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why are wind turbines giant 3-wing fans as opposed to other designs such as a rolling cylinder or even multiple smaller fans/cylinders?
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"Bigger systems take more material, and have more weight requiring stronger supports which increase cost.\n\nThat, and you waste energy spinning up a heavy turbine, so the three turbine design minimizes those concerns while trying not to sacrifice the ability to harness the wind.\n\nBut those other designs do exist and are used."
] |
How did UDT navigate dark waters when visibility is nothing?
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"Most of the time they did dead reckoning. That is to say that they went in a straight line until they either hit something or until they figure they have gone far enough. This did actually work sometimes but at least it brought you closer to your target. They would also pop their heads/periscope above the water for a few moments to try to find recognizable landmarks that they could use to navigate. Even if it is completely dark you might have some light when your eyes have adjusted. You might use the light from the moon or the stars to both orient yourself and to spot landmarks. Houses and cars might have some light on them which is easy to spot in the dark or use as light to see other landmarks. Guards also tend to smoke on duty which gives off tiny spots of lights that can be seen for some distance. Then it is back into the dark depths of the water and continue on dead reckoning towards the intended target."
] |
Why do generators and electricity in general make a buzzing sound?
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"Alternating current is used for most electrical transmission, and it's also in the walls in your house. The North American standard is 60 Hz, which means that the current alternates 60 times per second. When you hear a hum - the mains hum - it's either caused by magnetic fields from the wires causing the metal of the generator to vibrate, or it's caused by the wires in your speakers picking up the electric current in nearby power wires.",
"In addition to the 60hz sounds, if you are on an aircraft you may notice a higher pitched whine, particularly when the captain or flight attendant is speaking to the cabin. \n\nThis is because aircraft use 400 Hertz a/c power. This allows smaller and lighter transformers to be used.",
"Electricity in general does not make sound. Generators make lots of noise due to the engines that drive them. Transformers can buzz due to an effect called [magnetostriction](_URL_0_). It results from changing magnetic fields. High current cables in metal conduit can vibrate. High voltage lines can make noise due to corona, which is ionization of air."
] |
Is urine beneficial or aggravating to jelly stings?
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"this is one of those cases where someone heard a fun factoid, and spreads it round without context and it now becomes a widely recognized \"myth\". There is a specific composition of urine that would work for specific types of stings but the chances that your/someone elses pee on the jellyfish that stung you would be a match is very very very low. For the times where Urine does not how, it can actually cause the stinger cells to release more toxins which is what causes the pain sensation. The pain lasts a long time because your body has its own natural defense mechanism but it doesn't work as fast.\n\n & #x200B;\n\nThis is kind of like someone saying \"i kicked my tv and it turned on again\" maybe in very few cases that your kick shook something loose back into place but more likely than not you would do more damage than finding the right tool for the job.",
"Do NOT pee on a jellyfish sting. This is a myth that just won't die. Peeing on a jellyfish sting can actually cause the stingers stuck in your skin to sting even more. Vinegar is generally useful to deactivate the stingers of most species of jellyfish. General first-aid is to use vinegar to to deactivate the stingers and then remove them with tweezers. Then you can use topical hydrocortisone cream or an oral antihistamine to control swelling and otc pain relievers as needed."
] |
Why is seawater green in some places, and clear/blue in other places? And why dont these colors mix?
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"Green sea water is usually the presence of floating algae, diatoms and other plankton that feed on the nutrients in the water. Green water has more stuff alive in it, usually colder water. Colder water can hold more dissolved oxygen in it. Often colder because of upwelling of deeper nutrient rich water that's being pushed to the surface by underwater geological features. \n\nTropical water tends to be clear/blue because it's warmer and therefore has less oxygen and have less nutrients, therefore less microscopic aquatic life.",
"Algae. They do mix, water can be varying shades of green/blue and have varying opacity. Cold water from springs or from snow melt is a lot more likely to be clear because algae don't like cold water with strong currents. If you follow that same water downstream to a lake at a lower altitude, you will probably see more and more algae bloom. Glaciers also often deposit 'rock flour' into the water, which is just a bunch of minerals from the rocks that they erode. This is why glacial lakes have that surreal aquamarine color."
] |
How can earthquakes be "predicted"?
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"Short answer: They can't be predicted, only detected. \n\nMedium Answer: You can sort of predict them on geological time scales (i.e. hundreds, thousands or millions of years) based on past patterns of earthquakes, but it makes predicting the weather next year look simple and reliable.\n\nLong Answer: Monitoring stations all over the world exist to detect seismic activity (and nuclear weapons, but lets ignore that here). Sometimes earthquakes seem to come after a period of smaller tremors, but usually there is one major purpose for these sensors; giving a short warning. If you have a sensor very close to various faults or volcanoes, you can send a warning at the speed of light while the quake itself moves at the speed of sound through the ground. That can add up to almost no warning, or a lot of warning, but any warning is better than nothing. \n\nSome plans exist to use these systems, or others which sense faster initial waves, to automatically engage certain safety systems. Power grids would \"brace\" for impact, trains would brake to a halt, and traffic lights would go red, automated warning evacuation warnings would occur. Even then, in the best circumstances, you're talking about minutes and not hours of warning. \n\nThis is one reason why earthquakes are so dangerous, because while you can build to withstand one, you can't predict them accurately in terms of time or intensity (on the scale of a human lifetime or two at least).",
"Earthquakes give off several different kinds of waves. \n\nPrimary waves - the fastest wave, moves about 3 mi/sec in a horizontal motion, only causes slight movement\n\nSecondary waves - start at same time as primary waves but move at half the speed. Waves are vertical and horizontal. Cause light shaking.\n\nSurface waves - move much slower than primary and secondary waves but cause the most damage\n\nIf we can devise a means to quickly and accurately detect P waves then it could give people minutes notice before an incoming earthquake that can save lives.\n\nIf we can detect what happens to cause earthquakes then we could give even more notice."
] |
Why don’t our ring fingers have the same mobility as our other fingers?
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"[_URL_0_](_URL_0_) \nHere's how the muscles connect to our fingers, I'll refer to that in the explanation here.\n\n & #x200B;\n\nIf you look at the index, pinky, and thumb, you'll see that they have unique muscles attached to them that allow them to behave somewhat independently of the others. The ring finger doesn't, it uses the same muscle groups that activate the other fingers, so trying to get it to do something unique while the others are moving is just about impossible. \n\n & #x200B;\n\nThere are exercises you can do to better control the ring finger, and musicians really enjoy these kinds of exercises because they give them better control over their instruments.",
"ELI5: How's ring finger not as mobile as other fingers?\n\nI tried bunch of things with index and ring finger and I can't find any task where ring finger would perform worse.",
"Because that is how humans evolved. Either there was never a mutation that lead to a separate muscle for controlling the ring finger, or maybe there was but it didn't give enough of an advantage that it propagated through the population. Maybe it did but there was some natural disaster that wiped out the population that had the mutation.\n\n & #x200B;\n\nWhatever happened, humans didn't evolve to have the complete independent control of the ring finger",
"Guitarist here. I looked into this years ago. It has less to do with muscles than it does with tendons. You notice, if you flex your hand and look at the back of it, there are three tendons for four fingers (the thumb is on its own). Your ring finger and pinky use the same tendon. You can bend your ring finger without bending your pinky, right? Now try bending only your pinky at the middle knuckle and notice that the end of your ring finger bends as well. This is because of the shared tendon. One seems to be more dominant. My guess is that the pinky is becoming less important from an evolutionary standpoint. We use it the least. That's just a guess. \n\n\nI only looked this up after a boxer's fracture on my left hand which made it more difficult to use my pinky. I can't say I understand the complete reason, but I know it lies in the tendons. Doctors who specialize in hands (no idea if there is a certain name for them) explained that to me."
] |
Why would a senator vote against the permanent funding for 9/11 first responders?
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"The bill was voted and passed 97-2. \n\nThe two senators who did not vote yes on the bill (Rand Paul and Mike Lee) both proposed amendments to the bill which were shot down quickly and the bill passed.\n\nRand Paul was doing obvious grandstanding quite a bit saying the bill is fake furor over a problem that has already been addressed (there are other bills already in place), and that the amount of money spent on this particular bill needs to be offset by other cuts, because the cost is too high and he doesn't want to increase spending/debt.\n\nPaul Lee proposed a similar idea to limit the cost, which was also rejected.\n\nAlmost certainly, they voted no to get political attention and well, they certainly are gonna get attention from it."
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Body fat?! How does it dictate its destination??
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"Fats you ingest are broken down in your body into glycerol and fatty acids using secretions from your fall bladder and pancreas before it is absorbed through the intestinal lining into the lymphatic system. The lymph system delivers the reassembled fat packages to veins near the fats destination. The fat packages are broken back down into fatty acids and glycerol in the bloodstream so that they can easily pass into cell membranes. \n\nAfter that (extremely shortened) crash course into how far gets into cells, I can answer your question. \n\nFat doesn't dictate its own destination. Sex hormones do! Testosterone in low levels encourages fat to be absorbed into adipose cells (fat cells) in the belly and estrogen encourages fat to be stored in the hips, buttox and legs. Sex hormones don't directly control where fat is absorbed, but they trigger other hormones that tell fat cells to absorb fat. \n\nThe distribution of fat cells is controlled by sex hormones during development. When these signals are sent out for fat cells to absorb fat, because there are more fat cells in certain areas, these areas absorb more fat in total. \n\nWhen a person gains weight, the fat cells get bigger, the number of fat cells does not increase. Where fat cells are created in development controls where a person stores fat. \n\n\n\nTldr: fat doesn't decide. In development, higher numbers of fat cells develope in different areas based on sex hormones I'm development. When the signal saying \"store extra fat\" is sent out, the most fat is absorbed into areas with more fat cells."
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Is it possible that dinosaurs could exist on another planet like Earth
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"Technically possible but extremely unlikely that another planet would have nearly the same conditions and evolutionary path that would lead to dinosaurs existing. Actually, it's so unlikely that it is almost impossible."
] |
What is that feeling called "when a vehicle beside you is moving, but you’re stationary, however for a brief second it feels like you’re moving if you look at the other vehicle and why does it happen?
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"A lot of the data your brain uses to control balance is visual. Try walking a balance beam with your eyes closed. \n\nThis phenomenon happens sometimes because your brain doesn't realize that the object it is using as a stationary frame of reference for your movement, is itself moving. Your brain really thinks you are moving backwards and can trigger the sensation. That's why this happens more if you are not paying attention to what you're looking at, and the car is a large portion of your field of vision. Without another object to tell your brain that the car is actually moving, for a split second it assumes you are rolling backwards.",
"Did anyone else stand on the shore as a kid and look at your feet as the sea rushes back out over them so that it feels like you're moving backwards??",
"It’s also one of the prime examples of “relativity.” You’re perception of an event is relative to your perspective. With the vehicle, you’ve lost the visual queues to tell you if you or the other vehicle is moving.",
"Whatever it's called, I like to start driving out of a parking spot just as someone comes to a stop on the spot beside me... hoping they get this feeling, whatever it's called.",
"IIRC it's cause by cognitive disassociation. Basically your brain see's the movement, assumes you are the thing moving, and just goes with it for a moment. I think this is the premise/cause of motion sickness, just instead of you moving and seeing something stationary.",
"If someone pulls up next to me at a light, I like to creep forward starting the moment they stop so they think they are rolling backward. Bonus points if you see them stomping at their brake pedal to keep from rolling back into the person behind them.",
"Or the extended situation when in a stationary train in a station as the neighboring stationary train leaves the station."
] |
- Why is some lightning not accompanied by thunder?
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"It is just lightning that is too far away for you to hear the thunder. It takes the right atmospheric conditions for you to see it. It is often called \"heat lightning\" but there is nothing different about it.",
"I’m having the exact same thing in the southeast. I get flashes of lighting then either a really small rumble or nothing. This could be because we’re just far from teh center of storm."
] |
zoning out on drives
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"I will defer to a [previous answer](_URL_2_) to this question, courtesy of u/coriolinus.\n\n > Driving is not an intense task. Once you're used to it, it is almost as simple as walking; you simply do not need to actually think about most of what's going on. \n\n > Memory is triggered by novelty. If you see something new or interesting, you are more likely to remember it. Conversely, if you see something you've seen dozens of times before, unless something unusual happens you are unlikely to remember it. A person who drives 10000 miles per year, and has done so for the last decade, will have in that time spent around 2500 hours on the road. Truly novel experiences on the road will be very rare.\n\n > In short, you are probably paying all necessary attention to the road as you drive. However, you don't bother forming memories of the experience because you have done it all before.\n\nOr [another](_URL_1_) by u/dfoley323\n\n > You\\[r] brain will tend to 'zone out' on certain tasks that are done over and over again. Basically it tries to minimize sensory over stimulation.\n\n > That's why you can remember an event (Omg a car just ran the stop sign and almost hit me), but you might not remember the make/model/LP unless you are trained or conditioned to force yourself to remember these details.\n\n > For someone who has been driving a lot, most of what you are doing is basic motor functions; scan the road, move the steering wheel left/right to keep inside the line, follow the speed of the car in front of you. This is also why non aggressive driving people tend to run red lights.\n\nAnd [another](_URL_0_) by psychologist u/\\[deleted]\n\n > Psychologist here. This happens for essentially the same reason that you Can \"zone out\" while you're walking around, not stumbling or colliding with things. These tasks are called \"steriotypic repetitious movements\" and they are actually controlled by a different part of the brain after you've fully learned the skill! When you start to learn any skill, like riding a bike, your cortex is the part of the brain doing the work of figuring out how to coordinate your muscles appropriately. Its complicated at first, and it involves your full attention, just like when you learned to walk. However, over time your cortex figures out exactly which muscles need to coordinate in exactly the right way, and it basically \"saves\" that motion in memory. When you go to do that action again after its already been learned (or saved) a cool thing happens, the cortex isn't nearly as involved anymore, now it's more subcortical (aka below the cortex, so deeper in the brain) regions that control the movement. The result? Now you perform an action while your cortex is free to think (or not think and \"zone out\") and forget you're actually doing anything complicated at all.",
"Micro-sleeping\n\n & #x200B;\n\nYou just temporarily begin sleeping and you're unaware that it happened. Usually lasts between 30 seconds and 2 minutes. A lot of car crashes are caused by this, too."
] |
what does it mean by space is a vacuum
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"It means that a typical cubic meter of space has about 1 atom in it. The rest of it is emptiness.",
"A vacuum is an empty area. Usually physical scientists use it to refer to an area without any gas in it. Space has almost zero gas in it (not quite, but close enough as to effectively be the same most of the time). This means that a scientist would call space a vacuum."
] |
How does cardio decrease ones heart rate?
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"With extensive training, your heart will eventually get stronger and become more efficient at transporting oxygen to the rest of your body, meaning it'll require less pumps and lower one's heart rate.\n\nI dunno about the second question, though.",
"When the heart gets in better 'shape' the left side beat (the one that shoves the blood around the body) gets more efficient. It needs less energy to pump the blood and requires fewer beats for whatever load you put on it. It is really your entire circulatory system that gets more efficient. Plus, your muscles use the oxygen more efficiently thus requiring less blood. This is why cardiovascular activity is so critical to ageing well, it makes a bunch of systems work better. Including, and it should be screamed on PSAs, your mental health.",
"The more intensely you do something, the easier that thing will feel when you're not going so hard. For example, if you can squat 300lbs, surely squatting your body weight would feel like nothing, right?\n\nThe same goes for running - the more you push yourself, the easier it will be for your body to be \"normal\" because it is prepared to do harder things at some point.\n\nCardio would benefit people who have anxiety issues because it's a way to provide the body activity and distracting while benefiting you positively."
] |
If falling asleep at the wheel is such a big problem, why don’t people just pull over to the side of the road and sleep in their car?
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"Because the road isn't necessarily a good place to nap. To start with, the shoulder of most roads isn't terribly large. Even on a major interstate highway you've got basically just enough room to fit your car. Sleeping that close to other drivers barreling past you at high speeds, is not a safe decision. \n\nUp next, the kinds of sections of road where people tend to get tired, are relatively isolated. Falling asleep in your car, in the middle of nowhere can leave you in a fairly vulnerable position. \n\nFinally, this behavior is likely illegal in a lot of instances. Stopping on the side of the interstate for instance is a problem unless you're stopping for an emergency situation (broken down, etc). \n\nEven truckers stop at either truck-stops, or designated rest areas.\n\nEdit: If you find yourself in this situation, stop in the nearest town you can find. Find a McDonald's or a Walmart parking lot. They'll likely be friendly (my local Walmart in particular is good about letting truckers and RV's part and sleep, provided you go to the far-end of the lot, and don't cause trouble. This is the safest option for sure.",
"Nobody wants to sleep in a car, and especially not along the side of the interstate. Taking a nap in a car parked right next to such high-speed (and possibly also sleep-deprived) traffic is a brilliant way to make sure you never wake up. Not to mention, usually when people are driving tired, it is because they're on a tight schedule and can't stop to sleep. Ex: Truckers, road-tripping families..."
] |
How do our bodies decide where to burn fat from after exercise?
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"They don't really decide. The fat on the surface of each deposit is metabolized with fairly equal preference. This means that deposits with a higher amount of surface area will lose the most mass.\n\nEdit - In other words, it comes off in layers like peeling an onion. The top layer is burned wherever it is located on your body.",
"Fat is burned pretty evenly, but genetics and hormones can play a big role in where fat is stored. You cannot “target fat” from just one area of your body.",
"It doesn't!\n\nHowever, visceral fat is burned first. Because it's closer and more connected to a large blood supply (organs) \n\nVisceral fat is also the most dangerous fat to have.",
"To complicated for a Reddit comment, but if you want to dig deep, look into how catecholamines mobilise fat cells for energy.",
"There is basically two types of fat: Subcutaneous and visceral.\n\nSubcutaneous fat is the fat that is on your arm, legs, butt and face.\n\nYour body will first burn subcutaneous fat, then when you have burned most of the subcutaneous fat, your body will start burning visceral fat (belly fat and fat around your organs)\n\n & #x200B;\n\nWhy? For various reasons your body is programmed to use visceral fat as a last resort. The main reason is that your body needs a small amount of visceral fat to function correctly but subcutaneous fat is entirely optional.\n\n & #x200B;\n\nThat s why it s so hard to get rid of belly fat, you first have to burn through your subcutaneous fat. That s also why when you do a regime, your face, arms,legs will loose fat first, then your belly."
] |
Why do scientists assume water is necessary for all life on other planets? Is it silly to assume there might be other organisms that don’t need it to survive?
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"It's possible... Someone with more expertise can correct me on this, but water is just really useful, and is also a good marker of temperature. For one thing, it can dissolve all sorts of things. Like... especially with a little bit of the right additives it can dissolve darn near anything. Ex: Water with hydrogen chloride and nitric acid dissolved in it can even dissolve gold. This ability to dissolve things allows water to activate acids and bases, as well. Water is often called the \"universal solvent\" because of this. Now, because it is dense and viscous (when compared to gases), as well as good at dissolving everything, water makes it much more likely that life will form in the first place; the first life on Earth was single-celled organisms in the oceans. Lastly, if water is liquid, it indicates a temperature range that allows carbon-based life to exist. Carbon-based life is life that uses long chain molecules held together by carbon. Such molecules are often unstable at higher temperatures, and lose many of their interesting properties at lower temperatures. This means that too-hot or too-cold regions would severely limit the number of molecules life could be made from, which would make it even less likely to form. All of this adds up to mean that life (as we understand it) will likely form in and around water."
] |
What actually happens when water “goes down the wrong pipe?”
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"It enters your windpipe, which leads to your lungs, instead of your esophagus, which leads to your stomach. There is a small flap/valve that decides which pipe things go down, and sometimes you don't move it fast enough, our you for some reason try to breathe while drinking. Your body doesn't like that, so it causes you to hack and cough a ton to try to get it back out. A small amount of water can remain in your windpipe and lungs for quite a while, so you will probably have a good cough every few minutes for a while after the initial swallow."
] |
When lightning hits the water, what happens to the fish?
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"There was a question like this earlier. Mostly, the fish don't care because the lightening spreads out and dissipates enough to be safe before it reaches them. A couple of 'em will die occasionally, but there are plenty of fish to keep the population going."
] |
why doesn’t a plane fall from the sky when it turns?
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"The plane will always produce lift approximately perpendicular to its wings. If you bank (rotate along the fuselage) the plane then the direction of the lift will rotate the same amount and no longer point directly upwards but rather point somewhat in the bank direction. This results in 2 things:\n\nThere is now a force pointing in the bank direction. The plane will move in the bank direction and fly a turn.\n\nThe lift is no longer directly opposite to the force of gravity and thus the plane will start to drop. If you want to fly a level turn (compensated turn) you will need to increase your lift by 1/cos (bankangle). You can do this by pulling on the stick during the turn.",
"Think of it this way: moving an aileron *reduces* the lift on one wing, so that wing drops, banking the plane. At the same time, the other wing is now traveling faster through the air, so has increased lift."
] |
Why do containers such as wine and beer bottles do the whole “glug glug glug” thing when being emptied?
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"Air displacement. When pouring a bottle upside down or covering the entire seal as it empties it creates a vacuum. The positive pressure from outside moves to the low pressure inside the bottle.",
"The glug happens as air enters the bottle. Basically if you tried to pull the liquid out without replacing it with something else, there would be a vacuum that would try to pull the liquid back. Since there is air surrounding the bottle and the liquid is much heavier and thicker than the air, the liquid wants to fall and the vacuum wants something to replace it. The air forces itself into the bottle to fill the vacuum but the thickness of the liquid prevents a constant flow. This causes bubbles of air to enter. The bubble pushes the liquid out of its way as it moves up the bottle and the liquid races to fill the empty space behind it. The liquid slamming into itself and the bottle creates a pressure wave that can be felt and heard as sound.",
"I'm assuming it's because of the air. Have you ever noticed something's such as coffee cups have a small hole, not only its it for steam but it allows air flow so that you can sip it. Where as if you tried to do that with a bottle, you would create a vacuum affect. So when you try to pour it the air gets trapped at the back of the bottle and prevents it from pouring gradually. When you pour it horizontally, the air flow allows it to pour with out gluging"
] |
What part of the brain is responsible for the 'internal monologue/dialogue' we hear in our minds?
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"Scientist have looked at brains using fMRIs and found the superior temporal gyrus and the left inferior frontal gyrus light up. \nThose are the areas that light up deal mainly with language. \nA bunch of other areas light up as well, a lot have to do with predicting what other people would do. \n \nTo put it to an analogy, it's a lot like GPU processing on a high end Computer. \nThere is some very expensive and very powerful specialized hardware installed. \nIt was meant to do one thing that was very difficult. \nBut in the process it turned out we could use that hardware to do some other things that were difficult.",
"My understanding is that the same pathways light up as if you were speaking the monologue, just without the actual speaking out loud part",
"I don't have one, so I volunteer to have my brain scanned to find out which bit is missing.",
"When that voice is totally negative all the time, it feels like depression. My therapist says it can actually cause depression. She calls it \"The shitty committee.\"",
"It is just like your eyes. Your eyes always \"see\", no matter what. Always turned on. They also \"see\" when you close your lids. Then they see darkness, but still they are looking. The same with your mind. As a long time practitioner of meditation I can tell you, the thinking never stops. You just have to get along with it. You cannot force your thoughts to stop (the good thing is, one always can think one thought after the other and there is a gap between the consecutive flow of thoughts).\n\nI am no scientist, but in Buddhism we say, thinking is the function of the brain as seeing is the function of the eye.\n\nEdit: typo",
"Although every part of the central nervous system contributes to your \"Self\" by how it affects you on a neuroligical level it is likely the pre-frontal cortex that contributes the most by putting it all together.",
"Others have answered where the internal monologue comes from, but nobody has explained why it may be so vivid. Cognitive neuroscience has come out with several explanations, but this one is one of my favourites. \n\nWhen we plan an action, this sends a signal both to our motor system for the action itself, and to our sensory system. That way, we know what sensory information to expect when we enact that action and can correct for mismatches. For example, when we send a signal to step down the bottom step of a staircase, a signal gets sent to your leg, and to our sensory system so we know what that will feel like once it happens. When something goes wrong, for example, we step down and we’ve run out of steps, there is a mismatch between what we expected to feel and what we actually felt, and the brain autocorrects for the mismatch so you (hopefully) don’t crumple into a heap on the bottom of the steps. \n\nThis signal has been shown to apply to speech as well. We autocorrect for errors in our speech this way. So planning speech and internal monologue seems to actually be represented in the sensory system in this way. In fact, there is a hypothesis that this pathway is broken in some people, and that this may be a factor in auditory hallucinations. We are still sending the signal to our sensory system, but the part that tells your brain “this is coming from our prefrontal cortex, not outside” may be malfunctioning. It could explain schizophrenia’s hallmark ‘voices in my head’.",
"There is an area in the brain called the Wernicke area that is used mainly for the processing of speech. There is a different part of the brain that controls actually producing the sounds needed for speech. Basically the \"international thinking\" that is usually reffered to as our \"voice\" is produced by the Wernicke area."
] |
If the moon moves 1.6 inches every year away from earth, and is 4.2 billion years old, why is the moon not MUCH farther away?
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"Well, if it moved at a constant rate of 1.6 inches per year, after 4.2 billion years, it would have moved about 106,000 miles.\n\nIt's current distance from the earth is about 240,000 miles, so 4.2 billion years ago it would have been about 130,000 miles away.\n\nAs it happens, the rate at which it's drifting away is actually slowing down, so it was probably closer than that.",
"This is the tweet of Neil deGrasse Tyson: \"When the Moon first formed, four billion years ago, it was 20x closer than it is today, 400x larger on the sky, and Tides were 8,000x higher. \nCLARIFICATION: Tidal forces scale as the cube of distance. That’s how you get the factor 8000 = 20 x 20 x 20. No oceans yet on Earth 4-Billion years ago, but there are also crustal tides of the solid Earth, rising 8,000 times higher than the 15 inches it rises and falls today. \"\n_URL_0_"
] |
Why do you see colors and distorted shapes when you have your eyes closed?
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"When you're eyes are closed, your retinas are still sensing even though they're not actually seeing anything. However, the only type of data that your brain can receive from your retinas is visual input, so the brain puts an image to what you're sensing. (You see more wild colors and images when you rub your eyes while closed, right? That's your retinas sensing changes in pressure and your brain trying to read what they're sensing.)",
"They're called [phosphenes](_URL_0_). They're believed to be caused by electrical activity in the retina even when it's not actively \"seeing\" anything. They are normal.",
"Generally retina neurons are triggered by light, but they sometimes trigger for other reasons, one of them is pressure, if you squeeze your eyes for example you'll see more colours and shapes. Some light can also get trough eyelids, either straight trough the flesh or because you don't close them perfectly.\n\nAnyway, some neurons are always triggered. Vision isn't faithful, you don't see exactly what your retina senses, your brain does lot of processing. For example, each eye has a blind spot and your brain automatically fills it based on surroundings, there are also adjustments based on shade and colours (think of the famous blue and black/white and gold dress) and finally you have pattern recognition to pick up faster dangers, emotions and such (it's easy to see a face in two dots and a line, puppies are universally considered cute because of the head/eye/body ratio and so on).\n\nWhat happens is basically that your brain still automatically elaborates those random signals, finding patters that aren't there, resulting in shapes and colours."
] |
How do we know π is never repeating when could be just a really big series/pattern of numbers?
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[
"This is a bit complicated so I'm going to trh my best to break it down in a way that will at least give you something! I'm also not a professional mathematician (though I do have a degree in math). I hope this helps somewhat!\n\nIrrational numbers are numbers that cannot be expressed as the ratio of two integers. This means their decimal sequence never ends or repeats. However, there are two major classes are irrational numbers that are each a little different. \n\nThe first are [algebraic numbers](_URL_2_), which are numbers that are the solution to some algebraic expression with integer coefficients. All integers and rational numbers are algebraic numbers as you can simply construct an expression such as m*x=n, therefore giving you solutions of the form n/m where n and m can be any integer. However, what is really interesting to us here are irrational algebraic numbers. The square root of two is an irrational algebraic number as it is the solution of x^2 =2. It can be shown that this number is irrational quite easily by a proof of contradiction shown [here](_URL_3_).\n\nThe second major class of irrational numbers are known as [transcendental numbers](_URL_4_). These are numbers that do not satisfy any finite length algebraic expression, and so they can be thought of as \"transcending\" algebra.\n\nThe [Lindemamm-Weierstrass Theorem](_URL_1_) allows for a proof that pi is NOT an algebraic number. The proof essentially goes as follows:\n\n- First, it was shown the e^a (where e is the base of the natural log) is transcendental if and only if **a** is algebraic. (A sketch of this proof is shown [here](_URL_0_))\n- Euler's identity is used to show us that e^(i*pi) =-1\n- Because -1 is a rational number, then that means (by our first step) that i*pi is NOT algebraic.\n- i is the imaginary unit and is algebraic (it is the solution to x^2 =-1)\n- Therefore pi is not algebraic.\n- If pi is not algebraic then it must be transcendental, and so it is irrational.\n\nAn interesting thing to note though, is that even though pi is transcendental and thus has a never ending non-repeating decimal sequence, it has NOT been proven to be \"normal\". What that means is that we dont know if every digit appears with the same regularity. If pi isnt normal, then it means that even though it is never ending and non-repeating, there are sequences of digits it would NEVER contain. As an extreme example to illustrate this: imagine that at somepoint, a trillion trillion trillion digits into pi, it stops containing the number 5. No more 5's appear. The rest of the digits (0-4 and 6-9) still appear infinitely and non-repeating, but you'll never get another sequence that contains a 5. \n\nWhat this means is that those quotes claiming that pi contains every sequence of digits and thus contains the information for \"anything and everythjng\" aren't actually substantiated as of yet. If pi is normal then that would be true, however we just dont know! (And it should be pointed out that this property is not actually mysterious or unique. Most numbers are transcendental and normal. We just have a difficult time finding/proving them to be such because so much of our mathematical foundation is based around algebra)\n\n**TLDR:** The basic idea is that it is possible to show that the number e is transcendental as it cannot be expressed as the solution to a finite algebraic expression. By using ruler's identity, you can conclude that the same must also be true for pi.\n\nThis is rather complicated stuff.... maybe someone with more insight than me can give a better answer, but i hope this helped at least a bit! Let me know if you've got any questions about this.",
"The reason for why pi is not just a repeating decimal is well above 5 year olds, it's a proper ask science question. However, the just of it is that for a number to be rational, it must be able to be written as a/b where neither can be 0. If that fraction exists, the a lot a lot a lot of math breaks down. Since we have seen our current math be correct, then pi must be irrational.",
"We've proved that pi can't be a rational number, and since all non-rational (irrational) numbers never terminate or repeat, it means that pi never repeats.",
"There are two properties of every number that are equivalent:\n\n1. Can it be written down without any repeating patterns?\n\n2. Can it be written as one whole number divided by another?\n\nNumbers that can’t are called “irrational”. When proving that a number is irrational, mathematicians usually focus of the whole number dividing aspect. \n\nThe actual proof that pi can’t be written as one whole number divided by another is very long and difficult to follow. The proofs generally go like this:\n\n1. Assume that pi is equal to a/b where a and b are whole numbers and reduced to their lowest form (i.e. the two numbers are the smallest ones that equal pi like this).\n\n2. Do a whole bunch of algebra. \n\n3. Show that the algebra has proven something false, such as finding another pair of numbers smaller than the first pair that are also equal to pi when divided) or that one of the numbers is equal to 1 (it is obviously not 1). \n\nThen you say, we assumed something to be true, and that resulted in a contradiction. Therefore the thing assumed to be true must actually be false. Therefore pi cannot be written as a/b. Therefore pi is irrational. Therefore it’s decimal form will be a never repeating pattern."
] |
What is code and why is a lot of it in 0’s and 1’s?
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[
"This is a really complicated question, but I'll try to answer it as briefly as I can.\n\nYour computer is very much a kind of electrical machine, that manipulates the voltages of different wires, and is designed to preform calculations on those voltages. Scientists realized pretty early on in computer science, that a simple cost effective way to build computers was to use only two different voltage levels to represent different values, a high level and a low level.\n\nWith just two voltages, you can represent numbers by encoding them into a number system called binary. In binary, we use the number 0 to represent a low voltage and 1 to represent a high voltage. With just one digit you can only have two numbers 0 and 1, but if you have more digits then you can have bigger numbers. In binary 0, 1, 2, 3, 4, 5, 6, 7... gets converted to 0, 1, 10 (we added another digit for 2 because we ran out), 11, 100, 101, 110, 111...\n\nOnce you can represent numbers in a computer, you can store other kinds of data by mapping the numbers to a code. For example if you want to represent the alphabet, you could make 0 a space, 1 the letter a, 2 the letter b, and so on. It's a code because the numbers represent something else, like letters.\n\nYou can also represent computer instructions in a code (called machine code) and then you can design chips that read that code and execute those instructions. A chip that does this is called a processor, and the instructions it runs is called a program.\n\nYou can also represent letters, and this kind of code is called an encoding. ASCII and ANSI are some simple encodings that you can use for English, and UNICODE is an encoding you can use for any language.\n\nYou can also write letter codes that convert to machine code. This kind of code is called an assembly language, and a computer program that converts assembly to a new program is called an assembler.\n\nYou can also write more complicated codes that you can use to create programs. This kind of code is called a programming language, and there are thousands of different programming languages with different levels of complexity. If someone says they are a coder, they probably mean that they write computer programs in a programing language.\n\n & #x200B;\n\nThe 0's and 1's in the machine, by themselves are totally meaningless, and it's the machines ability to read those numbers as machine code, process those numbers with computer programs, or to convert them to a different format with encodings that make them useful. The computer can also just read them as binary numbers if it needs to, but binary is still a 'code' of sorts (called a number system) that converts those high and low voltages into numbers.",
"Zeros and ones are actually binary code and represent an on or off electric pulse, yet computer languages like Python3 or C++ aren't written in binary but in a human \"readable\" / \"writeable\" language. A little much to explain it like you're five. Pretty complex. That's why grade school kids usually start with something simple like scratch.",
"Code simply means \"language\". There are countless computer languages. 0s and 1s are what's known as \"binary\". That's the most basic language there is. Yes or No. On or Off. Simpler than your DNA which is made up of A, T, G, and C.\n\nAnother way to look at it: computer languages are like atoms. They come in all shapes and sizes. They make the things around us. But they're not the smallest things there are. In an atom, protons and neutrons are made up of quarks. There's an up quark and a down quark. Much as there is a 0 and a 1. All computer codes can be simplified or broken down into the most basic state of binary.",
"A code is just something you want to express written in another way that only those knowledgable can understand, in this case you are giving the computers a set of instruction in a way computers can understand. 0 and 1 represents gates which controls if information gets through. With 0 and 1s you tell the computer which gates to open, which gates to close, and then you run the code to see what spits out the other side."
] |
Why do companies buy our information and how is it valuable?
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[
"Same answer to both questions - because they want to sell you stuff.\n\nComputer software has advanced to the point that crunching enormous piles of data and getting real actionable insights is pretty easy. As an example - Target's analytics were so good that they started sending maternity oriented coupons to a 16 year old girl. Her father sued the company... only to find out that the girl was in fact pregnant. *They figured it out just by looking at what she was buying.*"
] |
what makes leopard and jaguar different
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[
"Elephants are the only animals of their kind, leopards and jaguars are not the only animals of their kind, they are part of all the big cats. Elephants are so similar that all are called elephants. Leopards and jaguars are actually not as similar as you think, they just happen to look the same.",
"They do share one name. \"Panther\" is a term that includes a number of big cats. But more than that, only jaguars and leopards have members with the melanistic variation that makes them appear almost entirely black. So in Africa and Asia, \"black panther\" refers to leopards, and in the Americas, black panthers are jaguars."
] |
What major changes would occur if Earth started spinning at 25 hours/day? What about 23 hrs/day?
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[
"Welp, nobody else has answered so I'll give it a go - I'm no climatologist tho. It sounds to me like you're asking specifically about how such a change would impact *climate*. With a slower spin, days would get hotter, and nights would get colder. It would be gradual, but the more you slow the earth the more you ruin farmland. These temperature extremes would force rapid adaptation on ecosystems and the life within them, and anything that failed this trial by fire would die. If I had to guess, I'd say that this would begin to happen within an extra 2-3 hours on a day, but I really don't have any good information to judge off of. Every creature with a circadian rhythm would be very confused, as well, since we're used to a particular length of days. If the Earth sped up, the opposite would happen. Day and night would get more similar temperatures. The Earth would probably heat up slightly. That's all I can think of tho."
] |
Where did the original vinegar "mother" come from, if you need vinegar to make a "mother"?
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[
"Vinegar is Latin for “sour wine.” All you have to do is let wine go bad under certain conditions and you’ll get a mother eventually.",
"Vinegar is wine that has spoiled and gone sour in a somewhat controlled way that leaves a product that is still safe to consume. You do not need a \"mother liquid\" to make it. Using a mother liquid simply makes the production of safe vinegar easier and you get toxic batches less often.",
"There's nothing magical about the mother, it's just the biofilm byproduct created by acetic acid bacteria fermenting alcohol in the presence of oxygen. Acetic acid bacteria are *absolutely everywhere.* Leave some wine out for long enough in the right conditions and you'll have your own vinegar, complete with a brand new mother, because acetic acid bacteria will get in and start fermenting. Using an existing mother is just a faster way to get the process going."
] |
If two separate plant's light sources are exclusively lightbulbs of equal lumen outputs but one bulb is LED and the other is incandescent, will they both photosynthesize / grow at the same rates?
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[
"From a quick google. Yes leds can be used as grow lights. They’re actually beneficial because you can customize the “spectral intensity” to suit different stages of growth.",
"It depends on how you are setting up your experiment. and incandescent bulb does not emit the same amount of light at each colour than what the sun would, and what an white LED would. i would like to point to you [here](_URL_1_), and specifically the graphs, and then here for the [absorption spectra of chlorophyll](_URL_0_).\n\nto help you digest, chlorophyll looks green because it likes to absorb blue light the most, and red/orange light next, leaving all the green light behind. Absorbing this light is what plants use as energy to grow. Now comparing incandescent bulbs to a white LED, we see that LEDs have some blue light emmisions, but the majority of light emitted is around green, so for the LED bulb a large portion of its energy is unused.\n\nCompared to incandescent bulbs, they emit very little blue light but more in the red to infrared sections of the light. although chlorophyll can absorb red/orange light, it is not very good at it.\n\nAll in all, i cannot comment on which would ultimately be better for growing plants, rather they will definately produce different results if you are only concerned with the intensity of the light."
] |
Why do Composite signals look so good on CRT's but utterly horrible on modern LCD's of the same size?
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[
"Because w/o having pixels, a CRT display isn't able to produce images as sharp as the ones shown by the LCD. The CRT smoothes the image and hides out some of the image defects, if there are. The pixels you can notice by looking closely to a CRT are just a regular pattern on the screen mask between the screen and the three electron guns."
] |
how come a camera can pick up light on a TV remote when being used but you can't see it with your own eyes?
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[
"Cameras use a different system to detect light than our eyes do. Our eyes use rod and cone cells and some weird chemistry stuff. Cameras use various systems - one example is photodetectors with filters over them to select for colors. This system is designed to replicate our eyesight's frequency range as best as economically possible. Emphasis on *economically*. To mimic our eyesight perfectly, the filters' frequency transmittance range has to match our cone cells' frequency sensitivity. The better this match, the closer the similarity a camera's picture is to what we see. Typically, they use the standard of \"close enough\" and call it a day. As such, a little bit of infrared light slips past the filter, and the camera sees it.",
"Our eyes only see a certain part of the light spectrum. There's a lot more to that spectrum, such as infrared and ultraviolet, that we can't see, but we can make cameras that are able to detect that light.",
"Most people don't actually know this. It is a good way to check if your IR remote controls are working. Just point them at your digital camera and start pushing buttons."
] |
How do just a few satellites give the precise location of a million of connected devices at the same time?
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[
"Each GPS satellite just broadcasts where they are, and what time their clock says. That signal can be picked up by any number of devices that have line of sight to the satellite.\n\nThe devices can then determine their position by trigonometry. Radio waves travel at a constant speed, so if you pick up a signal, and you know when the signal was transmitted, and what time it is now, you can determine the distance to the transmitter. With multiple signals from known locations, you can determine your own position.",
"They don't.\n\nThe satellites just know when and where they are and broadcast that information to everyone who will listen and your gps device uses that broadcast to figure out where it is itself.\n\nThink of it like a lighthouse beacon telling ships at sea where they are. The lighthouse has no idea where the ships are and isn't really aware of the ships, but the ships can see the lighthouse fire and figure from that where they are (near the lighthouse).\n\nGPS is not two way communication. It is just satellites telling everyone who will listen about their location in space and time and the listeners comparing the signals from several satellites and doing some math to pinpoint their own location.",
"There’s an internal log of the orbits of each satellite called an almanac that tells a GPS where the satellite is supposed to be at any time. Each satellite sends a time stamped signal that all GPSs with direct line of site (usually excluding the first 6 degrees or so above the horizon) receive. By comparing the time taken for the signal to be read from each satellite you can, this is for visualisation purposes, draw a sphere round the position of each satellite at the appropriate diameter, calculated by timedxspeed of light and where they all meet is your position.\n\nSatellites aren’t always precisely where the almanac says they should be so where you should theoretically only need 3, as in radio triangulation, you generally need 5+ to get a decently corrected position.\n\n:bonus: you usually exclude anything below about 6 degrees to eliminate too much delay due to atmospheric interference or refraction of the EM signal carrying the time stamp which screws up the math as the ratio of air to vacuum changes the speed of light enough to give a false resolution.",
"The devices aren't really connected, they are just listening. The GPS satellite is constantly yelling toward the ground the same thing: where it is and what time it is. The devices on the ground listen to several of them and triangulate their position by understanding the delay of each signal relative to the other signals, in relationship to the stated position of each signal."
] |
How has Jupiter’s red spot been such a large and powerful storm for centuries?
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[
"Storms are sustained by the conditions of their environment and the spin of their planet. So long as the planet keeps spinning and the conditions stay (normally, a hot center and cold exterior), the storm continues.",
"Take a bottle cap and spin it like a top, flat side down, on a smooth, hard surface. Now do the same but on the surface of some water. Notice how the bottle caps spins longer when floating on water? This is because the water has less friction so it doesn't slow down the bottle cap as much. \n\nThis is why hurricanes usually don't reach very far inland. The earth creates more friction than the ocean, causing it to slow down and break up.\n\nJupiter has no solid surface, it's all gas for a thousand kilometers down, then the hydrogen becomes a supercritical fluid, acting as both a gas and a liquid. So there is nothing to slow down or break up Jupiter's storms."
] |
What part of physics (QED, GR, etc.) predicts the existence of different phases of matter?
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[
"The work on phases of matter exists in the mathematics of statistical mechanics, which is used heavily in solid state physics, condensed matter physics, materials science, and a lot of chemistry.",
"Phases of matter tend to fall under the domain of chemistry more than physics. When they *do* fall into the realm of physics, it is often unexpected. Superconductors, low-temperature physics, high-temperature physics, astronomy... Generally really extreme contexts and edge cases. This isn't a particular domain of physics, per sé."
] |
How does this image have lines from the TV on it that change depending on zoom?
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"It is called a [\"Moire pattern\"](_URL_0_) and it happens when two regular patterns don't sync up leading to patches of interference. This is very common when taking pictures of digital displays as the pixel grid of the display is unlikely to match up with the pixel grid of the image capture device."
] |
why Americans are more used to air wents on a floor for heating their homes and Europeans are using radiators and floor heating?
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"We do also have floor heaters and radiators if it’s an older home, but since have moved to forced air systems. Cooled and heated air can move through the same vents to get to the rooms from the unit. Since the units are usually in the basement imagine the system being a trunk of a tree, and the vents are the tips of the branches coming off of it.",
"American buildings do use floor heat some, but air conditioning is much more common in the US which makes forced air more practical."
] |
How do some animals, such as scallops and clams, function without organs?
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[
"Your premise is totally wrong. Scallops and clams absolutely [have organs](_URL_0_). Even if you weren't wrong about, there are still other organisms without differentiated organs. I mean, all bacteria have no organs. They're just single cells. Less complex life forms don't need specialized organs for things, so their anatomy is likewise less complex. A jellyfish is basically just a floating sack of water. It has only the most rudimentary nervous system, a stomach, and a sex organ, because that's all it needs."
] |
How can something be 46 billion light years away from Earth, When the age of universe itself is 13 billion years?
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"The universe is expanding faster than the speed of light.\n\n[This video](_URL_0_) goes into how the universe can expand faster than the speed of light and personally I find it easy to follow.\n\nThe basic explanation is that the speed of light limit does not apply to the expansion of the universe.",
"The universe is expanding faster than the speed of light, and it’s also expanding in all directions. Think of a balloon, and you’re on the surface of it. Someone blows it up and you’re a meter from the middle of its inside (where the Big Bang/inflation started) but the opposite edge of the balloon would then be two metres away. Thinking diameter rather than radius. Not a perfect analogy but it’s what helped me understand it.",
"Imagine that the Earth is a giant balloon and is continually expanding, getting bigger everyday (this is the expanding universe analog). Now imagine it takes a mail carrier a day to deliver a letter one mile (this is the finite speed of light analog). \n\nA friend 10 miles away sends you a letter. Ten days later you receive it, but by the time you receive the letter your friend is now further than 10 miles away because the Earth is bigger, having inflated during that 10 day travel time.\n\nThe further away your friend is when they send you a letter, the longer the letter is in transit and the larger the Earth has expanded during that transit.",
"First off one is a measure distance (47 billion light-years) and the other age (13 billion years). However I think the OP is asking how can we know about something that is so far away that it would take light 46 billion years to travel from it to us when the universe is only 13 billion years old.",
"An object that we see that looks like it is 13 billion light years away was actually much closer to us when it emitted the light we're now getting. Because it was moving through expanding space the whole time getting to us, it took longer than the original distance to the object suggests it ought to have taken. However, because it was constantly getting closer to us, the effect the expansion had on it's arrival time was less and less over time. So, we now see it as if it was 13 billion light years away but it's actually much further than that now.\n\nSo basically, the furthest things we can see in our galaxy were much closer to us when the light we're receiving was emitted, and are now much further away than they appear to be, all due to the expansion of the universe.",
"Early in the development of the universe space expanded very quickly. The light that we see has traversed less distance than the locations are away from us now. Light can only move across space at a set speed, but there is no such limit on the amount of distance which can appear between two points.\n\nThis means that we can see light from places that are now far more distant than that light has had time to traverse (because it started before that space existed)."
] |
Could Queen Elizabeth refuse to accept a Prime Minister? What would happen if she did so?
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[
"The Queen has to decide whether the proposed new PM \"commands the confidence of the house\" i.e. could the PM lead a functioning government. \n\nThe Queen can quite legitimately send the proposed PM away if she thinks that a functioning government is not possible, but in reality this will never happen because: \n\n1. The decision is made before the new PM goes to Buckingham Palace, the Royal Household will be kept informed of what is going on so the process won't go ahead if there is any doubt.\n\n2. The new PM is \"invited to form a government\" so they have time to go away and sort out the details. In 2017 this involved Theresa May negotiating with the Democratic Unionist Party to get a theoretical majority in the House of Commons. In 2010 it involved the Conservatives leading a Coalition with the Liberal Democrats.\n\n3. There is a very high risk of a constitutional crisis if the Queen actually exercises this power. In reality she knows that a non-viable government would be brought down by a vote of no confidence in the House of Commons. This is the proper way to resolve the situation. \n\nUltimately Parliament is sovereign, the Queen is an important part of the process, but if she tried to interfere then it would bring about a national crisis."
] |
how do ads load on bad service but normal content doesn’t?
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"Youtube (through Google) have many, many servers across multiple regions of the world to store their data. Very popular content may be hosted on multiple servers to constantly have it closer to the viewer, and on faster servers.\n\nLess popular, more normal content will not necessarily be copied on multiple servers, or stored on very fast servers, making the video load more slowly. \n\nAds, on the other hand, will be stored in servers geographically close to you, and fast enough to always let them play as smoothly as possible."
] |
What is brain plaque and what can happen if it is not taken care of and how can it be prevented?
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[
"Alzheimer's disease involves amyloid plaque. No one quite knows why, although there are theories. [For some reason, amyloid protein breaks down and forms \"plaque\", which are blobs of goo that the brain can't remove.](_URL_0_) Alzheimer's also involves tangles of Tau protein, which is a structural support that gives brain cells shape. It isn't really understood whether the amyloid plaque or the tau tangles are the *cause* of the disease, or if they're more of an effect. Billions of dollars were spent developing and testing drugs that broke down amyloid plaque, they failed to help people with the disease. \n\n[The best thing to prevent it is sleep.](_URL_1_) Also, floss your teeth- [gum disease is lined to AD](_URL_2_) There are multiple hypotheses on how gum disease is linked to AD, and why it doesn't happen to young people with gum disease, but it is safe to say that flossing lowers the odds of developing brain plaque."
] |
Why is the magnetic North Pole moving faster than the magnetic South Pole?
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[
"I am not a geologist, so i will try an explanation based on physical and mathematical intuition:\n\nThe south magnetic pole (SMP) lies significantly farther away from the geographic south pole (\\~2800 km) compared to the north magnetic pole (NMP) which lies \\~600 km away from the geographic north pole. Given that Earth is an oblate spheroid, it doesn't have the same radius everywhere, it increases as we move towards the equator. This means that the SMP is farther away from Earth's core. The polar shift happens because of fluctuations in the flow of molten iron in Earth's outer core, which causes changes in Earth's magnetic field. Now the strength of a magnetic field is inversely proportional to the distance from its center. Less force is exerted to particles farther away from the center, therefore their acceleration and speed will be smaller. Thus the SMP shifts slower than the NMP.\n\nAgain, this is my interpretation and is open to debate."
] |
How does different spf’s on sunscreen (sublock) affect the tan you get?
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[
"It blocks the UV B rays which cause you to tan. The higher the SPF, the more it blocks the UV rays. \n\n_URL_0_"
] |
Why does metal bend but stone break?
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[
"Metals stay together more or less electromagnetically. All of the metal atoms are packed tightly enough their electrons are constantly switching around between them, which makes for a very strong, but also somewhat malleable material. There's not really any specific structure to them at the atomic level. \n\nRocks on the other hand, tend to have more crystalline matrixes. Their structures are sturdy but very specific at the atmoic level. These matrixes can't really change shape or reaarange themselves, so rather than bending, they break."
] |
Why Does English Have So Many Strange And Varied Collective Nouns For Animals?
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[
"> These just seem like jokes \n\nPretty much, yes. [Terms of venery](_URL_0_) are essentially an in-joke from the 1400s that happened to get written down. Some modern English speakers like them, most don't know about them.",
"There is no real point to it, it is as much a celebration of the sheer variety of the English language as anything else.",
"If you don't know the fancy word for \"a group of something\", you just say group. You can say \"I saw a flock of birds\" or you can say \"I saw a group of birds flying around\" or \"I saw a bunch of birds\" or \"I saw a lot of birds\" or \"I saw a shitload of birds\" or \"I saw a few birds\". All can be accurate, depending on how many birds there are and what they're up to. \n\nIt's interesting, because just saying \"I saw a group/flock of birds\" typically means the birds are all of the same species and have some kind of social connection. Whereas \"I saw a lot/couple of birds\" could mean you went to the zoo or the beach or the woods and saw several different types of unrelated birds, like a flamingo and a pigeon and a penguin and an eagle."
] |
How do synthesizers work?
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[
"A synthesizer can make all kinds of interesting noises. It does this with the help of modules.\n\nModules have inputs, outputs and sometimes also settings that can be changed.\n\nConnecting the outputs of modules to the input of (other) modules as well as changing the settings of those modules creates a 'patch'.\n\nA 'patch' is what determines how the synthesizer will sound and people will sometimes share (describe) their patches with other people so that they can also get the same sound. (Normally people need the same synthesizer to do this but there are exceptions.)\n\n & #x200B;\n\nThere are different types of modules;\n\n\\- An oscillator produces a signal that can be changed in shape (waveform), pitch (frequency) and volume (amplitude).\n\n\\- A filter takes a signal and changes how the signal 'sounds' by changing how loud or soft frequencies in a signal appear; filters make a signal sound warmer or colder.\n\n\\- A VCA takes a signal and makes it louder or softer with the help of another signal.\n\n\\- An envelope generator produces a signal that people use to create sounds that change over time; they are often used in combination with a VCA and/or filter to create sounds that 'imitate' plucked strings, brass instruments or percussion instruments.\n\n\\- and much more...\n\n & #x200B;\n\nTo summarize; Modules can be seen as building blocks that create, change or do things with the help of signals.\n\n & #x200B;\n\nIn modular synthesizers the modules are physical; you place them in a rack and use cables to connect inputs and outputs together.\n\n & #x200B;\n\nIn most synthesizer keyboards the modules are not physical and you use the screen and/or buttons to create patches.\n\n & #x200B;\n\nI hope this helps! (my first ELI5 answer, so it might need some editing..)"
] |
how a blister is formed.
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[
"Something causes a break between the layers of the skin - like heat that breaks connections between layers, or movement that mechanicaly tears it. The inner layers are living tissue, and so contain 'lumph'- the fluid that surrounds all living cells. This lymph pushes open that break made between layers, pushing the layers apart.\n\nThis is fine, however - left alone, the lower layer will seal over and become strong skin, the lymph will slowly be reabsorbed or leach through the skin, the top layer will dry up and flake off, leaving new, healthy skin. As long as the blister is left in tact.",
"So the structure of your skin layers is something like legos: you have ridges that fit together between the dermis and epidermis that keep them intact. Most blisters are friction or shearing injuries, meaning the epidermis is pulled in the opposite direction of the dermis and those ridges are disconnected forming a pocket. Part of the inflammatory process important to skin healing is moisture, so free interstitial fluid enters the pocket and fills it up. If a blister is left intact then the epithelium can eventually restick to the dermal layer. If it’s ruptured then the epidermis dries out and sloughs off, leaving exposed dermis with lots of exposed nerve endings and no protection.",
"Take a book or magazine, and imagine the pages are layers of skin.\n\nGently pet the pages, they don't move at all.\n\nNow hold press down on a page and move your hand back and forth hard, the pages will seperate and get damaged. That seperation is what causes a blister. The seperation can't repair immediately so your body fills the cavity with fluid.",
"Follow up question: if I pierce a blister with a needle, why does it reseal and refill after a little bit?"
] |
What decides the volume and duration of a thunder clap?
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[
"Imagine the soundwave/shockwave of thunder like an invisible cylinder around the lightning you just saw. That cylinder is created at the moment you see lightning, and it grows in radius at the speed of sound (approx. 300m/s). Now on the surface of that cylinder there are one thousand of tiny little surfers, each of the surfing in their own direction away from the lightning, and whenever a surfer collides with your ear, you hear a noise.\n\nNow, as the cylinder grows, all of the surfers naturally surf away from each other, and all the surfers grow further and further apart (or less and less energy per surface area). The less surfers reach your ear, the more quiet the thunder.\n\nThe duration of thunder is a little bit harder to imagine. Again, a thousand surfers riding the shockwave. In their path from the lightning outwards, some of the surfers hit rigid objects like walls, houses, rocks, or trees. These rigid surfaces reflect them away from their original path. But if they cross a city, they don't only hit one house, but many. They end up on sort of a crazy random walk through the city, reflected hundreds to thousands of times. But in the end they may still end up in someones ear, and that person can again hear a tiny noise.\n\nNow as I said there a thousands of surfers, and all of them are randomly reflected a different number of times, so they take a different amount of time until they can be heard. Hence the once short, loud bang (many surfers arriving all at the same time) became a long, less loud rumble (many surfers all arriving one after another).\n\nEdit: Gold? For a bunch of surfers? Thank you kind stranger!",
"What I don't understand is sometimes lightning is super bright and seems very near, and the thunder clap never comes, or is quiet. The brightness (and inferred closeness) of a bolt of lightning doesn't always seem to correspond to the volume of the thunder.",
"I’m not an expert, just a storm-lover and wanna be storm photographer. Can I add that if this topic is of interest to you, I HIGHLY recommend checking out _URL_0_. This is a fascinating way to enjoy a storm happening in your area, and it has a feature that shows the thunder sound front (or cylinder, to use the same verbiage as the previous poster) in *REAL TIME.*",
"The amount of air displaced, and your distance relative to the initial strike. \n\nLightning is so incredibly high voltage / heat intensive that it causes a sort of high pressure tube of super heated air. The air then rapidly expands outward. \n\nFrom 10-40,000 feet up, is how far lightning can travel. Even higher in some cases. That is an incredible distance, even just over 10,560 feet is two miles up into the atmosphere. So you’re talking about a lot of molecules that get pushed around in the disturbance. \n\nThe sound wave traveling out that we perceive as thunder is that movement of air. \n\nNow, your distance from the initial strike is important because sound travels in waves. Even one cubic foot of air displacement is audible to you. If you’ve ever been near one of those snapping glass domed Tesla coils, you’ve heard electricity in action. Just think about how loud it would be near the source of a strike thats 6 miles long!!? \n\nPeople have had their eardrums ruptured from less.\n\nThe wave form of the sound that you hear, follows the arc and path of the lightning, (Interestingly this also causes thunder to make that peal like effect.) \n\nThats why when you see lightning you can count before you hear thunder and it will give you a relative distance to the strike. (A game children learn to know when it’s safe to be outside during storms.) \n\nAs for full volume of it, volume decreases over distance. More air shifting in the path of the wave and echos bouncing back and around."
] |
Why do England, Wales, Scotland and NI compete in world cups but join together for the Olympics?
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[
"Many popular sports originated in the UK, so the first \"international\" competitions were between the nations within the UK.\n\nNow many other countries take part, but the idea that the UK nations compete separately has been grandfathered in. For example FIFA has an explicit rule that each of the four \"British Associations\" are members in their own right despite not being independent countries.\n\nHowever the Olympics involved many countries right from the start. So it was a team per sovereign state (more or less, some dependent territories have their own teams).",
"We had separate Football Associations for each country before any international body was set up so each joined as a separate organisation. Before distant foreign travel was easy, international competitions were between the Home Nations. The British Olympic Association and its predecessor the National Olympian Association was set up as a UK-wide body.",
"Basically the 4 separate FAs of England, Wales, NI and Scotland existed long before FIFA did and competed against each other annually in the British Home Championship. After FIFA formed and started the World Cup tournament they invited countries to compete in it based on existing FAs rather than what your passport says.\n\nIn the case of the Olympics Britain has always competed as joint team from the start, they registered to compete in the very first modern games as Great Britain and so it has remained."
] |
Equality vs Equity
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[
"Think of \"equity\" as \"fairness\".\n\nNow, imagine you are a teacher, and one of your students comes up to you saying they have cut their finger so you give them a bandaid. The next child comes up to you saying they have a headache so you give them a bandaid. Another student says they miss their parents, so you give them a bandaid. \n\nYou gave the exact same thing to every child in need (equality), but only one child was actually helped. It was unfair treatment even though it was equal. \n\nEquality doesn't always mean equity. Sometimes to be fair, you need to treat people/groups differently based on their needs.",
"Equality is the same input, equity is the same result.\n\nEquality would be giving every needy household a 5 lb. bag of rice. Each household gets the same.\n\nEquity would be giving 2 lb. for every adult and 1lb. for every child in that household so that everybody gets enough food. Clearly, not all households get the same, but the result is that each person has the same result."
] |
what keeps our bodies from decomposing before we die?
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[
"You can absolutely start decomposing while alive! We call this necrosis and it smells absolutely revolting\n\nWhen a cell is faced with some kind of stressor, such as bacterial/viral infection, injury, chemical changes, etc., its membrane dissolves and it basically explodes. If a bunch of cells explode in sequence, you end up with a dead area of tissue. This is because when the initial cell explodes, it releases inflammatory and corrosive compounds that affect other, healthy cells. People can survive with incredible amounts of necrosis; I've seen patients with partially mummified extremities still attached to their bodies. Necrosis can occur just about anywhere in the body. \n\nWhat determines subsequent death is how critical the necrotizing tissue is for life, as well as the propensity for infection. Necrotizing tissue can spread infection and even alter the pH of neighboring tissue. More often than not, infection or more specifically sepsis, will claim the person's life. \n\nThe body does perform a regulated version of necrosis called apoptosis. This can be thought of as a \"scheduled cell death\". Some cells that complete their life cycle undergo programmed death. This is how we can more or less \"regenerate\" an organ every few years, without it getting bigger. We also see apoptosis during the development of a fetus (that's why we don't have webbed skin between our fingers!). The difference is that with apoptosis, cell contents remain within the deceased cell membrane and only scheduled cells die.\n\nP.S. lemme know if you wanna go to the next level",
"I'm not an expert, but nothing prevents our bodies from falling apart. Our bodies are constantly destroying old cells and recycling them to make new ones.\n\nAs far as external factors, a lot of decomposition occurs from 'decomposers' such as bugs, fungi, and microscopic life. Normally, our skin stops that stuff from getting inside, and if the stuff does get in, then our white blood cells destroy it. If our bodies can't take care of that, then we get sick, which can lead to death and decomposition. They're always trying!",
"Our immune system, which constantly attacks foreign organisms that try to live inside us.\n\nAlso, trillions of friendly bacteria that live in and on us, and that fight off others.",
"Constant renewal of cells. Some die and some are created.",
"We are all food for worms, and life is just the cellophane keeping us fresh until we're ready to be eaten.",
"Decomposing is our body being eaten by bacteria. While alive, our immune system is maintaining a balance of bacteria in our bodies and killing any that enter restricted areas. When dead, our immune cells aren't getting the stuff they need to live, so they die, so the balance isn't being maintained and the bacteria win."
] |
Is there a Radio Frequency Camera?
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"Yes, but the resolution is limited by the wavelength. Radio telescopes use multiple dishes and interferometry for increasing resolution, but they need to scan just like single dish telescopes. \n\n[Micro bolometer focal plane arrays](_URL_0_) are becoming used for radio astronomy, but are limited to short wavelengths. Other multi-sensors like the 21cm Multibeam Receiver at Parkes have only 13 sensors which are the equivalent of pixels."
] |
How do pets know their names?
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[
"Only through repetition and reinforcement. They gradually learn that whenever you make this sound, you then pay attention to them.",
"They first learn to connect their name with food, most owners call their pets for food. Scratches and petting feels good for the animal and owners call pets name for attention. The same thing happens with treats, their name is called. So to a pet, when they hear their name, it means something good is going to happen to them, so they come over.",
"Same reason they understand Walkies or Rabbit, tone of voice and the sounds it learns to associate with certain activities, dogs are smart and like to please their owners by cooperating with them."
] |
Why does the WiFi signal get better as soon as you disconnect then connect back to it?
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[
"The network may have multiple access points, lots of devices will connect to a certain access point and hang on until they are kicked off.\n\n & #x200B;\n\nDisconnecting and reconnecting will force your phone to connect to the strongest source.",
"One thing I haven't seen here is that wireless systems are designed to use the least amount of power thats needed.\n\nWhen it is looking for a wireless network to connect to, your phone will turn its wifi antennas on at full, maximum power to find a known network. Once a network is found, your phone will connect to it and then lower its wifi power to what is reasonable and needed to pass data without having to repeat packets.\n\nFor the first few moments, you will probably see a stronger signal before the device adjusts its power usage.",
"When you take your finger and pluck a guitar string, or push a paino key that moves a hammer to hit a steel string, you make a beautiful sound. We learned early on sound is a wave. We know a workbench radio is the same idea with one complication: the radio wave can carry music but it is translated to a high frequency we can't hear but can go a long ways. Then the machine picks up the signal with an antenna and modulates the frequency to a frequency humans can hear (AM, FM too but more details).\n\nYou ever use a radio while puttering around the shop then suddenly the signal gets bad? Play with the bunny esrs, curse the truck that shook the earth, or thee UFO overhead. Hit the dang thing. Suddenly Sinatra is crystal clear as you know it ought to be.\n\nThis is interference. Waves move at different speeds and distort in different materials. \n\n\nMultiply the problem by a million. Wifi. Wifi doesn't work because it's not possible to balance the billion little problems with humans, cats, whatever sitting between you and the source.\n\nBut what if fancy math, like the exact equations made for rocket science, could detect, modulate, predict, adjust, and make a strong connection? \n\nSo you have this dynamic math equation doing 1 milllion calculations based on your real environment. But it all comes from that initial judgement of where you are. Wifi does this. Reconnect and all those equations start fresh and its like: you can't understand the big picture if you took a wrong turn in a cornmaze then can't find a way back for beans. But get transported to the beginning with a map again? Better odds since you aren't ALREADY lost. \n\nThe below factor of connecting to the closest place is one such factor. But wifi technology is predicated on literal rocket science to make the normally unworkable, possible.",
"There are multiple reasons this can happen:\n\n1. Your WiFi router might be set to choose its operating frequency on startup, based on interference with other wireless devices in its environment. So, it might’ve chosen a frequency that was not interfering then, but it does now (e.g. your neighbours started their WiFi router in the meantime). When you reset, it’ll choose a better frequency. \n\n2. Your WiFi router might have limited hardware / firmware capabilities, so after a while its memory / buffers become full and a restart erases them. This usually happens with cheaper ones. \n\n3. Your WiFi router, especially if it’s in a public place like a café or a restaurant, might give out addresses to connected devices for a longer time than neccessary - the default is usually 48 hours. So, if its hardware / firmware supports only 1,000 addresses, it’ll give those out really fast and will run out of new addresses for new customers / devices, until one of them becomes free. The reserved address for a client remains for the 48 hours, regardless the fact that the customer maybe used it for 30-60 minutes and left. So, restarting the router will erase this assignment of addresses, and it’ll once again have 1,000 addresses to give out. \n\nThere are other reasons as well, but these are the ones off the top of my head.",
"The last router I had (for a few years) experienced this really badly. About once a week (or more often) I'd have to reset it as the signals would slowly get worse and worse. It had dual 5ghz & 2.4 ghz bands and often the 5 ghz would disappear completely at some point. After rebooting it would always be just fine.\n\nI finally upgraded to the new better one the cable provider has, and while it's only been a couple of weeks it doesn't seem to have the same issues. \n\nI assume it's similar to other technologies where turning it off and on again, just resets certain things that have gone out of whack at some point during the operation... probably something software based.",
"Also when tech supports suggests to unplug and plug in your modem. It’s not a dumb step that is meant to waste time and annoy you, there is a reason behind it. Most newer modems have Automatic Channel Scan. When your modem boots up, it locks into the channel with the least congestion. \n\nOver time, more and more devices in your area join the channel and bog it down. Rebooting your modem will now automatically connect to the NEW best channel. It’s recommended to reboot your modem once a month for this reason. That’s why unplugging it and plugging it in again is a legitimate troubleshooting step.",
"Truth be told, this is too vague of a question and there are a lot of really good answers. It's sort of like asking \"What's causing traffic on the highway?\" It could be an accident, bad weather or just slow drivers. \n\nThere's a lot of reasons why reconnecting would fix your internet problems. Off the top of my head, your router / device's networking isn't up to date and it was a firmware bug. If not, maybe you were just in a room with a lot of interference and by the time you were done reconnecting you moved rooms (also applies to microwave if your on 2.4 GHz). And your router may be leaking memory. That's where useless data is still being stored in your memory. Resetting your device / router would fix this and improve its performance.\n\nNetworking is really tricky because there's a lot of points in the chain where if one link fails, everything else starts to break down.",
"Routers yell at phones, and phones yell back. In order to save their voice, routers and phones will talk quietly, as long as both things can hear each other. Sometimes, they will talk too quietly, so the phone can be forced to yell at the router to get it's attention. The router may yell back. \n\nSome routers can even pick a direction to yell. But it has to know which direction to yell, so it needs the phone to yell at it and tell it which direction to yell.\n\nSometimes lots of routers are yelling in the same area and the phone has a hard time to understand the correct router. The router may use a different way to talk (change frequency), and this might happen after the phone yells at it.",
"I'm not sure that's actually a thing.\n\nBut if you are getting inconsistent wifi performance, you should check the wifi channel. There are a fixed number of these and if you are using the same channel as a neighbour it can cause issues when you are both using it. On my router I browse into the admin and there is an option to scan and show you which channels are being used and you can change them."
] |
Where does money from FTC fines go? How is it used?
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"Federal fines are paid to the US treasury, where it's used for general government spending. Most agencies don't get to add the money they collect as fines to their budget. \n\nKeep in mind that most settlements report a number that's called a fine in media reports, but may include actual fines paid to the treasury, payments to make those harmed whole (most of the billion dollar settlements with banks went to mortgage bondholders and various foreclosure mitigation programs, for example), or donations to various non-profits who work in the field."
] |
Why does a 1080p Nintendo Switch look great on a 4k TV, but a game in 1080p on a 4k computer monitor look so pixelated and bad?
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"As people have said, distance, but there is another factor.\n\n4K computer monitors are really only designed to display a 4K signal well. When you send a lower resolution signal, they use very basic techniques to upscale the image and this looks bad.\n\n4K tv's on the other hand are actively designed to be able to display a 4K, 1080P, 720P and even lower resolution signals. This is done through dedicated signal processing chips running advanced upscaling algorithms. (Cheap tv's often save money by using cheap chips which do this poorly.)",
"1. Distance. You tend to be way closer to a monitor than a TV\n\n2. TV/Monitor's resolution. Image will always look better when the TV is running at the same resolution as the source content. The TV may SUPPORT 4k, however if a 1920x1080 input source is connected, it will operate at 1920x1080. It's possible that if a 1920x1080 game is being played on a 4k monitor, the monitor is still running at 3840x2160 and the video card is handling upscaling to a 3840x2160 window. This will be the case unless the game in question is running in true fullscreen mode (as opposed to borderless windowed or windowed). If a second monitor is connected and not running at 1920x1080, the card will still be handling upscaling.",
"Distance is my guess. On a tv, while pixel density is lower, you are further back so it appears sharper (pixels appear smaller) on a computer monitor you are closer so pixels appear more pixelated. This is especially apparent on a large monitor and a small tv."
] |
What is an Order Book and Price Level, and how are they different.
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"Do you have context for this? Those are fairly common terms that can mean different things based upon the company , industry, or other factors."
] |
How can a phone send data back to a cell tower antenna if it is miles away?
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"I think that the cell tower has a big antenna to send, and a big one for receiving.\nLike a cinema screen and a telescope\n\nEdit:\nYour phone is like a guy away that observes and does hand gestures, the cell tower does the rest"
] |
Why doesn’t Wikipedia just run enough ads to keep the site running.
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"It is inevitable for a business to have to grant some control to those that finance their operations - it becomes the source of your salary, that budget your sitting on that lets you get a raise, or give a raise, that plan for the new office, of for Friday donuts....all depends on money.\n\nIf you create a channel of money it's _going to have influence_ and I admire Wikipedia to shutting of one that would be ripe for _problematic_ influence. The needs and wants of a corporate sponsor via ads are different than the users themselves.",
"At this point it is a matter of reputation. If they ran ads now after so many claims of never using ads, and so many customers knowing they have an ad free information source, it would look hypocritical and reduce its users.",
"Because ads have strings.\n\nAdvertisers don't want their ad shown with their competitors, or with a topic they disagree with, or ... . The problems are endless. Look at the political scrutiny YouTube is under for placing ads on videos that are too far left or right in the minds of the advertisers. It defeats the whole Wikipedia concept if some topics have better coverage because they are politically aligned the popular direction or \"more ad friendly\". You end up with an encyclopedia with no entry for [1989 Tiananmen Square protests](_URL_0_ ).\n\nThey don't ask often for for a lot of money. Please give it to them if you can afford it.",
"Imagine Coca Cola becomes a major sponsor of Wikipedia. A few years later there is a huge scandal with some ingredient in Coke. Wikipedia should be impartial, but they now have a business relationship with Coke that could be impacted if they don’t toe the line."
] |
100AH battery should charge at 10% capacity tops safely....?
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"Look at the data sheets for the battery because the manufacturer will tell you the data.\nEven for general rules is depend on the battery technology you usel Li-ion is quite different from lead-acid.\n\nA 100AH battery charging at 1.1 amp do not take 2 weeks. If it 1.1A all the time it take 90 hours that is a bit less then 4 days. 2 week would bee around 0.3A",
"_URL_0_\n\nPurely depends on the specific battery... Look at the datasheet for each individual battery as I don't believe there is truly a general equation that can be used to calculate that. I mean depending on the chemical makeup some chemical engineer would have found the highest voltage to safely charge it through some redox chemistry (so go and memorize your half reactions or pull up a table of half reactions to do this with) and then they would measure the internal resistance over a discharge period.\n\n\nFor instance for a lithium ion Battery that charges at 4.2V per cell in series and has a 400mohm internal resistance the maximum safe charging current is 10.5A (however that is about 44 watts which can cause it to heat up very fast and if the battery doesn't have a heat sink capable of handling that much energy then you have to reduce that by adding some resistance in series with the battery). Generally phone batteries are charged at around 12W....\n\n\nAm electrical engineer. I took the bare minimum for chemistry from my school meaning none of my electives were on this topic\n\n\nEdit: a general formula would require the entire combined redox reaction, the number of cells in series, any resistance in series, the thermodynamics of the battery such as how much energy it can radiate away to the environment (which requires the temperature of the environment amongst many other things) and more... As well, a 100AH battery will charge from 0 to 100 in 3.8 days at 1.1A... 2 weeks would mean you are charging at about 0.3A",
"It completely is based on the battery chemistry and what is a good C rate of charge. Lithium is completely different than Lead Acid, which is different from NiMH, etc.\n\nLithium, for example, can tolerate much higher rates of charge than other chemistries, and internal BMS systems keep it from overcharging or charging to quickly with temp monitors and the like.\n\nThere's no particular formula that works for everything. You charge at an appropriate C rate that doesn't damage the batteries long term storage capacity. Any battery you buy should have that information provided in its specifications.",
"**Please read this entire message**\n\n---\n\nYour submission has been removed for the following reason(s):\n\n* Information about a specific or narrow issue (personal problems, private experiences, legal questions, medical inquiries, how-to, relationship advice, etc.) are not allowed on ELI5 (Rule 2). \n\n\nr/radiocontrol\n\n\n\n---\nIf you would like this removal reviewed, please read the [detailed rules](_URL_2_) first. If you still feel the removal should be reviewed, please [message the moderators.](_URL_2_?)"
] |
Why an ulcer blister under your lip hurt 100 times more than a regular blister, cut or wound of any sort.
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[
"Is the question about \"why ulcer at that specific spot hurts more\", or about \"why does ulcer hurt more than blister\"?\n\nNot sure about second one, but as for first - your lip area is a lot more sensitive, because it needs those nerve connections to figure out what you're eating/drinking/touching/etc. Therefore anything hurting there would hurt a lot more than something on, say, your kneecap."
] |
What's the rationale behind extraordinarily long prison sentences? (i.e. 'multiple' life sentences, or 100+ years)
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"In case evidence turns up to negate one sentence. The person is responsible for all the crimes they committed, not just one."
] |
how stock owners pay for stuff
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[
"Generally, executives who receive their compensation in terms of stock are already wealthy enough that they have enough liquid funds (i.e. cash) to live quite comfortably. They also will do periodic selling of small amounts of their stock to cash in on particularly good stock performance. \n\nAlso, company execs are different than the board of directors/majority shareholders of a company.",
"Either dividends, sale of stock, or borrowing against their stock holdings. \n\nIf the company pays dividends, even a small dividend becomes a large amount of money when one owns millions of shares. \n\nSelling stock reduces the portion of ownership, but most founders don't have influence because they own 51% of the company, they often own substantially less than 51%. Rather their influence comes from having super voting shares (which is the case for Google). These shares are converted to normal shares before being sold, so even significant sales don't reduce voting share much, or they have influence because they're the founder and still an officer of the company. \n\nFinally, banks will lend money based on the value of one's shares. The major risk is a large decline in the stock's price means the bank will come take the shares away to sell which usually results in the stock price further declining."
] |
Are there limitations to who you can represent when you’re a lawyer?
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[
"Depends on your jurisdiction (jx). I'll speak from the perspective of a US lawyer. \n\nWhen US lawyers sit for the bar exam (which varies by state), you take an exam that, if you pass, allows you to practice in almost any type of law. For example, I could do civil litigation today, bankruptcy tomorrow, and criminal defense on Friday - that is fine. There is no specific exam for each individual practice area. \n\nProsecutors become defense lawyers all the time. \n\nBut just because you can jump practice areas does not mean you should - lawyers have an ethical obligation to be competent when they practice law. Therefore, if I wanted to jump practice areas from civil litigation to family law, I would have to study family law more thoroughly before I started to take on clients in that area. \n\nRegarding clients, there are times you cannot represent someone because there is a conflict between the prospective client and a current or former client. A US lawyer owes his clients a duty of loyalty. Sometimes, that conflict can be waived. Sometimes it cannot be waived. It all depends on the facts.",
"States exercise authority to regulate the practice of law within their borders under what is called the police power. The police power is one of the reserved powers, meaning the federal government cannot tell the states who gets to practice state divorce law. \n\nAccordingly, to practice state law within a state, you must be barred in that state. That's true for every state. \n\nWhat is practicing law, though? Your mother asking you for advice on filing bankruptcy papers isn't it. Your client asking for help writing a real estate contract isn't it in most states (if you're a licensed realtor). \n\nThere's also exceptions, varying by jurisdiction. For example, if you're in house counsel for a company, and not taking on third party clients. \n\nBut what about the federal government? The police power is a reserved power, but the enumerated powers of the federal government are supreme. So, for example, Congress has the power to implement a patent system under the IP Clause of the Constitution. So Congress also gets to decide who practices patent law. That means the federal government can authorize people within the borders of states to practice patent law without being a member of that state's bar. There's a similar (although different because they have to be licensed in *some* state) rule for immigration attorneys. \n\nAs to the bar exam itself, there's only one bar exam in each state. A large number of states have a shared bar now. Once you pass the bar and get sworn in, there is no restriction on the type of state law you can practice. You just have to do so ethically, and included in ethics is competence. so if you're a divorce lawyer and you take on a DUI case for the first time, that's fine, but you need to make sure there's time to become competent in that area of law. \n\nAs to private/state/prosecutor/defense attorney, this gets quite complicated. When you represent someone you gain what are called conflicts. Conflicts follow you is the basic answer. You cannot represent clients who trigger a conflict.",
"You need to be admitted and licensed under the state bar to practice law within that state (including federal courts within that state, and while there are separate admissions to each district court in that state, the main requirement is to be barred in that state and a resident of that state). There is a separate bar for patent attorneys. There is a process called pro hac vice where you can be specially admitted to a jurisdiction in which you do not reside and are not a member of the bar, subject to additional requirements like having a local counsel as co-counsel, only being admitted for purposes of that case, and not practicing that way frequently enough in that jurisdiction as to constitute a regular practice in that jurisdiction. A prosecutor can be a defense attorney, a government attorney can go into private practice and vice versa. While you can practice in almost any area of law in a state with a bar license, you have separate duties to represent clients competently so your best bet is to specialize in a few areas instead of being all over the map"
] |
How exactly does a benzodiazepine and opiate overdose kill you?
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[
"But how do these drugs actually kill people? When a person smokes, snorts or injects an opioid, the substance enters the bloodstream, then the brain. There it can act on mu-opioid receptors, says Eric Strain, director of the Center for Substance Abuse Treatment and Research at Johns Hopkins University. “Once the drug binds to those opioid receptors and activates them, it sets off a cascade of psychological and physical actions; it produces euphoric effects, but it also produces respiratory-depressing effects,” Strain says.\nAs a result, victims of a fatal overdose usually die from respiratory depression—literally choking to death because they cannot get enough oxygen to feed the demands of the brain and other organ systems.\n\n_URL_0_",
"Both are central nervous system (CNS) depressants. One of the things your CNS is in charge of is telling you to breathe. Opioids and benzodiazepines cause a block in the instructions that say \"breathe\" and you end up suffocating.",
"Theyre a CNS suppressant and respitory suppressant, take enough theyll stop you breathing, and stop all the alarm signals that usually go off when you do that. Fade to black...",
"Benzodiazepines make your body relax and use less oxygen.\n\nOpiates turn off the part of your brain (hypoxic drive) that freaks out when you don’t get enough oxygen."
] |
How does HBO afford such big budget shows or the silly expenditures of shows like Last Week Tonight without ad revenue?
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[
"Cable. Subscription services make bank, especially with how many people are subscribed to HBO lately.",
"the same way as netflix. subscriber revenue and content creation. hbo is old enough to be self sufficient now. but netflix is still burning through cash and has negative profits at times during it's expansion phase.",
"HBO is not a free airway channel, nor a standard cable channel. They are a premium subscription service. They get their money from the subscription fees.",
"It's all about large numbers.\n\nHBO has roughly [140 million](_URL_0_) subscribers globally.\n\nSubscription costs vary with how you obtain it (cable package, HBO Now, other streaming service like Hulu). But let's say, as even a very low estimate, HBO received $1 per month per subscriber on average. That would bring in $140 million per month for a total of $1.6 billion in yearly revenue. They obviously make more than that in actuality, but you can see with such a huge subscriber base that even low rates bring in a lot of money.\n\nEdit: changed example to better make my point.",
"Subscription fees and licensed merchandise. They're also selling streaming rights to overseas viewers. \n\nOn top of that, not all the silly expenditures are a pure loss. John Oliver had the \"largest giveaway in TV History\" when they bought a shitload of medical debt and forgave it. \n\nHBO can use that as marketing for a LONG time to build subscribers and goodwill after any number of fuckups.",
"HBO charges $15-20 per subscriber, which is in addition to one's standard cable bill. Those funds go to pay for their programming, whereas other channels get smaller monthly fees from cable providers and supplement that spend with ad revenue."
] |
Why can't a sitting president be indicted for a crime?
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[
"Because there would be nobody to prosecute him.\n\nIt has happened. Lincoln suspended Habeas Corpus, the Supreme court ruled it was unconstitutional because the President lacks that power in the constitution. \n\nDid he go to Jail? No. Did he even go to court? No. All the people that might have arrested him or prosecuted him work in the Justice Department - they work for the President. So there can be no trial.\n\nThis works both ways, President Lincoln didn't get a chance to defend himself. If there had been a trial, and Lincoln had won, everybody would have said \"They didn't really try to win because they work for him\". Right or wrong, this doesn't work.\n\nRecognizing this, the Constitution handles this special condition with a special sort of court-like process = Impeachment.",
"It's not entirely certain that this is the case, rather, it's what the Department of Justice decided after researching the matter. Opinions ultimately differ, and it hasn't been established, since nobody's tried. Their reasoning is here: [_URL_1_](_URL_0_)\n\n & #x200B;\n\nOne of the arguments raised is that since the president has authority over the justice department, he would be essentially required to prosecute himself (or would have the authority to decide whether or not to prosecute himself). That's obviously impossible to do fairly, so the conclusion is that indictment and prosecution is not the way to address presidential crimes. Impeachment provides an alternative, and once the president is out of office, the conflict no longer applies.\n\nSecondly, it observed that the trial of a president would give twelve jurors control of the presidency itself, and would lead to an impossible situation for the president to both manage his own trial, and govern. Impeachment is again, a political resolution to this.",
"The idea is that dealing with criminal charges and indictments could “unconstitutionally” prevent the executive (president’s) branch from doing their job\n\nWhether or not this is *actually* unconstitutional is more fuzzy and up for debate"
] |
why have planes stopped getting bigger?
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"People want to fly directly to their destinations. In the past airlines focused on a \"hub and spoke\" system where small planes flew between small destinations and major hubs and huge planes could fly between the hubs. The development of long-range, fuel-efficient medium-sized planes enabled more \"point-to-point\" flights where people can skip the connection in a hub (or at the very least reduce two connections to one). These new planes also allow infrequent flights between distant hubs to be replaced by more frequent (meaning more convenient for passengers) flights. It used to be that if you wanted to fly *really* far you *needed* a 747 or A380, just because those were the only planes that could fly the distance, even if it wasn't the ideal size otherwise. Now you can, for example, replace the 747 on that route with a 787 and just fly more frequently.",
"There are few uses for very large planes. Even for passenger routes, the a380 is still struggling as the largest passenger jet because few airlines have routes that need such capacity (when airlines often prefer smaller jets flying frequent and direct flights when possible because that's more profitable).",
"Not enough problems can be solved better with a super large planes than a merely very large one. Bigger isn't better.",
"Because there's absolutely no need for larger aircraft. The AN-225 was built to transport the then-Soviet Buran (their version of the space shuttle) much like the American Shuttle Carrier Aircraft, which was a heavily modified 747, not out of any need for massive transport capacity. Only one was ever built. \n\nThere are many disadvantages to large aircraft. The first is that designing them creates ever-increasing engineering challenges. The second is that massive planes need huge runways to takeoff and and, which means fewer and fewer airports around the world are capable of supporting said aircraft. This is especially true for military transports, which often need to land on makeshift runways made of out of dirt somewhere in the desert or mountains. These airstrips are incapable of supporting massive planes.\n\nAs for commercial use, again, there's simply no benefit for huge planes and no demand for them. Cargo and passenger airlines would much rather have the flexibility of having more frequent flights using smaller planes. This is way more profitable for them. The Airbus A380, the largest passenger plane, was a commercial failure because there was simply not enough demand for planes with that capacity, even on the most popular routes. \n\nIn short, larger planes are harder and more expensive to build, there's no demand for them because they're not economical, they can't get to as many places as smaller planes, and there's nothing you can't do with more smaller planes instead of fewer giant ones.",
"The largest planes race was largely for military use. Since the Cold War changed focus in the 1980s, there has been far less of a need to rapidly carry tanks around the world and far *more* of a need for planes that can land on underdeveloped runways. Megahuge planes like the AN225 are not relevant any more, so budgets have gone in a different direction."
] |
How do researchers know when they have found a new species of an animal and not an already discovered species?
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"multiple factors go into deciding if something is a new species. usually, a color change alone won't be enough, but multiple small changes, or a few big change usually results in a new species.",
"People who find new species tend to be experts in that type of organism so they are familiar with the already known ones and will recognise something that isn't catalogued."
] |
If 25 degrees Celsius (77°F) is a comfortable ambient temperature, why does it feel so cold when you bath in water of the same temperature?
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[
"Water is more effective than air at transferring heat (feeling cold is really just another way to say heat was transferred from you). \n\n\nAir around you (assuming it's not windy) will heat up close to your body temperature quickly. You are now in your little heat bubble. Air doesn't take much energy to heat up.\n\n & #x200B;\n\nBlow a fan on you while it's 25C, and you now feel colder.\n\n & #x200B;\n\nGet into 25C water, and the water will do the exact same thing the air does, try to match your temperature, except that water takes a huge amount of energy to heat up compared to air."
] |
Why are sore throats so bad in the morning?
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"Little bit of speculation, but perhaps because you're dehydrating your throat (your entire body really) plus not washing away any of the bacteria? \n\nYou tend to have worse breath in the morning because everything just sits in place overnight. Additionally I know when my mouth is dry (from not having something to drink for awhile), any sort of pain (canker sore, sore throat, etc) tends to be more painful until I drink something. Combine both of those factors into an 8 hour duration or so and you're not gonna have a good time.",
"Gravity as well; you're lying down so fluids in your body will tend to migrate equally as opposed to moving downward while you are upright while awake. It may not seem much, but just a little more swelling from this will make your already swollen tonsils hurt even more. Same reason why your nose might be stuffy while lying down, and clear up when you sit and then stand up. Fluid prefers to follow gravity. So you can use this principle and sleep on some type of foam wedge or pillows so your head is significantly higher than your torso and legs."
] |
Why do you see two shadows of something when there are two lights?
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"Shadows aren't 0 light, they are *less* light. So when tou have 2 light sources, generally everything is twice as bright, except where the object is in the way, when it is only 1 times as bright."
] |
What is the hard problem of consciousness and why is it so hotly debated?
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"The hard problem, per David Chalmers, is that sentient organisms seem to have what are called \"phenomenal experiences,\" or \"qualia\" - that is, they have internal mental states that are subjectively different for each individual, that those individuals seem to experience just as they experience states based directly on interaction with the outside world, and how and why these states exist and are felt.\n\nBasically, you feel/experience things that cannot be directly linked to your interaction with the world at large when you feel them.\n\nThis is a \"hard\" problem for much the same reason that dualism was/is so confounding for the philosophy of mind - it seems very difficult, perhaps even impossible, to link certain subjective states to well-detailed physical mechanisms.\n\n Take for example the thought experiment of a scientist whose whole life is spent in a black and white room, but whose expertise in the physics, chemistry, neurobiology, etc. of how color is seen is sufficient to say that she \"knows what the color red is\" in every way *except* experientially - that is, by seeing it herself. We could ask, \"does she know what red is?\" and by all *purely materialistic* accounts, yes, she does. But, there is something about the *experience of seeing \"red\"* is not contained in the accounting of *how a human being sees red*, but rather *must be experienced by a human being seeing red*.\n\nThe hard problem, then, is effectively why that difference exists, how it it exists, and in more general cases why some of these subjective qualities seem to arise spontaneously, yet still play the \"felt\" role of states more readily linked to external stimulus."
] |
Why are birds considered dinosaurs instead of dinosaur descendants/relatives?
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"In biology, proper groups of animal species (or plants for that matter) are monophyletic. That basically means a group includes and ancestor and all species descended from it. So by definition all dinosaur descendants are dinosaurs...you can't have a descendant of a group not be in the group.\n\nThe reason we do this is because it's less arbitrary. Instead of picking a bunch of species we think are similar enough to be in a group, we just put everything descended from a common ancestor in the group. \n\nSo birds are dinosaurs because birds are descended from the common ancestor of all dinosaurs. If the dinosaur family tree was an actual tree, birds would be a branch coming off of it, and somewhere pretty high up in the tree too. \n\nNow, that said even outside of proper biological naming, and just in terms of everyday thought, it makes sense to think of birds as being dinosaurs... in fact they are really quite dinosaur-like, and if humanity had developed with a long history of interacting with living birds and living other dinosaurs, I don't think we'd think twice about considering them varieties of the same kind of thing. \n\nTo make an analogy, the situation is very much like that of bats and other mammals. Imagine all you had was some living bats and the bones of extinct elephants and rhinos and other large mammals. You might think of bats as being pretty different. But if you compare bats to the broad sweep of mammals in general, they quite clearly fit into the group as a whole. Birds are basically just the bat-equivalent of dinosaurs."
] |
What happens inside our bodys so that, after some time, we can no longer hold weight in the air
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"It is the ATP-ADP cycle. Your muscles need energy to be able to contract, in the case of the video his shoulder, forearm, and bicep muscles were all contracting to support the weight of the pylons.\n\n & #x200B;\n\nHis muscle cells were using ATP along with glucose to contract, which turns the ATP into ADP. But his body only has so much ATP and the rate at which his muscles was turning it into ADP was faster than his body can turn it back. Also, the process of turning ATP into ADP produces hydrogen ions, which in turn creates lactic acid. This is the burning sensation you feel when your muscles are starting to fatigue.\n\n & #x200B;\n\nSo in the end there is no \"fighting through the pain\", eventually your body just runs out of the resources to contract your muscles and your hand just lets go.",
"My best understanding is that it’s muscle fatigue. Your muscles can only handle stress for a certain amount of time before they fail. The bigger the muscle the longer it will work for short bursts. But eventually, it can no longer hold because you’ve used up all of its strength and it will need to recover before being used again. It’s a temporary burst of energy that can be used up, and you will need to eat protein to heal them faster. \n\nThink of it like a rope. The more it’s used, the more the rope starts unwinding and looking all worn before it breaks. Same thing happens with muscles but at a way faster rate because we require energy to survive and the rope doesn’t."
] |
What does the term “uncanny valley” mean?
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"Vsauce channel on youtube has a verry good video and explanation of this...check it out. Btw: All of Michael's videos are awesome\n\n_URL_0_"
] |
How does anesthesia work during a liver transplant?
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"Nobody really knows how anaesthetic agents work, including anaesthesiologists. There are a few theories though."
] |
how do milkshake mixer machines stay clean?
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"The spindle is stainless steel with a small little plastic agitator on the end. Milkshake doesn't tend to stick to the stainless very well and if you give the thing a little spin as you take it out of the milkshake but before it clears the lip of the mixing cup it just flings whatever is still on it into the cup. \n\nWhat you're missing however is that unless they're removing the spindle and washing it between uses, there is still a little bit of milkshake residue on it and a little that gets splattered on the machine itself. Not a huge health issue since only untouched virgin ingredients touch it, but could be a small (unlikely but serious) issue for anyone with a food allergy like strawberries and you just made a strawberry milkshake.",
"I used to work at Baskin Robbins back in the day.\n\nPart of the procedure for making milkshakes was the cleanup afterwards. The steel cup used was rinsed, filled with water, then mixed for a few seconds, washing off the agitator arm.\n\nI'd imagine at a place where they made a lot of milkshakes, they might skip this step, as the residue from one milkshake isn't going to do any harm to the milkshake made a few minutes later. Hopefully htey clean it art the end of shift, though."
] |
If an asteroid is on a perfectly tangent line with the Earth’s surface, is it possible for it to roll along the Earth rather than just collide and stop?
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"The Earth's gravity combined with aerobraking from the atmosphere would pull it in and down. A straight tangential line isn't possible."
] |
Why are there so many website url extensions (eg; .com, .org, .net) and no universal one ?
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[
"TLDs *(Top Level Domains, what you called extensions)* are usually ruled on a nation-wide level. And as we know the world can never agree on something and everybody wants to do their own thing. So there's that.",
"Top Level Domains (TLDs) were originally designed as a way to help organize everything out there. .gov for government, .edu for education, .com for commercial (and as catchall), and so on.\n\nThere weren't really strict rules about who could get or ask for what, so this only sorta worked, but .com became the default for most stuff anyways. If you were around in the mid-late 90s, .net and .org were at one point pretty popular (especially if someone else already owned the same name but with .com), but they mostly fell into disuse during the \".com boom\" era as .com became the \"default\""
] |
why do flamingos stand on one leg and do they have a dominant leg?
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"It is a resting behavior. They spend a good deal of their lives in the water and can sleep in that position. As for dominant leg most creatures have a dominant side, this is more obvious with creatures with hands. \n\nAnd I am certain that flamingos don't think about it. Having worked with them for years I can tell you that they are some of the dumbest birds on the planet. You catch / trap flamingos by walking in the opposite direction you want them to go and can literally walk them into a cage.",
"Flamingos don't have a dominant leg, neither any other bird species have. Researchs has shown us that the bird family including chickens, gooses, swans and ducks stand on one leg to minimize their heat loss, while doing that, they balance their gravity center to not fall and hurt themself."
] |
How did people train for running long races before computers? Specifically, how did they know the km distance of their training runs in order to follow a training plan?
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"Get in a car, set the trip odometer to 0. \n\nDrive desired route, see the miles.\n\nDo math to convert miles to KM - multiply the number of miles by 1.6"
] |
Why can’t phones and computers charge almost instantly when you plug them in, instead taking 2-3 hours?
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"Electricity is stored in batteries as chemicals held in two different containers separated by a filter-y thing. Letting electrons flow from one to the other through your phone (for example) is how it discharges.\n\nForcing the chemical reaction to go backwards is how it recharges, by way of a smaller circuit connected to the charger.\n\nIf the reaction goes too fast, it catches fire.\n\nThis is annoying, and so coming up with a clever (and cheap) solution is an ongoing challenge in electrochemical engineering."
] |
why is carbo-loading before an event supposed to give me energy, yet I never have any energy despite eating mostly carbs
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"A lot of your reasoning here is an oversimplification of complex nutritional concepts.\n\nLet's start with how your body processes carbs. A carbohydrate is a chain of sugar molecules. Your body breaks down the chain into individual sugar molecules, which then go into your blood, which feeds your cells, and gives you energy.\n\nYour body always needs energy, so you need sugar in your blood at all times, but too much sugar can damage your cells. Because of this, your body has a way of storing sugar when the levels get too high, and releasing stored sugar when it gets too low. When blood sugar gets too high, your body releases the hormone insulin. Insulin takes the sugar in your blood and stores it as glycogen molecules. Glycogen is basically just long chains of sugar molecules that are stored in your muscles and liver. When blood sugar gets low, your body releases the hormone glucagon, which breaks apart the glycogen molecules into sugar again, which raises your blood sugar levels.\n\nCarbo-loading is done by althetes in endurance sports to top-up their glycogen levels to the maximum. Since the althete will need continuous, high-levels of energy for a long period of time, this is very important to keep their blood sugar up, and their energy levels up.\n\nNow on to you and your low energy. What kinds of carbs you eat is very important. Do you eat complex carbs, or simple carbs? \"Simple carbs\" are short chains of sugar molecules (found in refined sugar, soda pop, white bread). \"Complex carbs\" are long chains of sugar molecules (found in vegetables and whole grains). Your body is able to break down simple carbs much faster than complex carbs, which quickly raises your blood sugar level. Your body triggers the release of insulin in response to deal with the high sugar levels, which causes your blood sugar levels to quickly drop. Therefore you feel energetic for a short period of time, followed by a sudden decrease in energy. This is probably the cause of your low-energy levels. Complex carbs take longer to digest, so they release sugar into your blood consistently and slowly, thus avoiding high amounts of insulin from being released. The result is that your energy levels are much more stable for a long period of time.\n\nIn summary, eat your fruits and vegetables, and avoid processed foods!",
"Well, in the heat of the moment, when they've warmed up and are ready to go, adrenaline kicks in when they're in action, but that only lasts so long, and the muscles need fast energy for the duration."
] |
what is the butterfly effect?
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"It refers to \"one small change can have dire and catastrophic consequences\"\n\n\"kill one butterfly in the past, ww3 in the future\"\nCan explain a crazy chain of events that COULD happen if the right sequence is triggered. A popular video game that utilizes this trope is the horror game \"until dawn\", where every action you take has the possibility to have disastrous effects\n\nExample: say you traveled into the past. Like, a billion or so years. You saw an almost lizard like animal crawling about and you accidentally step on it, killing it instantly. You think nothing of it and go about your day, eventually coming back to the future. What you find though, is that lizards no longer exist because when you traveled into the ancient past, you accidentally killed the original female organism that would eventually become a modern day lizard. So now lizards don't exist because of one small event that took place.",
"I always heard it that a butterfly flapping its wings on one side of the world could cause a hurricane on the other side if the conditions were just right. But yeah, one tiny change somewhere could cause very large change somewhere else.",
"The idea is that one small event can have a big impact. Like if a butterfly flaps its wings in China, that small ripple in the air could compound and create more ripples, which would make small changes in the winds over the Pacific, which would pass over the United States and eventually, weeks later, result in a tornado in Kansas. If the butterfly hadn't flapped its wings and made that one tiny impact, the tornado and all of its consequences may never have happened.\n\nIt's often associated with time travel, because it's easy to say \"Oh, if I had a time machine, I would go back and kill Hitler, preventing World War II and the Holocaust.\" But it's hard to imagine all the consequences of such an action - if Hitler died, World War II might not have started in 1937, but something else would happen within Germany and the rest of Europe, and for all we know an even worse dictator may rise up and cause even more harm to the world, something that may create an even worse future. \n\nThe reason that a butterfly is used is often credited to the short story \"A Sound of Thunder,\" by Ray Bradbury. In the story, a company offers dinosaur hunting through time travel, but with very strict rules - the hunters must walk on a levitating path that is set up to avoid stepping on anything in the past, the only dinosaurs that may be shot are ones that are known to die in the next few moments anyways - ones who will be crushed by falling trees or fall dead of hunger, and which therefore won't have a major effect on the future. The main character of the story, though, gets scared and steps off the path, crushing a single butterfly, affecting the future in ways they couldn't possibly predict.",
"The butterfly effect is if you were go into the past and change one tiny detail, it would drastically change the future."
] |
If you're stranded in the middle of the ocean and start to feel dehydrated, why is just drinking the seawater around you bad? Why will it not hydrate you?
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[
"Osmosis. Salt water has more salt in than the cells in your body and your blood. So instead if drinking salt water and the water being absorbed, it actually gets drawn out of cells towards the saltier water. You end up peeing out more than you drink because the kidneys can't concentrate the urine more than the salt water, instead water is drawn out into the urine so you lose water.",
"The salt content will go into your system and dehydrate your cells. So you will initially feel quenched, but you will rapidly become dehydrated because of the salt in the water"
] |
What is a schizoaffectice personality disorder? How does it affect a relationship? Do you have any experiences with being in a relationship with someone who has a sad?
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[
"In terms of mental health, SAD is an acronym typically reserved for Seasonal Afflictive Disorder, which is something different. Schizoaffective disorder is basically like schizophrenia and bipolar disorder had an angsty child together. Its manageable, but it never goes away. I would imagine that it would make for a strenuous at best relationship for both parties. My cousin was diagnosed with schizophrenia, went off meds, and is currently and probably permanently hospitalized. My mother had bipolar disorder. Just imagining them together in one person, even when its not at the worst, would be hard to cope with. Any kind of depressive disorder makes maintaining a relationship painful to both parties, and far too few people understand that depressive disorders isn't just someone feels sad, and they have no control over it so they can't just think happy thoughts and make it all rainbows and sunshine. Just being alive is sometimes a struggle. That has a way of wearing down anyone, and yes I mean anyone even if they genuinely and truly love you from the bottom of their heart. Counseling, appropriate medication, and as odd as it sounds a good hobby are all helpful for coping, but it's going to be hard."
] |
Why was it custom for men and children to wear suits, ties and other smart clothing during the 1900's?
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[
"That was just the style back then. You always had to look your best when going out in public.\n\nEdit: I had a neighbor years ago who was born in the 1910s, I believe and he'd put on a suit, tie and hat to go to the mailbox.",
"That’s what they had. Like an earlier poster said, knit fabrics were not yet being produced on an industrial scale, zippers weren’t invented yet and elastic was far less common. So the suits that seem like a “smart” option today are really just the hoodie and sweats of yesteryear. Even a tie was less formal and more just practical— think of it as being just a narrow scarf to hold your collar shut.\n\nAnd about hats: Sometimes I wonder if we’ve really become more practical, or just traded on trouble for another. I’m a woman so i sometimes think... well, back in those ol’ days, I wouldn’t have had to worry as much about my hair because I’d be wearing a hat (ladies were never required to remove their hats—indeed they were often pinned into the hair). We wouldn’t have to worry about our manicure, because we’d be wearing gloves. We wouldn’t have to shave our legs, because stockings. No need to worry about body shape because corsets shaped you. Clothes might have been uncomfortable back then, but at least you didn’t beat yourself up over bod maintenance.",
"Most people worked on farms or in factories and wore work clothes. If you had a white collar job you were in a prestige occupation. Maybe not much prestige but at least you weren't shovelling shit and hollering 'whoa'.\n\nAnd if you did have a blue collar job you would dress up for church, and social occasions unless you were an out and out hobo.\n\nTo put it another way, in those days you dressed up to look rich. Today if you are rich you prove it by dressing like a hippie or a tramp."
] |
Honestly, how does time, or the concept of “time,” even work?
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[
"Could you explain what you're asking? Time is simply the fact that all things doesn't happen simultaneously",
"the universal idea of time that most people think of on a daily basis has existed for as long as humans have. it better helps us to communicate ideas and order events so that we can all function together. \n\nwith the discovery that time was in fact NOT universal for everyone but depends on your own personal speed and direction of motion comes a lot of “discomfort.” it’s really weird to think that you will age less traveling in a spaceship to a distant world than your twin sibling who is left back on earth. \n\nso what is time? physicists will sometimes say that we live in a “3+1 dimensional universe” meaning that we have 3 spacial dimensions and one temporal (time). we can see that there seems to be a distinct direction that time flows in when you start thinking about more complex concepts like entropy. but really i think the simplest way to wrap your head around it is to think of existing in 3d space and moving forward in time as being one in the same. it’s weird to think of but measuring time is arbitrary and done for the sake of communicating results to others. when it comes down to it, your movement in space isn’t different from your position on a timeline. this concept is so difficult to explain or understand because of the fact that time is intangible. \n\nand the thing about black holes... space and time are united as “spacetime” and form the base for the entire universe. objects that have mass can warp this fabric of sorts and cause distortions in the experience of time. extremely massive, dense objects like black holes cause dramatic distortions. if i am falling in a black hole and you are on a rocket where you are trying to receive a ping from me every second, as i fall in, the closer i get to the singularity, the harder it is for my signal to reach you and to you there will be progressively longer delays between each signal (the ping can only travel as fast as light which isn’t enough to escape the black hole). eventually, i will fall far enough that gravity’s pull is too great for light to escape and you won’t receive a ping from me again. \n\nthere is a really really cool youtube channel called minutephysics if you’re interested in this kind of thing! there is a playlist about special relativity that honestly explains this soooo much better than i or anyone could. the visual representation given helps a lot. also maybe check out pbs spacetime!! their videos are fascinating and both channels have really inspired me to try to make physics my field of study. \n\nsorry for the long response i thought this question was so interesting and thought provoking and i realize my response is a bit... all over the place.",
"It’s a Good question. People have been trying to figure that out for a long time. \nThat’s part of the premise of general relativity which is still surrounded by question marks.\n\nI feel like there’s so much I could say about time. \n\nAn interesting tid bit one of my professors discussed with me once Is that time and distance are really the same thing. You can measure a distance by an amount of time (e.g. miles/hour) or even time by a distance if you think about it.\n\nSo at its essence maybe the most concrete thing I can say about time is that it’s like another dimension. \n\nOur 3D world moves through the dimension of time in only one direction though. \n\nWe travel through time maybe like how fish travel through water— they don’t really know they’re in it and that it’s separate thing of itself.",
"Time is what we use to describe observed changes in three dimensional space. Think of time as being part of a coordinate system. If you have a line, you need some way to describe different points on that line. That's one axis. If you have a flat surface, you need another axis. For a 3d object, you need a 3rd axis. That's space as you're familiar with that uses x,y,z coordinates. Now if things change in that 3d space, you need a way to describe that too. That's time, which is a 4th axis. That's why we we talk about spacetime as being interconnected and inseparable. You can't describe a change in space without time, and there's no time without space.",
"Look into parameterization, then consider treating time as a fourth spacial component.\n\nYou could consider time to be an independent variable, and the three spacial dimensions are dependent upon the time variable.\n\nTime is what permits the transition from cause to effect."
] |
How do charitable promotions work a large stores?
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"Yep you are right. Lets think of an item. This item costs the store 8$ then the store sells it for 11$. So the difference there is 3$. Of the 3$ let's say 2$ goes towards employee salaries and business expenses. Then 1$ is the profit. If the business is saying they give 10% of profit sold to charity it means 0.10$.\n\nEdit: mobile mistakes and confusion",
"They track total sales of whatever good and the company pays the amount at the end of the promotion. They’re not cutting penny or buckle checks with every purchase. And they’re not tracking the literal item “sold”, they’re counting totals... so if 200,000 of an items sells to customers between the dates they pay that, not what’s fed into the wholesale distribution channel."
] |
How exactly is a calorie "burned"?
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[
"From a chemistry standpoint, they mean it quite literally. \nA calorie is a unit of energy. \nThis energy is stored in the chemical bonds of a molecule, almost always in a molecule of carbon, oxygen, and hydrogen. \nWhen you eat and digest it the food, it turns into one of those molecules your body can burn for energy. \n \nWhen you burn the calorie, you add oxygen, and the carbon-hydrogen-oxygen atom turns into carbon dioxide and water + energy form the bonds freed. \nThis is chemically identical to regular burning. \n \nYou then exhale the carbon dioxide. \nThe CO2 you are exhaling weighs more than the O2 you are inhaling. \nThat's where your weight goes.",
"All your cells use energy, constantly, all the time. When you exercise, they use more energy.\n\nBecause calories are a measure of energy, you can measure the energy used by the cells with the unit of calories."
] |
Why aren’t you supposed to cut the tags off your mattress? What happens if you do?
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[
"That's just for the retailer. It has important fire safety notices for the consumer.\n\nI'm pretty sure it's a Federal crime to remove the tags unless you're the owner."
] |
Why does WiFi in a house or office still suck in an age where we can have a drone transmit a WiFi HD video signal from a mile away?
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[
"I wouldn't say WiFi really sucks.\n\nIt all depends on the setup you have: if you have a sufficient number of access points (antennas), or if the ones you have are strong enough. Your house plays a big role in this as well, thicker walls means a bigger loss in signal strength. There's two frequencies used right for WiFi, 2.4 GHz (slow but penetrates walls better) and 5 GHz (fast but bad wall penetration).\n\nAll this to say if you have a decent router (not the one your ISP sends you) and you place it at the right spot, you'll be just fine. Maybe add a few repeaters or install a mesh network if you have a bigger house. \n\nFor drones, it's simply because usually they're transmitting in open space (outside) and have only one connexion. It's using a different type of transmission which is more suitable for distances bigger than the size of a home.",
"I can start by saying this is my speculation. \nFor the range I’m assuming there is some kind of pairing at the start of flight. It is possible this pairing sets a very specific frequency which the controller and drone have a radio frequency filter to only see that frequency. It’s kind of like a pane of green glass only letting green light through, you can’t see the green in the white light until filtered. The white light being filtered could be anything, other WiFi, radio, cell towers, every piece cut makes it easier to get signal. After it is filtered to only see the drone signal, it can then be amplified, either on the transmitting, receiving, or both. \nAs for the video, I doubt it is streaming the full quality video to the controller. For the full quality from the camera, you will likely have to pull the sd card, the video on the controller would be as good as the signal can get it.",
"WiFi routers are a radio transmitter and they are restricted in their range by law how far they can broadcast (depending on the protocol from about 20m to about 100m but it depends on if they are going through concrete walls etc) to prevent them from interfering with other radio signals.\n\nSo it's actually built into the law. If you have a large house and you need a good signal over 25m from the source then you need to look into a WiFi repeater that repeats the signal for another 25m / 50m.\n\nIt's trivial to increase the signal strength: you just inject more power basically. But it's not a technology issue, it's a regulatory issue.",
"Probably because we havent updated stuff to that level and doing that is surely pretty expensive."
] |
How does going through an emotional episode (ex. heavy crying) physically exhaust the body, when you’ve likely stayed mostly stationary throughout it?
|
[
"While your body was stationary, your muscles inside your body were not. Your heart was pumping faster, andrenaline was being injected into your muscles, you were tense, etc.\n\nAndrenaline itself is well known for leaving the muscles feeling tired once it leaves.",
"Each time you sob, you flex a lot of muscles so it can be physically draining. And having an emotional outburst can make you *feel* drained as well."
] |
How do micro organisms survive in the stomach?
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[
"There a many many many different types of bacteria. A lot like environments that have neutral acidity, normal temperatures, and low levels of salt. However then there are some types of bacteria (called extremophiles!) that like high temperatures or high salt levels or acidic or basic environments. The acidophiles (extremophiles that specifically like acids) grow best or at the very least tolerate acidic environments.",
"The acidity in your stomach is about on par with lemon juice. Acid but not burn a hole acid",
"They have special enzymes that help them cope with the acidity. For example, a bacteria which commonly causes stomach ulcers (H pylori) uses an enzyme to break down urea into ammonia and carbon dioxide. The ammonia is an alkaline which kinda neutralises the acid surrounding the bacteria. Therefore letting it survive."
] |
Why is fiberglass not considered as dangerous as asbestos?
|
[
"Asbestos fibers are small - really, really small. They can easily get past the body's defenses to particulates (mucus membranes, fine nasal hair, etc.) and settle deep in the lungs, where they cannot be removed by any biological process. These fibers persist and irritate the lungs, leading in many cases to a particularly nasty form of cancer (mesothelioma). Asbestos is also easily friable, meaning small disturbances to installed asbestos produce huge numbers of tiny airborne fibers. The combination of friability, easy passage to the deep parts of the lungs, and carcinogenic impacts makes asbestos particularly hazardous to human health.\n\nFiberglass also produces particulate matter, but it's much, much larger (typically) than asbestos fibers, so your body stops most of it from entering the lungs. While it's an irritant, it is not carcinogenic. So, it's bad, but not nearly as bad as asbestos.\n\nSilica, especially in foundry and blasting work, leads to silicosis, which is also bad, but not (typically) as bad as asbestosis and mesothelioma. Coal dust leads to black lung - also bad, but not in the same league as asbestos.",
"Well I know that the asbestos fibers are so fine and light that they float invisibly through the air and destroy your lungs if you breathe them in.\nI think fiberglass stays in larger pieces and doesn't become razor sharp dust",
"The bad part about asbestos is that some of the components are carcinogens. Although a fiberglass sliver does suck.",
"Asbestos is a known carcinogen (a substance that can increase the risk of or cause cancer) and it also has a smaller size relative to most fiberglass particles (asbestos ranges from 3-20 microns on average). While some fiberglass materials have particles this size, most of them have a greater width (100-1000 microns) that are too large to pass through the nose/throat to the lungs. The cutoff is approximately 10 microns for entering the thoracic cavity.",
"Asbestos causes cancers in addition to irritations from its fibers. Fiberglass does not cause cancers and so it is not as dangerous."
] |
Why do sad situations make it feel like our hearts are actually hurting, when it's just an emotion.
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[
"When faced with stressful situations (includes situations that make us sad, like a break-up, or a death of a loved one), the body produces fight-or-flight hormones. These have an effect on the blood vessels on the heart, raising blood pressure and increasing heart rate, which all increases the stress on the heart. Sometimes, these can cause the blood vessels to spasm, periodically cutting off blood supply to a particular part of the heart. This causes the heart pain you feel.\n\nWhen the heart is faced with this situation repeatedly over a long period of time, the heart becomes weaker and is less able to pump enough blood to supply the body. This condition is known as Takatsubo’s cardiomyopathy or more widely known as broken heart syndrome.",
"People often times forget the effect that pain and stress has on your muscles. The reason you can read body language is because the body expresses itself physically. Nervousness causes muscles to flex that raise your shoulders, for instance, and incredibly sad and devastated people seem to (in my own observation) suck their chest in, almost right at the solar plexus.\n\nThe body is complicated, and any stressor effects hormones and blood pressure, but people always forget about our muscles and their empathetic habit of reacting to how we feel.",
"Emotions are understood to be \"musical variations of primordial sensations\" according to Bessell Van Der Kolk in \"The body keeps the score\". Which is to say emotions are our frontal cortexs interpretation of layered signals from out entire body. \n\nIt is now known that when someone remembers a memory, their body responds internally with those same primordial sensations it did at time time of the event. \n\nThere is no \"just\" to emotions. They are part and parcel of our conscious self which is believed to come from the background information about how we're doing so we can decide what to do with that information.",
"Feeling sad is a kind of stress. Stress makes your body do lots of wonky things. One of those things is making your heart beat faster or heavier. When you're sad you're not moving around very much, so all that extra blood doesn't do any good, so your chest hurts because your heart is working too hard."
] |
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