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mehwre | if space is expanding every moment, does that mean things on earth also enlarge every moment? | Things are within space, and if space is expanding, does that mean everything on earth, tree, people, car are also expanding/enlarging every moment? | Physics | explainlikeimfive | {
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"No, things that are stuck together by electromagnetic forces and/or gravity (Eg earth/people/trees) won’t get bigger. Imagine blowing up a balloon with two ants standing on it. As the balloon (space) expands the ants get further and further apart, but the ants aren’t getting bigger. Same thing.",
"The \"dark energy\" of expanding spacetime is countered by gravity. So here on Earth, and really anywhere inside any galaxy, the gravity of the whole galaxy prevents expansion. The expansion happens in the empty space in between galaxies. The pull of gravity becomes weaker with distance, so those empty spaces have nothing to counter the influence of dark energy."
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mehybs | How do royalties work in music? | Do radio stations have to pay everytime they play a song by an artist or do the musicians get a percentage of download or CD sales? | Economics | explainlikeimfive | {
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"Radio stations, restaurants, bars, music venues...any business that plays music must pay a “blanket license” to do so. Those fees are collected by Performance Rights Organizations (ASCAP, BMI, Sesac) who are responsible for distributing those license fees to the artist’s whose music gets played. The artist or songwriter must be a subscribed member of these PRO’s and register their music to be eligible for royalty payments.",
"USA is different from most other countries in that only songwriters get royalties from radio play. If pretty much all other countries songwriter gets royalties and performer gets royalties as well. Depending who the artist registers with, there are different companies that to royalty collections. BMI requires all radio stations to submit a list of songs played. ASCAP just monitors what is played and generates statistics on what the most played songs are. For live performances, the 200 biggest venues in USA report their setlists and statistics generated from that. The tracking in general is quite poor and favours the established artist. If you are a small time artist who just gets a few radio plays, you'll probably be completely missed in statistics and get $0."
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meiptg | What's the winner of a fishing derby/tournament doing that the last place guy isn't able to? | Other | explainlikeimfive | {
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"Fishing involves some luck, some days fish just don’t bite. But a skilled, and more importantly experienced, fisherman will know what he needs to do to increase the chances of the fish biting. From knowing the fish, and knowing/finding spots you know will work well for those fish, to using the right bait and tackle that you know works well for that kind of fish. To reeling/pulling in in a way that you know will entice the fish to bite. But again, there is and will always be a luck component. They’re kinda like poker tournaments. A mix of luck and skill/knowledge."
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mej5h2 | how do my plastic bags end up in the ocean? | Other | explainlikeimfive | {
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"Assuming that chain is unbroken and working as intended, your bags shouldn't wind up in the ocean at all. However, every regions trash system is different, and they aren't always on the up and up. For example, if I throw a bag into the trash, its going to a landfill to be buried. If I throw a bag into a recycling bin its going to a recycling center. Ideally, that recycling center is somewhere nearby. However, there have been plenty of cases of poorer countries accepting trash and recyclables in exchange for cash. The trash company footing the bill is saving money compared to processing the trash and recyclables itself, and the poorer country gets money and a resource to be processed without all those pesky environmental regulations of worker safety rules. At that point, who knows what's happening to your trash and recyclables. They could be lost at sea during transport or thrown into the ocean by an unscrupulous trash processing center in the poor nation."
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mej80u | why does a phone’s battery keep working if plugged in just before dying, but takes a few minutes to turn back on if plugged in after dying? | Technology | explainlikeimfive | {
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"Because once the phone dies, it needs to boot back up. That boot up process is a bit more sensitive, a crash/the phone shutting down again during a boot up could possibly corrupt the files needed to run the boot. If that happens, you’re just dead in the water. So, smartphones will refuse to turn back on right away, allowing the battery to get enough charge that it definitely won’t die while booting up even if you unplug it again.",
"First, electrically, it takes more energy to go thru the startup process than to keep running. So a slow charge might be enough to keep it going but not enough to sustain a one-minute bootup. Second, electrically, all the components require a certain voltage range, batteries output higher voltage when charged, and voltage drops quickly under load\\*. So even if there's enough chemical energy in the battery to sustain a bootup, a near-dead charge level might not be enough to provide that energy at a fast enough rate. Third, on the software side, phone makers know about the first two reasons. So they program the OS (operating system, usually Android or iOS) to shut down cleanly when battery is critical and they program the firmware (the low-level code that handles stuff before the OS can load) to refuse startup until there's enough charge to be useful. \\*That is, idle voltage is higher than sustained voltage. This likely depends a lot on specific battery technology, and newer battery designs (and phone OSes) seem a lot better about this. My first smartphone had this so badly that I could do a high-intensity task (by decade-ago standards) for an hour, watch the stated battery level drop from 100% to 50%, close the app and turn off the screen, and check again in an hour to see 70% battery (not actual numbers, but nominal battery level did go up a lot while idling after a huge drain)."
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mejoxb | How does our body handle the calories from alcohol? | I can’t find a straightforward answer on the internet, maybe there isn’t one. From what I know there are 7 calories in a gram of alcohol, but our body also doesn’t directly use alcohol like it does the other 3 macros. It has to break it down into other substances to process it. Maybe a better question is, Can we treat alcohol calories like calories from the other 3 macros? | Biology | explainlikeimfive | {
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"Ethanol has to be broken down in the liver before it can be metabolized for energy. First, an enzyme called alcohol dehydrogenase converts the ethanol (CH₃CH₂OH) into a toxic and carcinogenic compound called acetaldehyde (CH₃CHO). Then, the Acetaldehyde is converted into acetate (CH₃COO^(-)) by a second enzyme called aldehyde dehydrogenase. Acetate, by the way, is the anion of acetic acid, the primary constituent of vinegar. Acetate is less toxic than acetaldehyde, and can be metabolized in the mitochondria like a carbohydrate.",
"Actual nutrition expert here: your liver prioritizes the processing of alcohol, since your body recognizes it as a toxin. So your body doesn't process any other food until the alcohol is gone. As a result, other food is stored as body fat or excreted. Which means alcohol calories have a system-wide impact. The calories in alcohol are consumed first, leading to other food you consume being stored as fat. Anyone telling you \"a calorie is a calorie\" has no idea what they're talking about."
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mejya6 | Why does lighter skin get sunburnt more than darker skin if white reflects sunlight and black absorbs it? Shouldn't darker skin get sunburnt more than lighter skin? | Biology | explainlikeimfive | {
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"What causes sunburn is not just absorption of light somewhere in the skin, but rather absorption of light by DNA spcifically. Damage to DNA can result in cancer, which is why in case of sunburn the damage is detected by the cell, causing cell to commit suicide (to reduce risk of cancer). Dead cells will cause sunburn, but that is far better than cancer. Dark skin has protein (melanin) that absorbs sunlight (actually, light skin has it too, but darker skin means much greater amount). That absorption results in a far lower chance of light reaching DNA and being absorbed by it. The protein then releases that energy as heat, which can be managed by just keeping the body cool. Even if a given melanin molecule gets damaged, it has no impact - since it is not damage to DNA it does not result in risk of cancer, o no need for cell to suicide, just make a new melanin molecule. Also, note that sunburn-causing suicide mechanism is imperfect, so someone who habitually gets in situations where they are sunburnt is at higher risk of skin cancer. So, use sunscreen.",
"Because white skin only reflects *visible* light. UV goes straight through and damages the cells. Melanin in dark skin absorbs UV which lets less UV through to the deeper layers. Less UV making it through means less damage occurs to the cells below the pigment layers.",
"The first thing to mention here is that \"white\" skin isn't white as in the color, it's just a very light, pinkish brown. But the same thing would probably be true if skin were *actually* white because that color reflects all *visible* light, but sunburns are caused by *ultraviolet* light. Both are on the electromagnetic spectrum but they have different energy levels (wavelengths). What actually protects you from sunburn isn't your skin reflecting light away, it's melanin in the skin (as /u/Scoobydoomed noted) which *absorbs* certain kinds of UVA light and prevents it from penetrating further and damaging skin.",
"Dark skinned people produce more melanin (pigment) which is very effective at neutralizing harmful UV radiation, reducing the risk of sunburn and skin cancer."
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mekihw | How is an NFT bad for the environment? | Technology | explainlikeimfive | {
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"So, the thing is that an NFT relies on computers doing computational work, consuming electricity to do so. Consuming more electricity means the power generation stations are doing more work, which releases more pollution into the environment."
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mekrj6 | Why do hive mind insects have a queen? | Almost all hive mind insects have a queen, why? Does it have to do with them laying eggs? | Biology | explainlikeimfive | {
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"For “hive mind insects”, specialisation is their strategy of survival. This is kind of like cells in our bodies specialise. Instead of being just a set of self sufficient cells, we have cells that can only extract nutrients, cells that can only defend other cells, and a small number of reproductive cells. Similarly, “hive mind” insects have dedicated roles, and individuals have anatomy that enables them to perfectly fulfil this role. Most hive insects that I know of have soldiers, workers, males and queens. Reproduction is an energy consuming process, especially for smaller species, so it makes sense for workers and soldiers to be sterile and not burn through energy, and focus on feeding the queen instead. The queen does nothing but lay eggs. Some hive species can have multiple queens per a nest, but in most of ants for example, queens that reach reproductive age leave their nests and found their own ones. This is because the region around the nest only has this much resources that the queen can consume. Overly simplified, this is for the same reason why fungi have spores and plants have seeds and don’t just grow infinitely. Note that, although this is a very viable strategy, and ants are a very successful species, this is not the only viable strategy. There are of cause species of insects that don’t specialise and don’t build nests. But when they do, reproduction is usually the first function that they separate, because it is very energy consuming."
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melo3h | Database Performance vs Latency | What's the difference between database performance and latency? | Technology | explainlikeimfive | {
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"Performance is a broader term, it includes things like latency and throughput and resource consumption and so on. Imagine a rubber tube that is connected to a fire hydrant. We can measure performance of the tube. Latency is: when you open a hydrant, how long does it take for the water to start flowing from the other end of the tube. Throughput is: how many liters of water per minute can we push through the tube. Resource consumption is: how much pressure the pump would need to apply to push that amount of water through the tube. In case with databases, latency is how fast you can get the response after sending a request, and throughput is how many requests per N milliseconds you can execute."
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meme3d | How do batteries hold their charge for so long? How do they work? | Technology | explainlikeimfive | {
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"Batteries contain chemicals that create electricity in some way or another. This is called electrochemistry. The electricity is harvested by the mechanism the battery is part of. There are many types of batteries, so exactly what type of chemicals and other materials they contain varies."
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memjc0 | How does both fission and fusion create usable energy? | Physics | explainlikeimfive | {
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"It has to do with the stability of the atom. Fusing two hydrogen atoms into a helium atom creates a more stable system, and therefore requires less energy. The excess energy is released. You can think of it like a company. If you hire more employees, it takes less energy per employee to do the same amount of work. But this only works to a certain point, beyond that point, adding more nuclear particles (or workers) to the system makes it less stable (efficient). The most stable (efficient) atomic configuration is iron. Atoms that are heavier than iron are less stable, and will therefore release energy when nuclear bonds are broken (fission). Atoms that are lighter than iron are also less stable and will release energy when forming nuclear bonds (fusion).",
"You've seen the periodic table of elements, right? Rearrange it in your head as a line with the lightest element (hydrogen) being at one end and the heaviest elements being at the other end. If you looked at the potential energies of each element, it would look like two mountains on either end with a valley in the middle. The lightest elements can produce energy by being combined with other light elements. The heaviest elements can produce energy by being split into smaller elements. The point in the middle where no energy can be gained is Iron."
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memjdr | what makes breast cells so much more likely to become cancerous than say the cells in our toes? | Biology | explainlikeimfive | {
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"Cell turnover. Primary heart muscle tumors are exceedingly rare. Why? Because once a heart muscle cell differentiates into a mature cell, it might make some adjustments throughout its life, but it doesn't divide to create a new heart muscle cell. There's a regular rate of turnover of the cells in your toe. Depending on the exact cell (bone-related, skin, nervous, immune) there are different rates of turnover, but once you grow an adult toe, there's not a lot of change taking place down there. Breast tissue is different because it isn't run on a single script. It gets an input from the body's hormones. Estrogen UP, breast tissue adjustment. Period time? Breast tissue adjustment. Baby time? Breast tissue adjustment. As a result there's a natural ebb and flow to the tissue, enough to generate a significantly higher rate of cellular turnover. Cut off the signal, mammary glands shrink up. Turn the volume up on the signal, mammary glands cells divide to provide for reproduction. (For the record, the prostate has a similar downside with hormonal input). Every time a copy is made, there's a chance for a clerical error in the code. The more copies, the more chances for errors, some percentage of which will be catastrophic. Go out in the sun a lot? Burn that top layer of skin often? More skin cells are required to replace the damaged cells. Higher turn over = increased risk of skin cancer (not to mention the sun radiation increasing the risk of damaged DNA copies). Over active immune system? Much better chance for an error to occur in an immune cell. Here comes the lymphoma.",
"Cancer is something that happens when a cell accumulates certain kinds of mutations that break the normal mechanisms of the cell, causing it to reproduce rapidly and evade the anti-cancer mechanisms cells have evolved, like spontaneously committing suicide when something happens in the cell that looks a bit like cancer. Some cells are more susceptible to mutation than others - cells that do more cell division have far more opportunities to copy DNA incorrectly or to make temporary mutations permanent (cells contain mutation repair mechanisms, but those can't repair mutations after DNA replication sets them in stone). Toe cells aren't really doing much. They just reproduce to replace any cells that die and to produce new layers of skin. Certain kinds of cell however are sensitive to the growth hormone oestrogen - when they detect oestrogen, they increase their rate of reproduction. This is true particularly of breast cells, but the same mechanisms are responsible for prevalence of cancer in many sexually dimorphic tissues, including the ovaries and prostate. This means breast cells are reproducing a lot more than toe cells, and the more oestrogen in the body, the faster they reproduce. This gives more opportunities for one or more breast cells to develop cancerous mutations. It also allows mutations in the cellular mechanisms that detect oestrogen to increase risk of cancer too, something cells without these oestrogen mechanisms don't do. Cancer is all a game of chance. It's like Russian Roulette - the more times you pull the trigger, the higher the likelihood you pull the trigger on a chamber that contains a bullet. Breast cells pull that trigger a lot more often than toe cells, by reproducing a lot more often.",
"Cells that divide more often are more likely to have uncontrollable divisions and accumulate mutations in the cell's DNA and cycle of cell division that cause a tumour to develop.",
"Some of it is genetics, some of it is cell turnover rates, carcinogens that are cell specific, dna mutations, higher concentrations of cancer promoting agents (hormones). Cancer is a mix of multiple bad things happening at once, and not much of those things happen in the toes."
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memnfu | What do the photons of laser light experience if two laser beams of equal power are pointed directly at each other? | Physics | explainlikeimfive | {
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"Photons are not particles in the strictest sense. They have no mass and do not collide with each other (if thats what you're asking). Photons are more of a mathematical model to describe certain properties of light. They can interact with each other in other ways (spooky action at a distance!) But they won't collide. Particle beams on the other hand will, which is why CERN is a thing. Side note: a photon traveling through a material with a potential equal to its wavelength can cause the material to release a photon of the same wavelength. This is called stimulated emission, and is the reason we have lasers in the first place. Fun fact: laser is an acronym that stands for Light Amplification through Stimulated Emission of Radiation."
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mendoq | How does ‘hive minded’ insects work? | Biology | explainlikeimfive | {
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"By using pheromones (or scents/smells). If one ant finds food, they give off a special scent that lets the other ants know there is food there.",
"They can communicate through tactile signals sounds and visual signals, but mostly through chemicals / smells. For example, ants leave smelly trails wherever they go. They also smell each other to recognise members of their own nest and distinguish them from enemies. In case of danger, discovering food and so on, ant’s body will produce certain smell to inform other ants.",
"There is no such thing as a, \"hive mind\". That's a concept from science fiction. Insects like ants don't share thoughts, they don't even HAVE thoughts."
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menjxl | Seedless Fruit. | Other | explainlikeimfive | {
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"Seedless fruit grows from plant cuttings or from spreading plants. They typically get seedless from crossbreeding. You can breed a horse and a donkey to get a mule, but the DNA doesn't quite match up and they are typically infertile. Same with plants.",
"They are sterile hybrids. You have to cross a male and female of two different strains in order to create them. Like crossing a horse and a donkey to get a mule."
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menqgf | How is light bent by gravity if photons have no mass? | Physics | explainlikeimfive | {
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"In the theory of General Relativity (GR), gravity is not a force at all, but a curvature of spacetime. To understand how a curvature of spacetime can lead to the effects we observe around us, we have to understand how curved surfaces change the behaviour of straight lines. First things first: an object that has no force acting on it is force-free. Force-free objects do not accelerate and, therefore, move along straight lines. In a flat geometry, two straight lines which are parallel at one point will remain parallel for all times. That is, two parallel straight lines will never cross on a flat surface. So far so intuitive, right? But what happens, if those straight lines do not move across a flat surface, but instead along a curved surface? We call such straight lines on curved surfaces [geodesics]( URL_1 ). Imagine a [sphere]( URL_2 ) with two lines perpendicular to the equator. As they are both perpendicular to the same line, they are parallel at that altitude. Imagine two objects that are moving along the lines perpendicular to the equator. They start out parallel, and move in a straight line upwards. Despite the fact that neither of them is turning, the two objects that started out moving along parallel lines will meet at the north pole. Hence, despite the fact that both objects are force-free at all times, they experience relative acceleration. Such trajectories, that lead across curved surfaces without turning are called geodesics and they can be thought of as straight lines on curved surfaces. Objects under the influence of gravity follow [geodesics]( URL_1 ). As gravity curves spacetime, geodesics can experience relative acceleration despite the fact, that both objects following said geodesics are force-free. And this relative acceleration of force-free bodies is what Newton mistook for the gravitational force. According to GR, though, there is no force, only curvature which causes force-free objects to move along paths that seem accelerated to outside observers. This explains why photons are affected by gravity despite having zero mass: photons travel through spacetime and spacetime is affected by gravity. ----- For a great video on the basics of GR, check out [this]( URL_0 ) video by PBS Spacetime.",
"Gravity bends space itself. And light just goes for a straight line. Imagine two parallel lines following the curvature of Earth from the equator to the north pole (it would help trying to do this experiment with a ball), because the surface is curved, the parallel lines eventually cross. This is the same effect gravity does to light."
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menqy4 | Why is it that the longer you spray a deodorant can, the colder it gets? | Physics | explainlikeimfive | {
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"Because as you expel the contents of the can, the pressure IN the can drops. Gas has a direct relationship between its pressure and it’s temperature. If you pressurise gas, it will heat up, infact, check out a ‘fire piston’, its a little thing you can hit that heats the air in it so much it will ignite an ember inside. In this case, the opposite happens, as you drop the pressure, the contents literally get colder. Refrigerators work in a similar manner - they drop the pressure of a circulating ‘coolant’, it gets cold enough to keep the fridge cool. In a detailed level, you’re squashing atoms closer together, they bounce around more, stretch them apart, they bounce into each other less. Atoms bouncing/vibrating around is one of the main reasons for things getting ‘hot’ or cold",
"The spray is driven by expanding gas from the propellant liquid vaporizing. Anything evaporating requires energy to change from the liquid to the vapour state so the remaining contents cool as they supply that energy. Sprays that depend on compressed air don't cool as much but will do so a little as the gas expands in a reverse of the process that makes a bicycle pump warm up as it compresses air.",
"Others have explained it well, but I’ll just add that the best example of this that I’ve seen is when I use my propane blowtorch to kill weeds (I have a bit of land with paths that need to be cleared and this works pretty well). The big can of propane is strapped onto a hand truck and the nozzle is attached via a hose that’s a good six feet long. So, the can never gets warmed by the flame. It just sits in the background while I torch weeds. Anyway, after continuous torching for a while, especially if it’s a humid day, the propane can will be encrusted in a layer of ice, even if it’s 75 degrees Fahrenheit outside."
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meo3ls | How does random mutation occur naturally, what triggers this process and how frequently? | Biology | explainlikeimfive | {
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"DNA copying isn’t perfect. Sometimes errors get made. That’s a mutation. Most of the time it doesn’t do anything, sometimes it makes things worse (e.g. cancer) and once in a very rare case it makes things better. And the ones that make things better tend to stick around and eventually can become dominant. You can also get changes from chemicals that are capable of reacting with DNA directly or can mess with the DNA coping process, those are called “mutagens” and increase the number of mutations. Some types of radiation are also energetic enough to trigger chemical changes in DNA. That’s called “ionizing radiation” and starts at about UV (why sunlight can give you skin cancer) and runs all the way up past gamma rays (why nuclear weapons can give you cancer)."
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meobet | Why do phones have to download text documents and other files that computers can open up in a new tab normally with no download required? | Technology | explainlikeimfive | {
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"If your computer shows the document in another tab then is has downloaded it. If it was not downloaded how could you show the information? You are confusing downloading with saving to the device filesystem so it can be opened with another program versus displaying it in the browser. The difference is that for some reason the browser on the phone does not have support for the file format you downloaded. Phone browsers os does not have the support for an external plugin like on desktops because having at least historically been on devices with less ram and processing power that are battery-powered. So the browsers have been more streamlined."
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mepqfb | Why do we use the energy released from nuclear fission to boil water instead of transforming it directly to electricity? | Physics | explainlikeimfive | {
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"When nuclear fission occurs, the reaction itself doesn't directly generate electricity. The vast majority of the energy created is in the form of heat. The most efficient way that we know of to convert heat into electricity is to use that heat to boil water and send the steam through a turbine.",
"The energy is released in the form of heat. And it's released in a diffuser manner, as in all directions. So our most efficient way to capture maximum is to surround it by water. The water becomes steam and that's what we use. To make electricity we need to spin a turbine and we don't have any other way to make heat directly turn a turbine",
"Nothing \"directly transforms\" into electricity in any sense, exception is solar power and the photovoltaic effect. Far as i know all other sources of energy have to be converted into something that can physically rotate generators."
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meptdz | How is it that bugs take no fall damage? | Physics | explainlikeimfive | {
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"Speed required to damage them is greater than maximum falling speed possible due to air friction",
"Basically same way we don't damage using parachutes. Some bugs have simply air friction and weight ratio that it's like having a natural parachute at all times. To a such bug, air is more like a liquid, so it falls through it like you would sink into a deep lake. Even if lake is super deep - like 15 stories deep, you still won't crash the bottom of the lake in the end, water slows you down so much all the way. Even though acceleration by gravity is same, water limits the speed you end up with (called terminal velocity) much more than air would. But if gravity was - 10 times stronger - say - on different a planet or whatever, you could totally splat to the bottom of such lake and water friction couldn't overcome it enough to save you.",
"If you get scaled down so you're half the height, you're 1/4 as strong, and have 1/4 the surface area, but you're only 1/8 as heavy. This continues the smaller you go. For a very small bug, you might have a surface area to weight ratio similar to a sheet of paper.",
"There's a very useful thought tool called \"squares versus cubes\". The idea is that if one property is proportional to the square of something, and another property is related to the cube of something, you can pretty much ignore everything else. In this case, the mass an object (an insect, in this case, but the same applies to all objects) is roughly proportional to the cube of its length, because stuff on the inside has mass. And the drag that an object experiences is roughly proportional to the square of its length, since it's only the leading surface that has to push through air. So the bigger a thing gets, the less drag matters, and conversely, the smaller a thing gets, the more drag matters. Bugs, being very small, are greatly slowed by the air they're falling through because the ratio of their mass (which gravity pulls against) to their area (which wind pushes against) is small.",
"They aren’t very dense so they don’t hit the ground very hard. In scientific terms, their low terminal velocity and lack of mass mean there is not much force on them when they hit the ground.",
"When you fall you push air around you. Feel it with your hand. The air is also pushing on you. When a bug falls, the air pushes against it too hard for it to go fast because it it so small and light. Drop a leaf and a rock, observe. Edit: Gravity pulls on the leaf and rock equally.",
"Late to this party but here is a video by Kurzgesagt explaining this very thing perfectly! URL_0",
"Their body can take the proportional impact force of freefall on earth. This is because of the square cube law. As an organism gains surface area by 1, it's volume increases 3. Smaller organisms terminal velocity with their mass doesn't create a disproportionate impact. If an object gets larger and maintains the same density, the volume of that object increases much faster than its surface area. Or, as the outside of something grows, the inside grows way more.",
"Smaller things are stronger relative to their size. Some effects and forces dominate at different size scales. Like how an ant can carry 10-50 times their body weight. And grasshoppers can jump so far compared to their size. And why bugs find water to be very gloopy. Suppose that a thing has length ***L***. It then has area ***L******^(2,)*** ***and volume L******^(3)***. Now imagine increasing L and see what happens to each. Area increases more than length, and volume increases even faster. Some effects may depend upon area, some on volume, and so the relative strength of these changes at different size scales. The mass and weight will scale with it's volume. But the strength the material it's made of will scale with area (think of the thickness of an iron rod). So bugs are very tough and strong for their weight. Also, the air resistance they feel scales with area, so they will fall slower and fly easier."
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meq4cr | what is a pyramid scheme and why is it bad? | Other | explainlikeimfive | {
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"You sign up and pay money, and then you try to get more people to sign up so they pay you money. You keep paying a cut to the person above and keep getting money as the people below you sign up more people. Think about the pyramid shape this creates: there's a small group of people at the top and they get rich because they get some money from all those people in the wide base of the pyramid that are signing up. It's bad because by design the large group of people in the lower part of the pyramid will lose money. It's not mathematically possible to keep doubling the size of the pyramid; the more layers you add you quickly you run out of people willing to sign up. The people at the bottom will never make back what they put in. So pyramid schemes benefit the people who think of them and promote them early on, and steal from the rest. That's why they're banned in many countries."
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meq5p0 | What determines thermal conductivity | Why is metal more thermally conductive than plastic, and why are some metals more thermally conductive than others? Why is diamond the most thermally conductive? What can you do if you wanted to change a material's thermal conductivity? If you wanted to make plastic more thermally conductive for example, what are your options? | Physics | explainlikeimfive | {
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"There are two main ways that heat can transfer through a simple material, as vibrations of atoms being passed along the solid lattice and as 'heat carriers' like free electrons moving through the material. Metals are so thermally conductive mostly because they have a large amount of free electrons which are able to carry heat (as well as electricity), some metals will have more or less of these. When you don't have free electrons then the lattice spacing and strength of the bonds will determine the thermal conductivity."
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meqkxn | Chess. How did people of 15th century create such a well designed game? | Other | explainlikeimfive | {
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"The people who designed it were just as clever as we are. [ URL_1 ]( URL_1 ) [ URL_0 ]( URL_0 ) Also, the game of go is 2500 to 4000 years old. And should have been in that list.",
"Chess developed over hundreds of years and the rules took a lot of changes as it spread across the world. There are a number of abstract games that have similar levels of balance and deepness despite simplicity. And we do create similarly deep games all the time. Abstract board games come out in droves. They simply don't have a few century long advantage over other games that get popular.",
"Lack of technology doesnt mean lack of intelligence. Lack of education doesnt mean lack of intelligence. You're not smarter because you can use an i phone. You're not smarter because you know basic biology or chemistry that didnt have explanations back then. I like to think of education as ones opportunity to learn and intelligence as one's ability to learn. They are independent of each other. We are certainly more educated than people hundreds of years ago but that doesnt mean we are collectively smarter. Intelligence is more about ones ability to solve problems and recognize patterns, and that trancends time and the knowledge that comes with it. TL:DR People weren't stupid back then.",
"The origins of chess go back to well before 1000AD. Shogi, which is known to have been played in the 11th century, is assumed to have a common root with chess. The base idea behind chess isn't all that complicated - a board with a couple of pieces that have different movement options. There probably existed different versions and variants throughout time, and those variants that worked well became the versions we know today. The original version certainly wasn't the game we know today. After all, both chess and shogi with similar but clearly different rules must've developed from it, so it definitely changed over time.",
"Chess wasn't designed at a specific point in time by an individual or group of people. It grew out of older games with similar but not identical rules, and over hundreds of years the rules gradually changed. There were always different variants with different pieces across the world. It was only relatively recently that the standardised modern form of chess came about, when people started playing it more competitively. People 800 years ago weren't playing the same rules we use now.",
"My first comment was removed for being so short, so I'll try to make this a little longer: A simple answer: Survivorship Bias \\[[ URL_0 ]( URL_1 )\\] Put simply, there have been many many games over the years. The bad ones suffered from dying out due to not being played. The good ones got a lot of play and became popular. Chess developed from other games which had survived well.",
"Actually people of 15th century didn't create this game. If you look at the hisory of chess you can see it is approximately 1500 years old. The actual predecessor of the game was originated from India, by the 7th century ad. From India it spread to Persia. After Persia was conquered by the Arab, the game became very popular among the muslim world. After that the game rapidly spread over Europe and by that time it went through a lot of changes. In Europe,chess evolved to it's current state in 15th century.",
"I would argue that chess isn't a super well designed game. There are much more interesting and better games that are currently being designed. I once heard it put like this \"good strategy games test how good at strategy you are. Chess just tests how much you know about chess\" and that's kind of true. The best chess players in the world are the ones who know the most about it. Board games are going through something of a renaissance right now and there are innovations all the time, and there are many games that I would say are better than chess at doing what chess does",
"> How was it designed in pre-computer era, and why can’t we create a turn-based strategy that would be as deep and balanced? We definitely do they're just not as simple or widespread.",
"We, in modern era, design our games over 2-8 years generally. Chess had thousands of years of evolution. If we'd start designing a new game today, use nearly entire humankind for beta testing and shaping the concept, and took 1-3 thousand years to perfect it, I'm quite sure we'd come up with something quite well designed as well. Chess had popularity, audience and a *lot* of time."
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mer2iy | Why does pressing on the brain keep it from doing the thing that area is supposed to do? Is brain function dependent on open spaces somehow? | Biology | explainlikeimfive | {
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"Are you talking about pressure from tumors or blood vessels? Mostly because it disrupts blood flow - and without proper supply of oxygen brain cells can’t function.",
"I assume you're talking about a tumour compressing a part of the brain? Brain function is quite dependent on neurons (brain cells) being able to communicate with each other. This is accomplished through parts of the neuron known as axons, which are like wires that transmit an electrical signal. If these axons get compressed, neurons cannot transmit (or receive) these signals, which leads to a part of the brain being unable to carry out its function. Also, as pointed out before, if the tumour compresses a blood vessel, the neurons supplied by that blood vessel can die or be temporarily disabled due to lack of oxygen and glucose, which also compromises the function of the brain."
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merc9n | What is the process that is happening which makes eyes look glassy (when high etc.)? | Like I get that blood vessels dilate and that’s why they go red, but what is the bodily process that’s occurring which makes them look glassy? | Biology | explainlikeimfive | {
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"Similar to how marijuana makes your mouth dry, it also drys out your eyes. When the eyes get dry, we form temporary little microscopic scratches on the surface of the cornea, which is the clear dome over the eye(that covers the colored part of the eye). Tears are important to coat the surface of the eye. There are two types of tears: Basal and Reflex. Basal tears are secreted and spread continuously by the eyes 24/7 and keep the eye surface moist. Reflex tears are those which are produced by pain, external stimulus or irritation. In the instance of marijuana, your body senses irritation from the dryness/microscopic scratches and produces reflex tears. These reflex tears are analogous to the “emergency tears” and are produced in much greater volume that the basal tears. Your eyes look glassy because reflex tears pool near your lower eyelid. The dilation of the conjunctiva blood vessels are the cherry on top"
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mergfo | why was cocaine used medicinally in the past and why did it stopped being used? | Biology | explainlikeimfive | {
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"It’s a local anesthetic, which means it blocks nerve receptors and basically prevents you from feeling pain in the small areas it is applied to. I’d imagine it fell out of favor due to negative views surrounding its use and the development of other, more suitable alternatives (but I’m not a doctor). It is still approved for medical use and is typically used for nose/mouth surgeries due to its absorption and affect on tissue/membranes in those areas.",
"I work in an Acute care pharmacy (Inpatient Hospital Pharmacy). While not everyday, Cocaine is used regularly in the O.R. I'm no authority, but I've been told it is one of the most effective anesthetics. There are a limited, but not uncommon uses for it. Cocaine is a D.E.A. schedule II, not illegal, but highly restricted and controlled. Similar to morphine, oxycodone, Adderall, etc."
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mes5wd | How do prosthetic limbs/joints work? How is one able to move and control something that is just attached to them? | Biology | explainlikeimfive | {
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"Eli5: the parts of your body which do the moving, like your muscles, stay where they are and keep their function. A protstethic joint really only replaces the articulating parts of the construct. That means your muscles and ligaments stay where they are (minor loses due to surgery are to be expected) and keep their functions. This hasn‘t always been the case but nowadays due to minimal invasive surgery, you often only lose about a 1/4 of your joint capsule and muscles just get shoved to the side so the surgeon has access to the joint. You do in fact have to have rigorous training after getting a knee or hip replacement to have the full range of motion in the long run, which some people don‘t take serious enough. Source: physical therapy student who recalls something very tired at 8am on a sunday."
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mes75f | how are we running out of helium? | Other | explainlikeimfive | {
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"Helium isn't easy to work with. Helium is produced inside earth by radioactive decay, it rise us since it's light and get trap inside natural gas pocket. This is why we get the helium as some pocket can contain up to 1 or 2% of helium. But not all natural gas pocket have such an high amount. Helium is also the only material that physically leave the earth, as once it reach the surface, it will eventually get lost into space before it's light and not reactive like hydrogen which bound to other atoms. Finally, helium is hard to keep in large quantity, most container will slowly leak. There is way to keep small quantity of helium, but for large quantity like for storage, any methods is very expensive to build. So helium always went through shortage which boost the price, then it become profitable to extract more of it from natural gas, the price go down, and the cycle continue. Until the 60s, during which helium was needed for the space war and so the US government created huge storage area at high cost and gave contract to 5 company to produce helium to fill those storage. But eventually the storage were full, the space race ended and so the demand for helium dropped while the US had a LOT of helium in storage. So they just sold the helium cheap, making production of new helium too expensive to compete. Since then the storage is slowly getting emptied by the increased demand for helium in high technology, the price slowly go up and people slowly start production of helium, but never at the speed it was when the US government spent a lot on money on it. The issue is that in the past we didn't stop using pocket of natural gas with high helium, the natural gas was still important to extract, helium was just a waste by-product with little value at the time. And with more emphasis on green source of energy, there isn't a lot of natural gas pocket with enough helium right now. Currently the produce of helium can't go as high as it used to, so we don't know if we can produce enough helium to fill all the current demand. At the same time the US storage of helium is getting close to be empty.",
"We're running out because Helium is a non-renewable resource. There's no cost-effective process for making helium on its own, so nearly all of our helium comes as a byproduct of making other things.",
"Helium is less dense than air. So the same reason we use helium in balloons (and when we let them go, they go up up and away) is the same reason why we are fighting a helium shortage.",
"Helium is a byproduct of oil and gas extraction, and the US stockpiled huge amounts for years. The price has remained low due to the stockpile, and as a result helium recovery from hydrocarbon wells basically just stopped. The US have been selling off that stockpile for the last 10-20 years. Recovering more helium will start again as the price rises and it becomes economically viable again. The days of helium party balloons are rapidly coming to an end though.",
"Easily-mined helium. Helium isn't really that rare, but helium that's pretty easy to get to (and thus much cheaper) is becoming more rare."
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mes9sq | due to the massive amount of neurons in the brain, how is it possible that electrical signals don't crosspost (don't mind if I do) from one axon to another? | Electrical signals are transmitted in the most superficial outer layer of the axon (along the myelin sheath) or, at least, that's what I've been told at school. Is this (if any, ofc) one of the reasons why human thinking is so complex? | Biology | explainlikeimfive | {
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"They sort of do. A neurone that transmits an electrical signal increase the chance that other neurones will fire. And yeah, that’s another reason as to why we’re really complex. An extra tidbit, neurones are not binary; 1 or 0. They are are more like **potentials**. So, when a neurone fires it does not mean that other neurones will fire, it only **increases the chance that other neurones fire.** That’s probably why humans are so freaking diverse. Aa 0.004 difference in the time it took for a neurone to fire can make a **very big difference** in the result of an action.",
"The distance between axons of different neurons is a lot bigger than the distance between individual jumps between the Ranvier nodes of the axon, the gaps in the myelin sheath. I doubt there could really be any kind of arcing across neurons given that. Additionally, axons aren't wires: they carry electrical charge, but not in the way that computer chips do, and so they can't tally transmit across the space between axons."
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meshwr | how the eff do magic erasers work so much better than soap and water? | Don’t understand how they work so much better. | Chemistry | explainlikeimfive | {
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"*’Magic Erasers’* are actually extremely fine grit sanding sponges with a cleaning detergent included. A porcelain toilet bowl that has major staining like rust can be cleaned quite easily with a pumice stone. It’s the same concept with these *’Magic Erasures’*. Both the pumice stone and the erasers are actually removing stains by sanding them off. Note: I can’t be certain about the level of efficacy the detergents used in the erasers have in removing certain stains so I won’t speak to that.",
"They work more like sandpaper than detergent. For those who know and might even care, they have a Mohs hardness of around 4 and a grit of 3000-5000 depending (they're not the thing to use if you want precise polishing).",
"Part of it is the slightly abrasive material! As it breaks down, the grittiness helps removes stains/dirt. I learned this by going in too hard on a wall and removed paint by scrubbing too intensely lol. I am sure the chemicals help break down messes somehow but I don’t know the science or anything."
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mesjw9 | Why are video games required to provide seizure warnings but movies are not? | Technology | explainlikeimfive | {
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"Movie theaters have been offering warnings and sites also have warnings. A lot of gamers play in dark rooms with their eyes right next to the screen. There's a difference in how people consume media.",
"Might depend on the country you're in? In NZ there are warnings for movies.",
"Because video games are under a lot more scrutiny. Surprisingly, they still carry a lot of stigma, and need to be a lot more conscious than something like a movie, which, relatively speaking, can do whatever it wants. A similar example is the way parents frequently freak out about M rated games existing, but not so much about R rated movies. It is absolutely an example of a double standard, and the culture still adapting to a newer medium. Back when movies first introduced sound, the same sorta stuff happened."
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mesnco | How exactly do cpu and gpu 'improve'? | How do they improve? for example what is the physical difference between RTX3080 and GTX1080? | Technology | explainlikeimfive | {
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"There are basically 2 ways to make a CPU or GPU perform faster: 1 - get more computation done in one clock cycle 2 - get more clock cycles per second. You can achieve #2, just by making the clock chip pulse at a higher frequency. But faster pulses will a) consume more power and generate more heat, and b) push the switching components closer to their error threshold, where you might start to see them output the wrong values. So to keep increasing the clock rate, you need to keep inventing transistors and logic and memory components which can switch more precisely, in fewer nanoseconds, and you need to keep coming up with better ways to suck more heat energy out of a little tiny hot microchip. You can achieve #1, either by adding more CPU cores to the device so that each one can work on its own math problems at the same time, or by changing the CPU architecture - perhaps by adding a new instruction which does what you used to do in three instructions. Those are the main ways that CPU and GPU performance improves generation over generation.",
"More transistors in the chips, more cores, and making those cores run at faster speeds. Cooling solutions and power delivery can also be improved."
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meszdf | how is the james webb space telescope able to see billions of years back? | Other | explainlikeimfive | {
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"text": [
"The speed of light is a constant. The further you look away from Earth, the longer that light took to get to us. So if you can see billions of lightyears away, that light is from a time billions of years ago."
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met4jm | Why do women deal with eating disorders much more often than men? | Aside from societal pressures to look a certain way, why are women seemingly predisposed to eating disorders? What’s the actual science as to why this is the case? | Biology | explainlikeimfive | {
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"It probably has more to do with men not reporting these issues due to cultural expectations or eating disorders tending to present in different ways l, rather than men not getting them.",
"I don't think they are. Anorexia may be more common in women but obesity is also an eating disorder and is more common in men."
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meta1z | What is www(World wide web) and how is everything stored on it? Does it have any data limit. Is it like a big drive or something like that? | Technology | explainlikeimfive | {
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"text": [
"The internet is a bunch of computers with information in them, connected by a network (wires and devices designed to communicate information by sending electricity over said wires). The web is a sub-part of the internet, computers designed to present information as websites. As opposed to information presented as text chats, or game downloads, or movies, or other forms. Basically it's just computers sending information to you, when you click on things or go to a site. EDIT: The data limits are determined by the companies that own these server computers. For example, the Reddit company probably has a data limit; they're only willing to pay for so many computers to hold all these subreddits with all the text we type, it's not infinite. Microsoft, Amazon, Ebay, other companies have their own server computers and their own data limits.",
"The World Wide Web, or colloquially known as the Internet, is a network of computers on a wider scale. When you go to a website, what you’re actually doing is connecting to a server (or collection of servers) via an IP address (which a website name like URL_0 is translated through a domain name service, which is altogether a different subject). Everything stored on that server is done through the conventional means through some sort of media like a hard drive or solid state drive. Technically, the only limit the servers have in regards to storage is what each of these hard/solid state drives can hold. Since there’s so many of them, it’s near limitless. So, no, it’s not all one big drive, but thousands (if not millions) of drives all connected to this one huge network.",
"It's a bit more complicated than that. The way the Web works is that each individual website can be stored on a different server--in some cases a server will have multiple web sites on it, but mostly they're all separate. When you type a URL (e.g. [ URL_1 ]( URL_0 )) into your browser, the first thing it does is do a \"DNS lookup\" to find out what the actual IP address that corresponds to (it's similar to a street address, but for the Internet)--it then sends a request to that address for the web page, and hopefully gets a response. It's possible for a single server to have multiple websites on it, in which case, it figures out which one to send back by looking at the URL, which is sent as part of the website request."
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metr34 | Why or how would someone have an allergic reaction to a booster shot? | For example: I received my first Moderna vaccine and did not have an immediate reaction. I did get very sick and develop and rash a week later. Yesterday, I received my second vaccine and within twelve minutes started having an allergic reaction. My entire body was on fire and my throat and tongue were swelling. They used an epipen and sent me to the hospital. What happened between the first dose and the second dose? Why would the body react so differently? It was absolutely terrifying. No one has been able explain why I didn’t have a reaction the first time. | Biology | explainlikeimfive | {
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"Two pieces to this one. First, vaccine ingredients. In addition to the actual viral part of the vaccine, there are other things in there (not like crazy conspiracy theory nonsense, but like things that basically help extend the shelf life, increase effectiveness, etc.). An example is that the flu shot uses egg byproducts that people absolutely can be allergic to. Second, allergic reactions vary in severity each time (and in my experience tend to be worse each time). You can also develope an allergy as time goes on. My guess would be you were already allergic to one of the ingredients in this drug, you got off relatively light with the first shot, and are getting a full blown allergic reaction on the second (maybe even because some amount of the first is still in your system and so you're getting even more).",
"Not a doctor, but it sounds like an allergic reaction. You didn’t react to the first dose because you weren’t sensitive to it yet. Some people become allergic to certain substances over time with more exposure. Some never become sensitive, no matter the amount they are exposed to."
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metryl | Why does sticking your finger in foamy soda cause the foam to recede faster, but the same is not true of beer? | Chemistry | explainlikeimfive | {
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"It does work with beer to a certain extent but the foam on beer is much more structured and dense than with soda. It’s the oil on your skin that breaks down the foam and your finger just doesn’t usually have enough oil on it to break down beer foam. You can rub your finger on your nose to pick up a little more foam. That sometimes works."
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mev3gn | What is the physical meaning of wavelength of object? | Physics | explainlikeimfive | {
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"Objects don’t have wavelengths, only waves do. Waves can move through physical mediums (like ripples through water), or they can be part of a phenomenon like electromagnetic radiation — where the wave is a sort of physical effect that drives its own motion and does not have to be travelling through anything at all in order to move. In either case, the wavelength is the distance between two peaks (or two troughs), ie. it is the smallest repeating unit of a wave. If you meant what is the **wavefunction** of a physical object, well.... that’s a whole different thing which is firmly within the realm of quantum physics."
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mevf2i | - Why drive at right angles when encountering a tornado? | Multiple sources recomend this if you're in your car while seeing a tornado... If you see a tornado heading east, you're supposed to drive south (which is a right angle away from the tornado). Why not drive any direction that isn't east? | Earth Science | explainlikeimfive | {
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"If a tornado isn’t moving laterally relative to you, it’s either going towards or away. And you have no way of knowing; so driving at a right angle relative to the tornado will allow you to see which direction it’s moving.",
"I think what they means is to get out of the way of where the tornado is going as well. It will almost certainly be faster than you so you're safer sidestepping it than outrunning it",
"This advice is assuming the tornado is moving in your direction. They are saying don't outrun it, just get out of the way as fast as you can.",
"Tornadoes, similar to trains, are incredibly difficult to tell speed when faced head on. It's like trying to get out from under a falling tree: if you go straight away from it, it will still hit you, just later.",
"If you drive west, you will be heading straight into it, so I guess that’s out of the equation straight up. Heading east, you need to move faster than the hurricane. What car are you driving? It needs to move east at a faster rate than the hurricane, which the whole time, is still following you. If you stop, it will catch you. No matter how fast you drive, you will stay in the path of the hurricane. Now lets examine the two remaining possibilities. If you travel at right angles, you are moving away from the path of the hurricane at the fastest possible rate. After travelling 10 miles, the path of the hurricane is 10 miles behind you. You’ve escaped. If you had travelled east, the hurricane would still be following you, catching up, getting closer.",
"I don’t wanna act like I’m a tornado scientist but I would just turn around?",
"You know how when the action hero (like Indiana Jones) is being chased by a huge rolling boulder behind him, and everyone's like: \"dude why are you trying to outrun it, just take 3 steps to either side\"? This is like that. Your options of escape would be: * towards it -- > bad of course * directly away from it -- > also bad because you have to be able to outrun its advancing-speed. And because it's very hard to tell whether it's coming directly towards or away from you. It might be coming right at you when you think it's going directly away. * At right angles (in either right-angle direction) - avoids the possible towards/away confusion, and you no longer have to match its speed and outrun it. Just get out of the way and let it roll by."
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meviui | How were CDs and DVDs professionally made? What computers, software, and printers are used? | Technology | explainlikeimfive | {
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"They use a clean room and production line. Sound typically came from digital audio tape (in the '90s) and was then transferred on a glass disc called a master, using lasers. This master was then plated with metal to create a stamper. This entire process was relatively slow and took place in a clean room. The stamper was used to mould large amounts of cds (which are made out of plastic) on a production line. This is a quick process that only takes a few seconds per cd. Afterwards reflective material was dampened on the disc and the disc was coated with lacquer for protection. It is a different process compared to burning cd-recordables, as recordable discs have a layer with organic dye that can be burned using a laser. This also gives cdrs their distinctive color."
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mevosc | How do the new grocery scanners work where you just put stuff in a box do they work similar to book scanners | Link to what I mean URL_0 | Technology | explainlikeimfive | {
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"Typically, and this isn't necessarily the case in that one (simply because not there to see it), is something called an RFID tag. In short an RFID tag is coded with specific information, and when put near certain transmitters will send back whatever information is on the tag. This is often used in key fobs and security tags at stores."
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mevu4e | Why does fire make the extinguish sound when doused in water? | Chemistry | explainlikeimfive | {
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"It’s not the fire, it’s the sound water makes when a lot of it turns into steam all at once.",
"The \"PSHHH\" sound you're thinking of is not actually from the *flame* that you can see going out, but rather the *water* boiling off as it touches the super hot burning wood.",
"Heat up a frying pan on the stove and carefully pour in a little bit of water. That’s exactly what’s happening when the water hits the burning material."
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mew3ff | Why do PS5 and Xbox sell their new consoles around the same time, is it something they agreed upon? What other examples of this are there in the world? | Other | explainlikeimfive | {
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"They are kind of forced too. The one that achieves market dominance wins. That means the one who comes out first in a generation has a huge advantage. So, when one says a release date then the other has to match it. Even if their machine is not quite ready or their supply networks aren’t quite in place.",
"They didn't make any sort of agreement. Just that if one sells much later than the other then they'll miss out on a bunch of sales. And you'll notice both sold near Christmas to get in on that holiday season money which is why its around the same time",
"I think the development cycle is relatively similar, and also probably agree on a certain amount of time to give their previous console enough time in the spotlight. Other than that, one guy announces they’re gonna release their new console on a certain date and so the competition doesn’t want to give them a big head start so they release within a year.",
"Few reasons here. 1) To try to win the market. As has been stated by others, timing is everything. Xbox 360 is a good example. It was released about 1 year before PS3. Both had good followings but it seems to have won the popular vote. PS3 was a great console and (IMO) the better console but 360 had the player base and recognition built to hold the market. Sony won't make that mistake again. 2) It's expected by the consumers and the media. Game news loves the \"console wars\". It brings them a lot of traffic, ad revenue and affiliate link traffic. 3) Game Developers. Where do you think a AAA studio is going to put their primary resources: old hardware running 1080p @ 30fps or new hardware running 4K @ 120fps. Of course, this is just an example but every new generation brings new features that will attract developers which in turn brings players to the next-gen console. 4) FOMO (this kinda ties in to the previous points) Brand loyalty. Many/most gamers are loyal to their chosen console producer. But, FOMO (fear of missing out) is real and Playstation fans started to jump ship when 360 was released a year before their chosen console and because of this, many Playstation loyalists jumped ship to play with the newest hardware and their friends who swapped over to Xbox. There may be other reasons but they can all be summed up to the [same thing.]( URL_0 )."
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mew65k | does a lot change in the universe from one Planck to the next? | Physics | explainlikeimfive | {
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"What do you mean? Do you mean in how objects at that size behave? Well, yes. Quite **a-lot** changes. They behave *weirdly*. At that size, objects go from physical items you can touch to probabilistic waves. In these probabilistic waves, the object is in every place at once but is more likely to be closer to the center. When a light photon hits the wave, the wave collapses and becomes a physical object that can be seen and touched (observed). This is what physicists mean when they say the wave has been **observed.** This has been immensely simplified. If you’re ready for the more complex side of things, it’s more that this is a **thought or logic** experiment. So, basically, it’s not true, per say, it’s a scientific way of saying: Jim: “Hey, we can’t see these objects until a light photon hits them right?” Jack: “Well... yeah?” Jim: “So.... in that case, they could be anywhere at any time.” Jack: “Well. Yeah, pretty much” Let me know if this makes sense to you. Also, if anyone can chime in and let me know if I’m wrong, that’ll be great. I love to learn"
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mewblv | Why does rubing the ends of a cucamber make it taste better? | Other | explainlikeimfive | {
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"Well there is more to it then just “rubbing the ends” but essentially you are releasing a substance called cucurbitacin. Cucurbitacin is very bitter and most of it is stored in the tip of the cucumber. (Prepared for NSFW sounding things that are actually accurate in regards to culinary techniques) When you cut the tip and then rub it, a white substance(cucurbitacin) is released and you are ultimately removing the bitterness."
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mewtqy | Why does hot water feel nice on the human body but not hot air? | Biology | explainlikeimfive | {
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"When in a jaccuzi it won't feel nice when you're completely submerged (imagine having some sort of breathing apparatus), because your body won't be able to regulate its temperature. Usually your head and a part of your torso will still be above the water, and when you get uncomfortable you can get out of the water. On a hot summer day your body is surrounded by heat, and when that temperature is higher than your body - you won't last long.",
"Hot air makes you sweaty or dries you out. You usually don't choose to hussle around in hot air while you choose the hot tub for relaxation. Also some people like ~~chilling~~ hanging out in the hot sun. It just depends what feels good at the moment.",
"I love sitting in front of heaters and spending time in saunas. I also love hot summer days. So your question is personal, not universal to \"the human body\".",
"Many people actually do like saunas. I don't get it either, but numerous of them have insisted vehemently that's it's true.",
"I entered a store from the cold outside. As I walked around, I felt warm air from the heater come down onto me. It felt great.",
"sometimes it is nice to have the sun beating down on you when you're just relaxing, it can be soothing too, but it's the sense of not being able to escape the heat that people dont like"
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mewzyt | What are Tensor and CUDA cores? | Need help understanding what exactly Tensor and CUDA cores are and what they do in graphics cards | Technology | explainlikeimfive | {
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"[Based on this answer in stack overflow]( URL_0 ) They're both essentially just a part of the GPU that is really good at a certain type of calculation. CUDA cores are good at multiplying two numbers and adding it to another number. Meanwhile, a tensor core is specialized in doing the same but with 4x4 matrices instead. Both of these types of calculations are heavily involved in rendering traditional raster graphics. They also happen to be very useful in machine learning, which is why you'll often see GPU used for AI"
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mexb5o | Can someone please explain how you can unify belts in boxing? | I'm not a huge boxing fan but i sometimes watch very hyped fights. And i saw that there are several federations (IBF, WBO, WBA...), each with it's own belt. And i know that boxers fight in a weight category. How come that some boxers are only WBO champions and others hold belts from multiple federations? | Other | explainlikeimfive | {
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"Because boxing is a dangerous sport, bouts are generally staged either under the supervision of the authorities, or under the supervision of a private company that is licensed by the authorities to supervise fights. Fundamentally, that's what the WBO, WBC, IBF etc are - private companies that are licensed to supervise boxing matches. It's important to understand what these organizations are, specifically that they aren't leagues or whatever. A boxer doesn't fight for the WBC, or fight in the WBC, or under contract to the WBC. Instead, individual promoters arrange fights and as part of the arrangements, they find a sanctioning body that is willing to supervise the fight. A boxer might fight a WBC supervised bout and then their next fight might be supervised by the IBF. That said, many of these supervising companies maintain rankings of boxers. If a particular company (the WBC for example) is asked to supervise a fight between their two highest ranked boxers, they will typically award a title belt to the winner. If however, these same two fighters arrange a fight supervised by someone else (say the WBA), then the WBC won't award anything. In this way, boxers generally only win a single title at any one time. And, of course, a sanctioning body might choose to supervise a fight but not award a title to the winner if they so choose. So to unify belts, you must first become the second ranked fighter for two separate supervising bodies. Then you arrange to fight the current champion of one body in a bout that is sanctioned by that body. You follow this up by fighting the current champion of the second sanctioning body in a fight supervised by that body. If you win both, you unify the belts. The belts, however, don't stay unified. If you are currently the holder of two title belts (for example, WBA and WBC) and you arrange a fight with a second ranked fighter, you might choose to have the WBA supervise the fight, in which case the challenger can only win your WBA title (deunifying the titles). Or you might choose to have the WBC supervise with similar outcome. Or you might choose to have the fight jointly sanctioned by both the WBA and the WBC, in which case the winner stands to win both titles."
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mexfjz | How do magnets magnetise other objects? | The other day I had a metal spelk in my finger, and couldn't grab it with my tweezers so had to attach a magnet to it them to pull the spelk out. The atoms in magnets are angled in the same direction which is what gives it the magnet the magnetic effect, but how does this make other metals magnetic without changing the atomic structure of the metals and why does it only work on some metals and not all? | Physics | explainlikeimfive | {
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"Making something into a magnet is about alignment of the areas, as you already described. Transition metals have incomplete d orbitals and each orbital can fit 2 electrons of opposite spin (think of it as an arrow pointing up or down). As a result, the alignment of the electrons determines whether a metal is: - ferromagnetic (always magnetic, always aligned) - diamagnetic (all paired, only opposing magnets) or - paramagnetic (has unpaired electrons which align under a magnet but not otherwise). Some other variations exist, antiferromagnetism for example. Again, under the influence of a magnetic field, the electrons will align (spin direction).",
"Some metals have the ability to re-orient at the level of the atom (or magnetic domain) without screwing up or being restricted by the lattice/crystal structure of the material. The physics just says that getting \"magnetized\" is possible. The atoms can stay bonded to each other even when the magnetic field forces the atoms into a higher energy state."
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mexgnw | someone please explain Standard Deviation to me. | First of all, an example; mean age of the children in a test is 12.93, with a standard deviation of .76. Now, maybe I am just over thinking this, but everything I Google gives me this big convoluted explanation of what standard deviation is without addressing the kiddy pool I'm standing in. Edit: you guys have been fantastic! This has all helped tremendously, if I could hug you all I would. | Mathematics | explainlikeimfive | {
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"I’ll give my shot at it: Let’s say you are 5 years old and your father is 30. The average between you two is 35/2 =17.5. Now let’s say your two cousins are 17 and 18. The average between them is also 17.5. As you can see, the average alone doesn’t tell you much about the actual numbers. Enter standard deviation. Your cousins have a 0.5 standard deviation while you and your father have 12.5. The standard deviation tells you how close are the values to the average. The lower the standard deviation, the less spread around are the values.",
"My explanation might be rudimentary but the eli5 answer is: Mean of (0,1, 99,100) is 50 Mean of (50,50,50,50) is also 50 But you can probably see that for the first data, the mean of 50 would not be of as importance, unless we also add some information about how much do the actual data points 'deviate' from the mean. Standard deviation is intuitively the measure of how 'scattered' the actual data is about the mean value. So the first dataset would have a large SD (cuz all values are very far from 50) and the second dataset literally has 0 SD",
"ELI5: It's literally just tells you how \"spread out\" the data is. Low SD = most children are close to the mean age High SD = most children's age is away from the mean age === ELI10: it's useful to know how spread out your data is. The simple way of doing this is to ask \"on average, how far away is each datapoint from the mean?\" This gives you MAD ([Mean Absolute Deviation]( URL_0 )) \"Standard deviation\" and \"Variance\" are more sophisticated versions of this with some advantages. Edit: I would list those advantages but there are too many to fit in this textbox.",
"At one restaurant they cook their steaks perfectly every time. At another restaurant it's a crapshoot whether your steak is served raw or burnt to a crisp. At both restaurants the average steak is cooked perfectly. The first restaurant has less variance/less standard deviation and the second restaurant has greater variance/standard deviation.",
"In your data set you have an average age of 13. The standard deviating is close to one. This means that, in the group, you'll have some 12 and 14yo kids, too. If the standard deviation were like 5, you could have an average of 13 still, but also have a bunch of 8 and 18yo kids.",
"1) you have a mean, the average of all the data points in your set. 2) each one of those data points will have a variance between themselves and the mean. 3) you'd like to know what is the average amount of variance of those data points from the mean. That's it. That's the standard deviation. The stuff about what it means for a normal distribution can come later.",
"When you add and subtract a standard deviation to the mean, 68% of your data (age of participants) is within the interval. That's from 12.93 -. 76 all the way to 12.93+.76 If you add and subtract two standard deviations, 95% are within the interval. That's from 12.93 -2 * 0. 76 all the way to 12.93+2 * 0.76 If you tested another group and you got stdev > . 76 it would mean that the new group is more diverse, the ages are more spread out. Conversely, if you tested a group with stdev < . 76 it would mean that their ages are more close to the mean value, less spread out.",
"So far the answers you’re getting seem to only apply to the normal distribution (bell-curve) which is kind of misleading, since not all data is normally distributed and we use standard deviation in any case. At its core, standard deviation is a way of telling you how spread out your data is. Of course there are other ways of doing this (range, average distance from mean etc.) but standard deviation has some nice properties that we like. The best way of thinking about it I’ve found is geometrically. If you take a sample of n values from a distribution (such as the age of children in your example) and plot this as a point in n dimensions (so the first value is the first co-ordinate etc.) and also plot the point that has the mean in every co-ordinate, then the expected distance between those points is the standard deviation. In the case of a single dataset, you are computing exactly the distance between your data as a point and this mean-point. We like this because this is exactly the value that the mean minimises - if you took any other value as the mean then this distance would be bigger.",
"Thanks, from reading the sum of all these comments and averaging the answer I actually understand :)",
"The mean is the average of all the values. The standard deviation is-in effect- a measure of the average distance of each value from the mean. It takes the sum of the distances from each value to the mean squared, divides by the number of values, and takes a square root. In basic terms, a small standard deviation means most of the values are close to the mean, while larger standard deviation means the values are more spread out away from the mean. Almost all the other answers here are explaining SD in terms of normal distributions (“the bell curve”). No five year old needs to learn about normal distributions to understand SDs.",
"OK, let's try this: You have to make ten hamburgers out of 1 kilo of meat. Each burger should be 100 grams, right? So you form up your ten burgers, and decide to weigh them to see how close they are to your ideal 100 g burger. You're pretty good! 8 of your burgers are 100 g, one is 99, and one is 101. That's almost perfect. If you put them in a row, they all look exactly the same. Now, you give another kilo of hamburger to a six year old, and ask him to do the same. He makes 5 really big 191 g patties, and then realizes he's almost out of meat, so the next four are 10,10,10, and 5 grams. When he puts his in a row, you see 5 enormous patties, and 4 bitty ones, and one itty-bitty one. Obviously, these are two different ways of making burgers! But in each case, we have ten burgers, and in each case, the average weight is 100g. So they're the same! But they're clearly not the same. So how do we *describe* the difference, mathematically, between these two sets of burgers? That's what the Standard Deviation (SD) does for us. It tells us how far, on average, a member of a set (one of the burgers) is from the set's average (our \"ideal\" burger of 100 g). When the SD is small, as it was in the first case, you will see all the burger weights clustered around the middle (the SD was 0.5). When the SD is large, as in the six-year old's burgers, the weights will be all over the place (SD was 95). How do you measure this? Easy - you take the difference from each element (burger) from the middle (the ideal 100 g burger), add the differences together, and divide by the number of elements (burgers). That tells you how far, on average, any burger might be from 100 g. So, in our first case, we have eight burgers where \"burger weight-ideal weight = 0\", one where it's +1, and one where it's -1. These add up to ... zero! Does that make the SD zero as well? In fact, in any set, adding up the differences will always add to zero. The differences on the minus side always equal the differences on the positive side. Try a few sets and see. To get over this, mathematicians use a trick of \"squaring\" each measurement first, (because this way, all the negative numbers get turned into positive ones), adding them all together as positive numbers, and then taking the square root of the total. This lets us add together all the burgers that were too heavy, and all the ones that were too small, and find out what the average difference between any burger and the ideal burger will be.",
"If you flip the words around it makes a LOT more sense. Deviation (from the) standard. It tells you how much your dataset has a variation from the \"standard\" of said dataset. If you have 100 chickens, and 99 of them are yellow, and 1 is red, your \"average\" is \"yellow\", and your standard deviation is very very low, because only one chicken \"deviates\" (from the) \"standard\".",
"It's a measure of how tightly clumped your date is around the mean. If your data has low standard deviation then all your datapoints are tightly clumped around your mean. If your data has high standard deviation then your datapoints are very spread out, with the mean somewhere in the middle. Standard deviation is simply a commonly accepted way of measuring this spread. You calculate it as follows - take every datapoint and work out how far from the mean it is, the simplest way to do that is simply minus the mean from it which will give you the distance if the datapoint is bigger than the mean and minus the distance if the datapoint is smaller than the mean - square them all to make them all positive so they're easier to compare (don't worry we'll undo this later) - work out the average (ie the mean) of those answers - take the square root of that average (to undo the fact that you squared them all earlier) and that's your standard deviation",
"I'll try my best, with example similar to the top comment because it's probably the easiest to understand. I just want to add some things that may make it easier to understand. A is 5 years old and B is 30 years old. The average of the age of both A and B is (5 + 30)/2 = 17.5 C is 17 years old and D is 18 years old. The average of the age of both C and D is (17 + 18)/2 = 17.5 If you look at it, A and B, and C and D have the same average, but it doesn't really tell you much about their actual age. This is where standard deviation may help you. Standard deviation is basically the range between the average and the data you want to see (in this case, the age of A B C D). Standard deviation for C and D is 0.5. Where did 0.5 come from? 0.5 is the difference between the age of C or D and the average of C and D. I made a graph that could help: URL_1 The same is also applied to A and B. The standard deviation of A and B is 12.5, meaning that there is 12.5 difference between age A or B with the average of A and B. A graph that could help: URL_0",
"We have a good idea of what average (mean) means, so think of it like this: Standard deviation is the average difference from the average. It’s just a measure of spread. The higher the standard deviation, the more spread out the data is from the mean. If you look at the formula, it is the average of the square of the difference, which penalises large differences more.",
"With respect to the mean, it is how far you'd have to go lower or higher in order to comprise a percentage of all data. The idea is that the data lies in a bell curve around the mean. Suppose you produce random numbers between 0 and 20. After enough numbers, the mean should be roughly 10, and you could say confidently that 68.2% of all points lie between 3.18 (10 - standard deviation 6.82) and 16.82 (10 + standard deviation 6.82). It provides a way to get a sense of probability of where points will lie. And like the example of the random number generator, the more numbers added, the more precise that probability will be. If the range is from 0 to 40, you'd find that the standard deviation doubles, because it must to maintain the same percentage of 68.2%. It also tells you how rare am occurrence is of happening. Something beyond 3 standard deviations is likely to happen only 0.3% of the time in other words."
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mexskp | when someone dies peacefully in their sleep - what actually happens? is there a trigger to the death process? | Biology | explainlikeimfive | {
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"So it depends. Dying peacefully can describe a host of many issues. One example is that the person basically slips into a coma as parts of their brain start to shut down and then the brain looses so much function the heart stops and they die. This is what happened when my grandmother died. Took about 2 hours from when she lost consciousness. That said she started to get loopy maybe an hour before that. This behavior can be caused by hypoxia, pressure on the brain, malnutrition, poisoning, dehydration. You see why this question can get kinda complex.",
"Disclaimer: I'm not a human physician; I'm a veterinarian. There are three body systems that must function or immediate death will occur: * Cardiovascular system (heart and blood vessels) * Pulmonary system (lungs delivering oxygen to red blood cells) * Central nervous system (primarily the brain in this topic--although the brain can be injured and still sustain life) Sometimes these overlap, for example, when a person has a stroke--it's a problem within blood vessels (a blood clot) that goes to the brain and causes damage to the central nervous system. When one of these three body systems fail, death will follow quickly. Wear and tear happens on all body organs throughout life. A 25 year old typically has a stronger and healthier heart, vessels, lungs, and brain in contrast to an 85 year old. When an older person dies peacefully in their sleep, it's likely one of the body systems (or multiple) got disrupted and resulted in a quick death.",
"If someone dies peacefully they probably from their heart stopping from old age I am not 100%, but it is maybe related to you not being active",
"In most cases, when people are told someone \"dies peacefully in their sleep\", it's just to help them cope. Death is rarely ever painless. If someone has a heart attack while they're sleeping, they wake up feeling it before they die. If someone has an aneurysm they wake up feeling it. The vast majority of times people do not truly die peacefully in their sleep. It's super painful. But it doesn't hurt to tell someone who's grieving that the person was asleep and passed on never knowing better."
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mey9pb | if antidepressants don't contain calories, then how do they make you gain fat? | Seriously, I've been trying to lose weight for a year now and fat doesn't seem to want to burn off. Could this be a hormonal thing maybe? :/ | Chemistry | explainlikeimfive | {
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"The short answer is they mess with calories in, calories out. On the in side, they can mess with hormonal controls to make you hungrier, mess with neurochemicals to make you less satisfied with food, or even something as simple as making you sleep less so you have more time to eat. In better times they might let you go out and eat with friends, which is usually higher calorie than a home meal. On the out side, they might lower your energy levels (perversely) making you less likely to go out and exercise. Lots of levers, basically :( the only thing that worked for me was full on calorie counting, literally logging everything I ate and drank, to find out where I could cut stuff out.",
"I know my wife’s antidepressant causes increased appetite. I don’t know if that is a factor for you",
"Mostly they affect appetite. Remember though that almost all of the body's processes are controlled by hormones; any drug that changes your hormonal balance will have effects on your body, not just your mood.",
"They mess with serotonin, which helps to regulate appetite in addition to your mood. So they make your body think it's hungry when it normally wouldn't. Also if you're less depressed it can be easier to convince yourself to eat. You can try a different antidepressant. Different meds have different side effects.",
"See a lot of replies saying it only makes you hungrier or move less and hormones are nonsense etc. Now I'm no expert but don't antidepressants have direct side-effects of higher blood sugar, raised triglycerides and an effect on cholesterol and insulin? Sorry to question the calories in calories out hypothesis but I know model girls with type 1 diabetes who under-dose their insulin so they can eat what they want and not gain any weight. It seems to me that hormones, especially insulin, play a huge role in gaining weight. If they can literally eat what they want by manipulating their insulin levels because insulin decides if the body stores fat or not.. it definitely and massively effects weight gain. I also recall antidepressants lower testosterone which also would effect weight gain. And if testosterone is lowered that would mean cortisol is higher since they are \"hormone opposites\". Cortisol, the stress hormone, is famous for making it near impossible to lose weight. So if antidepressants effect your hormones.. I think they could for sure make you gain weight. Now if you eat more and sleep less that obviously makes you gain weight too.",
"A few reasons: They make you crave carbs, you then eat more. You are more active and the body requests more food but you eat the wrong food. Some SSRIs physically bloat you due to vasodilation. SSRIs mess with metabolism and fat storage."
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meyttz | How do contact lenses stay in correct position following your eye movement? | Technology | explainlikeimfive | {
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"Your eyes aren’t actually perfectly spherical. The cornea bulges out slightly, and the contact rests on that bulge, so as your eye moves, so does the contact",
"Contact lenses for astigmatism also have a nearly imperceptible weight on the bottom to ensure it spins to the bottom to line up correctly :)"
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mez3g6 | Why do you only fill a wine glass up 1/3? | Other | explainlikeimfive | {
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"Because part of the flavor experience in wine is from the aroma. That's why you'll see people swirl the wine around the glass too, it releases the scent. If you're just sipping from the top you're not smelling the wine as effectively as you do when you're breathing those trapped smells in the glass. At least that's how I've always understood it.",
"Red wine, yes you want to fill only partway up the glass. The design of the typical [red wine glass]( URL_2 ;) is bulbous in the middle to maximize the surface area of the wine exposed to the air when filled to that level, so more of the wine can oxidize and release its aroma. Then there is a lot more glass to trap the smell and allow room to stick your nose in, else if the goal was just to oxidise the wine but not capture the smell you'd be using a [coupe glass]( URL_1 ). White wine served in a typical [champagne flute]( URL_0 ) you want to fill near to the top, mainly just because its a smaller glass. The intent of the design here is the opposite, tall and narrow to minimize the wines exposure to the air, so the bubbles last longer which is not a concern with red wine."
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mez50b | Why is it that a movie plays at 24 FPS and is buttery smooth, but then a video game at the same frame rate is like a slideshow? | Technology | explainlikeimfive | {
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"- It is not buttery smooth. The choppiness of 24hz is quite obvious if you have ever seen movies at a higher frame rate. - Film cameras have natural motion blur, which kind of smooths movement across multiple frames. In video games this has to be created artificially. - Video games are interactive. The frame rate matters a lot more, because it has react to the player's inputs as quickly as possible.",
"Because videogames are interactive. You expect things to change instantly when you click something, and at 24fps there is a noticable delay between action and visible change.",
"i cant speak on video games but in film there is shutter speed, aperture, and frame rate. shutter speed is how long the shutter of the lens is open for aperture is how wide the shutter opens and frame rate is what you referred to. common frame rates are 24 frames per second, 30fps, or 60fps. with shutter speed, the longer the shutter is open for (meaning a slow shutter speed), the more action it picks up in each frame. it’s formatted to look like this: 1/1000 is a very fast shutter speed, while 1/30 is a much slower shutter speed. a typical rule of thumb for film is to double the frame rate (in this case 24fps) to get 1/48. not only are you picking up more the movement but each frame will likely have a slight blur in any motion, giving the illusion the frames blend together. for an action flick, cinematographer might choose a faster shutter speed to get a choppier appearance."
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mezbme | If higher cell turnover predicts increased cancer risk, why do children get cancer relatively rarely? | Biology | explainlikeimfive | {
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"Higher cell turnover contributes to cancer risk because the more times you have to copy the DNA, the more errors will stack up. Children haven’t had the time for all of those errors to accumulate because of how young they are"
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mezbw9 | - How do spiders create webs horizontally? | Other | explainlikeimfive | {
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"Wheel web spiders start their webs by just letting out a long thread and letting airflow move it around until it catches somewhere else. Then they traverse the line to span more lines as the basis of a web. You're talking about the wind but spider silk is so light that even a very light airflow or draft can carry it across. A house or a hedgerow still allows for plenty of airflow to move a 0.0003 mm thick line of silk. Spiders evolved this behaviour because flying insects essentially 'surf' flowing air. Building a web by letting the flow of air in a space dictate where the web ends up has a higher catch rate."
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mezf19 | How do anti wrinkle creams work? | Sorry if it’s been asked before but how do anti wrinkle creams work ? How does any application on the outside affect any cellular level changes? Thanks | Biology | explainlikeimfive | {
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"Anti wrinkle creams usualy contain hyaluronic acid. Hyaluronic acid traps water and as it is doing that it also adds volume to the epidermis (top layer of the skin). That leads to a real effect of wrinkles becoming more subtle. It really does not have any lasting effects, just temporary effect that is caused by drawing in water to the epidermis. best real way to prevent wrinkles from forming is using sunscreen and staying out of the sun."
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mf01yb | ...Walking on the moon... | I understand that the moon doesn't have an atmosphere and you wouldn't hear any sound...but is there an atmosphere in your spacesuit? Like the quietest room on the world do you hear your body? Blood rushing through your ears, etc. | Other | explainlikeimfive | {
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"No, you'd mostly hear the rush of coolant as the thermal control system in the suits tries to keep your body from boiling in the sun and freezing in the shade"
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mf0e1o | How do people spoof phone numbers and why won't/cant the phone companies close that security hole? | Other | explainlikeimfive | {
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"Because of the way the phone system was designed. If you have a multi line phone system and you're a business, you might have a need to change the outgoing number from certain extensions making outgoing calls so the caller appears to be calling from a specific number, like a main number for a business or queue. These digital phone lines give the business customer the ability to program their equipment to specify the outgoing number. Like sending email, you can put in anything as the sender. The phone systems don't have any way to know or validate if a number is owned by the person initiating the call. Keep in mind these are technologies that are several decades old. These digital lines aren't going anywhere for a long time, they are expensive, robust and heavily relied upon. And it's not easy to change the underlying phone signalling language used by phone systems across america that all route calls between each other. Like email, it's an old technology and still heavily relied upon. Things that prevent unauthorized emails and spam haven't changed the email \"language\" itself, but other technologies around it to help validate email and minimize the spread of junk mail The same solutions are needed (and to some extent) are already being implemented. But there is no silver bullet solution here because of the legitimate use cases, and because of internet systems that connect to the phone network, it's made it super easy for spammers anywhere in the world to remotely set up and launch spoofing campaigns by either hacking and exploiting a business's phone equipment or finding a shady fly by night internet voice provider. In order to effectively combat this solution, it would require extremely expensive upgrades for everyone from the smallest of independent telephone companies to the largest. There's progress being made, but it will be a long time before all the equipment is replaced. By then, who knows, we may have all but abandoned the 7-digit number we have in favor of something else. Edit: Clarity. Edit 2: Added a part about cost being a problem and why we don't have a solution.",
"Battling any kind of cyber security is like fighting a hydra - cut one head off, and two more appear. Or, more similarly, whack a mole. Your telco provider is likely working on fixing every issue they are aware of (unless its AT & T obv). The hackers just move on to the next exploit they can find and the cycle starts over again. Super ELI5: the teacher on the playground caught you playing with banned Pokemon cards. The teacher confiscates your cards, but you just go get more from the store and be more sneaky next time you play."
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mf0vpu | How does a fever work? | If you have a fever how is the best way to break it? I was told as a child to add layers to “break” the fever. But now I’m told that’s wrong. What is a fever and how does it work/stop? | Biology | explainlikeimfive | {
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"Imagine you and 5 friends are hanging out on your patio. It’s a beautiful day and your are all watching football on your outdoor TV. Then, out of nowhere, your neighbor Karen comes walking down the street, walks onto your property, and uninvitedly joins the party. She then flips over your bowl of tostitos and throws your salsa all over the patio. Karen is clearly messing up your party and making it less enjoyable. You need her to leave but telling karen to leave is not an option as she has made her place on your patio. So, you come up with a new idea, instead of asking karen to leave, you are gonna create a social environment so poor for Karen that she is going to have a hard time continuing to destroy your party. So, you change the channel and put on an old western w/ the volume cranked. Then, since you and your friends have just finished off a plate of hot dogs, you begin farting. You all keep farting, louder and louder, and you keep increasing the volume of the western. Karen, now in an environment that is not pleasing to her, leaves your patio, and you and your friends return to watching the game happily. In this example, Karen is a virus/bacteria and the farting and watching a loud western is a “fever”. A fever is a defense mechanism of your body. When a bad thing enters your body (virus, bacteria), your body, wanting to get rid of this invader, responds by heating up as it cannot simply ask the invader to leave. This creates an environment that makes it more difficult for that virus/bacteria to survive/reproduce. One method your body uses to heat up that everyones familiar with is “the chills”. Your body tricks your brain into thinking it’s cold and your brain instructs your body/muscles to shiver to create more heat to drive your body temperature up. Your fever permanently breaks when your body has fought off a significant amount of the foreign invader, as your body no longer needs to create an environment unfavorable for the invader and can return to its normal, optimal temperature for your essential body processes. Unfortunately, your normal bodily processes also suffer a bit when you have a fever b/c the body is no longer at an optimal temperature for those processes to run (you and your friends missed some of the football game and also didnt have much fun during the farting/western watching session). Adding layers will help insulate your body to drive your fever up (bringing karen and your friends inside and farting/watching a loud western in your secret room under the stairs), this might temporarily help you feel better as it can stop your chills but it does not break a fever."
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mf137l | What is nuclear fallout? How does the area of explosion get radioactive? | And how does a land burst yield more radiation than air burst? | Physics | explainlikeimfive | {
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"Fallout is basically dust that is left over from the explosion. In a nuclear explosion, the radioactive material is scattered around, both the original and the decayed material. This decayed material can still be radioactive by itself and is thus very harmful to most lifeforms.",
"When a nuclear detonation goes off, it splits a lot of atoms. When atoms are split, it releases a lot of energy but also makes a lot of \"half-atoms\" that are very unstable. These are called \"fission products.\" So the nuclear fireball is a hot ball of gas and heat, but it is also filled with these radioactive \"half-atoms.\" These are normally quite light, totally vaporized. But if they mix with heavier clumps of matter, like little pieces of dirt or steel or concrete, they will get stuck to them. The nuclear fireball rises and becomes the head of the famous mushroom cloud. It is then blown with the wind. If the fission products are stuck to heavier matter, they will then \"fall out\" of the cloud over time, creating areas of high radioactivity on the ground. If there isn't that much heavy matter in the cloud, they will stay light and not immediately leave the cloud. They will eventually come out, but it will be over a very long period of time, giving it plenty of time to disperse (and letting the fiercely radioactive bits decay themselves) and the amount of radioactivity any given part of the world gets will be very low. So this is why a surface burst creates more fallout than an airburst — the airburst keeps the fallout products light, a surface burst mixes them with heavier matter and makes them heavy."
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mf1jx5 | why can't we taste with our tongue when the nose is blocked | Biology | explainlikeimfive | {
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"You can still taste with your tongue, but the taste seems dulled because part of the experience of taste also includes smells picked up by your nose."
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mf1ksg | What does computer hacking actually look like? | Technology | explainlikeimfive | {
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"Either: a ) An email sent to someone working in the office with a dodgy link b ) A person opening a program and typing a few words in to a form before clicking \"scan\" c ) A very tired looking person looking over documents, slowly stepping over code on a black console on their screen, occasionally typing in a command or two before cursing a bit and trying something else. If said person is lucky maybe they get a somewhat positive response from their commands and they get slightly less irritated. Hacking is exceptionally boring as a spectator activity. It's not fast and frantic with numbers flying all over the screen and the need for three people using two keyboards. It's just a person writing code and sending commands in hopes of finding and exploiting some weakness.",
"It can still involve a screen that is full of incomprehensible code (to an outside observer) but it will also involve browsing documentation of other software standards and implementations, looking at and copying code from other programmers, sitting around and pondering problems, etc. It isn’t some intense keyboard sprint, hacking usually takes weeks or months to perform.",
"The vast majority of what is called hacking these days mainly refers to social engineering like phishing. Actual hacking usually consists of building a program to do something for you followed by looking for a way to get a target to execute that program. It’s mainly software development which is essentially text editing interspersed with cursing and long sighs.",
"Mostly casual typing, maybe a bit more stressed hair pulling dependent on the hacker. If you are a professional penetration-tester (good guy hacker) then it's this followed by hours of report writing, so even more casual typing.",
"Most of it is done via phishing, email attachments, social engineering or using leaked passwords (when people have re-used the same password on other sites that have been hacked in the past). The next way in is unpatched software. If a company hasn't updated their mail server or some other piece of software since 2018, there's a good chance that there are well-documented vulnerabilities, so you'd read up on them and spend a day or two or three putting together a script that takes advantage of this vulnerability. And if that doesn't work, you look at what kind of software is running on the server and look for some kind of service or app or device that's accessible from the internet and somewhat obscure. You do that because the most commonly used software tends to be pretty well maintained and probably doesn't have have undiscovered, easily exploitable bugs. But some kind of niche device or app that hasn't been scrutinized to the same extent is probably not as bug-free. Then you get yourself a copy of the app or device and try various techniques to get in. And once you find a bug after days of testing and probing, you may be able to use the same technique on the network that you're trying to break into. So it's basically someone sitting in front of a computer for days or weeks, bored, slowly going over hundreds or thousands of pages of decompiled code or memory dumps as well as writing code. It's about as exciting as an accountant doing an annual report in Excel, so it wouldn't really work in a movie."
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mf2njx | why do people's elbows not hurt when pinched, but do hurt if cut or scraped? | I noticed that if I pinch my elbow it doesn't hurt or anything and I can barely feel it. However, I also scraped my elbow on the corner of the wall while passing it quickly and that sucker hurts like hell. What's the reason for this? | Biology | explainlikeimfive | {
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"The elbow skin has lower nerve content so you small stimuli like punching are not enough to cause pain. For that you need a bigger stimulus like the skin being damaged when you scrape it for example. For more detail, there are different types of nerve endings and sensors, the proportions of these different types of sensors can also vary in different parts of the body leading to different sensation patterns."
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mf33rv | What are leaves made of? | My 3 year old just asked me “what are leaves made of” and I don’t know how to answer that. What do? | Biology | explainlikeimfive | {
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"They are made out of cells like our bodies are. The difference is that their cells contain cellulose which gives them rigidity and strength, and chlorophyll which is how they make sunshine into food (and why they are green). Water also makes up a fair bit of all cells, ours or plants. This is why people and plants need water. I know this sounds simplistic but I’m trying to think in terms of 3-5 year olds. If you want to, search out microscopic pics of plant cells online, they are often quite pretty and kiddo might find it cool.",
"This is a tough one, since it requires explanation of what everything is made of... I'll do my best... Every living thing is made up of little structures called cells. Each cell is like a tiny factory responsible for doing different things. Some make food for other factories, some help keep the others safe from danger, etc. Leaves are made up of a bunch of those little factories, that are responsible for turning sunlight, air, and water into food for the plant, sandwiched between a couple layers of factories that keep the inside factories safe, just like our skin keeps us safe."
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mf3ele | What happens to glitters/spray paint I inhaled over time? | Do they stay in my lungs forever or does the body have some kind of process to cleanse the lungs? | Biology | explainlikeimfive | {
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"The air tubes leading down and to each lung are coated with mucus, similar to the snot in your nose. The inside lining of the tubes also have cells with cilia, tiny hair-like protrusions that move in a wave to help push the mucus upwards and out of the respiratory tract. Anything stuck to the mucus will either end up going into the stomach or coughed out. However, any particles that get beyond these tubes into your lungs will be stuck. Your body detects any foreign substances and puts a fiber shell around it to isolate it. Even a healthy, non-smoker lung will have visible particles from a lifetime of breathing. Breathing in too many particles or chemicals will eventually impact lung function. Certain particles also can carry bacteria, fungi, or viruses which can infect the lung, causing pneumonia. Lastly, certain substances like asbestos and silica are especially spiky and cannot be fully isolated. They constantly cause damage in the lungs that need fixing. The body's response and fixing of the damage increases the chances of lung cancer."
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mf3sx3 | Is there a specific reason why being "put on the spot" or under pressure, that makes it seemingly hard to think? | A good example would be when you're having a conversation and someone asks what kind of music you like, and even if you've recently been really enjoying something, you can't think of literally any artist ever. | Biology | explainlikeimfive | {
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"Most of the thinking we do is actually passive. Ever had a logic problem, or a maths task, or other similar problem that you need to think to solve. Then you go do something totally different and don't think about the problem at all and suddenly you realise the solution? This is because you kept thinking about it, unconsciously. Lot of our \"processing power\" is reserved by the \"operating system\" to handle background tasks. The portion of \"thinking power\" we are able to consciously access is very limited. This is actually really great solution. Imagine having to consciously process everything you do all the time. Now this kind of processing of information, passively in the background isn't that fast really. Now when you are put on the spot, you don't actually want to start slowly processing things, you want to access quickly the learned behaviours and responses you have, along with your instinct. The thing with these \"Name a thing quickly\" or such is that, you have never had to practice naming something quickly on the spot. But if you want to be prepared for it, you can practice this response. But we are actually really good at doing things under pressure. This is why we run drills of important things. If a fire alarm goes off, you probably know how to leave the building, call the emergency services. A EMT, doctor, or a surgeon knows how to response in an emergency situation. How to do quick diagnostics, how to stabilise a patient. This is doing things on the spot. They are using behaviours and responses that they have practices for situations like this. Imagine when you are driving a car, and something sudden happens front of you. What do you do? Do you stop to logically analyse what happened front of you and consider how you should respond? Or do you slam the breaks to slow down and try to steer towards the safer side of the event? That is reacting under pressure right on the spot. If you'd ask and experienced EMT, what to do when the patient gets a sudden seizure. They might not be actually able to say what they would do right away, but if put on the spot they know exactly what they should do. This is because they have learned to do these things under pressure, so having them do it outside this environment is mentally harder because they haven't practised how to do it. They can do it, but it takes more mental effort than under pressure. So if you want to be able to name your favourite musician on the spot under pressure, you got to practice naming your favourite musician on the spot under pressure.",
"put on the spot and put under pressure are 2 different things 1. put under pressure activates a fight or flight response, your brain is occupied in this situation with getting out and not with giving an answer 2. put on the spot has many conotations: depends if you feel threatend by the speaker (how your brain percieves the way the question is being asked), if you would like to impress him/her, if you have too many options (you like a lot of styles of music), if you're annoyed by the person (you than look for a generic answer ending the conversation), the world around you (maybe your brain is concentrating on something else). All these and many other factors play a role in the activity of your brain at that time. And sometimes it's too much to compute, several areas of your brain compete to give the final answer.... which doesn't come",
"Because you’re given little time to think and respond to the “threat” at hand - it’s the same principle as being jump-scared or being surprised"
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mf40do | Why do we give so much credit to the directors of films/tv shows, but hardly any to the writers? | Other | explainlikeimfive | {
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"To be fair, awards shows like the Emmys, Golden Globes, and the Oscars all recognize writing, it's just not as public facing as directing. As others have said, it's the director's vision that brings the script to life. I'd also argue that along with receiving most of the credit for a good film, the director tends to get most of the blame for a bad film."
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mf42ia | Is there a simple explanation of gravity? | I often hear that gravity is not a force, but simply the curvature of spacetime. A common example given is having a heavy ball placed on a rubber sheet. The ball sinks, distorting the sheet. Therefore, other "orbiting" objects will also tend to roll towards the sunken part. What I can't understand is, what causes the objects to "fall" anyway? On earth, that's just the planet's gravity. If you did the same experiment on space the objects wouldn't roll down. So how is this an explanation of gravity as a curvature, when it requires a *force* to work? Is there a better explanation? Am I just missing something? | Physics | explainlikeimfive | {
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"The rubber sheet analogy is somewhat useful but not super accurate because, as you said, it only makes sense in the presence of gravity. Think of it this way. All things in the universe travel in a straight line, unless acted upon by an outside force. This makes sense but then how do you explain the orbits of planets, right? They certainly seem to be going around in circles and not in a straight line. The explanation is that they ARE going in a straight line, but spacetime itself is curved. The objects in the gravity well are following a geodesic. So, the straight line ends up curving when the spacetime it's moving through is curved by gravity.",
"The simplest explanation of gravity is that it IS a force of attraction between two objects with mass. This explanation is pretty much good enough for anything other than things moving at very high speeds, very long distances, very small particles, and for massive objects like stars. Any other explanation is not so easy without resorting to reasonably advanced mathematical models."
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mf4s3k | Why are there so many conspiracies about 5G in particular, but not for preexisting cellphone networks? | Technology | explainlikeimfive | {
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"Basically all new techs have some kind of conspiracy nutters (I’ve still got a non-gmo, anti-microwave aunt). Same thing happened with cell phones, and WiFi, and every tech that can’t be seen. The only reason the 5G conspiracy is more common is that a significant portion of the US has recently taken a departure from reality. The formerly tiny corner of the internet that substitutes is own reality went from a fringe to now a significant portion. That means that more people with low passive critical thinking abilities are seeing hubbub about something they don’t understand...and only see the conspiracies instead of the scientists saying “it’s just non-visible light”.",
"Side note to what everyone else is saying: a conspiracy and a conspiracy theory are different things. A conspiracy is an actual crime with a legal definition where multiple people are orchestrating a crime. A conspiracy theory is a term that's almost always a in reference to a crack pot taking circumstantial evidence (or none at all) and saying it's proof of an actual conspiracy.",
"Lots of 5G talking points are about a 'HUGE INCREASE IN BANDWIDTH' or the 'ABILITY TO CONNECT 100x MORE DEVICES', which can come off as increasing exposure to more powerful radiofrequencies. In reality, 5G wavelengths are less penetrative and MUCH more narrow (power spread over less than 1 degree vs. LTE 10+ degrees) but I don't think people with strong negative opinion on the technology understand it very well.",
"Unscientific answer: There WAS 4g conspiracies also, same with 3g, etc. It's just so long ago that nobody remembers. Also, I imagine that the social media age made this one a lot more widespread.",
"People can be made afraid of things they don’t understand. Existing cell phone networks generally aren’t something people fear because they have been around for a while and apparently haven’t been causing harm. You can’t argue a cell tower that has been standing for ten years is going to turn someone’s brain to jelly, because why hasn’t it already? But people might believe new technology they have never encountered can cause such harm."
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mf5aku | What goes on in your head/body when you drink alcohol? | Like how do you get drunk from alcohol? | Biology | explainlikeimfive | {
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"Perhaps surprisingly, we don't fully know yet. So, for starters, alcohol is specifically a molecule called ethanol. When you drink this ethanol, it goes into your blood and from there circulates through your body. Ethanol is poisonous at high levels, so to prevent it accumulating, cells have evolved a way of turning it into something harmless, which is a three-step process. The first step of this process converts ethanol into another molecule called acetaldehyde. Acetaldehyde is actually more poisonous than ethanol, but it's a necessary first step in the process. The second step converts acetaldehyde into a molecule called acetate, which is a lot less poisonous. Finally, acetate is converted into something called acetyl co-enzyme A which is an energy-dense molecule that cells can use to generate energy in a similar way to carbohydrates. This end product is the reason alcohol has calories. It is not yet entirely clear how ethanol and its later products affect the body. They don't have any measurable effect until there's loads of them, so it's hard to study like we might other drugs (as this method requires using very small amounts and seeing how cells change in response). What we do know is that ethanol and/or acetaldehyde have some kind of effect on a lot of different things in the brain called neurotransmitters. The brain works by having lots of different brain cells \"talk\" to each other. They do this at positions between cells called synapses, where electrical signals in the input cells are converted into chemical signals, and those chemical signals produce a new electrical signal in the output cells. At any given synapse, there are almost always multiple input cells. Each input cell sends its own signal to the output cell, and the output cell must figure out whether or not it should create its own signal to send to the next cell in the line. It does this by basically adding up the \"values\" of the input cell signals: some input cells say \"Do it!\" and some input cells say \"Don't do it!\". Each of these signals has a strength associated with it, so you might have one cell creating a weak \"do it\" signal and another creating a very strong \"don't do it\" signal, which can be imagined as \"do it\" signals being some size of positive value, like +5, and \"don't do it\" signals being some size of negative value, like -5. The output cell adds all those numbers up, and if the total is higher than a certain threshold (say, 30), it will continue the signal. If the total is lower, it'll do nothing and the signal will stop. What ethanol and/or acetaldehyde do is they stick to the bits of the output cell that detect the input signals, and trick them into thinking certain signals are stronger or weaker than they really are. This happens mostly to a sensor called GABA, which detects \"don't do it\" signals. If normally the input \"don't do it\" signal was -5, then when drunk, the output cell would perceive that signal as a -10 instead. This makes the output cell less likely to continue the signal than it would be normally. Essentially, a lot of the brain's functions work less well because it's harder for them to get a signal down a full chain of brain cells - all brain cells have some cells saying \"don't do it\" to them, but alcohol is like giving those \"don't do it\" cells megaphones, so the \"do it\" cells have to shout even louder to make themselves heard. This is where a lot of the perceptions of drunkenness come from, like the sudden inability to do basic things. The other major effect that ethanol and/or acetaldehyde has in the brain is on the dopamine neurotransmitter, which you may have heard of as something like the happy chemical or the reward chemical or something. This is a neurotransmitter used in the parts of the brain that control reward-motivated behaviour - the more something stimulates these parts of the brain, the more we'll want to keep doing it. Addictions tend to act upon this part of the brain, making it so effective that we start to become dependent on it just to feel normal. In these circuits, once dopamine (a \"do it\" signal) has been released, the input cell that sent the dopamine sucks it back up for reuse. Ethanol/acetaldehyde block the sucking up process, which means the dopamine remains between the cells for longer, which the output cells perceive as being a bigger and longer-lasting \"do it\" signal - this makes it more likely for them to continue the signal down the chain. There is also evidence that ethanol/acetaldehyde affect a wide range of other neurotransmitters in the brain, but it's not clear how relevant those effects are to the experience of alcohol. Finally, a hangover occurs after the body has converted most of the ethanol into acetaldehyde. Basically, when the alcohol is mostly in the body as ethanol with a bit of acetaldehyde, that's being drunk. When it's mostly acetaldehyde and acetate, that's being hungover."
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mf703b | How does our stomach seperate stomach acid from other fluids we drink and controls what gets into our bladder? | I've wondered about that today. I found no answer to how that's possible, can someone please explain how our stomach achieves that? | Biology | explainlikeimfive | {
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"It doesn't, really. Everything from the stomach enters the intestines, and there the stomach acid is neutralised by the addition of bicarbonate produced by the pancreas. That reaction produces carbon dioxide, salt, and water, all of which your intestine is fine to absorb.",
"Also, the bladder does not receive liquid from the stomach (or digestive system) The bladder is filled from the kidneys, which filter your blood stream",
"TLDR: Your stomach and bladder aren’t directly connected. As you pointed out, your stomach makes lots of acid and chemicals to help break down food. The broken down food + acid then head to your intestines. To protect your intestines, your body makes a basic liquid called bile. Acids and bases “cancel out”, leaving only the broken up bits of food. These bits are really tiny, so tiny that the cells of your intestine are able to take the useful bits and absorb them into your body (sometimes into the blood). The not-useful bits continue to go travel through your intestines until you poop them out. Your bladder is connected to your kidneys. Your kidneys take blood and pass it through a tiny net. Only REALLY tiny stuff gets through. Blood cells and big chemicals won’t get through, and will stay in the blood. The tiny stuff flows through your kidney tubes. Just like in the intestines, the kidney cells take ‘useful bits’ back into the blood. Some of your kidney cells do the reverse - they put things in your blood that your body doesn’t want into your kidney tubes. The kidney tubes connect to your bladder and you pee it out. Sort of related- you have two types of special cells in your kidney. One likes acid- it puts base in your kidney tubes to get rid of it, and puts acid back in your blood. The other does the reverse. These cells work together to make sure you don’t have too much acid or base in your body",
"[Ion pumps]( URL_0 ) more create and destroy acidity rather than separate it. Like a slightly leaky boat with a pump: as long as the pump is powered, the boat stays dry and afloat. Your stomach stays acidic, and your blood alkaline."
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mf7wje | Why do we get the the weird 'someone is watching us' vibe when someone stares at us even from behind? How do we understand that someone is staring at us, even kf they do it from behind us? | Biology | explainlikeimfive | {
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"Many studies into this have been done. It turns out that the situation does not actually exist. The chance someone would figure out if they were being watched or not was the same as if they'd done a coin flip to decide. What actually happens is we remember events where something significant happened way more easily than events where nothing did. All those times you might've thought you were being watched, only for there to be no one? You forget about those because they weren't important. But any time you actually were being watched, you remember. So you end up with a bias that makes it seem like you're more correct about this stuff than you are.",
"If you turn behind you and find someone staring at you, it is probable that they were not staring at you, but instead turned to look at you because you moved suddenly. Do that enough times and you start to feel like someone might be staring at you at any given time."
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mf7zg6 | Can you guys dumb down the second amendment | Other | explainlikeimfive | {
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"The 2nd amendment says \"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.\". What does that mean? Everyone has a different opinion. Can everyone have guns? Maybe. Can only organized military groups have guns? Maybe. That's why wording is important when it comes to laws. You don't want it to be open to wide interpretation. Unfortunately the 2nd amendment is open to a lot of interpretation. No one is \"right\" or \"wrong\". That's just how legal issues work. It's up the legal system to decide how to interpret things.",
"America had just had a war and couldn't afford a large standing army to defend what was a large area of land fairly sparsely populated with people. So in order to be able to defend the territory the government didn't want there to be anything stopping people from owning muskets and other guns, so that in times of trouble all the able-bodied people could be formed into an armed militia to defend their local area to delay any invaders until the regular army turned up. URL_0",
"If you want to strip it down to its barest essence, look at the last bit. > The right of the people to keep and bear arms shall not be infringed. This simply means that the Constitution *recognizes* (but ***does not grant***, i.e. is not the source of) the inherent, natural right that \"the people\" have to possess and carry firearms. The colonies had just waged and won a war for their own independence, and were wary of the power of government (specifically the federal government) over the State and the individual citizen. Enshrining the right of the people to keep and bear arms was seen as an essential check on that power."
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mf880u | How were codes for Game Genie/Gameshark/Action Replay found/created back in the day? | Technology | explainlikeimfive | {
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"The other answer is talking about something different, actual cheat codes. Most game genie devices that I'm aware of don't do that. They alter memory addresses. The console stores everything in memory. Ammo, weapon, lives, points. The game genie forces the value to whatever it wants. As for how it's found (I e. How to make the code), trial and error. You can take a dump of everything currently in memory. It will be in hex, it won't be in English and won't make sense to a naked eye. Then lose a life and take another dump. Compare what has changed. Even if it doesn't make sense reading on its own, your can still spot the difference Do it enough and maybe you learn that line 4, character 6 is where the life value is stored. The \"code\" can then be made as an instruction of what location in memory to edit and what value to insert.",
"These devices could look at all of the numbers stored in the memory of the console. To make a cheat work, you would have to find a memory value that matters (like the player's HP or number of lives or whatever) and tell the Game Genie what value you want it to have. To make it more clear, let's look at an example card for Final Fantasy IX using the GameShark. Here's the code: 8008B7B0 FFFF The first portion \"8008B7B0\" is the memory address that the GameShark is modifying. Like 1234 Sycamore St. is the address where Steve Smith lives. For this code it's the place where the amount of money the player has is stored. The second portion \"FFFF\" is just the largest number that can be stuck in that memory address. It's hexadecimal for 65,535. So the GameShark in this case is forcing the player's money to always be 65,535 by screwing with the console's memory. So how is this code found? By checking all the different numbers in the different memory addresses in the console until you found the address you want. A lot of these devices could do this on the fly. Many GameShark models had a little button that you pushed and it would pause the game and do this. So it pauses the game, then you tell it to search for a number. If I'm looking for player money in FFIX and I had 125 at that point in the game, I could punch in 125. Then it tells you all the different memory addresses that currently have that value. To narrow it down, you could earn or spend a little money and do the process again until you keep getting the same memory address show up in your search results repeatedly. That's your new cheat code: 8008B7B0 for the memory address and then whatever number after that that you want."
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mf9giz | Why do the Kardashian’s children still look so much like their parents, even though they had numerous amounts of plastic surgery done? | Other | explainlikeimfive | {
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"Cuz they all use the same plastic surgeon?"
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mf9mzp | Why is it typically windy during the day but not so much at night? | Earth Science | explainlikeimfive | {
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"The sun heats up the air, which causes density differences, which causes sinking and falling air. Then you get wind.",
"Must be a local thing where you are, possibly because you are a long way from the sea, here in Ireland it is now gone ten PM and where I am the wind is blowing a hooley.",
"Because of the sun: it warms the earth up so there is a difference in temperature: cool air (more dense than warm air) at ground level, warm air (less dense than cold air) higher up. And that triggers air moving.",
"During the day when it’s warm. The warm air will rise up into the atmosphere. This leaves behind an area of lower air pressure on the ground, and air will move to equalise that pressure. Sort of like when you have high pressure air inside of a balloon and you let go of the tip. The air rushes out of the balloon to equalise the pressure inside and outside of it."
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mf9svt | How do new movie/tv shows find cast members if it’s a secret project? | Other | explainlikeimfive | {
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"They interview people for an unnamed/undescribed project. If they decide they might hire any of those people, they have them sign NDAs, before proceeding. Any actor knows that if he breaks the NDA, he's probably not going to work again, so they tend to keep the project a secret.",
"back in the '70's I knew some folks got work on a \"horror\" movie being filmed in Oregon called \"Harvest Moon\" i think the title was. The actors couldn't breathe in their costumes so it was their job as soon as 'cut' was called they ran over and pulled the heads off so the actors could breathe. They didn't know the creatures were \"Ewoks\" until the movie came out.",
"Assuming they don’t already know who they want and have access into getting them. One can simply cast with a fake title, maybe change the name of the character Temporarily. Once the cast is set they can know what the actual project is and sign an NDA to not speak about it.",
"First, most productions have a \"working name\" that is usually totally unrelated to the intended release name. Aside from the main stars, none of those auditioning will know what the final movie will be called. It's quite common for them to not know who will be directing it or producing it either. Second, big productions will use casting agencies for most or all of the secondary roles. That agency will be given a brief thumbnail description of what the directors and producers are looking for. That agency then does the heavy lifting part of holding large auditions or sorting through talent agency submissions to come up with a short list of candidates. Third, that short list of candidates may then go through a second round of auditions with the director, producer and perhaps senior writer(s). This is often the first time the candidates get a solid idea of who is being the project. Being required to sign a non-disclosure agreement at this stage is extremely common. Fourth, it's hard to nail down just how common this is, but any of the secondary cast who leaks stuff to the media can easily find themselves blacklisted, even if they aren't already bound by an NDA. Even if talent agencies, casting agencies and main production staff don't engage in blacklisting, would an up and coming hopeful want to risk it? The industry often has to re-shoot scenes anyway. Having to re-shoot scenes that don't feature the main cast because you had to replace a secondary character half way through production is not a big deal. So even during production, if you screw up badly enough, you can be replaced quite easily. The brutal reality is that the movie industry sees thousands of young hopefuls for every role. Competition is fierce but usually anonymous. You don't know who else may have auditioned for a role you want. You don't know who you're going to be ultimately working for or how your desired role will fit into the over all story. It is an extreme example of a buyers market. (and that power imbalance is why the \"casting couch problem\" continues to thrive.)"
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mf9v0v | why Anatomy and Physiology is so complicated and categorical? | Biology | explainlikeimfive | {
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"text": [
"For medical reasons, and also for obvious purposes. The obliques are two distinct sets of muscles, not different kinds of the same middle."
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mfa1w6 | How do they know a person had a heart attack after the fact? | Biology | explainlikeimfive | {
"a_id": [
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"text": [
"Because there is an enzyme that is present in the blood that only appears after a heart attack."
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mfaslq | Why is Vacuum heavier than H² ? | Physics | explainlikeimfive | {
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"A lighter-than-air vehicle that uses a vacuum instead of a low-density gas would, in theory, work. The idea is known as a [vacuum airship.]( URL_0 )The lifting force a lighter-than-air ship can produce is based in the differences in pressure between the atmosphere and the lifting gas. A vacuum has a pressure of 0, which means the difference and thus the buoyancy would be at its absolute maximum. The problem is that the pressure difference between sea level and a pure vacuum is absolutely *massive*, far more than sea level and a helium/hydrogen balloon. It would be so large, that you would need an incredibly strong container to stop it collapsing in on itself. And a very strong container is a very heavy container, which would counteract the buoyancy of the vacuum and make it drop like a stone. Practically, it's better to use low-density gasses, because while they produce less buoyancy, they can also be housed in thinner, lighter containers that ultimately make them better at lifting things.",
"A vacuum itself isn't heavier than h2. Unlike h2, however, it does not provide pressure to ints container. This means that a container in air will be crushed without strong supports. Instead of a thin sac, you have a giant steel pressure vessel - ten thousand times as heavy for a few percent lighter contents.",
"If others told you that, they're wrong. That said, a vaccuum \"air\"ship would require you to hold up its sides against atmospheric pressure, while a helium balloon does not (because even at atmospheric pressure, helium is less dense than air).",
"Those people are wrong. The end. Well they're sort of wrong. If you consider the buoyancy of a volume of H2 vs that same volume of vacuum, the vacuum wins because it weighs 0g/L while H2 weighs 0.0771 g/L compared to air's 1.2g/L. (The buoyant force is air-lifting gas density) Complications set in once we try and figure out ways to create those volumes. H2 is a gas that I can use to fill a light and thin bag to match atmospheric pressure, and then attach the bag to whatever I want to lift. The vacuum on the other hand, needs a structure that can support itself against the pressure of the atmosphere which is substantial. Each square meter needs to hold back a force equivalent to the weight of 10 cars (or one car per square foot if you prefer Freedom Units). That structure will almost certainly weigh more than 0.071g/L and make the vacuum lifter less efficient than a similar size bag of hydrogen or helium. EDIT: Typoed hydrogen density.",
"They are incorrect. However, there is no known material that is rigid enough to maintain its shape under vacuum while also being light enough that the container (despite being filled with nothing) is lighter than air. You can fill a latex balloon with hydrogen or helium and it will be less dense than the surrounding air and be lifted as a result. If you remove all of the air from the balloon, it will deflate, and its density will be greater than air. On the other hand you can create a vacuum in a steel container, but because of the weight of the steel, it will be denser than air. And if you try and create a steel container with very thin sides and a large volume of empty space inside, it will not be able to withstand the pressure and will collapse in on itself, much like a deflated balloon. Hypothetically, there is no reason why such a material could not exist, and it is possible that we will one day find one. This would be very useful because we could create \"vacuum balloons\" that could operate like zeppelins and carry large amounts of cargo through the air expending very little energy."
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mfbpt6 | How are DVD "easter eggs" created? | Technology | explainlikeimfive | {
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"The DVD menu system is more complex than it seems. You can make buttons/links pretty much anywhere, make links only available at certain times, and act on simple variables. Most easter eggs are presented by abusing these features to hide a piece of video until someone finds the button and presses it."
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mfbrcm | Religion vs Mythology | Other | explainlikeimfive | {
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"Religions are a way of life, following a set of rules or philosophies. Mythologies are simply stories about the past, or fables about the origins of the present condition. Now, these often go hand in hand, as religions like to use myths to set the context for their rules and philosophies, but they are not the same thing. I should expand on this by saying that the reason people confuse the two is because in modern Christianity simply choosing to believe in the truth of the mythologies is basically the only prerequisite for being part of the religion, so the mythology is almost indistinguishable from the religion. If you accept the mythology, you accept the religion. This is not strictly true, but is the common popular sensibility in the modern US. But, beyond modern Christianity, looking at religions in general, you can certainly choose to follow a set of philosophies or sets of rules, regardless of whether there are any mythologies behind them."
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mfbwkl | What determines if a fuel is explosive or not? | So specifically I'm interested in gas vs diesel, but I would love to learn further about the specific property that determines this. It's obvious that an explosion occurs when pressure builds up, and when gas ignites, it propels outwards and expands, but why isn't diesel like that? Why isn't every flammable gas explosive in nature? | Chemistry | explainlikeimfive | {
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"All fuels are potentially explosive if you put enough vapor in a small enough chamber. The question is whether the vapors are warm enough to ignite. Gasoline has a flash point of -40C/-40F. This means as long as gasoline is above -40C/-40F it'll ignite if you have an ignition source. Hell, if you have gasoline vapors and an ignition source in close proximity you can probably get it going by accident. Diesel on the the other hand has a flash point of > 52C/125F. This means diesel vapors won't ignite until they're over that temperature. Try lighting a cup of room temperature diesel with a lighter. It won't work. In the case of an engine this temperature requirement is easily met by the cylinder itself which is why diesel is still capable of being used in an engine. In open air? You won't get temperatures that high so trying to ignite the vapors won't actually work. Gasoline? It's heavier than air and probably above its flash point so it'll pool around the floor and then ignite if you even look at it funny."
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mfc964 | What is the statistical importance of "median" and "mode?" | Inspired by a question about standard dev, this one is a question that has been bugging me for years. I've been using the mean and stdev a lot in my work and during my college years, but I never really used median and mode outside when it was introduced. I've seen no use for it so far. So, ELI5? especially to those people who use this frequently. | Mathematics | explainlikeimfive | {
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"Median is good for excluding the extreme elements. Consider the difference between the mean income of a nation and the median income. The mean income is enormously skewed by the Gates and Bezos of the world who have extreme wealth. In contrast, the median wealth gives us a far better appreciation of what we really want to know: how much money a 'normal' person makes. Mode is generally only used with discrete sets, so it doesn't really fit the same sort of problems that mean/median do. An example would be a multiple choice quiz you administer to your class. The right answer is C, but the mode answer is B. This allows you to identify a common misunderstanding about your class."
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mfcdci | How does the shell of turtles/shelled animals connect to the rest of their body? I know it's part of their skeleton but is it covered in skin? Where does the turtles flesh end? | Biology | explainlikeimfive | {
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"The shell is an outgrowth of the skeleton. The upper shell is part of the spine, ribs and pelvis. This is what the inside look like. It is covered with something that may have been reptile scales 200 million years ago. URL_0",
"The topside of the shell is essentially skin. The shell itself is made up of ribs that widened and fused."
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mfdbsl | Does having a roll of quarters in your fist actually ever help in a fight? Is it just a myth or is there a biomechanical advantage? | Physics | explainlikeimfive | {
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"Mechanically, it actually will help because it means your fist is less \"squishy,\" and as a result there's more of a direct connection between your fist and your wrist.",
"Yes, it helps. By adding more weight to your fist your punch hits harder. Two things matter when determining the force of an impact, speed and mass. You can swing as fast with a roll in your fist as you can without, and the mass is increased dramatically. Source: hung out with a bunch of sharps back in the day and this one little kid swore by the quarters. Cops cant call it a weapon, you just need bus money. And a roll of quarters weighs the same as standard MMA gloves. Not too heavy to slow your swing but heavy enough to matter. Dont know what all these people are talking about your knuckles for - the idea isnt to protect your hands it's to cause maximum damage to whoever is hassling you with a single punch.",
"It is more to make your fist land solid. The roll of quarters doesn't actually do much; technique does more. That said, you don't need to hit somebody hard to knock them out, you just have to hit them square and that's surprisingly hard to do. That's why boxers spend so much time training technique.",
"A proper punch requires you line up your two big knuckles with the bones in your firearm. This usually means your knuckles are pointed slightly below your wrist. Your fingers must be curled in and thumb underneath the make your hand as solid as possible AND keep your smaller knuckles out of the way from the striking knuckles (the ones lined up with your arm.) A roll of quarters is going to make a proper fist impossible but give you slightly more momentum. If you hit something hard like a skull your fingers are going to get hurt bad. Maybe for soft flesh like a kidney or gut shot the coins might give someone who doesn't know how to hit a slight advantage but it's not going to be better than learning how to make a proper fist and throw a proper punch. If you want a punching weapon get some knuckles. Or spend the money on deescalation techniques and never have to punch anyone.",
"FINALLY someone has asked this important question. Yes, having a roll of quarters in your fist helps in a fight. Imagine the utility. You could pay surrounding spectators to assist you in the fight OR you could pay off the aggressor! Lastly, if there are no spectators and bargaining with your adversary has failed, you could simply chuck them at the enemy. So yes, they are highly advantageous in a fight."
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mfdezp | If you turn a cup filled with water with a few pieces of ice, the ice does not appear to move. Why? | Physics | explainlikeimfive | {
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"Objects at rest remain at rest, unless acted on by an external force. If the spinning glass isn't touching the ice, the only way for it to transmit force to the ice is to first spin up the water. Since the glass is usually circular, the water is not forced to deform as the glass spins, and the only interaction is the slight friction between the water and the glass' walls—essentially a simple [fluid bearing]( URL_0 ). With very little friction between the glass and the ice, it takes a lot of glass-spinning to get the ice moving noticeably.",
"One feature that makes liquids liquid is that they can only achieve a certain amount of shear force. What this means is that one section of liquid can slide over the adjacent section pretty easily. Imagine your glass of water being split up into thin concentric cylindrical sections. The section on the outside is touching the walls of the glass and so experiences some shear force from the rotation of those walls. It passes a bit of that force to the next layer in, and so on. Each layer experiences less force, but they all experience lots of resistance to movement because water is heavy and heavy things don’t like to change direction or speed; the water started stationary and wants to stay that way. So quite rapidly as you move from the wall into the bulk of the liquid you find that it barely moves at all, and so the ice floating in the water doesn’t move either."
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mfdq8s | What does 'orthogonal' mean in a statistics context? | I have tried many times to understand this and thus far failed every time. What does it mean to say that data is orthogonal? Can you provide an example of data that would be orthogonal versus data that would not be orthogonal? | Mathematics | explainlikeimfive | {
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"Simply put, orthogonality means “uncorrelated.” An orthogonal model means that all independent variables in that model are uncorrelated. If one or more independent variables are correlated, then that model is non-orthogonal.",
"I like to remember it by thinking about what does \"orthogonal\" mean in geometry. Two lines are orthogonal if they have are 90 degrees from each other in euclidian (x and y) space. The way you represent variables in the math of statistics is in a surface of multiple variables (let's just think of two to make it simple). If I can chart one variable along the x axis and one on the y axis, then the math becomes much simpler because I don't have to take into account the relationship between the two. That means your variables are orthogonal and you can simplify the equations.",
"Independent, unrelated. For example, whether someone likes cats or dogs more is (probably, didn't check) orthogonal to their body weight, but weight is correlated with overall health status."
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mfdt31 | How do farmers control whether a chicken lays an eating egg or a reproductive egg and how can they tell which kind is laid? | Biology | explainlikeimfive | {
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"Chickens lay eggs whether they are fertilized or not, so the easiest way to make commercial eggs is to not allow the males to mix with the females. But if you need to check an egg you just hold it up to a bright light. You can see enough through the shell to tell if a chick is in there. Commercial operations do this with automated machinery.",
"Chickens will lay eggs no matter what. It’s basically a daily chicken period. Only if they are fertilized by a rooster beforehand will they form baby chicks. If you keep chickens away from roosters, all eggs will be eating eggs. Edit: I know both fertilized and unfertilized eggs can be eaten. OP said eating eggs and reproductive eggs so I stuck with the same terminology assuming they meant how do farmers know what eggs are able to become chicks and which ones won’t.",
"Hens lay fertile eggs within about 3 weeks of being 'visited' by a rooster. She then doles out the semen one egg at a time as she lays a clutch. After laying as many as she wants to incubate, she sits on them, keeping them uniformly ~99° F for 21 days. Fertile eggs are indiscernible from infertile eggs and can only be proven one way or the other by incubating or cracking them open. Only a trained eye can tell the difference, even by cracking and examining. Noticeable development is only present after 5-7 days at incubation temperatures. Eggs are generally collected within a few hours of being laid, so there's normally no danger of finding any development, as they aren't incubated. TL;DR: Farmers collect eggs regardless of whether they are fertile or not. Fertilization is absolutely irrelevant, as a normal person couldn't possibly discern whether the uncracked egg was fertile until day 8 or so of intentional incubation. They look and taste the same either way. *Somehow deleted part of my response while trying to fix a typo, sorry!",
"All eggs are eating eggs unless you want to hatch more chickens. Hatching eggs require fertilization from a rooster. On commercial farms, hens that lay eating eggs rarely, if ever, are given any 'private time' with a rooster. They may bring in a rooster to give them motivation but not allow fertilization. My family raised chickens when I was a kid and we had a rooster. There is a visible difference when you crack open a fertilized eggs because the yolk and the egg white are joined together by threads or tubules. I don't recall the eggs tasting any different (Summertime eggs were definitely better because the chickens were eating a lot of bugs. The yolk is a deeper yellow.)",
"The eggs will only be fertilized if a rooster has done his job. You can eat eggs whether they’re fertilized or not. The embryo doesn’t develop unless the egg is incubated either by a hen or a machine. Eggs can be “candled” to see an embryo.",
"> How do farmers control whether a chicken lays an eating egg or a reproductive egg You remove any roosters from your farm > how can they tell which kind is laid? They're the same thing. If you get a fertilized egg soon enough (eggs are usually collected in the morning or at night every day) then a chick won't grow and you can eat it like it was never fertilized at all",
"Hens will lay eggs regardless of whether or not they’ve been fertilized. So it’s pretty easy to make sure you’re only getting food eggs - keep the rooster away from the hens.",
"Let’s see a show of hands. Who is thinking of a non-egg breakfast alternative for tomorrow? Cuz I sure am.",
"Okay.... who's going to ELI5 the birds and the bees here?",
"Just collect them everyday and it won't matter if they are fertilized or not. Hens have to sit on them and keep them warm for an embryo to develop. If you want to hatch them, you generally put them under a heat lamp for a while.",
"Farmers try to control this by not allowing the chickens to mate except in specific circumstances, but this isn't always a perfect process: preventing chickens from mating can be harder than you might think. As a second line of defense, they use a technique called candling to detect embryos. This involves holding the egg up to a strong light and looking through it: it's not *quite* as simple as the process you may have seen in cartoons, but it's pretty close. It takes some skill to read what's going on inside the egg, especially at early stages, but you can get a decent read on which eggs are fertilized and which are not.",
"As an additional note to what others have said, many farmers have a variety of chicken breeds on their farms. Some breeds of chickens instinctually are more attuned towards nurturing eggs by sitting on them. Other chickens have been bred to just pump out eggs and will not sit on their eggs, thus, even if they are fertilized they won't grow up to become new chickens. So in a way, another method of controlling reproductive eggs vs eating eggs is through the choice of chicken breed. I know this from working at an organic farm, but even there, they had incubators to ensure certain eggs successfully led to new chicks being born.",
"I once cracked sn egg into a frying pan and there was a fleshy lump sitting there sizzling away. I did not have eggs that day",
"When a mommy chicken and a daddy chicken love each other very much they get together and cluck making more chickens in the process. If kept separate the mommy chicken will keep cranking out duds.",
"Fun story: my boyfriend’s dad had about 10 free range chickens and one rooster. Our favorite chicken was named Sally and the rooster was Slick Willy. One day I got to bf’s dad’s house and there were three little babies following Sally around. Ask my bf about it and he had no clue what I was talking about until I took him outside. Turns out those three eggs were never collected and Sally and Willy ended up having three babies. One of the coolest experiences raising them from new born chicks. They were so used to people and would hang out with us all the time.",
"You keep the rooster dick away from the chicken vagina and you only get nonfertilized eggs.",
"have you never opened an egg and saw a brownish embryo looking thing attached to the yolk? they are all \"eating eggs\"",
"All eggs are eating eggs. The only difference with fertilized eggs is how soon you collect it out from under the hen! If you collect daily, you can’t tell the difference when using them. Chicks only grow at specific temperature and humidity.",
"There’s no such thing as ‘an eating egg’. Not all eggs are fertilised but they all exist for the purpose of reproduction, just like human women don’t produce eggs for any other reason.",
"Not exactly ELI5, but I heard the perfect response recently to this question; > The egg is a women's **Period** To those who never did sex ed. When a women has a period, she's basically ejecting the egg that has been waiting inside her to be fertalised. Because its not fertalised it ejected. For a chicken its ejected whether its fertalised or not.",
"they don't, they just eat eggs regardless. In industrial farming they kill the male chicken so the females won't have fertilised eggs",
"When a boy chicken and a girl chicken love each other very much, they fertilize an egg in a very special dance. If you want eggs for breakfast, just keep the boys away from the girls.",
"Interesting side note: President Calvin Coolidge and his wife were touring a chicken farm. Mrs Coolidge asked the manager “ does the rooster copulate once every day?” The farmer answered “no, the rooster copulates dozens of times every!” She said “tell mr Coolidge!” The farmer told President Coolidge. He said “Same chicken every time?” And the farmer said “No a different chicken every time!” He said “Tell Mrs Coolidge.” So now, a male’s ability to be sexually re-aroused by different females is called the Coolidge Effect... ( and subsequently makes the porn industry possible, since all the fappers have trained their brains to think they are mating with multiple partners!)",
"not a farmer but my friend owns a few geese and he claims that they lay eggs whether or not they contain little baby geese in them. He thought that the same might be the case for chickens and so he later adopted some and got the same result. He said that you’ll know if the egg contains a chick if the hen is being overly protective of it by sitting on it most of the time to keep it warm. If the egg doesn’t have a chick in it the hen just leaves it there. I’ll spare everyone of the horror of how he confirmed this by excluding it. This is an explainlikeimfive after all"
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mfe8z5 | What does ‘a means to an end’ mean and ‘the end justifies the means’ mean? | That was a mouthful for a title, but yeah, basically what I wrote in the title, can anyone explain, I can’t wrap my head around it. And could you use an example please? That helps a lot. Thanks :) Edit: thank you guys for responding so fast! I think I get it now :) how would you use it in a sentence using your examples? | Other | explainlikeimfive | {
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"\"The ends justify the means\" generally relates to doing something morally wrong to accomplish a moral goal.",
"\"A means to an end\" = a thing that's not too useful on its own, but it helps you achieve a goal that you need. Like, for many people, a car is just a way to get from home to work - they treat their car as a means to an end. \"The end justifies the means\" = a good outcome or result is worth the actions you have to take to get there, even if those actions are immoral, unethical, bad or \"wrong\". An example is how politicians will lie and make promises they know they won't keep in order to get elected. To them, the end (getting elected) justifies the means (making promises that they might ignore/forget about after being elected)."
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mfeaw1 | how would brown water come up your tub/shower drains during a storm? | Background: New subdivision, construction ongoing. Multiple houses having issues (standing water in yard or lots of mud brought into yard) with storm water drainage in their yards. After a big storm last night a homeowner posts pics of water damage throughout their house with brown (mud vs ?) water standing on floors. They said water flowed up through their drains and flooded the house. So how would that happen? And, if applicable, shouldn’t tub/showers drain to a sewage treatment plant vs drain with other rainwater? | Other | explainlikeimfive | {
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mffduv | the "new physics" being discovered at Cern. | URL_0 | Physics | explainlikeimfive | {
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"Physicists have put together over the years the \"Standard Model\" which describes all of the sub-atomic particles and how they combine/decay into other particles (and how often). A recent paper from CERN describes how they *might* have evidence of an error in what the Standard Model predicts vs. experimental results. This is important, because there is a pretty strong belief that the SM is incomplete and overly complicated, and that there's a better model out there if we could figure it out. Finding specific flaws in the existing model is one of the best ways to come up with a better model (and know that it is likely more correct). Additionally, we now believe that there are 4 \"fundamental\" forces in nature. It is a *possibility* that this experimental data is evidence of a new, unknown force that isn't in the SM. But the key word is *might*. The existing experimental evidence could just be a fluke. It's kind of like flipping a coin, since it is based on probability. We know that when we flip a fair coin, 50% of the time it should come up heads and 50% of the time tails. But when you run experiments, you don't get exactly 50/50 every time. You need a lot of coin flips to get close enough to 50/50 to be statistically certain that you have a fair coin. There's always a possibility that you get way too many heads or tails just as a function of chance. The CERN data is pretty strong, but not yet strong enough. They need a lot more certainty before being able to say for sure that the Standard Model is broken in that particular manner. And it would be helpful if it was also replicated elsewhere, to reduce the odds of experimental error. These experiments are very difficult to run.",
"**Background / The basics:** Scientists in Cern use a large machine called a particle collider because this is all it does: collide very small (smaller than an atom) particles or parts of atoms together in a continuous beam. Having recorded trillions of these collisions the scientists and their computers have learned a great deal about how these particles usually behave when they collide, so they have made many predictions and combined all their knowledge into a big unified theory they call The Standard Model. (SM) The SM is not perfect because it cant explain everything we observe in the universe or even in the big collider, so more work is needed and the scientists comes up with new ideas to explain what is really happening. When these ideas are tested, sometimes they see a result that surprises them. And at Cern surprises like these can be good because they indicate new things in nature we dont know about yet. **This experiment specifically:** I this case , the Standard Model predicted a certain result, but they saw something else. Imagine you are shooting two new strawberries at each other over and over and you photograph the collision with lots of fast photos. Each time you expect to see the same certain things: lots of strawberry juice droplets, some small some bigger, you expect seeds and so on , but now you see something new: you see some of these small seeds suddenly behaving like they are super heavy and big and going really far. The question the scientists are asking is why are they behaving like this? Why are they going so far? is it a new force of nature acting on them or is it something else? To answer this, more tests are needed.",
"In the standard model, electrons belong to a family of particles called leptons, which also includes the mu and the tau. The three essentially behave identically - the only difference is their mass. What was observed here is that b quarks decay into electrons more often than they decay into muons, which is odd because electrons and muons should behave essentially the same. Having such a discrepancy is not inherently a problem with SM, since we know a lot of reasons why particles would prefer to decay to one lepton over another. However, all such examples are relatively easy to explain by combining our understanding of the weak force with basic physics principles. For example, even though the tau largely behaves the same as the other two, it is the most massive, so it can only appear in high energy decays based on energy conservation arguments. A more sophisticated example would be that charged pions decay to muons more than electrons. This is because this decay occurs by the weak force, and the weak force has a preference for certain angular momentum configurations, so we can explain this based on angular momentum arguments. The main point is that all of this “lepton physics” is well understood and has been studied for a long time. What’s different about this is that they ALSO tried to apply lepton physics to this, but it didn’t work. Hence, they were forced to conclude that the discrepancy is due to the b quark simply having a greater affinity for the electron than the muon. This is surprising because there’s no reason for the b quark to decide among the leptons which one it likes. After all, the b quark mostly follows quark physics, which doesn’t even interact with leptons. Moreover, since the b quark is over 40 times bigger than either particle, the mass difference (that is, the only difference) should be negligible. So, apparently something from quark physics can distinguish leptons, even though as far as we know leptons don’t even appear in quark physics. This is the idea of the contradiction, and it can’t be put to rest quite yet because there’s a lot of quark physics we don’t know. tl;dr e and μ are similar particles called leptons, which follow lepton physics (easy). b is a large particle that follows quark physics (hard). Lepton and quark physics should be 100% independent. However, we suspect that b prefers e over μ. If correct, the discrepancy can’t be explained by lepton physics, so it lies in quark physics, which mean that leptons are appearing in quark physics when they shouldn’t. This makes quark physics harder, but also more interesting. (edited for typos, some sentence structure, and the tldr)",
"The simplest answer I can come up with is that at the subatomic particle level (as in the things that make up protons, neutrons, and electrons) our \"standard model\" doesn't fit perfectly. These subatomic particles only sometimes act like we expect them to. So making accurate predictions has been difficult. Though the more we observe these particles with experiments like what's happening at Cern, the more we understand. One famous example is known as quantum entanglement. Certain subatomic particles have a \"spin\" to them. Sometimes those subatomic particles are considered \"entangled\" with another. Where if we change the \"spin\" of one, the other will react instantaneously. This happens regardless of distance. If we separated the entangled pair on two different sides of our galaxy, they would each change at the exact same moment. This defies the standard model's understanding of the speed of light where no information can travel faster than light through a vacuum. If it did it would take as long as it would for a photon to travel from one particle to the other to change spin.",
"A lot of science isn't \"eureka!\" but... is more \"hmm... that's odd\". Spotting the weirdness vs what's already known produces theories... some of those produce new science. In this case the CERN data seems to be pointing at weirdness in what we know of how the \"Standard Model\" works. This is likely to eventually produce new understandings as the weirdness is worked out, test and better understandings of it affect our existing knowledge."
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mfgcfx | why did the copper on the statue of liberty turn green but copper mugs and copper pipes don't? | Thanks for all the responses. It seems like it's just a matter of time, and the elements. What got be thinking is the pipes in my house are from the 60's and the exposed pipes in my basement are still very copper looking. But I understand now that they are not exposed to elements, especially a salt water harbor. But given time they will oxided. Thanks for the responses. | Chemistry | explainlikeimfive | {
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"Copper pipes do oxidize and turn green over time, especially in wet environments. I assume copper mugs do too if you don't clean them regularly. However it takes quite a while for a green patina to form on bare copper. According to some cursory googling it took the Statue of Liberty between 20 and 40 years to turn totally green. It was also completely exposed to rain, unlike most household copper piping, and industrial air pollution supposedly had an affect also.",
"Those copper mugs and pipes will eventually tarnish just like the statue of liberty. The green tarnish is the copper equivalent of red rust on iron. Just oxidation of a different metal.",
"They do. Those things aren't typically constantly exposed to the elements though, like the statue is.",
"There's a pretty big difference between a piece of copper that has been fully outdoors in the middle of New York Harbor for almost two hundred years and a pipe that's encased in a wall. Moisture and salinity are what contribute to copper corrosion; interior pipes are mostly protected from both because they're enclosed in walls.",
"As others have said, it’s mostly a matter of time and weathering factors. If you look at really old plumbing, it’s green, too. My grandma’s house was built in the late 1800s and had some original plumbing until at least the mid 1980s. I remember being in the basement and asking why she had green pipes instead of shiny copper like my (less than a decade old at that point) house. The answer was along the lines of “It’s really, really old and we’re too afraid to look at it very hard, much less actually try to replace it.” For a slightly more modern example of large scale outdoor copper oxidation, check out photos of St Josephat’s Basilica in Milwaukee, WI. It was built about 125 years ago, and the roof of the dome is copper cladding similar to the Statue of Liberty. In the early 1990s, the roof was the classic old penny blue-green color. The cladding was completely replaced in 1997 and the shiny new copper was bright enough that it caused problems when the sun was at an angle to reflect into evening rush hour traffic. If you look at current pictures, the roof has faded considerably and now resembles a not-old-but-not-new penny. It’s not bright enough to shine anymore (fortunately for those trying to stay on the road on that part of I-43), but it’s still a dark metallic color. In another few decades, the roof will be Lady Liberty Blue, and probably need to be replaced again in a century or so."
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mfgqvc | We breath the through the lungs. The air goes in and out of our lungs. So why is it that most of the time it's our stomach that inflates rather than the chest? | Biology | explainlikeimfive | {
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"Your body can expand the lungs 2 ways, the ribs can stretch out to expand your chest, or the diaphragm under the lungs can expand into your gut which pushes your gut outward. You have probably been breathing with your diaphragm.",
"Your diaphragm, a big, flat muscle located under your lungs, pulls down to create a void in your lungs. Air then fills that void which is you \"breathing in.\" When your diaphragm pulls down, it runs into your stomach, liver, etc. Those bois have to move down/out/backwards to make room for the diaphragm to lower. That's why your stomach might look like it's filling with air, when really it's just moving out of the way for your lungs to fill with air."
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mfh3ni | Why your printer needs magenta just to print in black and white? | I get printers are way advanced now... but why do I need color(magenta) to simply print in black and white. | Technology | explainlikeimfive | {
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"Because the people who made printers want you to buy a new printer cartridge. They make close to nothing on the printers, they make money on the inks. They've configured the computer programming parts of the printer to say you are out of ink, so you go out and buy more ink.",
"The *only* reason is they want to sell you more expensive ink. Buy a printer with \"eco tank\". Then you can buy bulk ink without ever needing a cartridge again.",
"If your printer is a 4-color, you have a black cartridge, and should have a “grayscale” option in the settings that forces it to only use the black cartridge for everything in a print job."
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mfh4q4 | How do power plants actually make electricity? | Technology | explainlikeimfive | {
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"There are lots of types of power plants, but most work in one way or another by turning a turbine. The turbine spins magnets in a metal coil which pushes the electrons in that wire and that is what creates the electricity.",
"Something inside the plant creats physical work. This can be burning coal to heat water to spin a turbine, or letting the wind push a fan blade to spin a turbine, or allowing water to fall onto a wheel to spin a turbine... I'm sure you see a pattern here. That turbine is connected to a system of magnets, which are spun around using the turbines. And by placing copper cabling next to the spinning magnets, an electric current begins to run through the cable.",
"Steam turbines. At the very basic level, water is heated to steam to turn a turbine and that kinetic energy is converted to electric energy. Most often, fossil fuels are the primary source of heat, but nuclear power plants use nuclear energy to heat the water instead."
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