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nwmerp | what exactly is an internal monologue? | Biology | explainlikeimfive | {
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"Imagine you have a problem, you go down everything that could be the cause of that problem, what each thing would have to do to cause that problem, then every solution to fix each of those issues. Now imagine you said all of that stuff out loud, except your voice never came out and just remained inside your head. That's an example of an internal monologue.",
"Watch the series \"You\" on netflix - we get all of the guy's inner monologue so id be a good example? Its just the conversation you have with yourself at all times."
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nwmvcp | How can light bend? | Physics | explainlikeimfive | {
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"Hi! 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 mass-energy 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 is why gravity is a fictitious force: The reason why two objects in a gravitational field may experience relative acceleration is not a force between them, but geodesic deviation between two force-free objects. **That is why photons are affected by gravity: photons follow geodesics through spacetime, and the presence of mass-energy curves spacetime. Therefore, the straight lines that photons follow through this curved spacetime appears curved to outside observers.** If you have any more specific questions, feel free to ask. ----- For a great video on the basics of GR, check out [this]( URL_0 ) video by PBS Spacetime.",
"Light bends when it changes speed through an interface (like air to glass) at an angle. This is because light has some wave-like properties and when waves change speed at an angle they also change direction. This is how lenses work. Light also can appear to “bend” because light follows straight lines in spacetime and mass bends spacetime (aka gravity). So the light’s really going “straight” in locally bent universe.",
"Two ants on a sphere, like the Earth, start on the equator, say one in Africa and one in South America. They are both facing North and they start walking. Eventually after much time they eventually meet up at the North Pole. They never did anything other than go in a *straight line.* Yet, even though the ants started off very far apart they ended up being pulled to each other. This is what happens to light when it’s near gravity. It feels like it just goes in a straight line but the underlying space that it travels in is diverting it go somewhere else. In fact this is what all objects do when it is affected by gravity. They think they’re just going in a straight line - minding their own business - but gravity curves the space they’re moving in (like the curvature of the ball our ants were moving on) that they deviated from a straight line."
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nwn5pn | How does heat turn into light? | How does thermal energy, which is also kinetic energy turn into light (infrared)? Where does this conversion happen? | Physics | explainlikeimfive | {
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"Heat energy when applied to a surface will cause electrons in that objects atoms to enter an excited state. Basically a state with higher energy than their ground state (the lowest state, where the total energy of the electrons can’t be lowered past). As you start adding more thermal energy, more electrons will enter the excited state. This state doesn’t last forever and as they lose energy they can emit a photon of visible light when returning back to the ground state or a lower energy state, the more energy and the higher state they enter will release a photon of greater energy producing light. Most objects when they get to about 550 degrees Celsius will start to glow a dim red. The visible spectrum of light, that is Red to Violet, is actually quite a narrow spectrum. Edit: If you are more than just casually interested in this topic consider looking up explanatory videos on - Plancks law of spectral energy density, Wien’s displacement law for black body radiation, the Stefan Boltzmann law of black body radiation and the Ultraviolet catastrophe, the dispersion of light into its principle colours and the twin slit experiment. Alternatively the light and radiation section of most good physics textbooks should have some good information as well as information on the above."
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nwnabo | ; why does water make skin sticky but road slippery? | When skin is wet it made clothes come off or put on more difficult but when road is wet it made tire more slippery. | Physics | explainlikeimfive | {
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"Water loves to stick to itself but doesn't have much friction, at least compared to asphalt. When you're wearing a wet shirt, water in the shirt wants to stick to water on your skin. When you're driving, the tires and asphalt need a huge amount of friction between them to keep the car from slipping. On the scale of cars, water's tendency to stick to itself is too weak to matter noticeably, so all you notice is the slipperiness due to the missing friction",
"It's actually just the amount of water. Water sticks to itself (which is why it forms droplets instead of completely spreading out when spilled), but being a liquid it also is far easier for an object to travel on the surface of water than to slide against most solids. When you have a small amount of water, there's not enough to get any change in friction BUT you can feel the water sticking together slightly. With enough water and particularly with enough speed, the \"sticking\" part is basically irrelevant compared to the change in friction."
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nwotc9 | Why do open wounds burn when touching them? | Biology | explainlikeimfive | {
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"PIEZO2. It is a protein that is sensitive to pressure, one of the things that makes us feel touch at all. Researchers have found that after an injury that protein becomes hypersensitive, something called \"tactile allodynia.\" It's why when you're sunburned, even putting on a shirt is painful. It's probably evolutionary. Our bodies way or saying \"hey don't touch that it's healing.\"",
"So that you will stop touching them so that it can heal efficiently. The inflammation and exposed tissue of an open wound increases the sensitivity of the area. It is a benefit to us because the more we touch/mess with/aggravate healing tissue, the longer it takes to heal, and the worse it heals. The increased pain signals our body gives us in these situations helps our bodies heal better, and faster. Some think the overuse of pain medication can contribute to poor healing for this reason. You hurt yourself, it hurts, you take Advil, it stops hurting temporarily, you go about your business- BAM! necrotizing fasciitis 🤷🏻♀️",
"It is that way so that you can monitor the wound. If anything is touching it, it could be a vector for infection so the body makes you keenly aware of it so you can care for it. It also has to do with moisture loss from a wound. As moisture is lost it causes temperature cooling from the area which makes anything touching it that is above that temperature, feel warm."
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nwpwys | How does the Portuguese Man o’ War reproduce if they are made of separate organisms working together? | Biology | explainlikeimfive | {
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"The \"many separate organisms\" thing is often described in a misleading way, as if they were distinct species of animals joining together. Portugese Man o' War _are_ made of a collection of multiple organisms in one sense, but those organisms are all clones of each other and they are all connected. I don't know if you know anything about coral, but a coral is a bunch of polyps (a bit like teeny tiny sea anemones) all joined together and growing on the same stony \"skeleton\". Or maybe a more familiar example, consider how a strawberry plant can produce new strawberry plants that stay attached to the original with runners. Anyway, portugese man o war do the same thing. The subunits (the organisms) are called zooids, and there are a bunch of them in the man o war, all clones off the original one. What makes the man o war and its relatives special is that (unlike with coral and strawberries) the zooids come in several very different specialized forms. Some function as floats, some help propel the animal, some function as tentacles to catch food, some function to digest food, and some function for reproduction. You can think of it a bit like how an ant colony might have a specialized queen and worker and warrior ants...except here all the \"ants\" are stuck together. Anyway, to answer your question the way reproduction works is that the reproductive zooids do the reproduction for the colony. Since everything in the colony is a clone, genetically it doesn't really matter which one actually does the reproduction, the genetic material of all of them get passed along. EDIT: here's a cool video on how siphonophores (the group that includes man o wars) grows. URL_0",
"The separate organism is a bit misleading. It's mostly a way to describe how they grow. For example your right leg started from inside your body in the womb and got bigger. If you were a man o war you'd clone yourself, and attach the tiny clone embryo to your right hip, with the embryo coded only to grow a right leg. And so on for the rest of your body. That leg is technically not yours because it's from a clone. They also clone reproductive organs to spray their..stuff around the ocean. But even if clones on the manowar have different functions they all share the same DNA, so we can confidently say this or that man of war reproduced."
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nwpz4b | Why do software installation or updates always go very fast up to 90% complete, then the last 5-10% takes so much longer? | Technology | explainlikeimfive | {
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"You shouldn't really listen to anyone here. The answer is that it's implementation dependent. Maybe the engineer wrote it so that there are four steps of 25% each. Copying files is maybe step 1 and is super fast. Step 2 is a big database operation and is slow... etc. Maybe the steps are totally fake. Maybe there is a simple timer that moves the progress up 10% every second until 99% where the last percent is actually dependent on something. Its completely unique to the person who programmed it or a commonly used installation software.",
"Basically, the computer has no idea how long it's going to take. It knows there is X number of steps and how far a long It is for each individual step and its going to try and predict how long it's going to take based on the information it been given by the dev inatally. There might also be a psychological explanation as well but I'm not sure Edit: [tom Scott explains it so much better]( URL_0 )",
"That first 90% is you dumping a moving box all over the floor The last 10% is putting everything away nice and neat",
"I've actually developed loading bars for applications before. 99 times out of 100 a loading bar is set by dividing the number of tasks to accomplish by the number of tasks already accomplished. Rarely is there any consideration to the length of time it takes to do a task. If there is, it's a best guess. Not many people want to pay for time studies to get it to be a realistic loading bar. They just want a notification of progress so they don't think the application is frozen. Just for kicks and giggles. I have done a time study on an application loading and normalized the loading bar to be fairly accurate as a countdown. On the computer I was developing with. I transferred the application to a user's computer and it was way off. (Maybe my HD was fast or slower than the user's, or their network connection was flaky. Who knows. There's a million reasons). Not saying you can't figure it out, but no one is going to pay a developer to do it.",
"The progress bar is nothing but a guesstimate. So the first 90% is guessing, the last 10% is the installer realising it is way off.",
"TL;DR Most software \"loading\" bars are fake. Meaning they don't actually show the precise percent of the progress. It's a guesstimate! Source: Me! A manager in software testing with just over 10 years of experience",
"Computer aphorism: The first 99% of the install takes 99% of the time. The last 1% takes the other 99%.",
"It's not a linear process but to make things \"user friendly\" interfaces are made with an assumption that things indeed are linear. The code that shows you \"% done\" only knows about the tasks that need to be done, not how long each task will take. So if the early tasks are very simple tasks, but the latter tasks are very complex tasks, it will appear to slow down as you see a % done being calculated.",
"Think like you're carrying a box with lots of toys in it. You need to take it from the living room to your room and place all them in the right spot. Someone decided 90% of the work just carrying the box, 10% is putting them on place. But carrying the box is quick, you can do it in a minute. Putting the toys in place takes a lot longer, maybe 4 minutes.",
"An accurate progress bar is difficult to code and are not critical so many are done as a last minute best effort. There are examples in the past of progress bars that were designed to go up to a set percentage over a period of time independent of the actual state of loading. Once the time was done, it would stay at that set percentage until everything was loaded. This caused a lot of frustration as computers became faster but these programs refused to start until at least 10 minutes went past. TLF5YO: Progress bars are hard to get right but as long as it is moving everything is going to be okay."
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nwqve9 | what happens in your head when you drank a lot and you start ‘spinning’, and why lying on one side has an effect on the nausea? | Biology | explainlikeimfive | {
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"A part of your inner ear called the cochlea has hairs submerged in fluid. When your head turns, the fluid tends to not move as quickly as the cochlea does. When those hairs are being pushed against the fluid, that's how your brain senses motion and rotation. The nerve signals in the brain from the cochlea are being disrupted by alcohol and the byproducts of your body processing it, just as many other signals are. That's the feeling of drunkenness."
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nwqvgp | What is the goal of this so called Great Reset? | Economics | explainlikeimfive | {
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"It's a concerted effort by billionaires and the hedge fund industry to buy up property all over the place at inflated prices to turn it into single-family rental housing. It's a massive redistribution of wealth scheme by the rich, and it's destroying the American Dream. URL_1 URL_2 URL_0",
"There is currently no government policy associated with a \"great reset.\" A few \"global forums\" have used it as their theme in the last year. These are basically big events where rich people go to network and talk about stuff. There the idea of the \"great reset\" is that COVID has stalled the economy to the extent that there are significant opportunities to resume economic activity in ways that are more equitable or environmentally friendly. Up to you how useful or sincere you think those ideas are or whether they'll have any actual influence on government policies. \"Great Reset\" sounds big and scary, so it's also been the topic of baseless conspiracy theories. No idea what the other guy is talking about. More single family homes are being rented rather than owner-occupied, but this doesn't seem to have anything to do with the phrase \"great reset\"."
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nwrj84 | What is a register in computers? | I know when a program is running it uses registers to load and execute on data. However I keep hearing about hardware registers. Are there other kinds of registers outside of the CPU registers? May be registers that are available to other hardware modules or shared between hardware modules? I am thoroughly confused. | Technology | explainlikeimfive | {
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"Registers are simply active data storage areas. Nothing particularly fancy about it. Registers are available in many types of ICs and come in many varieties. For example, you can have status registers, control registers, data registers etc. The reason to give them names is because the function of these registers have to be very carefully explained in the data sheet for the ICs and it is just convenient to give them a name. Registers are typically not shared (since they are implemented internal to an IC). Unless you are poking deep into the HW and chips (eg writing drivers etc), there is rarely any reason to interact with HW registers (and attempts to change register settings without knowing EXACTLY how they will change the function of the hardware is very unproductive) Go pick up a few data sheets of some simple control ICs and you can see how they explain register settings etc."
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nwrqz2 | Why do the balls in spray cans make it sound empty when you shake them | Other | explainlikeimfive | {
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"If they were empty, then you’d hear the balls create a sort of ~~echo~~ ‘peal’ as they cause the can to vibrate, a bit like a bell. When the cans are full, the vibrations are dampened by the liquid mixture, and you only hear the impact of the ball with the thin wall of the can, which is easily transmitted to the air."
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nwryq4 | Why does stretching your body feel good? | Biology | explainlikeimfive | {
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"Part of it is just the going from tight to loose. Our reflex to feel the need to stretch is automatic (from the autonomic nervous system - so auto nerve spark) and satisfying that releases pleasure chemicals (like relieving the bladder)."
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nwsi0n | How did Max Planck come up with the idea of quantization from the black body radiation and how did he conclude that? | Physics | explainlikeimfive | {
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"The idea of quantization came about from needing to solve a problem known as the \"ultraviolet catastrophe\". If you try and construct a simple model of blackbody radiation using statistical mechanics you will end up with an approximation known as the Rayleigh-Jeans law. This law predicts the blackbody spectrum quite well at low frequencies, but it has a big problem in that it states that the power emitted at a given frequency is proportional to the frequency squared, with no bound. This implies that all black bodies should be emitting infinite amounts of radiation at infinitely high frequencies, which obviously does not match with reality. To solve this problem Planck kind of came at it backwards, he first figured out empirically what the equation describing black body radiation is, and then attempted to derive a physical explanation. This came from assuming that in a blackbody there are a large amount of harmonic oscillators which have a finite number of possible frequencies, taking this assumption it is then possible to derive Planck's law."
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nwstqd | Why does every physical trainer want me to inhale through my nose and exhale through my mouth? | What the title said. I just can't get used to it, it feels unnatural and uncomfortable. Thank you. Edit I fogot to add that I mean during workout, of course :) Edit2: what I can't seem to learn is the mouth part. Naturally I would inhale and exhale through the nose | Biology | explainlikeimfive | {
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"It controls your breathing and prevents hyperventilating. It also helps you oxygenate better when you have physically exerted.",
"> What the title said. I just can't get used to it, it feels unnatural and uncomfortable. Thank you Well, walking may feel unnatural to someone who never learned to walk properly. Breathing through your nose is your body's default. You nose employs filter mechanisms for particulates and contaminants that would be completely bypassed when inhaling through your mouth.",
"I always thought it being unnatural was kind of the point. It makes you be more aware of your breathing so you take slower, deeper, more purposeful breathes; to help keep from hyperventilating or holding your breath.",
"To add onto other comments... breathing through your mouth in cooler weather can cause bronchial spasms. Cold air hits warm organs and they contract. It can trigger an asthma attack in sufferers, but it can lower oxygenation even if you have no asthma issues. Tight, contracted tissues don't flex as well. Source... I have cold-induced asthma attacks and \"in nose/out mouth\" was the advice from my pulmonologist."
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nwuhvj | If telomeres shorten with every cell division how is it that we are able to keep having successful offspring after many generations? | Biology | explainlikeimfive | {
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"There’s an enzyme called telomerase that repairs the telomeres. In most of your cells the genes to produce it are deactivated, but it remains active in reproductive cells and a few other spots with very high turnover. Reactivating the telomerase gene is a critical mutation for cancer as well - cancer cells need to repair the damage they do to themselves during runaway replication."
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nwukmi | what is HDR (High Dynamic Range) | I just don't get the technical explanation. It's not just a wider color gamut. It does something more/else but I just can't seem to understand it.. | Technology | explainlikeimfive | {
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"If a scene has bright stuff and dark stuff in it at the same time, it can be hard to photograph. If you use a slow shutter speed, so a lot of light reaches the camera, you'll get enough light to see detail in the dark areas, but you'll get too much light from the bright areas, so the bright stuff will just be solid white. If you use a fast shutter speed, letting only a little light in to the camera, you'll get a good detailed image of the bright stuff, but the dark areas will just be solid black. You can't really capture both the bright details and the dark details in the same image. HDR is like taking two images, one that captures the bright details and one that captures the dark details, and then merging them together. That way you get detail in both bright and dark areas in a single image.",
"It's not just about more colors. It's also higher contrast. Meaning, with proper HDR you can have very bright and very dark objects **in the same frame**, and be able to see more details in both extremes."
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nwwspm | why isnt there protein in capsules like there is for vitamins? | Biology | explainlikeimfive | {
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"You need 50+ grams of protein per day to stay alive. Since most capsules hold 1/3 to 1/2 a gram of stuff, it would take a lot of them.",
"That'd be a bigggg pill Say you want the rough minimum of 50 grams of protein, how much is that? Well for fats you can use a handy reference point - butter. A stick of butter is 113 grams and 92 grams of fat so its basically as dense as you're going to get. That means if we make something similarly protein dense you'd need to eat the volume of a half stick of butter to get your minimum protein levels for a day That's going to turn into either a lot of medium pills or a few really big pills (Mucinex will seem small). As appealing as it seems to not have to cook, its surprisingly difficult to swallow a large number of medium sized pills and rather unpleasant. A 100 count bottle of tylenol only masses in around 11 grams so you'd be having 4-5 of those *per day* Ewww",
"It's the volume. You need a lot of protien. Bars and drinks seem to be the preferred delivery method besides diet",
"Are you asking specifically about capsules or are you looking for protein supplements? Protein supplements are definitely a thing. Protein is a macro nutrient instead of a specific vitamin, so there are a large variety of proteins. They'll mostly interact similarly for you though.",
"The amount of vitamins in those capsules is measured in micrograms. You need very little of them. When you're working out, you might be aiming to eat like 2 g protein per kg of body weight each day. So a 100 kg guy needs 200 grams of protein per day. That's nearly half a pound of pills, even if you could get them to be 100% pure protein (you can't). Even for a more modest protein intake you'd be looking at \\~hundreds of normal-sized pills a day to get enough protein. Protein powder supplement does exist. You've maybe seen it, it comes in those [huge bottles that look like vitamin bottles]( URL_0 ) but have like 10 lbs of powder in them and come with a scoop. And that's why the bottles are huge, you need to use scoops of the powder to make a shake. Sure you could take those scoops-worth of powder and put them into 57 huge capsules, but no one wants to do that when you can just make the powder taste like chocolate(ish) and drink it in 5 minutes."
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nwwt21 | Why do cars depreciate more than other consumer products? | Cars depreciate so much from even pulling off the lot. 20-30 percent gone after the first year and 15-20 percent every year after that. I would imagine that inflation would make it somewhat of a gradual decline. Even if you pay your car off in 36 months, minimally, half the value is already gone. No other item faces this kind of depreciation. | Economics | explainlikeimfive | {
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"Actually most other consumer items generally have even worse depreciation, try selling second hand furniture, white goods, clothes etc",
"It's actually simpler than you'd expect, cars are one of the most expensive things that we own that are subject the most relative wear and tear as most people use them every day. Even within a year of use it's possible the car can take a beating and may need some parts replacing."
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nwxewg | What are the main forces driving inflation in the U.S. right now? | Economics | explainlikeimfive | {
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"The eye popping numbers are in large part because they look at year over year comparisons. Think about where the country was last May vs. this May. The economy came to a halt, tens of millions were out of work, other business was drastically cut, demand for goods other than sanitizing wipes and toilet paper was low so prices were low. Now, everything's opening up, there's pent up demand, people have stimulus money, there are shortages of key components like microprocesors and lumber, logistics snafus like the ship stuck in the Suez Canal, and those fuel a jump in prices. As do labor shortages requiring higher pay. So last May was lower than usual, this May things are higher than usual. Looking at a multi-month trend may still show some inflation, but not as great as the small year over year snapshot."
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nwxgwv | What determines if a shot is intravenous or intramuscular? | Recently I got a B12 shot, and it was given in the fatty tissue of my arm. Wouldn't it be more effective in my veins? | Biology | explainlikeimfive | {
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"text": [
"Different routes provide different absorption rates. Some medications can be dangerous if absorbed too quickly others are essential to get into the body quickly (eg IV antibiotics). but since IVs are considered a more invasive form of administration that requires specialist training it’s reserved for when it is essential and when a fast response is needed. For B12 you can give it IV and you may get some mild symptoms such as a sweet sensation in your mouth but less invasive options are available and often considered first."
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nwxpc8 | How do some food products "contain traces" of completely different and unrelated foods? | Other | explainlikeimfive | {
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"Usually because they're made in factories with other food products. Some people are very, very allergic. So if there's even a tiny chance of contamination, it's important to note.",
"Different foods are prepared on the same manufacturing line and in the same equipment and it is quite difficult to remove traces of the previous run. A good example example is plain M & Ms which are labeled as containing peanuts. The M & M line makes both plain and peanut so there will be traces of peanuts in the plain candy. Since even small traces of peanuts can cause a severe allergic reaction M & M/Mars and their lawyers add the peanut warning to avoid reactions (and liability).",
"If they're made in the same place, where dust from one could drift over to the other. Or if they're made on the same machinery - even if it's cleaned inbetween batches, it's tough to get it absolutely clean of every last microscopic speck."
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nwyq96 | My Diet Soda lists on the label 0 calories per serving but 15 calories per container. Shouldn’t it be 5 calories per serving since there is 3 servings per container? | Mathematics | explainlikeimfive | {
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"text": [
"In the USA, the Food and Drug Administration (FDA) allows any food or beverage with less than 5 calories (4.99999999 is less than 5...) to label it as 0 calories. It's a stupid rule... [more information.]( URL_0 )"
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nwz56l | What is emotional maturity | I don't know and I want to | Other | explainlikeimfive | {
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"I think *emotional maturity* is the ability to take a breath between feeling an emotion and doing something about it. This lets you make a better choice. I'll give an example in three stages. **The Situation:** Someone says something that hurts your feelings. You feel **PAIN**. **Stage 1:** If you're emotionally ***im***mature, you immediately want to hurt them back. You say something nasty, or do something else to hurt them. Things go bad quickly. **Stage 2:** If you are emotionally mature, you take a breath. You say something calmly, like \"What makes you say that?\" You have now created a chance for things to end on a better note. * Keep taking slow breaths as you listen to the other person. If you reach your breaking point, say you need a while to think about this and walk away. (LPT #1: It is very hard to walk away. It takes practice. Don't get upset with yourself if you fail sometimes.) (LPT #2: If you feel like you're going to cry and you don't want to, try coughing. I read this somewhere and it actually worked for me. YMMV.) **Stage 3:** If you're ***VERY*** emotionally mature, you take two breaths: one to calm down and one to see if there might be any truth in the hurtful thing they said. If it's true, you own up to it. \"I see your point. What can I do to make this better?\" * Continue as in Stage 2. **Conclusion:** I'm a slow learner. It took me DECADES to get from Stage 1 to Stage 3, and I don't hit Stage 3 every time. I'm pretty good at Stage 2, though. As u/denUil said, it's a skillset you develop. Some people develop faster than others. It's definitely an effort worth making. I wish you strength, kindness, and good luck as you learn!",
"It's a skillset that you develop. It's being assertive when needed and knowing when to shut up. It's also owning up for your mistakes and the consequences it brings. Trying to understand things, but also being able to detach yourself when needed.",
"I often see this question in regards to relationships, so I'll put it this way: Maturity is taking care of the people you love. Emotional maturity is understanding that the people you love might not always take care of you.",
"It’s kind of like sharing your toy with someone that lost theirs. You didn’t have to share, and you only brought one. Choosing to share with them because you know it could help, is a sign of emotional maturity. *obvi a very eli5 example*",
"Emotional maturity is another way of saying you're capable of maintain your emotions in a healthy way (keep a level head, cry when you need to, scream in a pillow, etc.) and being aware of the impact it has on your relationships (talking it out vs. having a screaming match, maintaining empathy and boundaries, etc.) ... as well as understanding the capability of others to maintain their emotions and understanding the impact that their emotions have on yourself and others"
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nwz74u | How did armies before 1900 manage sewage waste without polluting their water supplies? | I'm assuming soldiers used to bury their poop or dump it in the river. But, would this not pollute their water supply? When it rained, the buried poop would also pollute water supplies. How did armies manage sewage to avoid polluting water or did they just risk disease? During sieges or camping where they stayed in one place for a long time, the waste must have built up. How was this waste managed and disposed off without polluting water supplies. | Other | explainlikeimfive | {
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"In short. They didn't. They just buried it. Desease was a huge problem for armies especially during sieges.",
"Latrines. They would dig long deep trenches and then fill them in again. The military was pretty aware of the problem of keeping sanitary.",
"\\ > When it rained, the buried poop would also pollute water supplies. Not to a significant degree if you just dig a deep enough hole. Dig a 2-meter deep hole and use half of it and then cover it up. The will be minimal water penetration and what was there will not migrate a lot. You should of course not do it just beside the water source. A deep trench latrine like that are still used you can find them US Army manuals that are in usage today [ URL_2 ]( URL_0 ) at 5-14 You should of course not do it just beside the water source. & #x200B; I would not say that it was done just that buried poop is an option that works. The problem in the past was not that they could not have done it but that they did not know that it was required. The germ theory of disease as we know it today is from the middle of the 19th century. So historically the majority of the dead in armies was from disease not combat. If you look at the US it is first in WWII that more soldiers died in combat than in disease. [ URL_1 ]( URL_1 ) So the answer in large is that managing sewage was a problem because it was known that it was a significant danger and it killed more than combat."
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"https://armypubs.army.mil/epubs/DR\\_pubs/DR\\_a/pdf/web/atp4\\_25x12.pdf"
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nwzth4 | Do you lose blood when you're on your period and make up for it afterwards, or do you make extra blood before you come on your period and your body just loses the extra blood? | Biology | explainlikeimfive | {
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"As others have pointed out a woman doesn't loose much blood during period. But even if they would, you are constantly losing and regaining blood, in fact red blood cells are the most fast produced cells in your body, which is also why they are often the first ones to stop working properly at an old age. Humans are capable of surviving an astonishing ammount of blood loss, as long as they consume the nutrients needed to make new blood and the blood loss is not too great.",
"Over a period of 28 days or s, the female body creates \"bedding\" inside the uterus for a fertilized egg to snuggle into. If no egg is fertilized then the body sheds the bed. That's the blood and other tissue matter that is \"lost\" during a monthly menstrual period. Then the body begins to make a new \"bed\" in case an egg is fertilized over the next 28 days.",
"People do not actually shed blood during their periods. The uterus builds up a lining in preparation for the fertilization of an egg. If that doesn’t happen, the lining breaks down and sheds, creating the menstrual “blood”. Edit - grammar"
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nwzxc3 | why can you pop a balloon filled with air with a lighter but not one filled with water? | Physics | explainlikeimfive | {
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"text": [
"When you heat the rubber of the balloon, it melts slightly and creates a weak point in the balloon, allowing it to pop easily. But when it's filled with water, the water absorbs the heat, preventing any damage to the balloon itself."
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nx0kky | why does it take "up to 10 days" to be removed from an email list if it is all electronic? | You'd think it be instant | Technology | explainlikeimfive | {
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"text": [
"It is often instant. If they say it may take up to 10 days, it could be for different reasons. More legitimate reasons might be that emails are scheduled to send ahead of time, and their system doesn't edit the list of recipients for scheduled emails when someone is removed. Less legitimate reasons might be because the page where you remove yourself from the list has intentionally tricky wording, so people often check a box that's actually indicating they want to stay on the list thinking it will do the opposite. If they believe it won't take effect immediately, they won't notice the problem at first and may forget about it entirely.",
"Mass email Campaigns are usually scheduled 1-2 weeks in advance and are essentially locked on their sending list when they are first generated. This is just how most mass mailing systems work. So when you unsubscribe, it will prevent you from going on any newly created emails, but ones that are already locked to go will not remove you.",
"It may not be all electronic. We keep our list manually. Both subscribe and unsubscribe requests are handled by a live human being who somehow needs to sleep, eat, take vacation etc. it is a small list and there are few requests (five a week maybe) so there is little value in automation. The manual system is also a nice way to ensure more “enthusiastic” colleagues don’t have easy access to the list."
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nx1gzd | How do prosthetic hands of amputees who were born without, or lost their hands know which finger to move? | Technology | explainlikeimfive | {
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"text": [
"It's two different cases. If you have a hand and lose it, you have all this neural hardware that no longer works. With the prosthetic it's a matter of transferring that structure to a new outlet. If you've never had one, then you have to build the ability from scratch. Either way, it's many weeks of difficult physical therapy, just like a baby learning to control its hand, lots and lots of reps are needed.",
"I'm over my head on this, but in a general sense the brain is plastic and universal enough to gradually make sense of new data. It was interesting to learn that the human brain can make sense of sonar or ultra violet rays if there was a peripheral device with a proper connection. It was originally thought that certain areas of the brain controlled certain peripherals. Yet research has shown that if a brain is damaged another part of the brain can learn to control the area. Again, I'm only relaying what I have read. I like your question.",
"Not really an answer, but I've seen a video of an experiment where they attached a 6th finger (it was a second thumb I think, on the other side of the hand) to peoples hands and taught them how to use it. Despite never having 6 fingers on any hand, people were quickly adapting to it and were even finding new applications for such an extension. I would assume it's the same for amputees, even those who never had a limb. Brain is an amazing thing man."
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nx1yoe | how does foam prevent/suppress fires exactly? | I recently was reading a bit about aircraft carriers in WWII, and something I read often is how when there's a fuel leak they were supposed to flood the hangar with foam. I also saw before systems in aircraft hangars and fuel stations that would flood the place with foam in case of a fuel leak. How exactly does this work? Usually fires are suppressed with water, or some other chemicals, what is it about foam that prevents fires? | Chemistry | explainlikeimfive | {
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"If you looked at the foam under a microscope what you would see is it looks kind of like a honeycomb in which large pockets of air are trapped in a web of very thin, non-flammable liquid. The non-flammable liquid component of the foam is forming a physical barrier that prevents oxygen from reaching the fuel underneath. At the same time, the foam itself is mostly air. Air is a really poor conductor of heat in general and essentially does not conduct heat at all if you can prevent convection from happening (basically, if you can prevent the hot air near the heat source from mixing in with fresh, cold air). The fact that the air in the foam is, well, trapped in there prevents convection. This means that foam is an exceptionally good insulator. To generate a fire you need fuel, heat, and oxygen. If there is a fuel spill then you now obviously have a fuel source. But if you smother that fuel underneath a layer of foam then you've prevented it from being exposed to heat or oxygen - either of which will prevent a fire. Finally, at least as to water - aviation fuel is lighter than water. If you spray water onto it the fuel just rises to the top and you really haven't accomplished much. If the fuel is already on fire then the water gets superheated as it \"sinks\" through the burning fuel. This causes it to instantly flash to steam which then expands outwards, creating a rapidly expanding bubble of burning fuel. This is also known as an explosion. Foam, on the other hand, is exceptionally light so it remains on top of the fuel. This is obviously more useful for preventing a fire in the first place and doesn't result in an explosion if you spray it onto fuel that is already on fire."
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nx2if8 | Whenever something’s spinning fast, why does it look like it stops for a moment then starts going in the opposite direction? | Physics | explainlikeimfive | {
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"text": [
"Shutter speed. If the item is spinning at a rate of 30rpms and the shutter of a camera is at 30 frames a sec. It will be like taking a picture of it standing still. Now if the rotating item slows or speeds up over that the shutter speed is then every time a pic is taken the item will be progressively rotating in a different spot giving that effect.",
"I believe it has to do with the frame rate of our eyes. If we see in 60 frames a second and the wheel is moving at a speed where the spokes line up in the same spot every time our eyes refresh, the wheel appears to have stopped"
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nx37e7 | the difference between steroids, TRT, testosterone/estrogen, etc. | Biology | explainlikeimfive | {
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"text": [
"Steroids are a group of hormones produced by starting from cholesterol. Chole**sterol**-oids, you could say. URL_0 They're classified into different groups depending on which receptors they activate. Progestagen, Corticosteroid, Estrogen, Androgen. Corticosteroids are used medically to make the immune system chillax, so for treating autoimmune or inflammatory diseases, allergies and similar. The other steroids are used to influence overall metabolism and especially reproductive function. They **definitely** have an impact on mood too but there has been a lot less research conducted on this topic than there should be. Testosterone replacement therapy is traditionally used to normalize unusually low testosterone in men caused by injury or chronic illness. There's a modern marketing push to \"replace\" declining testosterone with age. Drug regulators are *very* skeptical of this (you're not supposed to market a cure for anything without medical evidence) and the marketing is often illegal. So, grassroots it is. It's used for voluntary, not medically necessary, body modification by athletes. This is also a source of concern - or pearl-clutching - and is the biggest reason why androgens are controlled substances. And TRT is used to treat disorders of sex development and/or gender dysphoria. If your body doesn't make enough testosterone to keep your brain happy or to develop male secondary sex characteristics, adding more testosterone usually helps. Unfortunately this isn't as well studied as it should be, but the evidence that does exist supports the argument that TRT is effective and necessary for these conditions. Estrogen replacement therapy has a pretty similar picture but for women. The drop in estrogen with age is more significant for women, so there's better evidence that ERT is a good idea to reduce the risk of osteoporosis, but the overall picture isn't clear. (Is less risk of bone breaks worth the greater risk of breast cancer? And similar questions.) Hormonal birth control uses a progestagen and possibly an estrogen. And fertility-enhancing treatments can use steroids, though I'm not familiar with the details. It's all a fairly complex topic, so it's hard to know where to start."
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nx3jyk | how do preservatives in food work? | Chemistry | explainlikeimfive | {
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"text": [
"Preservatives are chemicals which slow down the growth things which cause food to spoil. These chemicals can be eaten by people without ill effect, although many people worry that consuming these extra chemicals can’t be good in the long run. Preservatives can be grouped into three general types: antimicrobials that block growth of bacteria, molds or yeasts; antioxidants that slow oxidation of fats and lipids that leads to rancidity, and a third type that fights enzymes that promote the natural ripening that occurs after fruits or vegetables are picked. An example of a chemical which does all three things is Sulfur dioxide, which is part of a larger group called sulfites, compounds found in numerous foods. Some people are sensitive to sulfites and try to avoid them, but most people don’t notice them in their food."
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nx3zed | Why is it when you get hit, it hurts and stops hurting shortly after, but after sleeping it hurta even more? | Biology | explainlikeimfive | {
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"text": [
"The initial pain is from the strike itself, which puts pressure on the neurons responsible for pain. When they're under pressure or damaged, they send a pain signal. But that pressure is short-lived, so the signal fades. The initial hit also damages cells in that area, and damaged cells emit a 'distress signal' of chemicals that cause inflammation. Inflammation causes extra fluid buildup and blood supply in the area, which makes it swell up, which again puts pressure on the neurons responsible for pain signals. But this buildup requires a series of chemical steps that take a little bit of time to happen."
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nx48ye | how does alcohol dehydrate a person? Is it through the actual act of drinking or that it makes you urinate more and you don’t replenish with water? | Biology | explainlikeimfive | {
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"Alcohol is an antidiuretic hormone inhibitor. There's this substance in your body that works to keep you from peeing out more of the water inside of you than is healthy, but alcohol gets in its way and interferes with its work, so when you drink, you pee too much. URL_0",
"Alcohol is a diuretic which causes your kidneys to pull more water from your body and produce more urine. If all you drink is alcoholic beverages you are not replacing the water you are losing, which can lead to dehydration and hangovers. Best advice, for every drink you have, drink a glass of water.",
"The other comments about alcohol being an antidiuretic hormone inhibitor are correct but a study I can't find atm found that upto 4% alcohol still hydrates you as the ~96% water you're drinking outweighs the keeping less water. And really you're only going to the loo more because you're often drinking a lot of liquid when out drinking.",
"There is a hormone called ADH that tells your kidneys to just filter water but keep some and send some to the bladder. Alcohol won't let it be produced by your brain so your kidneys just assume that there is too much water in your blood stream and send it all to your bladder. So you pee like you are well hydrated, while actually becoming dehydrated. The common term \"breaking the seal\" is really just the start of this cycle of your bladder not holding anything back."
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nx4vt0 | You know the feeling. You go to stand or walk and find that your pillowy pads AKA feet that typically support your weight and gait effortlessly, have morphed into tingling, sharp, unbearably painful pads that scream with every step you make. Why?!?! | Biology | explainlikeimfive | {
"a_id": [
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"text": [
"Its called paresthesia; or what most people call a limb falling asleep. You had your leg positioned in some way that it pinched the nerves leading to your foot. This disrupts how they communicate and it sends pain signals and other garbled sensations until it recovers"
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nx57dg | Why is it when you mix rainbow colors the result will always be brown? | Physics | explainlikeimfive | {
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"text": [
"Colors are light. Each color of the rainbow is a different wavelength. Other colors are made of combinations of the colors we see. White is every color at once and black is no colors at all. The other thing you need to know is that paints reflect some light (the color you see) and absorb the rest. This means as you mix colors you tend to absorb more colors and get closer to black as the mixture absorbs more colors and reflects less. Because our eyes absorb a few colors better than others (based on how the cells in our eyes work) the most common result of mixing is that we see a mix of the colors we see best (because we’re getting a random mix) and that leads to a brown color.",
"Pigments, like paints, are “subtractive” colors and when you combine them you get the effects of all the parts. Different pigments reflect different colors of light, something will appear red because it reflects the red portion of light and absorbs the other colors. The more different pigments you mix, the more colors are reflected, and it gets muddy and dark. When you mix light (like on a screen) its the opposite, “additive.” On screens, Red + green + blue = white! The natural light spectrum contains many more different shades (like a rainbow) but when they all are reflected together they also appear white."
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nx5z5b | why can’t you just fix a broken spinal cord by putting a conductive material in the severed area? | What im asking = neurons - conductive material ====———====== =====——====== =====——======= Etc. | Biology | explainlikeimfive | {
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"text": [
"Neurons are not passive conductive material - they dynamic, living cells that respond to their environment and are constantly changing their behavior.",
"Nerve signals are sent as an electro-chemical pulse within each nerve cell. Between nerve cells, it becomes a chemical signal. If a nerve pathway is broken, the electrically conductive material won't be able to transmit the chemical signals that are used to communicate between the nerve cells on either end of the break. Outside the scope of ELI5, the signal within a cell is electrochemical rather than purely electrical. Running a tiny wire through a nerve cell wouldn't help it work any better, because the signal is sent by a cascade of sodium ion pumps through the length of the cell, rather than a literal bolt of electricity. You can trigger the electrochemical cascade of a nerve cell by shocking it with electricity. This is one of the theoretical methods of fixing a severed nerve, have a microchip listen to the signals on one side of the break, then send electrical pulses to the other side of the break to stimulate the nerves manually.",
"Back in the day, when all the telephone lines were copper, you had giant cables with hundreds or thousands of wires in it, each going to a different house. If you cut the cable, and just glued it back together, most of the individual lines would either not get reconnected, or would get shorted out to its neighbor. You'd have to reconnect each individual wire, and on top of that make sure the each wire on one side goes to the specific wire it's supposed to on the other. A spinal cord is similar, except all the individual wires are microscopic, and unfortunately they are neither labeled nor color coded."
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nx5zia | If our natural body temperature is 96°, why do we feel most comfortable in 70° temperatures? | Biology | explainlikeimfive | {
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"Our bodies produce a good amount of excess heat and need to get rid of it. We get rid of heat faster in cooler temperatures. It varies from person to person but a 'comfortable temperature' is generally right around where your body is able to get rid of that excess heat at the same rate that your body is producing it. This is one of the reasons when exercising cooler temperatures feel more comfortable and when doing nothing and your body is idle, warmer temperatures feel more comfortable.",
"Because 70 degrees is the ideal temperature for the human body to perform all the functions necessary to maintain homeostasis. No part of us is havinh to work harder or be suppressed, all bodily functions occur at an ideal level at about 70 degrees. Edit: This is because the human body generates heat, thus a temperature matching that of the human body would need to be cooled, hence sweating, heavy breathing, etc.",
"That’s inside of you. Your skin and limbs are usually colder than this. And it’s the ideal temperature for the body to do its work, but that work generates a lot of heat, which it needs to evacuate. When it’s as hot outside as it is in, getting rid of this excess heat becomes harder, and you feel hot."
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nx6fm7 | why is ‘colonel’ pronounced so differently from how it’s spelled? | Other | explainlikeimfive | {
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"The word \"colonel\" entered the English language in the 16th century from the French word, coronelle, which itself came from the Italian word colonnello, which in turn came from the Latin word columnella, meaning a column of soldiers; so a coronelle was the commander of a column of soldiers. The French adapted the pronunciation of word and changed the \"l\" to an \"r\" making colonello into coronel. In time, the English shortened the pronunciation of the word from 3 syllables to 2, going from \"co-ron-el\" to \"ker-nel\", but never changed the \"l\" to \"r\" when written, so spoken, it's ker-nel, but on paper, it's still colonel.",
"English borrowed it from the French word ‘coronel’. The French had borrowed that from the Italian word ‘colonello’. Due to the process of dissimilation, the French has changed the “l” to an “r”. Eventually the spelling was standardized to ‘colonel’ in English, taking from the original Italian word, but the pronunciation stayed the same."
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nx6hy9 | Why does bleach make so many different materials of different chemical compositions lighter even though it presumably interacts with them in distinct ways? | I don't understand how the chemical bleach has the same effect on my navy blue t-shirt as it does on tree bark as it does on red vinyl. Are some chemical properties so simply universal? | Chemistry | explainlikeimfive | {
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"No, it interacts with them all in the same way, depending on the bleach. What bleach generally does is to oxidize (for chlorine based bleaches) or reduce (sulphur dioxide) the chemical bonds of the pigments in whatever you put it on, which has the effect of removing the colour from them. This is the same thing that high-energy photons in sunlight does, but it obviously happens much faster.",
"Ordinary organic chemical bonds (‘single bonds’) don’t absorb visible light. Some wavelengths of visible light are absorbed by dyes containing an assortment of double and triple bonds. Those double and triple bonds are easily degraded by the chemical in bleach, changing from double or triple bonds back down to single bonds. Changing those bonds changes the dyes ability to absorb light thus changing its color. Oftentimes the change is such that the degraded dye no longer absorbs visible light at all. Also, inorganic dyes like rust don’t have the same type of double/triple bonds that normal dyes do, so bleach is much less effective on them."
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nx7h02 | How does headphone impedance work? Are harder to drive headphones objectively better? | A lot of premium headphones require a lot of amplification to be heard, and I don't get why that's the case when many other headphones sound great even though they have low impedance and can be driven by something like a phone. | Technology | explainlikeimfive | {
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"High impedance headphones were designed for recording studios where a bunch of people would have their headphones plugged into one source. The headphones were designed with high impedance so it wouldn't overload the amplifiers. Because they were designed for recording studios they were by nature higher quality. Audiophiles started using them for home use because they were higher quality. There really isn't any reason why low impedance headphones can't match the quality of a high impedance headphone.",
"\"Hard to drive\" does not really describe the role of impedance accurately. What impedance says is \"how much of the power is in the voltage, how much is in the current\". Low impedance means you can drive a lot of power with relatively small voltages, which is why low-impedance headphones work more readily with the audio outputs in computers and portable devices, which rarely deal with voltages higher than 5 volts, and frequently less than that (yes, computers have +12V lines, but they are used mostly for motors and to convert to voltages of less than 3.3V in VRMs), whereas high-impedance headphones need a specialized amplifier that can do higher voltages to get appreciable levels. Since cables are in series, any power lost in the cable is proportional to the current squared, so high-current loads are more likely to need beefy, low-loss cables. That is why even low-impedance headphones tend to have a higher impedance (usually along the lines of 32 ohms) compared to 4-ohm or 8-ohm speakers. You can use beefy wires for the speakers, but with headphones, wire weight may be a concern for usability, so it makes sense to shift the load more towards voltage; especially if you are using a headphone amplifier - if not, you are limited by the source's max voltage again. Finally, the impedance of no headphones being connected is essentially infinite. Most amps control voltage, so the higher the impedance (and the lower the current draw, accordingly), the less the headphones can interfere with the amplifier's behavior, which is important in the situations /u/empty_coffeepot mentioned."
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nx9yrt | Why does our anus have receptors for spicy stuff? | Biology | explainlikeimfive | {
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"The TRPV1 is the receptor that capsaicin (spicy) binds to. It exists all over your digestive tract and nervous system. Your rectum and anus are included in this. These receptors are designed to detect “heat” to keep you safe. But they can get confused with foods that taste “hot.” They cause a reaction to cool you down, and you have a response that says, “No, this is dangerous.” So you sweat, and blood flow increases, causing redness. These receptors exist in all of your digestive tract, which is why you may experience stomach pains or some cramps after eating this. Not all of it digested and so the response is activated again at the anus.",
"Its just heat receptors but the skin around the anus is not skin, its membrane, it absorbs chemicals easily, the remaining spice is absorbed and the capsaicin does its trick, fooling you into thinking its hot when its not. If anything i can feel spice in my intestines as its very uncomfortable and i get diarrhea from it.",
"There is no specific receptor for \"spicy stuff\". At least that is not the intended purpose of it. The nerve endings that get activated by the capsaicin molecule are the same that transmit signals about heat/pain. So as long as there are those nerve endings, and they can be hit by the molecule, which works best on mucosa, then you can feel the spicy stuff. As for the reason why those nerve endings in the anus exist in the first place, this is more difficult to answer. I do not agree with the other answer that it does not serve any purpose. But I must admit that I can not see an obvious one either. It may just be for protection. This is the main reason why pain receptors exist. So damage is avoided.",
"It's not just your anus - it's your entire skin too. And this receptor isn't really for detecting spicy stuff - it's actually to detect heat (i.e. high temperature). Your skin has heat receptors to prevent damage, so that you can quickly move away from something hot (e.g. pull away your hand) before it burns you (too badly). For some reason, these heat receptors (at least some of them) are also chemically sensitive to a molecule that's present in spicy foods like chili peppers (specifically the *capsaicin* molecule). So the reason the anus has these receptors is because your entire skin has them. Only, your anus isn't protected by an outer, tougher layer, like say the skin on your arms, and so your anus is generally more sensitive. But if you rub a hot chili pepper on your arm you'll feel it burning too. In addition to being more sensitive, the reason the anus may stand out as \"uniquely\" sensitive to spicy food (or the remains thereof) is that these receptors don't exist in your intestines. So you don't feel that extra spicy Thai Curry going through your guts, but only when you poop it out as it suddenly hits those pesky receptors again, making it seem like your anus is the culprit, when arguably it's more the absence of these receptors in your gut that is causing this surprising sensation (basically, just be happy it doesn't burn the whole time)."
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nxakb8 | What exactly happens when a WiFi router stops working and needs to be restarted to give you internet connection again? | Technology | explainlikeimfive | {
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"Routers are essentially tiny, low-power computers. They have their own operating system in there and everything. When the OS is first started, it's in a 'clean' state where everything is configured and working properly. All the services are in place, all the connections are set up, everything is green. As the OS works, over time it might encounter problems. There might be errors. Some of those can be easily recovered from, some not. Some of them don't cause any problems, some of them interfere with the router's function, slowing it down or outright preventing it from doing its thing. Restarting the router returns the OS to that initial clean state where everything is working again.",
"It’s been a few years since a tech friend explained it to me. Iirc, he said something like when you power off/ unplug the device (most devices that use computer chips for that matter), it ‘drops’ everything it was doing. Essentially all the electrical signals flying around cease to be; including the ones responsible for whatever corruption is occurring. When you power on/ plug in, it’s like a hard reset. Again, it’s been a few years since and I’m certain there are much more knowledgeable folks lurking who will be happy to correct me but that’s the gist of what my non-tech-savvy brain could retain.",
"Answer: Imagine a router to be like a post office. And data like the mail going through it. One day, a particular large/deformed/mispositioned mail got stuck on the conveyor belt and blocks the entire operation of things from going on. And the post office has no idea how to take that mail out of the queue. So everything gets stuck. Restarting the router is like clearing out the entire room, people, mail and everything, and running a super strong air blower to poof every mail, stuck or not, out of the post office. Then the people come back in to work and mail het processed again without a care of whatever happened before the restart.",
"Long time embedded software engineer in telecom here. As many have discussed, these routers will have a small computer inside them. Actually, many have two or three separate computers, for example a CPU for the cable mode, a CPU for the Wi-Fi, and a CPU for the overall router function. If \\*any\\* of these CPUs get into a snit, the overall function can fail. Also the CPUs talk to each other, and if the communication between the CPUs (that you can't see) fails, then the device function will fail. Most of these CPUs will be running Linux, but some will run obscure operating systems you've never heard of. None of them are running Windows. The most common issue is just plain buggy software. Even if we are talking about Linux, it may be using a very old kernel, old libraries, obscure libraries, etc. The manufacturers go cheap on these things, and once it \"works\" there is a tendency never to upgrade anything again. One more issue can be chipset compatibility between the router's Wi-Fi radio and the clients. This is especially bad for brand new versions of the standard (Wi-Fi 6) but can happen on older versions too. So the problem here is just too many cheaply made moving parts. You have multiple CPUs talking to each other, one of the CPUs talking to your ISP, one of the CPUs controlling the Wi-Fi radio hardware ... and everything potentially running an ancient unsupported version of Linux. This is why most pros in the industry don't use these low cost integrated devices at all but instead use a solution like Ubiquiti Unifi. (Which has its own set of problems, see r/Unifi). One more thing: there is lots of discussion of accumulated Wi-Fi errors (FEC errors). I am not aware of any process where accumulated FEC errors would lead to failure. Wi-Fi is designed to gracefully handle stations drifting in and out of range or hanging around on the fringe, this in itself shouldn't be an issue.",
"One issue is down to memory leaks. When you write some program, such as the OS on a router, it needs to keep track of info (variables) such as a list of IP Addresses, list of connections etc. Each of those variables need to take up space in memory. & #x200B; What should happen is that when a variable is no longer required it is removed from memory thus freeing up memory to be used for other variables. The problem is if the program is poorly coded or has a bug then sometimes things don't always end up getting cleaned up and over time you run out of memory - either causing some sort of crash or making things run very slow. Restarting the device will clear the memory completely and remove all the junk in there.. **ELI5:** Memory is like a jar you add marbles (data to be stored) to. What should happen is any marbles (data) no longer needed are removed but this doesn't always happen and eventually the jar overflows (crashes) and the only solution is to completely empty the jar by restarting your router.",
"The real reason why you have to restart a router is that no-one from the designer to the knowledgeable friend who can help you troubleshoot issues want to spend any time on the thousands of issues which might be the root cause of your error, when a very quick and simple fix is \"restart the router\". It's easy, it's quick, it gets the job done. All the reasons given in other answers are just possibilities in a sea of possibilities. A router is a cheap computer, it has all the bug potential of a computer with all the fragility associated with cheap hardware.",
"For me it was NAT table overloading from trying to connect to too many P2P peers on a crappy modem, spent some money on a decent one and haven’t restarted in over a year",
"ELI5: Start counting at 1 and don’t stop. Keep going past 1000. 10,000. 1,000,000. Now pretend you lost count eventually. You don’t know where you were, so you have to start over. A router does the same thing, only it keeps trying to remember where it lost count, so you have to restart it to tell it to start at the beginning again.",
"Someone has written bad software. Restarting the router causes the shitty software to restart and will then run again for a while. If you buy a good router/modem it will not need to be restarted until it breaks. Here you can see the uptime of my router. And it's not 1 year 2 months because I had to restart it. It's 1 year 2 months because I moved apartments. URL_0 // Master of Engineering Computer Science ( I have distanced myself from scientific language and nowadays instead go with the word \"shitty\" a lot)",
"There can be many reasons for why a wifi router stops working. It can be due to a sudden change in the power current, it can be due to overheating and it can be due to random faults or bugs. Basically restarting a router makes it stop whatever it's doing, take a step back and try again from the beginning.",
"Many WiFi routers are underspec. The piddling couple megs of ram, and the same chip from 20 years ago running brand new software. In one case, the power supply died due to brownout. Couldn't power the transmitter. In another case, I think the chip couldn't handle the overhead of a firewall, and spontaneously died",
"Pay attention to those that tell you that it's cleaning cache, flushing stuff such as DHCP leases, etc., maybe even cooling a little. But the horrible, eldritch and cosmic truth is that the great ones are running their tentacle-ish fingers through your house, in another dimension, disrupting the signal. Because those little bastards, no matter when, where, how or how expensive they are, sooner or later they will fail. PS: Use CAT6 cable. It is Cthulhu-proof.",
"The router has sort of handshake protocols between the isp site and your PC. Sometimes one side has a glitch and is left hanging. Power of closes all protocols and restarts new ones. Hope that is simple enough.",
"Software dev here, but here's how I understand it. Imagine you're having trouble trying to understand a problem in an exam or on a project. Is it not better to take a step back and start again rather than going round in endleas circles and crash your brain?",
"More often than not its a cache issue, basically your router has a pretty shitty little brain that fills up quick, sometimes it's hummdrumming along, and a request comes from a device and your router goes \"um, I'm sorry... What??\" turn off turn back on and your router is all like \"oh yeah, I was routing... Silly me\" Other times it's a dns resolver issue where you're actually connected but for some reason your router can't find the dude he usually asks for directions on the Web, and just sort of gives up. A thousand moving parts, a thousand reasons why.",
"the modem is usually what needs to be reset, when you have a mis-configured connection the easiest way to get it resolved is to unplug it for then plug it back in. this will allow the modem to restart its setup and perform all the checks that it needs to make sure you have upload and download functioning properly. the modem will send and receive some data packets to perform these tests and it will check the data for errors as well. if all is well it should successfully allow you to use the internet on your computer once again. & #x200B; If the internet was open to anyone with a modem device, a lot of these checks would be skipped because a lot of these checks have to do with whether or not the address is a paying customer or not. if you no longer have service and try to hook up your modem, it will simply reject all your attempts to connect.",
"The software running on routers often needs to store some information in memory to work. Might be a package of information coming in through the internet. Sometimes the program doesn't really know beforehand how much memory it will need to do that, e.g. this might depend on some dynamic input. So the software needs to find some free chunk of memory in it's hardware where this information fits, this is called dynamic memory allocation. Now what sometimes happens is that programmers forget to free that memory again. Even though it's actually not needed anymore, it's task is done, the program forgot to tell the system allocating the memory that this chunk is not needed anymore. If this happens often enough (e.g. after the router has been running for a few weeks) there won't be any more free memory in the hardware. So when the system tries to allocate some chunk of memory it needs it can't, there is no free, unused chunk left in the hardware anymore. It's all taken up by some old data which is technically not needed anymore, however was never cleaned up. So the router can't allocate the memory it needs to perform it's function, so it basically hangs or stops working. Now the memory we are talking about is not persistent, it's cleared after power off. This is fine, the router doesn't (and shouldn't) remember old internet packages. So restarting the router resets the system to a known state and clears up all the unused garbage. The same can also happen with computers or smartphones. The only difference there is that every Programm there has its own chunk of memory, so you only need to close the program, not restart the whole device.",
"ISP tech here. Important note- router and modem are two different concepts. Most isp will provide you a gateway, usually including both those and an emta(landline service). A modem is the decoder, a \"(mo)dular (dem)odulator\" which translates rf, light, dsl broadband whatever you want from binary(just the raw signal being turned from 0 and 1 into usable data packets.) The router is kind of more like the brains or controller of your network. The router assigns local ips to your devices in the home as you only have one actual ip address through the modem. Meaning the router is what let's you hook up both the Amazon alexa, smart TV, and Xbox at once. A modem would only let you have 1 thing because it doesn't route traffic- only blasts it out at full speed. Heres the eli5 on that: Think of a water irrigation system for sprinklers. The conduit in which the water comes from is the modem, and all the pipes leading to individual sprinkles are the router. Only this time its wireless water. So as for your question- why do modems and routers time out? Well it gets tricky and tbh I don't think any of this is simple enough for an eli5 but here goes. When your internet service cuts out its either the router or the modem. But 99/100 times its a service issue with the modem. With fiber to coaxial (copper antennae) the field which im most familiar with, there are 2 important signals types, your transmit (up) and recieve(down). Normally when a modem \"times out\" meaning going down and no longer demodulating, its because somehow the transmit was affected. This transmit can also be measured in the time It takes for the modem to communicate back with a central hub system, cmts is what we call it. When your transmit is too high, which is worse than low(exclusions apply), and takes too long to communicate back you can get a timeout. There are also multiple transmit carriers, and while the modem can function on just one, it usually comes with a plethora of issues. On a side note, the downstream is your raw bandwidth capability and brevity of it. Here the best eli5, and if anyone's interested for more pm me- Think of it like the CMTS, central hub, is at the end of a long highway. And the modem is one of the many cars on the highway. Lets say this highway has 4 lanes(your transmit carriers). Lets say traffic is bumper to bumper but everyone is going the same speed lets say 50km/ph. Everytime a lane of traffic is blocked off, or closed, (your carriers being impaired or unusable) all the traffic in that lane has to squeeze into other lanes, therefore slowing everyone down, and some people get run off the road. If the car takes to long to reach the central hub, it says I can't wait anymore, and sends it back to the start. When you restart your modem you are effectively unjamming the traffic and putting your car back on the road, but if a physical cable impairment still exists the lanes will still be blocked off. Maybe your car doesn't get run off the road this time, and makes it to the end, but its not guaranteed."
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nxbu4g | Why can air be compressed but liquids can’t? | Physics | explainlikeimfive | {
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"Liquids can be compressed, but significantly less than air (and all gases) can be compressed. It’s to do with the molecule structure. Compression forces molecules close together. In a solid, all these molecules are tightly packed together. So you can’t really compress, because there’s no room. In a liquid, there’s a bit more room, so you can compress it a little bit. Gases on the other hand have a lot more area to move around, and so you can compress them a lot more than liquids.",
"Liquid can and does compress, but water is particularly bad at it because it's a highly polar molecule. Gasses are more compressible, in general, because the moleculed within them have greater degrees of freedom. Imagine trying to tell a group of people to squish together. Gas is like having a room with 10 people in it and telling them to get closer. Liquids are like having the same size room with 100 people in it and telling them to get closer. Water is like having the same size room with 100 people, but none of them use deodorant and they all hate each other. And since we're on the subject, solids are like the same size room with anywhere from 100-1,000 people but they all have to stand in a certain place and if you make them squish the room breaks and the people fly off in different directions.",
"Because there's a lot of empty space between air molecules (or gas molecules in general) but almost no space between liquid molecules. If you actually force liquid molecules any closer they'll start to form latice bonds and the liquid will freeze into a solid",
"It's about the same as crumpling a piece of paper. The more compact you go, the harder it gets. To the point where it may seem that you can't compact it anymore. It's compact enough for you to stand on it, even though it's still possible to get it more compact, to your perception it can't be compacted anymore. So both gasses and liquids can be compressed, they just require a different amount of force."
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nxbw2l | Why do your teeth feel gritty after throwing up? | Biology | explainlikeimfive | {
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"When you throw up, you're throwing up what's in your stomach. In there, there's stomach acid which your body used to digest. Your teeth however are not immune to that acid, so as you puke, the acid attacks the teeth. It's similar with cola."
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nxceb0 | How is excercise good for your heart, aren't you just putting it under stress? | Biology | explainlikeimfive | {
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"The heart is a muscle. When you train the muscle (take A HIIT class) it works harder, thereby getting stronger. If you did the same workout at the same intensity every day, over time your heart wouldn't have to work so hard because it's been getting stronger.",
"It is all about conditioning your body to be able to it for longer, like anything else in your body you can promote it to be stronger and healthier",
"Every time you exercise, your muscles wear out and weaken. Then when we rest, they repair that damage and grow bigger as a buffer so that next time, they don't get damaged as much. Your heart is just like any other muscle and does this too."
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nxejja | How did money become as important as it today? | Other | explainlikeimfive | {
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"Commerce. Trading x for y. If you’re the best fisherman in the world but don’t know how to light a fire and cook a meal how would you pay for it or the knowledge to do so?",
"Economy... you can get anything in the world with enough money. You make a living depending on your money. If you have no money, you have no home, no food, nothing. In today’s day in age, money decides your status, as your lifestyle is depend any on it."
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nxf560 | Where do internet providers get the internet they're providing? | Technology | explainlikeimfive | {
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"The internet is a communication network, not a substance. I blame all the silly water analogies for making a lot of people thinking this. They don't get the internet anywhere, the collective interconnected ISPs and the computers connected to their networks *is* the internet.",
"Most people will connect through an ISP who is a Tier 3 provider. Tier 3 providers are buying capacity off of Tier 2 (for local) and Tier 1 (for international) providers. They can run there own data center which will include the hosting for their email servers and websites but many ISPs are outsourcing even that nowadays. Tier 2 networks will have peering (i.e. free) or interconnect (i.e. cross payments) agreements with other networks within the country to provide access to what is essentially the local internet. Tier 1 networks will interface with the international data cables. So essentially if you are setting up an ISP you need to have an agreement with a telecom provider to supply the last mile access to the client, agreement with a Tier 2 network for local bandwidth and Tier 1 for international.",
"It's more like, the internet is water, flowing between ponds and lakes and oceans along rivers, and the internet service provider is the company that builds the pipes to deliver that water to your house and pump sewage water out. In more technical terms, the \"Internet\" is just a bunch of computers storing data around the world and they are connected via cables and radio signals and the internet service provider is adding a line that connects you into that.",
"They put a bunch of computers in a room and connect them together. Then they connect their computer room to other computer rooms in different places. That allows them all to talk to each other so you can access information regardless of which computer room its stored in."
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nxfcmn | If Force = Mass x Acceleration, why do things still have force when not accelerating? | I’ve never understood. To me, Mass x Relative Velocity makes more sense. Can Anyone explain why it’s worded that way? EDIT: Thank you for the answers. I was confusing Force with energy and momentum! And I clearly have misunderstandings of the fundamentals of acceleration. | Physics | explainlikeimfive | {
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"it is because you're probably confusing force and energy/momentum. example, you play golf or something like that. the ball is resting, then you hit it, exerting a certain amount of force onto it for a really really brief moment. this accelerates the ball from speed \"0\" to speed \"fast\". after you hit it there's no force working on the ball (well besides air resistance and gravity), so it's not accelerating any more but now has a constant speed. if your golf ball now hits a glass window, then it will again exert a force onto that glass window (most likely shattering it), decelerating the ball. what you're doing is transfering energy/momentum from your club to the ball to the glass window. this is probably what you had in mind when you said \"it has force\".",
"When you state Newton's second law F=ma, the F is the sum of all force. For example, a stationary object is subjected to gravity (downward) and a normal force by the ground (upward). The sum of the forces is 0 here since they have opposite direction and equal magnitude. Hence, the acceleration is 0.",
"F = m*a is about the force F needed to give an object with mass m an acceleration a. Like, how hard you'd have to push to get something moving (or slow it down). Sounds like you might have this mixed up with kinetic energy?",
"Things don't produce a force when they are at constant speed. Or at least all forces cancel out. A meteor going at a constant speed has lots of stored momentum,but produces no force. When it crashes into a planet the momentum is transfered into a force acting on the planet. The force is relative to the mass of the meteor and how fast is it slowing down (acceleration).",
"Your definition is momentum, which is different than force. Let's start with Newton's 1st Law - an object in motion stays in motion *unless it's acted upon by an outside force*. Let's reverse the phrasing of the law - \"An outside force causes a change in motion of an object\" The definition of Force therefore implies that a force *changes the motion* of the object it interacts with. Change of motion is literally defined as acceleration, and the mass is the scaler, the more mass the more force you need to apply.",
"I think you're confusing force with momentum. An object moving at a static speed doesn't really have force, or at least a minimal amount (the amount necessary to keep it from stopping). When it *hits* another object, its rate of acceleration changes and it applies force to the other object by accelerating it. Momentum is a measure of motion of a moving body, calculated with mass x velocity (not the same as acceleration). So an object in static motion has momentum, but would only apply force to something it is in contact with. As stated by another, friction will decelerate objects, so force could be calculated using the necessary acceleration to constantly overcome friction...but in a frictionless environment all you would have at a static speed is momentum, not force (until it collides with another object)."
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nxfscg | How do our eyes "lock on" to objects, keeping them in constant focus despite movement, to the point where un-focusing takes conscious effort? | Biology | explainlikeimfive | {
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"Our evolutionary needs required us to be able to narrowly focus on specific objects at specific distances, be it a branch we're jumping to grab, a predator hiding in the bushes, or a prey animal we're hunting. We developed the ability to control our eyes independent of our head (birds, for example, lack this and move their heads to see, not their eyes). Our forward facing eyes increase the overlap of vision from each eye and are adapted to increase depth perception, to better understand distance and relative motion of the things we're focusing on. We have the ability to change the shape of the lens in our eyes which adjusts the beam of light we're \"seeing\", allowing us to track the image and keep in focus. In short, our ancestors who lacked this focusing abilities missed the branch they were swinging for, didn't see the tiger in the grass, and didn't kill the food they needed to survive.",
"Two things: 1. Our eyes are (arguably) a part of our brains. They’re the only visible part of our brains. The retina is made of brain tissue, and the whole structure grows out of the brain during embryonic development. I’m only saying this to highlight how close the mechanisms of the eyes (which receive external stimuli) is to the mechanisms of the brain (which process this stimuli) 2. Many different parts of the brain have the function of processing visual stimuli. The occipital lobe (back of ur head) is the most important part in this respect, whose main job is to processes visual info, and so it has many specialised functions related to it. Functions such as color differentiation and motion perception. So if ur looking at something in motion, parts of ur occipital brain is lighting up, because ur eyes are noticing differences in light, and ur brain is processing such differences as “movement.” This whole process - 1. eye receives stimuli, - 2. Sends visual info to the brain 3. The back of ur brain (occipital) processes this info - is automatic, just like differentiating red from blue is an automatic process. Therefore, keeping track of something in motion is less difficult than trying to not keep track of the same thing, because the first is automatic, the latter is conscious. Hope this helps, let me know if u have any further qs!"
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nxfu0h | How can wine have so many distinctive flavors despite being made only from grapes? For example I recently had Sauvignon Blanc that had a distinct taste of Green pepper, yet only grapes went into making it | Chemistry | explainlikeimfive | {
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"A number of causes, including: 1. Differences between grape varieties. Sauvignon Blanc is the name of a white/green grape variety, as is e.g. Chardonnay or Riesling. Red grape varieties include merlot, pinot noir and shiraz/syrah. Each of these grape varieties has different characteristics and a different flavor profile. Wines may use a single grape variety or a mixture, and so by choosing their grapes wine makers can influence the flavor profile of their product. 2. Differences in the wine's *terroir -* a fancy word from French that literally means \"land\", which refers to properties of the soil (e.g. mineral content) and often more broadly also properties of the environment (e.g. humidity, temperature, sun exposure, etc.). The mineral concentrations in the soil will be reflected in the grapes, for instance, and the amount of sun has an effect on the sugar content. 3. Differences in the wine-making process, of which there are many. Did they filter the wine? What yeast(s) did they use? Did all the grape sugar get fermented into alcohol, or did they leave some residual sugar in the wine (giving a sweeter flavor)? How was the wine bottled or aged? Did it spend time in wooden casks (with the wood imparting its own flavor), or was it kept in metal or otherwise flavor-neutral vessels? Basically every step of the wine-making process can be altered to produce (slightly) different results. Fermentation is also key here. You start with ingredients that are already have variation between grape varieties & terroir, but then what the yeast does with that afterwards and all the flavorful compounds that yeasts can produce, creates a whole explosion of additional possibilities. If you just made grape juice you would also taste some differences depending on grape variety and terroir, but the variety of flavor profiles you get wouldn't be nearly as large as the variety of wines that results from fermenting those grapes with different yeasts and through different processes.",
"Grapes have several different acids in them: tartaric, citric, malic, lactic, succinic, and acetic. Those acids react with ethyl alcohol and form esters. These esters are responsible for much of the fruity flavors of wine that are not grape flavors. So that's why you can taste and smell blueberries, strawberries, lychee etc. from wine made just from grapes. Now the green pepper aroma/taste comes from a class of chemicals called pyrazines. Some grape varietals have a natural propensity to express those but also it can be influenced by too much water or not trimming enough of the leaves off the vines.",
"Edit:I have no idea what category to put this into, buta I'm thinking its related to organic chemistry somehow"
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nxgvpv | Why do drinks have so much sugar and why is that drinkable while just a few grams of sugar you add yourself so much sweeter? | Edit: Missed the word "is" in the title. A teaspoon of sugar is about 4 grams. That small amount of sugar added to a drink as bitter as coffee makes it almost too sweet to drink and 8 grams makes it undrinkable for me entirely. So 8 grams of sugar in coffee makes it too sweet to drink, but a Mt dew, which is drinkable for me, has a whopping 30 grams of sugar in 8 ounces compared to the 4 max I would put in my coffee. *I'm bad at math and I'm waking up so I'll show my work (257g of sugar per 2 liters, about 68 oz in a 2 litter, 257/68 gave me 3.78g of sugar per fluid ounce X 8oz is 30.25 grams) please let me know if my early morning barelycaffinated brain messed that up.* It's not just pop either. Bottled juice and sports drinks have an absurd amount of sugar as well. The hell is wrong with these beverages that they need such a ridiculous amount of sugar and why is 30 grams in 8 ounces of Mt dew tasty, but 8 grams in coffee undrinkable? Why does it seem like your only options are to drink something that has enough sugar to kill a horse or none at all. There doesn't seem to be any middle ground. | Chemistry | explainlikeimfive | {
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"Aside from type of sugar, there's also the acid/salt content of the food. For example, soda contains plenty of acid in the form of citric acid and carbonic acid. If you drank a soda with zero sweetener, you would be shocked and horrified at how acidic it tastes. Add sugar and you start achieving a balance that eventually tastes good. Opposite is also true. A soda with no acid (but regular sugar content) will taste shockingly sweet and undrinkable. Add in plenty of acid (sourness) and we achieve a balance. This is true for many salty foods too. Many processed foods have so much salt they are basically inedible without sugar added."
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nxh903 | Solar eclipses will occur on new moon days. Why solar eclipses do not occur on every new moon day ? | Physics | explainlikeimfive | {
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"Because the Moon's orbit is slightly inclined relative to Earth's orbit, which makes it not pass directly between the Earth and the Sun on most of its orbits. You can see an interactive demo of it [here]( URL_0 )"
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nxh9kl | When a game's "code is lost" what stops a company from dumping/decompiling code from a disk or cartridge copy of the game for things like remakes and remasters? | Technology | explainlikeimfive | {
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"Decompiling isn’t all that easy, and if it works at all you’re left with bare code that contains no notes about how anything is supposed to work. Millions of lines of code that someone wrote years ago with no explanation about what they do or why. While it’s theoretically possible to reverse engineer a program that way, it is much too time consuming to be practical for a product you’re trying to make money on.",
"They absolutely can. However 99/100 times it's a pain in the neck and more effort than rewriting the thing from scratch. Code is written by humans for humans. It has nice human structures that make sense, it is organized in to well named files in neat logical folders, it has descriptive variable names, it hopefully has a bunch of comments so that developers can communicate with both each other and their future selves, functions have clear markings what they are intended to do, all that nice stuff. The computer doesn't care: it neither needs, understands, nor wants any of that. In the process of compiling the code from human-code to machine-code the compiler will discard anything that it believes isn't useful to the final product. Comments are thrown out, file structures pressed to single files, variable names replaced with shorter pointers, all of the human element vanishes. Decompilers can't bring any of that back. They don't know what the compiler threw away and have no way of recreating it. What it will do is create its best approximation of \"human-readable\" code that does the same thing as the original code. However it will still have all of that awkward computer-preferred structure and meaningless variable and function names. Working with the de-compiled code as a human is extremely tedious and you'll need to put in a lot of work just understanding what each section of the code is meant to be doing. And remember we're talking hundreds of thousands of lines of code: Libraries worth of nonsense. At some point it's better just to give up and do it again from scratch.",
"Software developer here, former game developer (not that it matters), Compilation is a one-way transform. Take, for example: bool less_than_seven(int x) { return x < 7; } This is code, a text document written for humans, by humans, and only incidentally for computers to possibly compile and execute. Computers don't need to know what a `bool` data type is, it doesn't need to know that this is a function, and specifically, it doesn't need to know that it's named `less_than_seven`. It doesn't need to know the variable is called `x`. It probably doesn't even need the variable. It very likely doesn't care that we're doing a ` < ` comparison. All this information can and likely will be lost when translating to machine instructions. You can't search an executable program for `less_than_seven`. That information is gone. This code, this function, very likely won't even generate machine instructions for a function call - the compiler might determine the cost of pushing and popping the call stack is more expensive than just performing the comparison in-place where this code is used elsewhere in the source. In place of a variable stored in memory, the compiler will probably store the value in a register. The compiler might even deduce that there are more clever tricks, faster instructions to use than the built-in less-than compare instruction; the program will produce the same result, but it won't be intuitive. So gone is all the context - function names, variable names, variables, and data types; gone is the intent as it was expressed for humans in the source code. There are tools to decompile executable code, but it's tricky at best for other technical reasons. And of course, the tools don't know what it's decompiling. So how does it know that some particular piece of memory stores hit points, or bullet counts? All the tool is going to do is deduce what might probably be a variable, and call it `variable_1234_`, and that's all you're going to get. And typically, these tools CANNOT produce reversible code - that is to say, what they generate won't compile again back into the same binary from which it was deduced. The best you can do is reverse-engineer an approximation of what the original source code might have been. And I emphasize *approximation*, because it won't be exact, and it won't be correct, and it won't be a faithful reproduction. It is incredibly challenging.",
"With all the optimizations and obfuscations done by modern compilers, the process of compiling software is generally a one-way trip. When you lose a game's source code, you don't just lose the thing that makes the engine work: you often also lose the most important source of documentation and insight as to how it was intended to work. Automated \"decompilers\" exist, but they can't actually reproduce the original source code: they can port the machine code to a higher-level language, but this generally bears very little resemblance to the original source. That's not to say that it's useless -it can be an important reference tool as you rewrite the program- but in the end you're still rewriting the program from scratch."
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nxhctx | Why do songs get stuck in head even if we want to forget it? At times i sleep with a song stuck and wake up with same song playing in head the moment I get up. Why does this happen? | Biology | explainlikeimfive | {
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"Does the song play as if its really playing and you fan here every note of the song as if it's playing? Could be you have a disorder like bipolar/ADHD/severe effective disorder as this is one of the symptoms of those disorders.",
"It's wrong that we want to forget it. The reason it sticks in our head is because the jingle has made a deep and lasting impression on us, which it was meant to do because the jingle-writer got the inspiration for it from Satan, with whom he made an eternal pact.",
"It’s a combination of the way your brain works/psychoacoustics. Human ears are extremely well developed and quite good at hearing very specific frequencies and formants that are located within the normal frequencies of human speech. This has a clear evolutionary advantage for obvious reasons. Now add to that the fact that our brain is just a pattern recognition machine, e we have working auditory memory that functions in many ways like a computer. Have you ever been speaking with someone and when they first speak, you don’t hear/understand what they said, but before they can repeat themselves, it suddenly registers? What actually happens is your brain basically rewinds that piece of frequency content information and plays it back for you without you even realizing it happens. Some people are better at this than others, I.e. musicians. I would honestly compare it to kind of a day dream. Kinda like how dreams don’t make sense, and sometimes involve memories mixed up with random occurrences. Something most likely triggered the memory of that song, or it was buried somewhere in that giant filing cabinet that is in your head. Memory, like dreaming, is still not completely understood. Edit: And the reason that many songs/certain melodies are so catchy is just because the frequency information (notes) are related to each other in ratios that are psychologically satisfying."
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nxhjci | What is a colloid? | Chemistry | explainlikeimfive | {
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"A colloid is when you've got one material dispersed evenly in another but they're still separate particles. Milk is a colloid of (mostly) fat dispersed in water. Emulsions, like mayonnaise, are also colloids. The colloid is stable (don't settle) and mixed well enough that normal filters won't separate them (if you pour milk through a coffee filter you still have milk). This is different than a suspension, in a suspension you can filter out one substance from the other."
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nxilgt | Why can screens only be viewed from certain angles when wearing sunglasses? | I have noticed for a while that when wearing my sunglasses in the grocery store the screens of the self checkout appear to be off/black when I approach them from the side and I can only see what's on the screen when I'm in front of it. Today I was on the bus playing a game on my phone and the game plays horizontally. I stared at it forever thinking the phone screen was turned off until I realized I could only see the screen when it was vertical. So, why does the light only pass through my sunglasses from the "correct" angle? | Technology | explainlikeimfive | {
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"your sunglasses are probably polarized because it helps against glare from the sun. LCD screens also contain a polarizing filter to make sure only the color of light you're supposed to see comes out (if you take it apart the whole screen turns white) the two interfere with each other",
"Line waves can have different orientations. This is known as polarity. Sunglasses reduce the amount of light hitting your high by blocking light base on polarity. Imagine, for example, that light could be \"up-and-down\" oriented or \"left-and-right\" oriented, at random. Your sunglasses have filters which only let \"up-and-down\" light through and block \"left-and-right\" oriented light, thus blocking 50% of the light hitting your eye. Computer screens can emit light only of a single orientation. So when you, for example, turn your phone, you are turning the orientation of the light it is emitting to light that your sunglasses block."
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nxiqxf | How can a mainland Chinese company ship a product overnight to the US (Often with free shipping) while a similar parcel & product class from Canada usually takes nearly 2 weeks to make a shorter trip? | Economics | explainlikeimfive | {
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"The product already is in the US. They ship it there in containers and distribute it from warehouses. Shipping from China takes a few weeks. Air freight is quick but very expensive.",
"Chinese subsidies are a thing but more likely the company has a local distributor. They don't wait for a buyer before shipping. They ship over a whole container load by boat, which takes weeks, but is the cheap per item. They hold them here in a warehouse until customers are lined up, then ship from the stateside warehouse.",
"China's government heavily subsidizes shipping of goods to make their products more attractive, more affordable, more attainable for Americans. They know Americans won't want to wait 3 weeks for an iPhone case or pay twice as much to ship it as the item costs. By subsidizing the shipping, it allows companies to sell directly to customers, growing their business, increasing economic output, employing more workers, etc.",
"The Chinese company probably has the volume of China- > US business to make customs pre-clearance and duties/tariffs a done deal. The Canada- > US company probably doesn't, or hasn't bothered yet. So that Canada package if you look at the tracking history probably sat in a customs warehouse for better part of a week. The China package was precleared through customs probably before it left for the airport."
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nxjgyq | How do bees get back to the hive when it starts pouring rain if they can’t fly in the rain, especially when it keeps raining for days and days? | Biology | explainlikeimfive | {
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"The truth is that not all bees get back to the hive and when conditions are extremely unfavorable they may even die while not able to return. However, bees are exceedingly good at reading and even predicting the weather. They are so sensitive to weather conditions (air pressure, humidity, etc) that humans can predict very short term weather by observing their behavior. For example, you're out tending your apiary when a sudden squall hits and you're wondering if you should pack it up for the day and head home. All you have to do is look at the hive entrance and watch the activity. If the bees are going out as much as they are coming in then the weather wont last that long. If you see no activity or only traffic heading into the hive that storm will most likely last a while. As for bees that get caught in the rain, they'll find shelter that they can hang out in until the weather subsides and will die if they cannot fly back to the hive in time.",
"It’s currently raining lightly…. My bees are doing orientation flights and a short hop over the fence to a flowering hedge behind the house. Don’t think they are doing long range to the acres of blackberries about 1/2 mile away",
"I’m sorry, I live in Southern California…what is rain?",
"African bees can handle the rain actually, as well as their hybrids (which is why the hybrids were made in the first place. They're hard working bees!) Bees predict the weather better than meteorologists!"
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nxk2kp | can someone explain the psychology behind the reluctantly to admit when you're wrong? | Biology | explainlikeimfive | {
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"An aspect that the answers so far offered haven't touched on is \"[Cognitive Dissonance]( URL_3 )\". When something challenges what you assumed to be true, it's a deeply uncomfortable sensation. This discomfort is a motivation behind some rather odd behaviours, but the main thing is that it makes people reluctant to change their minds - instead ignoring or undermining whatever has challenged their beliefs. It's easier to think of some way to make the new information seem irrelevant (e.g. [special pleading]( URL_1 )) / unreliable / untrue than to re-evaluate everything in your life that's based on whatever it challenges - especially if the discomfort of cognitive dissonance is helping you to not think too deeply about how well you're doing at inventing ways to discard the challenge. There are a *lot* of [Cognitive Biases and Logical Fallacies]( URL_0 ) are available to recruit into this process, but the motivation is generally the Cognitive Dissonance. There are additional motivations, such as saving face (worrying that people will judge you negatively for changing your mind) or the [Sunk-Cost fallacy]( URL_2 ) (worrying about the wasted costs incurred by the belief) that might be significant depending on the individual & circumstances.",
"I'm sure it's something more complex than what I'm gonna say but We are taught for the first several years of our lives that being wrong is equal to failure, and that failure isnt just bad, but that it also decides your future. So at a certain point it probably just gets easier to dig in and say your right then deal with the shame we're told to feel about being wrong. Cause you know shame is painful and shit",
"There’s are some very interesting physiological and psychological studies from the last 10 years that get into a potential chemical element. But for ELI5: stubborn people feel rewarded for sticking to what they believe more so than they do for learning and adapting to new information. Some of this relates to the reward of belonging to a group over the desire to objectively evaluate the accuracy (or moral values) of that group. This is also why such people will self-victimize, a way to validate their group and belonging by preemptively attacking an often imagined foe, which also often has traits the group itself has but is very insecure about."
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nxld2x | Why do text articles that are written on popular news, hobby, and aggregate sites have typos, errors, etc.? I thought they wouldn't want to pay any real "editors," but why not just use Grammarly or spellcheck what they write in a word article? | Other | explainlikeimfive | {
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"A lot of the writers are underpaid and overworked, writing things they don't care about or might even hate. It gets overlooked because it's still bringing in revenue, and they're still putting out as much content as they can for cheap. They basically don't care.",
"Poorly edumacated. I remember my college English professor spending a whole half hour making sure we knew the difference between it's (contraction) and its (possessive)."
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nxlhrc | What actually causes that tingly feeling when your hand falls asleep? | Biology | explainlikeimfive | {
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"When there's pressure on your limbs for a while, their nerves can get a bit compressed and that fiddles with their ability to communicate with the brain, creating a tingling sensation",
"Its actually a brachial plexus palsy aka the nerves in your arm pit that get compressed. Yes you can compress others but when your whole hand goes to sleep it's all in the pit",
"To add to u/Chocolate_caffeine’s answer, not only the nerves in your hands, but the nerves in your arms, specifically the elbow. If you sleep with your arms bent, or you work with your arms bent, that can cause swelling which puts additional pressure on the nerves. If it happens frequently or it wakes you up, you should see doctor. Sleeping with your arms straight can help relieve the problem."
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nxm5ey | What is happening when a person is too scared to scream? | Biology | explainlikeimfive | {
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"People know the old saying \"Fight or Flight\" when in response to danger, but don't know the third, most popular option, Freeze. A lot of animals, and humans too, in response to a threat will stay still and silent instinctually to not draw a potential danger's attention to it, either by hoping to remain unseen or not do anything to make the threat single them out among possible targets. Some predators hunt instincts are triggered when something tries to flee it, Freezing might prevent that. It's purely instinctual and can be hard to overpower, especially if it triggers at the wrong threat (for example, freezing won't save you from an incoming car or Tsunami) When one realizes they are spotted or targetted, or the threat is about to attack regardless of freezing, screaming becomes the next step. Screaming is a social animals response to danger by alerting others in the area of a threat, either as a call for help, or using ones last moments to give their fellows a running start."
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nxm9s2 | During sexual stimulation, how does the body 'decide' when to trigger an orgasm? | Biology | explainlikeimfive | {
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"Ever watch a video of someone putting elastic bands round a watermelon? They keep adding bands and nothing happens, until they add one more, and you have an explosion of watermelon pulp, and a lot of cleaning up to do ... When your genitals are stimulated, some neurons in the brain and spinal cord linked to those nerves shift to an excited state. If the nerves continue to be stimulated, the neurons move into a more excited state, and also start exciting their neighbors. Eventually, the region of excited neurons reaches some different neurons that link to nerves that trigger an orgasm - a set of cascading reflexes through the muscles in the groin that trigger physical aspects of orgasm. At about the same time, all the excited neurons dump a load of neurotransmitters as they drop back into a low-excitation state - this is why orgasm makes you feel good. The neurotransmitters include oxytocin, which helps social bonding and feeling close to people. The process then starts again - for young people, excitation may begin again in a few minutes, and they can have another orgasm soon after. For older people, the refractory period before excitation can build up may be much longer - days or weeks. The excitation phase can obviously also be influenced by other factors - visual, aural, olfactory and non-genital tactile stimulus can feed the excitation phase. Anxiety, stress and depression can dampen or suppress it. And there are more direct nerve links and reflexes in the spinal cord - these can shortcut or bypass some aspects of the excitation/release cycle. In particular, vibratory stimulus can be used to trigger orgasm and ejaculation in men who have suffered spinal injury, and who have no direct genital sensitivity. As an older man who has had issues with long refractory periods and anorgasmia, the discovery that a strong vibrator can be as effective for a man as for a woman has been a wonderful revelation.",
"It is basically over stimulation, your body can't take it anymore so it releases all the good chemicals to calm you down and make you feel all better..."
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nxmhxv | Why do we get goosebumps when listening to music that moves us. | Biology | explainlikeimfive | {
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"Goosebumps are an evolutionary vestige from a time when we had fur. When hairy mammals experience events or stimuli such as mating, competition or defense (adrenaline spikes), the skin pores that hold hairs stand more upright making animals appear larger. Cold weather also triggers this response, the hairs stand more upright capturing more air in between each hair creating a natural insulation like a parka jacket.",
"Music keeps the happy center in your brain guessing. Is the good part of the song going to be now, maybe latter, maybe after this riff, and then BAM - all those happy (dopamine) triggers get pulled and you get goose bumps. Note: as with all thing has to do with the brain, scientists are still not 100% sure. Why is brain high jacking the function for cold weather reaction and linking it with the pleasure center? We don’t know.",
"Not everyone. Only certain people... Someone posted about this a few months back. It's about how your brain is wired."
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nxnh5u | How is the newer cars are more fragile during an accident but are more safe for the passengers | Physics | explainlikeimfive | {
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"The newer cars are more fragile. This means that they're more likely to deform and break -- but, here's the key. Deforming and breaking saps some of the force of the collision. If the car were built strong and rigid, more of the force would be transmitted through the frame and into the body of the car. Designing the car to twist and warp and deform means less force gets put on you, the operator.",
"Going fast doesn’t kill you in an accident. It’s the sudden stop. It’s why you can fall onto an airbag from 50 feet and be fine, but fall onto concrete and you won’t be. Older cars yes usually were more solid, not crunching or crumpling in the accident. But in an accident when those cars would suddenly stop, your soft fleshy body would still go shooting forward/backwards/sideways depending on the accident, and smash up against that hard, solid car. We’ve invented airbags that deploy to help prevent this from happening, but we’ve also done what you said, made our cars crumple. That’s because when our cars crumple, instead of stopping suddenly, the crumpling of the car means you slow down over a longer time, even if that time is only half a second, it can drastically reduce the force on your body during an accident. The crumpling of the car absorbs energy from the accident, meaning there is less energy to do damage to your body. Cars could be made as a solid block of steel impossible to break, but cars aren’t designed to protect the car, they’re designed to protect your soft squishy body inside.",
"If you are talking about how cars \"crumple\" more, the number one cause of death in an accident isn't being crushed, it's the sudden jolt and hitting the car itself. Sturdy cars might survive a collision with little damage to themselves but in doing so, they transfer all that momentum into the passengers. By allowing the car to crumple more easily, it makes the actual stop less sudden and thus less lethal. All that kinetic energy goes into the car rather than you. Think falling onto concrete over falling into water. Yes, at a point, they are both fatal, but that point comes sooner to concrete than water. That's because concrete has no \"give\" and stops you all at once while water stops you slowly over time, thus you don't feel those intense, fatal g-forces. Note that these cars are also built with cages around the passenger and drivers seat to prevent a car from crumpling you death, so there is a sturdy part of the car protecting you.",
"They design them to be. Cars nowadays are designed to destroy themselves to take the brunt of the damage. The thinking (and rightly so) is a human is worth a lot more than a car. Seems kindof simple, but in the 50s and 60s, even though every car designer would have agreed with that sentiment, the knowledge on how to do that simply (so it could be made well but cheaply) and safely just didn't exist. I mean the solution back then for an uber survivable car before lapbelts then Volvo's 3 pt seatbelt, then airbags in the 80s would have been to fill the inside of the car with foam or wrap the passengers with bubblewrap. And not that the concept of crumple zones didn't exist.. its just it took a lot of experimentation (build and test) on how to fold, bend and cut metal so that when it received a great impact force, it would warp and deform in a way to send the force away from the passengers. With the advent of computer modelling this got a LOT easier to model, thus a lot cheaper. Also more energy absorbing materials (i.e. plastics, foams etc.) became feasible. The old cars from the 50s and 60s are like giant rigid metal tanks; the most deformable part is the big void in the middle where the squishy humans live. Modern cars, the strongest part of the car is the safety cage with the squish humans - the rest of the car throws itself literally under the bus to sacrifice the humans. Yay car.",
"The energy from a car crash has to go somewhere, and it is safer for it to break the car than break your bones."
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nxnywq | why does predicting things in space (outside the planet) seem to be a lot easier than predicting weather on Earth? | Physics | explainlikeimfive | {
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"There aren’t that many variables in deep space. There’s only a few nearby objects massive enough to exert meaningful gravitational influence and so things move very much like clockwork. Eclipses and transits can be predicted with extreme accuracy many years in advance. Weather is a much more complicated system driven by fluid dynamics and thermodynamics in gases and liquids on a planetary scale. It’s not a dozen cosmic billiard balls moving in circles, it’s a nearly infinite number of molecules sloshing around unpredictably.",
"Earth's enviro-sphere is pretty complex. Interactions between ground temperature, planetary albedo, minutes of sunlight, time of year, snow, water, foliage cover, water temperature, ocean currents, the magnetosphere, ionosphere, im-probably-forgetting-a-sphere, wind speed, air pressure, air _quality_, all are one big non-linear complicated mess that we _think_ we know how to simulate (obviously, our forecasts are pretty good), but probably have only just scratched the surface on. I mean, there's a reason why more accurate climate and weather change prediction models need to run on supercomputers. Stuff in space on the other hand, by and large, follows Newtonian physics. At least as far as most practical purposes. An object at motion stays in motion etc. Once something is orbiting something larger, it either continues to orbit, the orbit decays or is perturbed, or something accelerates or perturbs it out of that orbit. For most purposes, every body in our solar system can be thought to be as part of one or two two-body systems. Earth orbits the Sun. The moon orbits Earth. Apollo capsule orbits the Moon. Is it true that the sun affects the orbit of a capsule in orbit around the Moon? Absolutely it does. So does the Earth. BUT, since gravity is inversely proportional to the distance, the effect of the closer body has a much more significant effect; often to the point that the other bodies' effects are negligible. Having said that, we do have a good idea of how say Jupiter's gravity affects Earth's orbit around the sun (exactly how and how much of an effect it is I don't know, but its there), but its impact is somewhat negligible compared to the math of us flying to the Moon or Mars or whatever.",
"What do you mean by \"predicting things in space\"? Weather is mathematically chaotic, which means it outcomes change dramatically with only tiny differences in input. Ergo the ability to predict accurately degrades significantly with increased time. By comparison motion of objects in our solar system are (for the most part) two-body systems, which are mathematically stable. There really isn't any link between these two things, and I have no idea why you've decided to group them together in this question. You've basically asked why is \"hard-thing\" hard to do when this completely unrelated \"easy-thing\" is easy."
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nxo3c4 | So everyone is talking about this year's US inflation, can anyone explain why it's so important? | Economics | explainlikeimfive | {
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"Inflation, broadly, is what happens when money becomes less valuable as a result of more money being injected into a given economic system. In this case, spending went down during the pandemic, and a lot of stimulus money wasn't actually used. Now that the country is reopening, a lot of people are starting to spend that saved-up cash. The current inflation is both a good and a bad sign; it's bad because it obviously means prices will go up on essentially everything, but it's a good sign because it indicates that a lot of people are starting to spend money again at pre-pandemic rates, indicating that the US is returning to economic normality. At the same time (on a personal level); inflation is actually a *good* thing for debtors, as debts don't inflate with the currency, thus the functional value of the money you owe goes down with inflation.",
"We've escaped inflation in the past by increasing production faster than the money supply. During covid the opposite happened. Production slowed when people were kept home from work, while the government injected massive money (covid relief) into the economy. The government replaced the lost wages, but not the trillions in goods, and services that would have been produced. Supply vs demand is what drives prices up.",
"In the US wages have remained stagnant since 2009, the value of money going down paired with the rising cost of living hits a majority of americans especially hard. When the average citizen suffers they--the engine of industry suffers and the economy as a whole goes down as a reflection of this. Similar impacts can be felt in other countries but i dont have those numbers."
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nxonio | How exactly are emails sent, like the actual process of the data getting sent to another device that’s for example on another continent? | Technology | explainlikeimfive | {
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"There are a bunch of standard communications protocols that make up what we call \"The internet,\" like **H**yper**t**ext **T**ransfer **P**rotocol (http) which transfers webpages from their server to your device. When you send an email, your computer converts the text and the relevant formatting information into a message, which it transmits to the recipient's mail server using a protocol called Simple Mail Transfer Protocol (SMTP.) When a user \"checks their email,\" they download messages from the mail server using one of two protocols - Internet Message Access Protocol (IMAP) or Post Office Protocol Version 3 (POP3.) Essentially the process is - you compose an email, SMTP sends it to the recipient's mail server. Recipient downloads the email from the server using IMAP or POP3.",
"Hi :-) How Eli5 would you like it? ;-) - E-Mails aren't getting sent from your outbox to someone's inbox, - but rather over your internet provider's connection - to your email service, - over their internet through different connections across the globe, - to the recipient's server... - Where it waits to be downloaded (Either until they check or sending out a \"Hey, you have new mail\" to their client). & nbsp; Let's say your mailbox is mysupergreatmailbox444 at URL_0 . and you send a message to Germany, e.g. ilovetogetmailsfromoverseas222 at URL_1 . - You write the E-Mail and hit send. - If you use an email client, there will be settings like server, port, account password, and so on. - Internet & Computers doesn't work with names like \"Hotmail\" or \"GMX\", but with IP addresses (numbers like 123.222.127.333 or a more modern format). - Your computer asks your internet provider or other \"DNS\" (Domain name service, basically a phone book) what IP address (a number) URL_0 has. - Then your e-Mail client will connect to that server's number with your log-in data, trying to establish a connection. (If you write an email on your email provider's site, that step basically gets skipped. You instead log in to the website and save the email there directly.) - Hotmail then saves your mail to your account's outbox, sends it to the receiver. If it fails it will retry a couple of times. - Similar process. Hotmail asks a DNS what IP-Address URL_1 has. Then tries to send the data over the internet tubes to that server's IP. - Each transfer is made up from different little pieces of information, and gets collected at the other end. So your eMail might get send in little chunks across different routes, servers, across sub sea cables, ground lines, satellite. Imagine you write a 10 page letter and send each page through a random postal service. The recipient sorts them if they arrive out of order. If a page goes missing, the recipient will ask for it again. It's rather chaotic :-) - The recipient's mail client will check their provider's (GMX in the example) server--- - You've guessed it. The E-Mail client will look up GMX's IP address, connect with log-in data. Send and download messages. - The recipient's E-Mail program uses either a protocol like IMAP (TL;DR: Synchronizes new messages with the server and your other devices) or the older POP3 protocol (Basically downloads and deletes). - The E-Mail client will download & display the message. If they use their E-Mail provider's website, they will display the mails as website to look at and thus provide a human interface to the saved E-Mails. Never have the recipient's E-Mail program and yours interacted directly. Not unlike regular mail."
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nxp8m0 | How did homographs come to be? Was it people misusing words? | Other | explainlikeimfive | {
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"In English this normally happens due to one of two causes: 1. Two words with different origins that ended up being spelled the same but kept aspects of their root for pronunciation. 2. Words with the same root where accent symbols never made it into English - eg live and live (“I used to *live* in New York” and “now we go *live* to New York for the Yankees game”). Other languages annotate their letters for this stuff ì, í, î etc to let you know the vowel changes or where emphasis is placed. English doesn’t - partly because vowels don’t consistently map to letters (this is often due to point #1 above) so an “e” could be one of about a dozen vowel sounds and you’re just supposed to know which one to use. This is in contrast to languages like Spanish where there are five vowel sounds, that each always map to the same letter, and the é á í etc tell you when the emphasis syllable changes.",
"all language are fluid and changing, and spelling and speech are not always insync. like \"live or live\""
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nxpbbz | Does white/grey brain matter changes in aging make you bad at learning? | Biology | explainlikeimfive | {
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"The white and grey matter does change as you age and has impact in your memory retention. But the learning part is effected by a different mechanism. When you are a kid your brain is very flexible in the way it wires and rewires, making you very adapt at learning new things. As you age, the neutral connections in the brain become more and more strengthen, allowing you to do a number of tasks without much of a mental effort, something we usually call muscle memory. A downside to that is that your ability to learn new things go down."
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nxph5x | What causes the squeaky sound we sometimes hear when we rub our eyes? | Biology | explainlikeimfive | {
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"The squeaking noise is escaping air that was trapped in the lacrimal system—the structure housing the tear ducts. When you rub your eyes, you manipulate and put pressure on the tear duct, which causes a “squishing sound of air and tears.” (Sorry stole from Google)"
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nxqgj2 | - How does a sailboat travel faster than the wind? | In a recent Veritasium video, they discuss that a sailboat can travel further downwind than the wind speed. Steve Mould, in a reaction video, explained how a boat can travel faster than the wind at an angle, but not really how it can end up further down wind than the actual wind speed. I’m having trouble connecting these explanations…Links below for both videos. URL_0 URL_1 | Physics | explainlikeimfive | {
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"So, in the Steve Mould video, you should have learned from the stick wheel demonstration that the distance your boat moves can be greater than the distance the wind has moved in the same period of time, provided you're at an angle to the wind, right? Well, as you might imagine, that's great if you want to go in a different direction to the wind, but not so much if you want to go in the same direction. What you do then is once you've gone a fair distance one direction, you turn your boat and your sail so that you're at the same angle to the wind but in the opposite direction. This way, you've made two long stretches of movement in directions different to the wind, but the total distance you've moved just in the same direction as the wind is still higher than the distance the wind has moved in the same period of time. At 8:49, Steve talks briefly about tacking, the method of moving against the wind by making short movements at alternating angles to it, and the same principle can work downwind.",
"You sail when wind is pushing you. Wind pushes you unless you’re travelling the same speed (assume there’s no propellor or anything just a sail). More particularly it’s the speed in the wind direction. So if the wind is blowing north at 3mph you can be going no more than 3mph north. However there is nothing stopping you going 3mph and 4mph east at the same time. This means you’re actual speed is 5mph (pythagoras). You receive the force pushing you east through the use of the sail as a wing. Even though the wind is blowing north, the sail’s shape makes it feel a force east (lift) in addition to the force north (drag)."
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nxqjao | What keeps the microbiota in our gut from growing infinitely and taking over our body? | Biology | explainlikeimfive | {
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"Our immune system. Once we're dead and there's no more immune system, they do grow and eat our bodies.",
"I mean, they \"grow infinitely\", keep feeding on the nutrients coming down through the intestines, and they multiply. And periodically your large intestine extracts the water and \"compacts\" everything, and then you poop the microbiota out. That's what poop is. They are too big to pass through the intestinal wall into your blood, and any that do are killed by the immune cells in your blood."
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nxrz1x | VHS won the battle vs Beta. Why? | Technology | explainlikeimfive | {
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"I would be curious if anyone has any source data for what I was always told; someone on the VHS side of things convinced several of the main producers of porn to adopt the VHS format, and from that time betamax was losing the battle one inch at a time."
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nxsr28 | Difference between strength/hypertrophy/endurance | I understand that you train low rep, high weight for strength, low weight high rep for endurance, and hypertrophy is somewhere in the middle. But what actually happens in the body to cause these differences in muscle growths due to different rep ranges? | Biology | explainlikeimfive | {
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"strength requires (in addition to neurological adaptation) and increase in contractile fibers, aka muscle fibers. this increase in muscle fibers is one aspect of hypertophy. these changes are not that big in appearance, so you can get a lot stronger at single repetitions without necessarily getting big. endurance is aided by sarcoplasm, which is a fluid containing water and sugars that your muscles can use for energy. this is stored near the muscle fibers for them to use, and though it does not contribute to contractile force, it helps the contractile fibers work over time (eg for high rep sets). this fluid occupies a lot of volume, and will contribute significantly to a “swollen” appearance, or the visual aspect of hypertrophy."
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nxt9j5 | How come animals can eat raw food and be fine but humans get sick from it? | Technology | explainlikeimfive | {
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"Humans don't get sick from eating raw meat. They get sick from eating raw, *contaminated* meat. We can eat as much raw beef as we want as long as it's healthy and fresh. Most of us just don't like it. Animals don't store food, they eat the kill immediately so it doesn't have time to go bad.",
"It's worth noting that our species may have come about specifically because our predecessors learned to cook food. We simply haven't needed the iron stomachs of some of our relatives.",
"Raw meat, in particular tends to make us sick because we have stored it for a while after it's died, allowing things to grow on it. Predators eat their kill right away. Raw meat is often OK for us if the *outside* where bacteria grows has been seared (see Pittsburg rare steaks or ahi tuna) or if the meat was prepared the same day it died or flash frozen near time of death and thawed near time of consumption (Sushi is one or the other depending on proximity to the ocean.) Scavanger animals like vultures, on the other hand, have developed special resistances to the kinds of bacteria that grow on days old carrion."
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nxtck6 | How can instruments be in a key? | Background on me: I am a classically trained trombonist who struggles with music theory. I know that a trombone is in the key of Bb, but what does that mean? The key is determined by the piece your playing? Additionally, a trombone with an F trigger is shifted into the key of F when the trigger is depressed (same with the G trigger on bass trombone). What does that mean? For me it just means that first position is now 6th. | Other | explainlikeimfive | {
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"With instruments it means that the notation is conventionally transposed. For example: a piano is easy to play in C and music is easy to read in C. However, a Bb trumpet is easiest to play in Bb. So music for it is commonly written in Bb. But Bb is more difficult to read, unless you enjoy lots of accidentals in the key signature. So the music as written as though it is in C, but C on the stave is sounded as a Bb, D is sounded as a C, and so on. It therefore means that music in the easiest to read key is easiest to play.",
"Some people are kind of missing the boat here. The key the music is written in is related to, but not exactly the same as the “key” of the instrument. A B-flat trumpet, trombone, tuba, baritone/euphonium are said to be “in B-flat” because that’s the fundamental pitch of the instrument with no valves pressed/slide in first position. You’re a trombonist, so you know what I mean when I say “pedal B-flat,” right? That is the fundamental pitch produced by the length of tubing that makes up a trombone. A euphonium is the same length. A B-flat trumpet is half the length. A B-flat tuba is twice the length. There are also C trumpets and C tubas often played by professional musicians...they can still play the same music written for B-flat tuba or trumpet on their C instrument...they just have to adjust their fingerings accordingly. Now, for woodwinds...what makes it an “E-flat alto saxophone?” I’m not as sure of this. If you cover all of the holes, you get a concert-pitch D-flat. If you don’t put down any fingers, you get ...E natural? I think that’s right. Anyway, my best guess is that the E-flat scale is the most natural one to play by just putting fingers down and not using the “accidental” keys (like the pinky G-sharp key, the C-sharp key, etc). I am not totally sure of that. Just an educated guess. In any case...what “key” the instrument is in, is a property of the *instrument*. The music is written transposed to that key for the sake of convenience and making it easier to move between instruments while keeping similar fingerings.",
"When a Bb instrument plays a C major scale (so no sharps or flats), it will be the same notes as a piano playing a Bb scale.",
"Ok so for brass instruments, they used to not have valves. They basically had tuning slides which would changed the fundamental note of the instrument (for you this would be your pedal Bb). The music would be written the same, but the notes would be different. They would only play notes in the harmonic series (all the notes in first position on your trombone). This somewhat outdated convention remains. Horn in F was common, so french horn is written in F. Their F sounds like a concert C. This is different from your trombone being in Bb, your F sounds like an F, the Bb just describes the fundamental note on the instrument."
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nxtcxw | how come when you swallow something in a weird way, it feels like that object is still in your throat? | This happens to me most often when I take my morning meds. I guess I’ll swallow in a weird way and then it feels like I have a pill stuck in my throat. I just finished dinner and now it feels like there is a piece of pork in the back of my throat! Y’all ever experience that? Why does that happen? | Other | explainlikeimfive | {
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"There are a couple of things that could cause it: (1) It *is* still stuck in your throat. This usually doesn’t last too long, but a pill could get stuck in your throat without blocking your airway or your esophagus (so you’d still be able to breathe and drink). (2) It went down rough and irritated your esophagus. This is especially likely to cause the feeling if your esophagus becomes slightly inflamed, because then it is literally a little narrower."
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nxthn1 | can someone explain the great filter theory | Earth Science | explainlikeimfive | {
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"The universe is really old and really big. So there should be lots of aliens around doing things we can see. But we don't see anything. So where is everyone? What if, *something* kills them off before they do something we can see? That *something* is what we call the Great Filter.",
"There's also the chance that we've passed the great filter. Perhaps intelligence to our degree is rare. Maybe mitochondria are a biological fluke. Maybe life just is really rare in general.",
"The Great Filter is the idea that the evolution of life and technical development has great hurdles to overcome on the way to being a species capable of being detected on a galactic scale. Each of these steps is a filter that prevents some part or all from moving onto the next step. The fact that we don't look out and see intelligent life in the universe suggests that there is/are filter(s) that are just so great that it's either impossible to overcome them or they're very difficult to overcome. So the possibilities of these great filters could be: So the development of life in the first place. The development of multicelluar life. The development of intelligence. The development of civilisation. The development of technologies that could wipe you out such as nuclear weapons. Then there's also ones like nearby supernovae, gamma ray bursts, asteroid strikes, massive solar flares, etc. Then there's also the possibility of being discovered and wiped out by another alien species. Are these all great filters? Are we past them? Are they ahead of us? Are they all filters? If we were to discover alien life in our solar system that was primitive it would suggest that there's a higher possibility that the great filter isn't just the creation of life and so is either one of the steps after that or quite possibly ahead of us. The more primitive life we find the greater the possibility that we're going to get wiped out."
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nxtneo | Why do people get tired, but when you go to the place you want to sleep, you can’t sleep? | Biology | explainlikeimfive | {
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"Sometimes your body is tired, but your brain isn't. So your body says \"sleepy time,\" but when you get there, your brain says \"thinky time.\"",
"This is often an issue of sleep hygiene in our modern society. If you spend time on electronics in your bed, your brain associates the spot less with sleep."
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nxu09p | what are “natural flavors” on ingredients labels and how do we extract them? | Chemistry | explainlikeimfive | {
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"It's just an umbrella term to protect their recipe. It could be anything from mint flavor to vanilla to natural alternatives to familiar flavors like fake vanilla made from wood extract. They're extracted by taking natural substances and using solvents, often times alcohol, to extract and hold on to the flavor. Vanilla extract, for example, you can make at home by soaking vanilla beans in vodka or everclear for a few weeks/months.",
"The FDA rule is: *\"The term natural flavor or natural flavoring means the essential oil, oleoresin, essence or extractive, protein hydrolysate, distillate, or any product of roasting, heating or enzymolysis, which contains the flavoring constituents derived from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or similar plant material, meat, seafood, poultry, eggs, dairy products, or fermentation products thereof, whose significant function in food is flavoring rather than nutritional.\"*"
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nxueb9 | What causes the metal taste in your mouth after a head impact/bump? | Recently, I accidentally head butted a large piece of furniture during a move. I’m not sure if the “taste of Metal” is the exact proper description, but if you hit your head hard enough there is a distinct taste that develops in your mouth and teeth immediately after. What is this, and what causes it? | Biology | explainlikeimfive | {
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"Iron, the haemoglobin and myoglobin in your body can be forced out and be tasted, both of these contain substantial amounts of iron."
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nxunh8 | Why do drugs that make you drowsy make you drowsy | Chemistry | explainlikeimfive | {
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"It's different from drug to drug, but many do it because they slow down the nervous system.",
"I'm going to assume you're asking about over the counter sleep aids. Most of these are antihistamines like Benadryl. Histamines have a variety of effects the body, but the relevant part is the regulation of the sleep wake cycle. Benadryl and similar medications block histamines completely which makes your body think they're in \"off\" mode or sleep mode making you tired. This drowsiness is a side effect as these medications are effective at reducing inflammation caused by allergic reactions which is what they're for. There are other prescription sleep aids that work on different systems in the body, but to put it simply, they cause an increase in chemicals in the body that make you tired when there's more of them."
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nxupzv | How did the Spanish Flu end in 1919/1920? | Other | explainlikeimfive | {
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"Viruses mutate and evolve. Over time it evolved to be less deadly. More and more people survived catching it and developed immunity to it. Immunity can be passed onto offspring somewhat and so children born could already have some immunity to it either preventing them from catching it or making it so they could survive it easier. It's actually still around and people still catch it every year.",
"it ran rampant, and infected pretty much everyone it could (500,000,000 people) and killed everyone it could (50,000,000 people). So, it was a world where the most vulnerable had already died, and people that survived had an immunity to it. So the transmission rate dropped below a level that would keep it going, and it started to die out because the rate of spread was lower. It's still around now though.",
"Like this one, the Spanish flu generally killed a specific population; sure there were outliers, just like now, but people who were most likely to die were young adults. They died. Other people caught it and developed immunity. With no one left to kill, and no way to infect it died out. Some viruses kill their hosts before they can infect too many others, thereby effectively putting themselves extinct; that's a big part of what happened with the flu of 1918. Although people did wear masks and socially distance to try to protect their family members. Some viruses are super deadly, but difficult to spread, or rather, require very specific spread. That's why Ebola didn't destroy us all. You really need contact with the blood to catch it, and that is easier to control for. Covid spreads really easily AND asymptomatically, so people who are sick don't know they are getting others sick. And it doesn't kill everyone in its path, like Ebola might if it were more easily spread; its really found a sweet spot of transmissability."
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nxvt99 | How does trace amounts of fetanyl kill drug users but fetanyl is regularly used as a pain medication in hospitals? | ETA (edited to add)- what’s the margin of error between a pain killing dose and a just plain killing dose? | Biology | explainlikeimfive | {
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"I routinely prescribe fentanyl in the emergency department. The answer to your question is very precise dosing. A normal dose of fentanyl is 25-100 micrograms, which is an incredibly tiny amount. At that dose you may feel a bit drowsy but it's very unlikely anything bad will happen. It's easy to reliably give the right dose when you have drugs that are manufactured to strict standards and tested at multiple steps during production. When you're mixing up drugs for street distribution, quality control gets pretty loose. A variation of a few milligrams (a few thousand micrograms) one way or another is no big deal for many drugs, but would be lethal with fentanyl. Another important factor is that patients receiving IV opioids are generally in a monitored setting so we know if their breathing slows down too much and can give them oxygen or even narcan. If you're using recreational drugs alone or with a group of similarly intoxicated people, nobody will know you overdosed until too late.",
"So speaking from some experience, an old friend used to stomp his heroin with fentanyl purchased as a \"research drug\" from China and shipped to a drop house. He was 100% an addict and the reason he was cutting was he was taking his \"pure\" heroin he received, holding a large percentage back for his own use, and selling the stomped on product as \"pure.\" Problem was his supplier had the same ideas and used **carfentanil** to cut it before passing it down to be sold. My friend does his usual and shoots up a hero dose and the rest is in the obituary. [Picture]( URL_0 ) reference for how small of an amount of these synthetic opioids is considered a lethal dose. **Edit:** Because jesus, didn't expect this to blow up. To clarify, friend in question was my half brother, who unfortunately got me on drugs in the first place. I've personally been clean since 92. He started off slinging pot for the mexican mafia back in the late 70's and branched off to coke and speed in the 80's. The wake up call (for me) was when he got shot in the head during a bad deal and managed to live. (The bullet skidded off his skull and bounced around in his sinus cavity before exiting by his eye.) I'd like to say he turned his life around at that point, but he didn't. We fell out after he started using what he was supposed to sell. (Found this out when people showed up at my moms house and held a gun to her during a family dinner.) He pops up every 5-6 years \"clean\" and we catch-up just for him to disappear again. Last time he popped up around 2013 was when he tried to recruit me into his scheme and basically laid it all out. He was dead within the year. Edit#2: As mentioned his H was white, he didn't sling black tar or that brown shit from the middle east, his words; \"My shits pure, I get it from the Asians.\"",
"Hospitals prescribe Fentanyl in *extremely* controlled doses. That kind of precision may not be used when people cut other drugs with fentanyl. A lot of people don’t even know there’s fentanyl in the drug they are taking, so they take too much.",
"The dosage of fentanyl is extremely small. It’s measured in micrograms. To give you perspective, there are 1000 micrograms in a milligram. Think of an regular strength Tylenol. It’s usually 200 milligrams of acetametaphine. The normal dose of fentanyl is like 25-100 micrograms. The margin of error for such a small amount of medication is incredibly small.",
"There was a documentary on Netflix called \"Dope\" it followed different drugs in different cities, users, dealers and cops. There was one on heroin, shows a dealer cutting it with Fen. He says he keeps adding fen till it starts killing users- then the users want it more cause it's so strong it kills people. On the street fentanyl concentrations very wildly, from batch to batch, week to week. What it's cut with, is it veterinary dewormer or shit crystal, some benzos or maybe some baby powder ...anyone's guess. One week you get a weak batch and you have to up your dose. Next week that same dose stops your respiratory drive and you turn purple and die. Although these days everyone and their dog carries Narcan. We have guys just sleeping on a bench get x4 doses up their Nose from concerned bystanders. In the hosp, they know your weight , they have stable concentrations of the drug and the medical staff are pros who know their dosing .",
"A typical dose of fentanyl in the hospital is 0.000025 g. That is an unfathomably small amount. When actual drug companies are making pills or patches, they have the right equipment, quality control, and \\~100% pure fentanyl to start with, to produce doses that are like 0.000025 +- 0.000005 g. When drug dealers are adding fentanyl to spike their product, there is no way in hell they can measure quantities that accurately, mix them thoroughly enough, or even know the purity of the fentanyl they're adding to begin with. Like, I worked in a lab with a digital scale that cost like $8,000 and it *might* have been accurate enough. It weighed to 4 decimal places (+-0.0001 g) so the lightest amount of fent it could weigh would be enough for hundreds of doses, so you'd have to mix them all up together in a big bowl. So you're adding hundreds of desired-doses worth of fentanyl (aka dozens of fatal doses) into a bowl, then stirring or using a kitchen mixer, then scooping it into baggies or pressing into pills and just hoping you've mixed enough that no single baggie / pill has more than 0.00001 g or whatever. It's essentially impossible to mix well enough. Oh and you're guessing at the purity of the fent you're adding to start with. If you assume 100%, then your stuff is weak, because odds are it's not. Guess the starting fent strength too low and now *lots* of your baggies have lethal doses. The difference between a fent dose you can barely feel and a dose that kills you is barely visible. People have died from traces left on a scale used to weigh fent before the thing they weighed. Hospitals and drug companies are equipped to handle chemicals with that level of precision, illegal drug labs (even very very good ones) are not.",
"Drug manufacturer here: drugs that are active in the microgram range have separate and time consuming methods of mixing with excipients. For example fentanyl (which we don’t manufacture) would be geometrically mixed in liquid form. So you dissolve 1gr of fentanyl (that would be like 20 thousand doses) in 1ml of water you thoroughly mix and add any other excipients (emulsifiers, thickening agents, absorbers etc). Then you mix that 2ml solution with 2ml of water. Then that 4ml with 4ml of water. 8-8, 16-16 etc until you reach the the desired concentration. That takes a looooong time of meticulous dosing with expensive equipment. The street version is a dude with a credit card, a plate and some flour.",
"So SOME drug dealers my have no clue but thats not the case for all. there are several major issues with fent in street drugs 1. while x amount spread across the entire amount in a batch of pills/bag/rock ect might be a safe dose. often times the product is not evenly mixed. This is fairly common but it didnt used to be fatal when they were cutting with inert things, you would just have a variety of strengths in across the single bag/rock. Dealers are cutting the actual product with both fillers and fent, with the intent of making more product without sacrificing the strength of the heroine or w/e they are cutting. 1. as a side note to this one. testing. if product is not mixed fully, you could run some of the product through a test kit and it come up pure, but then a chunk on the other side of the bag might have a pocket of unmixed fent. 2. even in a case where things are mixed perfected. lets say they put 1/5 of a lethal dose of fent, in a dose of the product in question. and generally you only expect the person to do 1-2 doses because thats the usual, but what if someone knows that its nonfatal to take 10 doses at once if the product they bought was pure. and decide they want to go hard tonight. whelp you do the math. 3. with mdma back in the 90s it was common for dealers to make custom cuts for batches of pills. they would have mdma, but also other things like meth or heroin mixed in. part of the reason for this was to give their product a special high to try to make it worth coming back to the same dealer instead of getting the product where ever they can find it. it was also because these products have significantly greater withdrawal effects and addictive qualities. 4. People are finding fent on substances they wouldnt expect to be cut with anything let alone a potentially deadly pain killer. 1. this is sometimes caused by residue left on scale between different products. sometimes on purpose :/ 5. Relapsing heroin junkies often od because they do the dose they were doing before they quit, but they were only able to handle that dose because their body had built op a tolerance requiring more to get where they want to get. so we know its already difficult for people doing heroin to correctly measure out the correct dose for them, now add in the wild card of the chance of fent, and beyond that inconsistent strength/presence at all of it thought-out a bag. 6. Double cutting. Where a dealer assumes the product they were given is pure and then cuts it to try to increase their profit margin, not knowing that someone before them in the chain already cut it.",
"Because in the hospital they give you such a tiny amount of it. They know how much to give you. Drug dealers have no clue and people who try it do not realize how strong it is.",
"Fentanyl is so strong, its hard to mix it with a buffer and end up with a homogenous end product at precisely the right percentage. Some of the overdoses were from users who didn't know the drugs they were using had any fentanyl in it. Suppose you are a heroin dealer. Since the beginning of time (for example) milk producers have slipped a little water into their milk to stretch it when they sold it. Heroin dealers do the same with various cheap powders that have no drug effect, the buffer-powder only dilutes the heroin. Well, this makes heroin users angry, and they either pay less or get their heroin from someone else, so what can you do to give your cheap diluted heroin a little more punch? Add a little bit of fentanyl. OK, but...you don't have a modern pharmaceutical lab, just a brick of powdered heroin that you want to mix in some buffer powder to dilute it, and a \"pinch\" of fentanyl. How pure is the fentanyl that you bought from a fentanyl dealer who got it from a Mexican smuggler that got it from any one of several Chinese factories? How pure is the heroin? How accurate is the label on the powdered buffer? So you dump the measured amounts into a large stainless steel bowl, and mix it slowly with a common cake batter mixer. Then you use a measuring spoon to put what you estimate is the right amount in tiny bags to sell to customers. Some of the tiny bags of adulterated heroin have more fentanyl, and some bags have less... Most of the customers are fine after using your product, but...you hear a couple of them died. Heroin addicts die all the time. Did they take too much? Did they have a stroke or heart attack? As a hardened heroin dealer, do you take the time to find out all the details? (or do you stay away, so as to not get a civil wrongful death lawsuit, or arrest for selling?). Some addicts went through rehab, and when they got out, their tolerance was lower, so they died from simply using the amount they used to use.",
"With Fentanyl laced Heroin specifically, here's an example of how it can happen: Take a deck of playing cards. Remove all the aces. - The deck will represent your bag of Heroin. - The Aces are going to represent your Fentanyl. - The other cards are going to represent the Heroin + whatever worthless filler it's cut with. - One Ace is a single dose of Fentanyl. With that in mind, divide the remaining deck up evenly into four piles of 12 cards. Add one Ace to each pile to ensure the deck has an even mix of Fentanyl in it. Now shuffle the deck thoroughly for the next few minutes, and then draw 13 cards. The shuffling is to simulate the cut drugs being moved around/transported/handled, and the mix shifting up, as well as the fact that the powder might not have been mixed perfectly evenly to begin with. The cards you're drawing, are your dose. Take a look at those 13 cards and count the Aces. - If there's one Ace, you get a regular high. - If you find two Aces, flip a coin, heads you survive and get *really* high, tails you're dead. - If you find three or four Aces, you're dead. - If there were no Aces, well, then you barely got high. Draw twice as many cards next time, and repeat, to simulate what a user would do after a weak dose. Obviously this is an over-simplified example, but suffice to say when you're dealing with a substance as potent as Fentanyl, and mixing it in to a powder, it can end up mixed unevenly, and someone can get a hot shot that has too much of it in, and kills them. Not to mention it can happen the other way around. If their first dose ends up too weak because of the uneven mix, that can be equally as disastrous, since they can double up on their dose next time, not knowing their shit is cut with Fent, and end up getting a double dose of the Fent too.",
"The margin of error between an effective dose and a just plain killing dose is called a therapeutic index. Fentanyl has a therapeutic index of 400, meaning it takes 400 small painkilling doses to kill the whole person instead of just the pain. For comparison, morphine has a therapeutic index of 70, so fentanyl is between 5 and 6 times harder to overdose on than morphine, all else being equal. ([source]( URL_0 )) The way fentanyl kills drug users is that they think they're taking morphine or heroin and take way too much because of that mistake. Fentanyl is about a hundred times stronger than morphine ([source]( URL_1 )), so if you try to weigh out four small doses of morphine (which should never kill someone) but you're actually weighing out fentanyl, you've just weighed out enough to kill you. This happens because drug dealers sometimes mix fentanyl into the stuff they're selling as morphine and heroin so they can also mix in cheap fillers and save money without having weak product, but they don't always get the amount of fentanyl right. People who think we should legalize drugs often point to this as a reason. If someone spikes your vodka with xanax so they can dilute it with water and save money, you can report them to the police and the law will make them stop. But drug dealing is still illegal whether you mix in fentanyl and deworming medicine to save money or not, so drug dealers don't have incentives to make their products as safe as possible the way vodka makers do.",
"It's measured very very carefully and precisely. Drug dealers don't know what they're doing and have access to different forms.",
"We just learned recently that having 3x what was thought to be the lethal amount of fetanyl in your system is no longer considered lethal.",
"Being that fetanyl is so powerful and doctors have to be so careful with it, why isn't it used for executions in the prison system? Do away with the cocktail and uae this instead Cheap and easy.",
"Dose is everything. A drug like heroin or cocaine is often taken in milligrams or even grams. It's not a lot, but even a cheap electronic scale can allow you to create doses that are more or less going to be \"safe\" (as in not overdosing on a single dose). Fentanyl is hundreds of times more powerful than heroin and therefore is meant to be taken in MUCH smaller doses. The doses are so small that effectively and safely measuring a dose requires a VERY precise measurement device. In the field of medicine (hospitals and doctors and nurses), they are EXTREMELY careful with their use of Fentanyl, the doses are all measured and monitored with the strictest processes and measurement devices. With street drugs, the quality of measurement and adding of Fentanyl is FAR less consistent and orders of magnitude less safe. This is why someone might take a cap of extacy (Molly) and overdose and die. (Something that has happened to two of my friends, one of which took a cap of E very recreationally, ie first time in a decade that he'd done any drugs, and he died.) This can happen because there are no established safety standards when adding Fentanyl to drugs which has the predictable result of being wildly unpredictable. And also extremely dangerous. Fentanyl is dangerous because it's too powerful to use safely without the strictest standards of measurement.",
"Had fyntenol and propifol (killed Michael Jackson) when I got my tonsils out, at 35. There’s a reason the anestiologist sits there with you.",
"Actual ELI5: This picture should say everything you need to know. [Lethal dose of Fentanyl]( URL_0 ) At the hospital, not only is it only a very small fraction of that amount, but they also very closely monitor how much is ACTUALLY ingested, rather than approximations that are done in street drugs.",
"It’s also mixed with heroin. In the hospital it is pure. Regular heroin cooks down to a golden brown. If there’s even a slightly bluish/greenish tinge there is fentanyl in it and it is greatly potentiated. Addicts see in the news that a whole bunch of people died of overdoses right on the sidewalk where they used and list where it happened and addicts run over there to buy up all that dope before the cops shut it down. Some dealers seek out dope with fentanyl because it’s gets you super high. It’s the amateurs who don’t know what to look for that overdose.",
"The scary thing here is the continual statement that people in healthcare “give fentanyl all the time” Fentanyl should not be given that often.",
"Sometimes drug users don't realize how much is really there (a little but goes a long way) Or they don't realize it is there at all. People can die from fentanyl overdoses because their stuff is laced and they have no clue.",
"To keep it ELI5 - it's simply the dosage. It's kinda like tequila: 1 shot is slightly buzzed, 10 shots is piss-on-yourself drunk, 20 shots is (most likely) dead. Now if morphine is tequila (the more commonly used pain medication), then fentanyl is SuperTequila that's 100x more strong. 1 shot of this stuff is 100 shots of normal tequila. In the ER, they have eyedroppers to measure this stuff so 1 drop = 1 normal shot. Out on the streets, these dinguses are trying to measure super tequila with a shot glass - it doesn't work and people die.",
"Define \"trace amounts\" ? A study of drivers pulled over while under the effects of Fentanyl gave samples showing numbers generally higher than 7 ng/ml (of blood) but less than 20. Some autopsies of overdoses show around 500 to 700 ng/ml, but generally any number over 20 is potentially fatal especially in smaller users The famous case George Floyd supposedly had 11 ng/ml and was showing some very low amounts of norfentanyl, which means his body had just started to break the drug down, something not seen in overdoses as the drug generally kills before its decomposition starts. This is one of many factors that lead all the medical experts brought in for the trial of Chauvin to the conclusion that George Floyd did not die of overdose, that he was murdered.",
"The street fentanyl is made in sketchy circumstances, often imported from countries with... different... quality controls than ours. It is then \"cut\" and mixed in with fillers once it arrives in the area where it's going to be sold, sometimes mixed a few times at a few stages. Someone mixing this stuff up in a shed or secret warehouse isn't going to have any quality control so one pill might have 10 micrograms of the drug, but the next one might have 300. It's often sold to drug users as other opiates, and they don't even know that they're taking fentanyl, thinking it's a different drug like morphine or hydromorphone, and they had no intention of using it in the first place. The hospital fentanyl is made in a proper medical laboratory with strict regulations, and is administered in verified doses, while supervised by medical professionals. When I was in the hospital a few months ago, I was given 4 doses of fentanyl for pain, but was hooked up to a bunch of monitors and had a nurse watching me the whole time.",
"The best analogy for this is chocolate chip cookies. Ever make chocolate chip cookies and some cookies end up stacked with chocolate chips and others have next to zero chocolate chips? Welcome to unregulated drug production. The fentanyl that kills people is that one chocolate chip cookie in a batch that just happens to be loaded with chocolate chips. Then there are other issues like super potent chocolate chips like W-18 or carfentanil. So someone who normally takes the same dose of illicit street fentanyl (ie. eats the same cookie) can have a potentially fatal dose.",
"On the other side of the coin i have some experience. Fentanyl drug users do not administer fentanyl patches as prescribed. They either squeeze the gel out of the patch and freebase it, or they put the patches in their mouth so the drug is absorbed orally. Route of administration changes how much of the drug is absorbed by your body at one time (bioavailability). Transdermal administration (as prescribed) is much slower than oral, inhalation, or injection. Effectively, it comes down to dosing and not being able to gauge it accurately when using the patch in ways other than prescribed.",
"Definitely not ELI5 and doesn’t even really answer the question but there is something you can look up call the “therapeutic index” of a drug. It is the ratio of how much it takes to be toxic vs how much it takes to be effective. It’s one measure of the danger of a drug. From that perspective, fentanyl is actually fairly safe (index of 400) vs morphine which is less safe (index of 70). Insulin (used to treat people with diabetes) is extremely low, like 2-3. That is why treatment of type 1 diabetes is so precarious. Hopefully somebody learned something new today!",
"If I asked you to hold this brick above your head and then let you lift all the weight, you would be find. If I asked you to hold this semi-truck above your head and then let you carry all the weight it would squish you. Why? Because your body has limits that it can handle. The Limits of Fentanyl the body can handle are VERY VERY VERY SMALL. So if the concentration of the drug is high enough, e.g. it is very pure. the amount that you can put on the end of a needle is enough to kill a human. When a drug is prescribed the amounts are known, controlled, tested, retested, surprise tested, etc. When a drug is bought on the street it is manufactured poorly, cut with other material etc. What one \"dose\" is one week isn't the same as the next and any mistake can literally kill you."
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nxwwy1 | In some US States, video recording is legal but audio recording requires 2 party consent. Why are they treated differently? | Technology | explainlikeimfive | {
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nxwzj2 | why can't we think clearly when we don't get enough sleep? | Biology | explainlikeimfive | {
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"Brain is like a thought factory, producing smoke. Sleep is like a wind that carries the smoke away.",
"Sleep is like a reboot... It clears all the junk files, cookies... sorts out things that are important/not-important... Sends important information to long term memory... Prepares useless memories to be over-written... It is basically synonymous to defragmentation of a disk... Makes everything run smoother after we wake up.... When we don't sleep the system keeps hanging and crashing because of all the dump files that has been accumulating."
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nxx3a5 | If my face muscles are constantly working and moving..why aren't they super bulked up like my my biceps and legs? | Biology | explainlikeimfive | {
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"h1ilb8o"
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"text": [
"Because they're not doing hard work. Muscles only grow to be as large as they need to be to do their jobs, because any more would just be a waste of resources. The way the muscles know how large they need to be is through tearing: If the muscles tear because they're doing work greater than what they're able to do without tearing, then that's a sign they need to become larger. Then, once they've become larger, they'll no longer tear doing the same work - they don't need to get any larger, so they don't. Your face muscles are constantly moving, but they're only moving your eyebrows, jaw, lips and a few other things. These are not very hard things to do, and were the muscles to get any larger, they would just atrophy down to the minimum required muscle to do their jobs. If you want to make your face more muscular, you're going to need to figure out a way to suspend a dumbbell from your eyebrows."
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nxy1iu | What exactly is 'Critical Race Theory'? | Other | explainlikeimfive | {
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"Okay my thesis was actually on critical race theory (specifically as one of three theoretical lens used to analyze the issue of mass incarceration) and I'm literally always looking for an excuse to talk about it. I'm gonna try and explain this as accurately as I can with as little jargon as possible, so please bear with me here. Critical race theory is a way of analyzing society, same as other sociological theories. It's a framework that can help people find patterns and make sense of the world and large scale occurrences. This particular theory comes partly from critical legal studies, a popular strain of thought in the early 1980's that essentially challenged the idea that criminal law and politics were separate from one another. This aspect of critical legal studies can still be found in critical race theory. Critical race theory has been developed by many different theorists, which others have noted here results in wildly different interpretations of it, but there are several core tenets that they all agree on: 1. Racism is normalized and a part of everyday life. 2. White supremacy is maintained through ignoring racism and its pervasiveness, and the most overt instances of racial discrimination that cannot be brushed aside are treated with colorblind solutions that do not provide deep systemic change. 3. While many whites suffer due to their class position and other potential circumstances, their race is not a factor in their struggles; in fact, all white people to one degree or another benefit from white supremacy, which results in a vast majority that has no desire to change how society works. 4. Most importantly, critical race theorists acknowledge that race is a social construct. There are no biological or genetic differences separating people into race, not in intelligence, morality, personality, or any other way. Race is a social category, and these categories are used as needed and disposed of when they are no longer useful (we don't see many octoroons these days, do we?). That's the long and short of it. Based on historic evidence, theorists have noticed patterns described above. So to use critical race theory, you look at an issue and go \"assuming these concepts are true, how then can we explain this specific social phenomenon?\" That's literally all it is."
],
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nxyh8z | Why do HDMI cables have such high bandwidth capability when most of the content we watch is usually at a much lower bit rate? | Technology | explainlikeimfive | {
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"h1hjesc",
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"text": [
"Because the data stream you get from YouTube or Netflix is compressed and needs to be processed to create an image. A 1080 TV has 2,073,600 pixels it must draw 60 times a second. Each of those pixels has has 3 color elements that require 10 bits of data to encode for. 2,073,600 pixels * 30 bits (pixel color value) * 60 frames per second = 3,732,480,000 bits/second. Divide that by 1,073,741,824 bits in a gigabit and you get 3.47 gigabits/second required to stream a 1080p video at 60hz",
"Hi :-) The TV doesn't receive high (loss based) compressed video (e.g. not MP4 like you're used to when watching internet videos), and thus video signals need a larger bandwidth. If you attach a blu-ray player, media stick, camera, you don't want to add (more) compression artifacts. Plus there's always overhead, planning ahead for higher resolution standards.",
"To add to what u/schorhr said, the actual data rate for a 60fps 1080p video stream is somewhere around 4 or 5 gigabits per second through an HDMI cable. 60fps 4k is four times that. If you're watching a DVD/Blu-Ray or streaming video, the video source is handling decompression and each frame is sent over the cable as an uncompressed image. If you're playing a video game then the video card in your computer or console is sending each frame uncompressed pretty much as soon as it's done rendering it."
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nxzzjb | Why does fire make things look blurry? | Physics | explainlikeimfive | {
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"h1hotvc"
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"text": [
"The shimmer you see above a fire, or on a hot day in the distance is because air, when heated, expands, causing it to become less dense, or thinner. Light travels faster through warmer, thinner air than through colder, 'thicker' air. Since the air density and temperature isn't uniform, you get a shimmer or haze."
],
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ny0365 | How do stationary space satellite stay in place, and not go around the earth with out falling? | Physics | explainlikeimfive | {
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"text": [
"Geostationary satellites are still orbiting, which means they're moving sideways fast enough that the curve as they fall follows the Earth's surface and so they maintain the same altitude. What keeps them \"stationary\" is that their orbital speed is the same as the rotation speed of the planet beneath (e.g. it takes them 24 hours to make a complete circuit), so they stay in the same place in the sky.",
"They *are* going around the earth, but they're doing it at a speed that matches the earth's rotation. How long it takes for a satellite to complete one orbit depends on how far away it is. At a certain distance, it takes 24 hours to complete one orbit."
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ny0dd4 | Why is nutrition such a difficult topic to research? | There is a massive amount of conflicting research/information on nutrition out there. Eggs are great for us, eggs are clogging our arteries, eating carbs is good and gives us energy, carbs make us lethargic and fat. As someone who, after years of treating their body like crap, wants to make an effort and eat things that are good for me, it seems impossible because at this point I feel like whatever arbitrary statement about food you take (like, eating 1/2 green apple increases your metabolism but only on Tuesdays and Fridays), you will find some type of research "confirming" it. Why is it so hard to have concrete research/evidence of what is good for our bodies and what isn't, at least generally? Isn't it science? How are we supposed to know what to eat?? | Biology | explainlikeimfive | {
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"text": [
"Ethics - Researchers can't lock people up and force them to eat certain foods. So researchers have to rely on willful compliance, which is difficult for most people. Money - Human research is expensive. Conflicts of interest - Food is a big business, and businesses do not like threats to their profits. So they are more than happy to finance research of questionable quality in the name of profits. Time Scale - Some issues relating to diet take years to manifest. And on such a long time scale, there are many other potential contributing factors which must be rule out. Difficulty - Science is hard and new tools & techniques emerge which help researchers do and explore more than they ever could. This drives a lot of the findings that \"turns the field on its head.\" Communicating scientific findings to layman is also very difficult.",
"The effects of nutrition are hard to study for a lot of reasons. One big one is that the effects of a diet aren't always obvious in the short term. You might be eating something now that's bad for you, but if it takes 30 years of eating for problems to manifest you're not gonna know for a while. That's why it took people so long to agree that smoking was bad: One cigarette won't hurt you much, but doing it for years will. You cannot easily study the longer term effects of a particular diet on humans. You cannot control what people eat for years on end, and you cannot trust that they accurately report on what they've eaten for the last several years. Also, human body by itself is: 1. insanely complex and complicated 2. varied from person to person, dependent on climate the person lives in, varied between sexes, between races, genetics and basically due to anything that affects you in any long-term way And than, science is all about control experiments where you change a single variable at a time. That just can't happen with human nutrition. Hard science, e.g. physics, chemistry, etc.. build rigorously on basic, well established, mechanisms of nature. In general, with hard science, when you claim something, you find a correlation, come up with a theory of a mechanism on how you think that correlation comes about and then come up with a way of testing the mechanism by controlling all other factors and seeing if your mechanism really works the way you thought it did. Bio-chemistry would be the 'rigorous' hard science that should be behind nutrition and medicine. Unfortunately there is a huge gap between where bio-chemistry ends and where nutrition start. In some cases, proper bio-chemical mechanisms can be shown. More often though, nutrition come up with claims purely based on correlations from observational studies, where the underlying bio-chemistry is not understood at all. Due to factors like these, the research studies coming out in nutrition have a huge signal-to-noise ratio problem to the point where you can pretty much find them to support any personal pet theory, well accepted by the field or not.",
"For your personal life, it really isn't that complicated. Anything is bad in excess and few things are terrible in moderation. A little bit of awareness of how you eat will go a very long way. To start with, just mind your calories and macros. Calories are simple, this just the energy you derive from your food. If you consistently eat more calories than you expend, you'll grow fatter. If you eat fewer than you expend, you'll lose weight. Tracking calories is an easy way to prevent over-eating. Your basic nutrition macros are protein, fats and carbohydrates (sugars, starches, dietary fibres). All three of them are actually pretty important for your body so, extreme diets aside, you really shouldn't label any of them as simply bad. It's excess that is bad. Where it gets complicated is processed foods. The things that are important to our bodies tend to taste good. And processed foods take advantage of that by including those things in excess in order to make food delicious. Carbs for instance are the most common source of energy for your body. A 100 grams of apple contains about 14 grams of carbs. While 100 grams of whole wheat bread contains 41 grams of carbs. It's a lot easier to overeat on carbs when you eat bread than when you eat an apple. So while one or two slices of bread for breakfast are great. Eating a foot-long sub is overdoing it. Processed food makes it very easy to eat nutrients that are good for you in amounts that are bad for you. On top of that, the way you digest food also makes a difference. When you eat ice cream or a chocolate bar, not only is there a lot of fat and sugar in that food. But the fat and sugar is readily available. Sugar itself is very easy to digest, most of it is absorbed straight into the bloodstream through the stomach lining. That means that when you eat something super sugary like chocolate. You get a huge immediate energy boost as all that sugar is absorbed all at once. Which immediately gets used up by your body and then your energy levels crash again. When you eat something like green beans, it's much harder to digest due to fibre in the foo and the more complex makeup of the green beans. It takes your body more work to digest and as a result, the energy and nutrition contained in the food is released gradually. This provides you with more balanced energy levels and a longer-lasting feeling of being sated. Anyway, wall of text. If you want to eat healthier try this: * Track your caloric intake just to figure out if you're not eating too much or too little, an app like FitnessPal can help a lot. * Track your macros just to figure out if you're not eating too much fat, sugar etc. * If you're willing to give it a try. Start by making your meals out of unprocessed food as much as possible. Fresh vegetables, fruits, nuts etc. When you cook yourself, you have a much better idea of what you're eating. * Exercise. Using your body causes your body to use and process its reserves and food intake much more effectively and it'll make you feel better too. In terms of ingredients, don't worry too much about what's good and bad. Eggs are not a problem in a varied diet but you shouldn't eat anything to excess. The main thing you should watch out for is processed foods because they usually overload on sugars, fats and other things to make the food more appealing to you.",
"You are making a rather simple question more difficult, in a sense. The average human body is relatively tolerant and a modern human diet is generally more than able to provide basic nutrients necessary for good health. Your body will take in what is necessary and dispense with the rest. You cannot eat your way to health. Moderate regular physical exercise, healthy social activity, engagement of mental faculties, a moderate balanced diet is really what will deliver pretty good results. Anything else runs the danger of being \"food faddism\" - unproven or barely correlative results used to promote books, lifestyle and other questionable ideas (perhaps in good faith, perhaps for profit). It is very unethical to test out certain ideas. For example, forcing some group of people to take a diet that might be harmful just to gather enough data for \"research\". Locking a group of people for long periods of time and controlling every part of their lives and environment for the sake of gathering data is unethical. The human body is the result of billions of years of evolution. Many experiments can show correlation but not necessarily causation because of the complexity and time for long term outcomes to manifest. Food is only one part of health. The physical environment, social environment, psychology, physical activity, put different stresses on the body. These are impossible to control (see above). The world with regards to humans lives doesn't operate on certainty, there is chance and risk. If you are asking a question \"what can I eat to guarantee 100% that I will always be healthy and live to 120 years\" or something similar, then you're not recognizing the complexity of the world we live on. Anyone that tries to sell you \"guarantees\" in life is trying to scam you."
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ny0gt3 | What is the reason why humans don’t sneeze while sleeping? | We cough in our sleep and both sneezing and coughing are involuntary, so why wouldn’t we also sneeze? | Biology | explainlikeimfive | {
"a_id": [
"h1hqryz"
],
"text": [
"The body self paralyzes it’s musculature, including the musculature for sneezing and coughing, during REM (dreaming) deep sleep. People actually don’t cough or sneeze during deep sleep. People can, and do, cough and sneeze during lighter stages of sleep."
],
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ny18bj | What happens in sleep that 'cures' puffy eyes and eyebags, and are we able to replicate this while avoiding sleeping? | Biology | explainlikeimfive | {
"a_id": [
"h1if9mh"
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"text": [
"Skin under our eyes are particularly very thin and become lax very easily.. this makes them more transparent to whatever happens under the skin, for example if the blood supply increase it soon starts to look darker than the skin around, also minimal changes in fluid retention under the skin makes the undereyes look saggy. The exact connection between saggy eyes and lack of sleep has not been identified... However, it can be explained that when the eyes overwork and not get the rest that it needs, just as the eyes look reddened because of the increasing blood supply, the skin under the eyes also darken and creates an illusion of making it look kinda saggy... However oversleep can cause saggy eyes because the horizontal position of the body makes the extracellular fluid to accumulate around the face, making the face puffy and under-eyes particularly saggy."
],
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ny37af | If I use my phone before, during and after the toilet. How effective is washing my hands? | Biology | explainlikeimfive | {
"a_id": [
"h1i2mzr"
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"text": [
"Your hands are fine before and during. Just don't touch your phone between wiping and washing, then you're fine."
],
"score": [
6
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ny3b79 | How are Virtual Machines made? | Technology | explainlikeimfive | {
"a_id": [
"h1i4vb3"
],
"text": [
"They reserve part of your hardware and it runs a second OS on that. Running a VM will take away resources from your applications running on the main OS. VMS will allocate the resources, even if they are not needed. Therefor a VM should be configured with minimal resources, especially when running on your personal machine. When running a VM in the cloud there is usually multiple machines that form 1 big machine, which is called the hypervisor. That big machine is then broken down in multiple VMs. These are the ones offered by AWS, GCP or Azure. (Or any other cloud provider) So a cloud VM is run on multiple hard metal machines, when you would shoot one of those hard metal machines with a shotgun, the VM would continue to be online, as the hypervisor continues to live on. When you keep shooting, the hypervisor will eventually die, taking your VM with it."
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ny3ldj | . What happen when two atoms collide? | Physics | explainlikeimfive | {
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"text": [
"Before you read: I am only 18 and my answer is based off my knowledge so far: Depends on the kinds of atoms and how hard they collide. For \"slow moving\" and large relative mass atoms they never actually collide, as they are interacted on eachother by fundamental forces. For charged particles like electrons or protons you have the electrostatic repulsion/attraction. Atoms are neutrally charged, so this will not affect them, however perhaps there is some repulsion due to electron fields which would prevent most of the atoms from getting close. The other fundamental force in play is the strong and weak nuclear force (gravity is negligable at this scale). If the atoms came within 0.5fm they would massively repel but this is beyond nuclear scale, let alone atomic. I suppose if the atoms had a large enough energy, i.e. kinetic, potential or an associating high frequency (wave-like behaivour of particles) you would see large deflections, possibly defraction patterns. If two atoms collided at enormous energy then they could possibly fuse, but this can only really take place in stars where the force of collision is created by the intense gravity of the star in the core. TLDR: depends on their mass and energy",
"In what context? In a particle collider? This is very vague question that can't be answered without some more from you on what exactly you're asking.",
"99.99999% of the time- absolutely nothing other than some kinetic energy is exchanged, one atom bumping the other and their movements affecting each other. For anything interesting to happen, they must be collided together with immense force and pressure. For the atoms to touch (and this is a very wide generality), we’re talking the rough energy of a fast baseball pitch. PER ATOM PAIR. If they hit hard enough, they can fuse, releasing massive energies by the breaking of bonds of the strong nuclear force. This is what powers the sun."
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ny4dbq | Why do you usually feel so much better after throwing up when you feel nauseous? | Biology | explainlikeimfive | {
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"Because that's the point of vomiting. To get evacuate the contents of your stomach because the body thinks it has detected something harmful in there.",
"You do? I feel like I've vomited, and then I’ll probably vomit again multiple times because I can taste vomit. Not to mention the burning acid through my mouth and nose and throat. And then when I think I'm done there will be some piece of post nasal drip (aka vomit chunk) that dislodges itself and starts the cycle again. When I do eventually stop I feel horrible and drained, and like I've been run over by a truck. No sir I do not enjoy vomiting. 0/10, do not recommend. But 2 days later, sure, I feel better.",
"I’ll add another. If you’re exhausted and puke it’s because you’re body determined that it didn’t have the energy for digestion and what you were doing. Sometimes that can be hiking or exercise, or sometimes it can be fighting an infection. You’ll often feel more energetic because you’re not digesting food anymore.",
"Ever had puke stuck in your throat and you can’t breathe? That’s the worst. It subsides shortly though."
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