, if you look at something very bright, the chemicals get used too fast to be replaced, and so the cells don't work properly for a little while after you look away--until they can regenerate enough light-sensitive chemical to be fully functional."
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nvlr55 | What are prions? | What exactly are prions and what makes them so dangerous? | Biology | explainlikeimfive | {
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"Prions are misfolden proteins that not only do not do the job they are supposed to do, but can make other proteins misfold, enough misfold and the proteins can't do their job. The reason they're dangerous is because there is no real treatment for them",
"Prions are proteins that have been misfolded and that have, through some mechanism still unknown to biochemistry, can actually cause other proteins of the same type to misfold when they touch. There is no current effective treatment for them because any medication capable of destroying them would also destroy the patient, and prions often occur in tissues that are necessary preventing excision.",
"They're self replicating proteins. When they touch other proteins they turn them into other prions."
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nvly9l | Where did all matter come from? | I’ve hear before that the big bang wasn’t really an explosion, more of the point in time where the universe started rapidly expanding. Can someone explain where the all the matter that makes up planets, stars, etc. came from? | Physics | explainlikeimfive | {
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"Nope. It's still one of the great mysteries. We cannot yet discern any origin story for the universe that does not involve matter having to come from \"somewhere.\" There are theories everywhere from the universe being recursive to black holes being cosmic drains into other universes, sparking new big bangs, to getting into quantum mechanics. The truth is that we may never know, and that is ok. We're just three pound jellyfish in calcium jars. We don't have to have all the answers.",
"> Can someone explain where the all the matter that makes up planets, stars, etc. came from? No, they can't. There are different theories but what came before the big bang is entirely unmeasurable and therefore unknowable. Time, as we understand it, didn't exist.",
"The very early Universe was extremely hot, hotter than even the cores of the hottest supernovas today. It was filled with a soup of particles that, under the conditions we see today, would be incredibly unstable. As the Universe expanded, cooled, and aged, those particles decayed into other particles (in the same way that a radioactive element can decay today, but much more quickly). Eventually (and by \"eventually\" I mean \"roughly 1 second after the Big Bang\"), they decayed into the only particles that are stable for long periods of time (where \"long\" here means \"minutes\"): photons, protons, electrons (stable) and neutrons (unstable by themselves but relatively long lived) and the antimatter equivalents of each. For reasons that are not completely understood, more protons, electrons, and neutrons were made than antiprotons, antielectrons, and antineutrons: for every billion or so of each of them, there was one extra proton/electron/neutron. Each particle and antiparticle paired off and destroyed each other, which left just those few leftover protons, electrons, and neutrons. Over the next few minutes, some of the neutrons decayed, but most of them got stuck to protons. And finally, the Universe cooled down that electrons could attach to protons to form the first atoms. That left the following types of particles in the Universe: * A huge number of Photons (light) * A moderate number of Hydrogen atoms (electrons 'orbiting' [not really] protons) * A few Helium atoms (electrons 'orbiting' [not really] protons and neutrons stuck together) * A very small number of lithium atoms, which had even more protons and neutrons stuck together. The history of the Universe pauses here for a long time - many hundreds of thousands of years - in which pretty much nothing happens. But eventually stars formed, and the reactions within stars would convert hydrogen into the other elements we see today (in particular, all the elements other than Hydrogen that you see on a rocky planet like Earth)."
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nvmn2w | Why do some commercials play at an insanely higher volume than some other commercials? | Other | explainlikeimfive | {
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"Actually most of the video ads on tv have some restrictions but advertisers use some tricks. The Federal Communications Commission — the government agency that regulates the radio, television and cable industries — limits only the size of the biggest sound wave, the “peak level” of the sound. Under FCC rules, the peak of a commercial can be no higher than the programming it accompanies. The problem with this approach is that the peak level of the sound does not accurately reflect how loud something sounds to the listener. Our brains judge loudness by averaging all of the waves that roll by — big and small. One way they do this is to use a trick called “dynamic range compression,” which amplifies the softest sounds. This decreases the difference in size between the biggest and smallest waves. Compressed sound bombards the ear with more energy over a given period of time, audio that sounds flatter but louder."
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nvmr6i | why the cost of wood is rising so much? | Economics | explainlikeimfive | {
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"First of all, COVID shut down a lot of supply lines for everything. Second, the price of fuel is rising. Third, the housing market is booming, and there’s a lot of new home/apartment/condo building going on, which means there is a huge demand for lumber right now, and the principles of supply and demand dictate that the higher the demand, the higher the price will go.",
"I live in Canada BC where one of our major industries is logging so I’ll put it like this, the lumber companies thought that that the need for wood would go way down due to COVID instead construction didn’t really stop and a lot of people are doing DUI at home. Which has had the effect of lowering supply and increasing demand which led to the increase in price of that makes sense"
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nvmstf | How do hives appear so quickly after you eat something you’re allergic to? | Today I accidentally ingested something that I’m mildly allergic to, and within minutes I had hives on my shoulders and scalp (which is my usual reaction). I understand that hives are caused by your immune system being activated. What I don’t understand is: if you’ve just ingested the food you’re allergic to, how is it that your immune system gets activated before you’ve had any time to digest it? And why do hives appear on the scalp, which is far away from where the food would be absorbed? | Biology | explainlikeimfive | {
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"Digestion starts in your mouth! As you chew, saliva gets mixed in, which has white blood cells in it among other things. Those are able to transmit an immune response very quickly",
"People with allergies have heightened immune response to these allergens that can be activated with the smallest of triggers... be it smell, taste or touch... That is why asthmatics have instantaneous reactions to dust or wierd smells... Same happens to allergic food that is ingested... Also this immune reaction occurs in the blood, and so all the effects pertaining to this reaction can occur wherever the blood flows! Be it scalp, lungs, hands, legs.",
"Hives are caused by whatever you ate binding to an antibody that hangs out in your blood that activates a special kind of immune cell, called a “mast cell.” When the mast cell is activated, it triggers a bunch of other immune cells to activate and releases chemicals like histamine that make your blood vessels leaky, allowing immune cells and fluid to get from vessels into the peripheral tissues, like the skin of your scalp, causing hives and swelling. This all happens super fast."
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nvn82v | How can one companies 5G be “better” than another? Doesn’t 5G refer to the speed/strength of the connection? | Technology | explainlikeimfive | {
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"It all has to do with \"coverage.\" 5G is a *standard*, agreed upon by industry. The only difference has to do with how close you are to a 5G-capable cell tower (signal strength), which determines just how much you'll be able to do. Anything anyone says apart from that is...marketing drivel.",
"5G is a minimum standard. Specifically, it's the fifth generation of standards for cell networks (hence 5G). It's not so much a specified speed as it is an agreed-upon set of technologies and protocols that allow different networks and devices to work together. These technologies and protocols are more advanced than the previous generation, and as such networks built to that standard will deliver better speeds than networks built to 4G standards. Put another way, we're moving from horse-drawn carriages to automobiles. Some automobiles will be faster than others, or more reliable, or more luxurious, but they're all cars in the end. As long as you've got brakes, headlights, taillights, rearview mirrors, windshield wipers, and so on, you can register your car, slap on a license plate, and drive your car on public roads. 5G networks are the same way. As long as they're built to that standard, they're considered 5G. Yes, 5G marketing to the end user mostly just emphasizes connection speed, but coverage is also a big factor in what makes a network \"better\". Both also vary wildly according to the frequency used by the cell tower you're connected to: higher frequencies mean higher connection speeds, but higher frequencies also have a shorter range and are more easily blocked by trees, walls, windows, etc. Some networks are built out faster than others or prefer higher or lower frequencies. All these factors mean that the quality of a 5G network can be highly variable; even the quality of the *same* network can vary highly by location.",
"You may confuse the G in 5G to be short for Gb/s or GHz as these terms are used in other technologies. But in cell phone terms the G stands for generation. 5G is a collection of different protocols and standards set to replace the 4th generation ones. The actual speed you get depends on a lot of factors such as the distance to the cell tower and the spare capacity of that tower.",
"5G refers to the technology they use- these are the 5th generation cell technologies. It's an important component of speed, but speed can also depend on a ton of other stuff, like the radio frequencies they use, how close you are to a cell, and how many other people are on a cell. For example, Verizon has spent a lot of time setting up high-frequency 5G. Using higher frequencies makes it much faster than using the same technology at lower frequencies, but the tradeoff is that it doesn't travel as far so they need way more towers to get good coverage. As a result, Verizon only has 5G coverage in and around cities. T-Mobile, on the other hand, has been focused on the lower frequency 5G. As a result, even though your phone is doing the same thing once it connects to the radio tower, T-Mobile has much broader 5G coverage while Verizon's got a faster connection if you manage to connect.",
"One factor is that 5G uses different frequencies of light (referred to as spectrum). The cell towers are a lot like a lighthouse where it's shining a really bright (but invisible to your eye) light. Different frequencies of light interact with physical objects in different ways. To some frequencies of light, a brick wall is like a glass wall and will just pass through it. Others will go right through you like a glass version of you. Glass would be opaque to some of them. Some can really only go through the open air, the moment anything solid gets in between it stops the signal (the light from the tower). In the US, spectrum is managed by basically selling it to different carriers. AT & T owns a range of frequencies part of the 5G standard. Verizon owns a different range. T-Mobile a different set. They generally interact with physical objects the same way but there will be differences. Some frequencies are better than others. This means that for places like cities the companies have to pay special attention to how their spectrum for 5G interacts with buildings and humans to correctly position their cell towers.",
"While 5G is suppose to be faster then 4G, the advantage 5G has is access to higher frequencies. Think of frequencies as highways. The lower the frequency the less lanes it has, but what isn't used to make the other lanes is used to make the highway longer. The cars on the highway is the data being sent to your phone. A 1 lane road 100 miles long (low frequency) can't support as many cars at once, so it takes longer for 100 cars to travel on it. As the frequency increases more lanes are added, increases how many cars can travel at once, but it also makes the road shorter. So while 100 cars can travel quicker, then can no longer travel as fast. 5G adds support for really high frequencies that cell phones never really used before. Think of it like a 100 lane highway. Now those 100 cars can go at the same time, but the road is now only one mile. The trip is done way quicker, but now you gotta be real close. Low band 5G will be faster then the 4G LTE already using those frequencies eventually (short answer on eventually, not enough lanes are being given to 5G to be noticeably faster in some cases), and high band 5G is unimaginably faster then anything your cell phone has ever done, but the frequency is so high, that if you can't physically see the cell tower you will not be able to take advantage of the speed."
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nvnbre | How and what are you “seeing” when you visualize something with your mind’s eye? | How is it registered by the brain as seeing when it is so different than actual seeing with your eyes? | Biology | explainlikeimfive | {
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"It's not like looking at a photo and I don't have to close my eyes. I do have to actively think of what I want to see. So I have the thought in my head of, say, a blue sky over green glass with big, heaping white clouds and I will be able to, 'see,' that. It's like it's behind my eyes and also no where. Do you, 'hear, things as you think them or as you're reading? It's like that. Some nebulous place in your noggin that's real but also not.",
"The visual cortex doesn't do much interpretation, it mostly does pattern detection on the \"camera\" signals from the eyes... edge detection, color blob detection, range mapping... really low level stuff. It's the frontal cortex (and a bunch of other areas, namely the hippocampus) make sense of that information, assign it labels, and create the internal experience of interpretable vision. \"Your mind's eye\" more-or-less reverses this process.",
"Basicly its seeing without using your eyes. It uses the same area your brain uses to process information from your eyes, but instead of info from your eyes, it uses info from other parts of your brain and memory to form images. So imagine an apple. Your brain is using info you know and think about apples, it's using memories of what they look like, and it's using the visual center of your brain to put these things together and form an image without using your eyes. So let's imagine something that doesn't exist: a pink unicorn. Your brain takes information you know about unicorns: it knows its basicly a horse with a horn, and info it knows about the color pink, and puts them together. Even though you've never seen a horned horse before, your brain can put the image of a horn together with a horse and boom, unicorn. Now it adds the color pink and boom, pink unicorn. The less you know about something, the harder it is for your brain to make a picture. It's why you can't imagine an unknown color, because what would that look like? It's so fundamentally different you have no basis on which to create the thought. Furthermore, some people are better able to imagine things than others simply due to their brain being better wired for it. Some people are so extremely bad at imagination that they essentially can't. This is called aphantasia. These people don't have a \"minds eye\". It's not fully understood and it being a very subjective sense makes it difficult to study, but it's thought to be a spectrum in which some people are great at imagining, some people struggle, and some people can't at all.",
"Well, in actuality it's not that much different at all. We live in a simulation, a mental construct generated by our mind. It takes input from your senses to form this reality so we can navigate it, but it builds the entire concept and fills in the gaps all over the place. Your brain is incredibly good at this, and it doesn't actually need any outside stimuli to generate this mental construct. When you visualize something all you're doing is taking over some aspects of direct control and simulating what could happen",
"We don't know! Yes...It is a fact... How brain creates this subjective experience of recreating something objective is beyond science for now, except for a few speculations and theories. Because science cannot test the subjective. All we know is that there are centres in brain that help in visualizing, thought processing and recording memories, but we do not know how these work together to pan out to be a continous flow of imaginative thoughts called consiousness. So people around give their own interpretations like we are inside a simulation, or consiousness is something metaphysical or not belonging to the physical world, or like science, which simply accepts the lack of evidence to say anything about it for sure. So for subjective concepts with no sure explainations, its interpretations can also be subjective.... It is just like asking... Is apple the same \"Red\" for everyone?"
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nvnp3h | How does current creates a magnetic field | Physics | explainlikeimfive | {
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"It's a basic property of the universe. Every charge creates an electrical field. Every moving charge creates a magnetic field. If you involve einsteins relativity you can find out that both electrical and magnetic field are just different viewpoints on the same thing (If a charge moves or not depends on the observer) wich is why we called it the \"electromagnetic force\" wich is one of the 4 fundamental forces (and later got unified with the weak nuclear force too)",
"We don't really know 'how'. It is simply a fact that electrons are coupled to the electromagnetic field, generating an electric field by their presence and a magnetic field by their motion. We have no deeper physical principles, we simply call this coupling a \"charge\" and call it a day."
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nvods5 | Why do our eyes fill with tears when we yawn? | Biology | explainlikeimfive | {
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"Our eyes need to stay wet, so these glands produce tears all the time to slowly release onto our eyes. When we yawn, our face muscle contract and put pressure on the tear glands. This causes them to release excess tears."
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nvonm8 | What is Hololive, how does it work, and why is it so immensely popular that the "graduation" of one of the characters (?) is getting more attention than most things? | I looked around and it seems that it's a kind of VR (?) streaming thing where really people (or not) act as virtual characters? It's all quite fuzzy and inexact so hoping someone can help to explain how it works and how it came about a bit better. Thanks. | Other | explainlikeimfive | {
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"Think of it as streaming, except the streamer is playing a fictional OC and looks like one digitally. I personally disagree with the notion that anyone who watches them are either incels or virgin simps without a life, but that’s neither here nor there. It’s really just a niche, more specific form of streaming.",
"Hololive is a sort of talent company that deals in livestreamers (hope we don't need to explain that too) that use virtual avatars. They are called vtubers, they livestream on YouTube. As for why they are popular, I don't really know. I watch other Vtubers on other formats that aren't Hololive so I have an idea. But the range of fanatasism I see for hololive is vast. People watch them to see cute hyjinks while some young girl puppets a digital avatar. It's just obsessive idol culture at the end of the day, they are in fact virtual idols. Some like them in a reasonable healthy way, but some can be a little mental in the level of support they give. The use of \"graduation\" is a weird sinister term to me, all it means is that their contract with Hololive is up and they are stepping down. If the Vtuber in question is popular, it makes sense that there'd be a big crowd in attendance to see them off."
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nvp2db | How do conservationists that work with critically endangered species deal with inbreeding? | Say you have a handful of animals left from a species and you want to increase their numbers by basically getting them to screw in every which way but here’s the thing: wouldn’t all the next generation be related? After that the more babies they make the more inbred they’ll be. I feel like at the end, instead of saving the species, you would’ve created a new, different and really genetically poor species like pugs. Is that an issue they address? | Biology | explainlikeimfive | {
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"It’s tricky, but in the research I did, it all depends how many functional breeding pairs there are. If you have 2 males and 2 females, 1+1 got together, 2+2 go together and they should hopefully reproduce enough to create two new, non-inbred pairs. If there is 1 male, 1 female tbh inbreeding is necessary. Hopefully in the next few years (what with ‘cloning’) we should be able to create new animals literally out of thin air. Until then, imbreeding is unfortunately necessary.",
"It is indeed quite tricky and hard to avoid. They will try as well as they can to transport animals around between different zoos and reserves to take advantage of the full genetic diversity. But more importantly they examine the animals for genetic diseases and then try to breed the animals in such a way that these diseses goes extinct. The dangers of inbreeding is that these diseases will circulate freely among the limited populated and that recessive diseases will show itself more often. By carefully monitoring these it is possible to reduce this danger. This is kind of the opposite of what they are doing with dog breeding where genetic diseases are either ignored and diseased animals are just given life extending treatment so they can be bread and make lots of offspring or the genetic diseases are in some cases promoted. This is why pugs have such a hard time breathing as their malformed noses are favored over their natural short noses."
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nvptl3 | Can a lack of sleep be fatal? What physical harm can not sleeping cause the body and why? | Biology | explainlikeimfive | {
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"Yes, it can be fatal. There is a genetic disease where the person doesnt sleep and dies relatively young. Why? Unclear. Maybe constant cortisol from the strss. Maybe brain on hyperdrive. Regular insomnia isnt good in the long run but research sleep hygiene and youll find strategies to improve. Be patient. It is gradual. See sleep specialist if needed.",
"Yes. You will die of lack of sleep faster than you will die from starvation. You will start to hallucinate. And eventually you just shut down. There are many theories on why we need sleep but there’s no empirically accepted explanation why.",
"Yes but it doesn't typically occur in a normally healthy person - even if they are experiencing insomnia - because your body will engage in what is called microsleep where you sleep for incredibly brief periods of time - only a matter of seconds - and you may not even be aware that you're doing it. But it'll be sufficient to ensure that the vital sleep functions are carried out."
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nvpvsr | How do astrophysicists know what planets much further than we are currently able to reach or see in great detail tell us what they're made of or even measure their mass? | Other | explainlikeimfive | {
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"Elements like nitrogen or oxygen or neon show up as specific colors if you look at them through something called a SPECTROMETER. So for example if there's a lot of oxygen in a certain planet, and the scientists look at it through a spectrometer, it will look BLUE, and if there's a lot of nitrogen it will look RED, and if there's a lot of neon it will look PINK... so yeah... elements show up as colors thru a spectrometer. In terms of MASS... from my understanding there are some simple equations that are used. First they must calculate the distance. Once they have the distance they can figure out the mass based on the size."
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nvpzwl | why does White Torture work and not any other color, such as red or even black? | With every part of the methodology of white torture staying the same, would using any other color give same effect? | Other | explainlikeimfive | {
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"The aim of White Torture is complete sensory deprivation. A complete loss of identity and self. It works so effectively because white is seen by our eyes and minds as the emptiest colour. There’s nothing to see, or hide. Red is associated with passion and energy, black with mystery and deception. But white is just bland. Even grey is less bland. Ya ever hear the story of Amir Fakhravar? An Iranian student who spoke out against the regime, they subjected him to White Torture during his 5 years between different prisons. By the end, he couldn’t even remember the faces of his parents. Everything is white, even the clothes you wear and the food ya get served. The guards all wear padded shoes so ya can’t hear their footsteps. People have gotten PTSD from this method, it’s inhumane as fuck."
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nvq9ub | Do nuclear bombs and reactors give off the same radiation used in cancer treatment? | I was just wondering whether elderly survivors of tragedies like Chernobyl and Hiroshima would have lower chance of getting cancer | Other | explainlikeimfive | {
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"Yes and no. There are many types of radiation. Cancer treatments use x-rays, gamma rays, protons, or electrons. Nuclear bombs emit gamma rays and some x-rays but also other types of radiation that aren't used in radiation medicine, so there's some overlap, but it's not identical. And you have it backwards. Radiation exposure \\*increases\\* your risk of cancer, it doesn't decrease it. Large numbers of people exposed to radiation from the atomic bombings of Japan and from Chernobyl died from radiation induced cancer, and while radiation can treat cancer, it can cause an increased risk of developing a second cancer later.",
"In principle, yes. Gamma rays are gamma rays and those are the main \"type\" of radiation used in cancer treatment (although others like proton beam therapy exist). But they definitely **don't lower the chance of getting cancer**. Even radiation therapy itself increases the chance of getting cancer, but that's on the sideline if you already have cancer elsewhere. Any radiation causes damage to cells, and sometimes (read: extremely rarely) this damage leads to cancer. Using it against cancer is a gamble, you hope that you damage the cancerous cells enough so they die, without making more cancerous cells in the process."
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nvqaos | How does sunscreen let you get a tan but not get sunburnt? | Other | explainlikeimfive | {
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"Technically a tan is just a secondary effect of a burn. The sunscreen protects your skin from the suns radiation but not 100%. The sunscreen just blocks a certain amount of radiation allowing you to stay out under the sun for longer before more serious damage sets in. There is no such thing as a \"healthy tan\" URL_0",
"There are basically two main types of sun screen. Chemical sunscreen is absorbed into the skin, and absorbs the ultraviolet radiation, converting it to heat which is dissipated across the surface of your skin. I think most common spray/cream are of this type. Mineral based sunscreen forms a film over the skin, and reflects the ultraviolet radiation away from the skin entirely. Zinc is a common one, which is often used in sensitive areas like the nose and ears."
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nvqdya | I just noticed if I stand in front of two diagonal mirrors that meet, the vertical line between the mirrors will always be on whichever eye is closed. However, my friends noticed it goes to a single eye by default if both are open. How does it choose this? | Physics | explainlikeimfive | {
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"Surely you mean whichever eye is open? If you are looking with both eyes open then they will actually see different reflections, and which eye appears (in your brain) to be on the centreline will depend on which eye is dominant (at that moment).",
"it’s just natural eye preference. some people have it more noticeable while others not so much. it’s like being right footed or right handed vs left footed or left handed."
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nvr4qg | When you're hungover, why does it feel like noises and sounds are amplified? | Like how someone just talking to you can literally hurt your brain. | Biology | explainlikeimfive | {
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"Alcohol works as a depressant (at least in the quantities where you're getting a hangover), so once that effect wears off you probably have a period where you're getting to normal so the world gets louder again (not amplified but louder compared to what you were used to under the influence)."
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nvra7o | Quaternions | Quaternions are used everywhere from keeping satellites clusters in geostationary orbit, to just about every computer animated character. I hope this fits within ELI5: but I would love to hear someone's super simple explanation of 3D Quaternions, as they just make my brain feel like it's being levered out of my head, | Mathematics | explainlikeimfive | {
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"A quaternion has 3 imaginary parts and 1 real part. The imaginary parts form a 3D vector. If the real part is 0 then it is a pure quaternion- just a 3D vector. With a non-zero real part, the real part corresponds to a rotation around this vector-axis. Let’s say you want to rotate a vector (like the position of a point in space) around a known axis by a known amount. The position vector is made into a pure quaternion p. The rotation vector q is set up from the vector of the rotation axis in imaginary parts and the extent of the rotation in the real part. the rotated vector = q p q^(-1)",
"Quaternions are 4D actually, they are like an extension of complex numbers. Just like you can represent 2D rotations easily with complex numbers, quaternions pop out everywhere in navigation, or animation, because normed quaternions (quaternions of length 1) correspond to 3D rotations. To turn a vector: you just multiply it, left and right by a normed quaternion. (edit: missing an inverse here! multiply left by the quaternion, and right by its inverse, the maths to show this aren't necessarily pretty, but it's still a simple process that works!) They're better than using 3 angles (Euler angles like yaw, pitch, roll for planes, drones, etc...) because they don't suffer from \"gimbal lock\". For planes, when you start to fly vertically instead of horizontally, there are many sets of angles that describes your speed, so this causes lots of numerical problems. To kinda understand the problem: Turn your head to the sky, and ask yourself, which cardinal direction are my eyes pointed to? They're better than 3x3 rotation matrices because they're more compact, and you can interpolate them easily, which is harder with matrices. So in animation, you can define the orientation of a character's limbs with normed quaternions in a few positions, and you can get a smooth animation from this without too much trouble.",
"Disclaimer: not an expert on quarternions (or much of math!) The initial motivation for quarternions (by Hamilton) was driven by the methods and theories developed for 2D space. We can easily see that points on a plane (2D space) can be represented by 2 numbers as it is usually taught in school (the Cartesian plane is the usual introduction). Now the origin and direction for the basis of any cartesian coordinate system is arbitrary. But with a bit of math (nothing too complicated, multiplication and additions) it is simple to see how we can represent the basic movements of a point or line on a plane - translation and rotation. With just a bit more math, it is also relatively easy to \"stretch\" and \"squish\" lines on a 2D plane. All of this can be done using 2D vectors. The next challenge is how to change the basis of a plane - ie you can designate the coordinates from different \"origin points\" and different basis vectors (as long as they are not parallel). Basis vectors no longer need to be orthogonal (as in the simple Cartesian system) Once this is done, there is nearly a generalized system for representing points, lines and motions from any perspective on a 2D plane. So if there are 2 observers and they have 2 different ways of marking their coordinate systems, there is now a mathematical method to translate the representation of any 2D object from one observer's perspective to another. Also important, it is now simple to ask the question \"given an arbitrary vector in 2D space, how much does this vector \"project\" itself on a 1D line?\" This ability to determine projection is critical when changing basis vectors. Oddly enough, rather than using vectors (essentially a pair of real numbers), mathematicians found that using the complex number system gave them some even more convenient and powerful tools to handle the math of manipulation and representation. Using this idea, Hamilton wanted to extend these methods to 3D space. The initial idea was that since 2D space needed 2 numbers, perhaps 3D space only needed 3 numbers. This is sufficient for simple things like translation in 3D space but Hamilton struggled for many years because manipulations like rotations somehow did not work (simply) using only 3 numbers. According to the story, Hamilton thought of the idea of a 4 number representation (1 real scalar and 3 complex) while on a walk and scribbled it down on a bridge he was passing by at the time. This is the origin of the quarternion system. Essentially the quarternion does in 3D what the complex numbers do in 2D. This has widespread application in computer graphics because computer screens are 2D projections of a 3D object. Using quarternion math show how coordinates, movement and rotations for any 3D object can be translated to different 3D \"observers\" perspectives. Very importantly, how to calculate 2D projections based on different \"viewer angles\" is a natural part of that math. From one perspective, it is simple enough to say that all of these \"representations\" are, at its basis, just trigonometry and geometry using basic operations like multiplication and addition. As a whole, though, it makes things a whole lot simpler because the system is complete and generalized so it is no longer necessary to resort to breaking down every 3D problem into smaller 2D pieces."
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nvrfyp | why do you feel dizzy after spinning around? | Biology | explainlikeimfive | {
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"Becouse there's some fluid in your inner ear, which is responsible for the feeling of stability. If you spin for a longer time, the fluid starts to spin too, and it takes few moments to go back to normal, during that time you will be dizzy.",
"There are small containers filled with a certain fluid in the inside of your ear. The position and movement of said fluid gives your body a sense of balance - even if you, say, walk with your eyes closed. By spinning around, you apply centrifugal force to this fluid. In other words, it is pressed against the walls of its chamber. When you stop spinning, it takes a moment for the fluid to return into a resting position. As a result, your brain is confused because these fluids tell it your are still moving when you actually are not. This can go so far as to produce nausea, as our brains evolved to interpret conflicting signals from different sensory organs as being a result of intoxication - and the best option to stop it is to purge whatever is causing said intoxication from the body."
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nvrhi2 | Why do GPUs perform better than expected at higher resolutions? | I've always wondered about this but never found a satisfying answer that I could understand. To put some context and clarity into the question, 3840x2160 is 4 times the pixels as 1920x1080 which means one would expect a GPU's performance to be quarter of what it was at 1080P for example dropping from 120 FPS to only 30 FPS at 4K. But what actually happens is that the performance drops to 35-50% of the original performance at 1080P instead of the expected 25%, the same thing happens at 1440P, why does this happen? and why does it improve generation over generation? Also why do "bigger" GPUs from the same architecture scale better to higher resolutions than "smaller" or cheaper dies despite having similar core configurations and the same architecture? For example, the 3080 scales better than the 3070 and the 2080 scales better than the 2070, etc. Additional Note : The only odd exception to that rule is the 1080 which actually scales worse than the 1070 and was the worst scaling card in the spreadsheet I made, I wonder why it behaves that way. | Technology | explainlikeimfive | {
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"Not all the computations done on the GPU is done per pixel. A lot of the computations are done per vertex. Since the scene have the same number of vertixes no matter if it is rendered in HD or 4K this part of the computation is the same. So you would expect that the performance of the actual rendering dropps as the resulotion decreases but not linearly with the number of pixels. That being said you can often get away with lowering your graphics settings when rendering in lower resolution which will lower the number of vertixes in the scene as not all the details will be visible. And this will cause the performance to increase to something more similar to the expected result.",
"Not everything is harder at higher resolutions. Subject to all the myriad ways developers might go about implementing these effects, here are some things that might be barely or unaffected by render resolution: * GPU-based physics calculations, including how water looks * streaming world assets (buildings, trees, etc) in and out of video memory * shadow and reflection calculations, and anything else that usually has its resolution set independently by a separate game setting When increasing the resolution by 4x, all the things that are resolution-dependent get 4x harder, but this isn't everything. As for why beefier GPUs do better, I'm not sure, but I assume it's because the resolution-dependent features end up eating more of the pie when you have less overall. There's also to consider that lower end cards may run into memory limitations at high resolutions, since cutting back on expensive VRAM is a significant part of getting reasonably priced entry level cards profitable.",
"There is a lot that happens before the GPU even begins thinking about pixels. It is doing all sorts of triangle transforms and what not and the pixel count only matters at the Rasterization step, the very final stage of the graphics pipeline."
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nvruuf | Why does the iOS keyboard periodically forget common words? | Technology | explainlikeimfive | {
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"I think it's less that it forgets it, and more that it values it's own damn suggestions more than what you're actually typing. It's one of the things I like least about iOS currently. Like, the autocorrects for curse words is one thing, but when it assumes one word because it's more common, it's infuriating."
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nvskdu | How do Proof of Stake (PoS) block chains not create a broken system where the people at the top hold all the power? | I’m definitely missing something really simple but in my understanding the point of crypto is to decentralise and move towards a fairer financial system. Does PoS not just reverse this and put all the power back in the hands of a few? | Technology | explainlikeimfive | {
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"I mean, there’s not much difference between Proof of Work and Proof of Stake. Big players that can have more “stake” could already do more “work”. Decentralization doesn’t mean that big players can’t exert influence. A 50% attack was always a concern with Bitcoin and cryptocurrency overall.",
"I don't think that has ever been more than a sales pitch for crypto. And yep, as far as I know you are right. It does. But I suspect the difference is not really that great. Until blockchain can be sustainably utilized on a large scale without being an energy and resouce drain of monumental proportions it will keep being a hybrid between a ponzi sceme and a bubble.",
"The idea of PoS is the same as PoW. You invest money in the thing, and in return you get some back. The difference between the two is where you invest your money. In PoS you invest it digitally, in PoW you invest physically with computer parts / electricity bills, etc. In other words, PoS works off of the same idea as PoW, people with a lot of money can invest that money to make more money, and the fear of that investment being worthless keeps them from messing up the blockchain. To get even more ELI5: In Proof of Stake, you put up a \"stake\" in the form of coins. If you do something bad, you lose your stake, but while you have your stake up, you earn a percentage every now and then. In Proof of Work, you buy a bunch of PC parts, and try to do a whole bunch of math faster than anyone else. If you do something bad, then all the work you just did will be wasted, which wastes money. In both the incentive is there to keep person from doing bad thing, and in both the more money you put in, the more you get out."
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nvsz1u | How does our brain identify a music as sad, joyful, etc. ? | Other | explainlikeimfive | {
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"It's a cultural thing. The same music a westerner might interpret as sad, could be interpreted as joyful in another culture, etc.",
"Truth be said, we do not know... This is completely about a subjective experience...and thus cannot be researched upon... Although we can attempt to explain it by connecting them to our ability to process language... coz various melodies are infact language that we learn subconsciously... But, this theory does not explain how a baby knows that a \"lullaby\" is \"calm\"... Maybe he learns that too? We can never know for sure... Atleast not yet.",
"Similarities in how we express joy and sorrow. When we're happy, we're fast tempo and high pitch like a child's laughter during tag. When we're sad, we have a slow tempo with a deeper whine while mourning. It's not the music that's sad or happy, it's our interpretation in relation to how we react to those emotions."
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nvt0v1 | If muscles get stronger because we tear them when we work out, then why can't we medically cut them with a knife or something? | Biology | explainlikeimfive | {
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"When you workout you don't get a single tear in your muscle, you get thousands or tens of thousands of microscopic tears, in individual fibres, throughout the muscle. If you could somehow recreate these tears mechanically then you could just increase muscle strength without exercise, it's virtually impossible though. Also you'd still have the soreness afterwards as this is the tears repairing themselves.",
"It's the repairing part that strengthens them not the damage. That's why rest days are so important. The muscle fibres grow back thicker and stronger. It's also microtears not full on cuts through the fibres. That would be a torn muscle which is agonising and can put you on your ass for weeks and sometimes months. Definately does not strengthen you.",
"The process would have to be extremely precise, and be done on almost a cellular level, to mimic the exact effects of 'working out'. However, you are missing half the equation. One of the main parts of increasing strength is the neural changes that occur in your brain as your brain is learning how to use those muscle cells as you gain new ones. in fact, if a person starts weight training, they will find their strength making nice increases over the first few months and a large part of that is your brain being trained to use your muscles better. Basically, your brain learns how to better activate all the muscle cells as you are training. I guess in principle you idea could work, or alternatively maybe they inject some generic muscle cells into your body, but then your brain won't really know what to do with them. You'd have to go on an intense work out schedule to learn to use them. And if you don't use them, then they will atrophy back down to your 'before' muscles anyways."
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nvt210 | What’s the use of weather reports showing the “real” temperature instead of the “feels like” temperature? | For example, in the winter my city reaches 38 degrees, but often the “feels like” is 31. Why not report 31 as the main temperature? | Earth Science | explainlikeimfive | {
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"The real temperature is the temperature you get when you remove every other effect affecting the possible result. Variables could be, for example, residual heat, wind, evapotranspiration (evaporation + transpiration), sunlight, radiation, relative humidity etc. That's why there's a specific set of condition required to measure the temperature (you can Google it out easily). That's why your 'feeling' temperature is different than the real one (also your body produces heat and clothing). You, as a common folk will probably never use this information, however, certain business are heavily dependent on the correct information, it could range from characteristic of building materials, outside works on infrastructure (pipelines, railway etc.) and similar. It's also extremely important in agriculture - you need to have the exact temperature to set up other related practices correctly, from crops irrigation, the amount of water used etc. Edit: it's also important for future planning in many human sectors.",
"In that example the difference is actually very important since 31°F is below freezing so people would expect to see ice forming on streets and sidewalks, people tending gardens would need to account for frost, but since the temperature is actually 38°F that won't happen.",
"People don’t look at the weather report only to know what it will feel like to them! Even without going into more specialized reasons, I need to know so I can properly care for plants, for example. Some should be indoors or outdoors below/above certain temperatures. In short, animals and plants and objects don’t care too much about the “feels like” temperature cause it’s calibrated on humans. And humans need that objective information to guide a number of decisions and actions beyond what to wear :) Edit: I’d read this as if it was Celsius, but the other comment is very correct for freezing point. Same logic.",
"Because the \"feels like\" temperature is not the correct temperature but rather calucalted based on multiple factors and is subject to various other conditions. For example if you put on a jacket you are already changing how the \"feels like\" temperature would be calculated to fit your condition. A good wind jacket can be warmer then a thick padded jacket if most of the cold temperatures comes from the fact that it is windy. Similarly different areas get different amounts of wind and different amounts of sun. Plants and materials get cooled and heated depending on the actual temperature and not the \"feels like\" temperature. So it would be very deceiving to report the \"feels like\" temperature as the main temperature.",
"1. There will be ice on bridges at 31 F, not at 38 F but *\"feels like 31 F\"*. 2. A small farmer's bell pepper plants will survive 38 F fine with no cover, but at 31 F they will need cover. The weather is not only about whether you should wear the big coat or the hoody."
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nvta9v | How is the mobile phone signal different for each phone? | We always hear somebody say their phone has no signal. It's always confused me how some phones receive no signal yet there could be somebody right next to them with full connection and no signal interruption. I know the location, obstructions to cellular towers etc. are factors in limiting signal, but when both people are in the exact same spot what else is at play here? | Technology | explainlikeimfive | {
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"Two phones may be subscribed to different providers. One of the providers may have technical issues or just have a cell tower far away. Additionally, two phones may be from different manufacturers and have different sensitivity to low level signals."
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nvtwkl | how do they fit all the vitamins into a multivitamin? | how do multivitamins contain all those vitamins when they are so small? | Other | explainlikeimfive | {
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"The amount of each is very small. Think how light a gram is and realize most of the vitamins are maybe half that. Its like looking at a small bird and wondering how all those feathers are on it. The bulk of multivitamins are fillers, binders, and flavor",
"Your body only needs a very tiny amount of vitamins (which is why they are called *micro*nutrients). For example, a single orange contains about 70 milligrams of vitamin C - less than 1/14 of a gram. A multivitamin pill can contain lots of vitamin because it only has a very small amount of each vitamin."
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nvuol1 | Why does gas pain/flatulence hurt so badly? | I tried googling the reason for why trapped gas can sometimes hurt so intensely, but all it says is that a build of pressure causes pain. Why and how does the pressure of gas cause pain? How do we actually feel gas? | Biology | explainlikeimfive | {
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"The flatulence is inside your intestines. Your intestines are coated with nerves. These work to help move food along. When they are stretched, the contract back. This way when there's food in any part, it stretches the walls of the intestine, and the intestine pushes back and the food is moved forward. But with gas build up, the increased pressure pushes the walls and stretches them a lot. This causes too much stretch on the wall and the nerves in your intestine transmit that signal as pain. It also is made worse when your muscles try to squeeze back and the gas is, for any reason, unable to move forward. So that increases pressure, stretches the walls of intestines, nerves feel the stretch, and they tell your brain something is wrong at this part which is what pain is.",
"Pressure is pressure, whether it is caused by gas or anything else. As the pressure builds up, it pushes against the intestinal lining, stretching it out as far as your body allows. Ordinarily, it will escape out the path of least resistance (down the intestine and out your rectum) but sometimes the flow of air is blocked by the various twists and turns of the tract or by a large chunk of fecal matter, allowing pressure to build up to painful levels. When the blockage is finally released, the gas moves out explosively, which can sometimes cause pain in the sphincter muscle."
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nvv0f5 | How does "conserving" water, turning off my lights, ect, help? I know how it helps my bills but how does my tiny act of not leaving the water running actually help the "World"? | Earth Science | explainlikeimfive | {
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"Well... YOU individually? not much, admittedly. Your individual water and energy footprint is negligible in the grand scheme of things. But the reason why YOU are important is because if enough YOUs do things together.... doing things as US... THEN your impact becomes noticeable and significant. You laugh, but even a few hundred customers making conscious decisions can produce a trend noticeable to the data people at a public utility. \"Hey, I just noticed this whole neighborhood switched to water their gardens at night\" (yes, they can tell things like this). Just a few hundred customers writing into a fast food chain and suggesting switching to bamboo utensils or cardboard straws might be enough to trigger a change. Just a few dozen customers switching from plastic bags to paper at the grocery might be enough to tip the numbers such that it no longer makes sense to carry both paper and plastic, so they switch entirely to paper. Its seldom that any individual is in a position to change the World. But all you can do is act as though you can, and if enough of us do that, we will.",
"The more energy you use, the more energy the power companies need to make to supply the grid. That means more coal, oil, or natural gas that needs to be burned, or the more water that needs to be let through a dam, or the more a nuclear reactor needs to be run. For the first set of power supply methods, that means more carbon dioxide getting released into the air, causing global warming. The latter two aren't available to everyone and are limited resources (albeit harder to deplete). Potable, drinkable, clean water usually costs money to \"produce.\" The water you drink, unless it comes directly from a well, probably comes from the local water company. The water company cleans and treats the water so that it's safe(r) to drink. If you have your own well, you are taking water from the water table or aquifer below you. This water supply takes time to replenish, so high usage can deplete it over time, leaving you (and your neighbors) with less water.",
"It takes everyone saving 20% of their resources to save 20% of the total consumed amount. Without you we don't have everyone.",
"If you turn off your lights, then power stations need to make a tiny bit less pollution which damages the environment. If you are yanking purely about yourself, then yes the impact is tiny and almost insignificant. But if many people do it too, the energy saved will be much much larger, lots less pollution is produced and the world becomes a better place. Similarly with water, any you use and goes down your drains has to go off to a water plant to be treated before being sent out, the water plant uses electricity which makes pollution, so more people using less water, means the water plant needs to treat less water and overall makes less pollution",
"If you use more electricity, the power companies have to burn more gas and coal (which is polluting) to make more electricity. By using *less* electricity, you make it so that they can satisfy the needs of their customers while burning less of those polluting forms of energy. The same can be said of water. Actually only a very small amount of water on the planet is *fresh* water that we can drink, and in a lot of places it's not very easily accessible. When you use water, it winds up in sewage pipes and gets pumped out into the environment. First off, this can be dangerous to the environment - everything from medications to dish soap and shampoo finds its way out in rivers and lakes and the ocean and that can negatively affect wildlife populations. But also, it means that you have to use more power and more chemicals to treat that water to make it usable again for showering or drinking. Should also be noted that water conservation is also more than just taking shorter showers, watering your lawn less or using energy efficient appliances. Water is used to make a *lot* of food and clothing and all sorts of stuff that we buy every day. So changing what you eat and how often you go shopping for new clothes is just as meaningful for saving water.",
"if everyone did it, it would work my friend. Thats why the best thing u can do is be part of it",
"It doesn't, except in a very symbolic way. Industry and agriculture, airlines and shipping, use massively more energy (and pollute vastly more) than your household or your city or all the urban households in your country. But industry and agriculture don't give a damn, so they shame you into turning off your shower three minutes earlier to \"save the planet\". It's b.s. but makes everyone feel good: they can keep polluting and you \"saved the planet\". Want to pollute less? Fly less and never ever get on a cruise. A cruise ship emits the same amount of pollution per day as 3.5 MILLION CARS. URL_0 . So yeah, the idea that driving an hour less will \"save the planet\" is silly",
"It's important to stress what a few are saying here, the contribution to pollution of households pale in comparison to that of industry. Farming, manufacturing, aviation, shipping, all these things consume huge amounts of resources. The 16 largest container ships in the world produce the same amount of pollution as ALL THE CARS IN THE WORLD, some 1.42 billion cars. What's astounding, though, is that's actually an improvement. Larger container ships are more efficient than smaller ones, so building them bigger and moving more at once, retiring the smaller end of the fleet, actually reduces total planetary emissions. Global warming and pollution aren't a problem we can solve through individual responsibility - that mindset actually comes from a *very successful* propaganda campaign spearheaded by big industries who want cheap production and large profits. What we need is legislation and an international effort. Sustainable and environmentally friendly solutions aren't cheap, and industry can't do it on its own.",
"Do you understand the concept of adding and subtracting quantities? Might need a ELI2 here."
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nvv8de | What Is A Leveraged ETF And What Makes It More Risky? | Economics | explainlikeimfive | {
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"Through various means, they’re not investing in stocks directly but rather option spreads and other instruments that “leverage” the investment to return 2x or 3x the market return. If the market goes up, that’s fantastic. If it goes down, you get obliterated. If it goes sideways, you get eaten up by the cost of leveraging - options aren’t free. Since there’s a risk of absolute devastation when the market tanks and a slow-burn in flat markets, they’re considered extremely risky investments.",
"An ETF is an \"Exchange Traded Fund\". The details are kind of complicated, but the main idea is that buying a share of an ETF is kind of like buying a little piece of all the stocks tracked by the ETF. A regular ETF is a pretty safe investment, comparable to a mutual fund. Leveraging anything essentially means taking out debt or otherwise taking on risk to increase the possible returns. One way to think about it is that for every $1 you spend buying a leveraged ETF, you're also taking out a loan to buy another $1 of that ETF. If all goes well, your investment grows, you can pay off that loan, and you get to keep the returns from 2 shares rather than one. But if things to poorly, you stand to not just lose your initial investment but also leave the process with debt. So a leveraged ETF is risky, though still less risky than, say, taking out a lot of leverage to buy only one stock."
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nvvthb | what is the reason religious individuals tend to be more conservative compared to nonreligious? | Other | explainlikeimfive | {
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"Being conservative by definition is about upholding traditions and traditional value which is the basis of pretty much all religions. Also a trait of conservatives is a tendency to believe in maintaining more of a social order and following a structured law. Again a major component of religions. These are the main reasons religious folks tend to be more conservative. And I am not just talking about conservative in terms of the American political spectrum but conservative in general as far as human personal and behavioural traits."
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nvvxyy | How does lowering interest rates increase the value of asset of real estate? What are the factors that affect real estate prices? | Economics | explainlikeimfive | {
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"People take out mortgages based on what they're able to pay for their monthly payments. A $300,000 mortgage at 4% interest and a 25 year amortization period results in a payment of $1,578.07 per month. A $350,000 mortgage at 2% has a monthly payment of $1,482.08. You can see that even though the mortgage amount was higher, because the interest rate was lower, the monthly payment is lower. This means that, as interest rates go lower, people are able to afford bigger and bigger mortgages. Since people have access to more capital, the prices go up to match. Supply and demand.",
"Lowering the interest rate allows people to borrow more money. In a hot housing market this pushes the price upward because people can afford to pay more for a home they want."
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nvwl9a | how hard drives work. What in their design creates the “space” or capacity that each one has? | Technology | explainlikeimfive | {
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"A typical hard drive works by having a number of discrete magnetic switches on a spinning disk. These switches can be switched between 0 and 1 using a precise magnet - think about an old record player, where the vinyl disk is the hard drive disk, and the pin head is the magnet. It works like that. The head can move over each switch and determine its charge (reading it), or alter the charge of a specific switch (writing it). Charges are either positive, or negative, which we can assign as 1 and 0, thus allowing us to use binary encoding. To increase capacity, you need to increase the number of switches on the disk. You can do this by making a larger disk, or improving the technology so the switches are smaller. In modern systems, physical hard drives are getting replaced by solid state drives - this is because SSDs have less latency and quicker access time, can hold switches much more densely, and are more resistant to physical impacts since they don’t have moving parts. In an SSD, semiconductor cells are used in an integrated circuit to store data. These cells are organized into floating gates for flash memory - essentially, they are set so running the circuit provides information on which gates are open and which are not. Thus, for an SSD drive, like an HDD drive, the storage capacity is based on how small you can make those switches/gates, and how many you can fit on a certain area. Usually, this doubles every two years as it has since the 70’s."
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nvwnqw | How does stealth technology still work for aircraft? | Stealth tech was invented decades ago, and the premise is that it reduces a plane's radar signature to that of something very small - like a bird, or an insect. Ok. Fair enough. How come it still works? Wouldn't modern radars just be programmed to look for the hummingbird flying at 600 mph? | Technology | explainlikeimfive | {
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"The problem is sensitivity. How far away can a radar system detect a hummingbird? If it can't actually detect a hummingbird-sized object until pretty close (say 5 miles), then the stealth will have done its job. Modern air-to-air missiles and guided bombs can be launched from over 10 miles away from the target; so long as the stealth fighter can get close enough to launch, it has succeeded.",
"There is a constant battle between new radar tech and new stealth tech. The technology hasn't just been stagnant for 50 years.",
"The idea isn't to blend in with the birds. The idea is that you can't see hummingbirds from 100km, but maybe only from 3 or 4.",
"One of the problems is discrimination - ie trying to find the \"true\" signal from the background noise. You can always try to amplify a response to try to pick out something from a return signal but it ends up amplifying both the noise and the \"true\" signal. This is not a very simple problem to solve. Ultimately, there is a limit to the power emitted by a radar and a practical limit to how much amplification and filtering in the radio echo before it becomes swamped with noise. For example, if a radar tried to pick up objects the size of birds, then every bird flying will trigger a response leading to hundreds if not thousands of false signals.",
"Radar sweeps are FULL of clutter, false targets, ghosts, and noise. Once you have a small enough primary return you effectively blend into the background clutter and it's impossible to discriminate you from the other million little tiny random returns popping in and out. Radars try their best to filter out that sort of clutter, so you might just get caught in the filter and wiped away from the screen entirely. Radar operation is a lot more complicated and difficult than games portray."
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nvwri9 | Why does a winter storm lasts longer than a summer storm? | Earth Science | explainlikeimfive | {
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"You’re probably thinking of two different phenomena. The winter storms you’re thinking of are likely midlatitude cyclones with multiple stages whereas the summer storm you’rs thinking of is a simple thunderstorm. Conventional thunderstorms die in 1-2 hours, supercells have longer lifespans by a couple hours due to their anatomy and they normally form during the spring/summer. For the winter, conventional thunderstorms can happen but nothing other than confirmation bias would make them seem/be longer than others. If you’re thinking of a midlatitude cyclone, there’s a warn front that gets overrun by a cold front and become “occluded”, precipitation can happen in many different places and times when this is occuring. It may seem like one long storm but its lots of smaller snow/rain showers over a longer period of time."
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nvwyp5 | Air weighs 14 pounds per square inch, yet we don't feel it crushing us. The notion that internal pressure somehow acts as a counterbalance just seems to mean that we're being crushed in both directions. Shouldn't we feel this massive weight on us? | Physics | explainlikeimfive | {
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"If it helps, we're already \"crushed.\" Our species evolved on this planet; we evolved \"resistance to crushing of 14.7 psi_a\" as part of the process, because otherwise our ancestors would've died. With regard to the physics, most of our body is water, which is relatively incompressible, so that's not a hazard. What the barometric/atmosphere pressure *does* push on is the pockets of air in our lungs. Coincidentally, those pockets of air are *also* at about 14.7 psi_a (except we're actively breathing in/out), so the net force of the atmosphere on our lungs is basically zero. This means that there's no crushing at all; both sides being pushed the same means no net force to collapse our lungs. And our bodily structures, as mentioned above, evolved to survive that pressure, so they won't be damaged. Hence, we are crushed into a ball by outside pressure because we have internal pressure to resist it, and our individual cells/parts don't get crushed because they are individually strong enough to resist this pressure.",
"It's pressure, not weight. It's not a directed force, it's force on every surface. The air pushing in from above has the same force as the one pushing from below, same for left and right, etc. And yes, we *are* being constantly squished together by air pressure. That pressure is even necessary for life. Water is only liquid at room temperature because the pressure squishes it together, preventing it from boiling.",
"No, because it’s normal. When you feel pressure, it’s *abnormal* pressure, like someone sitting on your leg or something. If we evolved with more or less pressure, we would notice the difference on earth. Think of it like diving deep in a pool or lake; the deeper you go, the more it hurts because of the pressure. On the contrary, look at the blobfish. They’re so “blobby” because we see them in lower pressure environments than they’re used to. Their bodies can’t hold their shape because the pressure normally holds them together. As a result, they just sag everywhere.",
"You ever put a cup over your lips and started to suck out the air? You know that tingling, pulling, vacuum feeling? That's what it feels like when their isn't pressure there to \"crush\" you. Air pressure is like a nice comfy heavy blanket we keep wrapped around us at all times. Take it away and you are exposed, and it... sucks (air guns).",
"You *do* feel that pressure crushing you - you feel it 24/7, and you're accustomed to it, so you don't even notice it. Since all life on the planet (or on the surface, anyway) has evolved under that pressure, all life on the planet is adapted to live under that pressure.",
"One point I haven't seen yet is bouyancy. The 14 pounds of pressure on us isn't weighing us down, we're actually *slightly* lighter than we would be in a vacuum. Think about floating in water, the dense water pushes us up instead of crushing is down to the bottom. Air is also a fluid, but it's less dense than us so we sink to the bottom of this huge air ocean we're in. It still actually makes us lighter As far as not noticing it/feeling comfortable with it, our bodies feel a difference in relative pressure. We notice this in our ears during a pressure change (air travel, swimming) because trapped gasses push against our eardrums. However, once we \"clear\" our ears we no longer feel it until the pressure changes again. The rest of us, for the most part, is made up of water which is incompressible. If we're in a 50psi environment (scuba diving), our body is also around 50psi so we don't feel any pressure difference. There's no force pushing on our body to feel. Atmospheric pressure sensors are the same way, they're measuring the difference between vacuum and the pressure around it. If those sensors didn't contain a vacuum, they would be unable to measure or \"feel\" the pressure, you can only measure relative fluid pressure. Typical atmospheric air can only be consumed between 10-40 psi. However, if special air mixtures are used the body can actually handle a much wider range without any issues or discomfort, provided pressure is changed slowly enough. Space EVA suits are kept as low as 4.9 psi and the deepest scuba dive record is currently 1090 feet which is 472 psi of water pressure. Our bodies can handle even more than that. We can't survive at pressures where liquids don't stay liquid anymore and gasses don't stay gasses.",
"There are two things here to think about: 1) our insides are at the same pressure as our outsides (and are mostly incompressible for that matter). In other words we are at equilibrium with the air around us. 2) what makes us _feel_ the sensation of crushing is our bodies getting twisted around or deformed. This is also how we perceive something has been crushed....its physical form has changed. Because we are at equilibrium (point 1) we don't perceive any crushing (point 2). But why are we at equilibrium? Well it's important that pressure comes from all available directions. Imagine a water balloon. If you poke it with your finger, it would go inward where you poked it. If you put it between two flat plates and squished, it would compress outward through the gap between the plates. If you surrounded it completely except for one hole and squeezed, it would push outward through the hole. All that is deformation and it's \"crushing\"...if the balloon had nerves it would feel it, and you can see it happen. But if you surrounded the balloon completely with no gaps and pressed. It's made of water, so it wouldn't go inward really because water isn't very compressible. It'd remain the same shape. If it had nerves it wouldn't really feel it because there would be no change in the shape of the balloon to detect. The balloon doesn't have any gaps to be pushed into, so it doesn't change shape, so it doesn't get \"squished\"",
"Not sure about you, but I feel the consistent weight of unmet childhood expectations crushing me.",
"No, an entire cubic meter of air only weighs about 3 pounds (1.3kg) on earth’s surface. You are just feeling the pressure from all the air above you going up to space. That doesn’t push down, it pushes in all directions equally. So it squishes you.",
"14 lb of pressure is being applied to every square inch of your body from every direction 24/7. Your body evolved in that environment. If you were to add 14 lb to a square inch of your arm, you would feel it. But also, if you were to apply a complete vacuum to a square inch of your arm, you would feel a similar difference in pressure (though structurally different by anatomy). Thing is, there's no such thing as \"vacuum force\", and the most vacuum you can apply is 0, or 14 psi below normal. It's the lack of normal air pressure that feels weird, or damaging. One of the reasons being exposed to outer space is dangerous is because air in your system is supposed to be pushed in from all directions at 14 psi. Without it, that air expands... and kills you. Air is always trying to expand. Air is weighed down by gravity which keeps it on our planet. Air at the Earths surface is compressed by the 14 lb of air per square inch above it which gives us our standard, life-supporting pressure.",
"Air doesn't weigh 14 pounds per square inch. I've been reading comments and haven't once found that clarification. In fact, air weighs about 2,6 pounds per cubic meter. So that's quite a different number. What you are referring to is pressure. I.e. Force per area. The problem here is the god damn Imperial system using pounds as if it were a force, when it's really a mass. No wonder you guys get things confused. 14 pounds per square inch is equivalent to the pressure that you get when you stack 14 pounds of weights onto a surface as small as one square inch. Pressure is what you feel on your ear drums when you dive or even when you drive through a tunnel. I think a good way to visualize it is this: Imagine a pillar of air one inch wide from the ground reaching all the way up to the edge of the atmosphere. This pillar holds around 14 pounds of air. That's how much this pillar weighs. Now stack those next to one another until you fill in the entire surface of the globe. That's why the air pressure down here is 14psi. Why is the pressure also pressing sideways when gravity only pulls air down? Air - much like water - wants to flow and level out. The air at the button of the pillar is being squeezed out from underneath and wants to move sideways. That's where the sideways forces come from.",
"We are mostly liquid, including our nerve cells, with which we feel stuff. Liquid attains the same pressure as the gas in contact with it. If the pressure is the same everywhere - inside the nerve cells, outside them etc. - then there is no way for us to feel anything.",
"So one part of this question that the other answers don't really explain is where the weight from the air goes. Gravity pulls down the air, so surely you'd have a big column of heavy air. Right? What actually happens is that the gravity tries to squish down the air, but the air would rather spread out than squish, so it tries to go sideways, but sideways is more air also trying to squish down. So in a sense, the downwards force of gravity gets converted into an omnidirectional (every direction) force felt as pressure - instead of pushing in any direction, the air gets squished down at high pressure and pushes on every direction. This is what creates the pressure that other answers have discussed.",
"Your nerves are calibrated to be useful. Your body would not evolve to send useless signals constantly about the state of air pressure. That is a massive waste of resources. The same way if you make a scale to measure the weight of something you place on top of it, you would want to calibrate it to ignore its own weight. Otherwise you do not have a useful sensor.",
"We do feel it. It'd feel different if you found yourself in a vaccuum, don't you think? That being said, your body is mostly sensitive to changes in pressure. If the amount of pressure on you stays exactly the same for a long time you'll naturally stop noticing it. It becomes the \"default\" state and not worth any amount of your attention. This reminds me of people saying water has no taste. Are you sure about that? Is pouring water on your hand the same as pouring it on your tongue?",
"> Air weighs 14 pounds per square inch This is just a non-sense statement with no meaning. Work out the units. It is like saying \"gasoline costs $5 per degree Fahrenheit\". Not exactly \"incorrect\" but wildly off from the core idea you are trying to explore here. This all comes down to the physics concept of work and energy, but that is right on the edge of a one paragraph ELI5 treatment. Imagine placing a book on a tabletop. The book weighs one pound and has an area of one square foot. Gravity causes the book to push down on the table with one pound per square foot (force per area is known as pressure). The book is pushing down on the table, but nothing really happens. The table does not collapse, nor even move. From Newton's laws, since nothing is moving (accelerating) that means the whole system is in balance. We know the book is pushing down with 1 PSI, so that means the table is pushing upwards with 1PSI also to keep things balanced. Everything is steady and the table does not deed to \"work\" to keep the book up. Similarly, our meat-bag bodies have about 14 pounds per square inch always pushing down on us, because of the miles and miles of atmosphere above our heads. The atmosphere is the book and our face is the table... It is all in balance so nothing really happens, BUT, if you were to remove the external pressure by say exposing your body to the vacuum of space, that balance would no longer be in place and the internal pressure of your body would balloon outward without the confining force of the air pushing it back in. You would not be happy to find yourself in that situation."
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nvxa2y | why can't we just use some part of normal storage as RAM? | Technology | explainlikeimfive | {
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"We do. It's called swap space. It's a last resort because even an SSD is hundreds of times slower than RAM. A hard drive is a million times slower than RAM making the problem even worse. But honestly it's not needed as much in these days of fairly cheap gigabytes of RAM."
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nvxn8w | How is electricity physically measured (like at the meter on my house)? | Physics | explainlikeimfive | {
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"The old dial type meters are basically induction motors. They’re motors that spin at various speeds depending on how much current is passing through the meter. The more current (ie you’re drawing more power), the faster the motor spins. That motor is connected to the dials via calibrated gears that run the dial.",
"Maybe not ELI5, but here you go. Electricity is the flow of electrons. Electrons flow because they are pushed by a *voltage*. The voltage is like the pressure causes water to flow in a pipe. The amount of electrons that flow is termed the *current*. The current is like the flowrate of water in the pipe. More voltage (pressure) = more current (flow). So if you want to talk about flow, you might say there are 10 electrons travelling past a point every second (electrons per second), just like how you might talk about water flow in litres or gallons per second. If you want to find the total volume of water, you take the flow and multiply it by time. So if you had 10 litres per second, after 100 seconds you used 10×100=1000 litres. Same for electricity. You take the amperage, and multiply it by time. We could do electrons per second, but we use Amperes to measure current. We also use hours instead of seconds. So what do you get when you multiply Amperes and Hours? Ampere-hour (Ah), which is what you see on your electricity bill. The ampere-hour is the amount of electricity you used. Now we know how you measure time, but what about current? Inside your meter is a *current transformer*. This consists of a metal donut that surrounds the main conductor going into your house. A copper wire is coiled around the donut. The electricity going through the main conductor is AC (*alternating current*). Now when electricity flows, it creates a magnetic field. When that current *alternates*, so does the magnetic field. So you have an *alternating magnetic field* surrounding the main conductor. This fluctuating magnetic field causes magnetic field lines to pass through that copper coil in your little current transformer, and that *induces* a small current in the copper coil. This copper coil is connected to a smarter device which includes an ammeter which measures the current. This is then used to calculate the current in the main conductor. The current × time calculation is done at small intervals and added together to account for varying loads.",
"Electricity works by providing Voltage (the potential to do work) and flowing current (kinetic energy, literally electrons moving) thru your house's circuits. You are billed for how much electrical power you have used, and power is measured in Watts (Watts=Voltage times Current). It's very hard to measure power directly, but you can calculate power by measuring the instantaneous Voltage and current and then multiplying them together. In order to bill you, the power company needs to figure out how much power you used over time. The unit is Watt-hour (Wh, how many Watt's you used over the course of an hour). The meter will continuously calculate the instananious power, and then add that number to its sum (the sum is never reset). The power company reads that sum once a month, and you get billed for the difference between that number and last month's number. Older meters used a motor that spun some geared dials. That motor spins faster with higher voltage or more current (and the dial is calibrated in Wh). Once a month a meter reader (a human) would walk by your house and read the numbers. Modern meters use a computer to read Voltage and current and do the math. They report your numbers directly to the home office thru teh power lines."
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nvxxpn | what differences does lossless audio have on the sound of music, specifically on Apple music? | With the new release of lossless audio on Apple music, I'm wondering what noticeable differences there is to the music you're listening to. Is there a benefit/advantage to listening to the lossless version of a song vs the other? Edit: are there any noticeable effects for casual music listeners with basic audio equipment like Apple brand headphones and such? | Technology | explainlikeimfive | {
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"The media itself is only half the equation. If you have your phone plugged into a cassette adapter in the shitty 2-channel 10-watt tinny radio of an 80s Dodge truck, you will reap zero benefit. Imagine it like hooking up a 4K BluRay player to one of those old CRT TVs that came in a big wooden cabinet. Lossless audio is for audiophiles/enthusiasts who have invested in equipment for a fuller listening experience, whether it's high-end headphones or a full-on proper home stereo system or a car with a nice Harman Kardon stereo in it. That's the places where you'll see some difference with lossless audio. If you don't have high-end equipment or have an obsession with audio quality you'll probably do just fine with the non-lossless that takes up less storage and less bandwidth."
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nvy43a | How can camflouges in moths/insects imitate nature? Like, how does the camouflage of a leaf insect looks exactly like a leaf or dried leaf? Are they born with camouflages? If so, how does the genetics work? | Biology | explainlikeimfive | {
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"It's just that those who resembled those leaves the most had more chance of surviving. So they will reproduce and their offspring would look more like the leaves. From the offspring, those who resembled the leaves the most would survive, etc. After a while you get insects that almost look the same.",
"A moth was born with a random mutation that made them look a little bit more like a leaf. This made it more likely that they'd live, which made it more likely that they'd have time to reproduce, which made it more likely that they'd produce children with the same gene. Repeat for a thousand generations, and the descendants look a lot more like leaves."
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nvy8rm | How can tesla coils make sounds at specific notes? | To be more specific how does this person configure the tesla coils to make these specific note sounds. [ URL_1 ]( URL_0 ) Here is the link for the video. | Physics | explainlikeimfive | {
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"So the frequency at which the current moves in a Tesla coil is really high, in the tens of thousands of Hz. When a normal Tesla coil runs you hear this as a static buzz, but most of the frequencies are higher than we can hear. In order to make the Tesla coil produce a specific note you need to be able to modulate that high frequency. Basically, you need to turn it on and off really fast. If you modulate the high frequency at 500Hz (turn the coil on and off 1000 times per second) you hear a 500Hz tone. By programing a computer to control the modulation of the Tesla coil and follow something like a MIDI file, the Tesla coil can now sing a tune. Edit: [Here's an image]( URL_0 ) to better explain modulation. In this image, the Message Signal is the song we'd like to sing, and the Carrier Signal is the current moving inside the Tesla coil. By using the message signal to control the carrier signal, we get an output in the carrier signal that resembles the message signal. This image isn't exactly what's happening in the Tesla coil (this image is how AM radio works, the receiver recreates the message signal from that modulated carrier signal) The Tesla coil can only switch on or off so it produces a square wave, not a sine wave, but the concept is the same."
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nvydbx | How much 5G cell tower radiation dissipates within 3 feet of antenna? "Read description" | I understand that radiation from 5G towers are not of danger to the average person, but rather workers exposed for long periods of time and close to antennas. But 5G towers have labels warning of not entering within 3 feet of such an apparatus. My question then being, how much radiation from a 5G antenna dissipates within 3 feet? | Technology | explainlikeimfive | {
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"Others have answered the power question, but I’d to emphasize that these transmitters are **non-ionizing** radiation. The only thing they can do is heat you up. They can’t cause cancer or mutate your DNA or anything else scary you could think of.",
"The most import thing regarding the workers is the simple fact that they don't work on the tower when the tower is powered on.",
"Just to add it’s not just 5G towers, any microwave link has the same issue. In the old days when we used to work on public buildings roof areas we had to do a course as at one of our client sites you could effectively cook yourself if you weren’t smart."
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nvyvzv | /Does the brain have a limit for memory? Like smartphones, computers, etc | Biology | explainlikeimfive | {
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"Not really, but here is a good TED talk on memory: URL_0"
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nvyyfs | How do stocks work ? | If you had a lot of money, could you not buy a bunch of shares of a (usually stable) stock, which would cause the share price to rise (cause of a surge in demand caused by all the shares you just bought) and then sell your shares at the new price, making a bunch of profit. Rinse and repeat. | Economics | explainlikeimfive | {
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"As soon as your big sell order hits the market, people see that and the prices offered to buy will start to drop. If you split your order in multiple small orders then the execution of those will similarly make the price start to go down. You can't just buy or sell an arbitrary amount at the current price, only whichever volume is on offer at that price at the moment. So what doesn't happen is: Step 1) Buy 1 million shares at 10 USD. Step 2) Price goes up. Step 3) Sell 1 million shares at 12 USD. It's more like: Step 1) Try to buy 1 million shares at 10 USD. You get some at 10 USD some at 11USD some at 12 USD some at 13 USD some at 14 USD and some at 15 USD. Step 2) Try to sell at 15 USD? You get some at 15, some at 14, some at 13 etc. Net profit: Nothing.",
"You generally cannot do it that fast. As the other people here mention, things would be fine. But, what you are describing is a classic \"Pump and Dump\" scheme in the stock market. It is, technically, illegal.",
"If we think of an econ 101-level model of the situation, you likely wouldn't make money. If we assume that people's willingness to buy and sell the asset at various prices doesn't change just because you bought the asset, you would lose money from this scheme. That is, you would need to pay more and more to buy up the asset as you ran out of sellers willing to part with it for little. Likewise, as you try and sell, you'll quickly run out of buyers willing to pay the price you paid for the last few shares (after all, they likely would have already bought in at the market price before you started if they had such a high willingness to pay). The key to such a scheme is to change people's willingness to pay for the asset. In other words, you need to convince them that the spike in prices due to your buying is organic. Such an action, colloquially called a \"pump and dump,\" is illegal. Basically, knowingly making exaggerated claims to the value, such as trying to pass off a spike in prices from a large buy order you place yourself, of an asset that you own in order to get people to bid up its price, is outlawed."
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nvzjcz | How do countries exchange their currency to purchase foreign goods? Suppose India buys an Airbus plane from Germany, and India pays in Rupees, why would Germans accept Rupees if their currency is Euros? How does the Indian rupee get changed into Euros? | Economics | explainlikeimfive | {
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"That's the whole purpose of foreign exchange trading, why currencies fluctuate in value. Trillions of dollars in currency gets traded every day to facilitate international trade. India would need to convert Rupees into Euros to pay for the planes, and if the overall trend is more demand to convert Rupees into Euros then the Rupee would weaken against the Euro -- those willing to accept them would demand more for same number of Euros. But maybe Europeans are buying lots of textiles made in India that need to get paid for in Rupees, so the value of the airplanes and textiles evens out and the currencies stay relatively stable."
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nvzjjb | Why did thatched roofs not rot and collapse from the rain and damp? Or if they did rot, how frequently were they replaced? | Technology | explainlikeimfive | {
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"They did rot, but because of how they are layered on the roof, it sheds water pretty efficiently (that's how they didn't rot quickly, water shedding ability and tight layering protecting lower layers) and a well thatched roof in modern times can last 50 years before it's beyond use. Historically, at least in parts of England, a new layer of thatch was added to the aging/weathered layer and some houses have been found to have seven feet of thatch on them with the oldest layers being 500 years old.",
"Present tense, not past. Some of the thatched buildings in my village are 400+ years old and it’s not a particularly old village. Here most people get their thatch replaced every 25 years or so, but you can just get it spruced up a bit rather than replacing the whole lot at once.",
"The thatch was sometimes treated with linseed or flax oil. It dries to a waterproof hard coat. I was a roofer and my co-worker was from Poland told me this.",
"Thatched roofs use things like straw because they have an incredibly large C:N ratio. So the high carbon and low nitrogen make it slow decaying. Hence straw lasting so long"
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nw0emi | - How can you overdose on oxygen? | I read somewhere that it is in fact possible to overdose on oxygen. How is this possible & what would happen if one had too much oxygen intake. | Biology | explainlikeimfive | {
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"You overdose on oxygen by raising the concentration of it. For example the air we breath is about 21% O2, the rest is mostly nitrogen and other gases in small amounts. So if you raise the concentration to 100% O2 then the toxic effects become really high. That's why in hospitals, if a patient is put on 100% oxygen (sometimes they need to) the medical team will constantly reassess the patient and try to reduce that back to ~21%, if the patient can handle it. Oxygen is very oxidizing (it's where the word comes from) so it's very damaging to cells and proteins. The symptoms of O2 poisoning are: - seizures, dizziness, blurred vision, vomiting, confusion. Again, the only real way to suffer from O2 overdose is by breathing supplemental oxygen that is of a higher concentration than 21%. So oxygen tanks for divers/climbers, mechanical ventilation in hospitals etc. Some might even argue about the lifelong damages of breathing 21% oxygen but I don't think that fits into \"an overdose\" situation."
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nw0wwh | What does "Splenda (Sucralose) is 600 times sweeter than Sugar (Sucrose)" actually mean? | When I first heard about this, I thought, "Wow, I only have to use 1/600 of the amount of Splenda (Sucralose) to get the same sweetness as sugar!" So I put a sprinkle of Splenda into my unsweetened tea in fear that a whole packet would turn my asshole inside out, but it seemed like it had no affect on the sweetness of the tea. I see this everywhere because it's supposed to be one of the upsides of some artificial sweeteners, but I'm realizing that this definition of "sweetness" is very unintuitive. Does anyone know what Splenda is 600 times stronger at in comparison to sugar, or is this just a myth? | Chemistry | explainlikeimfive | {
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"Sucralose *is* perceptually 600 times sweeter than sucrose. Or rather the way it is tested, only 1/600th is required to reach the same detectable sweetness as sucrose. But, they don't put **pure** sucralose in Splenda packets because otherwise a single packet would be similar to putting 600 packets of sugar into someone's drink. That would be horrible! So instead they dilute it down until the packet will provide about as much sweetness as a packet of normal sugar. Of course this means there is very little sucralose actually in the packet.",
"For starters - yes Sucralose is 600 times stronger than sugar in the response it gives you. That is, that if you put 1gram of sucralose on your tongue it would be the functional equivalent of 600grams of sugar. Which is kind of a lot... BUT your packet of Splenda doesn't have that much sucralose in it. It's actually about 95% regular sugar (specifically dextrose which is just glucose), and only about 12mg of sucralose. So feel free to use the full packet, that's what it is designed for!"
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nw153e | why corn is so important and how it’s in everything. | Economics | explainlikeimfive | {
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"Corn is so important because it is one of the major grains that feed the majority of the world. Rice, Wheat, Corn, and other crops are the major food stuffs that are the backbone of the world. Corn also makes up a major amount of the feed used to feed livestock. Corn is “in everything” because cornstarch is a major ingredient in many things because it’s basically a cheap form of sugar.",
"Others answering here are wrong. The reason corn is so important and it’s in everything is due to a policy decision, not anything related to corn itself. The US subsidizes farmers for growing corn so corn has become quite profitable, leading to more people growing it. It has thus become a very cheap crop so processed cc FCC food companies has made efforts to put it in their products because it is so cheap to buy. They developed high fructose corn syrup as a great sugar substitute—due to the policy issues described above, it’s cheaper than sugar. It makes a great filler as well. Check out the movie King Corn for more details."
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nw24a6 | Mathematics and physics are linked together but is that possible to prove something mathematical with physical experiments? Conversely, can we prove by math something that we cannot experience? | Mathematics | explainlikeimfive | {
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"In terms of ELI5, the answer is no to both questions. Science (physics) and Mathematics have, at their basis, a very fundamental difference in what it considers \"knowledge\". Science, in general, operates by observation (empirical) and inductive reasoning. Science \"proof\" is evidence and credence based. In fact most scientist would probably avoid words like proof and truth in their scientific explanations. So it is usual to hear terms like \"most likely explanation\" or \"to the best available evidence\" or \"highly correlated to\". This is how science works - things are good enough until something better is found. Mathematics works by deduction and logic. Proofs in math are irrefutable and typically abstract given a set of axioms. This is a very different way of thinking of knowledge. Mathematicians are much more comfortable using terms like proof and truth relative to their work. In fact most of math is non tangible, it is abstracted to \"perfect shapes\", \"perfectly known measures\", \"perfectly random distributions\" etc. There are no such things in the physically observable universe.",
"Theorems of math can be disproven by counterexamples. If you can find a physical system as counterexample, you have just disproven the math theorem. Of course, disproving one theorem can prove another theorem. So physics can in principle help also prove some math theorem. I do wonder if this can help mitigate the Gödel undecidable theorems. E.g. there are some theorems that cannot be proven/disproven by math. But maybe by physical counterexamples.",
"Yes, you can prove that the volume of a unit sphere is less than a unit cube by making a box with a unit cube interior and putting a unit sphere inside it. Since this proposition is not close, the irregularities of the sphere and ball don't cause a problem. Conversely, almost all of string physics is only meaningful via mathematics. It's criticized for this, and if it turns out there can never be an experiment to validate the math, it will be seen as unfalsifiable, a kind of fake science like astrology.",
"Physics experiments can’t prove math: only illustrate its principles, like the sphere/cube example cited above. A more elegant way to think about it is that 1) math is just a subset of formal logic, which itself is a subset of epistemology, and 2) math is best seen in this context as the language that describes the principles. We can use words for example to describe the amount of force, friction, etc. but math is far more consistent and specific. So just like an idea can’t prove a word, an observation can’t prove the math, except insofar as the observation confirms that the math is an accurate descriptor."
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nw27dd | why does unusually high concentration of salt in water makes you float. Just like dead sea? | Physics | explainlikeimfive | {
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"The word of the day is *density.* Density is a property of matter obtained by dividing mass by volume -- that is, if an object with a mass of one gram occupies a volume of one cubic centimeter, its density is one gram per cubic centimeter. The more mass you have in a given volume, therefore -- the more stuff you have in a given space -- the denser it is. Salt water has more stuff in it than fresh water -- the salt takes up space between the water molecules. Dense objects sink, and less-dense objects float; so, if you have a body of water with *so much salt* in it that its density is greater than a human's, that human will float."
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nw3x9p | TIF Districts (Tax Increment Financing) | I am dumb, I have googled it and I just need someone to dumb it down for me. Sad thing is, I should know the answer for the profession I am in. I don't. | Economics | explainlikeimfive | {
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"With tax increment financing, you leverage the tax increment to finance public projects. The tax increment is the difference between the base property tax for a property, and the increase (increment) in taxes over time. So if you pay $1000 in taxes on your property in year 1 and $1050 in year 2, and your property is in a TIF district, that extra $50 in year 2 goes to service the debt for the project(s) funded by the district. This is just the simple structure of the deal, some of them are more complex, like the EIFDs in California.",
"Generally, property taxes are taken by a city or county (or whatever local government), put in a big pot, and gets spent on whatever the local laws allow property taxes to be spent on (normally schools and stuff). A tax increment financing district takes any increases in property vales in that district and puts those taxes in a separate pot to get spent on special stuff. It usually runs for a certain number of years. A few years ago in my hometown, a company wanted to build a new corporate HQ. They also wanted the city to fix up the surrounding area (repave the roads, new sidewalks, make the whole area nicer). So the city created a TIF district and agreed to use the increased property taxes to finance the improvements. The company took an empty parking lot and built a new skyscraper. They pay however much per year in property taxes. Whatever they used to pay when it was a parking lot goes into the general property tax fund. The rest of it goes into the TIF fund to pay for all the renovations in the area. That'll continue for the next 10 years or however long until the TIF expires."
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nw5p79 | why does alcohol make you so much more confident? | Biology | explainlikeimfive | {
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"Alcohol is a depressant, which basically means it lowers the activity in certain parts of your brain. One of those parts is responsible for social inhibition (or inhibition in general), meaning you become more likely to perform actions without you hearing the little alarm bell they would normally set off. To this end, it does not necessarily make one more confident, but rather reveals tendencies that were always there to begin with, but normally were kept in check by higher reasoning. This is why some people get mean and aggressive when drunk, while others are content to just sit there with a blissfully stupid grin.",
"Alcohol shuts up the part of your brain that says \"don't say that, that's stupid\", or \"don't talk to that girl, she's too pretty for you\". This makes you feel more confident, but it can also make you pretty obnoxious.",
"Among other things, it makes the part of your brain that causes anxiety and self-consciousness go to sleep."
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nw6vtg | Why is it that cicadas come every 17 years if they have a life span of 6-8 weeks? | Biology | explainlikeimfive | {
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"There are thousands of species of cicadas - the ones that appear every 17 years are just one species. And they actually live many years, just most of that time is spent underground growing and moulting and growing and moulting and growing *very very* slowly until they are ready to emerge.",
"Because they have a lifespan of 17 years, clearly. They simply spend around 16 years and 9 months of that time underground, and 3 months up in the trees screaming.",
"They have hatching dates in prime number years to avoid crossing over with other spawning years of many other animals. They seem to take ages to grow just because they burrow and therefore can’t get food very quickly."
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nw6yys | If good habits are rewarding and healthy, why is it easier to keep falling into bad habits? | I’ve been trying to sleep earlier lately because i genuinely feel great in the morning, and have a productive day. But I keep falling into the habit of staying up too late and feeling tired in the morning. This feels like a trend across the board. Why the self sabotage? Anyone got an explanation? | Other | explainlikeimfive | {
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"The example you're talking about is a type of procrastination; staying up late pays off \\*now\\* while the negative effects don't show up until later. Going to bed early \"hurts\" us \\*now\\* but doesn't pay off until later. We're wired up pretty strongly to prioritize near-term benefits over longer-term ones because of the heavy evolutionary survival pressure for a sure thing now against a more risky thing later. Successfully fighting this tendency is one of the major differences between children and adults, but it's always there. Good habits that pay off now area easy and don't backslide. It's the ones that you have to invest some \"pain\" for now in return for a (presumably) more worthwhile gain later that have problems. This is why exercising is so hard for so many people.",
"Bad habits tend to have instant gratification, wheras good habits only have delayed gratification. (Eating a pound of chocolate will make you happy right now, but going to the gym will only give you muscles and health benefits in the long run) This makes a lot easier for the brain to associate gratification with bad habits than it to good habits",
"Health psychologist here - to your question about good habits generally: any time there’s a ‘bad’ habit that’s tough to break, you’ve found something that’s inherently rewarding. Eating tasty food is an obvious one - taking in a lot of energy quickly has been a big advantage until very recently. Likewise, conserving energy and avoiding injury by minimizing movement was advantageous until very recently. Things that are both low-effort and rewarding are really likely to become something you feel pulled to do (like, habit). And things that are effortful and/or the reward is not immediately connected to the action are much less likely to become habits, and will always take some amount of effort and self-regulation. This is why it’s easy to mindlessly find yourself watching videos until the wee hours of the morning, but few of us will ever find we spent an extra hour running without realizing it!",
"I’ll explain it to you like your five, bad habit provides fun in the present, good habit provides fun in the future. When do you get fun the quickest? In the present.",
"Because \"bad habits\" generally have some reward that your body needs and only become a problem in excess, or in your mind, which doesn't have a lot to do with your physiology. Take food for example. Eating foods high in sodium or sugar is great for your body if you are in a resource lacking environment. That is where your body evolved. Humans have only had the level of overabundance of food we have for something like 70-100 years, so you are designed to want to eat had to get resources like sugar. Ignoring physical addictions like with heroin, most negative behaviors can be explained this way. For example, being healthy is important but most animals maintain their physique through their daily lives, not artificial exercise. In general, outside of obtaining food or sex, there is not a lot of advantage to wasting energy doing too much \"stuff,\" so being lazy is an evolutionary advantage. The more stuff you do, the more you have to work to get that energy back. So then why do you stay up late? Assuming you don't just have insomnia for some medical reason, if you are actively engaged in activity that is important to you, it's not easy to just cut that off and context switch. I don't know what you do before sleep, but if it's for example a high \"in dopamine\" activity like playing a video game, your brain is getting rewarded for staying awake, making it harder to take those rewards away and just sleep. tl;dr because most bad habits are overdoing something good or useful.",
"Habits are interesting. Habits are essentially just instructions rerun in your brain so you save time on things. The way they are formed is actually quite interesting. Bad habits arise when a positive feedback loop happens. For instance, the reason you may stay up late is because you want to do things you didn’t have time to do that day. This is an immediate reward, you put off bed time and do the things you enjoy, making you happy. This gets reinforced in your brain because it makes you happy. By the time you wake up tired, the effects of your choices are delayed enough and the habit is easy enough you’ll continue to do it. This is the positive feedback loop, it’s hard to break these, but entirely possible. There are 4 cycles in this loop: 1. Cue 2. Craving 3. Response 4. Reward For example, with your bad habit of stating up late, a cue could be you didn’t get to play a video game earlier in the day, so you want to stay up to play it. The craving is the act of plating the game itself, the response would be booting it up. The reward is actually playing it. If you want to break a habit, you simply have to break one of these cycles. The easiest I have found is the cue and reward. For instance, if I want to break the bad habit of drinking too much caffeine, I could either remove all caffeinated products from the house, minimizing cues. I could also replace them with decaf, removing the reward of caffeine. This works with visual cues as well, If I want to eat more fruit, I should put fruit out on the table in sight. I recommend the book atomic habits by James clear if you want more info."
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nw7hoa | if catching a cold is from bacteria, why do people say you catch a cold from being cold (e.g. going out in the snow without a jacket) | Biology | explainlikeimfive | {
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"It stems from an old wive’s tale, but in truth, when you’re cold your immune system is suppressed a little bit, so you’re _slightly_ more prone to catching a bug. Standing in an empty field in the cold and rain won’t give you anything but hypothermia if your core temp drops too low. No cold or flu, unless you come into contact with an infected person.",
"It's just an old wives tale that stuck around. A cold isn't caused by bacteria its caused by a virus.",
"thay are wrong. and it's a virus, not bacteria. a few years ago they found that low outside temperatures help rhinoviruses survive better near mouth and nose (don't have source), but a jacket or a hat will not help in any way against the cold or flu. the misconception comes fom the fact that viruses strive more in the winter, because people gather more indoors and in public transport/taxis so it helps spread the virus. URL_0",
"Because colds are more common in the winter, probably because everyone is inside with less ventilation than in the summer, so the disease has a higher chance to spread, it could also be that certain diseases are better suited for a cold environment.",
"It is usually a case of imprecise language. You don't get a cold just from being cold. You need to be exposed to a pathogen - virus or bacteria - as well. BUT being cold for prolonged periods of time may reduce the fitness of your immune system and can make you more prone to actually developing symptoms from exposure to a virus/bacterium. So while it is not the reason for the sickness, being exposed to cold weather can contribute to becoming sick.",
"Just a PSA: When you’re sufficiently cold, and you breathe in cold air, your veins and arteries shrink up. This is why you’re supposed to breathe through your nose so the mucous membranes can warm the air up a little bit before getting to your ventricle bits. Cold air + Physical activity can lead to heart attack. THE MOAR YOU KNOW",
"You catch a cold by: 1. Being exposed to a cold virus. 2. Your immune system not fighting it off. Cold dry air transmits viruses better, and stressing your body by being out in the cold without warm clothing makes your immune system less effective. Add these things together and going out improperly dressed in cold weather can *indirectly* cause a cold."
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nw7qaw | Why does the bank's interest rate effect the economy so much? Generally I only hear a small amount of percentage change, yet it's spoken of that it would have tremendous effect on the economy. | Economics | explainlikeimfive | {
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"The major effect is on how expensive it is to borrow money. Getting a loan when interest is high costs more, so less people borrow, so less economic activity powered by loans. Interest rates are typically small, so small changes are big \\*relative\\* changes. Going from 1% to 2% interest more than doubles the cost of the loan."
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nw8je6 | Why is it necessary to wear special glasses during a solar eclipse? And why can't you just use normal sunglasses? | I get why you can't look directly at the sun normally, for obvious reasons, but if the sun is blocked out, why is it still bad for the human eyes to look directly at it? What does the sun do to the moon that makes it bad to look at without protection? And why won't sunglasses do the trick, why do you have to use special glasses? | Physics | explainlikeimfive | {
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"Normal sunglasses won't adequately block out enough of the UV band of radiation that can permanently damage your retenas. Staring at a solar eclipse (or staring at the sun at any time) can cause a burned retina — called solar retinopathy or solar maculopathy — that can cause permanent vision loss. So having adequate eye protection when viewing a solar eclipse is extremely important. Certified \"eclipse glasses\" offer adequate protection from the sun's potentially damaging UV rays when viewing a solar eclipse. Look for documentation somewhere on the disposable glasses that says the eclipse shades are certified to meet the [ISO 12312-2]( URL_0 ) international standard for safe direct viewing of the sun.",
"If i remember correctly you dont need glasses at the exact moment of eclips... when a slice is visible though, same rules as regular sun apply"
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nw8ovi | How do You get the weight/mass of the sun without being able to weigh it? | Physics | explainlikeimfive | {
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"Mass and gravity are directly related. If you know one, you can figure out the other. We see how the sun's gravity acts on some object in the solar system (like the Earth) by looking at the characteristics of the Earth's orbit around the sun to figure out how strong the sun's gravity is. That gives us a ratio. Then all we need is to know the Earth's mass, which we do, and we can turn that ratio into an actual number.",
"You get some heavy objects with known mass, like big lead weights, and measure how much gravity they have, i.e., how much do they attract each other. We know how hard the sun pulls on us, because that's the force that causes the earth (and other planets) to orbit at given speeds and distances. So now we can work out the mass of the sun. [Cavendish did this experiment]( URL_0 ) in 1798 and got the answer right within about 1%. He used his results to calculate the mass of the earth but there were already reasonably good estimates of the ratio of the mass of the sun to the mass of the earth. The calculations assume Newton's law of gravitation is correct, i.e., that the force of gravity is proportional to mass and decreases with the square of distance."
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nw8x17 | - What are economies of scale? | Economics | explainlikeimfive | {
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"Let's say that I want to build a single car. I have to spend a lot of money to make a factory, to get deals for the metal, for the workers with the skill to make it, it'll be very expensive for me to make that one car. So if I'm going to sell that one car, it will cost a TON of money. But if I use that factory to make a 1000 cars, the money I spent on getting the supplies, building a factory, hiring workers, is now spread out over 1000 cars rather than just one. So I can charge a lot less for a single car now, because I expect to sell more. This applies to other goods and services. If I scale up and produce a lot more of something, it generally allows me to charge less for an individual item as a result, because the raw material to make the object is usually not the most expensive part of creating it. Hiring people and getting the facilities to make it is.",
"Economy of scale is just a term that means that it costs less to produce some item the more of that item you produce. Let's say you own a factory that makes 100 widgets a day. All the fixed costs associated with that (taxes on the factory, materials, utilities, salary...etc) means it costs you x amount to make each widget. If you scale up your business, (let's say to 1,0000 widgets a day) those costs go up , but you sell more widgets which means you get more profit at a rate higher than the cost went up, so it cost you a lot less to make each widget.",
"I’ll take a shot: Economies of scale basically means spreading a fixed or relatively fixed expense over a set number of products. Lets say you have one worker, Bob, and you pay him $500 every day to work. Bob’s job is to put together a jack in the box. If Bob only made 1 product all day you would have to sell jack in the box for $500 and a little extra to make money or profit. If Bob makes 25 products in one day you could lower each cost’s to $20 plus whatever margin. In reality there are a lot of other fixed costs allocated to each product, be it tangible or intangible. Lets pick on Tyson Foods. Tyson has a whole lot ‘back office staff’ that aren’t directly tied to making chicken products. In general the support staff required and other fixed costs (think buildings, utilities, etc.) won’t change too much depending on if a factory is making 1 chicken nugget per hour or if it’s making 50,000 chicken nuggets per hour. However, if the factory is making 50,000 chicken nuggets for hour the fixed costs are spread through each one. Overall and super simplicitc, it’s an equal with cost divided by product units. Whereby when product units increases, cost (mostly fixed) will decrease since the denominator is increasing.",
"I’d like to add that most of the answers address the idea of economies of scale but don’t get at diseconomies of scale Diseconomies of scale aren’t necessarily a bad thing but they occur when production hits a point where the size of the business has grown so much that costs per unit increase This per unit increase happens because you’re now you incur costs like communication or other operational factors or things beyond a businesses control To wrap it up I’ll just say Microsoft and Apple operate with diseconomies of scale but they’re still profitable companies but they spend a fair amount on communication and operations because of the sheer vastness of their companies and how the operate"
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nw93qx | Why do weeds grow so quickly and easily but growing plants from seeds is so difficult and take so much time? | Biology | explainlikeimfive | {
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"The weeds you see are the ones that are not only growing in their natural and native region and climate, but also the ones that are best suited for the conditions in your specific garden, that's why they grow so well. Many of the plants you grow for food aren't naturally found where you're growing them and also are bred for high productivity of their particular edible part not high survival against competitive plants in the particular environment you're growing them in.",
"You only notice the weeds, not the countless seeds for weeds that didn't take. if you really wanted to run an experiment you could get some dandelion seeds and try planting those like you do any other plant and compare how they grow vs \"desirable\" plants. My guess is that you'd get similar results.",
"Weeds are invasive plants. The reason that they grow so quickly and easily is because they're well adapted to the environment they're growing in, and have out-competed the natural plants of the area.",
"Firstly you have a seed bank. All soil has a seed bank, seeds that have accumulated from flora over the years. So many many seeds for these weeds are present. Secondly nature is smart. Most weeds are small plants, because of this they have to fight for sunlight. They sprout and grow quickly to beat out other plants so that they can complete their lifecycle, produce more seeds. Additionally some weeds spread via other methods but that’s not really important. A third thing to consider is what specific plants you mean when you say “growing plants from seeds is so difficult.” Is this plant native? Where is the seed sourced from? Native plants are of course much better adapted to the local ecosystem, soil types, temperature, elevation, humidity, and more effects plant growth. Seeds sourced locally, like those from weeds, have had a long lineage of surviving in the area. This means they are better adapted for survival as many generations have successfully produced offspring in or near the area.",
"Completely depends on the plant. It's not just weeds that grow fast. It's just because some plants grow so fast, they are invasive to our gardens and take over everything so we called them 'weeds'.",
"Some plants need more exact conditions to thrive than others. Specific soil composition, soil Ph values, moisture levels, the appropriate amount of sunlight and so on. Other plants need very little to thrive and will grow quickly and spread quickly. \"Weed\" isn't really a botanical classification, weeds are just plants that we don't want in any given location. When we cultivate the land, we know exactly what kinds of plants we want. And we don't want any unintended plants getting in the mix. We want our gardens to look pretty. We want our fields to be free of any toxic or unhealthy plants for our livestock and we want our agriculture to maximise the output of our crops. Weeds are just the plants that creep in and outcompete the stuff we plant. They take up the soil nutrients and water. They can outgrow our plants and block their access to sunlight. After all, we select the plants we want based on appearance or food yield, not because they're the toughest plants around. From an ecological perspective, weeds have their role. The plants we consider weeds are very tough. They can grow in very poor soil and very poor conditions. And they do. They grow, they die, their tissues decompose and add nutrients to the soil. As generations of weeds grow on poor soil, their lifecycle continually enriches the soil until the soil slowly becomes suitable for increasingly demanding plants. Plants that can't outcompete weeds on poor soil but will slowly replace weeds on richer soil. It's just a cycle that we don't want in our cultivated land. So we just weed out the weeds, artificially enrich the soil and plant what we want to have in the first place."
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nw9lc4 | Why does diving in a deep pool make the bridge of the nose hurt? | Biology | explainlikeimfive | {
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"Because all the water above you is pushing down on you. Since the bridge of your nose is a bit more sensitive, it may start to hurt. Some people also experience their ears etc. hurting."
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nw9q6v | Why do certain flavours and tastes stick in your mouth so much longer than any other? I. E garlic | Biology | explainlikeimfive | {
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"For garlic specifically, the flavor doesn't linger in your mouth per se; it lingers in your blood, where it gradually evaporates out through your lungs and your sweat. To quote the delightfully-named Wikipedia article on [garlic breath]( URL_0 ): > Various other sulfur compounds are also produced when allicin in garlic is broken down in the stomach and liver. Out of the many compounds, allyl methyl sulfide (AMS) does not break down quickly and remains in the body in significant amounts hours after consumption, resulting in an odor that can last for hours — or even for as long as two days. AMS is the only one of the garlic-derived organosulfur compounds detectable in the lungs or urine, as well as the mouth, which means that AMS is reabsorbed into the blood stream and travels to other organs for excretion - namely the lungs, kidneys and skin."
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nw9t0r | how does tooth decay happens ? | Biology | explainlikeimfive | {
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"Bacteria settles on food particles stuck on the teeth and as the bacteria digest the food they produce acid as a by-product and that acid slowly eats away at the teeth."
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nwaf9q | How do lasers “trap” atoms | Title says it. | Physics | explainlikeimfive | {
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"A laser is a stream of photons. The photons pass through the target and their path bends a bit when they do so. When they exit the target particle, they push the target back. When the target moves off-center, the stream of photons that kick it toward the center give it more of a push than photons that would kick it in any other direction. That's because a laser most intense towards the center. --- **More detail.** Photons carry momentum. Upon entering the target, usually a dieletric sphere or something small and relatively spherical like a cell, the light refracts. Since the photons have changed direction, their momentum vector changes. In order to conserve momentum globally, the target itself experiences momentum in the opposing direction to the change. This [diagram]( URL_3 ) uses ray optics to show two light rays 1 and 2 entering a spherical target. They refract inwards. Note how ray 2 refracts to the left, so the momentum it imparts to the target is to the right. In the righthand picture, target has moved off-center, but as a result the intensity along ray 2, which is now closer to the beam center, is much higher. That causes the net momentum imparted to the target to point right, back towards the center. This explains left and right trapping. For up and down trapping, you need to [focus the beam]( URL_2 ), which gives the laser a sort of \"waist.\" The rays now focus through that beam waist and a similar process of momentum transfer pushes the target back up or down towards the waist when it drifts away. **Fun fact:** Lasers don't just trap. They can *tweeze*. This was the heart of the 2018 Nobel Prize in Physics. By slowly moving the trapped particle, you can pick it up, translate it, and even rotate it. **Further resources:** - Cool [video of optical tweezers]( URL_0 ) moving around blood cells. - I haven't watched [this video]( URL_1 ), but Sixty Symbols usually does a great job explaining things. **Edit** Crap. You asked how lasers trap *atoms.* My response is more in line with trapping small particles and optical tweezing, not necessarily confining atoms. But a lot of the momentum transfer ideas still apply. Laser cooling, for instance, is when you slow down atoms by bombarding it with laser. In this case, the ray optics picture breaks down. Instead, the atoms absorb photons and then re-emit them in random directions. On average, this slows down the atoms."
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nwb9gi | why does arthritis cause deformities and angling of the joints | Explain it like I'm 5 What is the process that is happening in angling of joints? Why do joints seem to get bigger? Is there more deformities in osteoarthritis or rheumatoid arthritis? | Biology | explainlikeimfive | {
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"The word arthritis can be broken down onto 2 parts: the root word “Arthro” (meaning joint), and the suffix “-itis” (meaning inflammation). So the word arthritis literally mean joint inflammation. It is the inflammation itself (and sometimes altered movement and positioning to cope with or lessen the pain) that pushes the joints out of alignment and causes them to stay that way eventually. If I’m not mistaken, the irritation can also lead to scar tissue, which can cause further deformation. Of course there are different types of arthritis as well, but, I’m assuming you’re referring to osteoarthritis."
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nwbsuc | Why do animated films take some much computer power to create but don't need hardly any to play as a movie? | Technology | explainlikeimfive | {
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"Simple answer is that it takes a lot of computing to imitate lighting and effects, but the result is a single frame that is tiny as far as computers are concerned.",
"Do you mean 3D animated films for example? It’s because in film format, all that is being done is replaying video frame by frame in 2D, as with any other video. When making the things in the film though, you need to actually be able to render the things in it via a computer and modeling software, place it accordingly, animate it, etc. In short, everything is fully rendered in its raw format in 3D prior to being turned into a film. A film is just a series of 2D images/frames consisting of what the people making a movie want you to see. A similar comparison would be taking a photo of something in real life. Without taking a picture, you could walk behind someone and see the back of their head, what is behind them, things quite far away and so on. If you take a picture of someone though, the camera did not take a picture of the back of their head and what is directly behind them and such. You only see what the person who took the picture decided you could see. The rest is not in the photo. It’s not being “rendered.” This logic is also used when it comes to streaming video games in order to play them rather than having the game’s files and such on your computer and being rendered by your graphics card. A service will have the game running on THEIR hardware which responds to your input. The gameplay is recorded and provided you have very good internet, since all that is happening is that you are being streamed video from a game playing on another computer, you don’t need a good graphics card to play that game. Just good enough internet to watch a stream of it, because all you are “rendering” is 2D video at whatever resolution. If you download a movie, you are not downloading all of the assets that were created via modeling software and such in order to play it back.",
"To render a frame, you simulate light randomly bouncing around a scene. You start with the light source, cast rays in all directions, and a few of them end up in the camera after bouncing around the scene(technically you can start at the camera and go backwards, which I believe is how most of the ray tracing renderers actually work, but still most of the rays you cast don't end up at a light source): . The longer you let it render, the more realistically it mimics real light. At the \"camera\" you just count how many of those light packets end up in each pixel, and that's what you record and play back. Basically, the same reason it's much cheaper to play a movie from film than it is to re-create the set and have the actors play it out for every performance. You don't have to re-do the hard work because you recorded what the result was."
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nwbxrk | do speakers of languages other than English develop lisps? | Other | explainlikeimfive | {
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"Yes. Castilian Spanish is known for speakers using a lisp as a form of respect for a king who once spoke with one.",
"The word \"lisp\" is actually very very old, and dates to not just Old English (pre-1066 AD), but probably before known history, since there are words in the Germanic family of languages, like Swedish and German and Dutch, which are related to it in form and meaning. Words and sounds are changing in all languages, all the time. The idea of \"lisp\" itself depends on the viewpoint of a culture. This includes lots of changes to the \"s\" and \"z\"-ish sounds, including where they \"should not\" be. So: Yes!"
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nwd5lz | the difference between the rockets of today and the rockets during the Apollo era? | Also, what has changed to make landing a rocket back on Earth doable as to before? Could it have been done with 70's technology? | Technology | explainlikeimfive | {
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"Technically, the rockets themselves are not baaaaasically that much different, but it's now possible to put light, efficient computers on these rockets to perform the necessary control work. Back in the day it was not an option to put a huge, heavy, expensive computer on a rocket when it was simply cheaper to let them burn up and crash.",
"The big changes have been to the fight computers and the engines. The computers of today are far faster and much smaller, and have the added benefit of things like GPS for targeting landings. As for the engines, landing requires at least one engine to relight. Until fairly recently, first stage engines may or may not even be capable of lighting a second time. Even the Shuttle main engines, which were reusable, required extensive drying between firings. The Falcon 9 landing sequence requires the center Merlin engine to light 3-4 times in a matter of minutes, and be able to handle the heat of reentry as it does it. Starship is even more taxing, as the Raptors are also running what appears to be the most advanced gimbal program ever made.",
"I mean all the basic principles are the same, just some things are improved. It's kind of like the difference between a car from the 60's and a car made this year. Now we have lightweight composite materials, better computers for guidance systems, improved engines, some new welding techniques, and better computers for designing rockets and testing those designs, but a rocket is pretty much always a rocket. There's a reason the SLS looks pretty much like the Saturn V. The only major new thing since then is methane fueled engines, but even those engines still operate on the same principles and have the same parts. And sure, there's no reason why landing the 1st stage of a rocket from the 1960's couldn't be done, it would just have required a huge, heavy, expensive guidance computer and it wasn't worth the effort."
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nwe7uu | - How is it that there’s stories of people surviving losing limbs, wouldn’t that guarantee severe an artery? | Biology | explainlikeimfive | {
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"It might sever things but if you put enough pressure on the limb then it won’t bleed out as fast and help can get there in time",
"An unattended severed artery can kill in that amount of time. It's all about stopping the blood flow. Applying a tourniquet or worst case, cauterizing, will turn that hose into a dead end and help keep the blood inside you until you get real medical help."
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nwelbn | So I have read up on Half-Life of Isotopes, yet I’m still very confused on how and why the half-life is the reason for radioactivity and why it can kill us so fast and cause so much damage. | Physics | explainlikeimfive | {
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"The half life is the time that it takes for half of the material decay away. When the material decays it releases radiation. This radiation is in the form of different types of particles or photons. A shorter half life means that more radiation is released per unit time. A faster release of particles is more dangerous because more particles hitting you causes more damage. Edit: note that half life is not the only factor in danger. Different isotopes release different particles at different energies, and this also plays a large role in the danger of an isotope.",
"You're a little mixed up. The half life is not the reason for radioactivity, just a measure of how long it takes for a particular radioactive isotope to decay. If you're asking about radioactivity in general, that's a different question and there are plenty of excellent answers in this sub already."
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nwfr6j | Why does the other side of the pillow cool down more when you flip it? | Other | explainlikeimfive | {
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"Your body is hot 98F. Everything in the room is not hot 72F. When the pillow touches your head it becomes hot. When you flip the pillow it cools down to room temperature. Pillows don’t transfer heat well, meaning half can be hot and half can be cool"
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nwg4gq | why scientists say that no water could be found on other planets despite claiming that ice is present on certain places. Isn't ice and water are the same? | Chemistry | explainlikeimfive | {
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"> why scientists say that no water could be found on other planets They don’t. We have found water on many planets and other bodies within our own solar system (moons, asteroids, comets). It’s a lot more challenging to identify compounds which exist on planets outside of our solar system, but there are many such candidates which we think look like they may have water. Within our own solar system, water ice is pretty common in the bodies further away from the sun than us. Liquid water has been confirmed on Mars (not a lot of it at all, but it’s definitely there), beneath the water-ice crust of Saturn’s moon Enceladus, and is almost certainly beneath the water-ice crust of Jupiter’s moon Europa. Earth is the only place in the solar system we know to have large bodies of liquid water at the surface.",
"On earth, yes. But there are examples of “ice” on other planets that are other chemicals. For example, the ice on mars’ ice caps are mainly carbon dioxide. And I think Saturn’s moon Titan has frozen methane? But there are places in our solar system with large amounts of water and water-ice. Jupiter’s moon Europa and Saturn’s moon Enceladus are the biggest examples.",
"Generally when we talk about water in that context we're talking about liquid water. Yes, ice is frozen water, but calling ice water is not precise, and science requires precision. And also no scientist says that there can't be liquid water on other planets because we know for a fact that there is. We've detected trace amounts of transient liquid water on Mars, and Saturn's moon Enceledus is confirmed to have a vast liquid water ocean underneath its ice layer. Europa, a moon of Jupiter, is also suspected to have a subsurface ocean.",
"Liquid water needs very specific temperature and pressure conditions. For example, Mars doesn't have a thick enough atmosphere so the pressures are too low, and in the case of venus everything is way too hot. So on Mars we can have water ice, and water vapour, but they transition straight from one to the other (a process called sublimation). On Venus, it's all present as water vapour. It's possible that Titan has liquid water beneath its surface, but if it were exposed to the thin atmosphere it would immediately boil to vapour."
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nwglw2 | What does super straight mean I hear the word thrown around and couldn’t find a good answer | That or I’m bad at research | Other | explainlikeimfive | {
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"It was born out of retaliation for some sectors of the trans community who are not respecting people's sexual orientations, especially women's. Look up \"cotton ceiling\" as an example.",
"It's a silly term conjured up recently by transphobes to describe the idea of not wanting to sleep with transgender people. It's basically just virtue signaling, pretending to sincerely claim it's a unique sexual orientation when the initial intention was simply to troll progressive people pushing for trans rights. Here's another possibly better explanation: URL_0",
"\"SuperStraight is a sexuality preference where a cis person is only attracted and/or wants to date other cis people. So that would be someone who identifies and has all the biological make up of a gender they were born. Person 1: Would you date a trans woman? Person 2: No, though I respect their identity, I am SuperStraight, I prefer to date a woman who was born as a woman.\" [Source]( URL_0 )"
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nwhol3 | How are scenes where one actor does two or more different roles (In the same scene) filmed? | Other | explainlikeimfive | {
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"You can use a body double and angle the camera so you only see the face of one actor. Or you can use green screens, have the actor play both roles for the scene separately then stitch them together into a single scene via CGI. Or you use a combination of both. Have an actor and a body double act in one scene, then CGI the actor's face onto the body double."
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nwi1c2 | - How do Gas Giants like Jupiter have no surface? | As far as we're taught, the 'Gas Giants' Jupiter, Uranus and Saturn have no surface. So how do they exist? How did a bunch of gas somehow clump together and start orbiting our solar system collecting moons? I would have thought a large gathering of gas would simply dissipate if released into space.... | Physics | explainlikeimfive | {
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"Imagine earths atmosphere: wheren you fly from space, it's not like there is one place where air suddenly appears. It's a gradient of pressure. First it's couple pascals, then a little more, and suddenly, you are at sea level pressure. If there was no land, but gas underneath, the pressure would still increase, yet, the density still would be very low, so if you were to stand on jupiter, you would start falling, until all this gas crushed you. As far as \"existence\" and collecting moons\" are considered: it's one of the simplest rules of universe: masses attract each other. Gasses that Jupiter is made of, are very light, but not weightless. And there is so much more of them. Just look how big it is in comparison to earth. So that creates a gravity well, that keeps collecting more and more gas, and also, with time, created moons from space debris. Also, fun fact, Jupiter is a good guy, because his gravity field deflects asteroids in a way, that makes the change paths, and otherwise, earth would be so much fucked up. If anything is not clear, I serve with further explanation...",
"Because there was SO MUCH gas, its got a seriously formidable mass. There's just so much of it, that it actually attracts the other gas with gravity. So it built into the bigger and bigger ball of gas and the more gas that was pulled into one place, it pulled even more gas to the same place. Somewhere in the middle of Jupiter, there will be some solid and liquid, for two reasons, one - the pressure of all that gas will be forcing the gas in the middle into liquid form or even solid form. And because Jupiter is so MASSIVE, it actually sucks a lot of meteors and stuff into it, and they'll be found somewhere in the middle, knocking into the other solid bits in there. Jupiter is the vast vast majority just gas though, if you \"landed\" on it in a spacecraft or special suit, youd just fall and fall and fall, until the pressure around you crushed your space craft like an aluminium can under a tractor. Eventually you'd crash into something solid in the middle of Jupiter, but by that point you'd already be burned and crushed to the point that you were an unrecognisable lump.",
"Gas giants actually have a very dense, solid core. Although the planet’s core is small compared to its overall size, it’s still quite massive. (Jupiter’s core, for example, has a mass 16 times greater than Earth.) It’s also important to remember that gas is matter, just like a solid or liquid. The only difference between the two is energy (from heat). Hotter temperatures mean the molecules have more energy to move apart from each other. Any solid can turn into gas if it’s hot enough... That extra energy is not enough for the molecules to escape the gravity of a gas giant’s super dense core, however. That’s why the gas doesn’t just “float away.” You actually see this on solid, rocky planets too. Earth’s atmosphere is gaseous, and it stays around our planet because of Earth’s gravitational pull.",
"There are several theories of how gas giants form. One is the core accretion theory. Our sun is a 3rd generation star, borne out of a nebula of gas, and dust from the remains of dead stars that had gone supernova, and spread their guts throughout the galaxy. Atoms are matter, and where there is matter, there is mass, and there is gravity. This nebula eventually collapsed under its own gravity, beginning with individual atoms mutually tugging at each other. The inertia of the matter coalescing is preserved, and in short, the whole mass starts to spin. That spin, and the concentration of mass and gravity, causes most of that free floating matter to join in and average out - a spinning disk of dust is inevitable. And indeed, this initial spin and the plane of the accretion disk is still seen today, in the rotation of the sun and the orbit of the planets. So now we have a spinning disk of gas around a center that will eventually become our sun. The core accretion theory suggests the heavier atoms, those from the prior generation stars, formed a rocky core that began Jupiter. If you build up a rocky core large enough, you'll be able to hold onto your own atmosphere (I'm simplifying). Build a rocky core larger still, and if you're surrounded by an abundance of gas, your atmosphere will grow faster than your core. Eventually the planet reaches a critical mass, where the mass of the atmosphere itself is a significant contribution to the planet's gravity, which grows the planet larger still. Eventually the mass of the atmosphere becomes greater than the rocky core that started the whole thing. We're fairly certain these are the circumstances Jupiter was created, probably the other gas giants, too? But I didn't google the others. We've observed asteroid impacts on the gas giants, so we know they contain metals. The cores are insignificant to the mass of the planet, and we don't consider them to be a surface below a gigantic atmosphere. The core of Jupiter isn't massive enough to hold that much atmosphere alone. And there's so much gas and density increases so much that if you could survive a plunge into the planet, there's a point where you would just stop sinking because you reach equal buoyancy with the environment around you, thousands of miles above the surface of the core. The pressure is theorized to be so high that even hydrogen is compressed into a metal down there. This isn't the only way a gas giant can be formed. The early universe was filled with almost exclusively hydrogen and helium, and that gas coalesced into the first and second generation stars."
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nwi644 | How are synthesised voices (Alexa, Siri etc) made? | I’m assuming there needs to be a baseline with some voice actor, but with such a *huge* database of vocals and responses...how are ‘AI’ voices actually produced? | Technology | explainlikeimfive | {
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"There are several ways this is done. I worked in a commercial system in the early 2000s but not a whole lot has changed since then. Your idea is one of the more popular ways of producing natural sounding speech. A large amount of audio is recorded by a single speaker, and then chopped up into tiny bits and then put back together in different combinations. Older systems like this would use full phonemes (the basic sounds of speech) like the “s” sound combined with the “e” sound to make the word “see”. This was unnatural because there’s always some mismatch at the start and end of the sounds. By cutting the recordings into smaller pieces the speech can be made more natural sounding when it is put back together. This process of cutting up the recordings takes a lot of time although it can be sped up by using machine learning and speech recognition techniques with some human intervention. We needed about 6 hours of quality recordings including all possible sound combinations multiple times to make a new voice. Less than that would work but 6-12 hours would give the best results. There are other ways of producing speech that involve mathematical models of the human speech system. This is how some of the earliest computer speech was produced in the 70s and 80s, but it is less natural sounding (like the speech synthesizer that Stephen Hawking used) Finally more recently there are AI/machine learning generated voices that use neural networks or other “deep learning” techniques to generate the speech sounds. All of these techniques can be combined to make very good sounding voices these days. When I was doing work in this area some of the biggest challenges were around making the tone and cadence of the voices more human-like. We are still not all the way there but I am really impressed by the progress that has been made even in the past few years.",
"My mum has got ALS and as she’s losing her speech we recently digitised her voice so she can talk through that in the future. All she had to do was record 60 sentences with a budget microphone, send it off and a few days later they sent back her digital voice file and now when she typed anything it talks like her.",
"I saw an article some years ago who interviewed the woman who provided the voice for Siri, and she said that at the time she didn't even know it was going to be for an AI, and that they basically just had her make a lot of sort of \"nonsense\" noises that were pretty much broken down words/syllables. Because there was so much she did it for a while I'm pretty sure.",
"I worked at Google. Actually helped with Google assistant's voice (provided some voice clips for fun). What they do is hire a voice actress, and basically get them to read the dictionary several times with differnt inflections for each word. My meager addition was just an hour of reading random phrases so that the AI can help mix in non professional inflections into the mix so she doesn't sound so computerized. Ultimately that project was scrapped because the research shows that people like computerized voices. Anyway, now that you have a huge database with all words and different inflections, you feed a few billion hours of captioned audio to a machine learning algorithm, which processes each phrase and learns the right inflections on how to pronounce each word given its position and context in the sentence. Then, all you have to do is give this AI a sentence and it'll spit out the right inflectioned words 99% of the time. That's the majority of it, there are algorithms for constructing words that aren't in the database but the accuracy is something like 90-95% rather than 99.5% so they don't use that."
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nwjoqq | Why phone charger cables (white/light colored ones) turn yellow/brownish after some time? | Chemistry | explainlikeimfive | {
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"A lot of plastics and rubbers have bromine elements added to them making the plastic fire resistant. But when exposed to light, especially UV light, over longer periods of time there is a chemical reaction taking place turning these bromine elements yellow. The process is reversable. By oxidizing these elements the plastic will turn back to its original color. The most common way to do this is with hydrogen peroxide which is also used in a similar way to remove hair color turning the hair blond or white."
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nwjpn7 | How come sometimes your skin is itchy but when you try to scratch you can never hit the right spot? | Biology | explainlikeimfive | {
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"Our body's sense of localizing a stimuli is less accurate than we imagine... Try this for example. Close your eyes.. ask your friend to lightly prick you with a needle anywhere on the body.. try to reach that point with your eyes closed with one go... You are most likely to reach just 2-3cm near the exact point. So this is more likely to happen if you are scratching parts that are not visible to you, like your back."
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nwk98r | Why does is get particularly hot before it rains later that day | Earth Science | explainlikeimfive | {
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"When it’s hot there is a lot of evaporation from the surface - the soil, plants, bodies of water etc. Hot humid air from the surface then rises up because it has lower density then cold upper air. As this humid air rises it cools down, and water condenses back out, forming clouds. The higher it goes the more water gets condensed and the higher the chance of rain which takes all that water back down. And the higher the temperature of air initially the higher it can rise."
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nwkcqo | What's that feeling before eating something sour? | Have you ever been about to eat something sour, say a lemon, you feel this tingly feeling on the area below the tongue as if the body is anticipating the taste. Anyone have a way to describe this or the name of the effect if it has one? (didn't know which flag :/) | Other | explainlikeimfive | {
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"You feel your salivary glands working. Saliva has many uses and you are producing it day. If your body decides you need a lot of saliva right now - for example if you haven't eaten in hours and really crave that sandwich in your hand - you can feel your salivary glands squeezing out all the saliva they can muster. A lemon works especially well because another use for saliva is diluting damaging substances, like acidic lemon juice. So when you are about to bite into a lemon, you subconciously know your mouth will get flooded in citric acid, so you drench it in saliva first to lessen the damage done to teeth and tissues."
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nwkwy9 | How do heat-seeking missiles work? do they work exactly like in the movies? | Technology | explainlikeimfive | {
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"Early ones were really simplistic and just pointed the missile to the hottest thing it sensor could detect, be that a planes exhaust, the sun or flares (decoys). They had limited steering ability and only worked when shot at a plane from behind it (called \"rear-aspect\"), and even then weren't that reliable. Modern ones are much much more sophisticated. They have high-resolution infrared cameras, can detect and track planes from all angles, ignore flares, plot efficient intercept courses, are much more manouvrable and fully integrated into the planes targeting systems. A modern AIM-9X for example can be given targeting data from the planes radar or helmet mounted sight prior to launch and can track a target up to 90° to the sides (of boresight), allowing pilots to shoot at targets without having to point their own planes nose even close to it.",
"One thing usually gotten wrong in movies is that most missiles, including many if not all heatseekers, have a rocket engine that burns only for the first few seconds of flight. Hence, kinetic energy of the missile starts getting lower once the engine shuts off, and the missile is less maneuverable and therefore has a lower chance of hitting a maneuvering target at longer range. Therefore, maximum range and maximum effective range can be quite different. Some missiles do have sustainer rocket engines to maintain propulsion over a longer period of flight but I can't think of any heatseeker missiles with sustainerers.",
"When in doubt, assume the movies are portraying everything incorrectly. In this case, the big difference between the movies and real life is that missiles are wildly faster than planes. The classic visual of a pilot frantically dodging while a missile follows just on their tail is nonsense.",
"I still haven't seen an explanation of the \"heat-seeking\" logic of the problem that I really like so here's my attempt. Starting with the old IR (infrared) missiles it's fairly simple. If you take an IR camera and point it at the back of an engine it there will be a very obvious hot spot. ( URL_0 ). Because the difference in temperature between the engine/its exhaust and the environment is so large its easy to identify that as a targeting point. That is why the earliest missiles could only be fired from directly behind the target where they could see directly into the engine where the largest temperature difference would be. Then versions were made where they could detect the difference using just the exhaust instead of the engine core which greatly expanded the angles they were usable from, but still weren't effective if the exhaust was out of line of sight. Flares exploit the simplistic nature of this temperature difference logic by creating a larger temperature difference so the missile tracks them instead. To combat this engineers changed what the IR camera is looking at essentially. With better sensor technology the missiles no longer look at just what is the brightest thing in the field of view, instead they look for airframe heating. As a plane flys it encounters air resistance which is essentially friction between the plane and the air. That friction heats up the plane (this is part of why the fastes aircraft require special materials). The temperature difference between the friction heated aircraft and the rest of the sky is measurable but still fairly small. There can certainly be other things in the missiles field of view that have a larger temperature difference, so the missile has to know what it's looking for. To solve this these missiles have a form of image recognition built into their computers so that they can recognize aircraft shaped temperature differences and target those specifically. That makes it much harder for flares to fool these missiles while also allowing the guidance computers do a better job figuring out where the target is going so the missile can get there first. Others have covered this in other ways but \"Do they work exactly like in the movies?\" No. If a missile goes past a target will it turn around to try again? No, at that point it has been defeated. Will a missile chase for over a minute while right behind a plane very slowly getting closer? No, most missiles travel far faster than the aircraft they're targeting and aren't going to slow down to give you time to think. Can you out maneuver a missile? Yes... But it's very very rare and will usually leave you in a very vulnerable position to the next missile. There are methods to reliably defeat missiles, but that isn't one usually.",
"Historically they have been pretty simple, The first ones didn't track at all and just exploded when they got near something hotter than the empty sky, then the seeking ones were invented long before computers so they were just a rocket that had a ring of infrared sensors around the nose that would turn the rocket vaguely towards whatever was hottest. And they didn't really fly around chasing things as much as they would sort of vaguely auto correct a shot that went near a plane to a shot that hit the plane. Now that computers are a thing and missiles cost hundreds of thousands of dollars, they do act more like cartoon missiles where they can fly around chasing things all over. The line between missile and drone gets smaller by the day.",
"The missile knows where it is at all times. It knows this because it knows where it isn't. By subtracting where it is from where it isn't, or where it isn't from where it is (whichever is greater), it can obtain a difference or deviation. The guidance subsystem uses deviations to generate corrective commands to drive the missile from a position where it is in to a position where it wasn't. And, arriving at a position where it wasn't, it now is.",
"As Scott O’Grady pointed out, they are much, much faster than depicted in movies. Like no time to react at all fast and one nailed him brought the plane down.",
"The robot eyeball sees a hot thing and is all like \"ah that's hot\" and then gets the extreme desire to kill the thing",
"Video cameras are sensitive to infrared (heat radiation) as are with light. You point a camera forward, without infrared filter, and feed the video to a calculator. Any time the heat source is not in center, the calculator steer the missile until it is centered again. The result is the missile chases heat. The tech behind better “cameras” and navigation calculator/computer/AI is what makes modern missiles able to see further, and being distracted less by flares. Another difference is that you can have a camera that looks around like a human eye allowing the missile to lock and track targets on very extreme angles. Depends by the movie. The computer searches an amount of heat and its “frequency” on specific ranges. A missile computer will not chase the sun (too hot) or a little fire (too dim), it will not chase a flare if it doesn’t match the same target frequency (what in lightwaves we call color, exist also in infrared). Each heat source has specific frequency range, think about red orange and yellow fire. Very early missiles were simpler and easier to fool.",
"So not sure if this analogy works but. Let's say you're in the dark trying to find a friend. Say your friend shines a torchlight around you. You fix your eyes on the torchlight and walk towards the person until you reach him. In this case, your eyes are the infrared sensor in the missile's nose and the torchlight is a heat source (and aircraft engine/afterburner). You/sensor lock onto the torch/heatsource and guide to the target. Now that was just one heat source. In reality there are a lot more background sources of heat (the sun, heat decoys/flares countermeasures). Which can confuse you. So if another friend wants to trick you into guiding to him in the dark. He just shines another torch which might make you walk to him instead. Modern heat seekers like the Aim-9X/Python 5 are designed to be able to somewhat distinguish between decoys and the actual target heat source. Hope this helped!",
"\"Heat Seeking Missiles\" is an antiquated term. These missiles were designed in the 70-80's to follow certain heat signatures given off by afterburners and destroy something above a certain temperature. This was when 8 bytes was a lot of experimental software with no direction or backing. Movies make all of this look way more sophisticated than it is/was. [Chaff]( URL_0 ) wouldn't be an adequate deterrent if this was as smart as Bond films make it out to be. Newer tech within 5th gen fighters and drones basically make this worthless for future air battles unless they can detect missiles from much further away than current abilities."
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nwl9v2 | why are Tobacco/Cigarette/Vape Companies still so successful despite the laws and education against them? | Economics | explainlikeimfive | {
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"They're super addictive, broadly legal, and still have a presentation of being \"cool\". *Anything* that's all of those things will be wildly profitable.",
"Because smoking feels so goddam good, and is really shitty to give up. Problem at work that you cannot solve? Have a smoke break, and realise the solution, or just get away from the problem. Morning coffee? Better with a dart. Drinking? Have some durries. Dropping some E? Sooooo many cigarettes. Need to write some or are studying? Coffin nails help no end",
"Also keep in mind that cigarettes aren't as negatively stigmatized around the world as they are in the U. S. As a former smoker I can confirm that: 1) Smoking is cool when you are young. Argue if you want but when I was a kid this was a universal truth 2) Smoking releces stress 3) There's an addictive social aspect to being a smoker 4) Once you are hooked they taste GOOD",
"Welp nicotine is supper addictive. So if you are teenager and there is a craze about puffing big smokes and cool tricks, you jump on the fad. You don't really think about consquences cause that's not what most teenagers do. And now you are hooked. That's one example. Other ones are you smoked all your life and it's normalized for you. Plus nicotine is super addictive. In all honesty, nicotine should be illegal, like schedule one drug. Edit: deleted the swear words.",
"Because people like to smoke. People like the taste, people like the smell, people like the illicit effects, people like taking a break, people like smoking in groups, people like meeting other smokers. I'll be honest, I was 25 when it first dawned on me that smokers actually like to smoke. You know, despite knowing better, people like to drink, too, right? You've got binge drinking, drunk driving, alcoholism, liver damage, jaundice, and DUIs, and yet, people like to drink. Why can't they like to smoke? I don't know why it took me so long to realize that. And I was smoking casually by this point, too, still wondering why others smoked. It only matters that it's addictive IF YOU'RE TRYING TO QUIT, but... most smokers aren't trying to quit. They're not interested. They don't want to. It's not the addiction doing the talking, they actually like to smoke. Most smokers don't even start due to peer pressure, they start because they want to smoke. Smokers often say they should quit, but those aren't words of conviction - it's subtle, but it's what they know they're supposed to say to a non-smoker to get them off their backs. People like all sorts of drugs, knowing full well the risks beforehand. Education is part of any campaign to reduce any sort of drug consumption, but education is mostly ineffective. DARE was supposed to be an education campaign, more of a propaganda campaign, it's actually linked to an increase in drug use. I can't speak for vape, I think of it as the foofy cocktail of the smoking world. I can't speak for cigarettes, they're made from the lowest quality Burly tobacco and I'm better than that - it's like smoking shredded newspaper. I've tried hooka, and it's nice, and the only thing I've ever actually inhaled - I prefer smoking with actual bits of fruit in the tobacco rather than that juiced up tobacco stuff - you just don't know what that liquid shit is. I do enjoy a nice pipe by myself, or a cigar, and scotch, and a steak, with friends over a late summer evening. I've dipped, and that's nice, too, but take it from me, don't drink and dip unless you're a professional. This is one I won't make a habit of, because the chance of mouth cancer is just way too high. I've tried snuff aka snus, tobacco powder you inhale. Minty. Like dip, probably not something you want to do all the time. I don't like the high of pot and can't stand the smell. Everyone should try shrooms once in their life, I think it would make the world a better place."
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